🧠 Chiari Malformation (CM)

Chiari malformation is a structural abnormality where a part of the cerebellum (the brain’s balance center) extends downward through the foramen magnum — the natural opening at the base of the skull.
This can put pressure on the brainstem and spinal cord, disrupting normal flow of cerebrospinal fluid (CSF) and causing neurological symptoms.

Types

• Chiari Type I – Most common and often detected in teens or adults.

• Chiari Type II, III, IV – Usually more severe, often diagnosed in infancy, and associated with other congenital brain or spinal abnormalities.
  
  

Causes

• Congenital (by birth) – due to abnormal skull development.

• Acquired (secondary CM) – rare; can occur later in life from:

  • CSF leakage (low-pressure in brain)

  • Injury or infection leading to pressure changes
    
    

Who Is at Risk

• Females (slightly more common)

• Family history of Chiari malformation
  
  

Symptoms

Symptoms depend on how much the cerebellum and brainstem are compressed.
Some people have no symptoms; others develop symptoms that come and go or gradually worsen.

Common symptoms include:

• Headache at the back of the head

  • Worsens with coughing, sneezing, or straining

  • May radiate to the neck and shoulders

• Neck pain or stiffness

• Dizziness or fainting

• Balance and coordination problems

• Blurred or double vision, light sensitivity, or “floaters”

• Difficulty swallowing or speaking

• Sleep apnea or breathing pauses

• Numbness or weakness in limbs

• Scoliosis (curved spine)

• Urinary incontinence (in severe cases)
  
  

Diagnosis

Diagnosis involves:

• Neurological examination (checking balance, coordination, reflexes)

• MRI brain and spine – main imaging to show herniation of cerebellar tonsils

• CT scan – may be used to assess bone structure or rule out other causes
  
  

Treatment

Treatment depends on symptom severity:

• Observation: If asymptomatic or mild

• Medical therapy: For headache or pain control

• Surgery:

  • Posterior fossa decompression — enlarges space around the cerebellum to relieve pressure and restore CSF flow

  • Duraplasty or CSF diversion (shunt) may be added if needed
    
    

Home & Lifestyle Advice

• Take medications only as prescribed

• Avoid activities that worsen dizziness or headache

• Get up slowly from lying or sitting positions

• Stay well hydrated

• Avoid nicotine and tobacco

• Follow up regularly with your neurologist or neurosurgeon

• Consider joining a Chiari malformation support group
  
  

When to Seek Immediate Medical Help

Call emergency services if you have:

• Sudden weakness or numbness in arms or legs

• Slurred speech, double vision, or dizziness with a severe headache

• New or worsening neurological symptoms