Symptoms vary depending on whether the spinal cord, brain stem, nerves, or blood supply is affected by the pressure. Symptoms become apparent when the neck is bent. They include: * Posterior head pain * Neck weakness * Periods of confusion * Dysphagia or Dysarthria (difficulty swallowing or talking due to loss of muscle control) * Dizziness * Loss of sensation * Cranial nerve disturbance * Loss of the ability to know how joints are positioned * Lhermitte's sign ('electric shock sensation' down the spine and/or to the extremities when the neck is flexed forward) * Weakness of the arms and legs * Orthostatic hypotension * Patients will go into a pool and notice that below their belly button the water is not as cold as it is above. Complications from this can include hydrocephalus, pseudotumor cerebri or syringomyelia because it blocks the flow of fluid around the brain and spinal cord.
Basilar invagination
Nasal glial heterotopia
Microlissencephaly
Lissencephaly
Schizencephaly
Hemihydranencephaly
Exencephaly
Microhydranencephaly