Sylvian Syndrome

At a glance

Syndrome is characterized by pseudobulbar palsy, epilepsy, cognitive deficits, and bilateral perisylvian malformations on imaging.

Synonym

Congenital Bilateral Perisylvian Syndrome.

Incidence

Rare. Recognized following advances in neuroimaging techniques as a distinct syndrome in 1993.

Genetic inheritance

Autosomal recessive; equal male:female ratio.

Pathophysiology

Unknown. Disorder of neuronal migration.

Diagnosis

Suspected by clinical picture and supported by classical MRI findings. These are radiological indications of bilateral perisylvian cortical malformations consistent with polymicrogyria involving the sylvian fissure and opercular cortex.

Clinical aspects

Pseudobulbar palsy, dysarthria, mental retardation and cognitive deficits, and seizures that are atypical and difficult to control by medication. Infantile spasms in the first 6 months of life are often the presenting seizure type. Hypotonia, hemiparesis, and apneas. Pharyngeal and masticatory muscle diplegia, especially tongue. Micrognathia, arthrogryposis.

Precautions before anesthesia

Full assessment of the airway, oromotor function, and degree of pseudobulbar palsy is essential. Preparation for prolonged intubation should be made if appropriate. Seizure type, frequency, and control needs to be reviewed by neurology and optimized. Medication should be continued preoperatively. Assessment of other neurological deficits should be documented. Evidence of acute and chronic effects of aspiration should be looked for and a chest radiograph is performed.

Anesthetic considerations

The potential for gastric regurgitation, recurrent pulmonary aspiration must be considered. Mouth opening and tongue movement are likely to be significantly impaired. Use of an antisialagogue to reduce secretions is helpful preinduction. Induction of anesthesia should be either by spontaneous ventilating inhalational technique or modified rapid sequence induction. Seizures should be considered as a cause of delay in emergence. Extubation should only occur once the child is fully awake; the child may need intubation until fully recovered. Apneas are more frequent postoperatively and appropriate monitoring should be used. The need for sustained mechanical ventilation postoperatively must be considered because of the pseudobulbar palsy.

Pharmacological implications

Avoid drugs that may trigger seizures, such as enflurane and sevoflurane, and consider interactions with antiseizure medication. Caution with opioids if there is a history of apnea.

References