Tuberous Sclerosis : Case Report

Case

History- 13 months male child presents for MRI brain with multiple episodes of seizures. Case Submitted by Dr MGK Murthy, Dr GA Prasad

MR  findings

Multifocal ill defined lesions of varying sizes with T1 hypo intense & T2/FLAIR  hyper intense signal  seen in supratentorial  neuroparenchyma in all the lobes involving the cortical & subcortical regions with areas of cortical thickening & expansion without any  diffusion restriction or blooming.

Multiple subependymal nodules in body & trigone of both lateral ventricles with foci of blooming in few of them suggesting calcifications. Ill defined T2 hyperintense signal in bilateral deep periventricular white matter & few thin band like T2 hyperintense signal in right frontal lobe white matter anteriorly. Findings are suggestive of neurocutaneous syndrome – Tuberous Sclerosis with cortical/subcortical tubers, subependymal hamartomas & white matter radial bands.

Discussion

Tuberous sclerosis is an autosomal dominant neurocutaneous syndrome characterized by various abnormalities, including multisystemic hamartomas. Also known as Bourneville disease, named after Désiré-Magloire Bourneville, the French physician who discovered the potato like appearance of cortical lesions in the brains of patients with this condition.Tuberous sclerosis is the second most common phakomatosis behind neurofibromatosis type 1. It has a prevalence estimated to be 1 in 6000. Approximately one third of cases of tuberous sclerosis are familial the other two thirds of cases are sporadic and due to spontaneous mutations.

Classic triad first described by Heinrich Vogt in 1908 consists of facial angiofibromas, seizures, and mental retardation is present in only 30–40% of patients. Facial angiofibromas are present 75% of the time, seizures as much as 90% of the time, and mental retardation in approximately 50% of all patients. Tuberous sclerosis is usually diagnosed in infancy or early childhood because child presents with seizures, developmental delay or hypomelanotic macules.

 The diagnosis of tuberous sclerosis can be made earlier or later on the basis of other features that manifest themselves at other ages. Cortical tubers and cardiac rhabdomyomas can be detected prenatally and in infancy, whereas renal, pulmonary, and osseous lesions are identified more commonly in adulthood.

Genetic diagnostic criteria - The identification of either a TSC1 or TSC2 pathogenic mutation in DNA from normal tissue is sufficient to make a definite diagnosis of tuberous sclerosis complex (TSC).

Clinical diagnostic criteria

Major features

Hypomelanotic macules (≥3, at least 5-mm diameter)

Angiofibromas (≥3) or fibrous cephalic plaque

Ungual fibromas (≥2)

Shagreen patch

Multiple retinal hamartomas

Cortical dysplasias

Subependymal nodules

Subependymal giant cell astrocytoma

Cardiac rhabdomyoma

Lymphangioleiomyomatosis (LAM)

Angiomyolipomas (≥2)†

Minor features

“Confetti” skin lesions

Dental enamel pits (>3)

Intraoral fibromas (≥2)

Retinal achromic patch

Multiple renal cysts

Nonrenal hamartomas

Definite diagnosis: Two major features or one major feature with ≥2 minor features

Possible diagnosis: Either one major feature or ≥2 minor features