Table 1.
Overall demographics and most commonly identified co-morbid conditions of individuals with stiff person syndrome spectrum disorders
| Overall (n = 227) | Classic SPS (n = 154) | SPS Plus (n = 48) | PERM (n = 16) | Partial SPS (n = 9) | p-value* | |
|---|---|---|---|---|---|---|
| Age at onset, y, mean (SD) | 42.9 (14.1) | 42.9 (13.6) | 45.2 (13.8) | 35.4(16.9) | 44.8 (18.0) | 0.11 |
| Female, n (%) | 172 (75.8) | 117 (76.0) | 36 (75.0) | 14 (87.5) | 5 (55.6) | 0.36 |
| Race, n (%) | 0.21 | |||||
| White | 157 (69.2) | 118 (76.6) | 25 (52.1) | 9 (56.2) | 5 (55.6) | |
| Black | 50 (22.0) | 25 (16.2) | 19 (39.6) | 5 (31.2) | 1 (11.1) | |
| Asian | 5 (2.1) | 4 (2.6) | 1 (2.1) | 0 | 0 | |
| Other | 15 (6.6) | 7 (4.5) | 3 (6.2) | 2 (12.5) | 3 (33.3) | |
| Hispanic ethnicity, n (%) | 9 (4.0) | 7 (4.5) | 0 | 2 (12.5) | 0 | 0.14 |
| Misdiagnosis, n (%) | 139 (61.2) | 92 (59.7) | 32 (66.7) | 11 (68.8) | 4 (44.4) | 0.53 |
| Time to diagnosis, months, median (IQR) | 36.2 (12.0–79.5) | 33.1 (11.3–72.0) | 52.0 (11.0–97.5) | 53.3 (18.1–81.0) | 36.8 (28.0–63.0) | 0.07 |
| Time to diagnosis, months, mean (SD) | 56.7 (62.9) | 54.1 (64.8) | 69.3 (69.3) | 51.0 (36.5) | 45.4 (21.6) | 0.10 |
| Duration of follow-up, y, mean (SD) | 10.0 (7.5) | 9.9 (7.7) | 11.3 (8.0) | 9.0 (4.6) | 7.2 (3.9) | 0.39 |
| Most common co-morbid medical conditions | ||||||
| Diabetes, n (%) | 72 (31.7) | 49 (31.8) | 15 (31.2) | 3 (18.8) | 5 (55.6) | 0.50 |
| Thyroid disease, n (%) | 83 (36.6) | 58 (37.7) | 16 (33.3) | 7 (43.8) | 2 (22.2) | 1.00 |
| Vitamin B12 deficiency, n (%) | 37 (16.3) | 30 (19.5) | 7 (14.6) | 0 | 0 | 0.27 |
| Vitiligo, n (%) | 13 (5.7) | 8 (5.2) | 3 (6.2) | 1 (6.2) | 1 (11.1) | 0.81 |
| SLE, n (%) | 8 (3.5) | 5 (3.2) | 2 (4.2) | 0 | 1 (11.1) | 0.70 |
| Sjogren’s, n (%) | 10 (4.4) | 7 (4.5) | 2 (4.2) | 0 | 1 (11.1) | 0.74 |
| Anxiety, n (%) | 102 (44.9) | 72 (46.8) | 17 (35.4) | 7 (43.8) | 6 (66.7) | 0.65 |
| Depression, n (%) | 70 (30.8) | 52 (33.8) | 12 (25.0) | 3 (18.8) | 3 (33.3) | 0.72 |
| Paraneoplastic syndrome, n (%) | 9 (3.9) | 5 (55.6) | 2 (22.2) | 0 (0.0) | 1(11.1) | 0.42 |
SPS = stiff person syndrome, PERM progressive encephalomyelitis with rigidity and myoclonus, SLE systemic lupus erythematosus, SD standard deviation, IQR interquartile range, y year(s), n sample size
*p-values reported are overall difference across all phenotypes