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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• Brain lesions facts
• Brain anatomy
• What are brain lesions?
• What causes brain lesions?
• What are the types of brain lesions?
• What are the symptoms of brain lesions?
• How are brain lesions diagnosed?
• What is the treatment for brain lesions?
• Can brain lesions be prevented?
• What is the prognosis for brain lesions?
• Find a local Doctor in your town
• Brain Lesions (Lesions on the Brain) Index

Symptoms of a brain lesion depend upon what part of the brain is affected. Large parts of the brain can be involved in some diseases and there may be relatively few symptoms. Alternatively, very tiny lesions may be catastrophic if they occur in a critical part of the brain. For example, the reticular activating system (RAS) is a tiny area located within the brainstem that is effectively the master on/off switch of the brain. If a midbrain stroke affects this area, the result is permanent coma. A patient needs the RAS and one functioning hemisphere of the cortex to be awake. If the patient is unconscious, then the RAS isn't working or there is significant damage to both sides of the brain.

Initial signs and symptoms of a brain lesion are often non-specific and may include:

• Headache
  
  
• Nausea
  
  
• Fever (if an infection is present)
  
  
• Neck pain and stiffness (if the meninges are inflamed)
  
  
• Affected vision (if there is damage along the pathway from the optic nerve to the occiput)
  
  
• Affected speech (if there is damage to Broca's area) Speech includes saying and understanding words.
  
  
• Difficulty making words (due to weakness of the muscles that control the mouth)
  
  
• Weakness or paralysis to one side of the body
  
  
• Seizures
  
  
• Memory loss and confusion
  
  
• Personality changes, loss of concentration, aggression and loss of personal control
  
  
• Worst headache of your life

If any of these symptoms arise suddenly, the person should be evaluated immediately, usually in an emergency department that is well equipped (CT scanner, MRI, easy access to neurosurgeons and neurologists).