clinical features

Last reviewed 10/2023

Majority of patients (about 75%) present with typical Friedreich's ataxia:

  • mean age of onset of symptoms is 10 to 15 years
  • neurologic manifestations
    • gait ataxia
      • earliest symptom in vast majority of patients
    • limb ataxia
      • is an early feature of the disease
      • result in difficulty with handwriting, washing, dressing, use of cutlery and carrying drinks or food
    • absent lower limb reflexes
      • is an early sign present in almost all patients and reflects the underlying peripheral neuropathy.
    • weakness and wasting 
      • a relatively late sign
      • more prominent in the lower limbs compared to the upper limbs
    • peripheral sensory neuropathy
      •  reduced/absent vibration sense and proprioception
    • spasticity 
    • visual disturbances
      • optic nerve atrophy – seen in around 25% of patients, often asymptomatic
      • abnormalities of eye movements e.g. - square wave jerks; abnormalities of saccades, pursuit, fixation
    • dysarthria
      • present in more than 90% of individuals
      • is an early sign
    • hearing loss
      • found in 8% to 13% of individuals
    • dysphagia
      • is common and present in around 92% of individuals with FRDA
    • cognition
      • cognition is generally not affected
      • there can be impairment in verbal fluency, visuoconstructive and visuoperceptual capacity, and motor and mental reaction times 
  • non neurological features
    • cardiac complications
      • hypertrophic cardiomyopathy
      • abnormal electrocardiogram 
    • diabetes mellitus
    • skeletal abnormalities
      • scoliosis
      • foot abnormalities - pes cavus, talipes equinovarus
    • sleep disordered breathing and sleep apnoea 
    • urinary frequency and urgency  (1,2,3)

Atypical presentation is seen in 25% of patients with FRDA e.g. -

  • late-onset FRDA (LOFA) and very late-onset FRDA (VLOFA)
    • onset is later than age 25 years
      • in LOFA, the age of onset is 26-39 years while in VLOFA, the age of onset is over 40 years
  • FRDA with retained reflexes (FARR) 
  • FRDA in Acadian      
    •  have a later age of onset and of wheelchair confinement, and a much lower incidence of cardiomyopathy (1,2,3)

Reference:

Related pages:

dysarthria

pes cavus

peripheral neuropathy

kyphoscoliosis

ataxia

nystagmus

retinitis pigmentosa

optic atrophy

cardiomyopathy