Ataxia Flashcards
List the causes of ataxia
- Friedreich ataxia
- Ataxia telangiectasia
- Cerebellar agenesis/dysgenesis
- Postinfectious cerebellitis - varicella
- Posterior fossa tumours
- Other hereditary cerebellar ataxias
- Miller Fisher syndrome (variant of Guillain-Barre)
- Mitochondrial disease
- Drugs (e.g. carbamazepine, lamotrigine)
- Toxins (e.g. ethanol)
- Inborn errors of metabolism
- Trauma
- Vascular disorders
- Congenital malformations - Dandy-Walker
- Conversion disorders
How is Friedreich’s ataxia inherited?
Autosomal recessive
Triplet repeat in the FXN gene causing a lack of the frataxin protein.
How does Friedreich’s ataxia present?
- Worsening ataxia
- Dysarthria
- Distal wasting in the lower limbs
- Absent reflexes in lower limbs
- Pes cavus (high arch of the foot that does not flatten with weight bearing)
What physical signs will be present in Friedreich’s ataxia?
- Impairment of joint position and vibration sense
- Extensor plantars
- Optic atrophy
List the complications of Friedreich’s ataxia
- Kyphoscoliosis
- Diabetes mellitus
- Cardiomyopathy
How is Ataxia telangiectasia inherited?
Autosomal recessive
Disorder of DNA repair (double strand break repair)
How does Ataxia telangiectasia present?
- Mild motor delay in infancy
- Delay in ocular pursuits and saccades (moving eyes to a target)
- Difficulty with balance and coordination, particularly evident at school age
- Telangiectasia in the conjunctiva
- Subsequent deterioration with complex eye movement disorder
What features are present in the eye movement disorder associated with Ataxia telangiectasia?
- Nystagmus
- Dystonia
- Spasms
- Jerks and tremors
- Cerebellar ataxia
- Dysarthria
What are the complications of Ataxia telangiectasia?
- Increased susceptibility to infection and deficiencies in IgA and IgE
- Develop malignant disorders (lymphomas and acute leukaemias)
- Develop progressive pulmonary disease with bronchiectasis
- Have a raised serum AFP
- Have sensitivity to ionising radiation
Define ataxia
An abnormality in gait that is wide-based, staggering, and unsteady
What examination steps do we perform in children with ataxia?
- Speech - staccato speech (increased separation of syllables)
- Neurology - Disturbed proprioception, positive Romberg, nystagmus with eye movement
- Systemic - Immunodeficiency in AT, HOCM in Fanconi’s anaemia
What investigations should be performed for ataxia?
- Cerebral imaging if cause not found
- CSF analysis (esp. varicella, strep)
- Metabolic screen (inborn errors of metabolism)
