encephalitis lethargica; sleeping sickness; von Economo's disease

Etiology

unknown, ? viral

Epidemiology

• epidemics documented in early 1915-1920 in France, Austria, England
• practically disappeared by 1930s
• sporadic cases still occur

Pathology

• congestion & inflammation of grey matter
  • cerebral cortex
  • basal ganglia
  • brainstem
  • cervical spinal cord (sometimes)
• perivascular infiltration with lymphocytes & plasma cells
• inflammation greatest in the midbrain
• neuronal degeneration in
  • substantia nigra
  • oculomotor nuclei
  • lentiform nucleus
  • hypothalamus
• gliosis accompanying neuronal degeneration

Clinical manifestations

• fever
• somnolence, lethargy
• coma may occur
• oculomotor palsies
• meningeal irritation
• headache

Complications

• death
• post-encephalitic parkinsonism

Management

• symptomatic
• Sinemet & other anti-Parkinson agents may be useful

More general terms

• encephalitis

Additional terms

• post-encephalitic parkinsonism

Patient information

encephalitis lethargica patient information