Neurodegeneration in Parkinson’s disease dementia (PDD) and dementia with Lew y bodies (DLB) affect cortical and subcortical networks involved in saccade gene ration. We therefore expected impairments in saccade perf...Neurodegeneration in Parkinson’s disease dementia (PDD) and dementia with Lew y bodies (DLB) affect cortical and subcortical networks involved in saccade gene ration. We therefore expected impairments in saccade performance in both disorde rs. In order to improve the pathophysiological understanding and to investigate the usefulness of saccades for differential diagnosis, saccades were tested in a ge-and education-matched patients with PDD (n=20) and DLB (n=20), Alzheimer’s disease (n=22) and Parkinson’s disease (n=24), and controls (n=24). Reflexive (gap, overlap) and complex saccades (prediction, decision and antisaccade) were tested with electrooculography. PDD and DLB patients had similar impairment in a ll tasks (P > 0.05, not signifi cant). Compared with controls, they were impaire d in both reflexive saccade execution (gap and overlap latencies, P < 0.0001; ga ins, P < 0.004) and complex saccade performance (target prediction, P < 0.0001; error decisions, P < 0.003; error antisaccades: P < 0.0001). Patients with Alzhe imer’s disease were only impaired in complex saccade performance (Alzheimer’s disease versus controls, target prediction P < 0.001, error decisions P < 0.0001 , error antisaccades P < 0.0001), but not reflexive saccade execution (for all, P >0.05). Patients with Parkinson’s disease had, compared with controls, similar complex saccade performance (for all, P > 0.05) and only minimal impairment in reflexive tasks, i.e. hypometric gain in the gap task (P=0.04). Impaired saccade execution in re flexive tasks allowed discrimination between DLB versus Alzheimer’s disease (se nsitivity ≥60%, specificity ≥77%)-and between PDD versus Parkinson’s disea se (sensitivity ≥60%, specificity ≥88%) when ±1.5 standard deviations was u sed for group discrimination. We conclude that impairments in reflexive saccades may be helpful for differential diagnosis and are minimal when either cortical (Alzheimer’s disease) or nigrostriatal neurodegeneration (Parkinson’s disease) exists solely; however, they become prominent with combined cortical and subcor tical neurodegeneration in PDD and DLB. The similarities in saccade performance in PDD and DLB underline the overlap between these conditions and underscore dif ferences from Alzheimer’s disease and Parkinson’s disease.展开更多
Age-related physiological impairments of heart rate, blood pressure and cerebral blood flow, in combination with comorbid conditions and concurrent medications, account for an increased susceptibility to syncope in ol...Age-related physiological impairments of heart rate, blood pressure and cerebral blood flow, in combination with comorbid conditions and concurrent medications, account for an increased susceptibility to syncope in older adults. Common causes of syncope are orthostatic hypotension, neurally-mediated syncope (including carotid sinus syndrome) and cardiac arrhythmias. A high proportion of older patients with cardiovascular syncope present with falls and deny loss of consciousness. Patients who are cognitively normal and have unexplained falls should have a detailed cardiovascular assessment.展开更多
文摘Neurodegeneration in Parkinson’s disease dementia (PDD) and dementia with Lew y bodies (DLB) affect cortical and subcortical networks involved in saccade gene ration. We therefore expected impairments in saccade performance in both disorde rs. In order to improve the pathophysiological understanding and to investigate the usefulness of saccades for differential diagnosis, saccades were tested in a ge-and education-matched patients with PDD (n=20) and DLB (n=20), Alzheimer’s disease (n=22) and Parkinson’s disease (n=24), and controls (n=24). Reflexive (gap, overlap) and complex saccades (prediction, decision and antisaccade) were tested with electrooculography. PDD and DLB patients had similar impairment in a ll tasks (P > 0.05, not signifi cant). Compared with controls, they were impaire d in both reflexive saccade execution (gap and overlap latencies, P < 0.0001; ga ins, P < 0.004) and complex saccade performance (target prediction, P < 0.0001; error decisions, P < 0.003; error antisaccades: P < 0.0001). Patients with Alzhe imer’s disease were only impaired in complex saccade performance (Alzheimer’s disease versus controls, target prediction P < 0.001, error decisions P < 0.0001 , error antisaccades P < 0.0001), but not reflexive saccade execution (for all, P >0.05). Patients with Parkinson’s disease had, compared with controls, similar complex saccade performance (for all, P > 0.05) and only minimal impairment in reflexive tasks, i.e. hypometric gain in the gap task (P=0.04). Impaired saccade execution in re flexive tasks allowed discrimination between DLB versus Alzheimer’s disease (se nsitivity ≥60%, specificity ≥77%)-and between PDD versus Parkinson’s disea se (sensitivity ≥60%, specificity ≥88%) when ±1.5 standard deviations was u sed for group discrimination. We conclude that impairments in reflexive saccades may be helpful for differential diagnosis and are minimal when either cortical (Alzheimer’s disease) or nigrostriatal neurodegeneration (Parkinson’s disease) exists solely; however, they become prominent with combined cortical and subcor tical neurodegeneration in PDD and DLB. The similarities in saccade performance in PDD and DLB underline the overlap between these conditions and underscore dif ferences from Alzheimer’s disease and Parkinson’s disease.
文摘Age-related physiological impairments of heart rate, blood pressure and cerebral blood flow, in combination with comorbid conditions and concurrent medications, account for an increased susceptibility to syncope in older adults. Common causes of syncope are orthostatic hypotension, neurally-mediated syncope (including carotid sinus syndrome) and cardiac arrhythmias. A high proportion of older patients with cardiovascular syncope present with falls and deny loss of consciousness. Patients who are cognitively normal and have unexplained falls should have a detailed cardiovascular assessment.
