Cerebellar syndromes
Superior cerebellar artery (SCA)
Typical cerebellar/vestibular signs in SCA territory infarcts:
- Vertigo
- Nystagmus
- Ipsilateral limb dysmetria
- Gait ataxia
- Ipsilateral axial lateropulsion
- Vomiting
- Dysarthria
Symptoms and signs attributable to involvement of the brainstem territory of SCA:
- Ipsilateral Horner syndrome
- Contralateral sensory deficit of pain and temperature modalities
- Contralateral trochlear nerve palsy
Additional symptoms and signs may include:
- Ipsilateral loss of emotional expression of the face
- Unilateral or bilateral hearing loss (possibly due to involvement of lateral lemniscus)
- Sleep disorders (due to locus coeruleus involvement)
- Ipsilateral choreiform or athetotic movements or tremor (unusual)
Infarcts involving the entire SCA territory are usually combined with infarcts of the rostral basilar artery territory, and sometimes PICA or AICA territories. Sometimes they occur simultaneously with MCA infarcts.
Anterior inferior cerebellar artery (AICA)
Considered rare but may be underdiagnosed. May herald basilar artery occlusion. Brainstem symptoms/signs are invariably present.
Typical symptoms and signs of AICA territory infarcts:
- Vertigo
- Vomiting
- Tinnitus
- Dysarthria
- Ipsilateral LMN type facial palsy
- Ipsilateral facial sensory deficit (all modalities)
- Hearing loss
- Horner’s syndrome
Additional symptoms may include:
- Ipsilateral conjugate lateral gaze palsy (due to involvement of the flocculus, not the abducens nerve)
- Dysphagia
- Ipsilateral limb weakness (due to involvement of contralateral pyramidal tracts)
Small infarcts involving the root entry zone or nucleus of the vestibular nerve may present with vertigo, nystagmus and pathological vestibuloocular reflex, making them clinically indistinguishable from vestibular neuronitis. This presentation is rare.
Posterior inferior cerebellar artery (PICA)
PICA territory infarcts are by far the most frequent type of cerebellar infarcts.
Most common presentation is lateral medullary syndrome (Wallenberg’s syndrome, see Medullary syndromes section). When the infarct spares the medulla, symptoms and signs may include:
- Vertigo
- Horizontal nystagmus
- Gait ataxia
- Limb ataxia
- Ipsilateral axial lateropulsion
- Falling towards the side of the infarct
- Headache, usually cervical/occipital
- Signs of brainstem compression
As with AICA territory infarctions, small PICA territory infarctions may rarely present as vertigo mimicking vestibular neuronitis.
Border-zone cerebellar infarcts
Uncommon type of small (<2 cm) watershed infarcts usually in the border zone between SCA and PICA or between left and right SCA. Usually secondary to severe occlusive disease of the vertebral or basilar arteries. Their clinical presentation does not differ from territorial infarcts.