Ataxia and Dizziness Jesse Sturm, MD Pediatric Fellow’s Conference June 25, 2008

Outline  Definitions  Ataxia  Causes  Workup – labs and specific exam findings  Dizziness  Causes  Algorithmic approach  Conclusion

Definitions  Ataxia: disturbance in smooth accurate coordination of movements, unsteady gait  Dizziness: non specific term  Includes vertigo, disequilibrium, pre-syncope  Vertigo – symptom of illusory movement, sense of swaying or tilting  Some perceive self-movement, others perceive motion of the environment  Due to asymmetry in vestibular system (labyrinth, central structures in brainstem)  Vertigo is a symptom, not a diagnosis

Ataxia  Ataxia: ataktos – “lacking order” (Greek)  Disturbance in smooth accurate movements – commonly unsteady gait  Often result of cerebellar dysfunction  Disturbance at multiple sensory levels can affect coordination  i.e. loss of proprioception = sensory ataxia  Acute ataxia is rare, most often benign presenting complaint

Cerebellum  A: midbrain  B: pons  C: medulla  D: spinal cord  E: 4 th ventricle  G: tonsil  H: ant lobe  I: post lobe

Cerebellum  Vermis - midline  dysarthria  truncal titubation  symmetric ataxia  Hemispheres  ipsilateral limb dysmetria  hypotonia  tremor  ataxia in direction of affected hemisphere

Causes of Ataxia  Review of 80 admitted pediatric cases:  80% of acute ataxias had diagnosis of acute cerebellar ataxia, toxic ingestion, Guillaine- Barre syndrome Gieron-Korthals, MA. Acute ataxia in childhood: a 10-year experience. J. Child Neurology 1994: 9:381.

Differential of Acute Ataxia Infectious/immune mediated disorders Acute cerebellar ataxia ADEM Systemic infections Brainstem encephalitis Multiple Sclerosis Toxic: alcohol and drug related Mass lesions Tumor Vascular lesions AbscessesHydrocephalusTrauma Cerebellar contusion or hemorrhage Posterior fossa hematoma Post-concussion syndrome Vertebrobasilar dissection Stroke Vertebrobasilar dissection or thromboembolism Cerebellar hemorrhage Paraneoplastic disorders Opsoclonus-myoclunus syndrome Sensory ataxia Guillain-Barre syndrome Miller Fisher syndrome Paretic ataxia Upper motor neuron syndrome Lesions of frontal lobe Lesions of frontal lobe Lower motor neuron syndrome Spinal cord Spinal cord transverse myelitis, cord compression transverse myelitis, cord compression Peripheral nerve Peripheral nerve GBS, MF, tick paralysis GBS, MF, tick paralysis Inborn errors of metabolism Basilar Migraines Non-convulsive seizures Wernicke’s encephalopathy

Causes of Acute Ataxia  Life threatening conditions  Tumors, Stroke, Infection  Common conditions  Acute cerebellar ataxia, GBS, Labyrinthitis, Toxins, Migraine syndromes, Trauma  Rare disorders

Causes of Acute Ataxia  Life threatening conditions  Tumors, Stroke, Infection  Common conditions  Acute cerebellar ataxia, GBS, Labyrinthitis, Toxins, Migrane syndromes, Trauma  Rare disorders

Ataxia - Tumors  45-60% of all childhood brain tumors arise in brainstem or cerebellum  Can present with progressive ataxia  Symptoms of increased ICP  Papilledema, cranial neuropathies, HA, emesis  Rarely midline supratentorial tumors  Opsoclonus-Myoclonus (rapid dancing eye movements and rhythmic jerking)  Paraneoplastic - neuroblastoma in up to 50%

Ataxia - Stroke  Hemmorhage into cerebellum or posterior fossa from trauma or vascular malformation  Vertebral or basilar artery disease  Sickle cell  Hypercoagulable states  Vertebrobasilar artery dissection following neck dissection following neck injury can present as injury can present as acute ataxia acute ataxia

