Thalamic versus midbrain tremor; two distinct types of Holmes' Tremor: a review of 17 cases

Introduction Holmes Tremor (HT) is a unique and debilitating movement disorder. It usually results from lesions of the midbrain and its connection but can also result from posterior thalamic injury. Clinical examination can help lesion localization between these two areas. We studied the clinical features and their radiological correlations to distinguish midbrain HT (HT-m) from thalamic HT (HT-t). Methods Retrospective review of 17 patients with a HT-type presentation was conducted. Tremor characteristics, associated clinical signs and radiological findings were studied. Results Eleven patients had a myorythmic rest tremor, large amplitude proximal tremor with goal-directed worsening, with or without mild distal dystonic posturing, representing HT-m. Six patients had slow, large amplitude proximal tremors and distal choreathetoid movements, significant proximal/distal dystonic posturing, associated with proprioceptive sensory loss, representing HT-t. Haemorrhagic lesions were the predominant cause of HT-m; whereas, ischaemia was more commonly associated with HT-t. Conclusion When assessing patients with HT, attentiveness to the presence of associated signs in the affected limb, such as a proprioceptive sensory deficits and additional movement disorders, can aid lesion localisation, which can have implications for management.

Automated summary

Holmes Tremor (HT) is a unique and debilitating movement disorder that can result from midbrain or thalamic lesions. Clinical examination can aid in localization, with HT-m characterized by different tremor features compared to HT-t. Lesion localization can have implications for management strategies.