Comparison of clinical features between acute disseminated encephalomyelitis and classical multiple sclerosis

Abstract

Objective To improve differential diagnosis between acute disseminated encephalomyelitis ( ADEM) and classical multiple sclerosis ( CMS).Methods All 20 cases of ADEM and 24 cases of CMS were examined.Their epidemiological and clinical findings,laboratory features and magnetic resonance imaging ( MRI) data were analyzed using x2 test for categorical variables,Wilcoxon Rank-Sum tests for continuous variables.Results ADEM and CMS showed no sex predominance.Patients with ADEM ((27 ±15) years) were younger than CMS ((37 ±13) years,Z= -2.218,P =0.027).The following findings were more commonly seen in ADEM compared with CMS:predemyelinating infectious disease (75% vs 4%,x2 =23.652,P = 0.000),fever (65% vs 4%,x2 =18.609,P = 0.000),meningeal irritation sign (40% vs 0,x2 = 9.189,P =0.002),seizure (25% vs 0,x2 =4.514,P = 0.034),and encephalopathy.ADEM patients were more likely to present with blood leucocytosis ( (11.9 ± 5.8) ×109/L vs (8.0±3.2) ×109/L,Z= -2.030,P=0.042),high C-reactive protein (2.74 mg/L vs 0.49 mg/L,Z = - 3.028,P = 0.002),increased erythrocyte sedimentation rate (11.00 mm/h vs 7.00 mm/h,Z= -2.406,P =0.016),and cerebrospinal fluid leucocytosis (9 × 106/L vs 2×106/L,Z =- 2.781,P = 0.005).There were no differences in cerebrospinal fluid protein and oligoclonal band between the two groups.The following MRI lesions were more commonly seen in ADEM patients:cortical gray matter lesions (14/20,x2=15.213,P=0.000),basal ganglia gray matter lesions (14/20,x2 =8.910,P = 0.003),and brainstem lesions ( 14/20,x2 = 5.867,P = 0.015).In contrast,lesions in subcortical white matter (21/24,x2 = 17.628,P =0.000),periventricular area (21/24,x2 =15.213,P=0.000) and corpus callosum ( 14/24,x2 = 8.640,P = 0.003 ) were more common in the MRI image of CMS patients.The lesions in spinal cord were usually centrally distributed in ADEM (83% ),while peripherally in CMS (85%,x2 = 11.542,P = 0.001).The lesions had poorly defined margins in ADEM (95%),but well defined margins in CMS (75%,x2 =21.787,P = 0.000).Conclusion There are differences in epidemiological and clinical findings,laboratory features and MRI appearances between ADEM and CMS. Key words: Encephalomyelitis,acute disseminated; Multiple sclerosis; Diagnosis,differential