What Causes Ataxia?

Patient Presentation
A 33-month-old male was transferred to the inpatient unit with difficulty walking. One month ago he has Influenza A and one week ago he had diarrhea. Just before bed on the night before he seemed to walk a little funny but his maternal aunt thought that he was just tired. In the morning, the aunt saw that he was truly having problems walking and would fall backwards. He also seemed very fussy. He was taken to the local emergency room where his complete blood count, C-reactive protein, electrolytes, liver function tests, amylase and lipase, rapid strep test, urine toxicology screen and a head computed tomogram were negative. He was transferred to the regional children’s hospital for further evaluation. The past medical history was positive for otitis medias and colds. He received appropriate health supervision visits and had been developing normally. The review of systems was negative for rash, fever, with no changes in level of consciousness, and bowel or bladder. He was now refusing to eat and drink.

The pertinent physical exam showed a fussy toddler with normal vital signs including blood pressure. His neurological examination showed significant ataxia with walking including a wide-based gait. When standing he had problems catching himself, would lean backwards and fall. He had truncal ataxia with sitting. There was normal vision, hearing and sensation. His DTR were +2 and he had normal strength. The work-up included an extended urine toxicology screen that was negative. His head magnetic resonance imaging and a lumbar puncture were normal. The diagnosis of acute cerebellar ataxia most likely due to a viral infection was made. Over the next few days, the patient was able to eat and drink more and became steadier on his feet. He was discharged and followed up with his local physician at one week who reported that he was able to sit and walk normally, but still would fall if he tried to run. At a followup neurology appointment at one month, his examination was normal. Infectious disease studies of the cerebral spinal fluid were unable to identify an organism.


Coordination and balance problems are caused by various problems affecting the central and peripheral nervous system. Normal development of a child or weakness of a child are commonly mistaken for true ataxia. Ataxia specifically refers to “…impairment of the coordination of movement without loss of muscle strength.” If it is purely due to abnormalities of the cerebellum then there should be no changes in mental status, sensation or weakness. Sometimes it is difficult to determine if there are abnormalities in other areas. For example, Guillian-Barre often presents with difficulty or clumsy walking. Sometimes can be difficult with an uncooperative or scared young child to determine if there are sensation changes or weakness particularly early in the disease process. Therefore the child may be misclassified as having ataxia.

Acute cerebellar ataxia was first described in 1868 by Shepherd. It has an acute onset that is usually followed by a complete recovery and good long-term prognosis. It is thought to be caused by an transient para- or post-infectious process but has not been specifically identified. Organisms that have been associated with acute cerebellar ataxia include:

    • Bacterial
      • Bordetella pertussis
      • Streptococcus, group A beta-hemolytic
      • Legionella
      • Mycoplasma
    • Viral
      • Epstein-Barr virus
      • Influenza
      • Hepatitis A and B
      • Herpes simplex
      • Measles
      • Mumps
      • Parvovirus B19
      • Polio
      • Varicella

Patients present with acute ataxia with gross and fine motor problems. Resolution is within days to a few weeks but a small number of patients do have permanent problems.
Treatment is supportive with watchful waiting. Physical therapy may help patients to cope with the symptoms.

Learning Point
The differential diagnosis of ataxia includes:

  • Acute
    • Acute cerebellar ataxia
    • Drug reaction, intoxication including lead
    • Encephalomyelitis, postinfectious
    • Head trauma – concussion, subdural hematoma
    • Hydrocephalus
    • Hysteria
    • Metabolic abnormalities – hypoglycemia, hypothyroidism
    • Meningitis (usually does not present solely with ataxia)
    • Tumor – posterior fossa
    • Labyrinthitis
    • Stroke
    • Weakness (mistaken for ataxia)
  • Chronic
    • Abetalipoproteinemia
    • Ataxia-telangectasia
    • Congenital anomalies of cerebellum
    • Friedrich’s ataxia
    • Hydrocephalus
    • Leigh’s syndrome (subacute necrotizing encephalopathy)
    • Tumor – posterior fossa
    • Various hereditary ataxias

Questions for Further Discussion
1. What are indications for consultation with a neurologist for ataxia?
2. What are indications for neuroimaging with ataxia?
3. How does opsiclonus-myoclonus present?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Acute Cerebellar Ataxia

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Illingworth RS. Common Symptoms of Disease in Children. Blackwell Scientific Publications: Oxford. 1988:17-19.

Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996:49-52.

Fogel BL. Childhood cerebellar ataxia. J Child Neurol. 2012 Sep;27(9):1138-45.

Desai J, Mitchell WG. Acute cerebellar ataxia, acute cerebellitis, and opsoclonus-myoclonus syndrome. J Child Neurol. 2012 Nov;27(11):1482-8.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.


    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital