Publications by authors named "Daniel A Lazar"

3 Publications

  • Page 1 of 1

Isolated superior orbital fissure syndrome resulting from gunshot wound to the head.

Curr Probl Diagn Radiol 2012 Jul-Aug;41(4):112-3

Department of Neurological Surgery, Harborview Medical Center, University of Washington School of Medicine, Seattle, WA, USA.

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http://dx.doi.org/10.1067/j.cpradiol.2011.07.012DOI Listing
September 2012

Superior semicircular canal dehiscence syndrome: Successful treatment with repair of the middle fossa floor: technical case report.

Neurosurgery 2008 Dec;63(6):E1207-8; discussion E1208

Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA.

Objective: Superior semicircular canal dehiscence syndrome has recently been reported as a cause of pressure- or sound-induced oscillopsia (Tullio phenomenon). We report the presentation and successful treatment of 3 patients with superior semicircular dehiscence syndrome by a joint neurosurgical/neuro-otology team.

Clinical Presentation: Patient 1 is a 37-year-old man who presented with complaints of disequilibrium, fullness in the left ear, hearing loss, and oscillopsia when pressure was applied to the left external auditory canal. Patient 2 is a 46-year-old man who presented with complaints of disequilibrium, fullness in the left ear, and blurred vision associated with heavy lifting or straining. On examination, pneumatic otoscopy produced a sense of motion. Patient 3 is a 29-year-old woman who presented with chronic disequilibrium that resulted in frequent falls. She had a positive fistula test on the left, and vertical nystagmus was elicited when pressure was applied to the left ear. In each patient, high-resolution computed tomographic scanning through the temporal bone revealed dehiscence of the superior semicircular canal on the symptomatic side.

Intervention: In all 3 cases, a subtemporal, extradural approach was performed with repair of the middle fossa floor using calcium phosphate BoneSource (Howmedica Leibinger, Inc., Dallas, TX). All patients recovered well, with resolution of their symptoms.

Conclusion: Superior semicircular canal dehiscence syndrome is a cause of disequilibrium associated with sound or pressure stimuli. The workup includes a detailed history, electronystagmography including Valsalva maneuvers, and a high-resolution computed tomographic scan though the temporal bone. An extradural repair of the middle fossa floor with BoneSource can successfully treat this condition.
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http://dx.doi.org/10.1227/01.NEU.0000335179.02759.A8DOI Listing
December 2008

High-resolution magnetic resonance imaging is a noninvasive method of observing injury and recovery in the peripheral nervous system.

Neurosurgery 2003 Jul;53(1):199-203; discussion 203-4

Department of Radiology, University of Washington School of Medicine, Seattle, Washington 98195, USA.

Objective: Noninvasive observation of degenerating and regenerating peripheral nerves could improve the diagnosis and treatment of nerve injuries. We constructed a novel phased-array radiofrequency coil to permit magnetic resonance imaging (MRI) observation of the sciatic nerve and its target muscles in rats after injury.

Methods: Adult male Lewis rats underwent either crushing (n = 18) or cutting and capping (n = 17) of their right sciatic nerves and then underwent serial MRI. Serial gait track analysis was performed to assess behavioral recovery. Animals from both groups were killed at several time points for histological evaluation of the nerves, with axon counting.

Results: Crushed sciatic nerves demonstrated increased T2-weighted signals, followed by signal normalization as axonal regeneration and behavioral recovery occurred. Cut sciatic nerves prevented from regenerating displayed a prolonged phase of increased signal intensity. Acutely denervated muscles exhibited hyperintense T2-weighted signals, which normalized with reinnervation and behavioral recovery. Chronically denervated muscles demonstrated persistently increased T2-weighted signals and atrophy.

Conclusion: In this study, we demonstrated the ability of MRI to noninvasively monitor injury and recovery in the peripheral nervous system, by demonstrating changes in nerve and muscle that correlated with histological and behavioral evidence of axonal degeneration and regeneration. This study demonstrates the potential of MRI to distinguish traumatic peripheral nerve injuries that recover through axonal regeneration (i.e., axonotmetic grade) from those that do not and therefore require surgical repair (i.e., neurotmetic grade). This diagnostic modality could improve treatment by providing earlier and more accurate diagnoses of nerve damage, as well as reducing the need for exploratory surgery.
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http://dx.doi.org/10.1227/01.neu.0000069534.43067.28DOI Listing
July 2003
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