Early Detection of Cerebral Herniation by Continuous Electroencephalography and Quantitative Analysis

Continuous electroencephalography (cEEG) and quantitative analysis of EEG (qEEG) are used in various circumstances such as detecting seizures, identifying acute or delayed cerebral ischemia, monitoring sedative therapy, or assessing prognosis. The authors report 2 cases: (1) Case #1 was a patient with unilateral cerebral edema and uncal herniation with asymmetric cEEG and qEEG changes detected an hour before clinical examination changes were noted and (2) Case #2 was a patient with diffuse cerebral edema and trans-tentorial herniation with symmetric cEEG and qEEG changes detected an hour before clinical examination changes were noted. These cases demonstrate the ability of cEEG and qEEG in early detection of different types of cerebral herniation. qEEG can be utilized by intensive care unit (ICU) staff not trained in EEG interpretation as a surveillance method to detect cerebral herniation, which may provide an opportunity for early intervention in high-risk patients.

Spatial Attention in Serial Order Working Memory: An EEG Study

Theoretical models explaining serial order processing link order information to specified position markers. However, the precise characteristics of position marking have remained largely elusive. Recent studies have shown that space is involved in marking serial position of items in verbal working memory (WM). Furthermore, it has been suggested, but not proven, that accessing these items involves horizontal shifts of spatial attention. We used continuous electroencephalography recordings to show that memory search in serial order verbal WM involves spatial attention processes that share the same electrophysiological signatures as those operating on the visuospatial WM and external space. Accessing an item from a sequence in verbal WM induced posterior “early directing attention negativity” and “anterior directing attention negativity” contralateral to the position of the item in mental space (i.e., begin items on the left; end items on the right). In the frequency domain, we observed posterior alpha suppression contralateral to the position of the item. Our results provide clear evidence for the involvement of spatial attention in retrieving serial information from verbal WM. Implications for WM models are discussed.

Intravenous brivaracetam for the management of refractory focal non-convulsive status epilepticus

Diagnosis and management of status epilepticus (SE), including non-convulsive status epilepticus (NCSE), is challenging, with a reported 30%–50% of epilepticus patients not responding to available antiseizure medications (ASMs). Injectable benzodiazepines, fosphenytoin, valproate, levetiracetam, lacosamide and phenobarbital are commonly used for treating SE. Brivaracetam, a new ASM, with higher affinity and greater selectivity for the synaptic vesicle glycoprotein 2A than levetiracetam, has been approved as monotherapy or adjunct for treatment of focal onset seizures. Brivaracetam may have a role in the management of SE. However, limited data exist on brivaracetam’s efficacy in SE. We describe a patient case with focal NCSE refractory to levetiracetam, fosphenytoin, lacosamide and valproate who demonstrated clinical and electrographic improvement on continuous electroencephalography monitoring after brivaracetam administration.

Does the first hour of continuous electroencephalography predict neonatal seizures?

ObjectiveProlonged continuous video-electroencephalography (cEEG) is recommended for neonates at risk of seizures. The cost and expertise required to provide a real-time response to detected seizures often limits its utility. We hypothesised that the first hour of cEEG could predict subsequent seizures.Design and settingRetrospective multicentre diagnostic accuracy study.Patients266 term neonates at risk of seizure or with suspected seizures.InterventionThe first hour of cEEG was graded by expert and novice interpreters as normal, mildly, moderately or severely abnormal; seizures were identified.Main outcome measuresAssociation between abnormalities in the first hour of cEEG and the presence of seizures during total cEEG monitoring.Results50/98 (51%) of neonates who developed seizures had their first seizure in the first hour of cEEG monitoring. The ‘time-to-event’ risk of seizure from 0 to 96 hours was 0.38 (95% CI 0.32 to 0.44) while the risk in the first hour was 0.19 (95% CI 0.15 to 0.24). cEEG background was normal in 48% of neonates, mildly abnormal in 30%, moderately abnormal in 13% and severely abnormal in 9%. Inter-rater agreement for determination of background was very good (weighted kappa=0.81, 95% CI 0.72 to 0.91). When neonates with seizures during the first hour were excluded, an abnormal background resulted in 2.4 times increased risk of seizures during the subsequent monitoring period (95% CI 1.3 to 4.4, p<0.003) while a severely abnormal background resulted in a sevenfold increased risk (95% CI 3.4 to 14.3, p<0.0001).ConclusionsThe first hour of cEEG in at-risk neonates is useful in identifying and predicting whether seizures occur during cEEG monitoring up to 96 hours. This finding enables identification of high-risk neonates who require closer observation.

Long-Term Undiagnosed Nonconvulsive Status Epilepticus Identified by Urgent Electroencephalography with Hyperventilation Activation

Nonconvulsive status epilepticus (NCSE) might be underdiagnosed in cases where clinical symptoms are ambiguous. If a patient exhibits ictal psychiatric symptoms such as NCSE presentation and is misdiagnosed as having a psychiatric disorder, the patient may be treated in psychiatry settings, where continuous electroencephalography (cEEG), the gold standard for NCSE diagnosis, is typically not used. Herein, we report our experience with a patient having NCSE who exhibited psychiatric symptoms and remained misdiagnosed for many years. We also included a brief review of the relevant literature. Our experience with this patient presents two clinically significant points: (1) clinicians should consider NCSE in the differential diagnosis of interictal psychosis when patients with epilepsy, in whom the seizure type is unknown, repeatedly present transient psychiatric symptoms, and (2) urgent EEG with hyperventilation activation during acute periods may help diagnose patients with suspected NCSE.