Publications by authors named "Keerthana Nalamada"

7 Publications

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Does alleviate tinnitus? A review of the current literature.

Laryngoscope Investig Otolaryngol 2020 Dec 30;5(6):1147-1155. Epub 2020 Oct 30.

Division of Otolaryngology - Head and Neck Surgery, Department of Surgery Yale University School of Medicine New Haven Connecticut USA.

Objectives: Endocannabinoid pathways have been proposed to affect the underlying pathophysiology of tinnitus. The aim of this study is to evaluate the scope and findings of existing literature on the relationship between and cannabinoid pathways and tinnitus.

Methods: We conducted a review of animal, clinical and survey studies investigating the relationship between the use of -derived agents and tinnitus. Using pertinent keywords and MeSH terms on PubMed, relevant studies were identified, yielding four animal studies, two large cross-sectional survey studies, one clinical cross-over study, and one case report.

Results: Animal studies revealed that cannabinoid receptor expression in the cochlear nucleus varied with tinnitus symptomatology and the use of cannabinoid agents either increased or had no effect on tinnitus-related behavior. Survey studies yielded conflicting results between use and tinnitus in the general population. Clinical data is largely lacking, although a small cohort study showed a dose-dependent relationship between tetrahydrocannabinol consumption and frequency of tinnitus episodes in patients receiving treatment for cancer.

Conclusion: While animal studies have revealed that cannabinoid receptors likely have a role in modulating auditory signaling, there is no compelling data either from animal or human studies for the use of cannabinoids to alleviate tinnitus. Further research is necessary to elucidate their precise role to guide development of therapeutic interventions.

Level Of Evidence: NA.
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http://dx.doi.org/10.1002/lio2.479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7752070PMC
December 2020

Structural and functional brain changes in hepatic and neurological Wilson disease.

Brain Imaging Behav 2020 Nov 26. Epub 2020 Nov 26.

Departments of Medicine and Surgery, Sections of Digestive Diseases and Transplant and Immunology, Yale University School of Medicine, New Haven, CT, USA.

Wilson disease (WD) can manifest with hepatic or neuropsychiatric symptoms. Our understanding of the in vivo brain changes in WD, particularly in the hepatic phenotype, is limited. Thirty subjects with WD and 30 age- and gender-matched controls participated. WD group underwent neuropsychiatric assessment. Unified WD Rating Scale neurological exam scores were used to determine neurological (WDN, score > 0) and hepatic-only (WDH, score 0) subgroups. All subjects underwent 3 Tesla anatomical and resting-state functional MRI. Diffusion tensor imaging (DTI) and susceptibility-weighted imaging (SWI) were performed only in the WD group. Volumetric, DTI, and functional connectivity analyses were performed to determine between-group differences. WDN and WDH groups were matched in demographic and psychiatric profiles. The entire WD group compared to controls showed significant thinning in the bilateral superior frontal cortex. The WDN group compared to control and WDH groups showed prominent structural brain changes including significant striatal and thalamic atrophy, more subcortical hypointense lesions on SWI, and diminished white matter integrity in the bilateral anterior corona radiata and corpus callosum. However, the WDH group also showed significant white matter volume loss compared to controls. The functional connectivity between the frontostriatal nodes was significantly reduced in the WDN group, whereas that of the hippocampus was significantly increased in the WDH group compared to controls. In summary, structural and functional brain changes were present even in neurologically non-manifesting WD patients in this cross-sectional study. Longitudinal brain MRI scans may be useful as biomarkers for prognostication and optimization of treatment strategies in WD.
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http://dx.doi.org/10.1007/s11682-020-00420-5DOI Listing
November 2020

Insula as the Interface Between Body Awareness and Movement: A Neurofeedback-Guided Kinesthetic Motor Imagery Study in Parkinson's Disease.

Front Hum Neurosci 2018 7;12:496. Epub 2018 Dec 7.

Department of Radiology & Biomedical Imaging, Yale School of Medicine, Yale University, New Haven, CT, United States.

