Elizabeth E. Gerard

American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology: 2012 version.

Continuous EEG Monitoring is becoming a commonly used tool in assessing brain function in critically ill patients. However, there is no uniformly accepted nomenclature for EEG patterns frequently encountered in these patients such as periodic discharges, fluctuating rhythmic patterns, and combinatio

Age, Rapid-Cycling, and Pharmacotherapy Effects on Ventral Prefrontal Cortex in Bipolar Disorder: A Cross-Sectional Study

BACKGROUND Neuroimaging data suggest that deficits in ventral prefrontal cortex (VPFC) function in bipolar disorder (BD) progress during adolescence and young adulthood. However, the developmental trajectory of VPFC morphological abnormalities in BD is unknown. This study investigated potential age-dependent volume abnormalities in VPFC in BD. METHODS Thirty-seven individuals diagnosed with BD I (14 adolescents, 10 young adults and 13 older adults) and 56 healthy comparison subjects (HC) participated in imaging. Gray and white matter volumes of VPFC were measured using high-resolution structural magnetic resonance imaging (MRI). We used a mixed model, repeated measures analysis to examine VPFC volumes across age groups while co-varying for total brain volume. Potential effects of illness features including rapid-cycling and medication were explored. RESULTS VPFC volumes declined with age (p < .001). The diagnosis-by-age group interaction was significant (p = .01). Relative to HC subjects, VPFC gray and white matter volumes were significantly smaller in BD patients only in young adulthood (p = .04). In participants with BD, VPFC volumes were significantly smaller in participants with rapid-cycling than participants without rapid-cycling (p = .02). Conversely, current use of medication was associated with larger VPFC gray matter volumes (p = .005), independent of age. CONCLUSIONS These preliminary findings suggest the presence of a more rapid initial decline in VPFC volumes with age in adolescents and young adults with BD than HC. These findings also suggest that the rapid-cycling subtype of BD is associated with larger VPFC volume deficits than the non-rapid-cycling subtype, and that pharmacotherapy may have trophic or protective effects on VPFC volumes in BD patients.

Consensus Statement on Continuous EEG in Critically Ill Adults and Children, Part I: Indications

Introduction: Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. Methods: The Critical Care Continuous EEG Task Force of the American Clinical Neurophysiology Society developed expert consensus recommendations on the use of CCEEG in critically ill adults and children. Recommendations: The consensus panel recommends CCEEG for diagnosis of nonconvulsive seizures, nonconvulsive status epilepticus, and other paroxysmal events, and for assessment of the efficacy of therapy for seizures and status epilepticus. The consensus panel suggests CCEEG for identification of ischemia in patients at high risk for cerebral ischemia; for assessment of level of consciousness in patients receiving intravenous sedation or pharmacologically induced coma; and for prognostication in patients after cardiac arrest. For each indication, the consensus panel describes the patient populations for which CCEEG is indicated, evidence supporting use of CCEEG, utility of video and quantitative EEG trends, suggested timing and duration of CCEEG, and suggested frequency of review and interpretation. Conclusion: CCEEG has an important role in detection of secondary injuries such as seizures and ischemia in critically ill adults and children with altered mental status.

Developmental processes and brain imaging studies in Tourette syndrome

OBJECTIVES It is often difficult to discern how findings of a neuroimaging study relate to the pathophysiology of an illness because imaging correlates may variously represent causes, consequences, or epiphenomena of the condition. The objective of this paper is to exemplify the complexities of interpreting neuroimaging data by reviewing anatomical and functional studies of Tourette syndrome (TS). METHODS Medline and Psychological Abstracts (PsycInfo) databases were searched for functional and anatomical neuroimaging studies of TS. RESULTS 9 anatomical and 21 functional cross-sectional imaging studies of TS contributed to this review. Anatomical studies comparing TS patients to age-matched controls have found that lenticular nucleus volumes are reduced in TS adults, while caudate nucleus volumes are reduced in both adults and children with TS. In a study of the cerebral cortex, prefrontal volumes in TS adults were smaller, but in TS children were larger than in those of age-matched controls. Complementing the anatomical findings of reduced volumes of the caudate nucleus in TS, functional studies have suggested that frontal-striatal projections play an important role in the regulation of tic symptoms. The majority of functional studies to date, however, have been limited to the study of adults. These functional studies have yielded variable results that have limited generalizability to the pathophysiology of children with TS. CONCLUSIONS Although many of the findings in TS imaging may represent pathological causes of the disease, they may also be indicative of compensatory changes in the nervous system of TS subjects. Prospective studies of young children at risk will be necessary to help clarify the relationship between brain abnormalities and the course of the disease.

