Autonomic dysfunction in dementia
- 1Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Newcastle upon Tyne, UK
- 2Wolfson Centre for Age Related Disorders, King’s College London, Guy’s Campus, St Thomas Street, London, UK
- 3Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne, UK
- 4Regional Medical Physics Department, Royal Victoria Infirmary, Newcastle upon Tyne, UK
- Correspondence to: Dr Louise M Allan Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE, UK;
- Received 18 July 2006
- Accepted 3 December 2006
- Revised 12 November 2006
- Published Online First 18 December 2006
Background: There are no studies of autonomic function comparing Alzheimer’s disease (AD), vascular dementia (VAD), dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD).
Aims: To assess cardiovascular autonomic function in 39 patients with AD, 30 with VAD, 30 with DLB, 40 with PDD and 38 elderly controls by Ewing’s battery of autonomic function tests and power spectral analysis of heart rate variability. To determine the prevalence of orthostatic hypotension and autonomic neuropathies by Ewing’s classification.
Results: There were significant differences in severity of cardiovascular autonomic dysfunction between the four types of dementia. PDD and DLB had considerable dysfunction. VAD showed limited evidence of autonomic dysfunction and in AD, apart from orthostatic hypotension, autonomic functions were relatively unimpaired. PDD showed consistent impairment of both parasympathetic and sympathetic function tests in comparison with controls (all p<0.001) and AD (all p<0.03). DLB showed impairment of parasympathetic function (all p<0.05) and one of the sympathetic tests in comparison with controls (orthostasis; p = 0.02). PDD had significantly more impairment than DLB in some autonomic parameters (Valsalva ratio: p = 0.024; response to isometric exercise: p = 0.002). Patients with VAD showed impairment in two parasympathetic tests (orthostasis: p = 0.02; Valsalva ratio: p = 0.08) and one sympathetic test (orthostasis: p = 0.04). These results were in contrast with AD patients who only showed impairment in one sympathetic response (orthostasis: p = 0.004). The prevalence of orthostatic hypotension and autonomic neuropathies was higher in all dementias than in controls (all p<0.05).
Conclusion: Autonomic dysfunction occurs in all common dementias but is especially prominent in PDD with important treatment implications.
- AD, Alzheimer’s disease
- CAMCOG, Cambridge Examination for Mental Disorders in the Elderly
- DLB, dementia with Lewy bodies
- PD, Parkinson’s disease
- PDD, Parkinson’s disease dementia
- UPDRS, Unified Parkinson’s Disease Rating Scale
- VAD, vascular dementia
Published Online First 18 December 2006
L M Allan was supported by a Research Fellowship from the Alzheimer’s Society. Additional funding was provided by the Medical Research Council.
Competing interests: None.