Cerebellar Hypoplasia

At a glance

A congenital defect of the cerebellum presenting with neurologic features.

Incidence

Unknown, but very rare.

Genetic inheritance

Most often autosomal recessive, but X-linked forms of congenital cerebellar hypoplasia with the genetic defect located on chromosome Xp11.21-q24 and mutations in the oligophrenin-1 gene (OPHN1) have also been described.

Diagnosis

Based on the clinical findings and confirmed by MRI- or CT scanning of the brain. These children may get misdiagnosed as having spastic or choreoathetoid cerebral palsy secondary to a perinatal insult.

Clinical aspects

Cerebellar developmental defects can occur as isolated defects or more commonly in combination with other nervous system defects like cortical hypoplasia and corpus callosum agenesis. With isolated complete cerebellar aplasia, infants present at birth with hypotonia, tremor and nystagmus. Central respiratory depression has been described. Less severe forms may manifest as varying degrees of mental retardation, delayed motor development, para- or quadriparesis, hypo- or areflexia, nonprogressive truncal and gait ataxia, tremor, truncal titubation, bilateral, alternating esotropias, nystagmus, tongue dysmetria, and speech disorders (dysarthria). Recent research also points to an extended spectrum of apparent cerebellar functions including modulation of cognitive processes and associates cerebellar hypoplasia and Purkinje neuron hypocellularity with autistic spectrum disorder.

Precautions before anesthesia

Evaluate respiratory function (clinically, history, chest x-ray or CT, pulmonary function tests and arterial blood gas analysis). Developmental delay may cause agitation and stress in the perioperative period, thus anxiolytic and sedative premedication and/or presence of a parent (or primary caregiver) for induction of anesthesia may be beneficial. However, potentially increased sensitivity to these types of drugs may require dose-adjustment and close monitoring of vital signs.

Anesthetic considerations

Anesthesia care in autosomal recessive cerebellar hypoplasia has not been described. In ☞Joubert Syndrome, of which cerebellar hypoplasia has been a component, an increased sensitivity to respiratory depressants has been reported, thus prolonged postoperative respiratory monitoring is recommended.

Pharmacological implications

None specific to this disorder, other than the aforementioned potentially increased sensitivity to opiates and other respiratory depressants.

Other condition to be considered

• ☞Joubert Syndrome (Joubert-Boltshauser Syndrome; Cerebellar Vermis Agenesis Syndrome; Cerebello-parenchymal Disorder Type IV; Chorioretinal Coloboma with Cerebellar Vermis Aplasia; Coloboma, Chorioretinal with Cerebellar Vermis Aplasia): Genetic disorder characterized by cerebral malformations (vermis and brainstem) resulting in severe coordination (ataxia) and breathing (sleep apnea, hyperpnea) disorders.

References