Poliomyelitis
Updates to Article Attributes
Poliomyelitis, more commonly known as just polio, is a once common but now rare disease resulting from infection by the poliovirus. Most infected individuals develop no or non-serious symptoms as a result of the infection, but ~1% will develop life-altering disability (paralysis) due to destruction of motor neurons.
Epidemiology
Although once a common disease worldwide, polio is now virtually non-existent in the Western hemisphere due to immunisation. Only 1,579 cases were confirmed in 2009 worldwide 2. The virus is most commonly spread via the faecal-oral route. However, oral-oral transmission is possible.
Clinical presentation
Two forms of poliomyelitis can occur after infection with poliovirus 5:
-
non-paralytic poliomyelitis
- form of aseptic meningitis
- flu-like prodrome followed by muscular stiffness +/- paresthesia
-
paralytic poliomyelitis
- biphasic illness with symptoms of non-septic meningitis, followed by a few days of being symptoms free then paralysis develops
- lower limbs more often affected than upper limbs
Radiographic features
Conventional radiograph and CT
With acute infection, no radiographic features are typically evident. Chronically, findings are characterised by atrophy of involved areas, including of bone and muscle, which may be similar to other neuromuscular disorders. The extent of fatty muscle atrophy and/or bone atrophy may be striking.
MRI
Neuroimaging may reveal ALS-like abnormalities in the affected areas of the ventral motor tracts in the spine and/or motor cortex, which are characteristically hyperintense on T2WI 3,4.
Extensive fatty muscle atrophy may be seen in affected areas of the musculoskeletal system, which may be unilateral or bilateral.
Treatment and prognosis
In the modern Western world poliomyelitis is prevented by vaccination. As no cure for poliomyelitis itself is available, treatment is supportive and aimed at preventing complications and a quick recovery. Antibiotics are given to prevent infection of weakened muscles. Often a long period of rehabilitation is necessary to regain full function of affected body parts 6.
Prognosis depends on the extent of motor neuron destruction by the time treatment is started and varies from complete recovery to severely debilitating paralysis 7.
History and etymology
"Poliomyelitis" derives from the Greek πολιός ("grey") and μνελός ("marrow"), indicating how the disease affects the spinal cord grey matter. It was first described by J Heine in 1840 8.
Differential diagnosis
-</ul><h4>Radiographic features</h4><h5>Conventional radiograph and CT</h5><p>With acute infection, no radiographic features are typically evident. Chronically, findings are characterised by atrophy of involved areas, including of bone and muscle, which may be similar to other <a href="/articles/neuromuscualr-disorders">neuromuscular disorders</a>. The extent of fatty muscle atrophy and/or bone atrophy may be striking. </p><h5>MRI</h5><p>Neuroimaging may reveal <a href="/articles/amyotrophic-lateral-sclerosis-3">ALS</a>-like abnormalities in the affected areas of the ventral motor tracts in the spine and/or motor cortex, which are characteristically hyperintense on T2WI <sup>3,4</sup>. </p><p>Extensive fatty muscle atrophy may be seen in affected areas of the musculoskeletal system, which may be unilateral or bilateral. </p><h4>Treatment and prognosis</h4><p>In the modern Western world poliomyelitis is prevented by vaccination. As no cure for poliomyelitis itself is available, treatment is supportive and aimed at preventing complications and a quick recovery. Antibiotics are given to prevent infection of weakened muscles. Often a long period of rehabilitation is necessary to regain full function of affected body parts <sup>6</sup>.</p><p>Prognosis depends on the extent of motor neuron destruction by the time treatment is started and varies from complete recovery to severely debilitating paralysis <sup>7</sup>.</p><h4>Differential diagnosis</h4><ul>- +</ul><h4>Radiographic features</h4><h5>Conventional radiograph and CT</h5><p>With acute infection, no radiographic features are typically evident. Chronically, findings are characterised by atrophy of involved areas, including of bone and muscle, which may be similar to other <a href="/articles/neuromuscualr-disorders">neuromuscular disorders</a>. The extent of fatty muscle atrophy and/or bone atrophy may be striking. </p><h5>MRI</h5><p>Neuroimaging may reveal <a href="/articles/amyotrophic-lateral-sclerosis-3">ALS</a>-like abnormalities in the affected areas of the ventral motor tracts in the spine and/or motor cortex, which are characteristically hyperintense on T2WI <sup>3,4</sup>. </p><p>Extensive fatty muscle atrophy may be seen in affected areas of the musculoskeletal system, which may be unilateral or bilateral. </p><h4>Treatment and prognosis</h4><p>In the modern Western world poliomyelitis is prevented by vaccination. As no cure for poliomyelitis itself is available, treatment is supportive and aimed at preventing complications and a quick recovery. Antibiotics are given to prevent infection of weakened muscles. Often a long period of rehabilitation is necessary to regain full function of affected body parts <sup>6</sup>.</p><p>Prognosis depends on the extent of motor neuron destruction by the time treatment is started and varies from complete recovery to severely debilitating paralysis <sup>7</sup>.</p><h4>History and etymology</h4><p>"Poliomyelitis" derives from the Greek πολιός ("grey") and μνελός ("marrow"), indicating how the disease affects the spinal cord grey matter. It was first described by <strong>J Heine</strong> in 1840 <sup>8</sup>.</p><h4>Differential diagnosis</h4><ul>
References changed:
- 8. Skinner HA. Origin of Medical Terms. Hafner Publishing Co Ltd. ISBN:0028523903. <a href="http://books.google.com/books?vid=ISBN0028523903">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0028523903">Find it at Amazon</a><span class="auto"></span>
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