Dizziness

Dizziness

• Nader Aldajani

Objectives

• Identify the term.
• Discuss causes.
• Differentiate between central & peripheral dizziness.
• Outline the approach.
• Discuss BPPV.
• Discuss Ménière’s Disease.

Presentations

• Spontaneous Nystagmus

• Orthostatic Hypotension

• Benign Paroxysmal Positional Vertigo (BPPV)

• Vestibular Neuritis

• Ménière’s Disease

Definitions

Dizziness

• A term describing various sensations leading to spatial disorientation.

Vertigo

• is defined as an illusion of rotational, linear or tilting movement of self or environment caused by asymmetric input to the vestibular system. Description includes(spinning, turning)

Disequilibrium

• is sensation of instability of body positions, imbalance or off-balance.

Physiology of Balance

• Balance system components:
  • Vestibular
  • Visual
  • Somatosensory

Causes of Dizziness

Peripheral Causes

• BPPV (Benign Paroxysmal Positional Vertigo).
• Ménière’s disease
• Vestibular neuronitis
• Labyrinthitis
• Perilymphatic fistula
• CPA tumor
• Otitis media
• Trauma
• Vestibulotoxic drugs
• Infections, syphilis
• Autoimmune disorders

Central Causes

• Neurologic disorders.(migraine, seizure, stroke,MS).
• Metabolic disorder.
• Vascular headache.
• Vascular causes.(vertebrobasilar insufficiency)
• Medications & intoxication.
• Infection.
• Brain tumor.

Drug Classes Causing Dizziness

• Antiepileptics: Cerebellar Toxicity
• Antihypertensives: Hypotension, Decreased CBF
• Anticoagulants: Hemorrhage in Inner ear/Brain
• Aminoglycosides & Cisplatin: Ototoxic
• Tranquilizers: CNS Depression

Central vs Peripheral Dizziness - Characteristics Comparison

• Intensity: Central (mild), Peripheral (severe)
• Imbalance: Central (severe), Peripheral (mild-moderate)
• Compensation: Central (slow), Peripheral (rapid)
• N & V: Central (variable), Peripheral (severe)
• Auditory Symptoms: Central (common), Peripheral (rare)
• Neurologic Symptoms: Central (common), Peripheral (rare)

Z #Z

Dizziness History and Examination

• History: Onset, Duration, Recurrence, Precipitating/Relieving factors, Ear symptoms, Nausea & vomiting, Headaches, Previous viral illness, Ear diseases, trauma, or surgery, Central symptoms, Cardiovascular risk factors, Endocrine system, Medications, Psychology, Premenstrual syndrome, Noise exposure, flying, diving, new eye glasses, Impact on patient, Family history.
• Physical Examination: Vital signs, Nystagmus, ENT, Hearing test, Vestibular testing, Neurologic examination, Dynamic Visual Acuity.

Fukuda Stepping Test

• Originally described by Fukuda using 100 steps on a marked floor.
• Patients are asked to step with eyes closed and hands out in front.
• Rotation by more than 45 degrees is abnormal.
• Rotation usually occurs to the side of the lesion.
• Rotation often found in asymptomatic patients.

Diagnostic Tests

1) CT Scan 2) Caloric Testing

• Is test that evaluates horizontal SCC function in each ear independently by thermal stimulation. Technique:
• in supine position, head is elevated (chin toward sternum) 30° to bring the horizontal canal into a vertical position, each ear is irrigated with cool and warm water (or air), nystagmus is recorded with eyes open and closed.
• Observe the nystagmus response by using Frenzel goggles or an infrared video system.

3) Laboratory Vestibular Tests

• Electronystagmography (ENG)
• Rotational Chair Testing
• Posturography

Indications:

• Diagnosis unclear.
• Prolonged symptoms unresponsive to conservative treatment.
• Screen for central disorders.
• Evaluate prior to surgical ablation procedures.
• Documentation of vestibular deficits.

Positive test creteria:

• Torsional, Geotropic nystagmus: Direction does not change with repeated stimulation.
• Latency : 5-15 sec.
• Duration: <1 minute.
• Fatigable.

Dix Hallpike maneuver:

• Used to provoke nystagmus and vertigo commonly associated with BPPV

• The patient is seated on the exam table with head turned 45 degrees to the side and brought rapidly into the supine position with head hanging over the table. Head supported and rapidly placed into head hanging position.

• This maneuver allows maximal stimulation of the posterior SCC.

• Frenzel glasses eliminate visual fixation suppression of response

Epley’s maneuver

Brandt-daroff habituation exercise: