Aging in polio

Prevalence and Severity of Central Sensitization in Post-Polio Syndrome: Associations with Clinical Measures and Quality of Life

OBJECTIVES

To investigate the presence and severity of central sensitization (CS) and its associations with clinical measures and quality of life (QoL) in individuals with a history of paralytic poliomyelitis with and without post-polio syndrome (PPS).

METHODS

In this cross-sectional study, we included 98 individuals with a history of poliomyelitis, in whom 82 (83.6%) met the criteria of PPS. We used CS Inventory (CSI) to evaluate the presence and severity of CS. We evaluated the severity of fatigue, pain, polio-related impairments, and QoL using a Numerical Rating Scale in addition to Fatigue Severity Scale, Self-reported Impairments in Persons with late effects of Polio rating scale (SIPP), and Nottingham Health Profile (NHP).

RESULTS

CS was present in 52.4% of patients with PPS, of which 63% are classified as severe to extreme. Those with CS reported more severe symptoms, more polio-related impairments, and worse QoL than those without CS. Severity of CS showed significant positive correlations with severity of fatigue, pain, SIPP, and NHP scales in those with PPS. CSI did not indicate CS in any of those without PPS.

CONCLUSION

CS was present in more than half of the individuals with PPS and correlated with more severe pain, fatigue, and more polio-related impairments, in addition to poorer QoL. These findings suggest that CS may contribute to the clinical picture in a subgroup of individuals with PPS. Thus, identification and appropriate management of CS patients may potentially help alleviate their symptoms and improve their QoL.

Nerve Conduction Study/Electromyography: Common Neuropathies and Considerations for Patients with Polio

Acute poliomyelitis is now extremely rare in the United States. Worldwide there are still sporadic outbreaks, which are typically treated with acute inoculation programs. Although polio has effectively been eradicated, the full scope of the disease and its myriad manifestations both in the acute phase and in the postpolio syndrome phase, remain areas of fertile research, debate, and stimulating topics.

Postpolio Syndrome: A Review of Lived Experiences of Patients

Postpolio syndrome (PPS) refers to a group of conditions that are present in patients, years after recovery from initial acute paralytic poliomyelitis. About 15%-80% of 20 million polio survivors worldwide will experience exacerbation of symptoms which typically appear 15-30 years after the resolution of initial poliomyelitis. Symptoms include new muscle weakness, fatigue, myalgia, joint pain, dysphagia, and difficulty breathing. Other reported symptoms include cold intolerance, sleep disorder, dysphonia, loss of stamina, musculoskeletal deformities, cardiovascular disorders, psychosocial problems, and restless legs syndrome. These symptoms are attributed to the superimposed neuronal loss of aging with inflammatory mechanisms, but without any convincing evidence of viral reactivation. Risk factors include female gender, respiratory symptoms, normal aging, permanent disability caused by motor neuron damage, muscle overuse and disuse, aging, and immunologic mechanisms. Hypothyroidism-induced myopathy and fibromyalgia are a differential diagnosis for PPS, and exclusion diagnosis is required as confirmatory criteria for PPS. The symptoms of PPS presented determine the course of management.

Cortical hypoactivation during resting EEG suggests central nervous system pathology in patients with chronic fatigue syndrome

We investigated central fatigue in 50 patients with chronic fatigue syndrome (CFS) and 50 matched healthy controls (HC). Resting state EEG was collected from 19 scalp locations during a 3 min, eyes-closed condition. Current densities were localized using exact low-resolution electromagnetic tomography (eLORETA). The Multidimensional Fatigue Inventory (MFI-20) and the Fatigue Severity Scale (FSS) were administered to all participants. Independent t-tests and linear regression analyses were used to evaluate group differences in current densities, followed by statistical non-parametric mapping (SnPM) correction procedures. Significant differences were found in the delta (1-3 Hz) and beta-2 (19-21 Hz) frequency bands. Delta sources were found predominately in the frontal lobe, while beta-2 sources were found in the medial and superior parietal lobe. Left-lateralized, frontal delta sources were associated with a clinical reduction in motivation. The implications of abnormal cortical sources in patients with CFS are discussed.

