Part 3: Mitochondrial dysfunction
Mitochondrial dysfunction is a key contributor in many epilepsy syndromes, particularly metabolic/degenerative forms and some drug-resistant cases.
Magnetic resonance spectroscopy consistently shows elevated lactate (from anaerobic glycolysis), reduced phosphocreatine (high-energy phosphate reserve), and lower N-acetylaspartate (neuronal integrity marker) in epileptic foci and even non-lesional brain.
This reflects chronic energy deficit and inefficient oxidative phosphorylation.
The core mechanisms seem to be once again (similar to bipolar for example):
-Impaired pyruvate dehydrogenase complex (PDH).
PDH converts pyruvate (from glycolysis) to acetyl-CoA for the TCA cycle. Deficiency (genetic or acquired) → pyruvate shunts to lactate → elevated brain lactate, acidosis.
Electron transport chain (ETC) defects: Complexes I–IV disruptions reduce ATP synthesis, increase reactive oxygen species (ROS).
-mtDNA mutations/polymorphisms:
POLG (mitochondrial polymerase gamma): Most common nuclear gene causing mitochondrial epilepsy.
MT-ATP6 (m.8993T>G/C)
MT-TL1 (m.3243A>G)
Basically: Low ATP → failure of energy-dependent processes:
-Na /K -ATPase pump collapse → membrane depolarization, reduced seizure threshold.
-Calcium homeostasis disruption → excessive neuronal firing.
-Impaired neurotransmitter clearance (glutamate transporters need ATP).
Astrocyte dysfunction → reduced glycogen storage, poor buffering.
This is exactly why high fevers trigger seizures in so many people with epilepsy (metabolic demands skyrocket in an already compromised system).