Publications by authors named "Luca Sebastianelli"

50 Publications

Effects of Intermittent Theta Burst Stimulation on the Clock Drawing Test Performances in Patients with Alzheimer's Disease.

Brain Topogr 2021 Apr 8. Epub 2021 Apr 8.

Department of Neurology, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria.

The clock drawing test (CDT) is widely used in clinical neuropsychological practice. However, its neuroanatomical correlates have not been well established. This study investigated the effects of theta burst stimulation (TBS) applied over different brain regions on CDT scores in patients with Alzheimer's disease (AD). The 10-20 positions F3, F4, T3, T4, TP3, TP4, P3, P4, as determined by a 10-20 positioning cap, were targeted. Excitatory intermittent TBS (iTBS) was given over the above-mentioned eight regions to ten AD patients and ten control subjects on separate days. CDT was administered at baseline (T0), during the 5 min following the TBS (T1) and 60 min after TBS (T2), with an inter-session interval of at least 4 days. iTBS over TP4 and P4 transiently increased Rouleau CDT score in AD patients. When targeting TP4 and P4, mainly the area of the supramarginal/angular gyrus and the inferior parietal lobe, corresponding respectively to the Brodmann areas 40/39 and 7/40, are reached. iTBS thus seems able to modulate activity of the right posterior parietal cortex in AD patients performing the CDT. Our results provide physiological evidence that those parietal regions are functionally important for the execution of the Rouleau CDT. This finding suggests that CDT has reliable neuroanatomical correlates, and support the notion that this test can be used as a good marker of right parietal brain dysfunction. The present study also highlights the therapeutic potential of the induction of neuromodulatory effects using non-invasive brain stimulation techniques.
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http://dx.doi.org/10.1007/s10548-021-00836-2DOI Listing
April 2021

Intracortical GABAergic dysfunction in patients with fatigue and dysexecutive syndrome after COVID-19.

Clin Neurophysiol 2021 05 13;132(5):1138-1143. Epub 2021 Mar 13.

Non-Invasive Brain Stimulation Unit/Department of Behavioral and Clinical Neurology, Santa Lucia Foundation IRCCS, Rome, Italy; Department of Neuroscience and Rehabilitation, University of Ferrara, Italy.

Objective: A high proportion of patients experience fatigue and impairment of cognitive functions after coronavirus disease 2019 (COVID-19). Here we applied transcranial magnetic stimulation (TMS) to explore the activity of the main inhibitory intracortical circuits within the primary motor cortex (M1) in a sample of patients complaining of fatigue and presenting executive dysfunction after resolution of COVID-19 with neurological manifestations.

Methods: Twelve patients who recovered from typical COVID-19 pneumonia with neurological complications and complained of profound physical and mental fatigue underwent, 9 to 13 weeks from disease onset, a psychometric evaluation including a self-reported fatigue numeric-rating scale (FRS, Fatigue Rating Scale) and the Frontal Assessment Battery (FAB). Intracortical activity was evaluated by means of well-established TMS protocols including short-interval intracortical inhibition (SICI), reflecting GABA-mediated inhibition, long-interval intracortical inhibition (LICI), a marker of GABA receptor activity, and short-latency afferent inhibition (SAI) that indexes central cholinergic transmission. TMS data were compared to those obtained in a control group of ten healthy subjects (HS) matched by age, sex and education level.

Results: Post-COVID-19 patients reported marked fatigue according to FRS score (8.1 ± 1.7) and presented pathological scores at the FAB based on Italian normative data (12.2 ± 0.7). TMS revealed marked reduction of SICI, and disruption of LICI as compared to HS. SAI was also slightly diminished.

Conclusions: The present study documents for the first time reduced GABAergic inhibition in the M1 in patients who recovered from COVID-19 with neurological complications and manifested fatigue and dysexecutive syndrome.

Significance: TMS may serve as diagnostic tool in cognitive disturbances and fatigue in post-COVID-19 patients.
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http://dx.doi.org/10.1016/j.clinph.2021.03.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7954785PMC
May 2021

TMS-EEG Co-Registration in Patients with Mild Cognitive Impairment, Alzheimer's Disease and Other Dementias: A Systematic Review.

Brain Sci 2021 Feb 27;11(3). Epub 2021 Feb 27.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, 5020 Salzburg, Austria.

An established method to assess effective brain connectivity is the combined use of transcranial magnetic stimulation with simultaneous electroencephalography (TMS-EEG) because TMS-induced cortical responses propagate to distant anatomically connected brain areas. Alzheimer's disease (AD) and other dementias are associated with changes in brain networks and connectivity, but the underlying pathophysiology of these processes is poorly defined. We performed here a systematic review of the studies employing TMS-EEG co-registration in patients with dementias. TMS-EEG studies targeting the motor cortex have revealed a significantly reduced TMS-evoked P30 in AD patients in the temporo-parietal cortex ipsilateral to stimulation side as well as in the contralateral fronto-central area, and we have demonstrated a deep rearrangement of the sensorimotor system even in mild AD patients. TMS-EEG studies targeting other cortical areas showed alterations of effective dorsolateral prefrontal cortex connectivity as well as an inverse correlation between prefrontal-to-parietal connectivity and cognitive impairment. Moreover, TMS-EEG analysis showed a selective increase in precuneus neural activity. TMS-EEG co-registrations can also been used to investigate whether different drugs may affect cognitive functions in patients with dementias.
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http://dx.doi.org/10.3390/brainsci11030303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7997266PMC
February 2021

Prepulse inhibition vs cognitive modulation of the hand-blink reflex.

Sci Rep 2021 Feb 25;11(1):4618. Epub 2021 Feb 25.

Department of Neurology, Hochzirl Hospital, Zirl, Austria.