Intentional movement is an internally driven process that requires the integration of motivational and sensory cues with motor preparedness. In addition to the motor cortical-basal ganglia circuits, the limbic circuits are also involved in the integration of these cues. Individuals with Parkinson's disease (PD) have a particular difficulty with internally generating intentional movements and maintaining the speed, size, and vigor of movements. This difficulty improves when they are provided with external cues suggesting that there is a problem with the internal motivation of movement in PD. The prevailing view attributes this difficulty in PD to the dysfunction of motor cortical-basal ganglia circuits. First, we argue that the standard cortical-basal ganglia circuit model of motor dysfunction in PD needs to be expanded to include the insula which is a major hub within the limbic circuits. We propose a neural circuit model highlighting the interaction between the insula and dorsomedial frontal cortex which is involved in generating intentional movements. The insula processes a wide range of sensory signals arising from the body and integrates them with the emotional and motivational context. In doing so, it provides the impetus to the dorsomedial frontal cortex to initiate and sustain movement. Second, we present the results of our proof-of-concept experiment demonstrating that the functional connectivity of the insula-dorsomedial frontal cortex circuit can be enhanced with neurofeedback-guided kinesthetic motor imagery using functional magnetic resonance imaging in subjects with PD. Specifically, we found that the intensity and quality of body sensations evoked during motor imagery and the emotional and motivational context of motor imagery determined the direction (i.e., negative or positive) of the insula-dorsomedial frontal cortex functional connectivity. After 10-12 neurofeedback sessions and "off-line" practice of the successful motor imagery strategies all subjects showed a significant increase in the insula-dorsomedial frontal cortex functional connectivity. Finally, we discuss the implications of these results regarding motor function in patients with PD and propose suggestions for future studies.
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http://dx.doi.org/10.3389/fnhum.2018.00496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292989PMC
December 2018

Insula as the Interface Between Body Awareness and Movement: A Neurofeedback-Guided Kinesthetic Motor Imagery Study in Parkinson's Disease.

Front Hum Neurosci 2018 7;12:496. Epub 2018 Dec 7.

Department of Radiology & Biomedical Imaging, Yale School of Medicine, Yale University, New Haven, CT, United States.

Intentional movement is an internally driven process that requires the integration of motivational and sensory cues with motor preparedness. In addition to the motor cortical-basal ganglia circuits, the limbic circuits are also involved in the integration of these cues. Individuals with Parkinson's disease (PD) have a particular difficulty with internally generating intentional movements and maintaining the speed, size, and vigor of movements. This difficulty improves when they are provided with external cues suggesting that there is a problem with the internal motivation of movement in PD. The prevailing view attributes this difficulty in PD to the dysfunction of motor cortical-basal ganglia circuits. First, we argue that the standard cortical-basal ganglia circuit model of motor dysfunction in PD needs to be expanded to include the insula which is a major hub within the limbic circuits. We propose a neural circuit model highlighting the interaction between the insula and dorsomedial frontal cortex which is involved in generating intentional movements. The insula processes a wide range of sensory signals arising from the body and integrates them with the emotional and motivational context. In doing so, it provides the impetus to the dorsomedial frontal cortex to initiate and sustain movement. Second, we present the results of our proof-of-concept experiment demonstrating that the functional connectivity of the insula-dorsomedial frontal cortex circuit can be enhanced with neurofeedback-guided kinesthetic motor imagery using functional magnetic resonance imaging in subjects with PD. Specifically, we found that the intensity and quality of body sensations evoked during motor imagery and the emotional and motivational context of motor imagery determined the direction (i.e., negative or positive) of the insula-dorsomedial frontal cortex functional connectivity. After 10-12 neurofeedback sessions and "off-line" practice of the successful motor imagery strategies all subjects showed a significant increase in the insula-dorsomedial frontal cortex functional connectivity. Finally, we discuss the implications of these results regarding motor function in patients with PD and propose suggestions for future studies.
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http://dx.doi.org/10.3389/fnhum.2018.00496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292989PMC
December 2018

Demoralization in Parkinson disease.

