Objective: To determine whether patients with ALS-frontotemporal lobar dementia (FTLD) have a shorter survival and are less compliant with recommended treatments than those with ALS who have normal executive and behavioral function (classic ALS).
Methods: Survival analysis from ALS symptom onset to death included 81 of 100 consecutive patients who could be classified definitely as ALS with abnormal executive or behavioral function or as classic ALS. Criteria were defined for compliance with noninvasive positive-pressure ventilation (NPPV) and percutaneous endoscopic gastrostomy (PEG).
Results: Median survival was 2 years 4 months for the 28 patients with FTLD and 3 years 3 months for the 53 patients with classic ALS (relative hazard for death 1.93, CI 1.09 to 3.43; p = 0.024). However, the relative hazard associated with FTLD (1.49) in the multivariate model was diminished by the association of FTLD with bulbar onset and older age and was not significant in this sample size. With bulbar onset, median survival was 2 years 0 months for the 14 with ALS-FTLD and 2 years 10 months for the 10 with classic ALS (relative hazard for death 2.78, CI 1.02 to 7.55; p = 0.045), and older age was not a significant risk. Noncompliance with NPPV and PEG were 75% and 72% in ALS-FTLD, respectively, vs 38% and 31% in classic ALS (relative risks 2.00 and 2.34; p = 0.013 and 0.022).
Conclusions: Survival is significantly shorter among patients with ALS-FTLD than with classic ALS. Furthermore, patients with ALS-FTLD are twice as likely to be noncompliant.