Primary Lateral Sclerosis: Difference between revisions

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<h2> Definition  </h2>
== Definition  ==
<p>Primary Lateral Sclerosis (PLS) is characterized as being a rare, non-hereditary, idiopathic, slow, and progressive degeneration of the upper motor neurons<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Statland, J. M., Barohn, R. J., Dimachkie, M. M., Floeter, M. K., &amp;amp;amp;amp;amp;amp;amp;amp; Mitsumoto, H. (2015). Primary lateral sclerosis. Neurologic Clinics, 33(4), 749-760. doi:10.1016/j.ncl.2015.07.007</span>. PLS lies on a continuum of sporadic motor neuron disorders. This spectrum includes other disorders such as progressive muscular atrophy, which involves only lower motor neurons, as well as amyotrophic lateral sclerosis (ALS), characterized by both upper and lower motor neuron involvement. Many patients diagnosed with PLS continue to have high levels of independence for many years<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Gordon, P. H., Cheng, B., Katz, I. B., Pinto, M., Hays, A. P., Mitsumoto, H., &amp;amp;amp;amp;amp;amp;amp;amp; Rowland, L. P. (2006). The natural history of primary lateral sclerosis. Neurology, 66(5), 647-653. doi: 10.1212/01.wnl.0000200962.94777.71</span>.  
 
</p>
Primary Lateral Sclerosis (PLS) is characterized as being a rare, non-hereditary, idiopathic, slow, and progressive degeneration of the upper motor neurons<ref name="statland et al.">Statland, JM, Barohn, RJ, Dimachkie, MM, Floeter, MK, Mitsumoto, H. Primary lateral sclerosis. Neurologic Clinics 2015;33:749-760.</ref>. PLS lies on a continuum of sporadic motor neuron disorders. This spectrum includes other disorders such as progressive muscular atrophy, which involves only lower motor neurons, as well as amyotrophic lateral sclerosis (ALS), characterized by both upper and lower motor neuron involvement. Many patients diagnosed with PLS continue to have high levels of independence for many years<ref name="gordon et al.">Gordon, PH, Cheng, B, Katz, IB, Pinto, M, Hays, AP, Mitsumoto, H, Rowland, LP. The natural history of primary lateral sclerosis. Neurology 2006;66:647-653.</ref>.  
<h2> Epidemiology  </h2>
 
<p>Approximately 2-5% of adults in neuromuscular clinics will be diagnosed with PLS<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Singer, M. A., Statland, J. M., Wolfe, G. I., &amp;amp;amp;amp;amp;amp; Barohn, R. J. (2007). Primary Lateral Sclerosis. Muscle &amp;amp;amp;amp;amp;amp; Nerve, 35(3), 291-302. doi: 10.1002/mus.20728</span>. The age of onset ranges from a mean age of 45.4-53.7 years, though a juvenile form of PLS has been described as well. Although the difference is not pronounced, there is a slight male predominance over females in being diagnosed with PLS.  
== Epidemiology  ==
</p>
 
<h2> Etiology  </h2>
Approximately 2-5% of adults in neuromuscular clinics will be diagnosed with PLS<ref name="singer et al.">Singer, MA, Statland, JM, Wolfe, GI, Barohn, RJ. Primary Lateral Sclerosis. Muscle and Nerve 2007;35:291-302.</ref>. The age of onset ranges from a mean age of 45.4-53.7 years, though a juvenile form of PLS has been described as well. Although the difference is not pronounced, there is a slight male predominance over females in being diagnosed with PLS.  
<p>The exact cause of adult-onset PLS remains unknown<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Singer, M. A., Statland, J. M., Wolfe, G. I., &amp;amp;amp;amp;amp;amp; Barohn, R. J. (2007). Primary Lateral Sclerosis. Muscle &amp;amp;amp;amp;amp;amp; Nerve, 35(3), 291-302. doi: 10.1002/mus.20728</span>. PLS is a diagnosis of exclusion, meaning that individuals are diagnosed with the condition when their progressive upper motor neuron dysfunctions cannot be explained by any other possible cause.  
 
