Positron emission tomographic scans of patients with
TTM show increased metabolic activity in the cerebellar and
parietal cortex,11 while magnetic resonance imaging studies
have found decreased volume in the left side of the putamen.12
These studies, though fascinating in that they document biologic
differences between patients with TTM and healthy control
subjects, are not useful for diagnosing TTM, nor do they
assist in developing an effective treatment strategy.