The excitability of brainstem circuitries mediating defensive blinking in response to abrupt sensory inputs is continuously modulated by cortical areas, e.g., the hand-blink reflex (HBR), elicited by intense electrical median nerve stimulation, is enhanced when the stimulated hand is close to the face, with the behavioural purpose to optimize self-protection from increased threat. Here we investigated whether such cortically mediated HBR facilitation can be influenced by prepulse inhibition (PPI), which is known to occur entirely at the subcortical level. Twenty healthy volunteers underwent HBR recordings in five experimental conditions. In conditions 1 and 2, the stimulated hand was held either near (1) or far (2) from the face, respectively. In conditions 3 and 4, stimulation of the hand near the face was preceded by a peri-liminal prepulse to the index finger of the contralateral hand held either near (3) or far from the face (4). In condition 5, participants self-triggered the stimulus eliciting the HBR. We observed a reproducible HBR in 14 out of 20 participants and measured onset latency and area of the HBR in orbicularis oculi muscles bilaterally. HBR area decreased and latency increased in condition 2 relative to condition 1; HBR area decreased and latency increased markedly in condition 3, and somewhat less in condition 4, relative to conditions 1 and 2; self-stimulation (condition 5) also suppressed HBRs, but less than prepulses. These findings indicate that PPI of the HBR is more robust than the cognitive modulation exerted by top-down cortical projections. Possibly, an attentional shift to a prepulse may serve to reduce blinking in response to perturbation when it is convenient, in a given situation, not to interrupt ongoing visual processing.
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http://dx.doi.org/10.1038/s41598-021-84241-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7907410PMC
February 2021

Case Report: Myopathy in Critically Ill COVID-19 Patients: A Consequence of Hyperinflammation?

Front Neurol 2021 29;12:625144. Epub 2021 Jan 29.

Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti, Italy.

COVID-19-associated muscular complications may comprise myalgia, weakness, wasting, and rhabdomyolysis. Skeletal muscle damage in COVID-19 may be due to direct infection by the virus SARS-CoV-2 through interaction with the ACE2 receptor, systemic hyper-inflammatory state with cytokine release and homeostatic perturbation, an autoimmune process, or myotoxic drugs. Disclosing the cause of weakness in an individual patient is therefore difficult. We report two patients, who survived typical COVID-19 pneumonia requiring intensive care treatment and who developed early on myalgia and severe proximal weakness in all four limbs. Laboratory exams revealed elevated serum creatine kinase and markedly increased C-reactive protein and interleukin 6, concurring with a systemic inflammatory response. On admission in neurorehabilitation (4 and 7 weeks after COVID-19 onset, respectively), the patients presented with proximal flaccid tetraparesis and limb-girdle muscle atrophy. Motor nerve conduction studies showed decreased amplitude and prolonged duration of compound muscle action potentials (CMAPs) with normal distal motor latencies and normal conduction velocities in median and ulnar nerves. Needle electromyography in proximal muscles revealed spontaneous activity in one and myopathic changes in both patients. Clinical, laboratory, and electrodiagnostic findings in these patients were unequivocally consistent with myopathy. Interestingly, increased distal CMAP duration has been described in patients with critical illness myopathy (CIM) and reflects slow muscle fiber conduction velocity due to membrane hypo-excitability, possibly induced by inflammatory cytokines. By analogy with CIM, the pathogenesis of COVID-19-related myopathy might also depend on hyperinflammation and metabolic pathways that may affect muscles in a pathophysiological continuum from hypo-excitability to necrosis.
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http://dx.doi.org/10.3389/fneur.2021.625144DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7878532PMC
January 2021

The Ties That Bind: Aberrant Plasticity and Networks Dysfunction in Movement Disorders-Implications for Rehabilitation.

Brain Connect 2021 May 9;11(4):278-296. Epub 2021 Feb 9.

Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.

Movement disorders encompass various conditions affecting the nervous system. The pathological processes underlying movement disorders lead to aberrant synaptic plastic changes, which in turn alter the functioning of large-scale brain networks. Therefore, clinical phenomenology does not only entail motor symptoms but also cognitive and motivational disturbances. The result is the disruption of motor learning and motor behavior. Due to this complexity, the responsiveness to standard therapies could be disappointing. Specific forms of rehabilitation entailing goal-based practice, aerobic training, and the use of noninvasive brain stimulation techniques could "restore" neuroplasticity at motor-cognitive circuitries, leading to clinical gains. This is probably associated with modulations occurring at both molecular (synaptic) and circuitry levels (networks). Several gaps remain in our understanding of the relationships among plasticity and neural networks and how neurorehabilitation could promote clinical gains is still unclear. In this review, we outline first the networks involved in motor learning and behavior and analyze which mechanisms link the pathological synaptic plastic changes with these networks' disruption in movement disorders. Therefore, we provide theoretical and practical bases to be applied for treatment in rehabilitation.
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http://dx.doi.org/10.1089/brain.2020.0971DOI Listing
May 2021

Neuropsychological and neurophysiological correlates of fatigue in post-acute patients with neurological manifestations of COVID-19: Insights into a challenging symptom.

J Neurol Sci 2021 01 14;420:117271. Epub 2020 Dec 14.

Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.

More than half of patients who recover from COVID-19 experience fatigue. We studied fatigue using neuropsychological and neurophysiological investigations in post-COVID-19 patients and healthy subjects. Neuropsychological assessment included: Fatigue Severity Scale (FSS), Fatigue Rating Scale, Beck Depression Inventory, Apathy Evaluation Scale, cognitive tests, and computerized tasks. Neurophysiological examination was assessed before (PRE) and 2 min after (POST) a 1-min fatiguing isometric pinching task and included: maximum compound muscle action potential (CMAP) amplitude in first dorsal interosseous muscle (FDI) following ulnar nerve stimulation, resting motor threshold, motor evoked potential (MEP) amplitude and silent period (SP) duration in right FDI following transcranial magnetic stimulation of the left motor cortex. Maximum pinch strength was measured. Perceived exertion was assessed with the Borg-Category-Ratio scale. Patients manifested fatigue, apathy, executive deficits, impaired cognitive control, and reduction in global cognition. Perceived exertion was higher in patients. CMAP and MEP were smaller in patients both PRE and POST. CMAP did not change in either group from PRE to POST, while MEP amplitudes declined in controls POST. SP duration did not differ between groups PRE, increased in controls but decreased in patients POST. Patients' change of SP duration from PRE to POST was negatively correlated to FSS. Abnormal SP shortening and lack of MEP depression concur with a reduction in post-exhaustion corticomotor inhibition, suggesting a possible GABA-ergic dysfunction. This impairment might be related to the neuropsychological alterations. COVID-19-associated inflammation might lead to GABAergic impairment, possibly representing the basis of fatigue and explaining apathy and executive deficits.
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http://dx.doi.org/10.1016/j.jns.2020.117271DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7834526PMC
January 2021

Effects of intrathecal baclofen therapy in subjects with disorders of consciousness: a reappraisal.

