What are the most common early symptoms of PSP?
Balance difficulty, usually with falls, is the first symptom in a majority of people. Other common early symptoms can be misinterpreted as depression or even as senility. These include forgetfulness and personality changes, such as loss of interest in ordinary pleasurable activities or increased irritability. Less common early symptoms are trouble with eyesight, slurred speech, mild shaking of the hands, and difficulty driving a car. Freezing of gait can be a first and only symptom for several years and difficulty finding words, or aphasia, can be a first and most prominent issue.
Are there other, rare types of PSP?
Another type, called corticobasal syndrome, affects limbs on one side of the body far earlier and more severely than on the other side. It is a rare type that was described only in 2018, mostly in Japan, and starts with ataxia, which is a specific type of coordination problem arising from the cerebellum and resembling drunkenness. Most people with these minority phenotypes eventually do develop the more classic signs and symptoms of PSP.
What happens next?
The name of the disease includes the word“ progressive” because, unfortunately, the early symptoms get worse and new symptoms develop over time. After five or six years, on average, the imbalance and stiffness worsen to make walking very difficult or impossible. Trouble with eyesight eventually develops in almost all cases and can sometimes be as disabling as the movement difficulty. Difficulty with speech and swallowing are additional important features of PSP that eventually occur in most patients.
What does the name“ supranuclear palsy” mean?
In general, palsy is a weakness or paralysis of a part of the body. The term“ supranuclear” refers to the nature of the eye problem in PSP. Although some patients with PSP describe their symptom as blurring, the actual problem is an inability to aim the eyes properly because of weakness or paralysis( palsy) of the muscles that move the eyeballs. These muscles are controlled by nerve cells residing in clusters or nuclei near the base of the brain, in the brainstem. Most other brain problems that affect the eye movements originate in those nuclei, but in PSP the problem originates in parts of the brain that control those eye-movement nuclei. These“ higher” control areas are what the prefix supra in supranuclear refers to.
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Is the visual problem the most important part of PSP?
In most cases, the visual problem is at least as important as the walking difficulty, though it does not typically appear until three to five years after. Because aiming the eyes properly is the main difficulty, reading often becomes challenging. The patient finds it hard to automatically shift down from line to line. This is very different from just needing reading glasses. An eye doctor unfamiliar with PSP may be baffled by the patient’ s complaint of being unable to read a newspaper despite normal ability to read the individual letters on an eye chart. Some patients have their mild cataracts extracted in a vain effort to relieve such a visual problem.
Another common visual problem is an inability to maintain eye contact during conversation. This can give the mistaken impression that the patient is senile, hostile, or uninterested. The same eye movement problem can create the symptom of tunnel vision and interfere with driving a car.