Continuous versus Routine Electroencephalography in the Intensive Care Unit: A Review of Current Evidence.

BACKGROUND: Electroencephalography (EEG) has long been used to detect seizures in patients with disorders of consciousness. In recent years, there has been a drastically increased adoption of continuous EEG (cEEG) in the intensive care units (ICUs). Given the resources necessary to record and interpret cEEG, this is still not available in every center and widespread recommendations to use continuous instead of routine EEG (typically lasting 20 min) are still a matter of some debate. Considering recent literature and personal experience, this review offers a rationale and practical advice to address this question. SUMMARY: Despite the development of increasingly performant imaging techniques and several validated biomarkers, EEG remains central to clinicians in the intensive care unit and has been experiencing expanding popularity for at least 2 decades. Not only does EEG allow seizure or status epilepticus detection, which in the ICU often present without clinical movements, but it is also paramount for the prognostic evaluation of comatose patients, especially after cardiac arrest, and for detecting delayed ischemia after subarachnoid hemorrhage. At the end of the last Century, improvements of technical and digital aspects regarding recording and storage of EEG tracings have progressively led to the era of cEEG and automated quantitative analysis. KEY MESSAGES: As compared to repeated rEEG, cEEG in comatose patients does not seem to improve clinical prognosis to a relevant extent, despite allowing a more performant of detection ictal events and consequent therapeutic modifications. The choice between cEEG and rEEG must therefore always be patient-tailored.

Benign EEG for prognostication of favorable outcome after cardiac arrest: A reappraisal.

AIM: The current EEG role for prognostication after cardiac arrest (CA) essentially aims at reliably identifying patients with poor prognosis ("highly malignant" patterns, defined by Westhall et al. in 2014). Conversely, "benign EEGs", defined by the absence of elements of "highly malignant" and "malignant" categories, has limited sensitivity in detecting good prognosis. We postulate that a less stringent "benign EEG" definition would improve sensitivity to detect patients with favorable outcomes. METHODS: Retrospectively assessing our registry of unconscious adults after CA (1.2018-8.2021), we scored EEGs within 72 h after CA using a modified "benign EEG" classification (allowing discontinuity, low-voltage, or reversed anterio-posterior amplitude development), versus Westhall's "benign EEG" classification (not allowing the former items). We compared predictive performances towards good outcome (Cerebral Performance Category 1-2 at 3 months), using 2x2 tables (and binomial 95% confidence intervals) and proportions comparisons. RESULTS: Among 381 patients (mean age 61.9 ± 15.4 years, 104 (27.2%) females, 240 (62.9%) having cardiac origin), the modified "benign EEG" definition identified a higher number of patients with potential good outcome (252, 66%, vs 163, 43%). Sensitivity of the modified EEG definition was 0.97 (95% CI: 0.92-0.97) vs 0.71 (95% CI: 0.62-0.78) (p < 0.001). Positive predictive values (PPV) were 0.53 (95% CI: 0.46-0.59) versus 0.59 (95% CI: 0.51-0.67; p = 0.17). Similar statistics were observed at definite recording times, and for survivors. DISCUSSION: The modified "benign EEG" classification demonstrated a markedly higher sensitivity towards favorable outcome, with minor impact on PPV. Adaptation of "benign EEG" criteria may improve efficient identification of patients who may reach a good outcome.

Pearls and Oy-sters: Post-dural Puncture Headache, Cerebral Sinus Venous Thrombosis, and Reversible Cerebral Vasoconstriction Syndrome in the Peripartum.

We report the case of a 34-year-old female patient complaining of headaches one day after childbirth, initially interpreted as post-dural puncture headache (PDPH) and treated successfully with an epidural blood patch. Five days later, she presented an acute proportional right sensorimotor hemisyndrome and a new onset left-sided headache, attributed to a venous stroke from left-sided cerebral sinus venous thrombosis (CSVT). Simultaneously, we found radiological signs of reversible cerebral vasoconstriction syndrome (RCVS), considered as asymptomatic. We started the patient on anticoagulant therapy and she showed full motor recovery at the 3-month clinical follow-up.PDPH, CSVT and RCVS are well-known neurological complications of the peripartum period. All three conditions present with headaches and headache features may overlap, masking co-occurrence and making accurate diagnosis (differentiation) of these diseases difficult. Each disease can potentially lead to disabling deficits, but all respond to specific treatment.Knowledge of the causes of headaches in the peripartum period, their specific clinical characteristics and potential complications helps to prioritize and interpret diagnostic tests to offer appropriate therapy.