CT and MR imaging of spongiform leukoencephalopathy after heroin vapor inhalation

Objective: To summarize the CT and MRI features of spongiform leucoencephalopathy after heroin vapor inhalation. Methods: The clinical characteristic, CT and MRI of 5 cases and biopsy of 1 case with heroin vapor inhalation induced spongiform leukoencephalopathy were analyzed. Results: CT and MRI appearances of spongiform leucoencephalopathy after heroin vapor inhalation were as follow: (1) Brain CT and MRI showed extensive symmetrical white matter lesions within bilateral cerebral and cerebellar hemispheres, the brainstem, and posterior limbs of the internal capsule. The cerebellum was heavily impaired. The most outstanding characteristics of the lesion was ring-like or butterfly-like in shape with clear margin in cerebellar hemispheres. (2) The lesion was bilateral and symmetrical. The margin of the lesion was clear. (3) A computed tomographic scan showed hypointense lesions. T1-weighted magnetic resonance imaging (MRI) showed hypointense lesions and T2-weighted MRI showed hyperintense lesions. (4) No enhancement with Gd-DTPA was revealed. (5) Spongiform vacuoles degeneration of white matter was the main morphological change by biopsy. Conclusion: Spongiform leukoencephalopathy should be considered if a patient showed acute cerebellar signs who had a history of inhaling heroin pyrolysate. The imaging manifestation of this disease is typical and the diagnosis can be made by head CT or MRI