Electrographic Seizures in Patients with Acute Encephalitis.

INTRODUCTION: Clinical seizures and status epilepticus are frequent complications of encephalitis, can lead to depressed level of consciousness, and are associated with poor outcome. We sought to determine the frequency, risk factors, and clinical impact of electrographic seizures detected with continuing electroencephalography (cEEG) in patients with encephalitis and altered level of consciousness. METHODS: We retrospectively identified all patients with presumed or definite viral or autoimmune encephalitis who underwent cEEG monitoring at Henry Ford Hospital from January 2012 to October 2017. Clinical data and cEEG monitoring reports were abstracted and recorded. The primary outcome was electrographic seizures detected by cEEG. RESULTS: Of 1,735 patients who underwent a minimum of 12 h of cEEG monitoring, we identified 54 with a verified discharge diagnosis of encephalitis. Twenty-two of these patients (41%) had electrographic seizures on cEEG. Compared with encephalitis patients without seizures, electrographic seizures were associated with lower serum sodium levels (137 ± 5 vs 141 ± 7, P = 0.027) and more often were on antiepileptic therapy (100% vs 78%, P = 0.033) on the first day of monitoring. Seizures were also associated with a higher frequency of cortical imaging abnormalities (68% vs 28%, P = 0.005), lateralized periodic discharges (LPDs; 50% vs 16%, P = 0.014), delta background frequency (81% vs 45%, P = 0.010), low or suppressed voltage (96% vs 62%, P = 0.005), and focal slowing (86% vs 47%, P = 0.004). There was no association between electrographic seizures and clinical outcome at discharge. CONCLUSION: Electrographic seizures occur in approximately 40% of patients with acute encephalitis. Low serum sodium, cortical imaging abnormalities, and on cEEG LPDs and background abnormalities are associated factors. The lack of association with short-term outcome suggests that with aggressive treatment, the clinical impact of electrographic seizures in encephalitis can be minimized.

Spinal Epidural Venous Plexus Pathology in Hirayama Disease.

Hirayama disease is a rare juvenile amyotrophy that is often misdiagnosed as an unrelated, relentlessly progressive disease. We present the case of an 18-year-old man who presented with weakness and atrophy of the right forearm and hand. Dynamic cervical magnetic resonance imaging was used, revealing the classic findings of epidural venous plexus dilation and anterior displacement of the dural sac. In addition, dilation of the external vertebral venous plexus was visualized. We discuss the clinical utility of dynamic magnetic resonance imaging and the underlying pathophysiology of these findings in Hirayama disease.

The use and yield of continuous EEG in critically ill patients: A comparative study of three centers.

OBJECTIVE: Continuous EEG (cEEG) monitoring of critically ill patients has gained widespread use, but there is substantial reported variability in its use. We analyzed cEEG and antiseizure drug (ASD) usage at three high volume centers. METHODS: We utilized a multicenter cEEG database used daily as a clinical reporting tool in three tertiary care sites (Emory Hospital, Brigham and Women's Hospital and Yale - New Haven Hospital). We compared the cEEG usage patterns, seizure frequency, detection of rhythmic/periodic patterns (RPP), and ASD use between the sites. RESULTS: 5792 cEEG sessions were analyzed. Indication for cEEG monitoring and recording duration were similar between the sites. Seizures detection rate was nearly identical between the three sites, ranging between 12.3% and 13.6%. Median time to first seizure and detection rate of RPPs were similar. There were significant differences in doses of levetiracetam, valproic acid, and lacosamide used between the three sites. CONCLUSIONS: There was remarkable uniformity in seizure detection rates within three high volume centers. In contrast, dose of ASD used frequently differed between the three sites. SIGNIFICANCE: These large volume data are in line with recent guidelines regarding cEEG use. Difference in ASD use suggests discrepancies in how cEEG results influence patient management.

A prospective, masked 18-month minimum follow-up on neurophysiologic changes in persons with spinal stenosis, low back pain, and no symptoms.

OBJECTIVES: To describe neurophysiologic changes over time in persons with and without spinal complaints and to assess whether paraspinal denervation predicts change in stenosis on magnetic resonance imaging (MRI) and clinical course. DESIGN: Prospective, controlled, masked trial. SETTING: University spine program. PARTICIPANTS: Persons aged 55 to 80 years, screened for polyneuropathy and determined on clinical examination to have spinal stenosis, mechanical low back pain, or no spinal symptoms. INTERVENTIONS: A comprehensive codified history was obtained and subjects underwent physical examination, ambulation testing, masked electrodiagnostic testing including paraspinal mapping, and MRI, repeated at greater than 18 months. This study presents detailed technical information and additional analyses not reported previously. MAIN OUTCOME MEASUREMENTS: Change in electrodiagnostic findings. Among persons with clinical stenosis, relationship of change in paraspinal mapping scores to MRI findings and clinical changes. RESULTS: Of 149 initial subjects, 83 (79.3% of eligible subjects) repeated testing at 20 (+/-2 SDs) months. No significant change in limb muscle spontaneous activity or motor unit pathology was noted in any group. In 23 persons with initial diagnosis of stenosis, paraspinal mapping electromyography related to change in diagnosis over time (analysis of variance F = 3.77, P = .037), but not to most initial magnetic resonance imaging measurements or to change in spinal canal diameter. CONCLUSIONS: Clinical spinal stenosis is neurophysiologically stable in most persons. Paraspinal electromyographic changes reflect large changes in clinical course, but neither neurophysiologic nor clinical changes relate to change in spinal geometry over 20 months.

