Thomas S. Rees

Central auditory dysfunction may precede the onset of clinical dementia in people with probable Alzheimer's disease.

To document the prognostic significance of a central auditory speech‐processing deficit for the subsequent onset of probable Alzheimers disease.

Visual impairment and cognitive dysfunction in Alzheimer's disease.

Objective:To determine whether impaired visual acuity is associated with dementia and cognitive dysfunction in older adults.Design:Paired case-control comparisons of the relative frequencies of visual impairment in demented cases and nondemented controls. Cohort analyses of correlation between visual acuity and cognitive functioning in demented cases.Setting:Internal medicine clinics at two academically affiliated medical centers.Participants:Eighty-seven consecutively selected patients ≥65 years of age with mild-to-moderate, clinically diagnosed Alzheimer’s disease (cases) and 87 nondemented controls matched to the cases by age, sex, and education.Measurements and main results:The prevalence of visual impairment was higher in cases than in controls [unadjusted odds ratio for near-vision impairment =2.7 (95% CI=1.4, 5.2); unadjusted odds ratio for far-vision impairment =2.1 (95% CI=1.02, 4.3); odds ratios adjusted for family history of dementia, depression, number of medications, and hearing loss were 2.5 (95% CI=1.1, 10.5) for near-vision impairment and 1.9 (95% CI=0.8, 4.6) for far-vision impairment]. When further stratified by quartiles of visual acuity, no statistically significant “dose-response” relationship between vision impairment and dementia risk was observed. Among cases, the degree of visual impairment was significantly correlated with the severity of cognitive dysfunction for both near and far vision (adjusted ps<0.001).Conclusions:Visual impairment is associated with both an increased risk and an increased clinical severity of Alzheimer’s disease, but the increased risk may not be consistent with a progressive dose-response relationship. Further studies are needed to determine whether visual impairment unmasks and exacerbates the symptoms of dementia or is a marker of disease severity.

Impact of mild to moderate hearing loss on mental status testing. Comparability of standard and written Mini-Mental State Examinations

Mild to moderate hearing loss has been hypothesized to decrease performance on verbally‐administered cognitive tests as an artifact of testing. To evaluate this hypothesis, we conducted a randomized trial of a written version of the Mini‐Mental State Examination (MMSE), a cognitive screening instrument which, in its standard form, is primarily verbally administered. After baseline standard MMSE testing, 71 outpatients with Alzheimers type dementia, 39 of whom (55%) had mild to moderate hearing deficits, and 32 of whom (45%) had normal hearing, were randomly assigned to receive either a written or standard MMSE. Hearing‐impaired patients exhibited lower standard MMSE scores than hearing‐unimpaired patients at baseline (P = .005). Contrary to expectation, however, on experimental administration, written MMSE scores were somewhat lower than standard MMSE scores in hearing‐impaired patients (P not significant). Furthermore, written MMSE scores were slightly higher than standard MMSE scores in hearing‐unimpaired patients (P not significant). These results suggest that the diminished cognitive performance associated with mild to moderate hearing loss is not necessarily an artifact of cognitive testing. In addition, these results provide preliminary evidence that a written MMSE is comparable to the standard MMSE and, thus, deserves further consideration for cognitive screening of profoundly hearing‐impaired individuals.

Validity and reliability of auditory screening tests in demented and non-demented older adults.

The validity and reliability of auditory screening tests were evaluated in 34 demented and 31 non-demented elderly outpatients. In reference to an audiometric gold standard (40-dB HL bearing loss in speech frequencies), 512-Hz and 1024-Hz tuning forks, finger rub, and whispered voice tests performed well (ROC curve areas =0.82 to 0.94). Simultaneously high (>0.80) sensitivities and specificities were achievable for all these tests in demented patients. In non-demented patients, however, only the whispered voice test achieved simultaneously high specificity and sensitivity. The most accurate rule for air conduction screening audiometry was the inability to bear ≥ two of four 40-dB HL speech frequencies (sensitivity =1.0, specificity =0.75 in non-demented patients; sensitivity =0.97, specificity =0.74 in demented patients). Interobserver/test-retest reliability was generally high for tuning forks, finger rub, and whispered voice tests (range of intraclass correlation coefficients =0.38 to 0.90), and was somewhat higher in demented than in non-demented patients. These results suggest that some of the simple, traditional methods of auditory screening may have considerable validity and reliability in demented and non-demented older adults.