Denervation causes fiber atrophy and myosin heavy chain co-expression in senescent skeletal muscle

Although denervation has long been implicated in aging muscle, the degree to which it is causes the fiber atrophy seen in aging muscle is unknown. To address this question, we quantified motoneuron soma counts in the lumbar spinal cord using choline acetyl transferase immunhistochemistry and quantified the size of denervated versus innervated muscle fibers in the gastrocnemius muscle using the in situ expression of the denervation-specific sodium channel, Nav_1.5, in young adult (YA) and senescent (SEN) rats. To gain insights into the mechanisms driving myofiber atrophy, we also examined the myofiber expression of the two primary ubiquitin ligases necessary for muscle atrophy (MAFbx, MuRF1). MN soma number in lumbar spinal cord declined 27% between YA (638±34 MNs×mm⁻¹) and SEN (469±13 MNs×mm⁻¹). Nav_1.5 positive fibers (1548±70 μm²) were 35% smaller than Nav_1.5 negative fibers (2367±78 μm²; P<0.05) in SEN muscle, whereas Nav_1.5 negative fibers in SEN were only 7% smaller than fibers in YA (2553±33 μm²; P<0.05) where no Nav_1.5 labeling was seen, suggesting denervation is the primary cause of aging myofiber atrophy. Nav_1.5 positive fibers had higher levels of MAFbx and MuRF1 (P<0.05), consistent with involvement of the proteasome proteolytic pathway in the atrophy of denervated muscle fibers in aging muscle. In summary, our study provides the first quantitative assessment of the contribution of denervation to myofiber atrophy in aging muscle, suggesting it explains the majority of the atrophy we observed. This striking result suggests a renewed focus should be placed on denervation in seeking understanding of the causes of and treatments for aging muscle atrophy.

Pathways of change experienced by people aging with disability: a focus group study

PURPOSE

To examine the issues related to aging with disability from the perspective of the person with the disabilities.

METHOD

Twelve community-dwelling adults with spinal cord injury (SCI), post-polio syndrome (PPS) or multiple sclerosis (MS) participated in focus groups where they were asked open-ended questions about changes related to aging with disability, accommodations made and perspectives on the future.

RESULTS

Results of qualitative analysis suggested five major themes related to aging with a disability: (1) Participant identity, including comments about how participants described themselves and their lives with a long-standing disability; (2) Physical pathways including comments about the progression of physical symptoms; (3) Psychosocial pathways, including descriptions of adaptations to disability, the development of emotional well-being and strategies to deal with disability; (4) Changing health care, reflecting improvement noted over time in health care services; and (5) Concerns about the future, including comments reflecting participant uncertainty about the potential course of disability.

CONCLUSIONS

The process of aging with disability was characterised by multiple pathways. Some, including positive psychosocial adjustment and medical advancements, were favourable, while others, including physical decline, were not. The co-existence of high quality of life in the presence of physical decline is consistent with a larger literature in older adults, and future research should focus on identifying aging factors that may contribute to the buffering the psychological impact of physical decline.

Psychosocial factors and adjustment to pain in individuals with postpolio syndrome

OBJECTIVE

The purpose of the current study was to examine the associations among measures of psychosocial factors, pain, and adjustment in persons with postpoliomyelitis syndrome.

DESIGN

A cross-sectional survey design was used. Sixty-three community-dwelling individuals with postpoliomyelitis syndrome returned completed questionnaires (71% response rate) that included measures of pain intensity and interference, psychological functioning, pain catastrophizing, social support, and pain-related beliefs and coping.

RESULTS

After controlling for demographic variables, the group of psychosocial variables accounted for an additional 23% of the variance in pain intensity. These variables explained an additional 35% and 50% of the variance in pain interference and psychological functioning, respectively, after accounting for demographic variables and pain intensity. Social support was associated with both psychological functioning and pain interference, whereas catastrophizing was most closely related to psychological functioning. Individual pain beliefs and coping strategies were variably related to the three criterion measures.

CONCLUSIONS

The overall results of the current study are consistent with a biopsychosocial framework for understanding pain and functioning in individuals with postpoliomyelitis syndrome. Although additional research is needed to clarify the nature of the relationships between individual psychosocial variables and functional indices, the findings suggest the need for a multidisciplinary approach to pain management in individuals with postpoliomyelitis syndrome.

Pain in persons with postpolio syndrome: frequency, intensity, and impact

OBJECTIVE

To describe the frequency, intensity, and impact of pain in persons with postpoliomyelitis syndrome (PPS).

DESIGN

Retrospective, cross-sectional survey.

SETTING

Community-based survey.

PARTICIPANTS

Convenience sample of people with PPS.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Overall intensity and duration of pain, pain sites, pain interference, pain treatments, and relief provided by pain treatments.

RESULTS

A total of 91% (n=57) of the study participants (N=63) reported pain. The most frequently reported pain sites were the shoulders, lower back, legs, and hips. Participants reported pain intensity to be the greatest in the knees, legs, wrists, lower back, and head. Pain interfered most with sleep and with activities requiring a high level of musculoskeletal involvement. Respondents also reported pain problems that were more severe than those of the general population and than those of a sample of people with multiple sclerosis. Many treatments had been tried previously for pain, but continued use of treatments was reported by relatively few participants at the time of the survey.

CONCLUSIONS

The findings indicate that pain is a persistent and common problem in persons with PPS, highlighting the need for effective and accessible pain treatments for this population.