Neurology & Neurosurgery

Neurofibromatosis type I (NF1)

It is the most common neurocutaneous disorder with incidence 1:3000. Inheritance is an autosomal dominant pattern, but approximately half of NF1 cases result from a spontaneous mutation.  The disorder is due to a mutation in the NF1 gene at chromosome 17q11 (neuraofibromin protein). Main characteristics of the disease are café au lait spots (more than 6, > 5 mm diameter), axillary freckling, neurofibromas; opticg lioma, Lisch nodules (iris hamartomas); osseous lesions (thin cortex, sphenoid dysplasia, scoliosis).

Diagnostic criteria for NF1 (need 2 of 7)

• Axillary/inguinal freckles
• Bone deform ties: sphenoid dysplasia, thinning of long bones
• Cafe au lait patches (Need six measuring 5 mm if prepubertal.5 mm if postpubertal)
• 1st Degree relative
• Eye findings: Lisch nodules (> 2)
• Fibromas (> 2 neurofibromas or 1 plexiform neurofibroma)
• Glioma of optic nerve

Neurofibromatosis type II (NF2)

NF2 disorder has incidence1:50,000. Inheritance is an autosomal dominant pattern with also de novo mutations of NF2 gene at chromosome 22q11 (merlin protein). It is characterized by acoustic neuromas, meningiomas, neurofibroma, glioma, schwannoma.

Diagnostic criteria for NF2 (only one criterion required)

• Bilateral acoustic neuroma
• Positive family history (parent, child or sib) and either unilateral acoustic neuroma or 1 of the following:
• neurofibroma, meningioma, glioma, schwannoma, or posterior capsular cataract (at young age)

Tuberous Sclerosis (TSC)

Tuberous sclerosis is the second most common neurocutaneous disorder with a prevalence of 1 per 6000 to 9000 individuals. The inheritance of TSC is as an autosomal dominant with 66% to 86% cases result from a spontaneous mutation. It is a disorder that can affect the brain, skin, kidneys, heart, and other organs.  Two genes are responsible for tuberous sclerosis the TSC1 at chromosome 9q34.3; (hamartin protein), and TSC2 at cheromosome 16p13.3 (tuberin protein). Main characteristics are: ash-leaf spots, shagreen patches, café au lait spots, subependymal giant cell astrocytoma (SEGA), cortical tubers. adenoma sebaceum, subungual fibromas; epilepsy (infantile spasms, etc), mental retardation, intracranial calcifications; cardiac rhabdomyoma; renal anomalies

Sturge Weber syndrome

It is a sporadic disorder. The main characteristics of Sturge Weber disease are port-wine stain around the ophthalmic branch of the trigeminal nerve, vascular malformation involving the ipsilateral cerebral cortex. intracerebral calcifications,  seizures, mental retardation, intracerebral calcifications