Testing Vestibular Function
Testing Vestibular Function ➢ Four percent of patients18-65 yo visit PCP with complaint of “dizziness” ➢ Three percent consider it “Severely incapacitating” ➢ Third most common complaint in elderly
Testing Vestibular Function ➢ Otolaryngologist is considered balance specialist ➢ Often PCP for dizzy patients ➢ Private practice physicians often quoted “I wish I knew more about dizzy patients
Objectives ➢ Describe office examinations of dizzy patients ➢ Describe vestibular function studies ➢ Review indications for vestibular function studies ➢ Review efficacy of office and vestibular function studies
Office Examination of the Dizzy Patient ➢ Dix-Hallpike Maneuver ⚫ Used to provoke nystagmus and vertigo commonly associated with BPPV ⚫ Head turned 45 degrees to maximally stimulate posterior semicircular canal ⚫ Head supported and rapidly placed into head hanging position ⚫ Frenzel glasses eliminate visual fixation suppression of response
Dix-Hallpike Maneuver
Dix-Hallpike Maneuver ➢ Positive test ⚫ Up-beating nystagmus ⚫ Nystagmus to the stimulated side ⚫ Rotary component to the affected ear ⚫ Lasts 15-45 seconds ⚫ Latency of 2-15 seconds ⚫ Fatigues easily
Pneumatic Otoscopy ➢ Positive and negative pressure applied to middle ear ➢ Hennebert’s sign/symptom – nystagmus and vertigo with pressure, alternates with positive and negative pressure ➢ Can be present in patients with perilymphatic fistula, syphilis, Meninere’s disease, SCC dehiscence syndrome
Head Shake Nystagmus ➢ Evaluates unilateral vestibular weakness ➢ Head tilted back 30 degrees ➢ Shake back and forth for 30 seconds as quickly as possible ➢ Unilateral vestibular deficit causes slow phase nystagmus to the side of lesion ➢ Low sensitivity (27%) ➢ Good specificity (85%)
Head Thrust Test ➢ Inhibitory response not as robust as the stimulatory response to stimulate VOR ➢ Movements that overcome the inhibitory response of vestibule will result in VOR lag ➢ Head tilted 30 degrees ➢ Rapid head movements to either side with focus on examiner’s nose ➢ Patients have catch-up saccade when rotated to side of weakness ➢ Sensitivity 75%, Specificity of 85%