How many people are diagnosed with PSP? PSP is considered rare. It is currently estimated that 6 to 10 people per 100,000 are living with PSP. About 30,000 people are diagnosed with PSP in the United States. The numbers for PSP are likely underestimates because many people with PSP are misdiagnosed with another condition, such as Parkinson’ s disease or frontotemporal dementia.
The prevalence for PSP compares to about 1 million with Parkinson’ s disease and 5 million with Alzheimer’ s disease. PSP is slightly more common than amyotrophic lateral sclerosis( called ALS, or Lou Gehrig’ s disease in the U. S. and motor neuron disease elsewhere), although ALS is better known than PSP in that it is easier to diagnose than PSP and often affects much younger people.
We recognize the extra layer of complexities and frustrations that can come along with a rare diagnosis, including healthcare providers who lack familiarity with the disease. One of CurePSP’ s priority goals is to improve awareness of PSP and related diseases among medical professionals and the general public. Such awareness is critical to accurate diagnosis, which allows patients earlier access to specialized management and care, and stimulates interest among researchers, pharmaceutical companies and funding agencies to support the cause and cure of this unique and puzzling illness.
What are the common early symptoms of PSP? PSP can start differently for different people, but there are some commonalities. Balance difficulty, changes to walking, and frequent falls are often the first symptoms for the majority of people with PSP. Other common early symptoms include changes to vision and speech, mild shaking of the hands, difficulty driving a car, and difficulty finding words. Early forgetfulness or personality changes, such as loss of interest in ordinary pleasurable activities, impulsivity, or increased irritability, can also occur and may be misinterpreted as depression or early stage dementia.
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What changes to vision can someone with PSP experience? Changes to vision can be an early symptom of PSP for many people, while for others it does not appear until a few years later. Abnormalities with eye movements is something that neurologists will assess, which is why they often have you follow their finger and move your eyes in different directions without moving your head.
The most common and characteristic eye movement problem in PSP is an impaired ability to move the eyes up or down. Although Parkinson’ s disease, other conditions, and normal aging can sometimes cause difficulty moving the eyes up, PSP is nearly unique in also causing problems moving the eyes down. This problem often takes the form of eye movement apraxia, where the patient can move the eyes up or down only after several requests or with a delay after initiating the effort. This symptom can interfere with looking down at a plate while eating or with descending a flight of stairs, among other things.
Another eye movement problem that starts early in the illness is square wave jerks— rapid, involuntary, right-left movements that interfere with the ability to precisely aim the eyes at a target. Large eye movements can also become jerky rather than smooth.
Because aiming the eyes properly is the main difficulty, reading can become challenging, as a person with PSP may find it hard to automatically shift down from line to line. Some people also have difficulty maintaining eye contact during conversation.