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At a glance

This is a rare neurologic syndrome characterized by mental retardation, epilepsy, and enlarged gyri (pachygyria). Other features include cognitive abnormalities, and a peculiar inability to use the mouth and tongue muscles.


Pachygyria Mental Retardation Epilepsy; Perisylvian Polymicrogyria Syndrome.


This medical condition was originally described in 1991 by Dr Ruben Kuzniecky, a professor of neurology at New York University, specializing in epilepsy, epilepsy surgery, and neuroimaging.


Two brothers have been described with this disease.

Genetic inheritance

It is presumed autosomal recessive inheritance. Normal chromosomal studies have been reported.

Clinical aspects

Severe nonprogressive encephalopathy characterized by impairment of motor and intellectual development with atypical, absence, and generalized tonic-clonic seizures. The parietal cortex was enlarged to 10 to 12 mm on MRI, which suggested pachygyria (enlarged gyri).

Anesthetic considerations

Type, severity, and control of seizure disorder should be evaluated. Antiepileptics should be continued throughout the perioperative period. Some antiseizure medications affect the pharmacodynamic properties of some commonly used anesthetic drugs (eg, phenytoin increases the requirements for nondepolarizing muscle relaxants).

Other conditions to be considered

  • Congenital Bilateral Perisylvian Syndrome (CBPS): This disorder is characterized by diplegia of the face, tongue, jaws, pseudobulbar palsy, dysarthria, inability to chew, dysphagia, and epilepsy. In most cases, mild-to-severe mental retardation is present. The clinical picture is influenced by the age of onset. CBPS is a late migration disorder of the brain, which is recognizable by MRI brain and should be suspected clinically in any infant or child presenting with oromotor dysfunction, pseudobulbar signs, developmental delay, and seizures. Although it can be present at birth, it also may appear later during childhood. The clinical presentation of epilepsy is variable, ie, atypical absence seizures, atonic-tonic seizures, tonic-clonic seizures, that becomes apparent between 2 and 12 years of age. It is believed to affect both sex equally. It is thought to result from neuronal dysmigration in the cortex. Three types have been suggested: congenital, infantile, and childhood form. The disorder appears to occur sporadically. Histopathologically, polymicrogyria with cortical thickness of 5 to 7 mm can be demonstrated.

  • Double Cortex Syndrome (Subcortical Band Heterotopia Syndrome): Clinically similar to the Kanievsky Syndrome (often considered a variant), it is nevertheless differentiated by the presence of a band of subcortical heterotopic gray matter underlying the cortical mantle. The clinical features seem to vary from case to case, depending upon the area of the cerebral cortex involved in the neuronal process. Various forms of epilepsy manifestation, ie, atypical absence seizures, atonic-tonic seizures, tonic-clonic seizures, can be observed. It is also accompanied with mild-to-moderate intellectual disability. Some researchers believe that the development of the cerebral cortex during ...

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