Two-year study of cervical cord volume and myelin water in primary progressive multiple sclerosis.
BACKGROUND
Spinal cord involvement in multiple sclerosis (MS) is common and an important element in disability. Previous studies demonstrated smaller cervical cord area at the C2 level in MS compared to controls, and a decrease in cord area over 12 months, most marked in primary progressive MS (PPMS). A subset of subjects participating in a multicentre, double-blind, placebo-controlled clinical trial evaluating the efficacy of glatiramer acetate in PPMS (PROMiSe trial) were followed for 2 years.


METHODS
24 PPMS subjects, randomized to placebo (n = 9) and glatiramer acetate (n = 15), and 24 matched controls were studied. Cervical cord volume (CCV) at C2-3 was determined using a 3D inversion recovery (IR)-prepared spoiled-gradient echo sequence. Myelin water fraction (MWF) at C2-3 was obtained using a 32-echo IR-prepared relaxation sequence. Scans were repeated at baseline, years 1 and 2.


RESULTS
Baseline CCV was significantly smaller for PPMS than controls [median (interquartile range) 951 (829-1043) vs. 1072 (1040-1129) mm(3), p = 0.0004] and MWF trended to be lower in PPMS cord [median (interquartile range) 0.225 (0.187-0.267) vs. 0.253 (0.235-0.266), p = 0.12]. Baseline CCV correlated with baseline Expanded Disability Status Scale, disease duration, brain white and grey matter volume. In PPMS, CCV was significantly decreased at year 1 (-0.83%, p = 0.04) and year 2 (-1.65%, p = 0.02). Baseline MWF correlated with baseline CCV and brain white and grey matter volume. MWF was significantly decreased from baseline for PPMS at year 2 (-10.5%, p = 0.01). Treatment effect was not detected on change in CCV nor MWF.


CONCLUSIONS
Metrics at the level of the cord, including volume and MWF at C2-3, were lower in PPMS than controls and changed over 2 years only in PPMS.
Laule
C
C
Radiology, University of British Columbia, Vancouver, BC, Canada. claule@physics.ubc.ca
Vavasour
I M
IM
Zhao
Y
Y
Traboulsee
A L
AL
Oger
J
J
Vavasour
J D
JD
Mackay
A L
AL
Li
D K B
DK
D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D001834:Body Water; D001921:Brain / Q000473:pathology; D002574:Cervical Vertebrae; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D000068717:Glatiramer Acetate; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000188:drug therapy / Q000473:pathology*; D009186:Myelin Sheath / Q000737:chemistry* / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D010455:Peptides / Q000627:therapeutic use; D015203:Reproducibility of Results; D013116:Spinal Cord / Q000187:drug effects / Q000473:pathology*; D016896:Treatment Outcome
D007166:Immunosuppressive Agents; D010455:Peptides; D000068717:Glatiramer Acetate