"Through a post-mortem examination, we were able to show that all three patients had a loss of neurons that was typical of that seen in Parkinson's disease. The examination also helped to show that the symptoms of Parkinson's disease were not related to side effects of the medications commonly used to treat schizophrenia," added Dr.Rasmus Kiehl, neuropathologist in UHN's Laboratory Medicine Program, who co-authored the report with CAMH graduate student Nancy Butcher. The team also found that Parkinson's disease in 22q11.2 deletion syndrome is associated with abnormal accumulations of protein called Lewy bodies in the brain in some, but not all cases, just as in another genetic form of Parkinson's disease.
The findings highlight the complexity of clinical care when both Parkinson's disease and 22q11.2 deletion syndrome are present. "Our results may inform best practices in the clinic in these cases," said Dr. Bassett, Senior Scientist in CAMH's Campbell Family Mental Health Research Institute.
Because patients with 22q11.2DS who have schizophrenia are often prescribed anti-psychotic medications, they may experience side-effects such as tremors and muscle stiffness, similar to symptoms of Parkinson's disease.
As a result, the researchers found that anti-psychotic use delayed the diagnosis of Parkinson's disease and the opportunity for treatment by up to 10 years.
For people with early-onset Parkinson's disease, who also have other features that could indicate 22q11.2 deletion syndrome, clinical genetic testing for the deletion on chromosome 22 should be considered, the researchers suggest.
"Our discovery that the 22q11.2 deletion syndrome is associated with Parkinson's disease is very exciting," said Dr. Anthony Lang, Director of the Movement Diso
|Contact: Anita Dubey|
Centre for Addiction and Mental Health