Evaluation of the Dizzy Patient


Timothy C. Hain, MD

This material is intended for practicing physicians specializing in otology or neurology. It has been used in numerous CME lectures. Hyperlinks are given to other material that expands upon this outline.

Please read our disclaimer.


THE DIZZINESS PROBLEM

  1. Dizziness is the primary complaint in 2.5% all primary care visits = 8 million/year visits (Sloan). Practically, there are far more patients with dizziness/ataxia than there are doctors with an interest in caring for them.
  2. There are substantial otologic (40-50%), neurologic (10-30%), general medical (10-30%), and psychiatric/undiagnosed causes of vertigo (15-50%).
  3. Dizziness presents a significant sorting problem. Because of the diverse causes, patients prefer a "symptom" oriented setting (i.e. a dizzy clinic) to a "cause" oriented setting (i.e. sequential visits and testing in an ENT, Neurology, Cardiology, or Psychiatry subspecialty setting).

SURVEY OF CAUSES OF DIZZINESS:

  1. Otologic causes(about 50% of vertigo in otology settings, e.g. see Nedzelski reference)
    1. Physiology
      1. Canals register head velocity
      2. Otoliths register linear acceleration
      3. Together provide input to two central reflexes, VOR (Vestibulo-Ocular reflex) and VSR (Vestibulo-Spinal Reflex)
    2. Three patterns of Injury
      1. Asymmetrical (Vertigo and "listing")
      2. Symmetrical (Oscillopsia and ataxia)
      3. Cross-coupling (positional vertigo, pressure sensitivity, Tullio's phenomenon)
    3. Most common types of otologic dizziness
      1. Asymmetrical dysfunction:
        1. Vestibular Neuronitis - monophasic illness without hearing disturbance.
        2. Meniere's disease - episodic hearing disturbance and dizziness
      2. Symmetrical dysfunction
        1. Ototoxins - look like midline cerebellar disease. Diagnosis often has medicolegal implications.
        2. Bilateral forms of unilateral diseases such as vestibular neuritis can cause similar symptoms.
      3. Crosscoupling
        1. Benign Paroxysmal Positional Vertigo (BPPV) - About 20% of all patients, the most important type of vertigo to recognize.
        2. Perilymph fistula and SCD (superior canal dehiscence sydrome)-- rare form of vertigo where internal or external pressure changes or sound induce vertigo (Tullio's phenomenon).
        3. Rarely central vertigo causes cross-coupled caloric or head-shaking nystagmus. In this context it may be called "perverted" nystagmus.
    4. Neurological Dizziness - 10-30% of all vertigo in neurological settings,(Drachman and Hart, 1972; author's material, 1992), about 5% of vertigo everywhere else.
      1. Physiology: Vestibular nucleus in brainstem gets information from eyes, ears, joints. It resolves contradictions/ambiguities (somatosensory integration), and produces output to drive VOR and VSR reflexes. Some somatosensory integration may also occur in the spinal cord. Repair/readjustment of these reflexes is an ongoing process. Much repair is mediated by the cerebellum, but repair processes also include local recovery of neuronal circuitry and cognitive adjustments. Cerebellar injuries are particularly bad because CNS may be unable to repair an injury, or repair process gone amok may contribute to disability.
      2. General features: Central vertigo is slower to recover than otologic causes of vertigo. It is usually relatively unaffected by sensory input. There may be obvious mismatches between nystagmus and vegetative symptoms (i.e. headaches, nausea, fatigue).
      3. Most common types: Sites of injury include the vestibular nucleus and the cerebellum.
        1. Vertebrobasilar insufficiency and stroke - most common
        2. Multisensory Disequilibrium -- important cause of ataxia in elderly.
        3. Migraine - about 10% of central vertigo
        4. Cervical "Vertigo" - very uncommon.
        5. Low CSF pressure syndrome (post-LP, CSF leak) -- can resemble symptoms of Meniere's disease because tinnitus is common.
    5. General Medical Problems - only about 5% of specialty clinics, but 30% of ER diagnoses (ER: Madlon-Kay)
      1. Blood Pressure/Arrhythmia (syncope, orthostatic hypotension, cardiac arrythmia and angina with prominent blood pressure effects)
      2. Hypoglycemia (diabetics, people who don't eat regularly)
      3. Medication (mainly antihypertensives and vasodilators)
      4. Infection (ER mainly, gastroenteritis, pneumonia, UTI, middle ear)
      5. B12 deficiency -- About 10% of 80 year olds have B12 deficiency. A cause of ataxia.
    6. Unlocalized causes of dizziness 35-50% of vertigo (Madlon-Kay, Nedzelski, Drachman-Hart, Kroenke).
      1. Psychiatric -- in the dizzy patient, the diagnosis of psychiatric disease is often made by otolaryngologists. Authors view is that while psychogenic dizziness clearly does exist, in many cases it is just a variant of unknown. The frequency of this diagnosis varies very substantially between authors (15% -- for "dizzy" doctors, 50% is typical for ER settings, for subspecialty clinics that do not consider entire spectrum of diagnoses (i.e. Nedzelski et al) and in family practice settings (e.g. Kroenke et al)). Anxiety and Panic are most common recognizable entities. School avoidance is seen in aldolescents. Somatization syndrome, anxiety and malingering occurs in young adults and middle aged. Depression equivalent and anxiety is more common in elders.
      2. Hyperventilation -- this diagnosis also varies dramatically between series. Authors view is also that it is usually just a variant of unknown. Other authors view it as a variant of anxiety.
      3. Unknown -- Again this diagnosis varies substantially between series. It is the single most common diagnosis in the ER (probably because they only have one shot at making the diagnosis).