</p>
== Etiology  ==
<h2> Clinical Presentation  </h2>
 
<h2> Prognosis  </h2>
The exact cause of adult-onset PLS remains unknown<ref name="singer et al." />. PLS is a diagnosis of exclusion, meaning that individuals are diagnosed with the condition when their progressive upper motor neuron dysfunctions cannot be explained by any other possible cause.  
<p>A distinctive clinical feature of PLS is that it has a very slow progression, leading it to be considered to have a more benign prognosis in comparison to ALS<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Singer, M. A., Statland, J. M., Wolfe, G. I., &amp;amp;amp;amp;amp;amp; Barohn, R. J. (2007). Primary Lateral Sclerosis. Muscle &amp;amp;amp;amp;amp;amp; Nerve, 35(3), 291-302. doi: 10.1002/mus.20728</span>. The longevity of individuals with PLS is unclear, but it has been estimated to be 7.9 years or longer. Individuals with PLS and minimal EMG changes appear to have a decreased ability to ambulate independently in comparison to those without EMG changes. Nonetheless, patients may still be able to ambulate without aids after several years of being diagnosed. It is common for patients to be diagnosed with PLS but later diagnosed with ALS instead. Due to their similar course of progression, misdiagnosis can occur. A detailed spectrum of PLS categories have been detailed<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Singer, M. A., Statland, J. M., Wolfe, G. I., &amp;amp;amp;amp;amp;amp; Barohn, R. J. (2007). Primary Lateral Sclerosis. Muscle &amp;amp;amp;amp;amp;amp; Nerve, 35(3), 291-302. doi: 10.1002/mus.20728</span><span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref">Gordon, P. H., Cheng, B., Katz, I. B., Pinto, M., Hays, A. P., Mitsumoto, H., &amp;amp;amp;amp;amp;amp;amp;amp; Rowland, L. P. (2006). The natural history of primary lateral sclerosis. Neurology, 66(5), 647-653. doi: 10.1212/01.wnl.0000200962.94777.71</span>.
 
</p>
== Clinical Presentation  ==
<h2> Interventions  </h2>
 
<h4> Physical Therapy&nbsp; </h4>
== Prognosis  ==
<h4> Medical and Surgical  </h4>
 
<h2> Differential Diagnoses  </h2>
A distinctive clinical feature of PLS is that it has a very slow progression, leading it to be considered to have a more benign prognosis in comparison to ALS<ref name="singer et al." />. The longevity of individuals with PLS is unclear, but it has been estimated to be 7.9 years or longer. Individuals with PLS and minimal EMG changes appear to have a decreased ability to ambulate independently in comparison to those without EMG changes. Nonetheless, patients may still be able to ambulate without aids after several years of being diagnosed. It is common for patients to be diagnosed with PLS but later diagnosed with ALS instead. Due to their similar course of progression, misdiagnosis can occur. A detailed spectrum of PLS categories have been detailed<ref name="singer et al." /><ref name="gordon et al." />.  
<p>(Statland et al, 2015); (Kuipers-Upmeijer et al, 2001); (Strong &amp; Gordon, 2005)<br /> <br />As PLS is an upper motor neuron issue, there are several potential differential diagnosis. The 2 most likely upper motor neuron diseases that is associated with PLS are …
 
</p>
== Interventions  ==
<ul><li>Amyotrophic lateral sclerosis (Statland et al, 2015); (Strong &amp; Gordon, 2005)
 
</li></ul>
==== Physical Therapy&nbsp; ====
<p>&nbsp; &nbsp; &nbsp; &nbsp; - ALS presents with lower and/or upper motor deficits and has fast(er) progression; PLS is slower progression and typically only affects &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;upper motor neurons.<br />&nbsp; &nbsp; &nbsp; &nbsp; - ALS is more commonly associated with stiffness then PLS (47% vs 4%)<br />&nbsp; &nbsp; &nbsp; &nbsp; - Both ALS and PLS can be assoicated with cognitive issues but is not present in its ‘uncomplicated’ forms (Strong &amp; Gordon, 2005).<br />
 
