Background: Limb ataxia is classically attributed to cerebellar hemispheric lesions, although isolated lesions of the inferior cerebellar peduncle (ICP) in the medulla may also cause this sign. It is still unclear why only some patients with acute cerebellar infarcts in the posterior inferior cerebellar artery (PICA) territory present with limb ataxia. The proximal intracranial posterior circulation (P-PC) territory includes structures fed by the intracranial vertebral arteries (ICVAs): the medulla, supplied by small ICVAs branches, and posterior inferior portion of the cerebellum, fed by PICA. ICP and PICA territory cerebellar infarcts most often occur independently but occasionally occur together.
Objective: To identify structures responsible for limb ataxia in acute P-PC brain infarcts correlating clinical and topographical findings.
Methods: Sixteen patients (8 women) were included with ages ranging from 30 to 82 years (mean age, 62 years) with isolated acute strokes in the P-PC territory.
Results: The cases reported here indicate that limb ataxia in acute P-PC territory infarcts may be associated with a damage to the ICP in the dorsolateral medulla, regardless of a hemispheric cerebellar lesion. In fact among the 9 patients with PICA stroke, limb ataxia was observed only in the 2 patients who also presented a damage to the dorsolateral medulla involving the ICP. Of the 7 patients with isolated dorsolateral medullary infarct, only 5 patients with an ICP damage had limb ataxia.
Conclusions: When correlating limb ataxia and acute P-PC infarcts it is important to take in account the entire ICVA territory.
- limb ataxia
- posterior inferior cerebellar artery
- intracranial vertebral artery
- inferior cerebellar peduncle