J Neural Transm (Vienna) 2020 09 24;127(9):1209-1215. Epub 2020 Jul 24.

Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy.

Baclofen is a structural analogue of gamma-amino-butyric acid (GABA), which reduces spastic hypertonia of striated muscle due to a mechanism of GABA-ergic inhibition of mono- and polysynaptic reflexes at the spinal level. There are reports of patients with severe disorders of consciousness that presented a substantial improvement following intrathecal baclofen (ITB) administration for severe spasticity. The neural mechanisms underlying the clinical recovery after ITB have not yet been clarified. Baclofen could modulate sleep-wake cycles that may be dysregulated and thus interfere with alertness and awareness. The diminished proprioceptive and nociceptive sensory inputs may relieve thalamo-cortical neural networks involved in maintaining the consciousness of the self and the world. ITB treatment might also promote the recovery of an impaired GABAergic cortical tone, restoring the balance between excitatory and inhibitory cortical activity. Furthermore, glutamatergic synapses are directly or indirectly modulated by GABA-ergic receptors. Neurophysiological techniques (such as transcranial magnetic stimulation, electroencephalography, or the combination of both) can be helpful to explore the effects of intrathecal or oral baclofen on the modulation of neural cortical circuits in humans with disorders of consciousness.
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http://dx.doi.org/10.1007/s00702-020-02233-8DOI Listing
September 2020

Transcranial magnetic stimulation and gait disturbances in Parkinson's disease: A systematic review.

Neurophysiol Clin 2020 Jul 30;50(3):213-225. Epub 2020 Jun 30.

Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy.

Transcranial magnetic stimulation (TMS) may offer a reliable means of characterizing important pathophysiologic aspects of motor impairments in Parkinson's disease (PD). Moreover, high-frequency repetitive TMS (rTMS), especially if delivered bilaterally over motor cortical regions, can have beneficial effects on parkinsonian motor symptoms. However, only a few studies have investigated the effects of rTMS on freezing of gait (FOG) and other gait disturbances in PD. We aimed at investigating in this narrative review the usefulness of TMS for exploring the pathophysiology of gait impairment and at evaluating the therapeutic effects of rTMS in this context. The combination of rTMS and treadmill training was found to enhance the effect of physical therapy. Use of an H-coil enables stimulation of deep regions of the brain (for example medial prefrontal cortex) and may be used as a target for add-on therapy in the future. In contrast, theta burst stimulation has proven to be ineffective in treating gait disturbances in PD patients. Dual-mode NIBS, in particular preconditioning motor cortex rTMS by transcranial direct current stimulation, might also represent a novel therapeutic approach for patients with gait disturbances. Recent studies suggest that the supplementary motor area could be an appropriate target for brain stimulation when treating PD patients with FOG. Further large sample and well-designed clinical studies are required to evaluate how the possible positive effects of rTMS can be sustained over time and to determine the optimal stimulation protocols including target, stimulation intensity/duration and number of sessions.
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http://dx.doi.org/10.1016/j.neucli.2020.05.002DOI Listing
July 2020

Altered response to repetitive transcranial magnetic stimulation in patients with chronic primary insomnia.

Sleep Med 2020 08 5;72:126-129. Epub 2020 Apr 5.

Department of Psychology, University of Akureyri, Iceland.

Background: We aimed at evaluating the amplitude changes of the motor evoked potentials (MEPs) induced by of low-frequency (LF) repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) in10 patients with primary insomnia (PI) and in 10 age-matched healthy controls.

Methods: Median peak-to-peak MEP amplitudes were assessed in all subjects at three times: at baseline (T), after the first train of a single rTMS session (T), and after the whole rTMS procedure (T). This consists of 20 trains of 1 Hz stimulation with 50 stimuli per train and an intertrain interval of 30 s.

Results: Resting motor threshold (RMT) and MEPs amplitude did not differ between the two groups at T. A reduction of MEP size was observed at both T and T in all subjects, but this was significantly less pronounced in patients than in control subjects.

Conclusions: The lack of MEP inhibition reflects an altered response to LF rTMS in patients with PI. These rTMS findings are indicative of an altered cortical plasticity in inhibitory circuits within M1 in PI. Subjects with PI exhibited an impairment of the LTD-like mechanisms induced by inhibitory rTMS, thus providing further support to the involvement of GABA neurotransmission in the pathophysiology of PI.
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http://dx.doi.org/10.1016/j.sleep.2020.03.030DOI Listing
August 2020

Understanding hyper-reflexia in acute motor axonal neuropathy (AMAN).

Neurophysiol Clin 2020 Jul 25;50(3):139-144. Epub 2020 Jun 25.

Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti-Pescara, Italy.

Hyper-reflexia is occasionally seen in acute motor axonal neuropathy (AMAN), but its pathophysiology is unclear. We report a patient with AMAN following Campylobacter jejuni enteritis, who showed generalized hyper-reflexia, bilateral Hoffmann sign and right Babinski sign. MRI and transcranial magnetic stimulation of the motor cortex disclosed no corticospinal tract involvement. An extensive electrophysiological investigation documented α-motoneuron hyperexcitability and dysfunction of the interneuronal inhibitory circuits in the spinal anterior horn. We propose an immune-mediated damage of the spinal inhibitory interneuronal network as possible mechanism inducing hyper-reflexia in AMAN.
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http://dx.doi.org/10.1016/j.neucli.2020.05.004DOI Listing
July 2020

Threat vs control: Potentiation of the trigeminal blink reflex by threat proximity is overruled by self-stimulation.

