Neurological and cognitive recovery following abstinence from petrol sniffing.

Anecdotal observations suggest that neurological impairments associated with petrol (gasoline) sniffing resolve with abstinence, although these effects have not been proven empirically. Severe exposure to leaded petrol may induce a lead encephalopathy that extends beyond any acute intoxication and requires emergency hospital treatment. Previously, in chronic petrol sniffers, we showed neurological, saccadic, and cognitive abnormalities that were more severe in petrol sniffers with a history of hospitalization for lead encephalopathy, and that correlated with blood lead levels and the length of time of sniffing petrol. Ex-petrol sniffers showed a qualitatively similar but quantitatively less severe pattern of impairment. Petrol sniffing was stopped completely in one of the study communities by modifying social, occupational, and recreational opportunities. After 2 years, we obtained biochemical and neurobehavioral (neurological, saccade, and cognitive) data from all available participants of the earlier study including 10 nonsniffers and 29 chronic petrol sniffers, with six of these individuals previously receiving hospital treatment for lead encephalopathy. Here, we report that blood lead was reduced and that neurobehavioral impairments improved, and in many cases normalized completely. The most severe petrol-related neurobehavioral impairment was observed among individuals who had longer histories of abuse and higher blood lead levels, and among petrol sniffers with a history of lead encephalopathy. Those with the greatest extent of neurobehavioral impairment showed the greatest degree of improvement with abstinence, but were less likely to recover completely. This is the first direct evidence that neurological and cognitive impairment from chronic petrol sniffing ameliorates with abstinence and may recover completely.

Neurological and cognitive impairment associated with leaded gasoline encephalopathy.

BACKGROUND: A toxic encephalopathy (or 'lead encephalopathy') may arise from leaded gasoline abuse that is characterised by tremor, hallucinations, nystagmus, ataxia, seizures and death. This syndrome requires emergency and intensive hospital treatment. METHODS: We compared neurological and cognitive function between chronic gasoline abusers with (n=15) and without (n=15) a history of leaded gasoline encephalopathy, and with controls who had never abused gasoline (n=15). RESULTS: Both groups of chronic gasoline abusers had abused gasoline for the same length of time and compared to controls, showed equivalently elevated blood lead levels and cognitive abnormalities in the areas of visuo-spatial attention, recognition memory and paired associate learning. However, where gasoline abusers with no history of leaded gasoline encephalopathy showed only mild movement abnormalities, gasoline abusers with a history of leaded gasoline encephalopathy showed severe neurological impairment that manifest as higher rates of gait ataxia, abnormal rapid finger tapping, finger to nose movements, dysdiadochokinesia and heel to knee movements, increased deep tendon reflexes and presence of a palmomental reflex. CONCLUSIONS: While neurological and cognitive functions are disrupted by chronic gasoline abuse, leaded gasoline encephalopathy is associated with additional and long-lasting damage to cortical and cerebellar functions.

A study of the use of free nicotine patches by Indigenous people.

OBJECTIVE: To assess use of free nicotine patches by Indigenous people when offered a brief intervention for smoking cessation, and to assess changes in smoking behaviour at six months. METHODS: We conducted a pre and post study in three Indigenous communities in the Northern Territory. RESULTS: Forty Indigenous smokers self-selected to receive free nicotine patches and a brief intervention for smoking cessation, and 71 chose the brief intervention only. Eighty-four per cent of participants were followed up; 14% of participants could not be located. Fifteen per cent of the nicotine patches group (10% with CO validation) and 1% (CO validated) of the brief intervention only group reported that they had quit at six months. Seventy-six per cent of the nicotine patches group and 51% of the brief intervention only group had reduced their consumption of tobacco. No participant completed a full course of patches. One possible side effect--the experience of bad dreams--was attributed in one community to the person concerned having been 'sung' or cursed. CONCLUSIONS: Free nicotine patches might benefit a small number of Indigenous smokers. Cessation rates for the use of both nicotine patches and brief intervention alone were lower than those in other populations, possibly because the study was conducted in a primary care setting and because of barriers to cessation such as widespread use of tobacco in these communities and the perception of tobacco use as non-problematic.

Validity and utility of community health workers' estimation of kava use.

OBJECTIVE: Estimating illicit substance use in epidemiological studies is challenging, particularly across ethical, cultural and language barriers. While developing the methods for a case-control study of the effects of heavy kava consumption among Aboriginal people in remote Northern Territory (NT), we examined the validity and utility of alternative methods for estimating exposure. METHODS: We assessed the level of agreement between a consensus of Aboriginal health workers in two different communities using interviews conducted with community members and health workers and individuals' self-reported kava consumption. Exposure measures included history of kava use, current kava use and history of heavy use. Agreement between a health worker consensus classification and individuals' self-report was analysed and agreement among several health workers in a consensus classification without self-report was assessed. RESULTS: Health workers concurred about an individual's history of kava use (k=0.83), current use (k=0.43) and also level of use (k=0.33). There was very good agreement between health workers' consensus and self-reported history of use (k=0.77). Agreement among health workers about current kava use was poor (k=0.08), while there was fair agreement between health workers and self-reported heavy kava users (k=0.36). Data from review of clinic patient notes supported agreement between consensus classification and self-reported history and level of use (k=0.39). CONCLUSIONS: Self-reported kava use may be a poor estimate of current use especially when obtained from interviews away from a confidential clinic setting. Consensus classification by knowledgeable Aboriginal health workers provided comprehensive coverage, efficiently and with greater reliability and assisted to identify 'excessive' kava use.