Frequently Asked Questions on Topics for the Entire Family, for your health and well being and more! FAQs - Primary Lateral Sclerosis What is PLS? What are the symptoms? How does PLS cause my symptoms? How severe will my symptoms get? How is PLS diagnosed? How is PLS different from ALS? What is the treatment? What is the life expectancy? What other conditions cause spasticity and weakness of muscles? Does stress affect symptoms? Is depression common? Can PLS affect sexual function? Can I donate blood? Is PLS more prevalent in certain ethnic groups? Acute Intermittent Porphyria (AIP) If there is a subject you think we need in the FAQ section, please contact us and let us know!