Evaluation of visual recognition memory in MCI patients.
BACKGROUND
Neurofibrillary tangles seen early in Alzheimer disease (AD) initially appear in a subregion of the perirhinal cortex. In the monkey, damage to the perirhinal cortex impairs performance on visual recognition memory tasks. The authors evaluated impairment of visual recognition memory as a potential early diagnostic marker of AD.


METHODS
The authors developed a visual delayed matching-to-sample task (DMS48) designed to assess visual recognition memory in humans. Twenty-three patients fulfilling the criteria of amnestic mild cognitive impairment (MCI) (mean Mini-Mental State Examination [MMSE]: 26.6, SD = 1.6) were recruited. All underwent a full neuropsychological evaluation, which included the Free and Cued Selective Reminding (FCSR) test. Their performance was compared with that of 10 patients with mild AD, 20 patients with moderate AD, 20 patients with Parkinson disease (PD), and 40 age-matched controls.


RESULTS
Control subjects and patients with PD performed close to ceiling. Patients with mild AD had very low scores, while patients with moderate AD answered at random. MCI patients obtained scores that were between those of control subjects and patients with mild AD (78%, SD = 16%). MCI patients who failed on the DMS48 had lower scores on free recall (p < 0.05) and received less benefit from cueing (p < 0.01) on the FCSR than the other MCI, suggesting a profile of genuine memory impairment related to medial temporal lobe lesions.


CONCLUSIONS
The DMS48, a test of visual recognition memory, is impaired early in the course of patients with MCI. Further studies are necessary to determine whether the evaluation of visual recognition memory may contribute to the identification of patients with AD.
Barbeau
E
E
Laboratoire de Neurophysiologie et Neuropsychologie, Inserm EMI-U 9926, Faculté de Médecine, Univ. Mediterranee, Marseille, France. emmanuel.barbeau@medecine.univ-mrs.fr
Didic
M
M
Tramoni
E
E
Felician
O
O
Joubert
S
S
Sontheimer
A
A
Ceccaldi
M
M
Poncet
M
M
D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology*; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis*; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D013702:Temporal Lobe / Q000503:physiopathology