MR demonstration of complete cerebellar and corpus callosum agenesis

Total cerebellar agenesis: A case report of a very rare condition

Complete cerebellar agenesis is an extremely rare condition characterized by the complete absence of cerebellar tissue. Only a small number of cases have been reported, with varying motor and cognitive deficits. We describe a case of an 11-month-old baby with developmental delay, whose CT scan evaluation showed the complete absence of the cerebellum with no other associated cerebral malformation.

Clinical and MRI findings of cerebellar agenesis in two living adult patients

Cerebellar agenesis (CA) is an extremely rare entity. We present two adult patients with CA. The 61-year-old man had ataxia, dysarthria, abnormalities in cerebellar tests, severe cognitive impairment, and moderate mental retardation. The 26-year-old woman had dysmetria, dysdiadochokinesia, and dysarthria as well as mild cognitive impairment and mild mental retardation. Magnetic resonance imaging (MRI) showed complete absence of the cerebellum with small residual vermis. Brainstem was hypoplastic and structures above tentorium were normal. Supratentorial white matter bundles were unaffected in diffusion tensor tractography. Only few adult patients with CA have so far been published. These cases show that patients with CA present with a variety of developmental, clinical, and mental abnormalities; and emphasize the role of the cerebellum in normal motor, language, and mental development.

Preservation of language in the ataxic infant in a case of cerebellar agenesis

An eight-month-old male Caucasian infant presented with ataxia and titubations, which had been noticed shortly after birth. He was born to healthy non-consanguineous parents after an unremarkable pregnancy. There was no maternal use of drugs, alcohol or tobacco. A prenatal ultrasound at 36 weeks conceptual age (performed at the request of the parents since the 20 week ultrasound had not been performed) revealed an enlarged posterior fossa, no cerebellar tissue, a normal corpus callosum and no evidence of hydrocephalus. He was delivered via spontaneous vaginal delivery at 37 weeks gestation without complications. Birth weight was 3630g and the neonatal course was unremarkable. Developmentally, at eight months-of-age he could not sit. A formal developmental assessment at 19 months-of-age revealed gross and fine motor delay. He was pulling to stand and was cruising but was not walking independently. He was able to stack two cubes. He was very social, highly imitative and used over 50 words. His words were clear and there was no dysarthria. His receptive and expressive language skills were deemed to be at the 18-21 month level. Family history was non-contributory. Physical examination at 19 months-of-age revealed weight and height between the 10-25 percentiles and head circumference at the 25th percentile. Head titubation was present throughout the examination. Extraocular movements were full, with bilateral intermittent esotropia. Upon fixing of the head, horizontal nystagmus and saccadic intrusions on smooth pursuit exam were noted. Fundoscopic examination was normal. He had mild truncal hypotonia, with appropriate strength for his age.