3 Forms of PSP – RS, PSP-P, and PPFG

The Society for PSP had an International PSP Resarch Symposium on 11/17/05, right after the annual meeting of the Society for Neuroscience in Washington, DC.  The latest issues of the PSP Advocate has an interesting series of articles on some of the presentations made by scientists at the Symposium.

One scientific abstract I found worthwhile was written by David Williams, MBBS, FRACP, of the Queen Square Brain Bank (QSBB), the Sara Koe PSP Research Center, etc., London.

Dr. Williams said that clinicians can use some key differences between PD and some types of PSP in differentiating PD from some types of PSP in a clinical setting.  Specifically, the “timing of falls, the presence of visual hallucinations and testing of smell should be helpful in distinguishing PSP-P and PPFG from PD.”  (PD patients start falling later, nearly half have sustained visual hallucinations, and a decreased sense of smell.)

Also, he identified three distinct types of PSP:

  • Richardson’s Syndrome (RS):  early onset of postural instability and falls, gaze difficulties, and dementia.  54% of cases in the study.
  • PSP-parkinsonism (PSP-P):  non-symmetrical symptom onset, tremor, and a moderate initial therapeutic response to levodopa.  32% of cases in the study.  Obviously this type is often confused with Parkinson’s Disease.
  • Primary progressive freezing gait (PPFG):  early onset of gait freezing without other neurological signs. 4% of cases in the study.

Here are some excerpts from the scientific abstract about survival time and other symptoms:

“…We have recently identified two apparently distinct clinical types of PSP by analyzing clinical case notes of patients with a pathological diagnosis, archived at the Queen Square Brain Bank, London. We have named these two clinical types: Richardson’s syndrome (RS) and PSP-Parkinsonism (P).

Disease duration in RS was shorter (average 5.9 vs. 9.1 years), falls occurred earlier and age at death was younger (72.1 vs. 75.5 years) than in PSP-P. …

Primary progressive freezing gait (PPFG) … had longer disease duration (average 12.8 years) and late onset of gaze palsy and dementia compared with RS.

Other clinical analysis at QSBB has shown that sustained visual hallucinations are exceedingly rare in PSP (3%), but relatively common in Parkinson’s disease (PD, 49%). A decreased sense of smell is usual in Parkinson’s disease but not common in PSP. The time from symptom onset to first fall is early in PSP: 57% of patients with PSP fall within two years, 
compared to 6% with PD. The timing of falls, the presence of visual hallucinations and testing of smell should be helpful in distinguishing PSP-P and PPFG from Parkinson’s disease in the clinic…”

You can find this scientific abstract and the related lay abstract along with all the other articles online at: