Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) and Lou Gehrig's disease, is a rare disease in which degeneration of motor nerves leads to progressive weakness and wasting of muscles. For the most part, the cause of ALS is unknown. In a small proportion of cases there is a family history of ALS/MND and in an even smaller proportion, the disease is known to result from a change in one of several genes including SOD1, TDP-43 and FUS. An understanding of the genetic basis for one familial form of ALS/MND has permitted the construction of an animal model of ALS/MND (the SOD1 mouse) that has been used extensively to study potential therapeutic agents for the human disease. None of the drugs found to be effective in the mouse have translated into therapeutic benefits for humans with ALS/MND. There are several possible explanations for this finding, one of which is that people with familial and sporadic ALS may respond differently to the same treatment and that the SOD1 mouse may be a better model of familial ALS (or at least familial ALS due to mutations in the SOD1 gene) than it is of sporadic ALS. In an effort to begin to address this question, this review was undertaken in order to ask whether or not people with the familial form of the disease respond differently to treatment compared to people with the sporadic (or non-familial) form of ALS/MND.
We identified all randomized controlled trials in ALS/MND and wrote to the authors to request the data needed to complete this review. Although many more studies were eligible for inclusion, only five authors were willing and able to share the data from their individual randomized controlled trials. Based on the analyses of these data, we find no evidence to support a statistically significant difference in the response to treatment between people with the familial and sporadic forms of ALS/MND.