Faculty Bibliography

BACKGROUND AND OBJECTIVES:We compared heart rate variability (HRV) in sudden unexpected death in epilepsy (SUDEP) cases and living epilepsy controls. METHODS:This international, multicenter, retrospective, nested case-control study examined patients admitted for video-EEG monitoring (VEM) between January 1, 2003, and December 31, 2014, and subsequently died of SUDEP. Time domain and frequency domain components were extracted from 5-minute interictal ECG recordings during sleep and wakefulness from SUDEP cases and controls. RESULTS:= 0.209). CONCLUSIONS:Reduced short-term LFP, which is a validated biomarker for sudden death, was associated with SUDEP. Increased HFP was associated with longer survival and may be cardioprotective in SUDEP. HRV quantification may help stratify individual SUDEP risk. CLASSIFICATION OF EVIDENCE:This study provides Class III evidence that in patients with epilepsy, some measures of HRV are associated with SUDEP.

Task-specific focal dystonia is characterized by muscle contraction(s) during a specific task, resulting in abnormal postures or movements. Specifically, writer's cramp involves the upper extremity during the act of writing. Musician's dystonia has a highly variable presentation, and thus makes therapeutic options more limited. Treatments include oral pharmacologic agents, neuromodulation, surgery and, most often, botulinum toxin (BoNT) injection. Selection of target muscles for toxin injection continues to be an area of active research for these task-specific movements. We present a review of the literature selected from a predefined search of the MEDLINE and ClinicalTrials.gov databases. We include six controlled studies of botulinum toxin for the management of writer's cramp and focal task-specific dystonia (FTSD), including musician's dystonia. Overall, 139 patients were included across all studies, with 99 individuals injected for writer's cramp and the remaining 40 individuals with FTSD. The age range of all patients was 18-80 years old. We included studies that utilized only the BoNT-A serotype. These studies utilized various severity scales to quantify response to toxin injection, with ratings of instrument or pen control included as subjective ratings. Of the included 139 patients in this review, pooled data for toxin response show that 73% of patients who received the drug demonstrated improvement. Specific techniques for muscle localization and targeting were difficult to study as variable methods were employed. This remains an area of ongoing exploration.

OBJECTIVE:Pain specialists treat patients with headache and interface with those who use opioids more so than neurologists and headache specialists. We assessed headache medicine knowledge and needs of pain specialists. DESIGN/SETTING/METHODS:Cross-sectional online survey. SUBJECTS/METHODS:Members of the American Academy of Pain Medicine. METHODS:Survey was based on a prior survey on primary care providers' knowledge and needs and was iteratively updated by four headache specialists, two with pain medicine affiliations. RESULTS:Of the 105 respondents, 71.4% were physicians, 34.3% were women, and they averaged 20.0 ± 13.6 years in practice. The most common specialty was anesthesia (36.1%, n = 35/97) followed by neurology (14.4%, n = 14/97). About half of providers (55.7%, n = 34/61 and 53.3%, n = 32/60) were familiar with the American Academy of Neurology Guidelines for pharmacological migraine prevention and the Choosing Wisely Campaign recommendations for limiting neuroimaging and opioids. Less than half of all providers (39.7%, n = 23/58) were familiar with the American Headache Society guidelines for emergency management of migraine. Providers were aware of Level A evidence-based nonpharmacological therapies, with over three-fourths recognizing cognitive behavioral therapy (80.7%, n = 50/62) and biofeedback (75.8%, n = 47/62) as evidence-based interventions. About 80% of providers (n = 50/64) estimate making migraine diagnoses in ≤ 50% of their patients with headache. Providers consider starting preventive headache therapy at 7.1 ± 3.9 days/month and report referring 34.3%±34.2% of patients to behavioral interventions. CONCLUSIONS:Dissemination and implementation of headache guidelines is needed for pain medicine specialists. Providers may need help diagnosing migraine based on currently accepted guidelines and referring for evidence-based behavioral therapies.

