Neuromuscular and neurodegenerative (NMND) disorders are diseases that cause progressive damage to the central nervous system leaving patients with symptoms that negatively affect everyday living with death almost inevitable. These include amyotrophic lateral sclerosis (ALS), Lewy body dementia (LBD), and Parkinson's disease (PD) with cases expected to increase in the future. Intranasally administered stem cell-derived exosomes/secretome have been seen as potential therapeutic options for these disorders in preclinical animal models. This study sought to observe the efficacy of mesenchymal stem cell-derived exosomes/secretome in patients with ALS, LBD, and PD. Based off these preclinical studies, we conducted a case-controlled series experiment with 86 patients with ALS, LBD, or PD, with the independent variable being the treatment and the dependent variable being the clinical response. These patients were recruited and given intranasal instillations of various MSC-derived exosome/secretome products. Subsequent treatments were given to patients who did not have a response to one product. Patients were followed up at one week, one, two, three, and six months post-treatment. Historical external controls were used for comparison to clinical outcomes. There were no serious adverse events in any patient. A total of 67 of 86 (77%) patients showed a positive clinical response to at least one product. Outcomes were strongly associated with greater treatment frequency for ALS and LBD. Intranasal administration of MSC-derived exosome/secretome products were safe, and most patients showed overall improvement with at least one product. Some patients also saw a substantial decrease in the rate of decline compared to historical controls. These results also give rise to the hypothesis: do MSC-derived exosomes/secretome treatments show efficacy in other NMND disorders? The primary limitation of this study is the 6-month follow-up.