Rare form of Alzheimer's disease found in Camelford resident

BMJ Specialty Journals

A rare form of Alzheimer's disease has been discovered in a resident of Camelford, the town in south west England which bore the brunt of the accidental discharge of 20 tonnes of aluminium sulphate into the local water supply almost 20 years ago.

The incident occurred In July 1988, resulting in 20,000 residents across a large area of north Cornwall being exposed to levels of aluminium around 500 to 3000 times the acceptable limit, as defined by the European Union. The incident is the subject of an ongoing government inquiry.

The findings, published ahead of print in the Journal of Neurology Neurosurgery and Psychiatry, concern a woman, who was 44 at the time of the incident.

In May 2003, some 15 years after the incident, the woman, then aged 58, was referred to a neurologist for repeated headaches, difficulties in finding words and doing simple sums, and hallucinations, symptoms she had had for several months. Her condition progressively worsened and she died in April 2004.

A post-mortem examination revealed little out of the ordinary. But her brain revealed a rare form of Alzheimer's disease, known as sporadic early onset beta amyloid angiopathy. Other features typical of Alzheimer's disease were also evident.

No other members of the woman's family had been affected by either Alzheimer's disease or psychiatric problems.

Very high levels of aluminium were also found in the affected areas of her brain tissue, which may have resulted from her abnormally high exposure to aluminium following the incident, say the authors. Aluminium has previously been associated with an increased risk of developing Alzheimer's disease.

However, they emphasise that it is impossible to say whether aluminium caused the disease found in the woman's brain tissue. But they suggest that the survivors of the incident should be tested to see if they have sustained any impairment to their intellectual capacity.

An accompanying editorial by Professor Daniel Perl of Mount Sinai School of Medicine, points out that the association between an increased risk of Alzheimer's disease and exposure to aluminium is somewhat controversial, largely because there are few epidemiological data to support the theory.

Relatively little is known about the exact contribution of environmental factors to the development of Alzheimer's disease, he says, and a single case does not clarify that position.

"However," he writes, "if additional similar cases were to appear among the 20,000 exposed individuals then the implications of this incident would become extremely important. Only time will tell."

He continues: "At the very least, increased efforts towards surveillance of individuals exposed in Camelford is certainly warranted."

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