Symptoms include the onset of new weakness or abnormal fatigue in previously affected or unaffected muscles; a general reduction in stamina; muscle and/or joint pain; muscle atrophy; breathing, sleeping, swallowing problems; or cold intolerance. Symptoms may lead to loss of endurance or function.
A diagnosis of PPS assumes the absence of any other condition that could explain the above symptoms. Such conditions should be considered and excluded by appropriate investigations.
The following operational definition of Post Polio Syndrome supports and expands upon the summary definition above. It is derived from consensus statements based on the extensive review of various medical and scientific literature, studies and previous definitions.
As there is no diagnostic test for Post Polio Syndrome it is commonly defined by a symptom complex that includes new muscle weakness, decreased endurance, pain and fatigue.
The onset of PPS may be gradual or it can occur suddenly. It occurs irrespective of ageing. Symptoms may sometimes appear to be triggered by various events like surgery, falls or immobility.
The following are the main criteria that need to be considered in making a diagnosis of “Clinically Definite PPS” or “Clinically Possible PPS”.
Did you know
Polio cases have decreased by over 99% since 1988, from an estimated 350,000 cases then, to 1,604 reported cases in 2009. The reduction is the result of the global effort to eradicate the disease.
There are still countries where it is endemic, these are Afghanistan, India, Nigeria and Pakistan.
Clinically definite PPS
Based on various consensus statements, a diagnosis of “Clinically Definite PPS” comprises a confirmed history and/or physical evidence (however slight) of Polio, a period of functional recovery and stability, new muscle weakness, or abnormal muscle fatigue, with evidence of neurogenic change, and the exclusion of any other possible conditions.
Clinically possible PPS
It is recognised that there are patients who have PPS symptoms, but there is less diagnostic certainty. This would include patients with the following characteristics: a possible history of Polio where there may be no previous physical manifestation, new muscle weakness, or abnormal muscle fatigue, (with no evidence of neurogenic change), a complex of symptoms that are generally recognised to be those for PPS and the exclusion of any other possible conditions.
Clinically definite PPS
Clinically possible PPS
|1. Definite history / physical evidence of Polio||Yes|
|2. History of possible Polio||Yes|
|3. Period of recovery and stability||Yes||Yes|
|4. New muscle weakness – with evidence of neurogenic change||Yes|
|5. New muscle weakness – no evidence of neurogenic change||Yes|
|6. Appropriate complex of symptoms||Yes||Yes|
|7. No other disorder / medical explanation||Yes||Yes|
1. Definite history of Polio/physical evidence
The patient’s original medical records, history and/or physical evidence provide a confirmed diagnosis and history of the original Polio illness.
2. History of possible Polio
Some people may not have confirmation of prior Polio or a physical manifestation of the illness, but do have some history and/or current symptoms, which taken together, indicate a possiblity of Polio.
For example, this could apply to a patient in whose family, or circle of friends, there was an incident of Polio, or who is known to come from an area where there was a Polio epidemic or outbreak, and/or who suffered an illness that at the time was not diagnosed as Polio.
3. Period of recovery and stability
Partial or fairly complete neurological and functional recovery after the original Polio illness followed by a period of neurological and functional stability. As guidance only, the period of stability will generally be 15 years or more.
4. New muscle weakness – with evidence of neurogenic change
Muscle weakness may be confirmed clinically by the presence of clear lower motor neuron features. When and if available/appropriate, EMG testing may confirm this and establish a baseline for repetitive testing or offer an alternative diagnosis. Other tests that may be useful are nerve conduction tests to assess nerve damage, manual muscle testing (MMT), reflex and exercise testing for endurance. Other causes of neuromuscular weakness will also need to be excluded by appropriate tests.
Although it is accepted that electro-diagnostic testing has limitations in confirming neurogenic weakness, and will not provide a definitive diagnosis of new weakness, it may help to exclude some of the other common causes of neurogenic weakness as well as other, more rare, conditions.
5. New muscle weakness – no evidence of neurogenic change
A patient who has a possible history of Polio may be experiencing new weakness that testing cannot confirm to be neurogenic (see point 4) but is consistent with the symptoms of PPS.
6. Appropriate complex of symptoms
These may include two or more of the following health problems occuring after the stable period: extensive general fatigue, abnormal muscle fatigue, decreased endurance, muscle pain, joint pain, new weakness in muscles previously affected or unaffected, new muscle atrophy, functional loss, breathing or swallowing problems, cold intolerance.
7. No other disorder/medical explanation
Exclusion of medical, orthopaedic, and known neurological conditions that might cause the health problems listed in point 6 above, although these other conditions may co-exist with PPS. Depending on symptoms, the most obvious possible causes to rule out are orthopaedic problems related to the original Polio, injuries, breathing problems, other neuromuscular diseases, and other diseases that commonly cause fatigue, such as thyroid problems, diabetes or heart disease.
EMG testing and other relevant tests (see point 4) may be used as a means to exclude other known neurological conditions that may present similar symptoms.