Ataxia - Infection  Cerebellar abscesses – contiguous spread from ASOM or mastoiditis  Ataxia/fever +/- signs of increased ICP  Brainstem encephalitis  CNeuropathies, AMS, seizures  Causes: listeria, lyme disease, EBV, HSV  CSF pleocytosis  Acute post-infectious demyelinating encephalomyelitis (ADEM), multiple sclerosis  Seizures, CNeuropathies, weakness, sensory deficits, transverse myelitis

Causes of Acute Ataxia  Life threatening conditions  Tumors, Stroke, Infection  Common conditions  Acute cerebellar ataxia, GBS, Labyrinthitis, Toxins, Migrane syndromes, Trauma  Rare disorders

Acute Cerebellar Ataxia (ACA)  Post infectious cerebellar demyelination and/or direct cerebellar infection (seen on MRI)  35% of acute childhood ataxia  Autoimmune phenomena against cerebellar epitopes  Onset 5-10 days after precipitating infection (70%)  Peak age 2-4yo (case series ages 1.5yo – 12.5yo)  Symptoms maximal at onset  Truncal ataxia severe, extremity ataxia < trunk  Seen in sitting position  Vomiting, horizontal nystagmus, dysarthria may occur  Mental status normal, no fever, no meningismus

Acute Cerebellar Ataxia (ACA)  Most common findings on exam are nystagmus and dysmetria (50%)  Small retrospective study (n=39):  Mean CSF WBC 16 (0-40)  >5 WBC in 48%, all with lymph predominance  Mean CSF protein 20 (>40 in 23%)  CT done in 14 patients, all normal  Recent studies show + MRI findings in classic ACA

Acute Cerebellar Ataxia (ACA)  Varicella implicated in >25% cases  Rare cases due to VZV vaccine  Echovirus, EBV, Measles, Mumps, HSV, Parvovirus  MMR vaccine implicated in rare cases

Acute Cerebellar Ataxia (ACA)  Symptoms take several weeks to resolve  Mean ~ 1.5 weeks  Complete recovery in >90% patients  Ataxia symmetric  Findings in cerebellar ataxia remain unchanged whether eyes open or closed  No evidence that immunosupressive therapies improve outcomes

Acute Cerebellar Ataxia (ACA)  Clinical features do not distinguish from other causes of acute ataxia  Diagnosis of exclusion

Ataxia - Guillain-Barre Syndrome  Ascending paralysis, areflexia, progressive  15% of children with GBS also lose sensory input to cerebellum --- develop sensory ataxia  + Romberg, dec DTR  Miller Fisher syndrome: GBS with triad of ataxia, areflexia, opthalmoplegia

Ataxia - Labyrinthitis  Inflammation of vestibular apparatus  Bacterial or viral  Symptoms of hearing loss, vomiting, extreme vertigo  Vertigo often exacerbated by head movements  Dix-Hallpike maneuver

Ataxia - Toxin Exposure  Responsible for up to 30% acute ataxia  Anticonvulsants – phenytoin, carbamazepine, phenobarbitol, antihistamines  Lead, carbon monoxide, inhalants, Etoh, Benzos  Usually accompanied by AMS

Ataxia - Migraine Syndromes  Basilar migraines and familial hemiplegic migraine syndromes present with ataxia  Associated headache and vomiting distinguish from other acute ataxias  Visual auras common

Ataxia - Trauma  Post concussive ataxia  Directed traumatic force to labyrinth structures  May be associated with hemotympanum and temporal fractures

Causes of Acute Ataxia  Life threatening conditions  Tumors, Stroke, Infection  Common conditions  Acute cerebellar ataxia, GBS, Labyrinthitis, Toxins, Migrane syndromes, Trauma  Rare disorders

Ataxia – Rare Causes  Tick paralysis  unsteady gait, ascending paralysis/weakness, areflexia  neurotoxin in tick saliva  Hypoglycemia  Seizure disorder  simple non-convulsive seizures may manifest as ataxia alone  Conversion disorder  narrow gait, elaborate near falls  Inborn error metabolism  Urea cycle, aminoacidopathies (MSUD), organics acidemias  Congenital anomolies  Chiari malformation, encephaloceles, cerebellar aplasia/hypoplasia  Genetic conditions  ataxia telangectasia etc.

