Progressive Supranuclear Palsy (PSP)
by André Delacourte
Progressive Supranuclear Palsy is a disorder caused by damage to certain nerve cells in the brain, characterised by progressive lack of coordination, stiffness of the neck and trunk, difficulties with eye movement, slow movements, cognitive dysfunction, and difficulty walking that can result in falls. This disease is most often seen in people over 60 years old.
Symptoms and course
PSP is a very individual disease, affecting different people in different ways at different rates of progression.
Early symptoms in 'classical' PSP cases involve a tendency to fall unexpectedly, usually backwards. Other common symptoms include rigidity and backward arching of the neck, and - a key diagnostic feature - the Supranuclear Palsy. This is a difficulty in ‘willed’ upgaze and downgaze, ie. the ability of the patient to voluntarily move their eyes up and down whilst keeping the head still.
The gait of a PSP patient is mildly unsteady and broad based. PSP is a disorder characterised by symptoms similar to Parkinson’s disease (including unsteady gait, stiff movements and mild dementia). PSP can be easily misdiagnosed as Parkinson’s disease in its early stages. Tiny, cramped handwriting and some changes in personality are often other indicators of the disease.
Cognitive symptoms include reduced verbal fluency, attention deficit, executive dysfunction, slowing of information processing and problems with complex and abstract thought. Nevertheless the patient is still very much aware of what is going on. Behavioural changes include emotional liability and temper outbursts.
Motor symptoms come first and always precede cognitive changes.
The progression of the disease is slow between 5 to 10 years. The age of onset is typically over 50 years old. The duration of the disease is 7 years.
Causes and risk factors
The cause of PSP is as yet unknown, though there may be a genetic, as well as an environmental, component.
From a broad survey of various countries in the Western World, the probability of the disease being passed from one generation to the next within a family is extremely low. It may be that a combination of complex genetic susceptibility to PSP, together with an environmental trigger such as a blow on the head or exposure to toxins may cause the onset, but more research is required to confirm this theory. However, as observed in many neurodegenerative disorders, tau proteins or tau gene is likely a significant causal factor. Indeed, there is a genetic risk factor linked to H1H1 haplotype in the tau gene.
PSP belongs to the 4R tauopathies (aggregation of tau isoforms with 4 repeats) (Sergeant N. et al, 1999).
A genetic risk factor linked to tau gene (Baker M. et al, 1999).
Prevalence estimations vary between 1.4 /100.000 (Tolosa - E) to 6/100.000.
No specific tests. Brain imaging non specific. Poor response to Parkinsonian drugs argues against Parkinson's.
Care and treatment
Treatment is aimed at controlling symptoms. There is no known cure for progressive supranuclear palsy. Levodopa and anticholinergic medications may provide temporary reduction of symptoms.
These are not as effective as in Parkinson´s disease, however.
Ongoing research / clinical trials
Two multicentre European trials have been launched to evaluate the effects of riluzole (NNIPPS see in PSP file) and human recombinant growth hormone on disease progression in MSA.
A randomised, multicentric, double blind, placebo controlled, stratified, parallel group study.
Acronym: NNIPPS (Neuroprotection & Natural History in Parkinson Plus Syndromes
- Dr G. Bensimon, Dept. de Pharmacologie, Hôpital de la Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, Paris, France
- Prof. PN. Leigh, Dept Clinical Neuroscience, Institute of Psychiatry & Guy’s, King’s & Thomas’s School of Medicine (GKT), London, UK
- Prof. A. Ludolph, Dept of Neurology, Universitätsklinik and Rehabilitation Krankenhaus Ulm, Ulm, Germany)
PSP Europe The Old Rectory, Wappenham Towcester Northants NN12 8SQ Tel: + 44 1327 860299 Fax: + 44 1327 861007 firstname.lastname@example.org http://www.pspeur.org
- Baker M., Litvan I., Houlden H., Adamson J., Dickson D., Perez-Tur J., Hardy J., Lynch T., Bigio E. and Hutton M. (1999) Association of an extended haplotype in the tau gene with progressive supranuclear palsy. Hum Mol Genet 8, 711-715.
- Litvan I. (2001) Diagnosis and management of progressive supranuclear palsy. Semin Neurol 21, 41-48.
- Litvan I. (2003) Update on epidemiological aspects of progressive supranuclear palsy. Mov Disord 18 Suppl 6, S43-50.
- Sergeant N., Wattez A. and Delacourte A. (1999) Neurofibrillary degeneration in progressive supranuclear palsy and corticobasal degeneration: tau pathologies with exclusively exon 10 isoforms. J Neurochem 72, 1243-1249.
- Tolosa E., Valldeoriola F. and Marti M. J. (1994) Clinical diagnosis and diagnostic criteria of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome). J Neural Transm Suppl 42, 15-31.
Last Updated: vendredi 09 octobre 2009