The risk of aspiration is aggravated by the tendency to overload the mouth or to take big gulps of beverages because of a loss of inhibition or a reckless impulsiveness that can be partly involuntary.
Does PSP lead to dementia as in Alzheimer’ s disease?
Most patients do eventually develop some degree of mental impairment during the course of the disease. Some, however, are mislabeled as having Alzheimer’ s disease. This is not unlike the situation in Parkinson’ s disease.
Dementia in PSP, if it does occur, does not feature the memory problem that is so apparent in Alzheimer’ s disease. Rather, the dementia of PSP is characterized by slowed thought, difficulty resisting impulses, and difficulty synthesizing several different ideas into a new idea or plan. These mental functions are performed mostly by the front part of the brain( the frontal lobes). In Alzheimer’ s, on the other hand, the problem is mostly in the part of the brain just above the ears( the temporal lobes), where memory functions are concentrated.
Alzheimer’ s disease also includes either difficulty with language( such as trouble recalling correct names of common objects) or difficulty finding one’ s way around a previously familiar environment. Fortunately, these symptoms almost never occur in PSP. Nevertheless, these problems can interfere to a major degree with the ability to function independently, and the patient’ s irritability in some cases can make it difficult for caregivers to help.
Slowing of thought can cause major problems for people with PSP by making it difficult to partake in conversation. A question may be answered with great accuracy and detail, but with a delay of several seconds to minutes. Probably the most important aspect of PSP dementia is apathy. People with PSP seem to lose interest in their surroundings, creating the impression of lost thinking ability and interfering with family interactions.
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How is PSP different from Parkinson’ s disease?
Both PSP and Parkinson’ s disease cause parkinsonism( with a small p)— a combination of stiffness, slowness, and clumsiness. This is why PSP may be difficult to distinguish from Parkinson’ s disease early on. However, shaking( tremor), while prominent in about 70 % of people with Parkinson’ s disease, occurs in only about 10 % of people with PSP. A more common type of tremor occurring in PSP is irregular, mild, and present only when the hands are in use, not at rest as in Parkinson’ s disease.
Patients with PSP usually stand up straight or occasionally even tilt the head backwards and tend to fall backwards, while those with Parkinson’ s usually are bent forwards. The problems with vision, speech, and swallowing are much more common and severe in PSP than in Parkinson’ s. Parkinson’ s causes more difficulty using the hands and more stiffness in the limbs than does PSP. Finally, the medications that are so effective for Parkinson’ s disease offer much less benefit in PSP. The PSP-parkinsonism variant of PSP is more likely than typical PSP to have a tremor, to involve one side of the body more than the other, to have less of a problem with vision and swallowing, and to respond better to drugs for Parkinson’ s.
Most drugs for Parkinson’ s disease enhance, replace, or mimic a brain chemical called dopamine. Parkinson’ s responds better to such drugs than does PSP because dopamine deficiency is by far Parkinson’ s most important abnormality. In PSP, deficiencies of several other brain chemicals are at least as severe as the dopamine deficiency, and no good way exists to replace those. Also, in PSP, there is damage to the brain cells that receive the dopamine-encoded messages, while these remain intact in Parkinson’ s.