Diagnostic workup  Temporal course  Acute, episodic, chronic  Associated neurological findings  History  PE  Targeted diagnostic workup workup

Ataxia – Temporal Course  Rapid onset: traumatic, infectious or post- infectious, or toxic etiology  Progressive onset (few days): metabolic syndromes, GBS  Insidious onset (days to weeks): brainstem and cerebellar tumors

History  Recent infection, vaccination  Previous episode of ataxia  Migraine-related syndrome, seizure, IEM  Family history  Migraine syndromes, hereditary ataxias, IEM

Concurrent Symptoms  Otalgia, vertigo, vomiting  Suggest labyrinthitis, often see nystagmus  Recurrent headaches, behavior changes  May represent increased ICP  Abnormal mental status  Mass lesions, CNS infection, toxin exposure, trauma (head/neck), stroke, inborn error metabolism  Access to drugs of abuse, ethanol, anticonvulsants

Physical Exam  Vitals: bradycardia, HTN, resp pattern, fever  Anterior fontanelle  Ipsilateral head tilt (posterior fossa tumor)  Papilledema  Nystagmus (vestibular, cerebellar, brainstem disorder)  Opsoclonus (occult neuroblastoma)  AOM, hearing loss +/- vomiting/vertigo (acute labyrinthitis)  Meningismus  Healing rash/viral exanthem  Tick attachment

Neurologic Exam  General mental status  AMS suggests ADEM, CNS infection, stroke, ingestion  Cranial neuropathies  Suggest posterior fossa lesion, encephalitis, GBS with MFS  Motor exam  “paretic ataxia” -if weak may stagger to compensate  GBS, Botulism, transverse myelitis, myasthenia, tick paralysis  Check reflexes, strength  Sensory exam  Proprioceptive input may cause ataxia (seen in GBS)  Romberg test – when close eyes remove visual compensation  Cerebellar exam  May be normal even with specific lesions

Cerebellar Exam  Gait, Speech, Coordination i.e. DRUNK  Gait – wide based, unsteady, lurching  Titubation – difficulty with truncal position  Speech – clarity, rhythm, tone, volume  Coordination – over/undershooting on FTN, difficulty with RAM (dysdiadochokinesia)

Diagnostic Testing  Toxicology Screen  Drug of abuse, specific drug levels  35% of UDS were + in one retrospective series in children (n=90) (Gieron-Korthals, 1994), HIGHEST YIELD  Glucose  Metabolic Evaluation  Especially for acute episodic ataxia to identify IEM  Serum lactate, pyruvate, amino acids, ammonia, pH  CSF examination  Rarely indicated unless clinically concerned for meningoencephalitis  Moderate protein elevation and pleocytosis occurs in 25-50% ACA, ADEM, MS, GBS  Cytoalbuminologic dissociation in GBS (high protein >40, low cells 40, low cells<10)  Neuroimaging  Prior to LP if any concern for increased ICP

Imaging  Obtain for acute ataxia with:  AMS, focal neuro signs, cranial neuropathies, asymmetry of ataxia, history of trauma, concern for mass lesion, no improvement in 1-2wks  MRI  superior for posterior fossa lesions  demyelinating disease better visualized  CT  conditions needing urgent intervention

EEG and EMG  EEG if concerned concurrent seizure  Obtain if fluctuating clinical signs  60% of children with ACA will have abnormal EEG, epileptiform activity or slowing  EMG sensitive tests for GBS (sensory ataxias), may not be helpful early in disease  EMG findings in 90%

Algorithmic Approach

Dizziness  Dizziness: non specific term  Includes vertigo, disequilibrium, pre-syncope  Vertigo – symptom of illusory movement/rotation, sense of swaying or tilting  Some perceive self-movement, others perceive motion of the environment  Due to asymmetry in vestibular system (labyrinth, central structures in brainstem)  Vertigo is a symptom, not a diagnosis