</p>
==== Medical and Surgical  ====
<ul><li>Hereditary spastic paraplegias (Strong &amp; Gordon, 2005)
 
</li></ul>
== Differential Diagnoses  ==
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;- HSP has spasticity of the lower limbs; PLS is associated with spasticity as well and slight weakness but spasticity can affect &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;speech (spastic dysarthria)<br />&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;- Complicated cases of HSP can result in dementia &amp; mental retardation which may mimic cognitive issues possibly present in &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;complicated cases of PLS.
 
</p><p>Other potential, but less specific, differential considerations include (Statland et al, 2015)…
(Statland et al, 2015); (Kuipers-Upmeijer et al, 2001); (Strong &amp; Gordon, 2005)<br> <br>As PLS is an upper motor neuron issue, there are several potential differential diagnosis. The 2 most likely upper motor neuron diseases that is associated with PLS are …
</p>
 
<ul><li>Structural lesions, especially related to the spine (eg. cervical spondylmyelopathy)
*Amyotrophic lateral sclerosis (Statland et al, 2015); (Strong &amp; Gordon, 2005)
</li><li>Infection (eg. HIV, syphilis)
 
</li><li>Demyelinating disease (eg. mutliple sclerosis)
&nbsp; &nbsp; &nbsp; &nbsp; - ALS presents with lower and/or upper motor deficits and has fast(er) progression; PLS is slower progression and typically only affects &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;upper motor neurons.<br>&nbsp; &nbsp; &nbsp; &nbsp; - ALS is more commonly associated with stiffness then PLS (47% vs 4%)<br>&nbsp; &nbsp; &nbsp; &nbsp; - Both ALS and PLS can be assoicated with cognitive issues but is not present in its ‘uncomplicated’ forms (Strong &amp; Gordon, 2005).<br>
</li><li>Metabolic / toxic (eg. vitamin E deficiency)
 
</li><li>Neurodegenerative (eg. Parkinsons and parkinson's-plus syndromes)
*Hereditary spastic paraplegias (Strong &amp; Gordon, 2005)
</li></ul>
 
<p><br />Special care must be taken when diagnosing as PLS can be misdiagnosed as the above examples, and many more (Kuipers-Upmeijer et al, 2001).<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;- HSP has spasticity of the lower limbs; PLS is associated with spasticity as well and slight weakness but spasticity can affect &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;speech (spastic dysarthria)<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;- Complicated cases of HSP can result in dementia &amp; mental retardation which may mimic cognitive issues possibly present in &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;complicated cases of PLS.
</p>
 
<h2> References </h2>
Other potential, but less specific, differential considerations include (Statland et al, 2015)
<p><span class="fck_mw_references" _fck_mw_customtag="true" _fck_mw_tagname="references" />
 
</p>
*Structural lesions, especially related to the spine (eg. cervical spondylmyelopathy)
*Infection (eg. HIV, syphilis)  
*Demyelinating disease (eg. mutliple sclerosis)
*Metabolic / toxic (eg. vitamin E deficiency)
*Neurodegenerative (eg. Parkinsons and parkinson's-plus syndromes)
 
<br>Special care must be taken when diagnosing as PLS can be misdiagnosed as the above examples, and many more (Kuipers-Upmeijer et al, 2001).<br>
 
== References  ==
 
<references />

Revision as of 19:19, 2 May 2017

Definition[edit | edit source]

Primary Lateral Sclerosis (PLS) is characterized as being a rare, non-hereditary, idiopathic, slow, and progressive degeneration of the upper motor neurons[1]. PLS lies on a continuum of sporadic motor neuron disorders. This spectrum includes other disorders such as progressive muscular atrophy, which involves only lower motor neurons, as well as amyotrophic lateral sclerosis (ALS), characterized by both upper and lower motor neuron involvement. Many patients diagnosed with PLS continue to have high levels of independence for many years[2].

