Benjamin Tolchin

Association of periodic and rhythmic electroencephalographic patterns with seizures in critically ill patients

Importance Periodic and rhythmic electroencephalographic patterns have been associated with risk of seizures in critically ill patients. However, specific features that confer higher seizure risk remain unclear. Objective To analyze the association of distinct characteristics of periodic and rhythmic patterns with seizures. Design, Setting, and Participants We reviewed electroencephalographic recordings from 4772 critically ill adults in 3 academic medical centers from February 2013 to September 2015 and performed a multivariate analysis to determine features associated with seizures. Interventions Continuous electroencephalography. Main Outcomes and Measures Association of periodic and rhythmic patterns and specific characteristics, such as pattern frequency (hertz), Plus modifier, prevalence, and stimulation-induced patterns, and the risk for seizures. Results Of the 4772 patients included in our study, 2868 were men and 1904 were women. Lateralized periodic discharges (LPDs) had the highest association with seizures regardless of frequency and the association was greater when the Plus modifier was present (58%; odds ratio [OR], 2.00, P < .001). Generalized periodic discharges (GPDs) and lateralized rhythmic delta activity (LRDA) were associated with seizures in a frequency-dependent manner (1.5-2 Hz: GPDs, 24%,OR, 2.31, P = .02; LRDA, 24%, OR, 1.79, P = .05; ≥ 2 Hz: GPDs, 32%, OR, 3.30, P < .001; LRDA, 40%, OR, 3.98, P < .001) as was the association with Plus (GPDs, 28%, OR, 3.57, P < .001; LRDA, 40%, P < .001). There was no difference in seizure incidence in patients with generalized rhythmic delta activity compared with no periodic or rhythmic pattern (13%, OR, 1.18, P = .26). Higher prevalence of LPDs and GPDs also conferred increased seizure risk (37% frequent vs 45% abundant/continuous, OR, 1.64, P = .03 for difference; 8% rare/occasional vs 15% frequent, OR, 2.71, P = .03, vs 23% abundant/continuous, OR, 1.95, P = .04). Patterns associated with stimulation did not show an additional risk for seizures from the underlying pattern risk (P > .10). Conclusions and Relevance In this study, LPDs, LRDA, and GPDs were associated with seizures while generalized rhythmic delta activity was not. Lateralized periodic discharges were associated with seizures at all frequencies with and without Plus modifier, but LRDA and GPDs were associated with seizures when the frequency was 1.5 Hz or faster or when associated with a Plus modifier. Increased pattern prevalence was associated with increased risk for seizures in LPDs and GPDs. Stimulus-induced patterns were not associated with such risk. These findings highlight the importance of detailed electroencephalographic interpretation using standardized nomenclature for seizure risk stratification and clinical decision making.

Effect of stimulus type and temperature on EEG reactivity in cardiac arrest

OBJECTIVE Electroencephalogram (EEG) background reactivity is a reliable outcome predictor in cardiac arrest patients post therapeutic hypothermia. However, there is no consensus on modality testing and prior studies reveal only fair to moderate agreement rates. The aim of this study was to explore different stimulus modalities and report interrater agreements. METHODS We studied a multicenter, prospectively collected cohort of cardiac arrest patients who underwent therapeutic hypothermia between September 2014 and December 2015. We identified patients with reactivity data and evaluated interrater agreements of different stimulus modalities tested in hypothermia and normothermia. RESULTS Of the 60 patients studied, agreement rates were moderate to substantial during hypothermia and fair to moderate during normothermia. Bilateral nipple pressure is more sensitive (80%) when compared to other modalities in eliciting a reactive background in hypothermia. Auditory, nasal tickle, nailbed pressure and nipple pressure reactivity were associated with good outcomes in both hypothermia and normothermia. CONCLUSIONS EEG reactivity varies depending on the stimulus testing modality as well as the temperature during which stimulation is performed, with nipple pressure emerging as the most sensitive during hypothermia for reactivity and outcome determination. SIGNIFICANCE This highlights the importance of multiple stimulus testing modalities in EEG reactivity determination to reduce false negatives and optimize prognostication.

Altered responsiveness in psychogenic nonepileptic seizures and its implication to underlying psychopathology

PURPOSE Altered responsiveness during psychogenic nonepileptic seizures (PNES) is a distinct semiological feature that may signal a psychological vulnerability. We hypothesized that altered responsiveness is related to difficulties with emotion tolerance, experiential avoidance, difficulty coping, dissociation and trauma and prior experiences of loss of awareness. METHODS 71 patients with video-EEG confirmed PNES were divided into two groups based on their responsiveness at the time of the captured event during long-term monitoring. Demographic information, clinical history and self-rated questionnaires highlighting psychopathology were compared between the groups. RESULTS 47 patients (66%) had altered responsiveness during their captured event. Married or partnered subjects were more represented in the altered responsiveness group. Experiential avoidance, as measured by the Acceptance and Action Questionnaire-II, and affect intolerance, as measured by the Affective Style Questionnaire, were significantly higher in the altered responsiveness group. The Connor Davidson Resilience Scale was significantly higher among intact responsiveness subjects. Subjects with altered responsiveness were more likely to have a family history of seizures, comorbid headaches, and loss of consciousness (LOC) during traumatic brain injury. There were no differences in measures of dissociation, somatization, mood or anxiety, or presence of psychiatric comorbidities, including PTSD or history of trauma. CONCLUSION Altered responsiveness during PNES is a marker of lower emotional resilience or ability to tolerate emotions among patients with PNES. Emotion management may be an important therapeutic target for these patients. Prior experiences with LOC also contribute to the presence of altered responsiveness. Trauma and dissociation did not differentiate responsiveness during PNES.

