Nonconvulsive Seizures of Traumatic Brain Injury Patients / 대한신경손상학회지

OBJECTIVE: Seizures are common consequence of traumatic brain injury and have been reported in clinical series as an incidence of 15% to 22%. Among them, nonconvulsive seizures (NCS) are often unrecognized during the early period of neurosurgical hospitalization because their clinical presentations can be misunderstood as consequent symptoms of clinical course, and the diagnosis can be confirmed only by the electroencephalographic (EEG) recording. METHODS: We retrospectively reviewed our clinical database of traumatic brain injury (TBI) patients admitted between March 2008 and September 2012. Twenty one patients with suspicious symptoms of NCS, such as decrease of consciousness, aphasia or irritability, were included. Routine wake and sleep EEG or bedside continuous EEG monitoring were done in all patients. RESULTS: Ten out of twenty-one patients showed abnormal activities on EEG. Ictal discharges were documented on four patients. Based on clinical symptoms and EEG findings, these four patients were diagnosed as NCS. Two out of four NCS patients showed EEG findings of nonconvulsive status epilepticus (NCSE). Another six patients with abnormal EEG activities were considered as 'suspicious NCS' because only interictal activities were recorded on EEG but increasing dose or adding on antiepileptics relieved their symptoms. All NCS/NCSE were successfully controlled by appropriate antiepileptic therapy. CONCLUSION: Our result showed that NCS was diagnosed in about 20% of patients with suspicious symptoms. There's a possibility that actual NCS might have happened more. Because untreated NCS/NCSE might cause worse clinical outcome, careful observation and urgent EEG recordings should be considered in a patient with suspicious NCS symptoms.

Clinical Efficacy of Acute Monitoring Cortical Activity Using Subdural Strip Electrode after Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: Decompressive craniectomy is widely used in cases of uncontrolled intracranial hypertension, including traumatic brain injury or acute stroke. Physiological monitorings, such as intracranial pressure or electroenecephalography (EEG) are critical for patients in the acute phase. We retrospectively reviewed our experience of continuous electrocorticography (ECoG) monitoring by subdural strip electrode in patients who performed decompressive craniectomy and assessed its clinical efficacy. METHODS: Patients who underwent decompressive craniectomy because of severe intracranial hypertension were included. 4 Channel strip electrodes were inserted on the frontal cortex before closure. 24-hour continuous monitoring of ECoG was done to identify abnormal electrical activity. The level of consciousness was assessed according to Glasgow Coma Scale (GCS). In patients with malignant intracranial hypertension, barbiturate coma therapy was considered. RESULTS: Fifteen patients (9 men and 6 women) were included and the mean age was 55.7 years (from 17 to 80). The initial mean GCS score was 7.9 (from 3 to 14). In six out of fifteen patients, abnormal spike activities were identified, and one of these six patients was diagnosed as nonconvulsive status epilepticus (NCSE). Cortical spreading depression (CSD) was suspected in five. Three patients underwent barbiturate coma therapy and ECoG monitoring of these patients showed typical burst suppression pattern, which was used for indicator of therapeutic level. The mean duration of strip electrode and ECoG monitoring was 3.5 days, and there was no complication. CONCLUSION: Continuous ECoG monitoring using subdural strip electrode was useful to detect abnormal brain activity in the acute period after decompressive craniectomy.