    HISTORY OF THE DIZZY PATIENT

    1. History is frequently more important than the examination. For example, one can usually easily spot BPPV through history (about 20% of dizzy patients). This allows you to focus a comprehensive lengthy examination. A questionnaire is very helpful.
      1. Define: patient's dizziness: Vertigo, Impulsion, lightheaded, oscillopsia, ataxia, confusion.
      2. Timing: (BPPV-seconds, TIA-minutes, Menieres-hours, Vestibular Neuronitis-Days, Ototoxins-years). See Hain, 1997 reference for more detail about timing categories.
      3. Associations: head motion or change in head position, hearing disturbance, headache, cognitive symptoms, relation to stress.
      4. Review of systems: especially vascular risk factors and ear surgery.
      5. Family History: Similar disorder ? Migraine
      6. Medication History: present and past exposures to ototoxins, antihypertensives.
      7. Previous studies

    Examination of the Dizzy Patient

    1. General Medical Examination -- rarely helpful
      1. Blood pressure - Orthostatic changes in blood pressure or pulse, Hypertensive ?
      2. Cardiac - arrhythmia, murmur, bruit ? (arrhythmia's are most common source of dizziness in persons with cardiac disorders)
    2. Ophthalmological examination
      1. Ophthalmoscopic - Papilloedema ? Hypertensive changes ?
      2. Oculomotor examination
        1. Nystagmus (saccadic, vestibular, pendular, congenital, alternating)
        2. Saccades, pursuit, vergence, gaze
    3. Otologic Examination
      1. Hearing -- often helpful
      2. Inspect tympanic membranes -- rarely helpful
      3. Be prepared to remove wax
    4. Neurological Examination -- rarely productive but should be done for safety
      1. Cranial nerves, especially 7
      2. Motor power and reflexes, pathological reflexes (e.g. Babinski)
      3. Sensory (proprioception)
      4. Cerebellar signs - finger to nose, tandem gait.
      5. Gait and Station (Timed Tandem Romberg (TTR), cerebellar ataxia, Parkinsonian, functional)
    5. Vestibular Examination -- generally very helpful in making diagnosis
      1. a. Spontaneous nystagmus is most helpful for diagnosing Meniere's disease, Vestibular Neuronitis, central disorders, to rule out Psychiatric.
        1. Frenzel's goggles - Extremely useful. A video system which occludes vision is best.
        2. Ophthalmoscope test - a poor substitute for Frenzel
      2. Fixation Suppression -- modestly helpful when it is poor, but this is rarely encountered. Pursuit deficiencies in otherwise normal elderly adults make this test useless in persons over the age of 60.
        1. Peripheral vestibular - good suppression unless very strong nystagmus
        2. Central vestibular - suppression varies. If weak nystagmus and no suppression, likely central.
      3. VOR asymmetry is most helpful for diagnosing vestibular neuritis, acoustics, and to rule out psychiatric disturbance
        1. Head-shake test - (Hain et al, 1987). Helpful when done properly. Is not 100% sensitive and suggests the wrong side about 1/4 of the time.
        2. Minimal caloric - (Nelson, 1969). Rarely use because too time consuming.
        3. Rapid Dolls - (Halmagyi, 1988; Harvey and Wood, 1996). Occasionally helpful -- sensitivity is about 40%.
        4. Vibration of the sternocleidomastoids with video frenzels -- sensitivity is nearly 100% to unilateral vestibular loss.
      4. VOR gain is most helpful for diagnosing ototoxicity and other bilateral vestibulopathies
        1. Dynamic illegible 'E' test or DIE (Longridge, 87). Very helpful.
        2. Ophthalmoscope test (Zee, 78). Not always positive when DIE is positive.
      5. Special maneuvers are helpful for diagnosing BPPV (20% all vertigo), Fistula, Syncope, Hyperventilation test
        1. Dix-Hallpike - EXTREMELY IMPORTANT.
        2. Fistula Test - subjective most practical. Occasionally helpful.
        3. Hyperventilation test - 30 seconds, look for nystagmus. Rarely helpful.
        4. Carotid Sinus Compression - for syncope patients. Reluctant to do routinely.

