This very interesting Dutch study compares survival times in 197 PSP patients and 354 FTD patients. Of the 197 PSP patients, 121 were classified as Richardson Syndrome (RS), 7 as PSP-parkinsonism (PSP-P), and the remainder could not be subdivided into a phenotype.
I believe the researchers attempted to limit the FTD causes to those with tau-positive pathology including Pick disease and FTDP-17.
A low percentage of patients participated in brain donation. During the follow-up phase, 133 patients died. Only 24 of them donated brain tissue. All of the PSP patients who died had the RS (Richardson Syndrome) type of PSP. Reading between the lines, it seems that the diagnostic accuracy was over 83%, which is similar to previous studies. If dementia was present, the diagnostic accuracy was over 96%. (The diagnostic accuracy of PSP-P is much lower — in the mid-40s.)
The researchers found that:
* “median survival of PSP patients (8.0 years) was significantly shorter than that of FTD patients (9.9 years).”
* “In PSP, male gender, older onset-age and higher PSP Rating Scale score were identified as independent predictors for shorter survival, whereas in FTD a positive family history and an older onset-age were associated with a poor prognosis.” Older onset age is greater than 72 years.
* “Comparing PSP phenotypes, RS (6.8 years) was found to have a shorter median survival than PSP-P (10.9 years) and the non-conclusive group (8.8 years).”
* The mean “interval between onset and ascertainment [ie, diagnosis]” of PSP was 5.3 years.
* “This study replicates, for the first time, the prognostic value of the PSPRS [PSP Rating Scale] with a sharp increase in probability of death above a score of 60. … Only the subsections supranuclear ocular motor exam, bulbar exam and gait exam were of prognostic value in our study. The replication of Golbe’s findings on the PSPRS has implications for its potential use in clinical trials.”
I’ve copied the abstract below.
Robin
Journal of Neurology, Neurosurgery, & Psychiatry. 2010 Apr;81(4):441-5.
Survival in progressive supranuclear palsy and frontotemporal dementia.
Chiu WZ, Kaat LD, Seelaar H, Rosso SM, Boon AJ, Kamphorst W, van Swieten JC.
Department of Neurology, Erasmus University Medical Centre, Rotterdam, The Netherlands.
Objective
To compare survival and to identify prognostic predictors for progressive supranuclear palsy and frontotemporal dementia.
Background
Progressive supranuclear palsy (PSP) and frontotemporal dementia (FTD) are related disorders. Homozygosity for H1 haplotype is associated with PSP, whereas several MAPT mutations have been identified in FTLD-tau. Survival duration probably reflects underlying pathophysiology or disease.
Methods
Patients with PSP and FTD were recruited by nationwide referral. Survival of 354 FTD patients was compared with that of 197 PSP patients. Cox regression analysis was performed to identify prognostic predictors.
FTLD-tau was defined as Pick disease and FTDP-17 with MAPT mutations. Semiquantitative evaluation of tau-positive pathology was performed on all pathologically proven cases.
Results
The median survival of PSP patients (8.0 years; 95% CI 7.3 to 8.7) was significantly shorter than that of FTD patients (9.9 years; 95% CI 9.2 to 10.6). Corrected for demographic differences, PSP patients were still significantly more at risk of dying than FTD patients.
In PSP, male gender, older onset-age and higher PSP Rating Scale score were identified as independent predictors for shorter survival, whereas in FTD a positive family history and an older onset-age were associated with a poor prognosis.
The difference in hazard rate was even more pronounced when comparing pathologically proven cases of PSP with FTLD-tau.
Conclusion
Survival of PSP patients is shorter than that of FTD patients, and probably reflects a more aggressive disease process in PSP.
Independent predictors of shorter survival in PSP were male gender, older onset-age and higher PSP rating scale score, whereas in FTD a positive family history and higher onset-age were predictors for worse prognosis.
PubMed ID#: 20360166 (see pubmed.gov for this abstract)