Progressive Tetraparesis in a 57-Year-Old Man With Congenital Absence of an Anterior Spinal Artery: A Case of Anterior Spinal Cord Infarction

A 57-year-old man presented with sudden neck pain radiating down his arms. This pain progressed to bilateral upper and subsequently lower extremity weakness and numbness. His vitals were notable for systolic blood pressures lower than his baseline (down to 90 mm Hg). The patient's neurological examination as well as magnetic resonance imaging of the cervical and thoracic spine localized to a lesion in the anterior spinal cord. The differential diagnosis for such an acute presentation included stroke, demyelination, intramedullary neoplasm, infection, metabolic myelopathy, and a dural arteriovenous fistula. Further imaging with angiography demonstrated that our patient lacked an anterior spinal artery. In its place, collateral flow from cervical artery branches provided sustenance to the anterior spinal cord. In the setting of hemodynamic instability, this variant anatomy likely predisposed the patient to ischemia, leading to the classic presentation of anterior cord syndrome.

Focal Unilateral Palatal Myoclonus Causing Objective Clicking Tinnitus without Uvula Elevation Diagnosed by Concurrent Auscultation

Palatal myoclonus generally entails a visible elevation of the palate and uvula and may be accompanied by myoclonus of other oropharyngeal muscles. A 55-year-old man presented with left ear clicking and hyperacusis. Examination showed arrhythmic left lateral soft palate contraction in the tensor veli palatini region without elevation of the uvula, which correlated with an audible click by auscultation with a stethoscope over the left ear. This is a rare case of focal, unilateral palatal myoclonus without visual uvula elevation with concurrent auscultation, demonstrating the importance of careful examination to detect focal myoclonic contractions.

New Onset Seizure Disorder Following Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is an effective treatment for many psychiatric illnesses including refractory depression, catatonia, bipolar disorder, and schizophrenia, along with neuropsychiatric diseases such as dementia and Parkinson's disease. The emergence of a seizure disorder after the initiation of ECT is a rare but severe occurrence. It can become challenging for clinicians to determine whether ECT should be continued. We present a case of a 73-year-old female with schizoaffective disorder who received a total of 173 ECT treatments over the course of five years for breakthrough psychosis due to medication nonadherence. After five years of treatment, she experienced her first episode of tonic-clonic seizure activity. We review the current evidence and discuss factors that should be considered when treating such an individual.

Abstract WP217: Sex Differences in Coagulation After Stroke: Factor XI Levels Drop After Acute Ischemic Stroke

Introduction: Sex differences in coagulation have been well documented, but it is unknown if post-stroke coagulation factor levels differ by sex. High levels of Factor XI (FXI) and Factor XII (FXII) have been associated with increased incidence of acute ischemic stroke (AIS), especially in women.

Hypothesis: This study investigates the hypothesis that levels of FXI, FXII and Plasminogen Activating Inhibitor (PAI1) are different after AIS in men and women.

Methods: This was a retrospective study using a biomarker database of patients who presented to the emergency department with stroke. Sample collection occurred 24 hours after AIS onset. Plasma levels of FXI, FXII and PAI1 were assessed with ELISA in a population of 73 patients with no prior history of coagulation disorders, including 29 controls and 44 AIS patients confirmed by MRI, mean age = 68.7+/- 15.1, and 47% female. Log transformation was done before fitting the model. ANOVA was used to investigate the relationship between factor levels in sex and stroke. Tukey-Kramer multiple comparison tests were used for paired group comparisons.

Results: FXI levels were significantly higher in control subjects compared to AIS (p-value=0.007). FXI levels were also higher in females than in males, nearing statistical significance (p-value=0.053). PAI1 and FXII levels were not statistically different in men vs. women, or in control vs. AIS patients. Female controls had higher FXI levels than male AIS patients (0.487, 95% CI 0.085-0.889).

Conclusion: Stroke patients were found to have significantly lower levels of FXI compared to controls. This demonstrates that the pathological process of AIS may result in depletion of circulating plasma FXI at 24 hours after stroke onset. Overall, in stroke and control patients, there was a trend for females to have higher levels of FXI than men. No significant sex or stroke differences were found in FXII or PAI1 levels, likely due to sample size. Additional samples are being evaluated to determine if this stroke-induced decrease in FXI levels is associated with functional outcomes.

Resting state connectivity immediately following learning correlates with subsequent sleep-dependent enhancement of motor task performance

There is ongoing debate concerning the functions of resting-state brain activity. Prior work demonstrates that memory encoding enhances subsequent resting-state functional connectivity within task-relevant networks and that these changes predict better recognition. Here, we used functional connectivity MRI (fcMRI) to examine whether task-induced changes in resting-state connectivity correlate with performance improvement after sleep. In two separate sessions, resting-state scans were acquired before and after participants performed a motor task. In one session participants trained on the motor sequence task (MST), a well-established probe of sleep-dependent memory consolidation, and were tested the next day, after a night of sleep. In the other session they performed a motor control task (MCT) that minimized learning. In an accompanying behavioral control study, participants trained on the MST and were tested after either a night of sleep or an equivalent interval of daytime wake. Both the fcMRI and the sleep control groups showed significant improvement of MST performance, while the wake control group did not. In the fcMRI group, increased connectivity in bilateral motor cortex following MST training correlated with this next-day improvement. This increased connectivity did not appear to reflect initial learning since it did not correlate with learning during training and was not greater after MST training than MCT performance. Instead, we hypothesize that this increased connectivity processed the new memories for sleep-dependent consolidation. Our findings demonstrate that physiological processes immediately after learning correlate with sleep-dependent performance improvement and suggest that the wakeful resting brain prepares memories of recent experiences for later consolidation during sleep.