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Disability Benefits for Primary Lateral Sclerosis

LTD / ERISA Disability Lawyers OC, Riverside & San Bernardino

Primary Lateral Sclerosis

What is Primary Lateral Sclerosis?

Primary Lateral Sclerosis (PLS) is a rare neuromuscular disorder of unknown etiology that causes slowly progressive muscle weakness, usually beginning in the lower extremities and then gradually spreading to the upper extremities, the face, trunk, and finally the muscles that control speech, swallowing, and chewing. It is a motor neuron disease, with similarities to amyotrophic lateral sclerosis (ALS), but usually not as severe.


Symptoms include muscle weakness, muscle stiffness and spasticity, clumsiness, slowing of movement, and problems with balance and speech. Although women are also afflicted with PLS, men develop it more frequently, usually in their 40's and 60's. Progressive lower-extremity stiffness and pain may be caused by muscle spasticity.

While there is no known cure or even an effective treatment, measures such as muscle relaxants may reduce spasticity. Physical therapy and occupational therapy may help patients stay mobile. Braces, speech synthesizers, speech therapy, and wheelchairs are helpful as the disease progresses. [Ref:]

Unlike ALS, the prognosis in PLS is less grim, even though PLS is a progressive disorder. Patients diagnosed with PLS may live for decades, but with gradually worsening disability.


In a study published in the Archives of Neurology, “Differentiation Between Primary Lateral Sclerosis and Amyotrophic Lateral Sclerosis,” 2007;64(2):232-236, by Tartaglia MC, et al, the authors noted that muscular stiffness and spasticity was the only symptom that was significantly different between patients with PLS (47%) and patients with ALS (4%) when symptoms first started. Muscle atrophy and limb wasting was not commonly seen in PLS (2%), but it was present virtually in all patients with ALS (100%).  The mortality rate was significantly lower in patients with PLS (33%) than in patients with ALS (89%).

PLS and ALS are similar, but PLS is a less aggressive in most patients.


PLS is diagnosed typically by a neurologist. Electromyography and nerve conduction studies may be helpful in confirming the diagnosis. Genetic studies have focused on mutations in the ALS2 gene, which is responsible for synthesizing a protein called alsin, found in motor neuron cells. However, exactly how this all works is not known.

Disability Related to PLS

Progressive muscle atrophy and weakness may impair your exertional capability to the point that you are unable to perform the essentially duties of your job or any other occupation. Muscle spasticity can cause severe pain in the upper and lower extremities and may significantly impair even sitting.

Your eligibility for long-term disability (LTD) benefits under SSDI or ERISA will depend on the extent of your symptoms as well as the documentation in your medical records of your diagnosis, symptoms, and functional capability.  

If your medical records confirm that you are unable to sit for more than 6 hours out of an 8-hour workday, walk/stand for more than 2 hours, and lift/carry less than 10 pounds, then your functional capacity is “less than sedentary” and your chances of obtaining a LTD award should be good.

At Law Med, we understand these disorders and can work with your doctor(s) to help you achieve a favorable result.

How We Can Help

Our medical experts will review your case and get to know the variations of your condition. This translates into helping the legal experts know how to argue your case and fight for the benefits you deserve.