neurocutaneous syndromes

nervous sys & skin- ectodermal origin
1. embryological disruption causes neurocutaneous syndromes
neurofibromatosis type 1 (NF1)
1. affects 1 in 3000 live births
  1. 1/3 have new mutations
2. autosomal dominant, highly penetrant
3. the gene has been IDed
4. diag
  1. 2 or more of these criteria
    1. 6 or more cafe au lait spots
      1. > 5mm in size before puberty
      2. > 15mm after puberty
    2. > 1 neurofibroma unsightly firm nodular overgrowth over any nerve)
    3. axillary freckles
    4. optic glioma
      1. may cause visual impairment
    5. 1 Lisch nodule (harmartoma of iris seen on slit lamp exam)
    6. bony lesions from sphenoid dysplasia
      1. can cause eye protrusion
    7. a 1st degree relative w/ NF1
5. cutaneous features
  1. more evident after puberty
  2. wide spectrum of involvement
  3. neurofibromata
    1. appear on course of any peripheral nerve
      1. incl cranial nn
        compression of CN2 or CN8->visual/auditory imp
    2. may look unsightly
    3. may cause neuro signs
      1. if they occur @ a site where a peripheral n passes through a bony foramen
6. megalencephaly
  1. w/ LD
  2. w/ epilepsy
7. most ppl just have the cutaneous stigmata
NF2
1. bilat, acoustic or central
2. less common
3. presents in teen years
4. bilat acoustic neuroma are predominant feature
  1. present w/
    1. deafness
    2. cerebellopontine angle syn
      1. CN7 paresis
      2. cerebellar ataxia
  2. rarely the benign tumours undergo sarcomatous change
5. there may be overlap btw NF1 & NF2
  1. NF1 & NF2 can be assoc with
    1. MEN syndromes
    2. phaeochromocytoma
    3. pulmonary hypertension
    4. renal artery stenosis w/ hyperetension
    5. gliomatous change
      1. esp CNS lesions
tuberous sclerosis
1. dominantly inherited
  1. but up to 70% are new mutations
2. prevalence= 1 in 9000 live births
3. cutaneous features
  1. depigmented ash leaf-shaped patches
    1. fluoresce under Wood's light (UV light)
  2. roughened patches of skin (shagreen patches) usually over the lumbar spine
  3. adenoma sebaceum (angiofibromata)
    1. in butterfly distribution over bridge of nose & cheecks
    2. unusual before 3 years
4. neuro features
  1. infantile spasms & developmental delay
  2. epilepsy-often focal
  3. intellectual impairment
5. severe LD
6. other features
  1. fibromata under nails (subungual fibromata)
  2. phakomata (dense white areas on the retina)
    1. from local degen
  3. rhabdomyomata of the heart
    1. IDable in early weeks on echo but resolve in infancy
  4. polycystic kidneys
7. gliomatous change can occur in the brain lesions
8. autistic features to behaviour when older
9. CT scans
  1. detect calcified subependymal nodules & tubers from 2nd yr of life
10. MRI
  1. more sensitive & more clearly IDs other tubers & lesions
Sturge-Weber syn
1. sporadic disorder
2. a haemangiomatous facial lesion (port wine stain)
  1. in distribution of CN5 assoc w/ a similar lesion intracranially
    1. ophthalmic division always involved
3. imaging
  1. MRI
    1. modality of choice now
  2. skull x-ray
    1. characteristic rail-road track calcification
      1. classification of the gyri
4. most severe form
  1. epilepsy
    1. if intractable and presenting in early infancy
      1. hemispherectomy may help
  2. LD
  3. hemiplegia
5. less severely affected
  1. seizures & LD
  2. deterioration unusual after 5 years old
6. high risk of glaucoma
  1. assess this in neonatal period

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neurocutaneous syndromes

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	Created by v.djabatey over 10 years ago