It may be that manipulation can cause dissection, or it may be that the dissection is already present in some people who seek manipulative treatment. At this time, conclusive evidence does not exist to support either a strong association between neck manipulation and stroke, or no association. However, the two most authoritative articles on the subject, recent literature reviews and analyses, conclude that although there exists an association between stroke from vertebral artery dissection and chiropractic adjustment, there is insufficient evidence to indicate that the adjustment caused the dissection. A recent meta-analysis of the published data on the topic also looked to apply Hills criteria for assigning causation in biological systems to the relationship between chiropractic adjustment and cervical artery dissection, finding that the relationship did not fulfill the required criteria for causality. Mechanism
The vertebral arteries arise from the subclavian artery, and run through the transverse foramen of the upper six vertebrae of the neck. After exiting at the level of the first cervical vertebra, its course changes from vertical to horizontal, and then enters the skull through the foramen magnum. Inside the skull, the arteries merge to form the basilar artery, which joins the circle of Willis. In total, three quarters of the artery are outside the skull; it has a high mobility in this area due to rotational movement in the neck and is therefore vulnerable to trauma. Most dissections happen at the level of the first and second vertebrae.
Psychogenic pruritus, also known as psychogenic itch or functional itch disorder is pruritus not associated with a dermatologic or systemic cause. More often than not, it is attributed to a psychiatric cause. Psychogenic pruritus is not the same as neuropathic itch though both are conditions which require more research. This condition is not explained well in DSM-V and is typically considered a diagnosis of exclusion. This condition is not well-studied and it is difficult to ascertain as it is seen by both dermatologists and psychiatrists. In order to provide some consensus to this condition, The French Psychodermatology Group have created diagnostic criteria for this condition. Symptoms
Psychogenic pruritus typically appears as itching on the face and on the extensor surfaces of the body. This includes the back side of the arms, the abdomen, the side of the legs and the upper back and shoulders. These areas are more frequent because they are within hands reach. Diagnosis
When considering the diagnosis of psychogenic pruritus, it is important to rule out medical, dermatologic and neuropathic causes. A strong history should be obtained and appropriate labwork should be drawn. One should consider drawing for a CBC (Complete Blood Count), ESR (Erythrocyte Sedimentation Rate), liver, renal and thyroid panel as abnormalities with any can contribute to pruritus. Pruritus can be seen with hepatic and renal disease such as cholestasis, alcoholic liver disease, primary biliary cholangitis, hepatitis B and C, and chronic kidney disease.