Response to 'Benefit effect of naloxone in benzodiazepines intoxication: Findings of a preliminary study'

We read with interest the recent study examining the use of naloxone to treat benzodiazepine intoxication. We praise the authors for exploring the potential for naloxone to treat benzodiazepine toxicity. Naloxone has been empirically used for decades in patients with a mental status depression from unknown cases. Those patients who ingested opioids will often respond while many other ingestions do not respond. Since your findings go against our understanding of receptor pharmacology (naloxone is not known to interact with the GABA receptors), we have a few questions regarding the methodology as well as how to interpret the results. Can you provide more details regarding the screening test for opioids? Since naloxone is a known antidote for opioid toxicity, it is very important to exclude their presence to validate the data obtained. For example, synthetic opioids such as methadone and fentanyl are not detected by an immunoassay, masking an effect of naloxone on reversing true opioid poisoning. Another concern we had about testing involves the benzodiazepines. While we understand the difficulty in analyzing serum for specific benzodiazepines, it is important to confirm that the patients consumed the benzodiazepine that they reported. Would screening of urine for the presence of a specific benzodiazepine be a reasonable means to confirm the history of ingestion? A patient’s history is often unreliable and may also make mistakes in the medication they take. Since the primary objective of this study was describing the patient’s clinical presentation based on the benzodiazepines they used, this would be an important consideration. Thank you for this interesting article.

Long-term adherence with psychiatric treatment among patients with psychogenic nonepileptic seizures

We conducted a prospective cohort study, examining long‐term adherence with psychiatric treatment among patients with psychogenic nonepileptic seizures (PNES). Subjects diagnosed with documented PNES were scheduled for 4 psychiatric visits. Survival analysis was performed, and covariates were assessed for association with time to nonadherence using Cox proportional hazard regression analysis. One hundred twenty‐three subjects were recruited and followed for up to 17 months. Eighty percent of subjects attended the first outpatient visit, 42% attended the second, 24% attended the third, and only 14% remained adherent through the fourth visit. Two covariates were associated with nonadherence: (1) a prior diagnosis of PNES (hazard ratio 1.57, P‐value .046); (2) a lower score on the Brief Illness Perception Questionnaire (BIPQ), signifying lower concern about ones illness (hazard ratio 0.77 for every 10‐point increment on the 80‐point scale, P‐value .008). Adherence with psychiatric treatment among patients with PNES is initially reasonably good but worsens rapidly over visits 2‐4. Risk factors for nonadherence include a history of a prior diagnosis of PNES, and a lower level of concern about the illness as assessed by a lower score on the BIPQ.

Status epilepticus caused by cerebral amyloid angiopathy-related inflammation

This report discusses a case of nonconvulsive status epilepticus, caused by cerebral amyloid angiopathy-related inflammation. Brain biopsy demonstrated cerebral amyloid angiopathy, with clinical and radiographic features indicative of a fluctuating inflammatory process. Immunomodulatory treatment with pulse steroids resulted in rapid and dramatic clinical and radiographic improvement. Cerebral amyloid angiopathy-related inflammation should be considered in the differential diagnosis of new-onset seizures after the age of 40, when associated with fluctuating multifocal T2 hyperintensities and petechial hemorrhages on gradient echo (GRE) or susceptibility-weighted (SWI) MRI sequences.

Liver transplant for intentional acetaminophen overdose and hepatic encephalopathy: a conflict between beneficence and justice.

ABSTRACTIn cases of severe acetaminophen-induced acute liver failure and hepatic encephalopathy, liver transplant can be the only real hope for neurologic recovery and indeed survival. In such cases, the bioethical principles of beneficence and justice often come into conflict. This article examines a case in which a neurologist managing an acetaminophen-overdose patient in the neurologic intensive care unit is faced with a conflict between her patient’s need for a liver transplant and the needs of other patients on the transplant list.

Medical Ethics Education for Neurology Residents: Where Do We Go from Here?

Abstract Neurologists regularly confront complex clinical scenarios that require the application of ethical principles to achieve a respectful and fair resolution. In this article, we describe the types of ethically precarious scenarios neurologists encounter, the current status of standards for ethics and communication training for neurology residents, and the present practice of ethics training in neurology residency programs. We make recommendations for optimizing bioethics training for neurology residents and suggest methods for assessing the efficacy of these training initiatives. We emphasize the current need for strengthening the practical bioethics skills of neurologists.

Nonepileptic Psychogenic Status Epilepticus

Psychogenic nonepileptic seizures (PNES) are a common and debilitating mimic of epileptic seizures. Prolonged PNES, lasting >20 min, are categorized as nonepileptic psychogenic status epilepticus (NEPS) and constitute the most important differential diagnosis for status epilepticus. NEPS is frequently mistaken for status epilepticus, and this has resulted in serious iatrogenic harm and even mortality. It is therefore essential to consider and rule out the diagnosis of NEPS in any patient presenting with apparent status epilepticus. Diagnosis can involve clinical history, seizure semiology, and other supportive tests, with video-electroencephalogram as the gold standard. This chapter reviews the etiology, epidemiology, diagnosis, treatment, and prognosis of NEPS. The differential diagnoses of mimics of convulsive and nonconvulsive status epilepticus, other than NEPS, are also reviewed.