A FMRI Episodic Memory Study A longitudinal protocol
in 31 patients presentingwith early memory complain
F. GelbertC. Belin, A.M. Ergis,
C. Moroni, C. Baclet-Roussel, C. Nioche, J.L. Sarrazin
Paris- France
This fMRI study is part of a multimodal protocol including clinical, biological, neuropsychological and standard MR .
The goal of the study was to evaluate the feasability of a FMRI memory protocol in a routine clinical situation
Normal Aging
MCIMemoryDisorders < 1.5 SD
AD
Early Detection Futur Therapeutic Approaches
Episodic Memory
Longitudinal multimodal study concerning 36 aged patients who complained for
Memory Loss2 FMRI Paradigms
PARADIGM 1Memory paradigm
PARADIGM 2Fluency
Verbal letter fluency is preserved in MCI
Results to the Fluency test =
a baseline standard for each patient
8 blocks of rest and stimulation periods
Each period : 28 seconds.
During the rest periods, subjects were instructed to think of something unrelated t the stimulation.
Total scanning time: 3 minutes 56 seconds.
Temps
Act
ivat
ion
AA
A
A
RR
RR
R
Paradigms
1.5 Tesla MR scanner : (GE Healhtcare Signa ExHD,) using a phased array 8-elements head coil.
Functional images : T2 EPI/GE. TR : 4.0 ms, TE :60 ms, flip angle 90 , FOV 260 mm, matrix size 64x64,
slice thickness 5.0 mm.
Anatomical images : 3D SPGR TR 7.6 ms, TE 1.6 ms, FOV 260 mm, matrix 256x256, NEX 1,
slice thickness 1.4 mm.
Image acquisition
Memory paradigm from the Memory DSM 48 test (Barbeau et al, Neurology 2002)
Before scanning
Visual stimuli were generated using a laptop and a video projector positioned on the scanner bed. The images projected on a white wall were seen by the patients using a mirror adapted to the head coil.
visual memory task2 runs
more or less than 3 colors. ?
silently answer with yes or no.
3 COLORS ? MORE ? LESS ?
3 COLORS ? MORE ? LESS ?
3 COLORS ? MORE ? LESS ?
Subjects were asked to retrieve as many words as possible with a particular letter defined by an instruction slide
P R S T
Verbal Fluency task
Each target is paired with a distractor
on the left or right side of the slide.
Instructions are
given just before scanning
The patient is asked to silently answered
Right or Left for the identified
item
Right or Left ?
Recognition task of the Memory test
Right or Left ?
Right or Left ?
Statistical Parametric Mapping SPM99 and BAR (home software, HIA Val de Grâce. Paris)
individual T-test maps comparing rest and experimental conditions on a voxel-by-voxel basis.
Data were modeled with a fixed response (box-car)
Data analysis andimage processing
36 patients were included in the fMRI protocol (Age ranged : 70-88, mean age : 78)
19 males, 17 females14 patients had a normal cognitive status22 patients presented with MCI
Along the evolution we categorized 3 groups Cognitively normal individual that remain stable: 12 MCIpatients that remain stable :7 MCI patients developing dementia :3
Results
22 patients have completed the MR protocol at the time being.
Results
Strongly lateralised activation in the left hemisphere in the dorsolateral prefontal cortexMore bilateralized pattern than younger patients
Verbal Fluency task Normal subjects
left right
Normal subjectsMemory test
Bilateral activation parietal ,inferior temporal cortexMedial temporal cortexCingulate cortexVisual areas Middle frontal cortex
Fluency testMCI patients
Bilateralized pattern
MCI Memory test
MCI –AD Convertors Fluency test
Initial exam
MCI- AD convertorsMemory test
Initial exam
Conclusion
We did not faced technical limitations related to the age of the patients.No problem to read the letters and analyse the imagesThe entire procedure was performed within a 30 min
examination timeConsidering the results, the verbal fluency test was
reproductively performed even in the early MCI stage.The memory test suffered for the short numbert of
patients at the time being. This experience confirmed the feasability of a Fmri study
in a routine clinical practice at least in the first stage of memory loss
Special Thanks to the Fondation Philippe Chatrier
•Sabine Tranchant, Aurélie Sager•Mrs Gelbert aged 85 who kindly helped us to adapt the different visual parameters to this specific clinical condition
And before memory fade away ……………..
