White matter hyperintensities alter functional organization of the motor system.
Severe white matter hyperintensities (WMH) represent cerebral small vessel disease and predict functional decline in the elderly. We used fMRI to test if severe WMH impact on functional brain network organization even before clinical dysfunction. Thirty healthy right-handed/footed subjects (mean age, 67.8 ± 7.5 years) underwent clinical testing, structural MRI and fMRI at 3.0T involving repetitive right ankle and finger movements. Data were compared between individuals with absent or punctuate (n = 17) and early confluent or confluent (n = 13) WMH. Both groups did not differ in mobility or cognition data. On fMRI, subjects with severe WMH demonstrated excess activation in the pre-supplementary motor area (SMA), frontal, and occipital regions. Activation differences were noted with ankle movements only. Pre-SMA activation correlated with frontal WMH load for ankle but not finger movements. With simple ankle movements and no behavioral deficits, elderly subjects with severe WMH demonstrated pre-SMA activation, usually noted with complex tasks, as a function of frontal WMH load. This suggests compensatory activation related to disturbance of frontosubcortical circuits.
Linortner
Patricia
P
Department of Neurology, Medical University of Graz, Graz, Austria.
Fazekas
Franz
F
Schmidt
Reinhold
R
Ropele
Stefan
S
Pendl
Barbara
B
Petrovic
Katja
K
Loitfelder
Marisa
M
Neuper
Christa
C
Enzinger
Christian
C
D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle / Q000503:physiopathology; D059345:Cerebral Small Vessel Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D005385:Fingers / Q000503:physiopathology; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology* / Q000503:physiopathology; D009068:Movement; D009778:Occipital Lobe / Q000473:pathology / Q000503:physiopathology