Medicine and Health Sciences Commons^™

Degenerative Cervical Myelopathy, Ratko Yurac, José Manuel Matamala, Juan José Zamorano, James S Harrop, Benjamin M Davies, Aria Nouri, Michael G Fehlings

Department of Neurology Faculty Papers

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Its prevalence is increasing as a result of population aging. The diagnosis of DCM is often delayed or overlooked, resulting in secondary neurologic morbidity. The natural course of DCM typically presents as a gradual neurological deterioration, with symptoms ranging from muscle weakness to complete paralysis, with variable degrees of sensory deficits and sphincter dysfunction. Magnetic resonance imaging (MRI) and electrophysiological studies allow the assessment of spinal cord function and its structural damage to determine treatment and clinical outcomes. All patients with signs and symptoms consistent …

Enhanced Co-Registration Methods To Improve Intracranial Electrode Contact Localization., Walter A. Hinds, Amrit Misra, Michael R. Sperling, Ashwini Sharan, Joseph I. Tracy, Karen A. Moxon

Department of Neurology Faculty Papers

Background: Electrode contact locations are important when planning tailored brain surgeries to identify pathological tissue targeted for resection and conversely avoid eloquent tissue. Current methods employ trained experts to use neuroimaging scans that are manually co-registered and localize contacts within ~2 mm. Yet, the state of the art is limited by either the expertise needed for each type of intracranial electrode or the inter-modality co-registration which increases error, reducing accuracy. Patients often have a variety of strips, grids and depths implanted; therefore, it is cumbersome and time-consuming to apply separate localization methods for each type of electrode, requiring expertise across …

Closed-Loop Stimulation Of Temporal Cortex Rescues Functional Networks And Improves Memory., Youssef Ezzyat, Paul A. Wanda, Deborah F. Levy, Allison Kadel, Ada Aka, Isaac Pedisich, Michael R. Sperling, Ashwini Sharan, Bradley C. Lega, Alexis Burks, Robert E. Gross, Cory S. Inman, Barbara C. Jobst, Mark A. Gorenstein, Kathryn A. Davis, Gregory A. Worrell, Michal T. Kucewicz, Joel M. Stein, Richard Gorniak, Sandhitsu R. Das, Daniel S. Rizzuto, Michael J. Kahana

Department of Neurology Faculty Papers

Memory failures are frustrating and often the result of ineffective encoding. One approach to improving memory outcomes is through direct modulation of brain activity with electrical stimulation. Previous efforts, however, have reported inconsistent effects when using open-loop stimulation and often target the hippocampus and medial temporal lobes. Here we use a closed-loop system to monitor and decode neural activity from direct brain recordings in humans. We apply targeted stimulation to lateral temporal cortex and report that this stimulation rescues periods of poor memory encoding. This system also improves later recall, revealing that the lateral temporal cortex is a reliable target …

Widespread Theta Synchrony And High-Frequency Desynchronization Underlies Enhanced Cognition., E. A. Solomon, J. E. Kragel, Michael R. Sperling, Ashwini Sharan, G. Worrell, M. Kucewicz, C. S. Inman, B. Lega, K. A. Davis, J. M. Stein, B. C. Jobst, K. A. Zaghloul, S. A. Sheth, D. S. Rizzuto, M. J. Kahana

Department of Neurology Faculty Papers

The idea that synchronous neural activity underlies cognition has driven an extensive body of research in human and animal neuroscience. Yet, insufficient data on intracranial electrical connectivity has precluded a direct test of this hypothesis in a whole-brain setting. Through the lens of memory encoding and retrieval processes, we construct whole-brain connectivity maps of fast gamma (30-100 Hz) and slow theta (3-8 Hz) spectral neural activity, based on data from 294 neurosurgical patients fitted with indwelling electrodes. Here we report that gamma networks desynchronize and theta networks synchronize during encoding and retrieval. Furthermore, for nearly all brain regions we studied, …

Secondary Hematoma Expansion And Perihemorrhagic Edema After Intracerebral Hemorrhage: From Bench Work To Practical Aspects., Krista Lim-Hing, Fred Rincon

Department of Neurology Faculty Papers

Intracerebral hemorrhages (ICH) represent about 10-15% of all strokes per year in the United States alone. Key variables influencing the long-term outcome after ICH are hematoma size and growth. Although death may occur at the time of the hemorrhage, delayed neurologic deterioration frequently occurs with hematoma growth and neuronal injury of the surrounding tissue. Perihematoma edema has also been implicated as a contributing factor for delayed neurologic deterioration after ICH. Cerebral edema results from both blood-brain barrier disruption and local generation of osmotically active substances. Inflammatory cellular mediators, activation of the complement, by-products of coagulation and hemolysis such as thrombin …

Surgical Outcome In Pet-Positive, Mri-Negative Patients With Temporal Lobe Epilepsy, Carla Lopinto-Khoury, Michael R. Sperling, Christopher Skidmore, Maromi Nei, James Evans, Ashwini Sharan, Scott Mintzer

Department of Neurology Faculty Papers

PURPOSE:

Fluorodeoxyglucose positron emission computed tomography (FDG-PET) hypometabolism is important for surgical planning in patients with temporal lobe epilepsy (TLE), but its significance remains unclear in patients who do not have evidence of mesial temporal sclerosis (MTS) on magnetic resonance imaging (MRI). We examined surgical outcomes in a group of PET-positive, MRI-negative patients and compared them with those of patients with MTS.

METHODS:

We queried the Thomas Jefferson University Surgical Epilepsy Database for patients who underwent anterior temporal lobectomy (ATL) from 1991 to 2009 and who had unilateral temporal PET hypometabolism without an epileptogenic lesion on MRI (PET+/MRI-). We compared …