Medical research

The post-polio program affiliated with McGill University continues its work in clinical care of post-polio patients, education and clinical research on post-polio syndrome (PPS) and the late effects of polio.

Post-Polio Clinic Research

Here is a summary of recent published research from the Post-Polio Clinic at the Montreal Neurological Institute and Hospital. Thanks to ^Dr. Trojan and ^Dr. Kaminska for sending us these summaries

Study of Intravenous Immunoglobulin in Post-Polio Syndrome Patients

Summary prepared by Dr. Daria A. Trojan, Physiatrist and Adriana Venturini, pht, PhD (candidate)
June 2025

Post-Polio Syndrome (PPS) affects a large proportion of people who have had paralytic polio. Currently there are no treatments to cure PPS. The results from this study present a possible future avenue for treatment. The question asked by the researchers involved in this study was whether administering immunoglobulin intravenously (IvIg) for one year to a person living with the symptoms of PPS would lead to better functioning as compared to not receiving IvIg. In addition, during this study the safety of IvIg (Flebogamma® 5% DIF) was evaluated. To obtain the answer, Instituto Grifols, S.A. funded a study across 22 centres in Europe, the USA and Canada whereby one hundred and ninety-one participants were randomly administered IvIg or an inactive substance (placebo). The study started in 2014 at the Montreal Neurological Institute-Hospital, the only Canadian site to participate, enrolling 25 participants with PPS. The last participant completed the study in November 2022. The analysis of the data is ongoing, but the preliminary results were announced in March 2025 with a press release from the Institute Grifols, S.A.

The early results of this study indicate that people who received the IvIg for one year were able to walk further on a test that measures walking distance, the 2-minute walk test. The people who received IvIg (1 g/kg) walked an average of 6.07 metres more on the 2-minute walk test than those who did not receive the IvIg. This is an important difference, as determined by statistical analysis and was also considered to be important for patient functioning. The 2-minute walk test is used as an indicator of functional ability and is especially relevant for people living with PPS since for most the legs or a leg are the main part of the body affected by PPS symptoms.

Early results also show that study participants with PPS who received IvIg (1g/kg) were able to walk further on the 6-minute walk test, a measure of endurance. However, the extra average 15.8 meters walked by people who received IvIg was not a statistically important difference when compared to the group of participants that did not receive IvIg.

IvIg treatment for PPS patients was shown to be safe with a similar safety profile as seen in other patient populations who are treated with this product.

These initial results are encouraging news for PPS patients. The early results indicate the potential for a new avenue of treatment for people living with the symptoms of post-polio syndrome after polio.

The study data analysis is still in progress, and the results require review by experts in the area and appropriate agencies before subsequent steps can take place to potentially make this product available as a clinical treatment.

To Improve Respiratory Health

Some people who have suffered from polio may have decreased respiratory function. This problem affects those who are left with a deformity of the rib cage or weakness of the respiratory muscles (such as the diaphragm). These people may not have any breathing problems felt for a long time. However, with age, respiratory function deteriorates and difficulties may arise. Additionally, people with post-polio syndrome may have an accelerated loss of muscle strength, potentially including respiratory muscles.

A team of researchers from the Montreal Neurological Institute and the Royal Victoria Hospital (McGill University Health Centre), attached to the post-polio clinic of the Montreal Neurological Hospital, is currently conducting a research project aimed at improve the lung health of people with post-polio syndrome who show the onset of loss of lung function. Two other diseases are also targeted by this study, namely Steinert’s dystrophy and amyotrophic lateral sclerosis. This project is about an exercise for the respiratory system – the “Manual Hyperinflation Technique”. This involves blowing a certain amount of air into the lungs using a balloon (similar to the one used for resuscitation), as if the person were taking a deep breath. The quantity of air thus insufflated somewhat exceeds the volume that the person could inhale on their own, given their muscular weakness. This makes it possible to “recruit” maximum lung capacity. It’s like physiotherapy for the lungs. The exercises aim to maintain or increase the flexibility of the lungs and rib cage. These tend to stiffen when not fully utilized, which is the case when there is some weakness in the respiratory muscles. The exercises aim to maintain or increase the flexibility of the lungs and rib cage. These tend to stiffen when not fully utilized, which is the case when there is some weakness in the respiratory muscles. The exercises aim to maintain or increase the flexibility of the lungs and rib cage. These tend to stiffen when not fully utilized, which is the case when there is some weakness in the respiratory muscles.

These exercises are very safe. Their main drawback is the time required to perform them – for optimal effect three to four sessions per day are suggested. People with more severe impairment of the strength of the respiratory muscles with various neurological diseases already practice these exercises routinely. In addition to increasing the flexibility of the lungs and rib cage and therefore facilitating breathing, they improve the strength of coughing, which makes it easier to clear secretions and potentially reduce the risk of pneumonia in these patients. These exercises have never until now been formally studied to find out if they can help prevent the deterioration of breathing. The current study is innovative because its goal is to demonstrate a beneficial effect for people with only mild impairment of their respiratory function. Ultimately, it is possible that these exercises may slow the progression of deterioration in respiratory function. When there is more marked loss of strength and inability to breathe, nocturnal respiratory support is required using a ventilator which is a machine that pushes air through a nasal or naso-oral mask, similar machines used for sleep apnea (PPC or « CPAP »). The ventilator provides adequate oxygen and CO2 exchange by assisting the patient’s weakened muscles with each breath.

