Neurology

Ataxia

Introduction

Ataxia is defined as impaired balance and poor coordination of intentional movements, resulting in unsteady gait. Most often arrising from cerebellar dysfunction. The acute onset of ataxia, although rare, is very frightening to parents and children and must be evaluated quickly. Most cases are benign and self-limiting, however many different etiologies of ataxia exist making a careful history and physical imperative.

 

History

  1. Onset. Was it acute or are the symptoms chronic? Any similar past history?
  2. Has there been fever, vomiting, headaches, or lethargy?
  3. Has there been a recent viral illness? Any healing scars from chickenpox?
  4. Is the child taking any medications?
  5. Ask about possible ingestions
  6. Has the child been depressed?
  7. Has there been a history of convulsions?
  8. Has there been a recent ear infection?
  9. Has there been any changes in the child's speech?
  10. Developmental history
  11. Steatorrhea?
  12. Has there been increased number of infections of the upper respiratory tract?

 

Physical examination

  1. Vital signs including blood pressure.
  2. Check for signs of increased intracranial pressure.
  3. Careful examination of the middle ear
  4. Skin examination looking for evidence of old chickenpox scars.
  5. Hepatosplenomegaly
  6. Fundoscopic examination
  7. Neurologic examination
    1. strength
    2. reflexes 
    3. Gait analysis- ataxic characteristically wide based
    4. intention tremor
    5. past pointing (finger-to-nose)
    6. dorsal tract findings.
  8. Romberg test

 

Associated Symptoms

  1. Otalgia, vertigo and vomiting suggest acute labrynthitis
  2. Increased intracranial pressure suggests intracranial mass and/or hydrocephalus. Symptoms include nightime or early morning headaches, papilledema or personality changes.
  3. Recent rashes suggesting preceding infectious etiology

 

Etiology

See diagram of differential diagnosis to the right.

Acute Ataxia

  1. Infections
    1. Bacterial meningitis
    2. Viral meningoencephalitis- mumps, enteroviral, and others
    3. Cerebellar Abcess (often following otitis media or mastoiditis)
  2. Post-infectious (more common than infectious) Common 2-3 week following chickenpox. Also may be other viruses including Enteroviruses, and influenza. Child's gait most often affected. Majority of cases recover fully. Imaging of CNS is normal. Initial CSF has wbcs and later will develop protein elevation. Includes ADEM (Acute Disseminated Encephalomyelitis) a rare inflammatory demyelinating disease.
  3. Guillain-Barre Syndrome
  4. Ingestions
    1. Barbiturates
    2. Phenothiazines
    3. Alcohol
    4. Anti-convulsants
    5. Street drugs - cannabis
  5. Opsoclonus-polymyoclonus syndrome. Muscle jerks with associated nystagmus. Evaluate for neuroblastoma in abdomen or mediastinum by xray or checking for catacholamine metabolites.
  6. Labyrinthitis- vertigo, nausea, and vomtiing
  7. Intracranial Hemmorhage or Stroke

Chronic Intermittent

  1. Migraines
  2. Familial disorders 
  3. Inborn Errors of Metabolism

Chronic Progressive Disorders

  1. Medulloblastomas, astrocytomas, brain stem gliomas
  2. Hydrocephalus
  3. Inborn errors of metabolism causes neurodegeneration
  4. Ataxia telangectasia- Autosomal recessive, iimmunodeficiency, telangectasia start later in life.
  5. Frederich's ataxia- autosomal recessive, posterior tract findings, pes cavus.
  6. Congenital Anomaly (Dandi-Walker, Chiari Malformations)

 

Evaluation

  1. Thorough history and physical examination
  2. Laboratory evaluation may include blood glucose, cbc, electrolytes, 
  3. If suspect infection, csf examination after ruling out increased intracranial pressure
  4. Neuroimaging, MRI preffered over CT for posterior fossa due to bone artifact in CT

 

Treatment

Treatment obviously varies widely depending on etiology. Early intervention is vital in cases associated with increased intracranial pressure, acute infeciton or cerebrovascular accident. Other cases require careful evaluation to rule out other processes. With proper evaluation most cases will require nothing more than continued monitoring with supportive therapy.

 

Reference

  1. Dunn D. and Patel H. Ataxia: From the benign to the ominous. Contemporary Pediatrics July 1991 
  2. DeAngelis C. Consultation with the Specialist: Ataxia Peds in Review March 1995
  3. Dinolfo E. Evaluation of Ataxia Peds in Review May 2001
  4. Benun J. et al. Balance and Vertigo in Children.  Peds in Review Feb 2011
  5. Fogel B.L. Childhood Cerebellar Ataxia. Journal of Child Neurology July 4, 2012