OBJECTIVE:To update a 1996 American Academy of Neurology practice parameter. METHODS:The authors systematically reviewed literature published from January 1991 to March 2020. RESULTS:The long-term (24-60 months) risk of seizure recurrence is possibly higher among adults who have been seizure-free for 2 years and taper antiseizure medications (ASMs) vs those who do not taper ASMs (15% vs 7% per the 1 Class I article addressing this issue). In pediatric patients, there is probably no significant difference in seizure recurrence between those who begin tapering ASMs after 2 years vs 4 years of seizure freedom, and there is insufficient evidence of significant difference in risk of seizure recurrence between those who taper ASMs after 18 months of seizure freedom and those tapering after 24 months. There is insufficient evidence that the rate of seizure recurrence with ASM withdrawal following epilepsy surgery after 1 year of seizure freedom vs after 4 years is not significantly different than maintaining patients on ASMs. An epileptiform EEG in pediatric patients increases the risk of seizure recurrence. ASM withdrawal possibly does not increase the risk of status epilepticus in adults. In seizure-free adults, ASM weaning possibly does not change quality of life. Withdrawal of ASMs at 25% every 10 days to 2 weeks is probably not significantly different from withdrawal at 25% every 2 months in children who are seizure-free in more than 4 years of follow-up. RECOMMENDATIONS/CONCLUSIONS:Fourteen recommendations were developed.

The ability to process and respond to external input is critical for adaptive behavior. Why, then, do neural and behavioral responses vary across repeated presentations of the same sensory input? Ongoing fluctuations of neuronal excitability are currently hypothesized to underlie the trial-by-trial variability in sensory processing. To test this, we capitalized on intracranial electrophysiology in neurosurgical patients performing an auditory discrimination task with visual cues: specifically, we examined the interaction between prestimulus alpha oscillations, excitability, task performance, and decoded neural stimulus representations. We found that strong prestimulus oscillations in the alpha+ band (i.e., alpha and neighboring frequencies), rather than the aperiodic signal, correlated with a low excitability state, indexed by reduced broadband high-frequency activity. This state was related to slower reaction times and reduced neural stimulus encoding strength. We propose that the alpha+ rhythm modulates excitability, thereby resulting in variability in behavior and sensory representations despite identical input.

RATIONALE/BACKGROUND:Posttraumatic epilepsy (PTE) is a common cause of morbidity in children after a traumatic brain injury (TBI), occurring in 10-20% of children following severe TBI. PTE is diagnosed after two or more unprovoked seizures occurring 1-week post TBI. More often, studies have focused on children with epilepsy due to severe TBI. We aim to understand the utility of head computed tomography (HCT), EEG, and the risk of developing drug-resistant epilepsy in children after mild TBI. METHOD/METHODS:We retrospectively studied 321 children with TBI at a tertiary pediatric referral center during a 10-year period. Mild TBI was defined as loss of consciousness (LOC) or amnesia < 30 min, moderate TBI as LOC or amnesia between 30 min and 1 day, and severe TBI as LOC or amnesia > 1 day, subdural hemorrhage, or contusion. Multiple clinical variables were reviewed, including past and present antiepileptic drug(s), seizure control, and mode of injury. First and subsequent post-TBI EEGs/prolonged video-EEGs were obtained acutely, subacutely, and/or chronically (range, day 1-3 years, median 1 month). Descriptive analyses were conducted using medians and ranges for continuous data. Categorical data were reported using frequencies and percentages, while comparisons between groups were made using Fisher's exact test for small sample sizes. RESULTS:< 0.005. Six patients (75%) had MRIs, of which five (63%) were normal. Two patients (#1, 7) did not have MRIs, while one patient's (#4) MRI was unavailable. Five patients (63%) had a seizure <24 h post TBI, while the rest had seizures after the first week of injury. CONCLUSION/CONCLUSIONS:Children with epilepsy due to mild TBI, loss of consciousness, or amnesia < 30 min are more likely to have normal HCT and EEG and to be on 0-1 AED. Limitations of our study include the small sample size and retrospective design. The current findings add to the paucity of data in children who suffer from epilepsy due to mild TBI.