Brain metabolic signatures in patients with genetic and nongenetic amyotrophic lateral sclerosis

Aims To study the brain metabolic signature in Chinese amyotrophic lateral sclerosis (ALS) patients and compare the difference in brain metabolic patterns between ALS with and without genetic variants.Methods We included 146 patients with ALS and 128 healthy controls (HCs). All patients with ALS underwent genetic testing to screen for ALS related genetic variants and were then divided into genetic (n = 22) and nongenetic ALS (n = 93) subgroups. All participants underwent brain F-18-FDG-PET scans. Group comparisons were performed using the two-sample t-test model of SPM12.Results We identified a large of hypometabolic clusters in ALS patients as compared with HCs, especially in the bilateral basal ganglia, midbrain, and cerebellum. Moreover, hypometabolism in the bilateral temporal lobe, precentral gyrus and hypermetabolism in the left anterior cingulate, occipital lobe, and bilateral frontal lobe were also found in ALS patients as compared with HCs. Compared with nongenetic ALS patients, genetic ALS patients showed hypometabolism in the right postcentral gyrus, precuneus, and middle occipital gyrus. The incidence of sensory disturbance in patients with genetic ALS was higher than that in patients with nongenetic ALS (5 of 22 [22.72%] vs. 7 of 93 [7.52%], p = 0.036).Conclusions Our investigation provided unprecedented evidence of relative hypometabolism in the midbrain and cerebellum in ALS patients. Genetic ALS patients showed a specific signature of brain metabolism and a higher incidence of sensory disturbance, indicating that genetic factors may be an underlying cause affecting the brain metabolism and increasing the risk of sensory disturbance in ALS.

Automated summary

This study investigated the brain metabolic signature in Chinese amyotrophic lateral sclerosis (ALS) patients, finding hypometabolic clusters in the midbrain and cerebellum as compared to healthy controls. Furthermore, ALS patients showed hypometabolism in the bilateral temporal lobe and precentral gyrus, as well as hypermetabolism in the left anterior cingulate and occipital lobe. Genetic ALS patients exhibited specific brain metabolic patterns and a higher incidence of sensory disturbance compared to non-genetic ALS patients. This study provides unprecedented evidence of ALS-related brain metabolic changes and highlights the role of genetic factors in affecting brain metabolism and sensory disturbance risk in ALS.