Table 2 Data on clinical test and questionnaires.

From: Muscle fat replacement and contractility in patients with skeletal muscle sodium channel disorders

Test

V1293I

(N = 7)

T704M

(N = 7)

T1313M

(N = 13)

V1589M

(N = 2)

G1306E

(N = 2)

All

(N = 31)

Controls

(N = 31)

Phenotype

Paramyotonia congenita

Periodic paralysis

Paramyotonia congenita

Paramyotonia congenita

Sodium channel myotonia

  

Eyelid relaxation time, s (SD)

1.4 (0.76)

0.7 (0.14)

12.3 (11.10)

9.4 (3.1)

61.5 (20.8)

10.2 (16.8)

0.8 (0.15)

Hand relaxation time, s (SD)

1.2 (0.37)

0.7 (0.13)

46.8 (25.5)

10.3 (8.4)

4.8 (1.6)

21.0 (27)

0.7 (0.15)

Jaw relaxation time, s (SD)

1.9 (1.63)

0.7 (0.10)

4.8 (4.7)

4.7 (9.8)

31.2 (5.4)

4.8 (8.0)

0.8 (0.17)

TUG outside reference

0/7

0/7

0/13

1/2

0/2

1/31

0/31

SRT outside reference

2/7

2/7

6/13

2/2

1/2

13/31

0/31

MBS average (0–5)

1.3

2.4

4.0

2

2.5

3.0

–

INQol average

13

8

28

13.5

17.2

18

–

  1. Relaxation times are mean. SD: Standard derivation. TUG: Timed Up and Go. SRT: Sitting and Rising Test. MBS: Myotonia Behavior Scale (score 0–5, as 5 represent debilitating impact of myotonia on daily life). INQoL: Individualized Neuromuscular Quality of Life (score 0–100, as 100 represent very low quality of life). Note that results from the two small genotype groups (p.V1589M n = 2, p.G1306E n = 2) represent very small sample sizes. Both objectively and subjectively, patient heterozygous for p.T1313M suffer from significant myotonia. This patient group also scores worse on quality of life (28).
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