Acute Cerebellar Ataxia

Originally published at Pediatric EM Morsels on December 22, 2017, updated on July 23, 2017. Reposted with permission.

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Hooven animals are complicated creatures (just like humans). They can be majestic, but rambunctious. They can be wild, yet tamed. In medicine, we often try to distinguish between them: Horses versus Zebras. While searching among the horses for the zebras, we may have in mind that the zebras are rare, which can be true on an individual basis; however, when the group you are searching through is large, the absolute number of zebras can be substantial (see Inborn Errors of Metabolism). The trick is to keep a vigilant eye open, trying to detect even the most subtle of stripes. One of those stripes that will catch your attention is ataxia. Let us take a moment to review one of the common “zebras” in children- Acute Cerebellar Ataxia:


Acute Cerebellar Ataxia: Basics

  • Acute cerebellar ataxia is a common pediatric neurologic problem.
    • Incidence of 1 in 100,000 – 500,000.
  • Some causes of ataxia in children: [Thakkar, 2016]
    • Post-infectious Cerebellar Ataxia – (~30 – 60%)
    • Drug Intoxication (~8%)
      • ex, Alcohol, Benzos, Heavy Metals, CO poisoning, Anticonvulsants
    • Opsoclonus Myoclonus Ataxia (~8%)
      • Rare, but a true medical emergency!
      • May be misdiagnosed as benign post-infectious cause at first.
      • Has severe ataxia, opsoclonus (chaotic ocular movements), and myoclonus.
      • Is a Paraneoplastic disorder (often neuroblastoma)! [Tate, 2005]
    • Acute Cerebellitis (~2%)
      • Most severe end of the spectrum of cerebellar inflammation/infection. [Rossi, 2016]
      • Previously, “Acute Cerebellitis” was used interchangeably with Post-infectious, But:
        • Acute Cerebellitis has a distinctly worse disease course.
        • Has abnormalities on brain MRI.
        • Can lead to rapid posterior fossa edema and lead to morbidity and mortality.
    • Cerebellar Stroke (~2%)
    • Acute Disseminated Encephalomyelitis (ADEM) (~2%)
      • Immunologically mediated inflammatory disease
      • Polyfocal neurological signs (multiple sites involved in CNS)
      • Rapid onset of encephalopathy (altered mental status)
    • Meningitis (<1%)
    • Cerebral Venous Thrombosis (<1%)
    • Miller Fisher Syndrome (<1%)
    • Hereditary conditions (ex, Ataxia-telangiectasia)


Acute Cerebellar Ataxia: Post-infectious

  • The most common cause of acute cerebellar ataxia in children is post-infectious cerebellar ataxia. [Thakkar, 2016; Rossi, 2016]
    • Generally seen in kids younger than 6 years.
    • Most common among 2 – 4 year olds.
  • Presents in a relatively well appearing child who has: [Doan, 2016]
    • Lack of coordination of movement NOT due to paresis,
    • Alterations in tone,
    • Sensory loss, and/or
    • Involuntary movements
  • Often, symptoms begin suddenly.
  • NOT associated with fever, seizures, change in mental status, or other systemic signs. [Doan, 2016]
  • Is a diagnosis of exclusion, because other ominous conditions can present similarly.
  • Commonly associated infections:
    • Varicella [Fursow, 2013]
      • Chickenpox is frequently the cause of acute cerebellar ataxia in the immunosuppressed patient. [Fursow, 2013]
      • Varicella vaccination, however, is protective. [van der Maas, 2009]
    • Epstein-Barr virus
    • Echovirus
    • Enterovirus (Coxsackievirus)
  • Work-up is generally negative!
    • Cerebrospinal fluid analysis has low diagnostic yield. [Thakkar, 2016]
      • Certainly CSF analysis is helpful if you are more concerned for meningitis or encephalitis.
      • LP, if performed, should wait until after imaging to rule-out posterior fossa mass or edema. [Doan, 2016]
    • Imaging is typically normal. [Thakkar, 2016; Doan, 2016]
      • MRI is preferred given higher resolution and superior imaging of posterior fossa. [Rossi, 2016]
      • CT should be obtained for patients with altered mental statusatypical disease courseasymmetric focal neurologic deficits, or when hemorrhage or mass is higher on the Ddx list.
    • “Basic Labs” will be normal.
    • Urine Tox screens should be considered, particularly in the toddlers who like to eat random items in the house. [Doan, 2016]
  • Patient recover without lasting sequelae. [Thakkar, 2016]
    • Usually has resolution of symptoms in 2-8 weeks.
    • Complete resolution by 2-3 months.


Moral of the Morsel:

  • Zebras are common collectively! Look for the subtle stripes!
  • Make kids walk! Yes, toddlers do “toddle,” but shouldn’t be ataxic!
  • Look at the eyes! Nystagmus may be seen with benign conditions, but opsoclonus is scary!



Thakkar K1, Maricich SM2, Alper G3. Acute Ataxia in Childhood: 11-Year Experience at a Major Pediatric Neurology Referral Center. J Child Neurol. 2016 Aug;31(9):1156-60. PMID: 27071467[PubMed] [Read by QxMD]

Rossi A1, Martinetti C2, Morana G2, Severino M2, Tortora D2. Neuroimaging of Infectious and Inflammatory Diseases of the Pediatric Cerebellum and Brainstem. Neuroimaging Clin N Am. 2016 Aug;26(3):471-87. PMID: 27423804[PubMed] [Read by QxMD]

Doan TT1, Masom CP1, Mazzaccaro RJ2, Kane KE1. Acute Cerebellar Ataxia: An Unusual Pediatric Case. J Emerg Med. 2016 May;50(5):769-72. PMID: 26899517[PubMed] [Read by QxMD]

Poretti A1, Benson JE, Huisman TA, Boltshauser E. Acute ataxia in children: approach to clinical presentation and role of additional investigations. Neuropediatrics. 2013 Jun;44(3):127-41. PMID: 23254568[PubMed] [Read by QxMD]

 Medicina (B Aires). 2013;73 Suppl 1:30-7. PMID: 24072049[PubMed] [Read by QxMD]

van der Maas NA1, Bondt PE, de Melker H, Kemmeren JM. Acute cerebellar ataxia in the Netherlands: a study on the association with vaccinations and varicella zoster infection. Vaccine. 2009 Mar 18;27(13):1970-3. PMID: 19186201[PubMed] [Read by QxMD]

Tate ED1, Allison TJ, Pranzatelli MR, Verhulst SJ. Neuroepidemiologic trends in 105 US cases of pediatric opsoclonus-myoclonus syndrome. J Pediatr Oncol Nurs. 2005 Jan-Feb;22(1):8-19. PMID: 15574722[PubMed] [Read by QxMD]

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