Abstract

Introduction
Holmes tremor (HT) comprises rest, postural and intention tremor subtypes, usually involving both proximal and distal musculature. Perturbations of nigro-striatal pathways might be fundamental in the pathogenesis of HT along with the cerebello-thalamic connections.
Methods
Nine patients with HT phenotype secondary to thalamic stroke were included. Epidemiological, and clinical records were obtained. Structural and functional brain imaging were done with magnetic resonance imaging (MRI) or computed tomography (CT) and positron emission tomography (PET) respectively. Levodopa was administered in sequentially increasing dosage, with various other drugs in case of inadequate response. Longitudinal follow-up was done for at least three months. The essential tremor rating assessment (TETRAS) scale was used for assessment.
Results
The mean latency from stroke to tremor onset was 50.4 ± 30.60 days (range 21-90 days). Dystonia was the most frequently associated hyperkinetic movement (88.8%). Tremor was bilateral in 22.2% of participants. Clinical response was judged based on reduction of TETRAS score by a prefixed value (≥ 30%), pertaining to which 55.5% (n=5) subjects were classified as responders and rest as non-responders. The responders showed improvement with significantly lower doses of levodopa than remaining (240 ± 54.7 mg vs 400 ± 40.8 mg; p=0.012).
Conclusion
Although levodopa is useful in HT, augmenting the dosage of levodopa beyond a certain point might not add to appreciable clinical benefit. Topography of vascular lesions within the thalamus might additionally influence phenomenology of HT.

• Keywords: Dystonia, Holmes tremor, Levodopa, Stroke, Thalamus;