Psychophysiology 2020 10 23;57(10):e13626. Epub 2020 Jun 23.

Department of Neurology, Hochzirl Hospital, Zirl, Austria.

The magnitude of the defensive blink reflex is modulated by continuous assessment of its protective value. Here, we studied whether the trigeminal blink reflex (TBR) is modulated by a potentially offensive object close to the face, and, if so, whether self-stimulation or observation of the act of stimulus triggering counteracts such modulation. In all, 26 healthy volunteers participated in various experimental conditions. At baseline, an experimenter triggered supraorbital nerve stimuli remotely, unseen by the participants; in experimental conditions, the experimenter held a stimulation probe close to the participant's face but triggered the stimuli either remotely, "surprising" participants (S ), or directly on the probe, observed by participants (S ). In other conditions, participants triggered stimuli themselves on the probe held next to their body (S ) or held in front of their face (S ). The latter condition was repeated similarly, but pressing the button only randomly generated electrical stimuli (S5, "Russian roulette"). The size of the R2 component of the TBR (TBR-R2) was the main outcome measure. Compared to baseline, TBR-R2 area was significantly larger in S when the "threatening" probe was close to the face and the participant had no control over stimulation. Conversely, TBR-R2 was suppressed when participants either saw the action of triggering, thus being aware (S ), or had full initiative over stimulation (S , S ). Random self-generated stimuli (S ) inhibited TBR-R2, but to a lesser extent than S and S Perceived threat close to the face facilitates TBR-R2, but knowledge about impending stimulation or self-agency overrules this effect.
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http://dx.doi.org/10.1111/psyp.13626DOI Listing
October 2020

Repetitive transcranial magnetic stimulation in traumatic brain injury: Evidence from animal and human studies.

Brain Res Bull 2020 06 3;159:44-52. Epub 2020 Apr 3.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

We provide here the first systematic review on the studies dealing with repetitive transcranial magnetic stimulation (rTMS) for traumatic brain injury (TBI) in animals and humans. Several experimental studies in animal models have explored with promising results the use of rTMS to enhance neuroprotection and recovery after TBI. However, there are surprisingly few studies that have obtained substantial evidence regarding effects of rTMS in humans with TBI, many of them are case reports investigating the heterogeneous conditions linked to TBI. The most studies have investigated the effects of rTMS in subjects with post-traumatic depression and variable effects have been observed. rTMS has been proposed as an experimental approach for the treatment of disorders of consciousness (DOC), but in subjects with TBI therapeutic effects on DOC have also been variously documented. Beneficial effects have been reported in subjects with cognitive/emotional disturbances and auditory dysfunction (tinnitus and hallucinations), although the results are somewhat conflicting. rTMS applied over the left prefrontal cortex may relieve, at least transiently, post-traumatic headache. Isolated rTMS studies have been performed in TBI patients with motor impairment, chronic dizziness or pain. Especially whether provided in combination, rTMS and neurorehabilitation may be synergistic in the potential to translate experimental findings in the clinical practice. In order to reach definitive conclusions, well-designed randomized controlled studies with larger patient samples, improved design and optimized rTMS setup, are warranted to verify and corroborate the initial promising findings.
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http://dx.doi.org/10.1016/j.brainresbull.2020.03.016DOI Listing
June 2020

Effects of repetitive transcranial magnetic stimulation in subjects with sleep disorders.

Sleep Med 2020 07 19;71:113-121. Epub 2020 Feb 19.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

In this review, we aimed at identifying the studies that have employed repetitive transcranial magnetic stimulation (rTMS) in patients with sleep disorders. Low-frequency (LF) rTMS stimulating the right dorsolateral prefrontal cortex (DLPFC) or the posterior parietal cortex (PPC) was found to be effective to reduce cortical hyperexcitability and improve the sleep quality in subjects with chronic primary insomnia (PI). Both high-frequency (HF) and LF rTMS applied over the primary motor cortex or the supplementary motor cortex seem to have transient beneficial effects in patients with restless legs syndrome (RLS). Stimulation of upper airway muscles during sleep by isolated TMS and by rTMS twitch can improve airflow dynamics in obstructive sleep apnea syndrome (OSAS) patients without arousal. A single case report study indicates that HF rTMS over the left DLPFC might represent an alternative choice for symptom control in narcoleptic patients with cataplexy, and a pilot study also raises the possibility of therapeutic benefits from rTMS in patients with sleep bruxism. rTMS may also exert intrinsic effects on hypersomnia in depressed adolescents. In conclusion, rTMS may contribute to the development of new non-pharmacological therapeutic options for several sleep disorders. rTMS might be useful as therapeutical tool in particular in patients with PI, RLS, OSAS and narcolepsy, while its effect in other sleep disorders (ie, parasomnias) has not yet been explored. rTMS integrated with clinical, sleep-related, and neuroimaging data may represent an effective tool in modulating cortical excitability and inducing short-term synaptic plasticity. Further studies with larger patient samples, repeated sessions, an optimized rTMS setup, and clinical follow-up warranted to verify the initial findings, and to expand clinical and research interest towards neuromodulation in the different sleep disorders.
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http://dx.doi.org/10.1016/j.sleep.2020.01.028DOI Listing
July 2020

Disinhibition of sensory cortex in patients with amyotrophic lateral sclerosis.

Neurosci Lett 2020 03 22;722:134860. Epub 2020 Feb 22.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

In patients with amyotrophic lateral sclerosis (ALS) a motor cortical hyperexcitability has been reported in transcranial magnetic stimulation studies, but little is known about the neuronal excitability in other cortical areas. The aim of the present study was the functional evaluation of the sensory cortex in subjects with ALS by assessing the high-frequency somatosensory evoked potentials (HF-SEP). No significant HF-SEP abnormalities were observed in ALS patients with disease duration of <2 years, while the patients with a disease duration of>2 years we found a large amplitude reduction of post-synaptic HF-SEP burst. Since post-synaptic burst of HF-SEP is thought to reflect the activity of cortical inhibitory interneurons, our findings provide further evidence that disinhibition is a primary characteristic of ALS that also involves the somatosensory cortex.
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http://dx.doi.org/10.1016/j.neulet.2020.134860DOI Listing
March 2020

Contribution of transcranial magnetic stimulation in restless legs syndrome: pathophysiological insights and therapeutical approaches.

