Chiari Malformation type 1 (CMI) is a congenital anomaly of the hindbrain, in which cerebellar tonsils herniate into the spinal canal. A 47-year-old male patient, who never had an additional disease up to that time sat on a dentist's chair for approximately half an hour with his neck extended for a tooth extraction. While getting up from the chair, the patient developed clinical symptoms. CMI may be undetected for years. Clinical symptoms may have appeared because of keeping the neck in the flexion or extended position for a very long duration of time.