Vol 5 n° 1 - Dementia
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Keywords:  Alzheimer’s  disease;  dementia;  cholinesterase  inhibitor;  tacrine; donepezil; rivastigmine; galantamine Author affiliations: University of Manchester, Education and Teaching Centre, Wythenshawe Hospital, Manchester, UK Address  for  correspondence:  Prof  Alistair  Burns,  University  of  Manchester, Education  and  Teaching  Centre,  Wythenshawe  Hospital,  Manchester,  M23 9LT, UK (e-mail: a_burns@man.ac.uk) lzheimer’s disease is the commonest cause of dementia and describes a clinical syndrome made up of three  domains.  First,  a  neuropsychological  domain encompassing those deficits of cognitive function such as amnesia (memory loss), aphasia (language disturbance), apraxia (the inability to carry out motor tasks despite intact motor functions), and agnosia (the inability to rec- ognize people or objects despite intact sensory func- tions). Second, a  group  of  psychiatric  symptoms  and behavioral disturbances, which have been termed neu- ropsychiatric  features,1  noncognitive  phenomena,  or behavioral  and  psychological  symptoms  of  dementia (BPSD).2 These consist of psychiatric symptoms (such as delusions, hallucinations, depression, paranoid ideas, and misidentifications) and behavioral disturbances (such as aggression, wandering, and sexual disinhibitions). Third, problems with activities of daily living (ADL), which include instrumental ADL in the early stages of demen- tia when the person is unable to carry out complex tasks, such as shopping, driving, and using the telephone, and basic ADL in the later stages of dementia, when a person is unable to go to the toilet or feed, dress, and wash them- selves. Causes of dementia The  relative  frequency  of  causes  of  dementia  vary depending on the population under study. Alzheimer’s disease is probably the commonest form (about 50%), followed by vascular dementia (about 25%) and demen- tia with Lewy bodies (about 20%), with the other 5% being made up of reversible dementias and rarer forms P h a r m a c o l o g i c a l   a s p e c t s 3 5 Treatment of cognitive impairment in Alzheimer’s disease Alistair Burns, MD, FRCP, FRCPsych A In Alzheimer’s disease, cognition now responds to several drugs. Anticholinesterases target the acetylcholine deficit. In mild-to-moderate Alzheimer’s disease, they all provide significant  benefit  versus  placebo  on  the  Alzheimer’s Disease Assessment Schedule–Cognitive Section (ADAS- Cog). Side effects, in 5% to 15% of cases, include nausea, vomiting, diarrhea, anorexia, and dizziness. Tacrine, the leading anticholinesterase, caused frequent hepatic enzyme elevation and was withdrawn; once-daily donepezil spares the liver and improves global measures of change in severe dementia; rivastigmine is indicated in comorbid vascular disease; while galantamine modulates the cerebral nico- tinic acetylcholine receptors that potentiate the response to acetylcholine. Alternative agents include the N-methyl- D-aspartate (NMDA) receptor antagonist, memantine, licensed  in  Europe  for  moderately  severe  to  severe Alzheimer’s disease; it acts on a different neurotransmit- ter system present in 70% of neurons, protecting against pathologic glutamergic activation while preserving or even restoring physiologic glutamergic activation. The clinician’s armamentarium in AD has never been greater. Dialogues Clin Neurosci. 2003;5:35-43.