Sleep Med 2020 07 24;71:124-134. Epub 2019 Dec 24.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

Transcranial magnetic stimulation (TMS) may offer a reliable means to characterize significant pathophysiologic and neurochemical aspects of restless legs syndrome (RLS). Namely, TMS has revealed specific patterns of changes in cortical excitability and plasticity, in particular dysfunctional inhibitory mechanisms and sensorimotor integration, which are thought to be part of the pathophysiological mechanisms of RLS rather than reflect a non-specific consequence of sleep architecture alteration. If delivered repetitively, TMS is able to transiently modulate the neural activity of the stimulated and connected areas. Some studies have begun to therapeutically use repetitive TMS (rTMS) to improve sensory and motor disturbances in RLS. High-frequency rTMS applied over the primary motor cortex or the supplementary motor cortex, as well as low-frequency rTMS over the primary somatosensory cortex, seem to have transient beneficial effects. However, further studies with larger patient samples, repeated sessions, an optimized rTMS setup, and clinical follow-up are needed in order to corroborate preliminary results. Thus, we performed a systematic search of all the studies that have used TMS and rTMS techniques in patients with RLS.
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http://dx.doi.org/10.1016/j.sleep.2019.12.009DOI Listing
July 2020

Facilitation of Auditory Comprehension After Theta Burst Stimulation of Wernicke's Area in Stroke Patients: A Pilot Study.

Front Neurol 2019 8;10:1319. Epub 2020 Jan 8.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.

Single-pulse transcranial magnetic stimulation (TMS) and high-frequency repetitive TMS (rTMS) over Wernicke's area were found to facilitate language functions in right-handed healthy subjects. We aimed at investigating the effects of excitatory rTMS, given as intermittent theta burst stimulation (iTBS) over left Wernicke's area, on auditory comprehension in patients suffering from fluent aphasia after stroke of the left temporal lobe. We studied 13 patients with chronic fluent aphasia after an ischemic stroke involving Wernicke's area. iTBS was applied in random order to Wernicke's area, the right-hemisphere homologous of Wernicke's area, and the primary visual cortex. Auditory comprehension was blind assessed using the Token test before (T0), 5 (T1), and 40 min (T2) after a single session of iTBS. At the first evaluation (T1) after iTBS on left Wernike's area, but not on the contralateral homologous area nor on the primary visual cortex, the scores on the Token test were significantly increased. No significant effects were observed at T2. We demonstrated that a single session of excitatory iTBS over Wernicke's area was safe and led to a transient facilitation of auditory comprehension in chronic stroke patients with lesions in the same area. Further studies are needed to establish whether TBS-induced modulation can be enhanced and transformed into longer-lasting effects by means of repeated TBS sessions and by combining TBS with speech and language therapy.
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http://dx.doi.org/10.3389/fneur.2019.01319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960103PMC
January 2020

Transcranial magnetic stimulation and bladder function: A systematic review.

Clin Neurophysiol 2019 11 3;130(11):2032-2037. Epub 2019 Sep 3.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

Objective: We aimed at assessing the usefulness of motor evoked potentials (MEPs) for exploring the integrity of striated sphincters and pelvic floor motor innervation in normal subjects and of repetitive transcranial magnetic stimulation TMS (rTMS) in patients with neurogenic bladder dysfunction.

Methods: A systematic literature search was conducted using PubMed and Embase.

Results: We identified, reviewed and discussed 11 articles matching the inclusion criteria.

Conclusions: The assessment of MEPs could represent a useful tool in the investigation of patients with urologic disorders. High frequency rTMS can improve detrusor contraction and/or urethral sphincter relaxation in patients with multiple sclerosis and bladder dysfunction. Low frequency (LF) rTMS seems to be an effective treatment of neurogenic lower urinary tract dysfunctions in subjects with Parkinson's disease and possibly other neurodegenerative disorders. Furthermore, rTMS might have the potential to restore bladder and bowel sphincter function after incomplete spinal cord injury. LF rTMS could also relieve some symptoms of bladder pain syndrome and chronic pelvic pain.

Significance: The clinical applicability of MEPs appears to be questionable, since a poor reproducibility was detected for all pelvic floor muscles. The use of rTMS in this field is emerging and the results of a few preliminary studies should be replicated in controlled, randomized studies with larger sample sizes.
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http://dx.doi.org/10.1016/j.clinph.2019.08.020DOI Listing
November 2019

Cholinergic transmission is impaired in patients with idiopathic normal-pressure hydrocephalus: a TMS study.

J Neural Transm (Vienna) 2019 08 21;126(8):1073-1080. Epub 2019 Jun 21.

Department of Psychology, University of Akureyri, Akureyri, Iceland.

The pathophysiological mechanisms of cognitive and gait disturbances in subjects with normal-pressure hydrocephalus (NPH) are still unclear. Cholinergic and other neurotransmitter abnormalities have been reported in animal models of NPH. The objective of this study was to evaluate the short latency afferent inhibition (SAI), a transcranial magnetic stimulation protocol which gives the possibility to test an inhibitory cholinergic circuit in the human brain, in subjects with idiopathic NPH (iNPH). We applied SAI technique in twenty iNPH patients before ventricular shunt surgery. Besides SAI, also the resting motor threshold and the short intracortical inhibition to paired stimulation were assessed. A significant reduction of the SAI (p = 0.016), associated with a less pronounced decrease of the resting motor threshold and the short latency intracortical inhibition to paired stimulation, were observed in patients with iNPH at baseline evaluation. We also found significant (p < 0.001) correlations between SAI values and the gait function tests, as well as between SAI and the neuropsychological tests. These findings suggest that the impairment of cholinergic neurons markedly contributes to cognitive decline and gait impairment in subjects with iNPH.
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http://dx.doi.org/10.1007/s00702-019-02036-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6647526PMC
August 2019

Role of human prefrontal cortex in the modulation of conditioned eyeblink responses.

