Schizophrenia is a neurological
disorder that typically strikes when the victim is in their early 20s, but despite its relative prevalence little is
understood about the causes of this debilitating disease. In 25 September
Proceedings of
the National Academy of Sciences, Paul Thompson and colleagues from the University of California at Los Angeles examined the anatomical
progression of the disease in the brain (PNAS 2001, 98:11650-11655).
Thompson et al. used repeated
magnetic resonance imaging (MRI) and brain mapping algorithms to study a number of adolescents with
early-onset schizophrenia. Scans were taken at two-year intervals at three time points to uncover the
dynamics and timing of disease progression.
They found that the earliest deficits occurred in the parietal regions, which underlie visuospatial and
associative thinking and are known to mediate adult deficits through environmental factors. Over five
years, the deficits spread to the temporal lobes, encompassing sensorimotor and dorsolateral prefrontal
cortices, and the frontal eye fields. The patterns of cortical loss correlated closely with the severity
of psychotic symptoms, and were echoed by neuromotor, auditory, visual and frontal executive impairments.
The changes that are seen consistently in
adult studies 
deficits in the dorsolateral prefrontal
cortex and superior temporal gyri were the latest to appear.
Thompson commented: "This is the first study
to visualise how schizophrenia develops in the brain. Scientists have been perplexed about how schizophrenia
progresses and whether there are any physical changes in the brain. It moved across the brain like a forest fire,
destroying more tissue as the disease progressed."
The team suggest the findings could help to spot patients early enough to give treatment. But, there are currently
no drugs that can halt the rapid tissue loss.
SPIS MedWire
(medwire@sciencenow.com)
