What's spinocerebellar ataxia type 3?
Spinocerebellar ataxia type 3, also called Machado-Joseph disease, is the second most common autosomal dominant hereditary ataxia; it often presents with impaired eye movements and balance problems.
| Features mapped | 7 |
|---|---|
| Treatments mapped | 1 |
| Published sources | 5 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Diplopia
Diplopia (double vision) is one of the most frequently reported symptoms of spinocerebellar ataxia type 3.
Nystagmus
Nystagmus (involuntary eye movements), including gaze-evoked and rebound forms, is among the eye-movement abnormalities commonly found in spinocerebellar ataxia type 3.
Progressive cerebellar ataxia
Cerebellar ataxia affecting limb coordination is a core feature of spinocerebellar ataxia type 3, present in essentially all patients in a clinical series.
Dysarthria
Dysarthria (slurred, effortful speech) is common in spinocerebellar ataxia type 3, reported in around 90% of patients in a clinical series.
Abnormal pyramidal sign
Pyramidal signs, including spasticity (muscle stiffness), can develop in spinocerebellar ataxia type 3, often in mid-adulthood.
Dystonia
Dystonia (involuntary muscle contractions causing abnormal postures) can occur in spinocerebellar ataxia type 3, often in mid-adulthood.
Respiratory insufficiency
Respiratory insufficiency can develop in spinocerebellar ataxia type 3; respiratory failure is the leading cause of death and is managed with chest physiotherapy and respiratory training.
“Spinocerebellar ataxia type 3 (SCA3) is one of the most prevalent hereditary neurodegenerative disorders, with respiratory failure being the leading cause of mortality.”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
chest physiotherapy
Chest physiotherapy and respiratory training are used in the clinical management of spinocerebellar ataxia type 3.
Used to help with: Respiratory insufficiency.
“…early intervention with chest physiotherapy and respiratory training as part of the clinical management of…”
How to read the evidence labels
Where this comes from
This guide is built from 5 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.