Reversible delayed leukoencephalopathy following intravenous heroin overdose.

We present serial neuropsychological, magnetic resonance (MR) imaging and EEG changes in a case of widespread CNS myelinopathy due to intravenous heroin overdose complicated by a period of prolonged unconsciousness. Following recovery from the acute overdose, the subject had the delayed onset of akinetic mutism with urinary incontinence. Sequential formal neuro-psychological assessments over 9 months showed evolution from severe global cerebral dysfunction to moderate disturbance of frontal lobe function. Almost complete resolution of diffuse white matter signal changes, accompanied by the development of a degree of volume loss, was evident on serial MR imaging over the same period, and generalized arrhythmic delta-range slowing on the EEG evolved int o a near normal pattern.