What are the symptoms of Leigh Syndrome, a Subacute Necrotigenic Encephalomyelopathy (Subacute Necrotizing Encephalomyelopathy)?

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Last updated: March 5, 2025View editorial policy

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From the Guidelines

Leigh Syndrome is characterized by a distinct set of symptoms including developmental delay, weakness, lack of muscle tone, movement disorders, difficulty swallowing, seizures, and respiratory problems, which are a result of mitochondrial dysfunction affecting energy production in cells, particularly in the central nervous system. These symptoms can vary in severity and combination among patients, depending on the genetic cause and other factors 1.

Common Symptoms

  • Developmental delay or regression
  • Weakness
  • Lack of muscle tone
  • Movement disorders
  • Difficulty swallowing
  • Seizures
  • Respiratory problems
  • Poor growth
  • Vomiting
  • Irritability
  • Vision and hearing impairments, which may develop as the disease progresses The symptoms of Leigh Syndrome usually begin in infancy or early childhood, though some cases may appear later in childhood or even adulthood 1. The progression of the disease varies but often includes periods of rapid decline triggered by infections or other stressors. Characteristic brain abnormalities appear on MRI, particularly in the basal ganglia, thalamus, and brainstem.

Disease Progression

The disease progression is influenced by the genetic cause, with some patients experiencing a more rapid decline than others. Infections or other stressors can trigger periods of rapid decline, highlighting the importance of early recognition and supportive care.

Importance of Early Recognition

Early recognition of the symptoms of Leigh Syndrome is crucial for diagnosis and supportive care, though there is currently no cure for the disease. A comprehensive understanding of the symptoms and their progression can help guide clinical decision-making and improve patient outcomes.

From the Research

Symptoms of Leigh Syndrome

The symptoms of Leigh Syndrome, a Subacute Necrotizing Encephalomyelopathy, are characterized by a wide variety of abnormalities, including:

  • Severe neurologic problems
  • Psychomotor retardation
  • Seizures
  • Nystagmus
  • Ophthalmoparesis
  • Optic atrophy
  • Ataxia
  • Dystonia
  • Respiratory failure 2
  • Peripheral nervous system involvement, including polyneuropathy or myopathy
  • Non-neurologic abnormalities, such as diabetes, short stature, hypertrichosis, cardiomyopathy, anemia, renal failure, vomiting, or diarrhea 2

Clinical Manifestations

Clinical manifestations of Leigh Syndrome may include:

  • Developmental delay
  • Nervous system dysfunction
  • Respiratory abnormalities, such as aspiration, wheezing, breathing difficulties, gasping, hypoventilation, and apnoea 3
  • Rapid deterioration of cognitive and motor functions, resulting in death due to respiratory failure 4
  • Refractory seizures, which may further complicate morbidity and mortality 5

Age of Onset

The age of onset of Leigh Syndrome can vary, with:

  • Most patients presenting with symptoms between the ages of three and twelve months 4
  • Some patients having adult-onset symptoms 2, 4, 5
  • Some patients having evidence of in utero presentation 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Anaesthetic management of a patient with Leigh's syndrome.

Canadian journal of anaesthesia = Journal canadien d'anesthesie, 1997

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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