Epidemiology[edit | edit source]

Approximately 2-5% of adults in neuromuscular clinics will be diagnosed with PLS[3]. The age of onset ranges from a mean age of 45.4-53.7 years, though a juvenile form of PLS has been described as well. Although the difference is not pronounced, there is a slight male predominance over females in being diagnosed with PLS.

Etiology[edit | edit source]

The exact cause of adult-onset PLS remains unknown[3]. PLS is a diagnosis of exclusion, meaning that individuals are diagnosed with the condition when their progressive upper motor neuron dysfunctions cannot be explained by any other possible cause.

Clinical Presentation[edit | edit source]

Prognosis[edit | edit source]

A distinctive clinical feature of PLS is that it has a very slow progression, leading it to be considered to have a more benign prognosis in comparison to ALS[3]. The longevity of individuals with PLS is unclear, but it has been estimated to be 7.9 years or longer. Individuals with PLS and minimal EMG changes appear to have a decreased ability to ambulate independently in comparison to those without EMG changes. Nonetheless, patients may still be able to ambulate without aids after several years of being diagnosed. It is common for patients to be diagnosed with PLS but later diagnosed with ALS instead. Due to their similar course of progression, misdiagnosis can occur. A detailed spectrum of PLS categories have been detailed[3][2].

Interventions[edit | edit source]

Physical Therapy [edit | edit source]

Medical and Surgical[edit | edit source]

Differential Diagnoses[edit | edit source]

(Statland et al, 2015); (Kuipers-Upmeijer et al, 2001); (Strong & Gordon, 2005)

As PLS is an upper motor neuron issue, there are several potential differential diagnosis. The 2 most likely upper motor neuron diseases that is associated with PLS are …

  • Amyotrophic lateral sclerosis (Statland et al, 2015); (Strong & Gordon, 2005)

        - ALS presents with lower and/or upper motor deficits and has fast(er) progression; PLS is slower progression and typically only affects                upper motor neurons.
        - ALS is more commonly associated with stiffness then PLS (47% vs 4%)
        - Both ALS and PLS can be assoicated with cognitive issues but is not present in its ‘uncomplicated’ forms (Strong & Gordon, 2005).

  • Hereditary spastic paraplegias (Strong & Gordon, 2005)

         - HSP has spasticity of the lower limbs; PLS is associated with spasticity as well and slight weakness but spasticity can affect                              speech (spastic dysarthria)
         - Complicated cases of HSP can result in dementia & mental retardation which may mimic cognitive issues possibly present in                              complicated cases of PLS.

Other potential, but less specific, differential considerations include (Statland et al, 2015)…

  • Structural lesions, especially related to the spine (eg. cervical spondylmyelopathy)
  • Infection (eg. HIV, syphilis)
  • Demyelinating disease (eg. mutliple sclerosis)
  • Metabolic / toxic (eg. vitamin E deficiency)
  • Neurodegenerative (eg. Parkinsons and parkinson's-plus syndromes)


Special care must be taken when diagnosing as PLS can be misdiagnosed as the above examples, and many more (Kuipers-Upmeijer et al, 2001).

References[edit | edit source]

  1. Statland, JM, Barohn, RJ, Dimachkie, MM, Floeter, MK, Mitsumoto, H. Primary lateral sclerosis. Neurologic Clinics 2015;33:749-760.
  2. 2.0 2.1 Gordon, PH, Cheng, B, Katz, IB, Pinto, M, Hays, AP, Mitsumoto, H, Rowland, LP. The natural history of primary lateral sclerosis. Neurology 2006;66:647-653.
  3. 3.0 3.1 3.2 3.3 Singer, MA, Statland, JM, Wolfe, GI, Barohn, RJ. Primary Lateral Sclerosis. Muscle and Nerve 2007;35:291-302.