Objective: There are few detailed data on cognition in patients undergoing dialysis. We evaluated the frequency of and risk factors for poor cognitive performance using detailed neurocognitive testing.Methods: In this cross-sectional cohort study, 314 hemodialysis patients from 6 Boston-area hemodialysis units underwent detailed cognitive assessment. The neuropsychological battery assessed a broad range of functions, with established age-, sex-, and education-matched normative scores. Principal component analysis was used to derive composite scores for memory and executive function domains. Risk factors for each domain were evaluated using linear regression adjusting for age, sex, race, and education status. Analyses were repeated in those with Mini-Mental State Examination (MMSE) score $24.Results: Compared with population norms, patients on dialysis had significantly poorer executive function but not memory performance, a finding that persisted in the subgroup with MMSE score $24. In adjusted analyses, vascular risk factors and vascular disease were associated with lower executive function (p , 0.01).Conclusions: There is a high frequency of poor cognitive performance in hemodialysis patients, primar- Cognitive impairment in dialysis is an increasingly important public health problem given the aging end-stage renal disease (ESRD) population and the increasing prevalence of diabetes and vascular disease. In older studies in hemodialysis patients, cognitive impairment, defined by poor performance on the Mini-Mental State Examination (MMSE), was present in 40% to 60%. 1-3 Despite the fact that the MMSE remains the most frequently used screening tool for cognitive impairment, it focuses on memory and largely neglects other cognitive domains such as executive function; accordingly, the MMSE may not be sufficient to detect more subtle degrees of cognitive impairment.The major causes of dementia in the general population are Alzheimer disease, which initially manifests with memory loss with later involvement of other cognitive domains, and vascular dementia, which primarily manifests with impairment in executive function. [4][5][6][7] Although it is likely that patients undergoing dialysis have similar causes for cognitive impairment as the general population, there are few studies that have attempted to distinguish the prevalence of and risk factors for each type of cognitive impairment in this population.The goals of this study were therefore to evaluate the frequency of and risk factors for poor cognitive performance in hemodialysis patients using detailed measures of multiple cognitive domains, From the Division of Nephrology (M.J.S., K

Background Although dialysis patients are at high risk for stroke and have a high burden of cognitive impairment, there are few reports on anatomic brain findings in the hemodialysis population. Using brain magnetic resonance imaging (MRI), we compared the prevalence of brain abnormalities in hemodialysis patients to a control population without known kidney disease. Study Design Cross-sectional cohort. Setting & Participants 45 maintenance hemodialysis patients and 67 controls without reported kidney disease, both without prior history of known stroke. Predictor The primary predictor was dialysis status. Covariates included demographics (age, race, sex), vascular risk factors (diabetes and hypertension) and cardiovascular disease (coronary artery disease, congestive heart failure). Outcomes Brain MRI features including severity of white matter disease and cerebral atrophy (sulcal prominence and ventricular atrophy), hippocampal size, and small/large vessel infarcts. Measurements Semi-quantitative scale (0-9 for white matter disease and cerebral atrophy, 0-3 for hippocampal size) and infarct prevalence. Results The mean age of hemodialysis patients and controls was 55 ± 17 (SD) and 53 ± 13 years, respectively. In comparison with controls, hemodialysis patients had more severe white matter disease (1.6 v 0.7) and cerebral atrophy (sulcal prominence = 2.3 v 0.6; ventricular enlargement = 2.3 v 0.9; hippocampal size = 1.3 v 1.0) with all p-values <0.001. In multivariable analyses, hemodialysis status was independently associated with worse white matter disease and atrophy grades. Hemodialysis patients also had a higher prevalence of small (17.8%) and large (7.8%) vessel infarcts than controls (combined 22% vs 0%, p<0.001). Limitations The dialysis cohort is likely healthier than the overall US hemodialysis population, partly limiting generalizability. Conclusions Hemodialysis patients have more white matter disease and cerebral atrophy compared to controls without known kidney disease. Hemodialysis patients also have a high prevalence of unrecognized infarcts.

