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Cutaneous vasomotor reflexes (CVR), the transient waves of cutaneous vasoconstriction after stimuli, such as a cough, were recorded from the digits of patients with unilateral frontoparietal lesions using a laser doppler flowmeter. Vasoconstriction was 6-15 times greater on the fingers contralateral to the lesions, an effect which was independent of the temperature difference between limbs. CVRs may be tonically inhibited under normal circumstances by control from the cerebral hemispheres.

Assessment of stability and tremor in the fingers in patients with unilateral frontoparietal lesions involved the task of attempting to keep the finger still on a typewriter key connected to a strain gauge. In patients with no or minimal pyramidal motor signs and/or cortical sensory signs, the amplitudes of tremor compared with normal controls showed that the contralateral side was not significantly different from normal but that the ipsilateral side was significantly less stable than normal. In normal subjects the tremor seen during the task, and determined from the fast Fourier transform, (FFT), showed a peak at 1-3Hz and a gradual falling off to background levels by 6Hz or so. In patients with spasticity, weakness and sensory impairment there was an additional peak of tremor seen at 6-7Hz ipsilateral to the cerebral lesion.

Stability and tremor in the fingers were assessed by a new technique in patients with unilateral cerebellar syndromes. In 11 patients with unilateral cerebellar hemisphere lesions tremor was observed with either clear tremor at 5-7 Hz or prolongation of the tremor profile out to 11 Hz. In 10 patients with unilateral cerebellar lesions associated with ipsilateral past-pointing there was an asymmetry in finger stability. Compared with normal subjects there was a significant decrease in stability contralateral to the lesion, while the ipsilateral side's stability was not different from normal. In patients with high brain stem lesions at the level of cranial nerves VII and above, tremor had frequencies of 5-7 Hz. In those with lower brain stem lesions, often with long tract signs as well, the frequencies of tremor were faster, 8-11 Hz, which may reflect damage to cerebellar inflow tracts. A broad if not specific correlation was found between clinical condition, site of lesion and finger stability and tremor.