Ataxia

Ataxia

1. Friedrich ataxia

   • autosomal recessive
   • Frataxin gene mutation
     • repeat disorder
     • presents w/
       • worsening ataxia
       • distal wasting in legs
       • absent lower limb reflexes
         • but extensor plantar responses
         • due to pyramidal involvement
       • pes cavus
       • dysarthria
   • similar to hereditary motor sensory neuropathies
     • but in FA there is
       • impairment of
         • joint position
         • vibration sense
       • extensor plantars
       • often optic neuropathy
   • cerebellar component becomes more advanced w/ age
   • evolving kyphoscoliosis & cardiomyopathy
     • can -> cardioresp compromise & death @ 40-50 years old

2. Ataxia telangiectasia

   • disorder of DNA repair
   • autosomal recessive
   • ATM gene IDed
   • presentation
     • infancy
       • mild delay in motor development
       • oculomotor probs
         • incoordination
         • delay in ocular pursuit of objects (oculomotor dyspraxia)
     • school age
       • difficulty w/ balance
       • difficulty w/ coordination
     • from 4 years old
       • telangiectasia in
         • conjunctiva
         • neck
         • shoulders
   • many kids need a wheelchair
   • risks
     • increased vulnerability to infection
       • mostly from IgA surface antibody defect
     • developing malignant disorders
       • mostly acute lymphoblastic leukaemia
     • have raised serum alpha fetoprotein
     • increased white cell sensitivity to irradiation
       • can be used diagnostically
   • diag
     • ATM gene test

3. other hereditary cerebellar ataxias

   • growing number
   • largely dominantly inherited
   • relatively benign course in childhood