Situation

Mr. J.M. is a 32-year-old man from Mexico who was born   with a deformity at the base of the skull. He was told by his neurosurgeon in Mexico that he had basilar invagination of the skull and over time he would become completely paralyzed due to pressure on the spinal cord from a deformed bone (Figures 9 and 10). The medical term for this condition is skull base basilar invagination with myelopathy. He was referred to Dr. McCormack.

Figure 9. MRI of head. "x" indicates abnormal bone pressing against the brainstem causing paralysis. Double "x" indicates brainstem compression.

Figure 10. CT scan of junction of the head with the spine. "x" indicates abnormal bone projecting into the patient’s head and brainstem region.

Treatment

On examination the patient had difficulty swallowing and could barely walk. His studies demonstrated pressure on his brainstem from the second cervical vertebrae. In staged operations, Dr. McCormack first relieved the pressure on his brainstem by using a microscope and dissecting the bone off the spinal cord through the patient’s mouth (Figure 11). The base of the skull was reconstructed using the patient’s own rib bone to fuse the skull to the spine and a titanium rod (Figure 12). The patient regained all his strength and could eat normally after surgery.

Figure 11. CT scan after removal of the abnormal bone to relieve pressure on the brainstem. The surgery was performed through the patient’s mouth using a microscope.

Figure 12B. Dr. McCormack then used a titanium rod to fuse the skull to the spine.

Figure 12A. The base of the skull was reconstructed using the patient’s own rib bone.