Table 2 Comparison between Friedreich ataxia and Charcot-Marie-Tooth neuropathy type 4C
From: The cerebellar phenotype of Charcot-Marie-Tooth neuropathy type 4C
| Features |
Friedreich ataxia (FRDA) | Charcot-Marie-Tooth neuropathy type 4C (CMT4C) |
|---|---|---|
| Age of onset | Childhood-adolescence | Childhood |
| Course of disease | Typically early loss of mobility | Loss of mobility in some |
| Prognosis | Reduced life span | Life expectancy unaffected |
| Scoliosis | Y (Very common) | Y |
| Type of polyneuropathy | Axonal sensory | Demyelinating motor and sensory |
| Myokymia | N | Y |
| Foot deformity | Y | Y |
| Hearing loss | Y (20%) | Y (12%) [3] |
| Eye movement abnormalities | Square wave jerks most commonly [12] | Nystagmus in a few patients |
| Vestibular signs | Y | Y |
| Risk for diabetes | Y (20%) | N |
| Hypertrophic cardiomyopathy | Y [13] | N |
| Respiratory failure | N | Y |
| Cerebellar atrophy | In late stages | Very rare |
| Spinal cord atrophy | Y | Unknown |
| Other radiological abnormalities |
Iron accumulation in the dentate nuclei Atrophy of dentate nuclei [9] | Thickening of cranial nerves |
| Pathology of the brain, spinal cord and dorsal roots | Depletion of myelinated fibers in posterior columns, neuronal loss in the dorsal nuclei of Clarke columns thinning of dorsal roots and spinal cord [14], progressive atrophy of the dentate nucleus [15] | Unknown |