Poliomyelitis/Post-polio syndrome Flashcards
Post-polio syndrome:
1. New muscle weakness as a late sequela of poliomyelitis was initially recognized by Charcot and others in ____.
2. Between 1875 and 1975, about ____ cases were reported in the world’s literature.
3. From ______, a large “epidemic” of several thousand
cases occurred
- 1875
- 200
- 1975-95
4 names of the syndrome of new muscle weakness that occurs as late sequala of poliomyelitis
1985 Halstead – Post polio syndrome (PPS)
1995 Dalakas – Post polio muscular atrophy (PPMA)
1996 Berg – Post Polio Muscular dysfunction (PPMD)
1988 Howard – Post-polio functional deterioration (PPFD)
8 features of post-polio syndrome
Fatigue New weakness with muscle atrophy Muscular/joint pain Difficulty sleeping Difficulty breathing Difficulty swallowing Poor cold tolerance Unable to perform normal daily activities of living
Name the most common late manifestations of poliomyelitis in patients referred to post-polio clinics (in order of prevalence)
- Fatigue - 89%
- Weakenss (previously affected muscles 69%, unaffected muscles 50%) – 87% - 90%
- Joint pain - 71%
- Muscle pain 71%
- Atrophy - 28%
- Cold intolerane 29%
- Dysphagia 27%
Diagnostic criteria of post-polio syndrome according to consensus of post-polio task force
- A prior episode of paralytic poliomyelitis with residual motor neuron loss (which can be confirmed through a typical patient history, a neurologic examination, and, if needed, an electrodiagnostic exam).
- A period of neurologic recovery followed by an interval (usually 15 years or more) of neurologic and functional stability.
- A gradual or abrupt onset of new weakness or abnormal muscle fatigue (decreased endurance), muscle atrophy, or generalized fatigue.
- Exclusion of medical, orthopedic, and neurologic conditions that may be causing the symptoms mentioned in 3.
Describe peripheral disintegration model of PPS
1. Virus affects:
2. which causes loss of innervation due to:
3. recovery occurs when
4 eventually
- grey matter killing anterior horn cells
- infected neurons
- there is axonal sprouting
4 these are neuropathic as well (“reduced pool of available neurons”) - there is no recurrence of the virus.
Hypotheses of post-polio syndrome (3)
- Persistence of genetic viral materials able to stimulate and deregulate the inflammatory and immune system response locally, in the central or peripheral nervous system
the old hypothesis of an inactive and persistent virus is totally excluded - Imbalance between degenerative and regenerative physiological processes of the enlarged motor units (probably related to an alteration of the regulation mechanisms)
3 Structural and functional abnormalities of the muscle fibers and/or abnormal sensorimotor integration (primary or secondary).
Pathophysiology of post-polio syndrome:
Aging of the neuromuscular system under chronic denervation
3 factors
1 Alteration of the structure of muscular fibers
2 The muscular fibers of the partially denervated and solicited muscles modify their structure:
3 changes were described in the phenotypes of contractile cells associated to the changes in contractile properties of type 1 fibers,
Pathophysiology of PPS:
Denervation leads to what metabolic changes?
the decrease in production capacity of type 1 muscular fibers obtained from patients with poliomyelitis sequelae was reported and deemed responsible for a greater fatigue compared to healthy muscular fibers;
Contributing factors to the pathophysiology of PPS: (5)
Neurological complications Orthopedic complications Medical complications Hypoventilation Psychological complications
3 neurological complications of Post-polio syndrome
1 Entrapment syndromes of the upper limbs
triggered by the use of canes, wheelchair propulsion or transfers.
incidence was estimated at 80% (Tsai et al.)
