Intention tremor

Mô tả: Intention tremor is a slow (2- to 4-Hz) tremor during voluntary movement that develops as the limb approaches the target.41,68 Tests to assess target seeking, such as the finger-to-nose test and heel-to- shin test, are performed to detect intention tremor.68 RELEVANT NEUROANATOMY AND TOPOGRAPHICAL ANATOMY

Nguyên nhân: Common • Cerebellar infarction • Cerebellar haemorrhage • Alcohol misuse • Drugs (e.g. benzodiazepines, lithium, phenytoin) • Multiple sclerosis Less common • Hereditary cerebellar degeneration (e.g. Freidreich’s ataxia) • Mass lesion (e.g. tumour, abscess, AVM) • HSV cerebellitis • Paraneoplastic cerebellar degeneration

Cơ chế: Intention tremor is an ipsilateral hemispheric cerebellar sign. Lesions of the intermediate and lateral cerebellar hemispheres may cause slow, uncoordinated and clumsy movements of the ipsilateral distal extremity that are aggravated during attempted target localisation tasks (see Table 5.22).4 The To medial descending systems To lateral descending systems Motor execution To motor and premotor cortices Balance and eye movements To vestibular nuclei Motor planning Spinocerebellum Cerebrocerebellum Vestibulocerebellum

Ý nghĩa lâm sàng: Intention tremor is an ipsilateral hemispheric cerebellar sign. In two studies of patients with unilateral cerebellar lesions, intention tremor was present in 29%.4,29,30