Vertigo  True vertigo  Subjective sense of rotation of environment relative to patient or patient to environment  Acute attacks often accompanied by nystagmus  Pseudovertigo  Complaints of lightheadedness, flushing, weakness, ataxia, unsteadiness, pallor, anxiety, stress, fear

True Vertigo  Disturbance of peripheral or central components of vestibular system  CN8 carries impulses to nuclei in cerebellum  Additional impulses carried to CN 3,4,6  Almost all patients have fast component of nystagmus in same direction as perceived rotation  Rare in young children, average age 10yo  Peripheral – semicircular canals and vestibule  Hearing may be impaired  Central – brainstem, cerebellum, cortex  Hearing usually spared

Vestibular System  Semicircular canals  rotation  Vestibule structures  linear acceleration

Vertigo: Common Causes  Supperative or serous labyrinthitis  Vestibular neuronitis  Benign paroxysmal vertigo  Migraine  Ingestions  Seizure  Motion sickness

Vertigo: Labyrinthitis Inflammation of David Bowie as ______ the ______ King

Vertigo: Labyrinthitis  Supperative otitis with effusion – may extend directly into labyrinth  Cholesteatoma of TM can causes fistula into labyrinth  Direct viral infections of labyrinth, w/o effusion  Vestibular neuronitis  Measles, mumps, EBV, Zoster of canal and CN7 (Ramsay-Hunt)  Resolves in 1-3 wks  Steroids shorten course

Benign Paroxsysmal Vertigo (BPV)  Considered to be form of migraine  Peaks 1-5yo  Recurrent attacks, sudden onset – emesis, pallor, sweating, nystagmus  Episodes last minutes  Mistaken for seizures  EEG normal, no altered consciousness  Disorder spontaneously resolves after 2-3 years  Distinct from benign paroxysmal positional vertigo  Short vertigo attacks from certain positional movements (adult phenomena)  Dix Hallpike maneuver

Vertigo: Migraine  Up to 19% of children have vertiginous symptoms during aura of migraine  HA pain often absent  Basilar migraines – throbbing occipital HA with brainstem dysfunction (vertigo, ataxia, tinnitus, dysarthria)

Vertigo: Ingestions  Ototoxic drugs:  Aminoglycosides, lasix, minocycline, aspirin, ethanol, anticonvulsants

Vertigo: Seizures  Vestibular seizures  Sudden onset vertigo with or without nausea, emesis, headache  Followed by period of altered consciousness  EEG abnormal  Anticonvulsants of benefit

Vertigo: Motion Sickness  Mismatch of information provided to brain by vestibular and visual systems  Occurs during periods of unfamiliar rotation and acceleration  Prevent attacks by watching environment move in direction opposite body movement  i.e. looking out window of moving car

Vertigo: Meniere’s Disease  Episodic attacks of vertigo, hearing loss, tinnitus, autonomic symptoms of pallor, nausea, emesis (1-3hrs)  Between episodes may have impaired balance  Uncommon < 10yo  Caused by overaccumulation of endolymph in labyrinth

Vertigo: Physical Exam  Nystagmus is highly specific signs for both central and peripheral vertiginous disorders  Peripheral vertigo: slow component to affected side  Central vertigo: fast component to affected side  Dix-Hallpike maneuver to stress vestibular system  Central vertigo onset of nystagmus is immediate  Peripheral onset of nystagmus delayed several seconds  Cold calorics tests integrity of peripheral vestibular system  10cc ice water into EAC with child 60º  Slow eye movement toward cold, fast movement away (COWS)  Warm water has inverse  Lack of response implies peripheral vestibular damage

Approach to True Vertigo

Conclusion  Acute childhood ataxia often benign condition requiring little workup  Asymmetry to exam, neuropathies, progressive onset more concerning  Dizziness encompasses multiple symptoms  Differentiate true vertigo from pseudovertigo  Careful physical exam with focus on cerebellar testing often uncovers diagnosis