Etiology, neurologic correlations, and prognosis in alpha coma

Objective: To determine the factors affecting prognosis in alpha coma (AC). Methods: Retrospective review of 36 study patients, 36 control coma patient s matched for age and etiology, and meta-analysis of 335 cases in the world literature. Results: Principal causes were cardiorespiratory arrest (CRA) (21 patients) ; infection, metabolic dysfunction, head trauma (3 each); and drugs, stroke and hypoxia (2 each). Outcome was predicated by EEG reactivity to noxious stimuli. Fourteen of the 15 patients with reactive EEGs, had measurable out come, 8 awoke - all but two had etiologies other than CRA. Fourteen of 19 p atients without EEG reactivity died; two had support discontinued and 3 awo ke. Following CRA, 16/21 patients died and 3 had support discontinued. Only 3 patients made a good recovery - all with toxic or metabolic etiologies. Literature meta-analysis of 335 cases showed that overall, AC carried a poo r prognosis (76% died). CRA (226 cases) had an 88% mortality; strokes (29 c ases), a 90% mortality; hypoxia without cardiac arrest (28 cases), a 61% mo rtality; drug-induced AC (25 cases), an 8% mortality. Conclusions: Although the cause of AC largely predicts outcome, EEG reactiv ity in AC predicted survival: most patients with reactivity awoke; most of those without, died. Few survivors had meaningful recovery. (C) 1999 Elsevi er Science Ireland Ltd. All rights reserved.