Adult lead encephalopathy

Abstract

The neurotoxicity of lead to the adult brain is less well-known than that seen in children. It may present as acute severe encephalopathy or as chronic cognitive and behavioural symptoms, either in isolation or with systemic features of lead intoxication. Magnetic resonance imaging findings in lead encephalopathy vary. The pathogenesis of lead encephalopathy and its effects on cognition both during development and in the adult are discussed. That encephalopathic symptoms do not correlate with blood lead levels and that they may persist after chelation are highlighted. As an illustration, we describe a patient with chronic cumulative lead intoxication, who presented with peripheral neuropathy, anaemia, and a 'lead line' on the gingiva. She had cognitive dysfunction with extensive subcortical and cerebellar white matter lesions on magnetic resonance imaging. An area of restricted diffusion in both frontal regions is likely to be due to active ongoing demyelinating at the 'leading edge' of the lesion. Although systemic features and the peripheral neuropathy improved with chelation, the encephalopathy showed only marginal change, with later appearance of a symmetric akinetic-rigid state.

Evaluation of the levels of selected heavy metals in leafy vegetables from irrigation farming sites in Jos, Plateau, Nigeria

“…Lead is thought to undermine the normal synaptic pruning process in young brains, likely underlying the cognitive and behavioral changes seen in young children with excessive lead exposure (Souza et al, 2013). Peripheral neuropathy is a common manifestation of chronic lead toxicity in adults.…”

“…Peripheral neuropathy is a common manifestation of chronic lead toxicity in adults. The most severe neurologic manifestations of lead toxicity such as seizures and coma occur in acute lead encephalopathy, which is thought to be at least in part secondary to leadinduced cerebral microvascular changes leading to cerebral edema and resultant increased intracranial pressure (Souza et al, 2013). Lead causes anemia by being a potent inhibitor of multi-enzyme activities involved in heme synthesis as well as enzymes involved in maintaining erythrocyte cell membrane integrity, which leads to decreased production and increased destruction of erythrocytes, respectively (Lidsky and Schneider, 2003).…”

Functional consequences of lead and mercury exposomes in the heart

“…In severe cases of acute encephalopathy caused by lead poisoning, seizures and coma can be observed, even in adults, due to damage of the cerebral microvasculature, edema, and an increase in intracranial pressure (de Souza et al, 2013). In adults, peripheral neuropathy is more frequently observed, although the underlying mechanisms are poorly understood (Thomson and Parry, 2006).…”

Investigation and monitoring of heavy metal poisoning

“…However, if the source of exposure has not been recognised, the diagnosis of lead poisoning may go undiscovered until an individual presents with symptoms or signs of poisoning 4. These include abdominal pain, constipation, headache, poor concentration, anaemia and less commonly, a peripheral or motor neuropathy and/or confusion/encephalopathy 4–7. The non-specific nature of some of these complaints means that unless a judicious history is taken, individuals may undergo a number of other, often invasive, investigations before a blood lead concentration is requested.…”