Central cholinergic dysfunction measured "in vivo" correlates with different behavioral disorders in Alzheimer's disease and dementia with Lewy body.
BACKGROUND
Cholinergic deficits have been largely correlated to behavioral disorders in dementia. However, cholinergic deficits are not homogeneous and they are distributed differently in the basal forebrain and brainstem among Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). The different cholinergic networks involved suggest different patterns of behavior symptomatology in the two groups.


OBJECTIVE
To correlate the deficit of cholinergic activity, measured in vivo by the short latency afferent inhibition (SAI) technique, with the behavioral symptoms in patients affected by DLB and AD.


METHODS
Behavioral and neuropsychologic tests including Neuropsychiatric Inventory (NPI), mini-mental status examination (MMSE), and an extensive neuropsychologic investigation were administered to 18 DLB patients and 18 one-to-one matched AD patients. SAI data were compared with those from a control group of age-matched healthy individuals and the level of SAI in patients was correlated with behavioral measures.


RESULTS
AD tended to be more impaired than DLB on long-term memory, whereas DLB were more impaired than AD on constructional praxis tasks. NPI total score was similar but with a different behavioural pattern in DLB and AD. In particular, delusions and hallucinations prevailed in DLB patients, whereas affective disturbances prevailed in AD patients. SAI was significantly reduced both in AD and DLB patients when compared with controls; SAI correlated with hallucinations in DLB patients and with euphoric manic state and disinhibition in AD patients.


CONCLUSIONS
Reduction of cholinergic activity as evaluated by SAI measurement correlates with different behavior disorders in AD and DLB patients.
Department of Neuroscience, Centre for Neuropsychological Research, Catholic University of Rome, Rome, Italy. cmarra@rm.unicatt.it
Camillo
C
Marra
Davide
D
Quaranta
Paolo
P
Profice
Fabio
F
Pilato
Fioravante
F
Capone
Francesco
F
Iodice
Vincenzo
V
Di Lazzaro
Guido
G
Gainotti
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D059329:Cholinergic Neurons / Q000502:physiology*; D003702:Delusions / Q000150:complications / Q000503:physiopathology / Q000523:psychology; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006212:Hallucinations / Q000150:complications / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D020961:Lewy Body Disease / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D050781:Transcranial Magnetic Stimulation