The levels of evidence (class I-IV) supporting the recommendations and ratings of recommendations (A-C, Good Practice Points) are defined at the end of the "Major Recommendations" field.
Diagnostic Criteria
The Task Force suggests that the criteria for post-polio syndrome (PPS) used within European Federation of Neurological Societies (EFNS) and Europe should be based on the Halstead's definition from 1991 with emphasis on the new muscle weakness (refer to the original guideline document for details). The diagnosis of PPS is an exclusion diagnosis with no test or analysis specific for PPS, and the role of the investigation is to rule out every other possible cause for the new symptoms and clinical deterioration.
Therapeutic Interventions
Level A Recommendations
A small number of controlled studies of potential specific treatments for PPS have been completed, but no definitive therapeutic effect has been reported for the agents evaluated (pyridostigmine, steroids and amantadine).
Level B Recommendations
Supervised muscular training, both isokinetic and isometric, is a safe and effective way to prevent further decline of muscle strength in slightly or moderately weak muscle groups and can even reduce symptoms of muscular fatigue, muscle weakness and pain in selected post-polio patients. There are no studies evaluating the effect of muscular training in patients with severe weakness and the long-term effects of such training are not yet explored. Precautions to avoid muscular overuse should be taken with intermittent breaks, periods of rest between series of exercises and submaximal work load.
Training in a warm climate and non-swimming water exercises are particularly useful.
Level C Recommendations
Recognition of respiratory impairment and early introduction of non-invasive ventilatory aids prevent or delay further respiratory decline and the need of invasive respiratory aids.
Respiratory muscle training can improve pulmonary function.
Group training, regular follow-ups and patient education are useful for the patients' mental status and well-being.
Good Practice Points
Weight loss and adjustment and introduction of properly fitted assistive devices; but lack significant scientific evidence.
Definitions:
Evidence Classification Scheme for a Diagnostic Measure
Class I: A prospective study in a broad spectrum of persons with the suspected condition, using a "gold standard" for case definition, where the test is applied in a blinded evaluation, and enabling the assessment of appropriate tests of diagnostic accuracy
Class II: A prospective study of a narrow spectrum of persons with the suspected condition, or a well-designed retrospective study of a broad spectrum of persons with an established condition (by "gold standard") compared to a broad spectrum of controls, where test is applied in a blinded evaluation, and enabling the assessment of appropriate tests of diagnostic accuracy
Class III: Evidence provided by a retrospective study where either persons with the established condition or controls are of a narrow spectrum, and where test is applied in a blinded evaluation
Class IV: Any design where test is not applied in blinded evaluation OR evidence provided by expert opinion alone or in descriptive case series (without controls)
Evidence Classification Scheme for a Therapeutic Intervention
Class I: An adequately powered prospective, randomized, controlled clinical trial with masked outcome assessment in a representative population or an adequately powered systematic review of prospective randomized controlled clinical trials with masked outcome assessment in representative populations. The following are required:
- Randomization concealment
- Primary outcome(s) is/are clearly defined
- Exclusion/inclusion criteria are clearly defined
- Adequate accounting for dropouts and crossovers with numbers sufficiently low to have minimal potential for bias
- Relevant baseline characteristics are presented and substantially equivalent among treatment groups or there is appropriate statistical adjustment for differences
Class II: Prospective matched-group cohort study in a representative population with masked outcome assessment that meets a–e above or a randomized, controlled trial in a representative population that lacks one criteria a–e
Class III: All other controlled trials (including well-defined natural history controls or patients serving as own controls) in a representative population, where outcome assessment is independent of patient treatment
Class IV: Evidence from uncontrolled studies, case series, case reports, or expert opinion
Rating of Recommendations for a Diagnostic Measure
Level A rating (established as useful/predictive or not useful/predictive) requires at least one convincing class I study or at least two consistent, convincing class II studies.
Level B rating (established as probably useful/predictive or not useful/predictive) requires at least one convincing class II study or overwhelming class III evidence.
Level C rating (established as possibly useful/predictive or not useful/predictive) requires at least two convincing class III studies.
Rating of Recommendations for a Therapeutic Intervention
Level A rating (established as effective, ineffective, or harmful) requires at least one convincing class I study or at least two consistent, convincing class II studies.
Level B rating (probably effective, ineffective, or harmful) requires at least one convincing class II study or overwhelming class III evidence.
Level C rating (possibly effective, ineffective, or harmful) requires at least two convincing class III studies.
Good Practice Points When only class IV evidence was available but consensus could be reached the Task Force gives recommendations as good practice points.