People who participated in this study generally enjoyed the experience. It is too early to draw conclusions about the effectiveness of exercises on physiological measures, but the preliminary results are encouraging. At least some people notice an improvement in their breathing and endurance, and it appears that the reported benefits are greater in those with post-polio syndrome compared to the other two diseases studied. No complications were observed. The researchers are therefore confident that these exercises can really have a positive impact on people with weak respiratory muscles, particularly people with post-polio syndrome. They continue to seek candidates for this project.

Researchers : The physicians collaborating in this project are Dr. Daria Trojan, Dr. Angela Genge, Dr. Basil Petrof and Dr. Marta Kaminska. The respiratory therapist who specializes in this technique and who oversees its teaching is Franceen Browman. The research coordinator is Christine Kupka. Text written by Marta Kaminska MD, FRCP(C), McGill University Health Centre, Respiratory Division, Montreal. Originally published in Folio Polio, no45, Winter 2010-2011.

Sleep Disordered Breathing in Post-Polio Clinic Patients with Fatigue

The objective of this study was to determine the frequency, predictive factors as well as symptoms that can predict sleep disordered breathing in post-polio clinic patients.

This study involved a review of 590 records available at the post-polio clinic. We concluded that sleep-disordered breathing, particularly obstructive sleep apnea-hypopnea, was very common in post-polio clinic patients who were referred for sleep assessment. This condition often appeared even in patients who had no history of polio-related breathing difficulty. Snoring was the only symptom that could predict sleep disordered breathing. This disorder is best diagnosed when we do an overnight sleep study in the laboratory. With proper treatment, people with sleep-disordered breathing can experience significant improvement in symptoms.

If an individual who has had polio in the past experiences fatigue or drowsiness atypical (unusual) for post-polio syndrome as well as other symptoms suggestive of sleep-disordered breathing, we recommend that they discuss their symptoms with their doctor. . An evaluation at a sleep clinic may be required.

Reference: Dahan V, Kimoff J, Petrof B, Benedetti A, Diorio D, Trojan DA. Sleep disordered breathing in fatigued post-polio clinic patients. Archives of Physical Medicine and Rehabilitation 2006;87:1352-1356.

Osteoporosis in patients at the post-polio clinic

The purpose of this research was to determine the frequency of osteoporosis in the hip and lumbar spine (lower back) in post-polio clinic patients, and to assess the relationship between muscle strength and other factors with hip bone density.

The study involved reviewing the medical records of 379 patients at our institution’s post-polio clinic. Of these, 164 patients met the study criteria, including the results of a bone densitometry. This preliminary study allowed us to conclude that osteoporosis and osteopenia at the hip level occur frequently in patients in the post-polio clinic who were referred for bone densitometry. In the patients included in our study, osteoporosis and osteopenia of the hip frequently appeared in men as well as in women in the pre and post menopause phases. We found a relationship between hip bone density and leg muscle strength for which bone density was assessed: the weaker the leg,

Based on these results, we recommend that all patients with a history of paralytic poliomyelitis be evaluated for osteoporosis in both hips (or preferably the hip of the weaker extremity) and in the lumbar spine. . It is possible that appropriate treatment increases bone mineral density, although this question was not part of our study and has not been specifically evaluated in patients with a history of paralytic poliomyelitis. Further research on this issue is ongoing.

Reference : Haziza M, Kremer R, Benedetti A, Trojan DA. Osteoporosis in a post-polio clinic population. Archives of Physical Medicine and Rehabilitation. 2007;88:1030-1035.

Elevated serum markers of inflammation in people with post-polio syndrome

The aim of this study was to determine whether serum inflammatory markers are increased in patients with post-polio syndrome compared to a healthy control group. We also wanted to know if there is an association between elevated markers of inflammation and clinical symptoms.

In this cross-sectional study, we compared 51 people with post-polio syndrome with 26 people in the control group. We found that the serum (blood) inflammatory markers TNF-α, IL-6 and leptin were increased in patients with post-polio syndrome compared to control individuals. We also found a relationship between TNF-α levels and pain, more specifically muscle pain, in patients with post-polio syndrome.

Due to the nature of our study, which involved only one evaluation, we cannot conclude that inflammatory markers are a cause of pain in patients with post-polio syndrome. However, our results raise the possibility that markers of inflammation may become important for the study of clinical symptoms of post-polio syndrome. We recommend that further studies be conducted on the role of inflammatory markers in the pathophysiology of post-polio syndrome.

