TABLE 6.

Association between clinical outcomes —muscle strength, Amyotrophic Lateral Sclerosis (ALS) Functional Rating Scale revised total score and upper limb subscore—and gray matter area at corresponding inter‐vertebral disc levels in patients with ALS, covarying for age and sex.

Model	Outcome	Factor	Standardized estimate	SE	t value	p
Model 1: adj. r 2 = 37.1%; p = 0.0006	Muscle strength (N); Deltoid	Intercept	0.004	0.14	0.03	0.9769
		GM area at C3/C4	0.63	0.14	4.37	0.0001
		Age	−0.06	0.15	−0.42	0.6778
		Sex	0.09	0.14	0.63	0.5310
Model 2: adj. r 2 = 16.3%; p = 0.0396	Muscle strength (N); Brachioradialis	Intercept	0.024	0.16	0.15	0.8801
		GM area at C4/C5	0.41	0.16	2.49	0.0186
		Age	−0.24	0.16	−1.47	0.1509
		Sex	0.06	0.17	0.35	0.7260
Model 3: adj. r 2 = 30.8%; p = 0.0027	Muscle strength (kg); Hand Grip	Intercept	−0.003	0.15	−0.02	0.9840
		GM area at C5/C6	0.51	0.15	3.38	0.0020
		Age	−0.19	0.15	−1.26	0.2174
		Sex	0.21	0.16	1.37	0.1794
Model 4: adj. r 2 = 26.2%; p = 0.0068	Muscle strength (N); First dorsal interosseus	Intercept	0.003	0.15	0.02	0.9865
		GM area at C5/C6	0.56	0.16	3.58	0.0012
		Age	−0.06	0.16	−0.39	0.6958
		Sex	0.15	0.16	0.94	0.3572
Model 5: adj. r 2 = 18.4%; p = 0.0279	Muscle strength (N); Tibialis anterior	Intercept	0.020	0.16	0.12	0.9034
		GM area at T max	0.47	0.17	2.81	0.0087
		Age	−0.07	0.18	−0.39	0.6959
		Sex	0.14	0.17	0.83	0.4142
Model 6: adj. r 2 = 32.5%; p = 0.0016	SNIP (cmH2O)	Intercept	−0.005	0.14	−0.03	0.9724
		GM area at C3/C4	0.36	0.15	2.45	0.0200
		Age	−0.35	0.15	−2.29	0.0287
		Sex	0.16	0.15	1.07	0.2911
Model 7: adj. r 2 = 40.5%; p = 0.0002	ALSFRS‐R total score	Intercept	38.210	0.97	39.37	<0.0001
		GM area at C3/C4	4.83	1.01	4.77	<0.0001
		Age	0.39	1.04	0.37	0.7103
		Sex	−1.21	1.01	−1.19	0.2419

p values with a significance level <0.05 are marked in bold.

Abbreviations: ALSFRS‐R, Amyotrophic Lateral Sclerosis Functional Rating Scale–revised; GM, gray matter; kg, kilograms; N, Newton; SE, standard error; SNIP, sniff nasal inspiratory pressure.