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Ataxia, Emergency Medicine

Basics

Description

- Gait disturbance: - Ataxia often presents with unsteady gait - Initial sense of insecurity while walking - Problems with special skills (bicycling, skiing, climbing) - Sense of imbalance - Wide base stance and staggering gait - Test tandem gait to identify subtle ataxia

- Limb ataxia: - Incoordination - Intention tremors - Clumsiness with writing, picking up objects, buttoning - Dysmetria: Under- or overshooting on finger-to-nose and heel-to-shin testing - Dysdiadochokinesis: Difficulty with rapid alternating movements

- Dysarthria and bulbar symptoms: - Slurred speech - Staccato, scanning speech - Choking from incoordination of swallowing

- Visual abnormalities: - Blurry vision - Vertigo: - Distinguish central from peripheral vertigo - Peripheral vertigo is often severe, triggered by movement, and may be accompanied by ear pain, hearing loss, or tinnitus

- Nystagmus: - Gaze-evoked nystagmus: Repetitive drifts to the midline followed by fast phase to the eccentric side - Rebound nystagmus

- Sensory ataxia: - Paresthesias - Numbness - Cautious, steppage gait - Marked worsening of coordination with eyes closed: - A positive Romberg sign is the classic finding in sensory ataxia

- Perform a complete physical exam, including neurological and gait testing - Assess for signs or symptoms of acute, life-threatening disorders such as hemorrhage, stroke, or CNS infection: - Altered mental status - Headache - Focal neurological deficits - Elevated intracranial pressure: - Bradycardia, HTN, abnormal respiratory pattern - Papilledema - Bulging fontanelles

- Fever - Meningismus - Nystagmus - Nausea/vomiting - Examine ears and perform provocative testing for nystagmus (Dix-Hallpike)

- CT: - Head CT can identify mass, hemorrhage, subacute infarct, or hydrocephalus - Consider CT with and without IV contrast if mass suspected - CT angiography can be performed to evaluate for vascular disease

- Vitamin B1 or B12 deficiency - Paraneoplastic syndromes: - Breast/ovarian cancer - Hodgkin lymphoma - Neuroblastoma

- Lyme disease - Toxoplasmosis - Creutzfeldt-Jakob disease

- Acute cerebellar ataxia: - Postinfectious cerebellar demyelination - Usually occurs in children 2-5 yr old - Onset 1-3 wk after triggering illness - Over 1/4 of cases occur after varicella, but linked to many viral infections and immunizations - Normal mental status - No fever, focal deficits, or seizures - Mild cases may be managed at home, but require injury prevention counseling - Most children recover completely within 3 mo without intervention

  • Inability to perform coordinated movements
  • Caused by a disorder of the cerebellum or its connections:Ipsilateral signs with lateral cerebellar lesionsTruncal ataxia with midline lesions

Etiology

Usually cerebellar in origin, but may occur with sensory, motor, or vestibular dysfunction:

  • Trauma
  • Mass lesions
  • Vascular disorders
  • Infections or postinfectious processes
  • Toxins/drugs
  • Metabolic/endocrine derangements
  • Demyelinating diseases
  • Congenital malformations
  • Hereditary disorders:Inborn errors of metabolismProgressive degenerative ataxias
  • Nutritional deficiencies

Diagnosis

Signs and Symptoms

  • Gait disturbance:Ataxia often presents with unsteady gaitInitial sense of insecurity while walkingProblems with special skills (bicycling, skiing, climbing)Sense of imbalanceWide base stance and staggering gaitTest tandem gait to identify subtle ataxia
  • Limb ataxia:IncoordinationIntention tremorsClumsiness with writing, picking up objects, buttoningDysmetria: Under- or overshooting on finger-to-nose and heel-to-shin testingDysdiadochokinesis: Difficulty with rapid alternating movements
  • Truncal ataxia:Head tremorsTruncal instabilityTitubation: Swaying of the head/trunk while at rest
  • Dysarthria and bulbar symptoms:Slurred speechStaccato, scanning speechChoking from incoordination of swallowing
  • Visual abnormalities:Blurry visionVertigo:Distinguish central from peripheral vertigoPeripheral vertigo is often severe, triggered by movement, and may be accompanied by ear pain, hearing loss, or tinnitusNystagmus:Gaze-evoked nystagmus: Repetitive drifts to the midline followed by fast phase to the eccentric sideRebound nystagmus
  • Abnormalities of muscle tone and strength:Isometrataxia: Difficulty sustaining constant force during hand use:Ask patient to hold slight, steady pinching pressure against examiners finger (examiner will feel irregular pressure)True muscle weakness or hypotonia uncommon in cerebellar disease
  • Sensory ataxia:ParesthesiasNumbnessCautious, steppage gaitMarked worsening of coordination with eyes closed:A positive Romberg sign is the classic finding in sensory ataxiaLoss of position/vibration senseDifficulty with fine motor skills