Reference : Fordyce CB. Gagne D, Jalili F, Alatab S, Arnold DL, Da Costa D, Sawoczczuk S, Bodner C, Shapiro S, Collet JP, Le Cruguel JP, Robinson A, Lapierre Y, Bar-Or A, Trojan DA. Elevated serum inflammatory markers in post-poliomyelitis syndrome. Journal of the Neurological Sciences 2008;271:80-86.)

Fatigue in post-polio syndrome: relationship between factors associated with the disease, behavioral factors and psychosocial factors

The objective of this study was to determine which factors are associated with general, physical and mental fatigue in patients with post-polio syndrome, and to assess the influence of possibly modifiable factors on fatigue. Several factors related to illness, behavior and psychosocial factors were considered.

This study, conducted among 52 outpatients with post-polio syndrome, was cross-sectional. We found that in several multivariate statistical models, the important factors that allow us to predict general fatigue are reduced respiratory muscle strength, the presence of fibromyalgia, decreased extremity muscle strength, and increased stress and depression. Important factors that predict physical fatigue are reduced respiratory muscle strength, decreased extremity muscle strength, increased age, decreased time since poliomyelitis, reduced activity physical and increased pain. An important indicator of mental fatigue is an increase in stress.

We concluded that there are different types of fatigues in patients with post-polio syndrome and that different variables are important depending on the different types of fatigue. Potentially modifiable factors (such as stress, depression, pain, and physical activity) account for some of the fatigue in patients with post-polio syndrome.

Because this study was cross-sectional, it is impossible for us to conclude that these factors are causes of fatigue. However, because many of the factors identified are subject to treatment, our results suggest that with adequate treatment, it is possible to improve the state of fatigue. Because several potentially modifiable factors have been identified as being important for both general and physical fatigue, our results suggest that an interdisciplinary rehabilitation program that places the focus on contributing factors for these types of fatigue.

Reference : Trojan DA, Arnold D, Collet JP, Shapiro S, Bar-Or A, Robinson A, Le Cruguel JP, Ducruet T, Narayanan S, Arcelin K, Tartaglia MC, Caramanos Z, Da Costa D. Fatigue in post-poliomyelitis syndrome: association with disease-related, behavioral, and psychosocial factors. Physical Medicine and Rehabilitation 2009;1:442-449.

Brain volume and fatigue in patients with post-poliomyelitis syndrome

The objective of this study was to determine whether patients with post-polio syndrome (PPS) have a lower brain volume than normal subjects. We also wanted to determine if there is a link between brain size and fatigue in PPS patients.

Acute polio is associated with encephalitis (or inflammation of the brain). It is possible that brain inflammation at a young age can produce permanent neuronal damage with loss of brain volume leading to symptoms such as fatigue. Brain volume loss in other neurological diseases has been associated with clinical symptoms such as decreased cognitive function and fatigue. The project was a cross-sectional study of 49 patients with PPS, 28 people in the control group and 53 patients with multiple sclerosis (MS). Patients with MS were the positive control of the research protocol, as it has already been shown that brain volume decreases with MS. All subjects in the study underwent magnetic resonance imaging (MRI) of their brain and the calculation of its volume was made by automated software: « Structured Image Evaluation, using Normalization, of Atrophy method (SIENAx) » ( Method for assessing atrophy by structured image analysis using normalization). This assessment method may not detect brain volume loss in a region such as the brainstem. Subjects also completed the Fatigue Severity Scale (FSS). Imaging of adequate quality was available for 42 patients with PPS, 27 in the control group and 49 patients with MS. of Atrophy method (SIENAx)” (Method for the evaluation of atrophy by the structured analysis of the image thanks to normalization). This assessment method may not detect brain volume loss in a region such as the brainstem. Subjects also completed the Fatigue Severity Scale (FSS). Imaging of adequate quality was available for 42 patients with PPS, 27 in the control group and 49 patients with MS. of Atrophy method (SIENAx)” (Method for the evaluation of atrophy by the structured analysis of the image thanks to normalization). This assessment method may not detect brain volume loss in a region such as the brainstem. Subjects also completed the Fatigue Severity Scale (FSS). Imaging of adequate quality was available for 42 patients with PPS, 27 in the control group and 49 patients with MS.

We found that the volume of patients with PPS was not significantly different from the control group. As demonstrated by previous research, we have found significant brain volume loss in MS patients. We found no link between brain volume and fatigue in patients with PPS. Our results indicate that brain atrophy is not a significant problem for patients with PPS and is unlikely to be a contributory factor to the symptom of fatigue in patients with this syndrome.

Reference : Trojan DA, Narayanan S, Francis SJ, Caramanos Z, Robinson A, Cardoso M, Arnold DL. Brain volume and fatigue in post-poliomyelitis syndrome patients. Physical Medicine and Rehabilitation 2013 doi: 10.1016/j.pmrj.2013.09.009 (Epub ahead of print)

Thanks

These studies involved a large number of co-investigators who are presented here as authors. These studies were supported by the Polio Quebec Association, the Multiple Sclerosis Society of Canada (operational fund) and the Montreal Neurological Institute (salary). We are grateful to the patients and members of the control group who gave their time to participate in these studies.