bilateral parasagittal parieto-occipital polymicrogyria

Bilateral parasagittal parieto-occipital polymicrogyria is a neurological condition characterized by an abnormal development of the brain’s cerebral cortex, particularly affecting the parieto-occipital regions. The condition is associated with a characteristic pattern of polymicrogyria, where excessive, small, and irregular brain folds are observed. Variants in the FIG4 gene have been implicated, and the condition is inherited in an autosomal recessive manner. Although precise prevalence data is not available, symptoms often prompt clinical investigation during early childhood.

Individuals with this condition typically present with a range of neurological features. Consistently observed signs include visual hallucinations, focal impaired awareness seizures, ventriculomegaly, and the defining abnormal cortical pattern of polymicrogyria, which is noted on neuroimaging. Many patients also experience bilateral tonic-clonic seizures with a focal onset, while a subset may have episodes of status epilepticus, aggressive behavior, delirium, or even sudden unexpected death in epilepsy. Not all individuals experience all features, and severity varies considerably.

This condition is caused by pathogenic variants in the FIG4 gene and is inherited in an autosomal recessive pattern. In autosomal recessive conditions, an affected individual inherits two altered copies of the gene, one from each parent who are typically asymptomatic carriers. FIG4 has a role in cellular signaling and maintenance, and its disruption is associated with abnormal brain development. Families are encouraged to consider genetic counseling to understand the implications and recurrence risks associated with this inheritance pattern.

Currently, management focuses on supportive care and symptom management, with treatment strategies tailored to the individual’s needs. A multidisciplinary team is typically involved in addressing seizure control and managing other neurological symptoms, and supportive therapies are central to care. Genetic counseling is recommended for families to better understand the inheritance and potential implications for future family planning. Patients should discuss treatment options with their healthcare team to determine which interventions may be most appropriate for their situation.

Outcomes for individuals with this condition are variable and depend on the severity of symptoms, age at diagnosis, and access to specialized care. The condition may progress, stabilize, or follow a variable course, with some individuals experiencing significant challenges related to seizures and other neurological features while others may achieve relative stability. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists and genetic counselors to obtain tailored guidance and support.