It is the junction of the skull/cranium and the uppermost part of the cervical spine. It is where the brain continues as the spinal cord. Thereby, this region of the neural axis controls vital actions such as respiration, blood pressure, nerves of all 4 limbs and the nerves of the bowel/bladder.
Evidently, it is the most complex region of the spine containing in addition the vertebral arteries which supply blood to the back/lower portion of the brain and the upper part of the spinal cord.
Tumors-discussed in section on spinal tumors.
Trauma-
Requirement of surgery would depend on the extent of bony trauma and spinal cord compression, if any.
Some traumatic pathologies of the craniospinal junction would require a screw fixation of a fractured bony fragment (Type II Odontoid Fracture) through a small incision in the front of the neck.
Some others would require transoral removal of bony fragments compressing the spinal cord followed by screw-rod fixation of the upper 2/3 cervical bodies rarely extending to also include screws in the skull.
Some traumatic pathologies of the craniospinal junction would require a posterior approach only involving screw-rod fixation of the upper 2/3 cervical bodies rarely extending to also include screws in the skull.
Infection (commonly Tuberculosis in the developing/underdeveloped world) and Inflammatory (Rheumatoid Arthritis)-
Only medical management is required if there is no instability on flexion/extension x-rays and if there is no significant spinal cord compression on MRI.
Surgery would involve transoral decompression of the spinal cord if there is anterior spinal cord compression on the MRI followed by screw-rod fixation of the upper 2/3 cervical bodies rarely extending to also include screws in the skull. If there is no anterior compression, only posterior surgery is required.
Congenital
Reducible dislocation of the craniospinal junction reducing to normal position on extension of the neck is treated by a posterior surgery alone involving screw-rod fixation of the upper 2 cervical bodies in a reduced normal position.
Irreducible dislocation of the craniospinal junction with anterior bony compression on the spinal cord requires transoral removal of bony compression on the spinal cord followed by screw-rod fixation of the upper 2/3 cervical bodies rarely extending to also include screws in the skull.
Soft-tissue congenital anomaly of the craniospinal junction includes Chiari Malformation which is herniation of the lowest part of the brain (cerebellar tonsils) into the spinal canal thus leading to blockage of CSF exit from the central canal of the spinal cord resulting in CSF accumulation in the spinal cord (syringomyelia). Surgery is posterior and involves bony/dural decompression and coagulation/shrinkage/resection of the herniated cerebellar tonsils to unblock the exit of CSF from the central canal of the spinal cord.
Only pain
Subtle symptoms may include
Advanced symptoms
Already discussed with pathologies.
The patient has to wear a collar for some time following the surgery to avoid aggressive neck movements.
An aggressive exercise/physiotherapy regimen is crucial to maximizing recovery post-operatively and needs to start from post-operative day 1.
The first purpose of surgery is to prevent further neurological deterioration. Patients with no significant symptoms pre-operatively should be near normal immediately post-operatively.
Recovery in patients who already have symptoms of spinal cord damage depends on extent of symptoms, extent of spinal cord damage on pre-operative MRI and precision of surgery. Recovery will happen slowly over many months and is maximized by an aggressive exercise/physiotherapy regimen. However, the extent and time-period of recovery is unpredictable. But it must be mentioned that many patients exhibit miraculous improvement over a few months. And therefore, it is never too late to try.
Advanced symptoms such as bowel/bladder involvement and gross weakness/paralysis with wasting or loss of muscle bulk are unlikely to reverse completely. Therefore, it is imperative that patients undergo identification and surgery for this problem before developing such advanced symptoms.
There are some medications for residual symptoms such as spasticity/heaviness of the legs, paraesthesias or abnormal sensations, burning sensations, nerve pain radiating along the arms or legs.
