Search for a rare disease
Other search option(s)
Progressive supranuclear palsy-corticobasal syndrome
PSP-corticobasal syndrome (PSP-CBS) is an atypical variant of progressive supranuclear palsy (PSP; see this term), a rare late-onset neurodegenerative disease.
ORPHA:240103Classification level: Subtype of disorder
- PSP-corticobasal syndrome
- Prevalence: 1-9 / 1 000 000
- Inheritance: Not applicable
- Age of onset: Adult
- ICD-10: G23.1
- OMIM: -
- UMLS: -
- MeSH: -
- GARD: -
- MedDRA: -
It is rare, and probably accounts for less than 10% of all cases of PSP-tau pathology, which prevalence is estimated at about 1/16,600.
The disease manifests during the sixth or seventh decade of life with a progressive, often asymmetric dystonia, dyspraxia, and cortical sensory loss. Limb rigidity, bradykinesia and slowed vertical saccadic eye movements are also observed. Postural instability and axial rigidity develop as the disease progresses. The disease is characterized neuropathologically by gliosis with astrocytic plaques, accumulation of tau-immunoreactive neurofibrillary tangles and neuronal loss in specific brain areas, especially in the midfrontal and inferior parietal cortices.
PSP is a 4R tauopathy composed of a preponderance of four-repeat (exon 10 positive) tau isoforms and a characteristic biochemical profile (doublet tau 64 and tau 69). The MAPT H1-clade specific sub-haplotype, H1c, is a risk factor for this disease. The factors that initiate tau-neurodegeneration are unknown.
Diagnosis is based on the clinical picture and neuropsychological evaluation.
Differential diagnosis includes corticobasal degeneration (CBD), Parkinson disease and other atypical parkinsonian disorders (APD) (see these terms).
Management and treatment
There is no treatment curing the disease. Patients do not respond to levodopa treatment. Botulinum toxin and splinting may improve painful dystonic posturing of the hand.
Progressively, patients become wheel-chair dependant due to the frequent falls. Difficulties in breathing and swallowing, and infections are the main causes of death, generally 6-12 years after onset of the disease.
- Clinical genetics review
- English (2010)