In a search for evidence of biochemical disorders in regions of postmortem brain other than the motor cortex in amyotrophic lateral sclerosis (ALS), ganglioside patterns were also examined in the frontal, temporal, and parahippocampal gyrus cortex. In 21 ALS brains studied (20 sporadic, 1 familial), abnormal patterns were found in the frontal cortex (81%), temporal cortex (75%), motor cortex (70%), and parahippocampal gyrus cortex (71%). Patterns were established by measuring the percentage distribution of 12 ganglioside species. Two abnormal patterns were detected. One was based on low proportions of GD1b, GT1b, and GQ1b associated with high proportions of GM2 and GD3 (GM1, GD1a, GD2, and GT1a values were normal). The second abnormality was the appearance of Gx. Neither abnormality was seen in the 13 non-ALS control brains. The first, and predominant, abnormality was found in the frontal cortex in 14 brains, and the second was observed in 13 brains; 10 brains showed both abnormalities. These findings thus constitute evidence that the disease process in ALS extends beyond the motor cortex and involves neurons in several brain areas.