Holmes tremor following thalamic hemorrhagic stroke

Background

Holmes tremor (HT) is a rare movement disorder characterized by low-frequency (<4.5 Hz) tremors affecting the upper limbs, exacerbated by posture and voluntary movements. It typically arises from lesions to the brainstem, cerebellum, or thalamus, with stroke being a common etiology. The tremor usually emerges weeks to months after the initial insult due to aberrant neural pathway reorganization.

Case presentation

A 67-year-old man with hypertension presented with Right-sided numbness and dysarthria from a left thalamic hemorrhagic stroke with intraventricular extension. Ten days post-discharge, he developed a low-frequency (3–4 Hz) left arm tremor with rest, postural, and kinetic components. Neurological examination revealed mild dysmetria without bradykinesia or rigidity. Treatment with trihexyphenidyl and gabapentin provided minimal benefit, while levodopa 100 mg three times daily yielded substantial improvement in limb control. The delayed onset, tremor characteristics, and localization to the thalamus supported the diagnosis of Holmes tremor.

Discussion

This case highlights the complex pathophysiology of HT involving disruption of cerebello-thalamo-cortical and dentato-rubro-olivary pathways. The rarity of HT (2–4 % of all tremor cases) and its variable response to pharmacotherapy underscore the need for multidisciplinary management. Current literature supports levodopa as a primary treatment option, with response rates exceeding 50 % in some studies. This patient's positive response to levodopa further confirms dopaminergic pathway involvement in the pathophysiology. For refractory cases, deep brain stimulation (DBS) targeting the ventral intermediate nucleus of the thalamus can be considered, with recent evidence suggesting superior tremor suppression compared to pharmacotherapy alone. This case emphasizes the importance of recognizing HT and its manifestations for proper diagnosis and management.