NEUROLOGICAL AND COGNITIVE ABNORMALITIES ASSOCIATED WITH CHRONIC PETROL SNIFFING

Substance abuse through the deliberate inhalation of petrol (petrol sn iffing or gasoline sniffing) is prevalent in inner-urban and remote ru ral communities. Although acute toxic encephalopathy is a well-documen ted consequence of petrol sniffing, the neurological and cognitive eff ects of chronic petrol sniffing are unknown. A structured neurological examination and the Cambridge Neuropsychological Test Automated Batte ry (CANTAB) were used to assess neurological and cognitive function in 33 current-sniffers (individuals who had sniffed petrol for >6 months ), 30 ex-sniffers (individuals who had sniffed petrol in the past but had abstained for 6 months) and 34 matched non-sniffers (individuals w ho had never sniffed petrol), No subject was, or had been, encephalopa thic from petrol sniffing and all were residing in their community, Bl ood lead and hydrocarbon levels and information about petrol sniffing behaviour were obtained from each subject, When compared with non-snif fers, current-sniffers showed higher rates of abnormal tandem gait, ra pid alternating hand movements, finger to nose movements, postural tre mor, bilateral palmomental reflexes and brisk deep reflexes. Cognitive deficits occurred in the areas of visual attention, visual recognitio n memory and visual paired associate learning, Ex-petrol sniffers show ed higher rates of abnormal tandem gait and bilateral palmomental refl exes and cognitive deficits in the areas of visual recognition memory and pattern-location paired associate learning. Blood lead levels and length of time of petrol sniffing correlated significantly with the ma gnitude of neurological and cognitive deficits. Blood hydrocarbon leve ls were not related to neurocognitive deficits, although this may have been due to methodological difficulties in obtaining hydrocarbon leve ls, These results suggest that subtle neurological and cognitive abnor malities do occur in individuals who abuse petrol but who do not have acute toxic encephalopathy and that the severity of these abnormalitie s is reduced with abstinence.