Forehead plaque: a cutaneous marker of CNS involvement in tuberous sclerosis.

BACKGROUND: 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.

AIMS: To study association of forehead plaque seen in tuberous sclerosis patients and CNS involvement in TSC.

METHODS: 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.

RESULTS: 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).

CONCLUSION: 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.