New-onset refractory status epilepticus Etiology, clinical features, and outcome

Objectives: The aims of this study were to determine the etiology, clinical features, and predictors of outcome of new-onset refractory status epilepticus. Methods: Retrospective review of patients with refractory status epilepticus without etiology identified within 48 hours of admission between January 1, 2008, and December 31, 2013, in 13 academic medical centers. The primary outcome measure was poor functional outcome at discharge (defined as a score >3 on the modified Rankin Scale). Results: Of 130 cases, 67 (52%) remained cryptogenic. The most common identified etiologies were autoimmune (19%) and paraneoplastic (18%) encephalitis. Full data were available in 125 cases (62 cryptogenic). Poor outcome occurred in 77 of 125 cases (62%), and 28 (22%) died. Predictors of poor outcome included duration of status epilepticus, use of anesthetics, and medical complications. Among the 63 patients with available follow-up data (median 9 months), functional status improved in 36 (57%); 79% had good or fair outcome at last follow-up, but epilepsy developed in 37% with most survivors (92%) remaining on antiseizure medications. Immune therapies were used less frequently in cryptogenic cases, despite a comparable prevalence of inflammatory CSF changes. Conclusions: Autoimmune encephalitis is the most commonly identified cause of new-onset refractory status epilepticus, but half remain cryptogenic. Outcome at discharge is poor but improves during follow-up. Epilepsy develops in most cases. The role of anesthetics and immune therapies warrants further investigation.

Consensus Statement on Continuous EEG in Critically Ill Adults and Children, Part II: Personnel, Technical Specifications and Clinical Practice

Introduction: Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. Methods: The Critical Care Continuous EEG Task Force of the American Clinical Neurophysiology Society developed expert consensus recommendations on the use of CCEEG in critically ill adults and children. Recommendations: The consensus panel describes the qualifications and responsibilities of CCEEG personnel including neurodiagnostic technologists and interpreting physicians. The panel outlines required equipment for CCEEG, including electrodes, EEG machine and amplifier specifications, equipment for polygraphic data acquisition, EEG and video review machines, central monitoring equipment, and network, remote access, and data storage equipment. The consensus panel also describes how CCEEG should be acquired, reviewed and interpreted. The panel suggests methods for patient selection and triage; initiation of CCEEG; daily maintenance of CCEEG; electrode removal and infection control; quantitative EEG techniques; EEG and behavioral monitoring by non-physician personnel; review, interpretation, and reports; and data storage protocols. Conclusion: Recommended qualifications for CCEEG personnel and CCEEG technical specifications will facilitate standardization of this emerging technology.

Imaging Inflammation in a Patient with Epilepsy Due to Focal Cortical Dysplasia

Evidence from animal models and examination of human epilepsy surgery specimens indicates that inflammation plays an important role in epilepsy. Positron emission tomography (PET) using [C11]PK11195, a marker of activated microglia, provides a means to visualize neuroinflammation in vivo in humans. We hypothesize that in patients with active epilepsy, [C11]PK11195 PET (PK‐PET) may be able to identify areas of focally increased inflammation corresponding to the seizure onset zone.

Continuous EEG monitoring: a survey of neurophysiologists and neurointensivists.

Continuous EEG monitoring (cEEG) of critically ill adults is being used with increasing frequency, and practice guidelines on indications for cEEG monitoring have recently been published. However, data describing the current practice of cEEG in critically ill adults is limited. We aimed to describe the current practice of cEEG monitoring in adults in the United States.

Assessment of a quasi-piezoelectric mattress monitor as a detection system for generalized convulsions

The risk of sudden unexpected death in epilepsy (SUDEP) is highest with nocturnal, unattended generalized convulsions, and basic resuscitation may be able to prevent SUDEP. This study investigates an under-mattress device (ElectroMechanical Film - Emfit®) which is triggered by rhythmic motor activity of a specifiable duration, frequency, and intensity using a quasi-piezoelectric material sensitive to changes in mattress pressure. The device was tested during inpatient video-EEG monitoring. Eighteen GTCSs were recorded, 10 out of wakefulness and 8 out of sleep. Sixteen of the 18 seizures (89%) resulted in Emfit® activation with both false negative alarms occurring during wakefulness. On average, the device was activated within 9 s of onset of bilateral clonic motor movements (range: -37 to +39 s) and occurred, on average, 45 s before seizure end (range: 19 to 76 s). Only 21 false alarms were encountered, all occurring during wakefulness (PPV: 43%). The data suggest that the Emfit® detection device has a high predictive value for generalized convulsions, offers caregivers a reliable and early warning to assist the patient during convulsions, and may be a novel way to prevent SUDEP.

Ictal central apnea as a predictor for sudden unexpected death in epilepsy

Epidemiological evidence associating ictal hypoventilation during focal seizures with a heightened risk for subsequent sudden unexpected death in epilepsy (SUDEP) is lacking. We describe a patient with temporal lobe epilepsy with two focal seizures recorded in the epilepsy monitoring unit that were associated with central apnea lasting 57 and 58 seconds. During these events, she demonstrated oxygen desaturation down to 68 and 62%. The patient subsequently died at home from autopsy-confirmed SUDEP. The family was not alerted of any seizure activity by the auditory alarm system in her room nor by sleeping in the adjacent room with open doors. This case emphasizes the fact that ictal hypoxia and SUDEP may occur in seizures without noticeable convulsive activity. The report gives credibility to the growing body of literature suggesting that epilepsies affecting the autonomic nervous system may predispose to SUDEP independent of the effects of a secondary generalized convulsion.