History

  • A careful history is essential since gait changes may be caused by pain, weakness, lightheadedness, vertigo, or incoordination
  • Onset:Hours-days: AcuteWeeks-months: SubacuteMonths-years: Chronic
  • Symmetric or focal symptoms
  • Presence of fever, mental status changes, weakness, sensory loss, or urinary incontinence
  • Recent viral illness or immunizations
  • History of trauma or toxic ingestion
  • Family history of movement disorder

Physical Exam

  • Perform a complete physical exam, including neurological and gait testing
  • Assess for signs or symptoms of acute, life-threatening disorders such as hemorrhage, stroke, or CNS infection:Altered mental statusHeadacheFocal neurological deficitsElevated intracranial pressure:Bradycardia, HTN, abnormal respiratory patternPapilledemaBulging fontanellesFeverMeningismusNystagmusNausea/vomitingExamine ears and perform provocative testing for nystagmus (Dix-Hallpike)
  • Note the presence of intoxication or toxidromes in patients with suspected ingestion

Essential Workup

A detailed history and physical exam will help determine which tests are necessary

Diagnosis Tests & Interpretation

Lab

  • Blood glucose level
  • Serum electrolytes
  • Toxicology screen:Standard panels may not include the drugs of interest in the ataxic patient
  • Thyroid function testing
  • Target additional testing to likely exposures, such as anticonvulsants

Imaging

  • CT:Head CT can identify mass, hemorrhage, subacute infarct, or hydrocephalusConsider CT with and without IV contrast if mass suspectedCT angiography can be performed to evaluate for vascular disease
  • MRI:Excellent study to evaluate for acute ischemia, mass, demyelinating lesions, and vascular abnormalitiesSuperior for imaging the posterior fossaMR angiography of head/neck may be indicated if vascular abnormality is suspected
  • EKG:Not indicated as part of ataxia workup, but may be useful in evaluation of nonspecific dizziness

Diagnostic Procedures/Surgery

  • Lumbar puncture:Indicated if infection or Guillain-Barr © suspected

Differential Diagnosis

  • Acute symmetric ataxia:Head traumaDrug use/toxic ingestion:AlcoholLithiumPhenytoinBarbituratesCarbamazepinePhenobarbitalValproic acidBenzodiazepinesDiphenhydramineDextromethorphanAcute viral cerebellitisMeningitis/encephalitisHydrocephalusPostinfectious syndromeHypoglycemiaHyponatremiaSevere heat stroke
  • Acute focal ataxia:Posterior circulation infarctionAnterior cerebral artery syndromeVertebrobasilar insufficiency (VBI)Cerebellar hemorrhageSubdural hematomaCerebellar abscessAcute disseminated encephalomyelitisComplicated migraineAtypical seizure
  • Subacute symmetric ataxia:Drug use/toxic ingestion:MercuryLeadHydrocarbonsGlue sniffingCytotoxic chemotherapyOrganophosphatesVitamin B1 or B12 deficiencyParaneoplastic syndromes:Breast/ovarian cancerHodgkin lymphomaNeuroblastomaLyme diseaseToxoplasmosisCreutzfeldt-Jakob disease
  • Subacute focal ataxia:Cerebellar gliomaMetastatic tumorsLymphomaMultiple sclerosisGuillain-Barr © syndromeAIDS-related progressive multifocal leukoencephalopathySyringomyeliaCervical spondylosis
  • Chronic ataxia:Alcohol-related cerebellar degenerationStable gliosisInherited disorders:Spinocerebellar ataxiasFriedreich ataxiaAtaxia telangiectasiaNiemann-Pick diseaseHypothyroidismVitamin E deficiencyTabes dorsalisCongenital malformation:Arnold-ChiariDandy-Walker
  • Disease states that cause peripheral vertigo can mimic the gait findings in ataxia:Benign paroxysmal positional vertigoAcute labyrinthitisM ©ni ©re disease
  • May present with a refusal to walk
  • Acute ataxia in children is usually a benign, self-limited process:60% of cases caused by acute cerebellar ataxia or drug ingestion
  • Acute cerebellar ataxia:Postinfectious cerebellar demyelinationUsually occurs in children 2-5 yr oldOnset 1-3 wk after triggering illnessOver 1/4 of cases occur after varicella, but linked to many viral infections and immunizationsNormal mental statusNo fever, focal deficits, or seizuresMild cases may be managed at home, but require injury prevention counselingMost children recover completely within 3 mo without intervention
  • Drug/toxic ingestions:Expect mental status changesAssess access to medications and order appropriate toxicological testing
  • Guillain-Barr © syndrome:15% present with sensory ataxiaMiller-Fisher variant: Clinical triad of ataxia, areflexia, and ophthalmoplegia
  • Neoplasm:More than 50% of childhood brain tumors occur in the brainstem or cerebellumOpsoclonus-myoclonus-ataxia syndrome:Paraneoplastic autoimmune syndrome affecting cerebellumOver 50% due to neuroblastoma
  • Stroke:Rare in children, but can occur in patients with sickle cell disease or hypercoagulable states
  • Gait disorders in the elderly are often multifactorial
  • Underlying cognitive deficits may make it difficult to distinguish presyncope, weakness, vertigo, and incoordination
  • Posterior circulation cerebrovascular syndromes, like VBI and stroke, are more common in the elderly and may present with vague symptoms, like dizziness
  • Evaluate for signs of orthostasis or extrapyramidal disorders, like Parkinsonism

