Pupil reaction to light in Alzheimer's disease: evaluation of pupil size changes and mobility.
OBJECTIVE
The aim of the study is to assess pupil size changes and mobility evaluation as a diagnostic marker in patients with probable Alzheimer's disease (AD).


METHODS
Twenty-three control subjects and 23 patients with probable AD entered the study. The latter patients had been under observation for 2 years and had undergone all necessary examinations to verify their initial diagnosis. A full record of the pupil's reaction to light was registered. Ten parameters from these data were measured, reported and then compared in both group of subjects.


RESULTS
Patients with probable AD had abnormal pupillary function compared with such function in healthy aging. All pupillary light reflex (PLR) variables differed significantly between the two groups (p<0.005) except baseline pupil diameter (D1) and minimum pupil diameter (D2). Maximum constriction acceleration (ACmax) was the best predictor in classifying a subject as normal or as AD with perfect classification ability (area under the curve =1, p<0.001). In addition, the correlation between the percentage recovery-redilatation (%D1) and ACmax was highly negative in the group of AD patients (r = -0.808, p<0.005).


CONCLUSIONS
Pupil size changes and mobility examination may be a fast, non-invasive and efficient additional diagnostic marker in AD diagnosis.
Fotiou
Dimitris F
DF
Laboratory of Clinical Neurophysiology, AHEPA Hospital, 54636 Thessaloniki, Greece. ffot@auth.gr
Brozou
Catherine G
CG
Haidich
Anna-Bettina
AB
Tsiptsios
Dimitris
D
Nakou
Maria
M
Kabitsi
Anastasia
A
Giantselidis
Charalambos
C
Fotiou
Fotis
F
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D011680:Pupil / Q000502:physiology*; D012025:Reflex, Pupillary / Q000502:physiology*