Neck weakness is a potent prognostic factor in sporadic amyotrophic lateral sclerosis patients.
OBJECTIVE
To clarify the emergence of muscle weakness in regions of the body that affect survival, and deterioration in activities of daily living (ADL) in amyotrophic lateral sclerosis (ALS) patients.


METHODS
We conducted a multicentre-based prospective cohort study of patients with ALS. We enrolled 401 sporadic patients with ALS. Death or the introduction of invasive ventilation was defined as the primary endpoint, and the time to five clinical markers of ADL deterioration associated with bulbar paralysis or limb weakness were defined as ADL milestones. Muscle weakness was assessed in the neck flexor muscles; the bilateral abductors of the shoulders; the bilateral wrist extensor muscles; the bilateral flexor muscles of the hips; and the bilateral ankle dorsiflexion muscles. We performed Cox proportional hazards regression analyses for the primary endpoint and the five ADL milestones, adjusting for known covariate prognostic factors for ALS.


RESULTS
The Medical Research Council (MRC) score for the neck flexors was the most significant prognostic factor for the primary endpoint (HR 0.74, p<0.001), loss of speech (HR 0.66, p<0.001), and loss of swallowing function (HR 0.73, p<0.001), and was one of the significant prognostic factors for loss of upper limb function, difficulty turning in bed, and loss of walking ability (p=0.001, 0.002, and 0.008, respectively). The MRC score for the neck flexors was also a significant prognostic factor for covariates of the previously reported prognostic factors.


CONCLUSIONS
Neck weakness is an independent prognostic factor for survival and deterioration in ADL in Patients with ALS.
Department of Neurology, Nagoya University Graduate School of Medicine, , Nagoya, Japan.
Ryoichi
R
Nakamura
Naoki
N
Atsuta
Hazuki
H
Watanabe
Akihiro
A
Hirakawa
Hirohisa
H
Watanabe
Mizuki
M
Ito
Jo
J
Senda
Masahisa
M
Katsuno
Fumiaki
F
Tanaka
Yuishin
Y
Izumi
Mitsuya
M
Morita
Kotaro
K
Ogaki
Akira
A
Taniguchi
Ikuko
I
Aiba
Koichi
K
Mizoguchi
Koichi
K
Okamoto
Kazuko
K
Hasegawa
Masashi
M
Aoki
Akihiro
A
Kawata
Koji
K
Abe
Masaya
M
Oda
Masaaki
M
Konagaya
Takashi
T
Imai
Masanori
M
Nakagawa
Shoji
S
Tsuji
Ryuji
R
Kaji
Imaharu
I
Nakano
Gen
G
Sobue
D000203:Activities of Daily Living; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D015415:Biomarkers; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000150:complications / Q000503:physiopathology*; D009333:Neck / Q000503:physiopathology*; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors
D015415:Biomarkers
ALS; Clinical Neurology; Neuroepidemiology