A typical cause of PTS would be a car accident or similar trauma involving a whiplash injury.What can make PTS difficult to diagnose is the fact that symptoms can often first appear long after the actual cause of the syrinx occurred (e.g., a car accident occurring and then the patient first experiencing PTS symptoms such as pain, loss of sensation, and reduced ability on the skin to feel varying degrees of hot and cold a number of months after the car accident). Pathogenesis
The pathogenesis of syringomyelia is debated. The cerebrospinal fluid also serves to cushion the brain. Excess cerebrospinal fluid in the central canal of the spinal cord is called hydromyelia. This term refers to increased cerebrospinal fluid that is contained within the ependyma of the central canal. When fluid dissects into the surrounding white matter forming a cystic cavity or syrinx, the term syringomyelia is applied. As these conditions coexist in the majority of cases, the term syringohydromyelia is applied. The terms are used interchangeably.It has been observed that obstruction of the cerebrospinal fluid spaces in the subarachnoid space can result in syrinx formation, and alleviation of the obstruction may improve symptoms. A number of pathological conditions can cause an obstruction of the normal cerebrospinal fluid spaces. These include Chiari malformation, spinal arachnoiditis, scoliosis, spinal vertebrae misalignment, spinal tumors, spina bifida, and others. The reasons that blockage of the cerebrospinal fluid space within the subarachnoid space can result in syrinx formation are not fully understood although a small posterior fossa is one known cause.
However, the association with chromosome 22q11 deletion (DiGeorge Syndrome) implies that a genetic component is likely in certain cases. Esophageal atresia also occurs in some patients with double aortic arch. Diagnosis
Prenatal diagnosis (fetal ultrasound):
Today the diagnosis of double aortic arch can be obtained in-utero in experienced centers. Scheduled repair soon after birth in symptomatic patients can relieve tracheal compression early and therefore potentially prevent the development of severe tracheomalacia. Chest X-ray:
Plain chest x-rays of patients with double aortic arch may appear normal (often) or show a dominant right aortic arch or two aortic arches . There might be evidence of tracheal deviation and/or compression. Sometimes patients present with radiologic findings of pneumonia. Barium swallow (esophagraphy):
Historically the esophagram used to be the gold standard for diagnosis of double aortic arch. In patients with double aortic arch the esophagus shows left- and right-sided indentations from the vascular compression. Due to the blood-pressure related movement of the aorta and the two arches, moving images of the barium-filled esophagus can demonstrate the typical pulsatile nature of the obstruction. The indentation from a dominant right arch is usually deeper and higher compared to the dent from the left arch. Bronchoscopy:
Although bronchoscopy is not routinely done in patients with suspected or confirmed double aortic arch, it can visualize sites and severity of pulsatile tracheal compression. Echocardiography:
In babies under the age of 12 months, echocardiography is considered to be sensitive and specific in making the diagnosis of double aortic arch when both arches are open.