Amyotrophic lateral sclerosis (ALS) is an incurable neurologic disorder that causes muscle weakness, and disability. In ALS, nerve cells degenerate causing muscle weakness and atrophy. ALS affects the nerve cells that connect the brain to the spinal cord (upper motor neurons), and nerve cells that connect the spinal cord to muscles (lower motor neurons). While some patients with ALS will experience paresthesias (numbness and tingling), most nerves that detect sensations remain intact until the very latest stages of the disease. Over time, people with ALS may experience cognitive problems such as mild dementia, though most stay mentally sharp. Patients with ALS may also experience Parkinson’s-like symptoms, such as tremor and slowness of movement (bradykinesia). When the nerves that control swallowing or breathing become dysfunctional, ALS can become life-threatening or lethal. Damage to these nerves and muscles could lead to aspiration pneumonia, and respiratory failure, respectively.
ALS is also known as Lou Gehrig’s disease because the famed New York Yankee publicly struggled with ALS. Perhaps people alive today are more familiar with another patient who suffered from ALS, the Nobel laureate physicist, Stephen Hawking. Dr. Hawking was well known for being confined to a wheelchair and almost completely paralyzed, requiring a specialized computer interface to communicate.
There is no specific treatment for ALS. Therapy is aimed at controlling the symptoms of the disease. For example, patients may have a breathing tube placed in their neck (tracheostomy) and be connected to a ventilator to help support breathing. Likewise, a feeding tube in the stomach can help patients receive hydration and nutrition if they cannot safely swallow food because of neck muscle weakness. Physical therapists help patients maximize the strength and function. Certain medicines can be used to help treat muscle spasms, sleep problems, pain, and depression.
Since there is no cure for ALS, and really no specific treatment for the condition, there is considerable interest in discovering effective treatments. One of the most promising potential therapies is to use stem cells to treat ALS. Since ALS is caused by the destruction and loss of motor neurons, a reasonable treatment approach is to use stem cells that can become motor neurons and promote motor neuron growth and development.
Recently, researchers conducted two clinical trials to evaluate the safety and feasibility of using bone marrow-derived mesenchymal stromal cells to treat patients with ALS. In one clinical trial, the researchers infused stem cells intravenously, while in the other they infused the stem cells into the cerebrospinal fluid around the spine (intrathecally). Patients in both trials were followed for up to 12 months after the infusion to see if the stem cells caused side effects. During the follow-up period, there were no reports of adverse events related to the treatment. Given the success of these trials, this work clears the way for future clinical trials to study the efficacy of stem cells for treating amyotrophic lateral sclerosis.
Reference: Nabavi et al. (2019). Safety, Feasibility of Intravenous and Intrathecal Injection of Autologous Bone Marrow-Derived Mesenchymal Stromal Cells in Patients with Amyotrophic Lateral Sclerosis: An Open-Label Phase I Clinical Trial. Cell Journal. 2019 Jan;20(4):592-598.