Alpha coma: A report

• Published in: Neurology India Vol. 65; no. 3; p. 640
• Main Authors: Parvathy, Giridas, Suraj, M M, Kabeer, K A, Shaji, C V
• Format: Journal Article
• Language: English
• Published: India Medknow Publications and Media Pvt. Ltd 01.05.2017; Medknow Publications & Media Pvt. Ltd
• Subjects: Brain damage; Brain waves; Cardiopulmonary resuscitation; Coma; CPR; Electroencephalography; Head injuries; Hypoxia; Measurement; Medical prognosis; Neurology; Patients; Trauma
• ISSN: 0028-3886; 1998-4022
• DOI: 10.4103/neuroindia.NI_205_16

Sir, Alpha coma, an electroencephalogram (EEG) pattern, characterized by a diffuse or widespread rhythmic activity in the alpha frequency band, is typically recorded in patients with profound coma. The most common etiologic factors of this pattern are hypoxic-ischemic encephalopathy, encephalitis, head trauma, metabolic disorders, and drug overdose. An 18-year old girl was brought in coma after an out-of-hospital cardiac arrest. On admission, she had a Glasgow coma score of 3/15 without other focal abnormalities on neurological examination, and was put on mechanical ventilation. A 16-channel EEG record was obtained at the initial evaluation after connecting the patient to the ventilator, using silver chloride disk electrodes placed at standard scalp sites according to the 10-20 international system. [2] This activity can be blocked by the destruction of both the amygdalae but not due to injury of the cerebral cortex, suggesting that the amygdala may serve as a pacemaker after the diffuse anoxic-ischemic insult, driving in turn, the thalamus, caudate nucleus, and cortex. [6] The survival rate of patients with post-hypoxic alpha coma seems to be higher with respiratory arrest than with cardiopulmonary arrest. [...]solely based on EEG patterns, it is often difficult to prognosticate the outcome in patients in a deep...