Amyotrophic Lateral Sclerosis

This article describes the nerve loss underlying amyotrophic lateral sclerosis, its clinical manifestations, examination findings leading to the diagnosis, the expanding role of genetics, and available treatment and patient management.

The cause of neuron death in patients with amyotrophic lateral sclerosis is not known, but many genes are strongly linked to the disease, in both patients with a family history and those with no history. A multistep pathologic process helps to explain the onset of symptoms later in life, even in patients with associated genes. Posttranslational and epigenetic changes are also important factors. Current clinical trials are based on putative pathologic mechanisms, and some newer therapies are gene-based.

Amyotrophic lateral sclerosis has distinctive features and can be diagnosed largely from the history and examination, and true mimics are rare. While the cause of neuronal death is not known, pathogenic and risk factor gene variations are present in a number of patients, and posttranscriptional and epigenetic changes are likely major causative factors. Environmental factors likely contribute, but specific avoidable factors have not been identified. Drugs to slow the progress of the disease are currently limited, but trials for all patients with amyotrophic lateral sclerosis continue, including a focus on genetic factors. Patient management is optimized in multidisciplinary amyotrophic lateral sclerosis clinics, and interventions for nutrition with gastric feeding tubes and respiratory insufficiency by noninvasive ventilation enhance patient comfort.