    FORMULATING YOUR IMPRESSION

    Think of this as a sorting or matching process, not as a decision tree. Diagnoses fall through the sorting sieve. Decision trees are prone to error as a wrong fork may lead one into a blind alley. Regroup if treatment is not successful and back up.

    1. Diagnoses directly based on the examination-- includes general medical.
      1. BPPV - Positive Dix/Hallpike
      2. Fistula or related syndrome - Pressure sensitivity
      3. Ototoxicity - Fails dynamic illegible E test and Tandem Romberg test
      4. Cardiac problems - blood pressure/arrhythmia/carotid sinus sensitivity
      5. Multisensory - significant deficit in visual/somatosensory function
      6. Hyperventilation - reproduces symptoms, no other exam positives. Be careful here, because acoustics and multiple sclerosis may have substantial HVT sensitivity.
    2. Other peripheral vestibular problems - positives on vestibular tests. Vestibular Neuritis/Labyrinthitis, Meniere's. ENG, audiometry and ECOG tests are often useful in this group.
    3. Neurological problem - central pattern history or exam. Stroke, sensory ataxia, cerebellar ataxia, migraine, nystagmus. MRI single most useful test. EEG if paroxysmal quality. Medication trials often helpful for migraine/seizure.
    4. Psychiatric problems - normal or inconsistent exam, history. Agoraphobia, panic attacks, depression, malingering. Consider psychiatric referral. A trial of benzodiazepines or SSRI medications may be helpful to, although they may also help in non-psychiatric dizziness.
    5. Other medical problems -- rarely gastritis causes nausea, etc.
    6. Unknown cause - nonspecific exam/history. This may be a substantial group, especially if you are not very confident about pattern recognition. At this point it may be helpful to regroup and sort patients based on timing (see Hain, 1997 in reference list).

    References

    1. Drachman D, Hart CW. Neurology 1972, 22, 323-334 (Classic article on sorting)
    2. Hain TC, Fetter M, Zee DS. Am J Otol, 8:36-47, 1987 (Head-shaking Nystagmus )
    3. Hain TC. Approach to the Dizzy patient in Practical Neurology (Ed. J. Biller), 1997. This reference gives more detail about the approach outlined here.
    4. Halmagyi GM, Curthoys IS. Arch Neurol 45:737-740, 1988 (Rapid Dolls)
    5. Harvey SA, Wood DJ. The oculocephaic response in the evaluation of the dizzy patient. Laryngoscope 106:6-9, 1996
    6. Kroenke K et al. Ann Int Med, 117, 898-904, 1992 (Psychiatric)
    7. Longridge NS, Mallinson AI. The dynamic illegible E (DIE) test: a simple technique for assessing the ability of the vestibulo-ocular reflex to overcome vestibular pathology. J Otolaryngol 1987;16:97-103, Acta Otol (Stockh) 103: 273-279, 1987; Otolarygol HNS 1984:92:671-7
    8. Madlon-Kay DJ. J. Family Practice, 21, 109-113, 1985 (ER)
    9. Nedzelski et al. Otolaryngol 1986: 15: 101-104 (Otology setting)
    10. Nelson JR. Neurology 19: 577, 1969 (Neurology setting)
    11. Zee DS. Ann Neurol 3: 373, 1978 (Ophthalmoscope test)
    12. Lanska DJ, Goetz CG, Romberg's sign. Development, adoption, and adaptation in the 19th century. Neurology 2000:55:1201-1206

    Self-Test questions:

    (True/False)

    1. Most dizziness originates from inner ear disturbances

    2. In the Dix/Hallpike Maneuver one expects to see a nystagmus which has both vertical and rotatory components


    Answers:

    1. False
    2. True