Initially described in 1926 as the appearance of various head and neck complaints due to neck trauma and subsequent compression of the circulation around the third and fourth cervical vertebrae, Barre-Lieou syndrome is now rarely mentioned in the medical literature, and even disputed as a distinct clinical entity. A presumptive diagnosis can be made based on findings from the patient history and physical examination, as no other criteria for the diagnosis exist.
Even though this clinical term was introduced in medical literature almost 100 years ago, the pathogenesis and exact clinical definition remain obscure. It is assumed that symptoms in Barre-Lieou syndrome arise due to the stimulation of sympathetic ganglia and fibers situated in the posterior areas of the C3 and C4 segments of the spine as a result of their protrusion after neck trauma  . Consequently, vasoconstriction of the vascular system, principally of the vertebral artery, and dysfunction of the posterior plexus is proposed as the etiology of symptoms  . Tinnitus, vertigo, and dizziness developing on the grounds of ischemia of the inner ear are some of the most common complaints reported in the literature, as well as headaches, blurred vision, nausea, vomiting and pupillary dilation    may also occur. Other reports have associated the onset of visual deficits (blurred vision, corneal hyperaesthesia, and corneal ulceration), swallowing and respiratory difficulties, as well as pain and cervical muscle spasm (primarily of the sternocleidomastoid muscle) with Barre-Lieou syndrome, but also anxiety, depression, and arrhythmias  . However, more recent studies have disputed the pathogenesis and the resultant appearance of symptoms, as sympathetic stimulation seems to have a minimal effect on the vascular resistance . Moreover, the mentioned symptoms can often be present in many patients due to various other reasons, which is why frequently Barre-Lieou syndrome is not referred to as a distinct term in medicine  .
Because of the ambiguous interpretation of Barre-Lieou syndrome in medical practice, its diagnosis can be difficult to achieve. Having in mind the most important predisposing event - neck trauma  , a detailed patient history could identify injury or severe stretching of the neck. Together with a concomitant onset of dizziness, vertigo, visual disturbances and headaches, a presumptive diagnosis might be made. In addition, a detailed physical examination should be performed, with an emphasis on the range of motion of the head and neck area. Although plain radiography of the cervical spine is readily performed in the setting of neck-related injuries and associated symptoms, data regarding radiographic findings in patients suffering from Barre-Lieou syndrome are scarce, and rare reports have documented only a few patients demonstrating notable lesions (a tear drop fracture and ossification of the posterior longitudinal ligament) .