Postural sway analysis of a teenager with childhood lead intoxication--a case study

We had an opportunity to study a 15-year-old boy, evaluating the long-term effect of early childhood lead (Pb) poisoning on the maturation of postural balance. Postural balance (or sway) was quantified using a microprocessor-based Force Platform System along with four postural tasks specifically designed to indirectly challenge and/or minimize the effect of vision, proprioception and vestibular systems relevant for postural stability. The Pb-intoxicated patient showed increased postural sway compared to those of non-poisoned young adults and a 14-year-old boy for postural tasks requiring input from higher centers. A review of historical information and results of the physical and neurological examinations did not reveal an alternative explanation for this patient's postural sway abnormalities. These responses are also comparable to those noted in younger children with chronic Pb-exposure histories. In summary, this case study gives suggestive evidence that early excessive exposure to Pb can have long-term, detrimental neurological effects as reflected by postural stability. Measurement of postural balance appears to be a sensitive research methodology to assess subclinical neurological effects of remote lead intoxication.