Descriptive study of acute disseminated encephalomyelitis and evaluation of functional outcome predictors

Background: Outcome following Acute Disseminated Encephalomyelitis (ADEM) is variable and there are only limited studies from India.
Aim: The study aims to evaluate the predictors of functional outcome in a cohort of patients with ADEM.
Setting: Tertiary-care teaching hospital.
Materials and Methods: Patients admitted with the diagnosis of ADEM from 1999 to 2004 have been included. Clinical features and radiological findings were evaluated. Functional outcome at discharge was scored using modified Rankin Scale and patients were followed up regularly.
Statistical Analysis: Chi-Square test or Fisher′s exact test, and Student′s t test for comparison of categorical and continuous variables, respectively, and logistic regression for multivariate analysis.
Results: Sixty-one patients were evaluated (mean age 22±15.9 years, 1-65). Fifty-two patients had preceding febrile illness or vaccination with mean 9.1±12.5 days interval to first neurological symptom. Non-specific febrile illnesses were the commonest trigger. Commonest findings were motor signs (n=41), impaired consciousness (n=33), bladder symptoms (n=21), ataxia (n=15), and seizures (n=14). Between adult (mean age 30.1±13.1 years, 13-65, n=38), and pediatric (mean age 6.2±2.8 years, 1-12, n=23) patients, language disturbances were more common in the latter (P=0.047). MR imaging (n=35) demonstrated lesions mostly in frontoparietal white matter (n=23) and thalamus (n=15). Nine patients expired. Patients with poor functional outcome at discharge more often had impaired consciousness (P=0.038) and seizures (P=0.06). At follow-up (n=25), deficits included motor signs (n=15) and bladder symptoms (n=5).
Conclusions: ADEM has a wide range of neurological presentations and language disturbances are more common in pediatric patients. The presence of impaired consciousness, and possibly seizures, predict poor functional outcome at hospital discharge.

Keywords
Acute disseminated encephalomyelitis, impaired consciousness, modified rankin scale, outcome, prognosis, seizures