Clinical scenario: Focal seizures | Capillary malformation| Raised ICP| Calcification
A 7-month-old infant is brought with recurrent focal seizures involving the right arm and face since the age of 5 months. Development has become progressively delayed. He was born with a reddish-purple capillary malformation involving the left forehead and upper eyelid, which has remained unchanged.
On examination:
- Head circumference: 10th percentile
- Right-sided hyperreflexia with mild hemiparesis
- The skin lesion involves the ophthalmic (V1) distribution of the trigeminal nerve
- Fundoscopy reveals raised intraocular pressure in the left eye.
Contrast-enhanced MRI brain demonstrates left leptomeningeal enhancement, and CT brain shows gyriform (“tram-track”) cortical calcifications over the left parieto-occipital region.
Which of the following is the most likely diagnosis?
A. Neurofibromatosis type 1
B. Sturge-Weber syndrome
C. Tuberous sclerosis complex
D. Von Hippel-Lindau syndrome
E. PHACE syndrome
Correct answer & Explanation:
Correct Answer: B. Sturge-Weber syndrome
Explanation:
Sturge-Weber syndrome (SWS) is a sporadic neurocutaneous disorder caused by a somatic activating mutation in the GNAQ gene. It is characterized by the triad of:
- Facial capillary malformation (port-wine stain), typically involving the V1 (ophthalmic) distribution of the trigeminal nerve.
- Leptomeningeal angiomatosis, leading to seizures, stroke-like episodes, hemiparesis, and developmental delay.
- Ocular abnormalities, especially glaucoma.
The characteristic neuroimaging findings include:
- Leptomeningeal enhancement on contrast MRI.
- Gyriform (“tram-track”) cortical calcifications on CT, usually in the parieto-occipital region.
Why the other options are incorrect
- A. Neurofibromatosis type 1: Associated with café-au-lait macules, neurofibromas, axillary freckling, and optic pathway gliomas.
- B. Sturge-Weber syndrome: Correct. Port-wine stain in the V1 distribution, seizures, glaucoma, and leptomeningeal angiomatosis are classic.
- C. Tuberous sclerosis complex: Characterized by hypomelanotic macules, facial angiofibromas, cortical tubers, and subependymal nodules.
- D. Von Hippel-Lindau syndrome: Associated with retinal angiomas, CNS hemangioblastomas, and renal tumors.
- Learning Point
A port-wine stain involving the V1 distribution, especially when associated with early-onset focal seizures, should prompt evaluation for Sturge-Weber syndrome, including:
- MRI with contrast to detect leptomeningeal angiomatosis.
- Ophthalmologic assessment for glaucoma.
- Early seizure management and developmental follow-up.
