Fig. 2.

Brain proton MR spectroscopy: (A) mild pathological accumulation of lactate was detected by ¹H-MRS (single voxel PRESS localization sequence, TR = 1500 ms, TE = 288 ms) in the cerebrospinal fluid of the lateral ventricles (B). Venous serum lactate in LHON patients (n = 20) and in the proband (normal range 5.8–22 mg/dl) (C). Muscle histopathology: H&E, COX/SDH and SDH stains show some variability of fiber caliber and slight subsarcolemmal increase of SDH (D). Respiratory chain complexes activity in skeletal muscle is normalized for citrate synthase (CS) activity (E). Asterisks indicate statistical significance (p < 0.05).