Ataxia is the cardinal sign of cerebellar dysfunction and when it occurs, it indicates the possibility of cerebellar lesions. However, this may not always be the correct explanation. Appenzeller and Hanson reviewed studies, published between 1916 and 1953, of patients with cerebellar signs attributed to parietal lesions. Extensive lesions within the parietal lobes and sensory changes were common in these patients. They also reported on an adult who presented with pain and weakness of the left arm, lasting for 2 hours. When examined 2 weeks later, the limb was severely ataxic, but with no detectable weakness or sensory deficit. In addition, the patient had a dressing apraxia. At autopsy a small infarct in the arm area of the right postcentral gyrus was observed. The cerebellum and brainstem were normal.