Pathophysiology
The affected brain cells are both neurons and glial cells. The neurons display neurofibrillary tangles (NFTs), which are clumps of tau protein, a normal part of a brain cells internal structural skeleton. These tangles are often different from those seen in Alzheimers disease, but may be structurally similar when they occur in the cerebral cortex. Their chemical composition is usually different, however, and is similar to that of tangles seen in corticobasal degeneration. Tufts of tau protein in astrocytes, or tufted astrocytes, are also considered diagnostic. Unlike globose NFTs, they may be more widespread in the cortex. Lewy bodies are seen in some cases, but whether this is a variant or an independent co-existing process is not clear, and in some cases, PSP can coexist with corticobasal degeneration, Parkinsons, and/or Alzheimers disease, particularly with older patients.The principal areas of the brain affected are the:
basal ganglia, particularly the subthalamic nucleus, substantia nigra, and globus pallidus
brainstem, particularly the tectum (the portion of the midbrain where "supranuclear" eye movement resides), as well as dopaminergic nuclei. cerebral cortex, particularly that of the frontal lobes and the limbic system (similarly to frontotemporal degeneration)
dentate nucleus of the cerebellum
spinal cord, particularly the area where some control of the bladder and bowel residesSome consider PSP, corticobasal degeneration, and frontotemporal dementia to be variations of the same disease. Others consider them separate diseases. PSP has been shown occasionally to co-exist with Picks disease. Diagnosis
Magnetic resonance imaging (MRI) is often used to diagnose PSP.
Due to their balance problems and irregular movements, individuals need to spend time learning how to safely transfer in their homes and in the community. This may include rising from and sitting in chairs safely.Due to the progressive nature of this disease, all individuals eventually lose their ability to walk and will need to progress to using a wheelchair. Severe dysphagia often follows, and at this point death is often a matter of months. Prognosis
No effective treatment or cure has been found for PSP, although some of the symptoms can respond to nonspecific measures. The poor prognosis is predominantly attributed to the serious impact this condition has on the quality of life. The average age at symptoms onset is 63 and survival from onset averages seven years with a wide variance. Pneumonia is a frequent cause of death. History
In 1877, Charcot described a 40-year-old woman who had rigid-akinetic parkinsonism, neck dystonia, dysarthria, and eye-movement problems. Chavany and others reported the clinical and pathologic features of a 50-year-old man with a rigid and akinetic form of parkinsonism with postural instability, neck dystonia, dysarthria, and staring gaze in 1951. Progressive supranuclear palsy was first described as a distinct disorder by neurologists John Steele, John Richardson, and Jerzy Olszewski in 1963. They recognized the same clinical syndrome in 8 patients and described the autopsy findings in 6 of them in 1963.Progressive supranuclear palsy was not a “new” disease in 1963, as 22 well-documented case reports had been identified in the neurologic literature between 1877 and 1963.