To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

Progressive muscular atrophy

From Wikipedia, the free encyclopedia

Progressive muscular atrophy
Other namesDuchenne–Aran muscular atrophy, others
SpecialtyNeurology

Progressive muscular atrophy (PMA), also called Duchenne–Aran disease and Duchenne–Aran muscular atrophy, is a disorder characterised by the degeneration of lower motor neurons, resulting in generalised, progressive loss of muscle function.

PMA is classified among motor neuron diseases (MND) where it is thought to account for around 4% of all MND cases.[1]

PMA affects only the lower motor neurons, in contrast to amyotrophic lateral sclerosis (ALS), the most common MND, which affects both the upper and lower motor neurons, or primary lateral sclerosis, another MND, which affects only the upper motor neurons. The distinction is important because PMA is associated with a better prognosis than ALS.

YouTube Encyclopedic

  • 1/5
    Views:
    5 905
    8 276
    187 096
    17 405
    136 959
  • Spinal Muscular Atrophy Disease Progression
  • A Personal Story of the Progression of Spinal Muscular Atrophy in a Toddler
  • Muscular Dystrophy - Duchenne, Becker and Mytonic
  • Duchenne Muscular Dystrophy
  • Duchenne Muscular Dystrophy: Ryan's Story

Transcription

Spinal muscular atrophy is viewed by us as a progressive neurodegenerative disease, but the measurement of progression varies depending upon the severity of the clinical phenotype. So that in the type one baby who becomes usually affected in early infancy, often around two or three months of age or such, we see that they drop off in their capacity to carry out critical functions like being strong enough to breathe for example. And so the progression under those circumstances is quite clear and obviously quite grave as such. And it puts the children at high risk of dying often within the first two years of life. In the type two children and the type three children, the progression is less obvious, more subtle over time. And we've debated repeatedly as to whether the disease is truly progressive as it relates to the loss of these motoneurons in the spinal cord or whether the children are not gaining sufficient strength as they get older to maintain their functions or to achieve new functions. But it's very clear from all the work that's been done by us and by others that the functional deterioration is evident in all three types of the disease. Children with spinal muscular atrophy are at risk for a number of complications and of course the more severe their clinical phenotype, the more severe and more likely are the complications. In the type one babies as we have discussed previously, respiratory failure is a very serious problem and you have to understand that breathing is dependent on your strength. So you have to lift your ribcage, drop your diaphragm down in order for the air to enter into the thoracic cage, and then it has to be expressed afterwards as such. So breathing is such a vital part of the motor functioning and if there's significant weakness, then all these children are a great risk for respiratory failure. They must breathe adequately when they're healthy but if they have an inoccurrent illness or the flu or pneumonia that can be extremely challenging and truly life threatening as such. The other major complication is stabilizing the musculoskeletal system. So again, strength is important to maintain proper alignment of our arms and legs and our torso, spinal column, and so forth. So one of the big complications that these children have is a curvature of the spine or scoliosis and almost every one of these patients are at risk for developing significant scoliosis. As long as they remained ambulatory, the likelihood of developing serious scoliosis is much less, but when they lose the ability to ambulate or fail ever to develop the ability to ambulate, then they are at very great risk, almost one hundred percent likelihood that they'll develop curvature of the spine. As that progresses, usually we have to consider surgical intervention in order to stabilize it or to correct the curvature of the spine.

Signs and symptoms

As a result of lower motor neuron degeneration, the symptoms of PMA include:[citation needed]

Some patients have symptoms restricted only to the arms or legs (or in some cases just one of either). These cases are referred to as flail limb (either flail arm or flail leg) and are associated with a better prognosis.[1]

Diagnosis

PMA is a diagnosis of exclusion, there is no specific test which can conclusively establish whether a patient has the condition. Instead, a number of other possibilities have to be ruled out, such as multifocal motor neuropathy or spinal muscular atrophy. Tests used in the diagnostic process include MRI, clinical examination, and EMG. EMG tests in patients who do have PMA usually show denervation (neuron death) in most affected body parts, and in some unaffected parts too.[2]

It typically takes longer to be diagnosed with PMA than ALS, an average of 20 months for PMA vs 15 months in ALS.[citation needed]

Differential diagnosis

In contrast to amyotrophic lateral sclerosis or primary lateral sclerosis, PMA is distinguished by the absence of:[citation needed]

The importance of correctly recognizing progressive muscular atrophy as opposed to ALS is important for several reasons.

  • The prognosis is a little better. A recent study found the 5-year survival rate in PMA to be 33% (vs 20% in ALS) and the 10-year survival rate to be 12% (vs 6% in ALS).[1]
  • Patients with PMA do not have the cognitive change identified in certain groups of patients with MND.[3]
  • Because PMA patients do not have UMN signs, they usually do not meet the World Federation of Neurology El Escorial Research Criteria for "Definite" or "Probable" ALS and so are ineligible to participate in the majority of clinical trials conducted in ALS.[1]
  • Because of its rarity (even compared to ALS) and confusion about the condition, some insurance policies or local healthcare policies may not recognize PMA as being the life-changing illness that it is. In cases where being classified as being PMA rather than ALS is likely to restrict access to services, it may be preferable to be diagnosed as "slowly progressive ALS" or "lower motor neuron predominant" ALS.

