Forehead plaque: A cutaneous marker of CNS involvement in tuberous sclerosis

Abstract

Tuberous sclerosis complex (TSC) is a neurocutaneous genodermatosis characterized by hamartoma formation in multiple organs. There are no definite cutaneous markers suggestive of central nervous system (CNS) involvement in TSC. To study association of forehead plaque seen in tuberous sclerosis patients and CNS involvement in TSC. This is a retrospective study of 15 cases of tuberous sclerosis in varying age groups - from 1.5 to 50 years. All the cases were thoroughly evaluated with detailed history; clinical examination; and relevant investigations like X-rays of chest, skull, hands and feet; ultrasound abdomen and computed tomography of brain. Out of the 15 cases, CNS involvement was seen in 8 cases. Seizures were present in 8 cases (53.33%) and mental retardation was seen in 6 cases (40%). Computerized tomography of brain revealed subependymal nodules (SENs) in eight cases (53.33%). In addition to SENs, subependymal giant cell astrocytomas and cortical tubers were seen in 2 cases each. Out of these 8 cases having CNS involvement, in 7 cases forehead plaque was observed. In 1 case, no forehead plaque was observed (X 2 = 1.07, P < 0.05). This study shows that there is a statistically significant relationship between the presence of a forehead plaque and CNS involvement in TSC. Therefore, forehead plaque may be considered as a novel cutaneous marker to know the CNS involvement in TSC at an early stage.