Neurology 2018 05 4;90(18):e1613-e1617. Epub 2018 Apr 4.

From the Department of Neurology (B.B.K., C.A.C., D.R.S., F.H.K., B.S., D.D., K.N., K.S.P., V.M.K., A.S.P., E.D.L.), Center for Neuroepidemiology and Clinical Neurologic Research (B.B.K., E.D.L.), Department of Psychiatry (J.M.d.F.), Yale University; and Department of Chronic Disease Epidemiology (E.D.L.), Yale School of Public Health, Yale University, New Haven, CT.

Objective: To determine the prevalence and associated features of demoralization in Parkinson disease (PD).

Methods: Participants with PD and controls were prospectively recruited from outpatient movement disorder clinics and the community. Demoralization was defined as scoring positively on the Diagnostic Criteria for Psychosomatic Research, Demoralization questionnaire or Kissane Demoralization Scale score ≥24. Depression was defined as Patient Health Questionnaire-9 score ≥10. Forward stepwise logistic regression was used to determine the odds of having demoralization in the overall, control, and PD cohorts.

Results: Demoralization occurred in 18.1% of 94 participants with PD and 8.1% of 86 control participants ( = 0.05). These 2 groups were otherwise comparable in age, sex, education, economics, race, and marital status. Although demoralization was highly associated with depression, there were individuals with one and not the other. Among participants with PD, 7 of 19 (36.8%) depressed individuals were not demoralized, and 5 of 17 (29.4%) demoralized individuals were not depressed. In the overall cohort, having PD (odds ratio 2.60, 95% confidence interval 1.00-6.80, = 0.051) was associated with demoralization, along with younger age and not currently being married. In the PD cohort, younger age and Unified Parkinson's Disease Rating Scale, part III score (per score 1) were associated with demoralization (odds ratio 1.06, 95% confidence interval 1.01-1.12, = 0.02).

Conclusions: Demoralization is common in PD and is associated with motor dysfunction. In demoralization, there is a prominent inability to cope, making it somewhat distinct from depression. Treatment approaches are also different, making it important to identify demoralization in patients with PD.
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http://dx.doi.org/10.1212/WNL.0000000000005425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931805PMC
May 2018

Readability and quality assessment of internet-based patient education materials related to laryngeal cancer.

Head Neck 2016 Apr 22;38(4):601-5. Epub 2015 Jun 22.

Department of Otolaryngology, St George's Hospital, Tooting, London, United Kingdom.

Background: Patients are increasingly using the internet to access health-related information. The purpose of this study was to assess the readability and quality of laryngeal cancer-related websites.

Methods: Patient education materials were identified by performing an internet search using 3 search engines. Readability was assessed using Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level (FKGL), and Gunning Fog Index (GFI). The DISCERN instrument was utilized to assess quality of health information.

Results: A total of 54 websites were included in the analysis. The mean readability scores were as follows: FRES, 48.2 (95% confidence interval [CI] = 44.8-51.6); FKGL, 10.9 (95% CI = 10.3-11.5); and GFI, 13.8 (95% CI = 11.3-16.3). These scores suggest that, on average, online information about patients with laryngeal cancer is written at an advanced level. The mean DISCERN score was 49.8 (95% CI = 45.4-54.2), suggesting that online information is of variable quality.

Conclusion: Our study suggests much of the laryngeal cancer information available online is of suboptimal quality and written at a level too difficult for the average adult to read comfortably.
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http://dx.doi.org/10.1002/hed.23939DOI Listing
April 2016

Anomalous origin of the right vertebral artery from the right common carotid artery associated with an aberrant right subclavian artery.

J Neurointerv Surg 2013 Sep 2;5(5):e34. Epub 2012 Aug 2.

Department of Neurosurgery, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA.

Vertebral artery origin anomalies are typically incidental findings during angiography or post mortem examination. We present two cases of vertebral origin from the right common carotid artery in association with an aberrant right subclavian artery. We also review the embryonic development and the clinical significance of this anomaly.
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http://dx.doi.org/10.1136/neurintsurg-2011-010229DOI Listing
September 2013