Aetiology and outcome of non-traumatic altered states of consciousness in north western Ethiopia.

Awareness of the relative prevalence of diseases causing altered states of consciousness (ASC) in a particular geographic locality could greatly facilitate the approach to patient management. This prospective study has, therefore, evaluated 202 patients with ASC admitted to the medical wards of GCMS teaching hospital in a two year period, between January 1994 and December 1995. ASC was defined as a clinical state manifested by conditions ranging from confusion and disorientation in person, place and time to stupor and deep coma. History, physical examination, limited laboratory tests and course of the patient in the hospital were used to identify the aetiology. There were 122 (60.4%) males and 80 (39.6%) females with male to female ratio of 3:2. Most of the patients, 122 (60.4%), belong to the age group below 40 years and the median age was 33 years (range = 15.84). The median duration of hospital stay was six days (range = 1-90). The commonest cause was infections, 111 (55%) followed by metabolic disorders, 45 (22.3%), structural lesions, 30 (14.9%) and poisoning, seven (3.5%). The aetiology was not identified in nine (4.5%) of the patients. Cerebral malaria was the commonest infectious cause followed by chronic meningitis and/or encephalitis. In hospital mortality rate was 60.4%. Unknown diagnosis, structural neurologic and metabolic causes were associated with increased mortality rate, with p values of 0.002, 0.009 and 0.015, respectively. The same was true for presence of HIV infection, P = 0.02. Since infectious causes are the commonest causes in our series, of which most are treatable with a relatively favourable outcome, critical evaluation for infections and early intervention is recommended. In addition, diagnostic facilities, especially for structural central nervous system lesions has to be improved because successful treatment and prognosis depends on the identification of a specific aetiology.