Chiari Malformations

What is a Chiari Malformation?

A chiari malformation is a congenital defect (meaning it’s present at birth) in the back of the head, where the spinal cord and brain connect. A chiari malformation is not a deformation of the brain but of the skull. The lower portion of the skull, the posterior fossa, can be too small to adequately hold the lower part of the brain. The compression of the spinal cord and brain stem hinders the flow of spinal fluid which is the reason for symptoms. The tonsils of the cerebellum are forced to protrude into the spinal column. A protrusion of the cerebellar tonsils only have to be 1 millimeter in the spinal canal to produce symptoms.

Chiari Malformation Symptoms

Symptoms of chiari malformations are typically not experienced until a person is in the 20s or 30s, despite the malformation being present at birth. Symptoms can develop sooner or later depending on the cerebellar protrusion. Chiari malformation symptoms are so numerous that proper diagnosis can be tricky, and can be mistaken for other, less serious issues. Some symptoms of chiari malformation include:

  • Headache: a headache is the most common symptom of chiari malformation; beginning in the back of the head and radiating behind the eyes. Bending forward, sneezing,
  • laughing and coughing can worsen the headache.
  • Neck Pain: radiating down the spine and across the shoulders
  • Visual symptoms: double vision, sensitivity to light, blind spots
  • Auditory symptoms: ringing in the ears and decreases in the ability to hear sounds
  • Vocal changes: hoarseness or the inability to regulate the voice when shouting or singing.
  • Dizziness and vertigo
  • Impaired balance: clumsiness, nausea
  • Chronic nausea
  • Difficulty swallowing
  • Foggy thinking
  • Poor memory and poor concentration
  • Frequent or urgent urination

Types of Chiari Malformation

Type I: the upper spinal area and base of the skull are not formed properly.
Type II: a portion of the brain moves down through the bottom of the skull. Myelomeningocele, a severe form of spina bifida, is always present with Type II chiari malformations.
Type III: the most serious type of chiari malformation involves the protrusion or herniation of the hind part of the brain through a defect in the skull.

Diagnosis of Chiari Malformation

The chiari malformation diagnostic process begins with a complete medical history examination and physical examination. The process is followed by a neurological evaluation that will identify specific symptoms and neurological functioning. A Chiari 1 Malformation may have a normal examination. In such a case, determining if Chiari is indeed the problem and if surgery is indeed the best solution becomes difficult. Abnormal neurological examinations identifying patterns of findings will help make linking the problem directly to the brain stem and cervical spinal cord.

Patients may have difficulty with eye movements, balance, sensation, strength and coordination. The reflexes may be too active or not nearly active. Pathological reflexes may also be detected. An MRI is the best diagnostic tool for detecting Chiari malformations.

Treatment of Chiari Malformations

Patients with Chiari malformations do not always show symptoms. Some symptoms of Chiari malformations, such as headache and dizziness, may be treated effectively by medication. It is best to consider surgery when the malformation produces symptoms that interfere with a person’s quality of life. Chiari malformation surgery creates more room for the brain, and relieves compression of the brain stem and spinal cord. This allows the spinal fluid to travel