However, despite their benefits, information learned from MRI and SPECT during the beginning of CBD progression tend to show no irregularities that would indicate the presence of such a neurodegenerative disease. FDOPA PET is used to study the efficacy of the dopamine pathway.Despite the undoubted presence of cortical atrophy (as determined through MRI and SPECT) in individuals experiencing the symptoms of CBD, this is not an exclusive indicator for the disease. Thus, the utilization of this factor in the diagnosis of CBD should be used only in combination with other clinically present dysfunctions. MRI
MRI images are useful in displaying atrophied portions of neuroanatomical positions within the brain. As a result, it is especially effective in identifying regions within different areas of the brain that have been negatively affected due to the complications associated with CBD. To be specific, MRI of CBD typically shows posterior parietal and frontal cortical atrophy with unequal representation in corresponding sides. In addition, atrophy has been noted in the corpus callosum.Functional MRI (fMRI) has been used to evaluate the activation patterns in various regions of the brain of individuals affected with CBD. Upon the performance of simple finger motor tasks, subjects with CBD experienced lower levels of activity in the parietal cortex, sensorimotor cortex, and supplementary motor cortex than those individuals tested in a control group. SPECT
SPECT is currently being used to try to detect CBD. With many patients of CBD, there are areas in the basal ganglia which have difficulties receiving dopamine, typically asymmetrically.
Grisels syndrome is a non-traumatic subluxation of the atlanto-axial joint caused by inflammation of the adjacent tissues. This is a rare disease that usually affects children. Progressive throat and neck pain and neck stiffness can be followed by neurologic symptoms such as pain or numbness radiating to arms (radiculopathies). In extreme cases, the condition can lead to quadriplegia and even death from acute respiratory failure. The condition often follows soft tissue inflammation in the neck such as in cases of upper respiratory tract infections, peritonsillar or retropharyngeal abscesses. Post-operative inflammation after certain procedures such as adenoidectomy can also lead to this condition in susceptible individuals such as those with Down syndrome. Pathophysiology
Pathophysiology of this disease consists of relaxation of the transverse ligament of the atlanto-axial joint. Diagnosis
Diagnosis can be established using plain film x-rays as well as CT scan of the neck/cervical spine. Children with Down syndrome have inherently lax ligaments making them susceptible to this condition. In select cases, these children may require pre-operative imaging to assess the risk for complications after procedures such as adenoidectomy. Treatment
Treatment includes anti-inflammatory medications and immobilization of the neck in addition to treatment of the offending infectious cause (if any) with appropriate antibiotics. Early treatment is crucial to prevent long-term sequelae. Surgical fusion may be required for residual instability of the joint. References

Grisel P. Enucléation de latlas et torticollis naso-pharyngien Presse Med 1930;38:50–4. Mathern GW, Batzdorf U. Grisels syndrome: Cervical spine clinical, pathologic, and neurologic manifestations. Clin Orthop Relat Res. 1989 Jul;(244):131-46.