Behav Brain Res 2019 11 15;374:112027. Epub 2019 Jun 15.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

Classical conditioning of the eyeblink reflex (EBC) is a simple form of associative motor learning. EBC is heavily dependent on cerebellar function, but experimental studies also suggest that the prefrontal cortex (PFC) orchestrates a neuronal network which interacts with the cerebellum to mediate the conditioned eyeblink responses (CR). To further investigate the role of PFC for EBC in humans, we aimed in this study at assessing whether acquisition of CR can be modulated by focal repetitive transcranial magnetic stimulation (rTMS) given as theta burst stimulation (TBS) over the dorsolateral PFC (DLPFC). A standard delay conditioning paradigm with a 540 ms tone as conditioned stimulus (CS) coterminating with a 100 ms air puff as unconditioned stimulus (US) was used in a total of 60 healthy subjects (35 female, 25 male, mean age 28.4 ± 2.4 years). One hundred paired CS-US trials and 30 extinction CS alone trials were given. TBS was applied over the DLPFC ipsilaterally to the US during the acquisition phase. Subjects were randomly assigned to three groups (n = 20) using excitatory intermittent TBS (iTBS), inhibitory continuous TBS (cTBS) or sham stimulation. CR acquisition was significantly enhanced by iTBS (mean total CR incidence 63.1 ± 6.5%) and significantly reduced by cTBS (13 ± 2%) compared to sham stimulation (25.1 ± 6.7%). We provide thus physiological evidence that the acquisition of this type of associative learning is critically modulated by PFC activity in humans.
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http://dx.doi.org/10.1016/j.bbr.2019.112027DOI Listing
November 2019

Adult-Onset Gilles de la Tourette Syndrome: Psychogenic or Organic? The Challenge of Abnormal Neurophysiological Findings.

Front Neurol 2019 3;10:461. Epub 2019 May 3.

Department of Neurology, State Hospital Hochzirl, Zirl, Austria.

Gilles de la Tourette syndrome (GTS) is characterized by multiple motor and vocal tics. Adult-onset cases are rare and may be due to "reactivation" of childhood tics, or secondary to psychiatric or genetic diseases, or due to central nervous system lesions of different etiologies. Late-onset psychogenic motor/vocal tics resembling GTS have been described. Neurophysiology may serve to differentiate organic from functional GTS. Altered blink reflex pre-pulse inhibition (BR-PPI), blink reflex excitability recovery (BR-ERC), and short-interval intracortical inhibition (SICI) have been described in GTS. We report a 48-years-old male, who developed numerous motor/vocal tics 2 months after sustaining non-commotional craniofacial trauma in a car accident. Both his father and brother had died earlier in car crashes. He presented with blepharospasm-like forced lid closure, forceful lip pursing, noisy suction movements, and deep moaning sounds, occurring in variable combinations, without warning symptoms or internal "urge." Tics showed low distractibility and these increased with attention. Standard magnetic resonance imaging, electroencephalography, and evoked potentials were unremarkable. Neuropsychology diagnosed moderately impaired intellect, attention, and executive functions. Psychiatric assessment revealed somatization disorder and generalized anxiety. BR-PPI was unremarkable, while BR-ERC was enhanced, even showing facilitation at short intervals. SICI was markedly reduced at 1 and 3 ms and intracortical facilitation (ICF) was enhanced at 10 ms. The patient fulfilled Fahn and Williams' diagnostic criteria for a psychogenic movement disorder. Neurophysiology, however, documented hyperexcitability of motor cortex and brainstem. We suggest that-similar to what has been reported in psychogenic dystonia-a pre-existing predisposition may have led to the functional hyperkinetic disorder in response to severe psychic stress.
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http://dx.doi.org/10.3389/fneur.2019.00461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6509948PMC
May 2019

Effects of Repetitive Transcranial Magnetic Stimulation over Prefrontal Cortex on Attention in Psychiatric Disorders: A Systematic Review.

J Clin Med 2019 Mar 27;8(4). Epub 2019 Mar 27.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, 5020 Salzburg, Austria.

Repetitive transcranial magnetic stimulation (rTMS) may be effective for enhancing cognitive functioning. In this review, we aimed to systematically evaluate the effects of rTMS on attention in psychiatric diseases. In particular, we searched PubMed and Embase to examine the effectiveness of rTMS administered to the dorsolateral prefrontal cortex (DLPFC) on this specific cognitive domain. The search identified 24 articles, 21 of which met inclusion and exclusion criteria. Among them, nine were conducted in patients with depression, four in patients with schizophrenia, three in patients with autism spectrum disorder (ASD), two in patients with attention deficit hyperactivity disorder, one each in patients with Alzheimer's disease and in patients with alcohol or methamphetamine addiction. No evidence for cognitive adverse effects was found in all the included rTMS studies. Several studies showed a significant improvement of attentional function in patients with depression and schizophrenia. The beneficial effects on attention and other executive functions suggest that rTMS has the potential to target core features of ASD. rTMS may influence the attentional networks in alcohol-dependent and other addicted patients. We also reviewed and discussed the studies assessing the effects of rTMS on attention in the healthy population. This review suggests that prefrontal rTMS could exert procognitive effects on attention in patients with many psychiatric disorders.
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http://dx.doi.org/10.3390/jcm8040416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6518000PMC
March 2019

Transcranial magnetic stimulation in subjects with phantom pain and non-painful phantom sensations: A systematic review.

Brain Res Bull 2019 05 9;148:1-9. Epub 2019 Mar 9.

Department of Neurology, Christian Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria; Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Germany.

