Table 1.

The differences between hereditary cerebellar ataxia and hereditary spastic paraplegia.

	Hereditary cerebellar ataxia	Hereditary spastic paraplegia
Epidemiology	Approximately 1–9 in 100,000 people	Approximately 2–6 in 100,000 people
Pathology	Purkinje cells and/or spinocerebellar tract involvement combined with atrophy of brainstem or other regions of the nervous system	Pyramidal tract degeneration accompanied by posterior cordonal tract impairment
Etiological Mechanism	Neuronal loss in the cerebellum	Distal axonal degeneration of the longest tract within the central nervous system
Mode of Inheritance	Mostly inherited through autosomal dominant and recessive transmission but all the known inheritance patterns are observed	Mostly inherited through autosomal dominant and recessive transmission but all the known inheritance patterns are observed
Clinical Features	Cerebellar syndrome with progressive gait and limb ataxia, loss of coordination, nystagmus and other oculomotor control signs, and dysarthria	Pyramidal signs with pyramidal weakness in the lower limbs, spasticity, hyperreflexia, and bilateral upgoing toes
Radiological Characteristics	Atrophy of the cerebellum is a relatively constant finding. Extracerebellar regions are also affected depending on the specific type of ataxia	Non-specific and variable findings, which include corpus callosum atrophy, increased T2 signal intensity in the posterior limb of the internal capsule, spinal cord atrophy, and ears of the lynx sign (high T2/FLAIR signal intensity at the tip of the frontal horns of the lateral ventricles)