Phakomatoses are a group of neurocutaneous disorders characterised by involvement of structures that arise from the embryonic ectoderm (thus central nervous system, skin and eyes). Other organs may also be involved

TSC1: chromosome 9q32-34

TSC2: chromosome 16p13.3 (accounts for most cases)

Radiographic features

Tuberous sclerosis has a great number of manifestations, involving many organ systems. The most common manifestations are:

1. 
   cortical or subependymal tubers and white matter abnormalities
   
2. 
   renal angiomyolipomas (AML)
   
3. 
   cardiac rhabdomyoma(s)
   

Neurological 

• 
  cortical / subcortical tubers: 50% are in the frontal lobe : high T2 and low T1 with only 10% of tubers showing enhancement
  
• 
  subependymal hamartomas
  
  • 
    88% are associated with calcification, although calcification absent in early childhood
    
  • 
    visible within the first 6 months of age ¹¹
    
  • 
    variable signal, frequently high T1 and iso to high T2
    
  • 
    enhancement is variable and is not a useful feature in distinguishing them from subependymal giant cell astrocytomas (SGCA); only serial growth is reliable^9-10
    
• 
  subependymal giant cell astrocytomas (SGCA)
  
  • 
    peak occurance 8-18 years
    
  • 
    tend to be large and demonstrate growth ^9-10
    
  • 
    tend to have intense enhancement
    
• 
  white matter abnormalities
  
  • 
    variable appearance, with nodular, ill-defined, cystic and band like lesions seen
    
  • 
    radial bands are thought to be relatively specific for TS ¹²
    
• 
  retinal phakomas
  
• 
  rarer findings
  
  • 
    cerebellar atrophy
    
  • 
    infarcts (due to vascular occlusive disorders)
    
  • 
    cerebral aneurysms
    
  • 
    dysgenesis of the corpus callosum
    
  • 
    Chiari malformations
    
  • 
    microcephaly
    
  • 
    arachnoid cysts
    
  • 
    chordoma