Attempts to demonstrate virus in amyotrophic lateral sclerosis

Neurons were isolated from the brain and spinal cord of five patients with clinical and pathologic evidence of amyotrophic lateral sclerosis (ALS). The following studies were carried out to detect the presence of infectious virus. Homogenates of isolated neurons were passaged in several cell lines at different temperatures; isolated neurons were cultured; and supernatant fluids were passaged on the cell lines. Neurons were also cocultivated and fused with continuous cell lines and subsequently passaged; isolated neurons were examined by electronmicroscopy and immunofluorescent techniques, using sera from ALS patients. No evidence of virus was found by these methods.