OBJECTIVE: 3 Hz postural tremor was described in patients with anterior cerebellar lobe atrophy, however sensitivity and specificity of this sign in degenerative cerebellar diseases has not yet been evaluated. Our aim was to assess the 3 Hz tremor in patients with cerebellar ataxia, compare its sensitivity and specificity with other posturography parameters and to find out a correlation of intensity of 3 Hz tremor with ataxia severity.
METHODS: 30 patients with degenerative cerebellar ataxia, a control group of 30 patients with compensated peripheral vestibulopathy and 40 healthy volunteers were examined by posturography. 3 Hz tremor was assessed both qualitatively and quantitatively, its sensitivity and specificity were compared with other standard posturography parameters. RESULTS: 3 Hz postural tremor was detected in 90% of patients with cerebellar ataxia, with 100% specificity and 90% sensitivity.
The sensitivity and specificity of quantitative analysis of 3 Hz tremor was largely superior to standard posturography parameters when differentiating patients with cerebellar ataxia from vestibular impairment and healthy controls. CONCLUSION: 3 Hz postural tremor is highly sensitive and specific sign of cerebellar impairment in patients with cerebellar ataxia.
SIGNIFICANCE: Evaluation of 3 Hz postural tremor should be a standard part of posturography examination when considering a cerebellar impairment.