Cerebellar agenesis with hypoplastic pons (pontocerebellar hypoplasia)
Presentation
Longstanding severe ataxia and hyperreflexia.
Patient Data
Absent cerebellum. Slightly small posterior fossa filled with CSF and contiguous with the fourth ventricle. Hypoplastic pons. Midbrain and medulla are spared.
Normal size and morphology of the corpus callosum. The midline structures including the optic chiasm, nerves and tracts are unremarkable. No abnormal parenchymal signal. Supratentorial ventricular and sulcal pattern is within normal limits.
Case Discussion
Pontocerebellar hypoplasia syndromes is a group of rare genetic conditions with 10 subtypes and resulting in small posterior fossa and hypoplastic cerebellum and pons. Complete cerebellar agenesis is extremely rare.