Mean age at onset, mean time delay from onset to diagnosis and frequency of frontotemporal dementia
| Phenotype | No of cases (%) | Age at onset (years) (mean (SD)) | Age at onset (years) (median (IQR))‡ | Diagnostic delay (months) (mean (SD)) | Diagnostic delay (months) (median (IQR))‡ | Cases with FTD (%) |
| Classic | 404 (30.3) | 62.8 (11.3) | 64.6 (56.1–70.6) | 10.9 (9.6) | 8 (5–13) | 16 (4.0) |
| Bulbar | 456 (34.2) | 68.8 (9.7) | 69.9 (62.9–75.0) | 9.8 (7.0) | 8 (5–12) | 41 (9.0) |
| Flail arm | 74 (5.5) | 62.6 (11.8) | 63.3 (54.8–72.2) | 12.8 (11.0) | 9 (5–15) | 1 (1.4) |
| Flail leg | 173 (13.0) | 65.0 (9.6) | 65.6 (58.5–71.2) | 13.1 (10.1) | 11 (7–17) | 7 (4.1) |
| Pyramidal | 120 (9.1) | 58.3 (13.5) | 60.1 (49.2–68.3) | 15.9 (13.4) | 12 (6–22) | 3 (2.5) |
| Respiratory | 14 (1.1) | 62.2 (8.6) | 62.0 (58.3–65.3) | 6.4 (4.3) | 5 (3–9) | – |
| PLMN | 38 (2.9) | 56.2 (11.3) | 55.2 (45.7–61.3) | 15.5 (12.4) | 14 (10–19) | – |
| PUMN | 53 (4.0) | 58.9 (10.9) | 56.5 (48.3–62.6) | 15.9 (14.3) | 15 (10–19) | 2 (3.8%) |
| Overall ALS | 1332 | 64.3 (11.3) | 65.3 (59.7–71.8) | 10.8 (10.4) | 9 (5–14) | 70 (5.4%) |
| p=0.0001* | p=0.0001* | p=0.0001† |