Primary Lateral Sclerosis: Difference between revisions

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== Epidemiology  ==
== Epidemiology  ==


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.  
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.  


== Etiology  ==
== Etiology  ==
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== Prognosis  ==
== Prognosis  ==


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." />.  
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="gordon et al." /><ref name="singer et al." /><span style="font-size: 13.28px;">.</span>


== Interventions  ==
== Interventions  ==
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== Differential Diagnoses  ==
== Differential Diagnoses  ==


(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
(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:


*Amyotrophic lateral sclerosis (Statland et al, 2015); (Strong &amp; Gordon, 2005)
1. Amyotrophic lateral sclerosis<ref name="statland et al." /> <ref name="strong and gordon">Strong, MJ, Gordon, PH. Primary lateral sclerosis, hereditary spastic paraplegia and amyotrophic lateral sclerosis: Discrete entities or spectrum? Amyotrophic Lateral Sclerosis 2005; 6:8-16.</ref>


&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>  
*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<ref name="strong and gordon" />


*Hereditary spastic paraplegias (Strong &amp; Gordon, 2005)


&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.


Other potential, but less specific, differential considerations include (Statland et al, 2015)…
2. Hereditary spastic paraplegias<ref name="strong and gordon" />
 
*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 &amp; mental retardation which may mimic cognitive issues possibly present in complicated cases of PLS.
 
 
 
Other potential, but less specific, differential considerations include:&nbsp;<ref name="statland et al." />


*Structural lesions, especially related to the spine (eg. cervical spondylmyelopathy)  
*Structural lesions, especially related to the spine (eg. cervical spondylmyelopathy)  
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*Neurodegenerative (eg. Parkinsons and parkinson's-plus syndromes)
*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>  
<br>Special care must be taken when diagnosing as PLS can be misdiagnosed as the above examples, and many more<ref name="kuipers">Kuipers-Upmeijer, J, de Jager, A, Hew, J, Snoek, J, van Weerden, T. Primary lateral sclerosis: Clinical, neurophysiological, and magnetic resonance findings. Journal of Neurology Neurosurgery and Psychiatry 2001; 71:615-620.</ref>.<br>  


== References  ==
== References  ==


<references />
<references />

Revision as of 20:07, 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[2][3].

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:

1. Amyotrophic lateral sclerosis[1] [4]

  • 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[4]


2. Hereditary spastic paraplegias[4]

  • 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: [1]

  • 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[5].

References[edit | edit source]

  1. 1.0 1.1 1.2 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.
  4. 4.0 4.1 4.2 Strong, MJ, Gordon, PH. Primary lateral sclerosis, hereditary spastic paraplegia and amyotrophic lateral sclerosis: Discrete entities or spectrum? Amyotrophic Lateral Sclerosis 2005; 6:8-16.
  5. Kuipers-Upmeijer, J, de Jager, A, Hew, J, Snoek, J, van Weerden, T. Primary lateral sclerosis: Clinical, neurophysiological, and magnetic resonance findings. Journal of Neurology Neurosurgery and Psychiatry 2001; 71:615-620.