Non-Convulsive Status Epilepticus (NCSE) in ICU: Bedside Usefulness of TCD in Comatose Patient Diagnosis. When the EEG Is Too Far

Abstract

Points 1. Nonconvulsive status epilepticus (NCSE) is an important cause for unexplained impairment of consciousness, particularly in the intensive care unit (ICU). 2. Generation of abnormally prolonged or repeatedly recurrent brain electrical activity represents a metabolic burden not only on the neurons but also on the glial cells. This should be coupled by increase in cerebral blood flow (CBF). 3. The merits of the TCCS (transcranial color-coded duplex sonography) are being available, fast, bedside, safe, repeatable, and not interfering with continuous monitoring in the ICU. 4. TCCS assessment can help not only in diagnosis and follow-up of NCSE/IIC, but also in identifying the underlying etiology: arterial stenosis as a cause of acute ischemic stroke (AIS), dural venous sinus thrombosis, hydrocephalus, increased of ICP (by MLS, ONSD, and papilledema measurements) as in cases caused of space-occupying lesions (SOLs) (neoplasms, intra-and extra-axial hematoma, etc.). 5. Indirect assessment of cerebral blood flow (CBF) through cerebral blood flow velocities (CBFVs) measurement using TCD/TCCS was the most studied application of neurosonology in epileptic seizures, due to its ability to provide realtime evaluation at bedside. 6. EEG is the gold standard for diagnosis of NCSE/IIC; however, it can be unavailable or not conclusive enough. In these cases, vascular imaging can help to establish the diagnosis.