From the Guidelines
The workup for ataxia should begin with a thorough neurological examination and medical history to determine if the ataxia is acute, subacute, or chronic, as this guides further investigation. According to the most recent study 1, a systematic review of European data, the estimated prevalence of childhood ataxia due to genetic and acquired causes is approximately 26 per 100,000 children. Initial testing should include:
- Brain MRI with contrast to evaluate for structural lesions, stroke, demyelination, or cerebellar atrophy
- Laboratory tests, such as complete blood count, comprehensive metabolic panel, thyroid function tests, vitamin B12 and E levels, and inflammatory markers
- Specific tests for genetic causes, including spinocerebellar ataxia panels, Friedreich's ataxia testing, and tests for metabolic disorders like Wilson's disease (ceruloplasmin levels)
As noted in the study 1, the most common causes of acute ataxia in children are infectious and postinfectious disorders, which accounted for 33.6% of total ataxia cases. Lumbar puncture may be necessary to evaluate for inflammatory or infectious causes, particularly if multiple sclerosis is suspected. Additional specialized tests include:
- Paraneoplastic antibody panels if cancer-associated ataxia is suspected
- Anti-GAD antibodies for immune-mediated ataxia
- Toxicology screening for substance-induced ataxia
- Electromyography and nerve conduction studies to help distinguish cerebellar from sensory ataxia
For patients with a family history of ataxia, genetic counseling and testing are essential 1. This systematic approach helps identify treatable causes of ataxia, which is crucial since many forms have specific treatments while others may be managed symptomatically with physical therapy, occupational therapy, and assistive devices.
From the Research
Diagnostic Approach to Ataxia
The diagnostic workup for ataxia involves a detailed history, neurologic examination, and proper diagnostic tests to confirm the clinical working diagnosis 2. The following steps can be taken:
- Obtain a detailed history to identify potential causes of ataxia
- Perform a neurologic examination to assess for associated symptoms and signs
- Order diagnostic tests, such as genetic tests, laboratory tests, and neuroimaging studies, to confirm the diagnosis
Laboratory and Neuroimaging Tests
Laboratory tests, such as vitamin E and vitamin B12 levels, can help identify underlying causes of ataxia 3, 4. Neuroimaging studies, such as MRI, can help rule out other potential causes of ataxia, such as intracranial masses 4.
Genetic Investigations
Genetic investigations can help identify novel genetic causes of ataxia and provide a more comprehensive understanding of the biological pathways critical for normal cerebellar function 5. Genetic diagnosis can also have prognostic value and implications for family planning.
Treatment and Management
Treatment and management of ataxia depend on the underlying cause. Some disease-specific therapies exist, such as vitamin E for ataxia with vitamin E deficiency and thiamine for Wernicke encephalopathy 3, 5. Antisense oligonucleotides for spinocerebellar ataxias associated with CAG repeat expansions may be a promising therapeutic strategy 5.
Neurophysiological Assessments
Neurophysiological assessments, such as electrophysiology and electroencephalography, can help define the neuronal systems affected by the disease and understand the phenotypes of different types of ataxia 6. Cerebellar brain inhibition (CBI) may be a useful measure of cerebellar function, but its role in the investigation and diagnosis of different types of ataxias is unclear 6.