compression of the median nerve of the carpal tunnel 62%
2 Radiculopathy, sciatica or crural neuralgia
3 Spinal Stenosis
3 orthopedic complications of post-polio syndrome
Scoliosis or kyphosis
Tendon diseases
Most common: shoulder (rotator cuff) or elbow (epicondylitis)
Secondary arthritis
affects mostly the lower limbs: knee and hip arthritis
also shoulder, acromioclavicular, elbow
prevalence 63% (Kidd et al)
arthritic aggravation of knee recurvatum is quite common
Foot arthritis: tibiotarsal, talonavicular or tarsometatarsal joints
Discuss the degeneration of muscle fibers and motor units over time with regard to pathophysiology of PPS
The reinnervation mechanism observed at the beginning of the affection does not linger over time and reinnervated motor fibers become unstable on the long term with a progressive loss of their axonal nerve terminals, leading to a size decrease of the giant motor units.
Years of intense use of these enlarged motor units adds stress to the neuronal cell body, which then may not be able to maintain the metabolic demands of all the new sprouts, resulting in the slow deterioration of motor units
deterioration of the denervation-reinnervation mechanism at the level of newly formed neuromuscular junctions. This phenomenon may be aggravated by an intense muscular activation on the long term
3 medical complications of post-polio sydrome
*** in what percentage of patients?
- Weight Gain
(28.4%) were overweight (BMI, >25kg/m2). - Dyslipidemia
61.3% polio survivors
15.3% for non-Hispanic white men, 10.9%for non-Hispanic black men and 16.8% for Mexican-American men - Hypoventilation - prevalence is higher than 50% in polio survivors
In 86% of cases, it is obstructive sleep apnea
Flu vaccines are highly recommended
Respiratory physical therapy can be indicated
Others: tracheostomy, BiPAP, O2
PPS can have a similar decline when compared to what? why?
Similar delayed progressive decline seen in survivors of other conditions (myelopathy) that injured anterior horn cells (metabolic overload of enlarged or fragile motor units
PPS is not juse ______ of the motor units:
Taiwanese polio survivors are 10-20 years younger than Western patients at onset of post-polio symptoms (Chang et al., Spinal Cord 39:526, 2001)
4 factors of post-polio muscle pain
Occurs in muscles affected by polio
Deep aching pain, with cramps and fasciculations
Occurs in the evening or at night
Exacerbated by physical activity, cold and stress
4 treatments of post-polio muscle pain
Rest
Heat
Stretching
Medication (amitriptyline, lamotrigine)
*** lamotrigine is the only possible medication that might treat post-polio symptoms but only because it did not fail during trials, not because it was shown to be benficial
When comparing exacerbating factors of post-polio pain, they were more similar to ____
persons with no post polio muscle pain
While not the hallmark of Post polio MA, _____ is the most common symptom
Fatigue: Klein, et al., studied 120 patients and reported decreasing strength, at a rate higher than normal aging and in upper extremities and flexors of the leg (repetitive stepping muscles, not weight-bearing)
Name the four types of fatigue in Post polio muscle atrophy
central fatigue • emotional fatigue • fatigue from deconditioning • augmented peripheral fatigue • enlarged muscle fibers that activate more slowly, contract less well, or recover abnormall
Fatigue in Post polio muscle atrophy: Occurs in \_\_\_\_ % Alteration of function of: \_\_\_\_\_ fatigability: Overlapping \_\_\_\_\_\_ factors
59 to 89%
Alteration of the function of the NMJs developed during the recovery process after the initial polio infection
Central fatigability (decreased attention and concentration and memory loss) due to involvement of various brain structures including the reticular activating system
Overlapping psychological factors
What is the fatigue severity scale?
Use in?
Subjective fatigue and is composed of 9 statements that are rated on a scale from 1 (strong disagreement) to 7 (strong agreement).
Followed for five years
Post polio syndrome
OF the following treatments of post-polio syndrome, which were beneficial?
- Muscle strengthening:
- Rehab (hot/cold climate)
- Static magnetic fields
- Aerobics and flexibility exercises
- Hydrokinesitherapy
- maybe
- No/No
- Maybe
- Maybe
- maybe
