Diffusion-weighted magnetic resonance imaging in a case of methanol intoxication

Methanol intoxication is an uncommon clinical problem leading to profound metabolic acidosis with serious neurological deterioration. We describe methanol induced brain lesions on diffusion-weighted MR images and discuss the pathophysiology of these lesions in light of diffusion changes.

Brain imaging was performed in a 32 year-old man in a coma with focal neurological signs. Bilateral putaminal [hyperintensity] was seen on fast spin echo T2-weighted sequences, on Fluid Attenuated Inversion Recovery (FLAIR) and on diffusion weighted images. Decreased ADC values were observed bilaterally in the putamina. In addition, FLAIR images showed diffuse hypersignal in the subarachnoidal space. The patient showed rapid neurological deterioration while blood chemical tests revealed a severe metabolic acidosis and plasma methanol levels of 21 mmol/L. The patient died from hepatic failure thirty six hours after admission.

Although decreased ADC values on diffusion-weighted imaging are commonly associated with arterial ischemic stroke, this pattern can also be observed in the case of putaminal necrosis following methanol ingestion.