Classic ADEM is monophasic, with a history of usually a preceding illness or less commonly, a vaccination. It is characterised by an acute onset of focal neurologic symptoms, often with rapid deterioration of consciouness, after a variable latent period of several days to few months.

Classic ADEM is monophasic, with a history of usually a preceding illness or less commonly, a vaccination. It is characterised by an acute onset of focal neurologic symptoms, often with rapid deterioration of consciouness, after a variable latent period of several days to few months.

• Identical in adults and children
• Headache
• Fever, malaise
• Irritability
• Nausea and vomiting
• General neurological symptoms after 2-5 days^[1]

• Features of [encephalopathy]] comprising changes in behaviour and consciousness (46-73% of pediatric patients and 20-56% of adult cases)^[2] ranging in severity from lethargy to coma. Presence of encephalopathy differentiates pediatric ADEM from Multiple Sclerosis^[3].
• Confusion
• Psychosis

• Damage to occipital lobes: Homonymous visual field defects, cortical blindness
• Agraphia, aphasia, alexia, acalculia
• Sensory symptoms: Astereognosis ,agraphesthesia, loss of proprioception, vibration and temperature sensation
• Brainstem involvement (carries a poorer prognosis and a higher risk of fulminant disease course^[4]): Diplopia, dysphagia, dysarthria, vertigo, hearing loss, loss of taste and smell^[1]

Caused by lymphocytic infiltration of the meninges in 26-31% of cases

Other conditions should be excluded in the presence of the following atypical features of ADEM^[1]:

• Progressive onset
• Persistent headache
• Stroke-like events
• Recurrent seizures (predominant in pediatric cases)
• Neuropsychiatric symptoms