Mitochondrial disorders Home A-Z Health Information Health Library A-Z Mitochondrial Disorders Overview Mitochondrial neurological disorders are a group of conditions that affect the brain and nervous system due to dysfunction of the mitochondria, the energy-producing structures within cells. They may affect brain, spinal cord, nerves, or muscles and produce a cluster of symptoms. Mitochondrial neurological disorders can be caused by mutations in either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) and may be inherited in various patterns. The various mitochondrial disorders affecting nervous system are Mitochondrial myopathies (muscle disorders)Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)Kearns-Sayre syndrome (KSS)Leigh syndromeProgressive external ophthalmoplegia (PEO)Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)Mitochondrial DNA depletion syndromeFriedreich's ataxiaHereditary spastic paraplegiaMitochondrial optic neuropathies (e.g., Leber hereditary optic neuropathy) Cause Caused by genetic mutations Risk factors Genetic mutations in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA); however, many cases occur without a family historyEnvironmental toxinsInfectionsAging can negatively affect mitochondrial function and increase the risk of secondary mitochondrial dysfunction (SMD) Symptoms Muscle weakness and paralysisSeizures and epilepsyCognitive impairment and dementiaVision loss and blindnessHearing loss and deafnessAtaxia (coordination and balance problems)Spasticity and stiffnessPeripheral neuropathy Specialist to approach Neurologist Diagnosis Clinical evaluationMRI brainMuscle biopsy in mitochondrial myopathyGenetic testing Treatment Supportive care- RehabilitationGenetic counselling