DELAYED SPONGIFORM LEUKOENCEPHALOPATHY AFTER HEROIN ABUSE

Here we report the clinical and pathological findings in a 30-year-old drug addict in whom an intravenous injection of heroin led to reversi ble coma with respiratory depression and heart failure. On regaining c onsciousness, the patient was found to have rhabdomyolysis with renal failure requiring dialysis and peripheral neuropathy. Three weeks late r his neurological condition suddenly deteriorated and delayed encepha lopathy developed, leading to death 20 days later. The neuropathologic al study of the brain disclosed pale, spongy myelin with diffuse react ive astrogliosis and microglial proliferation, without hypoxic necroti c lesions. The cerebral and cerebellar cortices were unchanged. The ab sence of typical hypoxic lesions and the presence of spongiosis with m assive astrocytosis distinguished this case from the previously report ed cases of delayed leukoencephalopathy following severe hypoxia. An i mmunocytochemical study designed to exclude an underlying alteration o f the metabolic oxidative pathway detected normal expression of the re spiratory chain complexes IV, III and V. Despite the absence of an oxi dative chain alteration in our patient, we cannot exclude the possibil ity that an individual predisposition played a pathogenetic role in th is delayed leukoencephalopathy.