Tobacco and Lead Exposures and ADHD

J Gordon Millichap
2010 Pediatric Neurology Briefs  
COMMENT. The authors recommend that children who present with ADHD, OCD, or tic disorder of late onset and in the absence of a family history should be investigated with brain MRI. This report emphasizes the importance of a neurological basis for ADHD and tics, and the need to exclude structural lesions in the cerebrum and connections with the basal ganglia. Children with ADHD of a genetic origin alone develop symptoms early, before 7 years of age. Other structural lesions sometimes associated
more » ... metimes associated with ADHD include temporal lobe arachnoid cyst (Millichap JG, Neurology 1997;48:1435-1439, decreased size of splenium of corpus callosum (Semrud-Clikeman M et al, 1994), and decreased volume of prefrontal cortex, caudate nucleus, and globus pallidum (Castellanos FX et al, 1996). Two children who presented with chorea, athetosis and dystonia were diagnosed with astrocytoma of the thalamus and a pontine midbrain tumor. (Millichap JG, Miller RH, Backus RE, JAMA 1962;179:589-593). Diagnoses of rheumatic chorea, dystonia musculorum deformans, and encephalitis were . entertained before fractional pneumoencephalography defined an expanding lesion. Of 300 intracranial tumors in children treated at the Mayo Clinic between 1950 and 1960, 4 per cent involved the basal ganglia, but less than 1 per cent were associated with involuntary movements. A review of the literature found only 9 similar cases between 1923 and 1961. ATTENTION DEFICIT AND LEARNING DISORDERS TOBACCO AND LEAD EXPOSURES AND ADHD The independent and joint effects of prenatal tobacco and childhood lead exposures on ADHD in a national sample of US children were studied by researchers at Cincinnatti Children'total of 8.7% of children 8 -15 years of age met criteria for ADHD. Prenatal tobacco exposure and third tertile (1.3-5 mcg/dL) current blood lead concentrations were independently associated with ADHD. (Children with lead levels >5mcg/dL were excluded). Compared with children with neither exposure, children with both exposures had an even greater risk of ADHD than if the independent risks were multiplied (p<0.001). Children who attended preschool and boys (vs girls) had increased likelihoods of ADHD. Mexican American and black children had lower risks compared to non-Hispanic white children. (Froehlich TE, Lanphear BP, Auinger P, et al. Association of tobacco and lead exposures with attentiondeficit hyperactivity disorder. ). COMMENT. The association of prenatal tobacco exposure and ADHD has been demonstrated in previous studies, one involving a national data base population, but this is the first indication of a potentiation of effect when combined with childhood low level lead exposure. A similar association with ADHD is reported with a combination tobacco and alcohol prenatal exposure. Patients with ADHD are 2.5 times more likely to be exposed to alcohol in utero and 2.1 times more likely to be exposed to tobacco. Alcohol Pediatric Neurology Briefs 2010
doi:10.15844/pedneurbriefs-24-1-5 fatcat:vsst24kbgbchlkmir3kwn7gdtq