Regional attenuation without delta (RAWOD): a distinctive EEG pattern that can aid in the diagnosis and management of severe acute ischemic stroke.

Acute thrombolysis with recombinant tissue plasminogen activator (tPA) is the only treatment of proven effectiveness in acute ischemic stroke (AIS). Cerebral edema (CE) is the most feared and fatal complication of AIS. For both of these conditions, patient selection for treatment and timing of intervention are crucial but controversial issues. Conventional diagnostic tools for AIS, including the neurological exam, computerized cerebral tomography (CT) Scan, and magnetic resonance imaging (MRI) have not as yet been able to determine which patients are the best risk-benefit candidates for thrombolysis, nor are they sensitive to the early detection of patients at risk for cerebral edema. This article suggests that the use of Emergency EEG (EmEEG) in AIS can reveal a distinctive EEG pattern that adds value to the selection of patients for thrombolytic and cerebral edema treatment. This pattern, called RAWOD (Regional Attenuation WithOut Delta) can identify patients with massive AIS earlier than CT or MRI. Patients with RAWOD are unlikely to benefit from thrombolysis but may be candidates for early surveillance and intervention for cerebral edema.