Several studies have applied transcranial magnetic stimulation (TMS) in the attempt to further explore the pathophysiological mechanisms of phantom-limb pain (PLP) and non-painful phantom sensations (PS). We performed a systematic review of available evidence of this emerging technology in this indication. We identified studies which report a reduced intracortical inhibition and increased intracortical facilitation in the hemisphere contralateral to the PLP. TMS mapping revealed a significant lateralization of the center of gravity and an enlargement of the excitable area on the hemisphere contralateral to the amputation. N-Methyl-d-Aspartate-mediated mechanisms influence the changes of intracortical inhibition and facilitation occurring after limb amputation; however, these cortical excitability changes and PLP are independent of each other. TMS can also influence brain function if applied repetitively. A few studies have begun to therapeutically use repetitive TMS (rTMS) to relief PLP and non-painful PS. rTMS of the contralateral parietal cortex lead to a transient reduction in pain intensity. High frequency rTMS applied over the contralateral motor cortex (M1) or low frequency rTMS over the unaffected hemisphere might also induce significant clinical improvement in PLP. On the other hand, serum beta-endorphin increased significantly after real stimulation over contralateral M1. This systematic review illustrates that TMS technique is an emerging tool to gain insights to pathophysiological aspects of pain and non-painful phantom phenomena. Moreover, TMS could support appropriate patient selection for different therapies and may also have therapeutic utility in subjects with PLP or PS, though the evidence is still very preliminary and well-designed studies in larger cohort of patients are warranted.
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http://dx.doi.org/10.1016/j.brainresbull.2019.03.001DOI Listing
May 2019

Modulation of exteroceptive electromyographic responses in defensive peripersonal space.

J Neurophysiol 2019 04 27;121(4):1111-1124. Epub 2019 Feb 27.

Department of Neurology, Hochzirl Hospital, Zirl, Austria.

The cutaneous silent period (CSP) to noxious finger stimulation constitutes a robust spinal inhibitory reflex that protects the hand from injury. In certain conditions, spinal inhibition is interrupted by a brief burst-like electromyographic activity, dividing the CSP into two inhibitory phases (I1 and I2). This excitatory component is termed long-loop reflex (LLR) and is presumed to be transcortical in origin. Efficient defense from environmental threats requires sensorimotor integration between multimodal sensory afferents and planning of defensive movements. In the defensive peripersonal space (DPPS) immediately surrounding the body, we interact with objects and persons with increased alertness. We investigated whether CSP differs when the stimulated hand is in the DPPS of the face compared with a distant position. Furthermore, we investigated the possible role of vision in CSP modulation. Fifteen healthy volunteers underwent CSP testing with the handheld either within 5 cm from the nose (near) or away from the body (far). Recordings were obtained from first dorsal interosseous muscle following index (D2) or little finger (D5) stimulation with varying intensities. A subgroup of subjects underwent CSP recordings in near and far conditions, both with eyes open and with eyes closed. No inhibitory CSP parameter differed between stimulation in near and far conditions. LLRs occurring following D2 stimulation were significantly larger in near than far conditions at all stimulus intensities, irrespective of subjects seeing their hand. Similar to the hand-blink reflex, spinally organized protective reflexes may be modulated by corticospinal facilitatory input when the hand enters the DPPS of the face. NEW & NOTEWORTHY The present findings demonstrate for the first time that a spinally organized protective reflex, the cutaneous silent period (CSP), may be modulated by top-down corticospinal facilitatory input when the stimulated hand enters the defensive peripersonal space (DPPS) of the face. In particular, the cortically mediated excitatory long-loop reflex, which may interrupt the CSP, is facilitated when the stimulated hand is in the DPPS, irrespective of visual control over the hand. No spinal inhibitory CSP parameter differs significantly in or outside the DPPS.
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http://dx.doi.org/10.1152/jn.00554.2018DOI Listing
April 2019

Ipsilateral motor evoked potentials in a patient with unihemispheric cortical atrophy due to Rasmussen encephalitis.

Neural Regen Res 2019 Jun;14(6):1025-1028

Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy.

The role of the ipsilaterally descending motor pathways in the recovery mechanisms after unilateral hemispheric damage is still poorly understood. Motor output reorganization was investigated in a 56-year-old male patient with acquired unilateral hemispheric atrophy due to Rasmussen encephalitis. In particular, the ipsilateral corticospinal pathways were explored using focal transcranial magnetic stimulation. In the first dorsal interosseous and wrist extensors muscles, the median amplitudes of the ipsilateral motor evoked potentials induced by transcranial magnetic stimulation in the patient were higher than those of 10 age-matched healthy control subjects. In the biceps brachii muscle, the median amplitudes of the ipsilateral motor evoked potentials were the second largest in the patient compared to the controls. This study demonstrated a reinforcement of ipsilateral motor projections from the unaffected motor cortex to the hemiparetic hand in a subject with acquired unihemispheric cortical damage.
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http://dx.doi.org/10.4103/1673-5374.250581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6404490PMC
June 2019

Male Slings for Postprostatectomy Incontinence: A Systematic Review and Meta-analysis.

Eur Urol Focus 2020 05 2;6(3):575-592. Epub 2019 Feb 2.

Department of Urology, Medical University of Graz, Graz, Austria. Electronic address:

Context: Male slings are recommended by the European Association of Urology guideline for the treatment of mild to moderate postprostatectomy incontinence. However, none of them has been proved to be superior to the others, and there are no defined guidelines to preference of a given sling model.

Objective: To evaluate and compare the efficacy and safety of the different types of male slings in the treatment of postprostatectomy incontinence.

Evidence Acquisition: This systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. A systematic literature search in the databases of PubMed, Embase, and Cochrane using the keywords "incontinence," "prostatectomy," and "male sling/system" was conducted in June 2018. Studies in English with at least 15 patients and a minimum follow-up of 12 mo were included. As the primary endpoint, we assessed the cure rate of the different sling types. As secondary endpoints, we assessed the improvement rate, subjective cure rate, overall complication rate, explantation rate, risk factors for failure, and effect on patients' quality of life.