Assessment of the validity of masking in electrodiagnostic research.

OBJECTIVES: Performed by thousands of specialists and researched for >60 yrs, electrodiagnostic testing rates poorly in evidence-based guidelines in part because there are no valid masked research studies. This study assesses whether the electrodiagnostic examination can be adequately masked. DESIGN: Prospective, controlled, masked trial. A total of 150 persons aged 55-80 yrs, thought clinically to be asymptomatic (n = 32), with low back pain (n = 46), or with spinal stenosis (n = 63), underwent needle electromyography and nerve conduction studies by specialists in physical medicine and rehabilitation who were not permitted to ask any clinical information or to perform a formal examination. Examiners rated potential bias and recorded clues that might bias the examination. RESULTS: Examiners noted potential for bias in conversation in 17 and due to pain behavior in one. Half of these potential unmaskings pointed away from the correct clinical diagnosis, leaving potential for bias in <6% of the subjects. The clinical diagnosis had no relationship to electrodiagnostician rating of pain behavior in response to testing or repositioning, to limb atrophy, and to arthritis (P > 0.05 all instances). CONCLUSIONS: The electrodiagnostic examination can be successfully masked. This information will help future research in electrodiagnostics meet the criteria of evidence-based medicine.

Spinal stenosis, back pain, or no symptoms at all? A masked study comparing radiologic and electrodiagnostic diagnoses to the clinical impression.

OBJECTIVE: To assess the relations between clinically recognized lumbar spinal stenosis and the conclusions of masked radiologists and electrodiagnosticians. DESIGN: Prospective, masked, double-controlled trial. SETTING: University spine center. PARTICIPANTS: One hundred fifty persons age 55 to 80 years with or without back pain and with or without magnetic resonance imaging (MRI)-demonstrated stenosis, screened for neuropathy risk, previous surgery, or cancer. INTERVENTIONS: Questionnaires on pain and function; ambulation testing and physical examination; and masked electrodiagnotics and MRI. MAIN OUTCOME MEASURE: Diagnostic impressions of the examining clinician, radiologist, and electrodiagnostician. RESULTS: Following application of post hoc exclusion criteria and elimination of patients due to incomplete or inadequate test data, the clinical diagnosis was lumbar stenosis in 50 subjects, back pain in 44 subjects, and no pain in 32 subjects. Radiologic and clinical impression had no relation (P = .80 vs asymptomatic, P = .99 vs back pain controls). Electrodiagnostic impression trended to relate to clinical impression (P = .14 vs asymptomatic, P = .09 vs back pain). Retrospective application of age-related electrodiagnostic norms for paraspinal electromyographic and limb motor unit changes, established in this study, reclassified 13 of the 17 asymptomatic persons whom the electrodiagnostician thought had stenosis. The clinical impression did correspond to history and physical examination findings typically associated with spinal stenosis and to the independent impression of a neurosurgeon who examined MRI and clinical, but not to the electrodiagnostic data. CONCLUSIONS: The impression obtained from an MRI scan does not determine whether lumbar stenosis is a cause of pain. Electrodiagnostic consultation may be useful, especially if age-related norms obtained in this study are applied.

Predictors of pain and function in persons with spinal stenosis, low back pain, and no back pain.

STUDY DESIGN: Longitudinal masked, double-controlled cohort study. OBJECTIVES: To determine prognosis and predictors of function and pain in persons with spinal stenosis. SUMMARY OF BACKGROUND DATA: The clinical syndrome of spinal stenosis is common and disabling, but not clearly related to anatomic measures. Prognosis not well studied. METHODS: Persons 55 to 80 years of age with and without stenosis on preliminary review of magnetic resonance imaging (MRI), and asymptomatic volunteers underwent screening, questionnaires, physical examination, ambulation testing, masked electromyogram (EMG), and masked MRI scans; these were repeated at >18 months. RESULTS: Twenty-three asymptomatic, 28 back pain, and 32 clinically diagnosed stenosis subjects underwent follow-up. Although initial and follow-up diagnosis tended to agree (kappa = 0.394, P < 001), there were substantial shifts between the three groups. Among persons with clinically diagnosed stenosis, every measure trended for improvement, including significant changes in pain, ambulation, and EMG. Ambulation velocity and Pain Disability Index at follow-up were predicted by initial disability measures. Pain was predicted by initial sleep difficulty but not initial pain. EMG and MRI did not predict function or pain. CONCLUSION: Clinically recognized spinal stenosis is fluctuating and largely improving, and in continuum with back pain and no symptoms. Since anatomic and neurologic deficits do not predict future function, they should not be weighed heavily in surgical risk-benefit discussions.