An expanded version of the Hammersmith Functional Motor Scale for SMA II and III patients.
OBJECTIVE
To develop and evaluate an expanded version of the Hammersmith Functional Motor Scale allowing for evaluation of ambulatory SMA patients.


METHODS
Thirty-eight patients with SMA type II or III were evaluated using the Gross Motor Function Measure and the Hammersmith Functional Motor Scale. Based on statistical and clinical criteria, we selected 13 Gross Motor Function Measure items to develop an expanded HFMS. The expanded Hammersmith Functional Motor Scale was validated by comparison with the Gross Motor Function Measure minus the 13 items (GMFM-75) and an assessment of clinical function. The reliability of the expanded Hammersmith Functional Motor Scale in 36 patients was established.


RESULTS
The expanded Hammersmith Functional Motor Scale was highly correlated with the GMFM-75 and the clinical function assessment (p=0.97, and p=0.90). The expanded Hammersmith Functional Motor Scale showed excellent test-retest reliability (International Coordinating Committee = 0.99).


CONCLUSIONS
The expanded Hammersmith Functional Motor Scale allows assessment of high functioning SMA type II and III patients. Ease of administration and correlation with established motor function measures justify use in future SMA clinical trials.
Columbia University, New York, NY, USA. johagan@neuro.columbia.edu
Jessica M
JM
O'Hagen
Allan M
AM
Glanzman
Michael P
MP
McDermott
Patricia A
PA
Ryan
Jean
J
Flickinger
Janet
J
Quigley
Susan
S
Riley
Erica
E
Sanborn
Carrie
C
Irvine
William B
WB
Martens
Christine
C
Annis
Rabi
R
Tawil
Maryam
M
Oskoui
Basil T
BT
Darras
Richard S
RS
Finkel
Darryl C
DC
De Vivo
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014897:Spinal Muscular Atrophies of Childhood / Q000175:diagnosis* / Q000503:physiopathology*