Disproportionate enlargement of the occipital horns of the lateral ventricles in association with partial or complete agenesis of the corpus callosum.
First described in 1946 by the Russian neuroanatomist Paul Ivan Yakovlev (1894-1983) and Richard C. Wadsworth, an American pathologist.
Some cases are thought to be X-linked or autosomal dominant inherited with incomplete penetrance. Colpocephaly has been associated with mosaicism of trisomy 8 and trisomy 9, Toxoplasma gondii infection during pregnancy, and maternal ingestion of ethanol, oral contraceptives, and other medications during pregnancy.
The main feature is an enlargement of the occipital horns of the lateral ventricles with partial or complete agenesis of the corpus callosum. Normally, the densely packed axons of the corpus callosum help stabilize the lateral ventricles. In partial or complete agenesis of the corpus callosum, this support for the lateral ventricles is missing, particularly in the posterior areas, where enlargement of the dorsal horns is characteristic. This finding is pronounced if the cingulum is hypoplastic or aplastic, which is typically the case in colpocephaly. Common symptoms may include mental retardation, learning disabilities, seizures, and motor and visual abnormalities. It may be associated with other anomalies, such as microcephaly, micrognathia, lissencephaly, cerebellar atrophy, pachygyria, microgyria or macrogyria, ☞Pierre Robin Syndrome, ☞Neurofibromatosis, optic nerve hypoplasia, chorioretinal coloboma, cleft palate, and myelomeningocele.
Precautions before anesthesia
Inquire about seizure treatment and its efficacy. Anticonvulsant therapy should be continued until the morning of surgery and resumed as soon as possible postoperatively and given intravenously if oral intake is not possible. 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.
Considerations should mainly focus on associated disorders, because colpocephaly per se should not significantly affect the anesthetic management. The main concern is airway management if colpocephaly is associated with ☞Pierre Robin Sequence. In these cases, maintaining spontaneous ventilation is recommended until the airway has been secured. Alternative airway management options should be immediately available (eg, supraglottic airway device, fiberoptic bronchoscope) and adherence to an established difficult airway algorithm is advised. A surgeon familiar with surgical airway management and the necessary equipment should easily be available in the operating room. Alternatively, an awake fiberoptic intubation should be considered.
Avoid epileptogenic drugs (eg, meperidine/pethidine) or drugs that decrease the seizure threshold in patients with seizures. Chronic anti-seizure treatment may interfere with the metabolism and elimination of other drugs that share the same metabolic pathways.