Placebo Effect in Tinnitus Management

Masking devices, lidocaine, and analog oral forms of lidocaine have all been reported as being effective forms of therapy to relieve tinnitus. Many studies, however, have used single-blind protocols and were possibly biased by placebo effects. To investigate the contributions of a placebo effect in clinical tinnitus studies, 25 tinnitus patients who had received a placebo injection in a previous double-blind lidocaine study were contacted on the pretense that they would receive a test dose of lidocaine; the 20 who responded were included in this study. A 5 cc bolus of placebo saline solution instead of lidocaine was then administered to each patient. Forty percent of the patients reported a change in their tinnitus following the placebo injection. The results of this study serve to point out the inherent flaws in straight clinical trials, and that the success rates achieved in such uncontrolled clinical investigations may be biased by the placebo effects.

A prospective study of hearing changes after beginning zidovudine or didanosine in HIV-1 treatment-naïve people

BackgroundWhile hearing loss in HIV-infected people after beginning nucleoside reverse transcriptase inhibitors (NRTIs) has been reported, there have been no prospective studies that measured hearing changes longitudinally in treatment-naïve HIV-infected subjects following initiation of regimens containing NRTIs. The goal of this study was to conduct a prospective assessment of the contribution of zidovudine (ZDV) and didanosine (ddI) to hearing lossMethods/designA prospective observational pilot study to determine whether ZDV or ddI, alone or in combination, are associated with sensorineural hearing loss in HIV-infected persons. Changes in hearing levels at all frequencies and in low and high frequency pure tone averages were measured at baseline, 16, and 32 weeks after initiating antiretroviral therapy.DiscussionTreatment with ZDV and ddI did not result in loss of hearing, even after taking into account noise exposure, immune status and age. The results of this prospective pilot study do not support the notion that treatment with nucleoside antiretrovirals damages hearing.

Treatment of tinnitus with intravenous lidocaine: A double-blind randomized trial

Several recent reports have suggested that intravenous (IV) lidocaine is an effective form of therapy to relieve tinnitus; however, many of these studies were not well controlled. A double-blind randomized trial to assess the effectiveness of IV lidocaine on tinnitus was conducted at the University of Washington-affiliated hospitals on a total of 50 patients. Tinnitus was evaluated before and after injection by subjective assessment and audiometric matching. Although 40% of the lidocaine group reported a decrease in tinnitus, over 30% of the lidocaine group reported increased tinnitus after administration of the drug. There was also a high incidence of side effects, including disequilibrium, slurred speech, numbness, and tingling of the extremities in the drug group. The results of the study suggest that the clinical usefulness of IV lidocaine in relieving tinnitus may be less than was previously reported.

Otologic Changes and Disorders

Hearing loss is a normal accompaniment of old age. Many specific steps can be taken to overcome the potentially devastating effects on the individual. The geriatrician should be alert to the signs of hearing impairment and assist the patient in obtaining and using appropriate rehabilitation.

Tympanometry as an aid in the diagnosis of middle ear disease. A description of a new and important procedure for the pediatric practitioner.

Department of Otolaryngology, RL-30, University of Washington, School of Medicine, Seattle, Wash. 98105. CONVENTIONAL OTOSCOPY and audiometric screening are perhaps the two procedures most widely used by pediatricians when examining for middle ear disease. Pneumatic otoscopy is sometimes utilized to evaluate the mobility of the tympanic membrane. Few pediatricians have the facility to do otomicroscopy, because of the large financial expense and the amount of time required for microscopic examination of the eardrum. Occasionally, an equivocal otoscopic examination along with a normal screening audiogram give the false impression that no middle ear disease exists. At times, the otoscopic examination may be unsatisfactory because of a restless patient, narrow ear canals,