Ataxia and Dizziness

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

2. Outline • Definitions • Ataxia • Causes • Workup – labs and specific exam findings • Dizziness • Causes • Algorithmic approach • Conclusion

3. 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

4. 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

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

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

7. 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.

8. Differential of Acute Ataxia

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

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

11. 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%

12. 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 injury can present as acute ataxia

13. 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

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

15. 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

16. 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

17. 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

18. 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

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

20. 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

21. 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

22. 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

23. 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

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

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

26. 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.

27. Diagnostic workup • Temporal course • Acute, episodic, chronic • Associated neurological findings • History • PE • Targeted diagnostic workup

28. 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

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

30. 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

31. 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

32. 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

33. 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)

34. 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<10) • Neuroimaging • Prior to LP if any concern for increased ICP

35. 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

36. 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%

37. Algorithmic Approach

38. Algorithmic Approach

40. 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

41. 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

42. 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

43. Vestibular System • Semicircular canals • rotation • Vestibule structures • linear acceleration

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

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

46. 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

47. 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

48. 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)

49. Vertigo: Ingestions • Ototoxic drugs: • Aminoglycosides, lasix, minocycline, aspirin, ethanol, anticonvulsants

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