Long-term neurotoxic effects of dimethylamine borane intoxication

Objectives: To investigate the long-term neurotoxic effects in a patient with acute dimethylamine borane (DMAB) intoxication. Patients: A 38-year-old man, working in a semiconductor factory, with acute DMAB intoxication presented with confusion, and drowsiness, followed by cognitive impairments and motor-predominant axonal polyneuropathy. Investigations: We performed serial neurobehavioral assessments and functional neuroimaging studies, including brain ^99mTc-TRODAT single photon emission computed tomography (SPECT) and brain positron emission tomography (PET) scan to monitor the long-term central nervous system (CNS) effects of DMAB intoxication. Results: Neurobehavioral tests revealed a persistent impairment in episodic memory of visual retention semantic category retrieval and working memory of digit span (backward). Brain ^99mTc-TRODAT SPECT scan showed a lower radioactivity uptake in the left striatum and F-18 FDG PET scan revealed a relatively decreased cerebral metabolism at the anterior cingulate gyrus and both frontal regions. Follow-up neurobehavioral tests showed that the cognitive improvements were mainly documented in intelligence, attention function, conceptual shift, perceptual motor speed, verbal learning and working memory but were limited in visual memory and executive functions. Conclusion: Patients with acute DMAB intoxication may have a long-lasting CNS toxicity on the cognitive dysfunction, parkinsonism, and an impaired metabolic activity of the brain. Clinical improvements may sustain during the long-term follow-up period.