Cerebellar agenesis and diabetes insipidus

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.

Morphological spectrum of prenatal cerebellar disruptions

There is increasing evidence that the cerebellum is susceptible to both prenatal infections and haemorrhages as well as being vulnerable in extremely preterm babies, but not to perinatal and postnatal hypoxic-ischaemic injuries. Starting with the imaging appearance we describe and illustrate a spectrum of prenatal cerebellar disruptions: cerebellar agenesis; unilateral cerebellar hypoplasia; unilateral cerebellar cleft; global cerebellar hypoplasia; vanishing cerebellum in myelomeningocele; and disruption of cerebellar development in preterm infants. We discuss neuroradiological characteristics, possible disruptive events, and clinical findings in the different morphological patterns. Remarkably, the same disruptive agent can cause different neuroradiological patterns, which appear likely to represent a morphological spectrum. The analysis of imaging patterns is crucial in recognising cerebellar disruptions. Recognition of cerebellar disruptions and their differentiation from cerebellar malformations is important in terms of diagnosis, prognosis, and genetic counselling.

MR demonstration of complete cerebellar and corpus callosum agenesis

Complete cerebellar agenesis is a very rare entity, which occurs during the early period of embryogenesis and is usually associated with severe motor dysfunction. We report a case of complete cerebellar agenesis with complete corpus callosum agenesis diagnosed on magnetic resonance imaging (MRI). These anomalies were also associated with rudimentary pons.