1. Inner Ear Case Med 6573: Nervous System University of Minnesota Medical School Duluth 16 and 19 February 2007 Drs. Nordehn, Forbes & Fitzakerley Mr. Rodney Mott is a 46-year-old carpenter, who has trouble hearing and some problems with dizziness.

2. YOU MUST PREPARE PRIOR TO THE SESSION ON FRIDAY, FEBRUARY 16 2007, 9:00 A.M. 1.Review the information provided in this handout relative to Mr. Mott’s present and past history, and your physical exam findings. Note significant data Be prepared to discuss the case 2.Evaluate what you know about Mr. Mott relative to the “Questions for Evaluating Hearing Loss” presented in the Isaacson and Vora article “Differential Diagnosis and Treatment of Hearing Loss”. 3.Answer the questions that are posed on slides 6 and 9 and be prepared to discuss them.

3. History of Present Illness first noticed that he had trouble hearing his teakettle osometimes he hears whistling in his ears that is not the teakettle oat other times, he can’t hear the kettle when it whistles othis has been going on for several months, getting gradually worse in both ears, although the sounds seem louder in his left ear about 3 months ago, while getting out of bed, he heard whistling in his ears that became progressively louder - at the point where it was becoming annoying, he suddenly felt the room spin ositting down gave him no relief ohe became nauseated and eventually vomited obecause the spinning persisted, he climbed back into bed and found himself to be more comfortable when he lay on his right side with his eyes open owithin one half hour the spinning had stopped and the whistling also diminished he has had several similar episodes since then oeach begins with increasing whistling followed by the spinning sensation between his attacks, he feels quite well and has no difficulty with his strength and coordination

4. Past Medical History usual childhood illnesses no history of heart disease, diabetes, stroke, convulsions or hypertension approximately 5 years ago, he was hospitalized for severe burns on his hands and forearms ohe remembers being told that the IV he was given contained antibiotics three years ago, he suffered a blow to the head while playing volleyball, lost consciousness for a few minutes but was not seen by a physician he has a history of his hands and feet "feeling puffy", so he has been using his neighbor's “water pills" (furosemide?) for a couple of years to treat this himself

5. Habits and Social History Habits smokes one half pack per day since the age of 20 and has not tried to quit drinks one to two beers at dinnertime three to four times per week, but not hard liquor does not use street drugs Social History divorced 12 years ago works as a carpenter (self-employed) he has one older brother who has had some hearing problems, but he has no details about his brother’s condition his parents are both alive and have had no serious medical problems he graduated from high school at age 18, and is happy in his work

6. What are the important problems that Mr. Mott is having? Be specific. What are the potential causes of these problems? What aspects of his history might have contributed to the problems that Mr. Mott is having? What part(s) of the nervous system is(are) involved and why?

7. Physical Examination Findings General Appearance Mr. Mott is a 46-year-old white male in no apparent distress. Vital Signs Height = 198 cm; Weight = 89.3 kg Temperature = 37.0 °C (oral) Heart rate = 70 beats/min Blood pressure = 100/60 mmHg (Sitting) Respiratory rate = 14 breaths/min Oxygen saturation = 97% Lungs, CV, Abdomen: Normal Neurological Exam: Normal with the exception of VIII (see next slide)

8. Physical Examination Findings HEENT Eyes: Pupils equal, round and reactive to light (PERRL), Extra ocular movements intact (EOMI), no nystagmus and optical disks sharp Neck: Trachea in midline. Thyroid normal size. No lymphadenopathy. Mouth: Oral mucous membranes pink and normal hydration. Ears: Tympanic membranes visualized and clear, pearly gray. Rinne test-normal (air >bone) bilateral. Weber abnormal (lateralizes to right). Hearing loss with marginal loss of speech discrimination. Unable to hear the tick of a watch in both ears.

9. Near the end of the physical examination, Mr. Mott noted that the whistling in his ears was increasing and he had a mild attack of spinning sensation. He felt nauseated but did not vomit. During the attack, he developed a rightward nystagmus. The spinning, whistling and nystagmus lasted about 10 minutes. Identify the abnormal and pertinent normal findings on the physical examination.

10. Audiometry

12. A B D C Otoacoustic Emissions Test

13. Interpret the procedural findings (audiometry, radiology report and otoacoustic emissions) in the context of Mr. Mott’s case. What is your diagnosis?

14. Faculty Learning Issues Describe the components and physiology of the vestibulo- ocular reflex, and relate these components to the evaluation of nystagmus. Distinguish among conductive and sensorineural hearing loss and central auditory processing disorders. Define how each type of hearing loss would alter the patient’s audiogram from normal. Describe the physiological basis for and the interpretation of: Rinne and Weber tests, audiometric testing, otoacoustic emission and ABR testing. List risk factors for hearing loss and vertigo that should be identified during history taking and/or evaluated during the physical exam.