Cognitive Event-Related Potentials (P300) and Cognitive Impairment in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a progressing disorder characterized by muscle wasting and weakness due to the absence or alteration of the function of dystrophin that protects muscle cells from mechanical stress induced by a movement during contraction. The function of dystrophin isoforms expressed in the brain is not fully understood, but the presence of non-progressing cognitive impairment (including disorders of learning and memory) is a common feature in patients with DMD. To establish correlation between the cognitive event-related potential P300 and psychological evaluation with an intelligence test based on the Stanford Binet Intelligence Quotient (IQ) in patients with DMD and a control group, the respective tests were performed in 31 patients with DMD and 30 controls. The mean age of the group with DMD was 9.35 ± 2.88 years, while that in control children was 9.43 ± 2.69 years (P = 0.89). The IQ was 90.77 ± 12.62 in the DMD group and 106.77 ± 9.62 in the controls (P < 0.0001). The amplitude of the cognitive potential P300 in leads Fz, Cz, and Pz showed no statistically significant differences between the groups. Thus, parameters of the P300 potential and cognitive assessment showed nearly no relationship in patients with DMD vs. controls.