Background Cognitive impairment is common in hemodialysis patients and associated with significant morbidity. Limited information exists on whether cognitive impairment is associated with survival, and whether type of cognitive impairment is important. Study Design Longitudinal cohort. Setting & Participants Cognitive function was assessed at baseline and yearly using a comprehensive battery of cognitive tests in 292 prevalent hemodialysis patients. Predictor Using principal component analysis, individual test results were reduced into 2 domain scores, representing memory and executive function. By definition, each score carried a mean of 0 and SD of 1. Outcomes Association of each score with all-cause mortality was assessed using Cox proportional hazards models adjusted for demographics as well as dialysis and cardiovascular (CV) risk factors. Results Mean age of participants was 63 years, 53% were male, 23% were African American and 90% had at least a high school education. During median follow up of 2.1 (IQR, 1.1–3.7) years, 145 deaths occurred. Each 1-SD better executive function score was associated with 35% lower hazard of mortality (HR, 0.65; 95% CI, 0.55–0.76). In models adjusting for demographics and dialysis-related factors, this relationship was partially attenuated but remained significant (HR, 0.81; 95% CI, 0.67–0.98), while adjustment for CV disease and heart failure further attenuated it (HR, 0.87; 95% CI, 0.72–1.06). Use of time-dependent models showed a similar unadjusted association (HR, 0.62; 95% CI, 0.54–0.72), with the relationship remaining significant after adjustment for demographics, dialysis, and CV risk factors (HR, 0.79; 95% CI, 0.66–0.94). Better memory was associated with lower mortality in univariate analysis (HR per 1 SD, 0.82 [95% CI, 0.69–0.96]), but not when adjusting for demographics (HR, 1.00; 95% CI, 0.83–1.19). Limitations Patients with dementia were excluded from the full battery, perhaps underestimating strength of the association. Conclusions Worse executive function and memory are associated with increased risk of mortality. For memory, this association is explained by patient demographics, while for executive function this relationship may be partly explained by CV disease burden.

Superior canal dehiscence (SCD) is caused by an absence of bony covering of the arcuate eminence or posteromedial aspect of the superior semicircular canal. However, the clinical presentation of SCD syndrome varies considerably, as some SCD patients are asymptomatic and others have auditory and/or vestibular complaints. In order to determine the basis for these observations, we examined the association between SCD length and location with: (1) auditory and vestibular signs and symptoms; (2) air conduction (AC) loss and air-bone gap (ABG) measured by pure-tone audiometric testing, and (3) cervical vestibular-evoked myogenic potential (cVEMP) thresholds. 104 patients (147 ears) underwent SCD length and location measurements using a novel method of measuring bone density along 0.2-mm radial CT sections. We found that patients with auditory symptoms have a larger dehiscence (median length: 4.5 vs. 2.7 mm) with a beginning closer to the ampulla (median location: 4.8 vs. 6.4 mm from ampulla) than patients with no auditory symptoms (only vestibular symptoms). An increase in AC threshold was found as the SCD length increased at 250 Hz (95% CI: 1.7-4.7), 500 Hz (95% CI: 0.7-3.5) and 1,000 Hz (95% CI: 0.0-2.5), and an increase in ABG as the SCD length increased at 250 Hz (95% CI: 2.0-5.3), 500 Hz (95% CI: 1.6-4.6) and 1,000 Hz (95% CI: 1.3-3.3) was also seen. Finally, a larger dehiscence was associated with lowered cVEMP thresholds at 250 Hz (95% CI: -4.4 to -0.3), 500 Hz (95% CI: -4.1 to -1.0), 750 Hz (95% CI: -4.2 to -0.7) and 1,000 Hz (95% CI: -3.6 to -0.5) and a starting location closer to the ampulla at 250 Hz (95% CI: 1.3-5.1), 750 Hz (95% CI: 0.2-3.3) and 1,000 Hz (95% CI: 0.6-3.5). These findings may help to explain the variation of signs and symptoms seen in patients with SCD syndrome.

Background: There are limited data regarding the relationship between depression and mortality in hemodialysis (HD) patients. Methods: Among 323 patients receiving maintenance HD, depression symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale, with a score of ≥16 consistent with depression. Adjusted Cox proportional-hazards models with additional analyses incorporating antidepressant medication use were used to evaluate the association between depression and mortality. Baseline CES-D scores were used for the primary analyses, while secondary time-dependent analyses incorporated subsequent CES-D results. Results: The mean age was 62.9 ± 16.5 years, 46% of the subjects were women and 22% were African-American. The mean baseline CES-D score was 10.7± 8.3, and 83 (26%) participants had CES-D scores ≥16. During a median (25th, 75th) follow-up of 25 (13, 43) months, 154 participants died. After adjusting for age, sex, race, primary cause of kidney failure, dialysis vintage and access, baseline depression was associated with an increased risk of all-cause mortality (HR 1.51 and 95% CI 1.06-2.17). This attenuated with further adjustment for cardiovascular disease, smoking, Kt/V, serum albumin, log C-reactive protein and use of antidepressants (HR 1.21 and 95% CI 0.82-1.80). When evaluating time-dependent CES-D, depression remained associated with increased mortality risk in the fully adjusted model (HR 1.44 and 95% CI 1.00-2.06). Conclusions: Greater symptoms of depression are associated with an increased risk of mortality in HD patients, particularly when accounting for the most proximate assessment. This relationship was attenuated with adjustment for comorbid conditions, suggesting a complex relationship between clinical characteristics and depression symptoms. Future studies should evaluate whether treatment for depression impacts mortality among HD patients.