Treatment

Pre-Hospital

  • Acute onset of ataxia may be due to stroke or hemorrhage
  • Deterioration in mental status may warrant field endotracheal intubation

Initial Stabilization/Therapy

  • ABCs
  • IV access
  • Supplemental oxygen
  • Cardiac monitor
  • Fingerstick blood glucose:Administer dextrose if hypoglycemicConsider thiamine in alcoholics and malnourished patients

Ed Treatment/Procedures

  • Institute fall precautions
  • Treatment must be tailored to the patients presentation and underlying pathology
  • Cerebellar infarction can lead to significant edema with mass effect and herniation:Neurosurgery consultation may be needed for decompressive craniectomy

Medication

  • Dextrose: D50W 1 amp (50 mL or 25 g) (peds: D25W 2-4 mL/kg) IV
  • Thiamine (vitamin B1): 100 mg IV

Follow-Up

Disposition

Admission Criteria

  • Acute and subacute ataxia, particularly if a benign etiology cannot be established
  • Patients who cannot ambulate safely
  • Admit patients with cerebellar hemorrhage or mass effect to the ICU

Discharge Criteria

  • Reversible or mild symptoms
  • Normal mental status
  • Able to ambulate safely

Followup Recommendations

Follow up with primary care or neurology depending on likely etiology of symptoms

Pearls and Pitfalls

  • Failure to distinguish true ataxia from other causes of gait instability
  • Failure to note trauma in intoxicated patients
  • Failure to realize the limitations of CT scan in evaluating the posterior fossa
  • Failure to recognize the risk of herniation in cerebellar lesions, including stroke

Additional Reading

  • Friday JH. Ataxia. In: Fleisher GR, Ludwig S, Henretig FM, et al., eds. Textbook of Pediatric Emergency Medicine. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:189-192.
  • Manto M, Marmalino D. Cerebellar ataxias. Curr Opin Neurol. 2009;22:419-429.
  • Mariotti C, Fancellu R, Di Donato S. An overview of the patient with ataxia. J Neurol. 2005;252:511-518.
  • Savitz SI, Caplan LR. Vertebrobasilar disease. N Engl J Med. 2005;352(25):2618-2626.

Codes

ICD9

  • 334.2 Primary cerebellar degeneration
  • 334.3 Other cerebellar ataxia
  • 781.3 Lack of coordination
  • 334.0 Friedreichs ataxia

ICD10

  • G11.1 Early-onset cerebellar ataxia
  • G11.9 Hereditary ataxia, unspecified
  • R27.0 Ataxia, unspecified
  • R26.0 Ataxic gait

SNOMED

  • 20262006 Ataxia (finding)
  • 250067008 Truncal ataxia (finding)
  • 230227009 Early onset cerebellar ataxia (disorder)
  • 10394003 Friedreichs ataxia (disorder)