Here is all you need to know about internal decapitation
As Rachel Pighills is desperate to raise £135,000 for life saving surgery in Barcelona, we take a look at her condition.
In full, Rachel, 33, has: craniocervical instability, sub-axial instability, atlanto axial instability, atlas assimilation, basilar invagination causing severe brain stem compression, platybasia, chiairi malformation, scoliosis and cervical medullary syndrome.
Atlantoaxial instability is characterized by excessive movement at the junction between the atlas (C1) and axis (C2) as a result of either a bony or ligamentous abnormality.
Craniocervical instability is a pathological condition of increased mobility at the craniocervical junction, the area where the skull meets the spine. Platybasia is a spinal disease of a malformed relationship between the occipital bone and cervical spine.
Cervical Medullary Syndrome is caused by brainstem compression, deformation, infection or inflammation.
Chiari malformation is where the lower part of the brain pushes down into the spinal canal. This causes basilar invagination, which happens when the top of the spine pushes into the base of the skull.
If Rachel looks or turns severely to the left, her brain stem could partially dislocate. If it fully dislocates, the spinal column could separate from the skull, causing internal decapitation and possible death.
Atlanto-occipital dislocation, orthopedic decapitation, or internal decapitation describes ligamentous separation of the spinal column from the skull base.
It is so serious, because when the ligaments in this area are severed, the head might move around more, leading to damage in the lower brain stem, a vital area that controls breathing.
It is possible for a human to survive such an injury; however, only 30 per cent of cases do not result in immediate death. Last January, Brock Meister, 22, from North America, survived following an internal decapitation sustained during a car crash. And in 2016, Killian Gonzalez, a four-year-old from Idaho, also survived following a car crash.