Progressive Supranuclear Palsy (PSP)
What is progressive supranuclear palsy (PSP)?
Progressive supranuclear palsy (PSP) is a brain disorder that is characterized by hindering movement, especially walking. It can also impair speech and the ability to control eye movement. The disease’s name literally means that it worsens (progressive), causes weakness (palsy), and does so by damaging parts of the brain above nerve cells called nuclei (supranuclear).
While it is often underdiagnosed, PSP is estimated to affect between 3 and 6 in every 100,000 people. It usually occurs between ages 45 and 75. Males are affected more than females.
It is important to note that PSP is often misdiagnosed as Parkinson’s Disease because many of its symptoms are like ones that appear in Parkinson’s.
What are the symptoms of progressive supranuclear palsy?
The symptoms of PSP may include, but are not limited to:
- Progressive (steadily worsening) impairment of balance and walking, including a tendency to fall backward
- Slowed movement
- Impaired eye movement, especially downward, and blurry vision
- Difficulty talking and monotonous speech
- Eating and swallowing problems
- Altered mood and behavior
- Depression and apathy, including a loss of interest in activities that used to be pleasurable
- Changes in personality, judgment and thought processes
- Sleep disturbances
What causes progressive supranuclear palsy?
While the exact cause of PSP is unknown, we do know that it results from gradual damage to nerve cells in the brain stem. The big indicator of this disease is the accumulation of abnormal deposits of a protein called tau in brain nerve cells, which causes the cells to malfunction and die.
Very rarely, PSP can be inherited, or occur because of the genes a person inherits from their parents. In those cases, it results from mutations in the MAPT gene, which then gives incorrect instructions for making tau to the nerve cell.
How is progressive supranuclear palsy diagnosed?
PSP is often misdiagnosed as Parkinson’s disease, but people with PSP contradict a Parkinson’s diagnosis because: they don’t have tremors, they have difficulty moving their eyes, and they respond poorly to Parkinson’s medications. The key to diagnosing PSP is identifying its core characteristics: walking instability, difficulty moving the eyes, and impaired talking and swallowing.
The following procedures can lead to a diagnosis:
- Identification of characteristic physical findings
- Clinical evaluation
- Detailed patient and family history
- MRIs may show shrinkage at the top of the brain stem
- A PET scan may identify early signs of brain abnormalities that may not appear on MRIs
What are the treatments for progressive supranuclear palsy?
PSP treatments target symptoms; there is no cure yet for the disease itself. That being said, treatment includes, but is not limited to:
- Administration of antiparkinsonian agents (e.g. levodopa) to treat slowness, but the effect is usually minimal and temporary
- Antidepressant medications
- Botulinum injections to treat excessive eye closing
- Walking aids (e.g. weighted walker in front and shoes with enhanced heels) to help prevent people from falling backwards
- Bifocals or special glasses for treating vision impairment
- Speech and swallowing evaluations, which teach safer swallowing techniques
- If a patient reaches a point where they can no longer swallow, a surgery called percutaneous gastronomy can be performed, in which a tube is placed through the skin of the abdomen into the stomach to allow for sufficient feeding.
- Physical and occupational therapy
Where can I find out more about progressive supranuclear palsy?