Evidence Synthesis: The literature search identified 833 articles. A total of 64 studies with 72 patient cohorts were eligible for inclusion. Fixed slings were implanted in 55 (76.4%) of the patient cohorts. The objective cure rate varies between 8.3% and 87% (pooled estimate 0.50, 95% confidence interval [CI] 0.45-0.56, I=82%). Subjective cure was achieved in 33-94.4%. Adjustable slings showed objective cure rates between 17% and 92% (pooled estimate 0.61, 95% CI 0.51-0.71, I=88%). The subjective cure rate varies between 28% and 100%. In both types of slings, pain was the most common complication, but chronic painful conditions were really rare (1.3% in fixed slings and 1.5% in adjustable slings). The most common complication after pain was urinary retention in fixed slings, and infection and consequential explantation in adjustable slings.

Conclusions: Both fixed and adjustable slings are beneficial for the treatment of postprostatectomy incontinence. Although adjustable slings might lead to higher objective cure rates, they might be associated with higher complication and explantation rates. However, at present, due to significant heterogeneity of the data, this cannot be said with certainty. More randomized controlled trials with long-term follow-up and the same definition for continence are needed.

Patient Summary: Fixed and adjustable slings are effective treatment options in mild to moderate postprostatectomy incontinence.
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http://dx.doi.org/10.1016/j.euf.2019.01.008DOI Listing
May 2020

Spinal cord involvement in Lewy body-related α-synucleinopathies.

J Spinal Cord Med 2020 11 8;43(6):832-845. Epub 2019 Jan 8.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.

Lewy body (LB)-related α-synucleinopathy (LBAS) is the neuropathological hallmark of several neurodegenerative diseases such as Parkinson disease (PD), but it is also found in neurologically asymptomatic subjects. An abnormal accumulation of α-synuclein has been reported also in the spinal cord, but extent and significance of the spinal cord involvement are still poorly defined. We aimed to review the studies addressing the spinal cord involvement of LBAS in healthy subjects and in patients with PD or other neurodegenerative diseases. A MEDLINE search was performed using following terms: "spinal cord", " α-synucleinopathy", "α-synuclein", "Lewy body", "Parkinson's disease", "multiple system atrophy", "neurodegenerative disorder". LBAS in the spinal cord is associated with that of the medullary reticular formation and locus ceruleus in the brainstem but not with that in the olfactory bulb and amygdala. The intermediolateral columns of the thoracic and sacral cord are the most frequently and severely affected region of the spinal cord. LBAS occurs in centrally projecting spinal cord neurons integrating pain, in particular from lower body periphery. It also involves the sacral parasympathetic nucleus innervating the smooth muscles of the bladder and distal colon and the Onuf's nucleus innervating the striated sphincters. The spinal cord lesions may thus play a crucial role in the genesis of frequent non-motor symptoms such as pain, urinary symptoms, bowel dysfunction, autonomic failure including orthostatic hypotension and sexual disturbances. Moreover, these may also contribute to the motor symptoms, since α-synuclein inclusions have been observed in the pyramidal tracts of patients with PD and multiple system atrophy. Recognition of this peculiar spinal cord pathology may help in the management of the related symptoms in subjects affected by α-synucleinopathies.
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http://dx.doi.org/10.1080/10790268.2018.1557863DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7808259PMC
November 2020

Pathophysiology of corticobasal degeneration: Insights from neurophysiological studies.

J Clin Neurosci 2019 Feb 13;60:17-23. Epub 2018 Oct 13.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria.

Background: Several studies have applied electrophysiological techniques to physiologically characterize corticobasal degeneration (CBD).

Methods: We performed a systematic literature search of these studies and reviewed all 25 identified articles.

Results: Conventional electroencephalography (EEG) is usually normal even in the late stages of disease. Quantitative EEG (qEEG) with spectral analysis revealed mainly lateralized abnormalities, such as an increase of slow wave activity and occasionally the occurrence of sharp waves, and a significant increase of coherence between left parietal-right premotor areas. CBD patients generally have long latency reflexes (LLR) with shorter latencies than in the classic cortical reflex myoclonus observed in progressive myoclonic epilepsy. The somatosensory evoked potentials (SEPs) showed reduced amplitude of the N20-P25 component. These abnormalities may reflect dysfunction of sensory projections to the motor cortex, while the localized parietal cortical damage is thought to be a pivotal factor for the absence of giant SEPs in these patients. Transcranial magnetic stimulation (TMS) revealed asymmetric intracortical disinhibition and asymmetric maps organization; an impaired transcallosal pathways function correlates with the atrophy of the corpus callosum. These findings suggest a pathologic hyperexcitability of the motor cortex, due to a loss of inhibitory input from the sensory cortex.

Conclusions: Neurophysiological techniques, in combination with neuroimaging studies, may shed light on the pathophysiological mechanisms of CBD. A better understanding of the disease processes may help clinicians to make a more accurate and early diagnosis. TMS, SEP, LLR, and co-evaluation of EEG and EMG can aid the in differentiation between CBD and other parkinsonism syndromes.
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http://dx.doi.org/10.1016/j.jocn.2018.10.027DOI Listing
February 2019

Usefulness of EEG Techniques in Distinguishing Frontotemporal Dementia from Alzheimer's Disease and Other Dementias.

Dis Markers 2018 3;2018:6581490. Epub 2018 Sep 3.

Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.

The clinical distinction of frontotemporal dementia (FTD) and Alzheimer's disease (AD) may be difficult. In this narrative review we summarize and discuss the most relevant electroencephalography (EEG) studies which have been applied to demented patients with the aim of distinguishing the various types of cognitive impairment. EEG studies revealed that patients at an early stage of FTD or AD displayed different patterns in the cortical localization of oscillatory activity across different frequency bands and in functional connectivity. Both classical EEG spectral analysis and EEG topography analysis are able to differentiate the different dementias at group level. The combination of standardized low-resolution brain electromagnetic tomography (sLORETA) and power parameters seems to improve the sensitivity, but spectral and connectivity biomarkers able to differentiate single patients have not yet been identified. The promising EEG findings should be replicated in larger studies, but could represent an additional useful, noninvasive, and reproducible diagnostic tool for clinical practice.
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http://dx.doi.org/10.1155/2018/6581490DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140274PMC
January 2019