A study of cognitive functions in methyl-iso-cyanate victims one year after bhopal accident

There is a paucity of information regarding the late effects of methyl-iso-cyanate (MIC) poisoning. In this study, the clinical and cognitive functions of 52 MIC victims were evaluated one year after the Bhopal gas accident. There were 15 severely, 14 moderately, and 23 mildly affected patients. Their mean age was 38.2 (range 15-65) years and 30 patients were males. Their clinical picture was dominated by respiratory symptoms in 36 patients, of which 17 had abnormal chest radiographs. Neurological examination of these patients was normal. Psychometry in 33 patients revealed significant impairment of standard progressive matrices (SPM), associate learning and motor speed and precision tests (p < 0.01) in severely exposed MIC patients. In the moderately affected group associate learning and motor speed and precision were significantly impaired. Motor speed and precision tests had significant positive correlation with eye signs (r = 0.42) and disability score (r = 0.68). Our results suggest significant cognitive impairment in severely exposed MIC victims.