May 16, 2009 — Magnetization Transfer
Imaging, MTI, has been used to visualize previously unknown alterations
in the cerebral architecture of patients with Tourette’s syndrome. The
researchers also found a correlation between the extent of some of the
structural changes and symptom severity.
Kirsten Müller-Vahl, from Hanover Medical School, led a team of
researchers who used normal MRI scanning and the new MTI technique to
investigate the brains of 19 Tourette’s patients and 20 controls. They
identified alterations in the frontal lobe of the Tourette’s group that
they suggest may be responsible for the pathology of the syndrome.
Müller-Vahl said, "Our in vivo findings, using two sensitive and
unbiased techniques, support the hypothesis that alterations in
frontostriatal circuitries underlie Tourette’s pathology".
The MTI technique used by the researchers has never before been
applied to the study of Tourette’s. It is a refinement of the nuclear
magnetic resonance technique and allows for the detection of changes
invisible to conventional MRI scanners. Tissue alterations in
comparison to controls were detected in brain areas involved in the
selection, programming, initiation, and control of movement. The
authors conclude, "We suggest that Tourette’s is primarily caused by a
dysfunction in prefrontal cortex areas rather than the basal ganglia,
as has been previously thought".
Tourette’s syndrome is estimated to affect between 1-10 children per
1000 and, although the severity of a person’s tics tends to decline
with age, as many as 1% of the adult population may have some form of
tic disorder. Symptoms include various facial, phonic and other motor
tics – the well-known propensity for ‘un-voluntary’ swearing is in fact
relatively uncommon, only affecting about 10% of Tourette’s patients.
Source : BMC Neuroscience