Purpose: To correlate clinical outcome with the size and location of clefts in patients with schizencephaly.
Patients and methods: MR scans and clinical records of 20 patients with schizencephaly were retrospectively reviewed. Seven patients had bilateral clefts (10 open lip clefts, 4 closed lip clefts), eight patients had right-sided unilateral clefts (5 open lip clefts, 3 closed lip clefts), and five patients had left-sided unilateral clefts (3 open lip clefts, 2 closed lip clefts).
Results: Statistically significant correlations were found as follows: Patients with bilateral schizencephalies had significantly worse intellectual (P = .004) and speech (P = .03) development than those with unilateral clefts; patients with unilateral large or medium open lip schizencephalies had significantly worse motor (P = .003) and intellectual (P = .008) impairment than those with unilateral closed lip or small open-lip schizencephalies; patients with frontal lobe involvement had a significantly higher incidence of motor dysfunction than those without frontal lobe involvement (P = .01). Strong similarities were noted in the patient outcomes and the locations of cortical anomalies of patients with schizencephaly and those with nonschizencephaly focal cortical dysplasias.
Conclusion: A common pathogenetic origin for the formation of focal cortical dysplasia in the form of polymicrogyria and schizencephalies is proposed. Patients with small unilateral schizencephalies have a good developmental prognosis, particularly when the motor cortex is not involved.