Hyaline Protoplasmic Astrocytopathy:  A Clinicopathologic Study.

OBJECTIVES: Hyaline protoplasmic astrocytopathy is a rare condition marked by the accumulation of various proteins in the cytoplasm of protoplasmic astrocytes.

METHODS: This study retrospectively reviews the clinicopathologic features of 14 patients (nine females; mean age, 9.1 years) with hyaline protoplasmic astrocytopathy.

RESULTS: Patients had chronic seizures (mean duration, 101.1 months); mean age at seizure onset was 6.9 months. Three patients had Aicardi syndrome, and one patient had tuberous sclerosis. Associated focal cortical dysplasia was noted in all 14 cases. Patterns of dysplasia observed included International League Against Epilepsy (ILAE) type I Ib (n = 7), ILAE type Ib (n = 4), ILAE type Ic (n = 2), and ILAE type IIa (n = 1). Additional pathologic findings included evidence of contusional damage (n = 5), gray matter nodular heterotopias (n = 3), polymicrogygria (n = 2), hemimegalencephaly (n = 2), and hippocampal sclerosis (ILAE type II, CA1 sclerosis) (n = 1). Postoperative follow-up intervals ranged from two to 93 months (mean, 31.2 months). Seven patients were free of seizures or had only rare disabling seizures (Engel I/II) at most recent follow-up. Two patients had recurrent seizures with no worthwhile improvement (Engel IV) at follow-up.

CONCLUSIONS: The current series supports an association of Aicardi syndrome (21% of cases) and focal cortical dysplasia (100% of cases) and hyaline protoplasmic astrocytopathy.