An initial diagnosis of PMA could turn out to be slowly progressive ALS many years later, sometimes even decades after the initial diagnosis. The occurrence of upper motor neuron symptoms such as brisk reflexes, spasticity, or a Babinski sign would indicate a progression to ALS; the correct diagnosis is also occasionally made on autopsy.[4][5]

Prognosis

The 5-year survival rate has been estimated at 33% and the 10-year survival rate at 12%.[1]

History

Despite being rarer than ALS, PMA was described earlier, when in 1850 French neurologist François Aran described 11 cases which he termed atrophie musculaire progressive. Contemporary neurologist Guillaume-Benjamin-Amand Duchenne de Boulogne English: /dˈʃɛn/ also claimed to have described the condition 1 year earlier, although the written report was never found.[6] The condition has been called progressive muscular atrophy (PMA),[7] spinal muscular atrophy (SMA),[7] Aran–Duchenne disease,[6][7] Duchenne–Aran disease,[6] Aran–Duchenne muscular atrophy,[7] and Duchenne–Aran muscular atrophy. The name "spinal muscular atrophy" is ambiguous as it refers to any of various spinal muscular atrophies, including the autosomal recessive spinal muscular atrophy caused by a genetic defect in the SMN1 gene.[citation needed]

Disease or syndrome

Since its initial description in 1850, there has been debate in the scientific literature over whether PMA is a distinct disease with its own characteristics, or if lies somewhere on a spectrum with ALS, PLS, and PBP. Jean-Martin Charcot, who first described ALS in 1870, felt that PMA was a separate condition, with degeneration of the lower motor neurons the most important lesion, whereas in ALS it was the upper motor neuron degeneration that was primary, with lower motor neuron degeneration being secondary. Such views still exist in archaic terms for PMA such as "Primary progressive spinal muscular atrophy". Throughout the course of the late 19th century, other conditions were discovered which had previously been thought to be PMA, such as pseudo-hypertrophic paralysis, hereditary muscular atrophy, progressive myopathy, progressive muscular dystrophy, peripheral neuritis, and syringomyelia.[6]

The neurologists Joseph Jules Dejerine and William Richard Gowers were among those who felt that PMA was part of a spectrum of motor neuron disease which included ALS, PMA, and PBP, in part because it was almost impossible to distinguish the conditions at autopsy. Other researchers have suggested that PMA is just ALS in an earlier stage of progression, because although the upper motor neurons appear unaffected on clinical examination there are in fact detectable pathological signs of upper motor neuron damage on autopsy.[6]

Also, no gene has been linked specifically to PMA, and the disorder does not appear in the OMIM database.[citation needed]

In favour of considering PMA a separate disease, some patients with PMA live for decades after diagnosis, which would be unusual in typical ALS.[6]

To this day, terminology around these diseases remains confusing because in the United Kingdom motor neurone disease refers to both ALS specifically and to the spectrum of ALS, PMA, PLS, and PBP. In the United States the most common terms are ALS (both specifically for ALS and as a blanket term) or Lou Gehrig's disease.[citation needed]

Notable cases

References

  1. ^ a b c d e Wijesekera LC, Mathers S, Talman P, Galtrey C, Parkinson MH, Ganesalingam J, Willey E, Ampong MA, Ellis CM, Shaw CE, Al-Chalabi A, Leigh PN (Mar 2009). "Natural history and clinical features of the flail arm and flail leg ALS variants". Neurology. 72 (12): 1087–1094. doi:10.1212/01.wnl.0000345041.83406.a2. PMC 2821838. PMID 19307543.
  2. ^ Visser J, de Visser M, Van den Berg-Vos RM, Van den Berg LH, Wokke JH, de Jong JM, Franssen H (May 2008). "Interpretation of electrodiagnostic findings in sporadic progressive muscular atrophy". J. Neurol. 255 (6): 903–909. doi:10.1007/s00415-008-0813-y. PMID 18484238. S2CID 189864430.
  3. ^ Wicks P, Abrahams S, Leigh PN, Williams T, Goldstein LH (Nov 2006). "Absence of cognitive, behavioral, or emotional dysfunction in progressive muscular atrophy". Neurology. 67 (9): 1718–1719. doi:10.1212/01.wnl.0000242726.36625.f3. PMID 17101922. S2CID 34610667.
  4. ^ Tsuchiya K, Sano M, Shiotsu H, Akiyama H, Watabiki S, Taki K, Kondo H, Nakano I, Ikeda K (Sep 2004). "Sporadic amyotrophic lateral sclerosis of long duration mimicking spinal progressive muscular atrophy exists: additional autopsy case with a clinical course of 19 years". Neuropathology. 24 (3): 228–235. doi:10.1111/j.1440-1789.2004.00546.x. PMID 15484701. S2CID 41349226.
  5. ^ Ince PG, Evans J, Knopp M, Forster G, Hamdalla HH, Wharton SB, Shaw PJ (Apr 2003). "Corticospinal tract degeneration in the progressive muscular atrophy variant of ALS". Neurology. 60 (8): 1252–1258. doi:10.1212/01.wnl.0000058901.75728.4e. PMID 12707426. S2CID 39178055.
  6. ^ a b c d e f Visser J, de Jong JM, de Visser M (Feb 2008). "The history of progressive muscular atrophy: Syndrome or disease?". Neurology. 70 (9): 723–727. doi:10.1212/01.wnl.0000302187.20239.93. PMID 18299524. S2CID 22629725.
  7. ^ a b c d Elsevier, Dorland's Illustrated Medical Dictionary, Elsevier.

External links

This page was last edited on 17 September 2022, at 21:13
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.