Background Due to sympathetic de-centralization, individuals with spinal cord injury (SCI), especially those with tetraplegia, often present with hypotension, worsened with upright posture. Several investigations in the non-SCI population have noted a relationship between chronic hypotension and deficits in memory, attention and processing speed and delayed reaction times. Objective To determine cognitive function in persons with SCI who were normotensive or hypotensive over a 24-h observation period while maintaining their routine activities. Methods Subjects included 20 individuals with chronic SCI (2–39 years), 13 with tetraplegia (C4–8) and 7 with paraplegia (T2–11). Individuals with hypotension were defined as having a mean 24-h systolic blood pressure (SBP) below 110 mmHg for males and 100 mmHg for females, and having spent ≥50% of the total time below these gender-specific thresholds. The cognitive battery used included assessment of memory (CVLT), attention and processing speed (Digit Span, Stroop word and color and Oral Trails A), language (COWAT) and executive function (Oral Trails B and Stroop color–word). Results Demographic parameters did not differ among the hypotensive and normotensive groups; the proportion of individuals with tetraplegia (82%) was higher in the hypotensive group. Memory was significantly impaired (P<0.05) and there was a trend toward slowed attention and processing speed (P<0.06) in the hypotensive compared to the normotensive group. Interpretation These preliminary data suggest that chronic hypotension in persons with SCI is associated with deficits in memory and possibly attention and processing speed, as previously reported in the non-SCI population.

Background/Aims: The high risk and prevalence of dementia among patients with chronic kidney disease (CKD) and in those receiving hemodialysis (HD) may be preceded by mild cognitive impairment (MCI). We aimed to assess cognitive function in CKD and HD patients with no history of stroke or dementia, in order to identify and characterize early cognitive deficits. Methods: 24 CKD and 27 HD male outpatients without history of cerebrovascular or neurodegenerative disease underwent comprehensive neuropsychological testing in an observational cross-sectional study. Test results were used to categorize patients into MCI subtypes. Results: All subjects scored ≧28 on the Mini-Mental State Examination. The prevalence of executive function was at least 25% in both groups and memory impairment occurred in 13% of the HD patients and 15% of those with CKD. MCI occurred in 76% of the group and HD patients showed a higher prevalence of MCI compared to CKD patients (89 vs. 63%) with a preponderance (>70%) of cases across both groups classified as non-amnestic MCI. Conclusion: Predialysis CKD and HD patients have a high prevalence of MCI despite normal global cognitive function. MCI was more prevalent among the HD patients and deficits more frequently resulted in non-amnestic MCI.

Background/Aims: Cognitive impairment (CI) is highly prevalent among hemodialysis (HD) patients and is associated with increased morbidity and mortality. The aim was to compare cognitive function in HD patients with no history of stroke or dementia and well-matched controls. Studies are required to determine the impact of HD and chronic kidney disease-specific risks on CI. Methods: 76 outpatients (50 receiving outpatient HD and 26 with normal kidney function matched for age and comorbidity) underwent a cross-sectional observational study. HD patients were well dialyzed and had optimal hemoglobin levels. A battery of eight neuropsychological tests was used. Outcomes included assessment scores of neurocognitive testing and prevalence and subtype of CI. Results: Compared to controls, HD subjects had significantly lower composite scores for each tested cognitive domain. In each domain except memory, the percentage of subjects with impairment was significantly higher in HD subjects than controls. Differences between the groups were independent of vascular and dementia risk factors. 82% of HD subjects met criteria for CI versus 50% of controls. Non-amnestic subtype of CI was more prevalent in both groups. Conclusion: Well-dialyzed HD patients with optimized hemoglobin levels and with no history of stroke or dementia performed significantly worse on multiple measures of cognition compared to controls. A higher prevalence of non-memory impairment may suggest an underlying vascular versus neurodegenerative mechanism. HD and chronic kidney disease-specific risk factors may contribute to early CI not readily detected by routine screening methods.

Asymptomatic hypotension relates to cognitive performance in persons with tetraplegia; therefore, BP normalization should be considered. The inappropriate cerebral vascular response to cognitive testing and poor test performance should be investigated in persons with paraplegia.