Syrinxes usually result from lesions that partially obstruct cerebrospinal fluid flow [7-9
]. At least half of syrinxes occur in patients with congenital abnormalities of the craniocervical junction (e.g., herniation of cerebellar tissue into the spinal canal, called Chiari malformation), brain (e.g., encephalocele), or spinal cord (e.g., myelomeningocele) [6,10
]. For unknown reasons, these congenital abnormalities often expand during the teen or young adult years. A syrinx can also develop in patients who have a spinal cord tumor, scarring due to previous spinal trauma, or no known predisposing factors [11-15
]. About 30% of people with a spinal cord tumor eventually develop a syrinx [16
Syringomyelia is a paramedian, usually irregular, longitudinal cavity. It commonly begins in the cervical area but may extend downward along the entire length of the spinal cord. Syringobulbia, which is rare, usually occurs as a slit-like gap within the lower brain stem and may disrupt or compress the lower cranial nerves or ascending sensory or descending motor pathways [4,17
Symptoms usually begin insidiously between adolescence and age of 45 [16
]. Syringomyelia develops in the center of the spinal cord, causing a central cord syndrome. Pain and temperature sensory deficits occur early but may not be recognized for years. The first abnormality recognized may be a painless burn or cut. Syringomyelia typically causes weakness, atrophy, and often fasciculations and hyporeflexia of the hands and arms; a deficit in pain and temperature sensation in a capelike distribution over the shoulders, arms and back is also characteristic [4
]. Light touch and position and vibration sensation are not affected. Later, spastic leg weakness develops. In this study, the presenting symptoms were cervical pain, headache, and stiffness in the back, shoulders, arms, or legs. Additionally, arm or leg weakness and a loss of the ability to feel extremes of hot or cold were observed, but most symptoms were ambiguous. Thus, it is very difficult to diagnose the presence of a syrinx by the presenting symptoms, although this diagnosis should be kept in mind.
A syrinx is suggested by an unexplained central cord syndrome or other characteristic neurologic deficits, particularly pain and temperature sensory deficits in a capelike distribution [4,16,17
]. MRI of the entire spinal cord and brain should be performed. Gadolinium enhancement is useful for detecting any associated tumor [16
Underlying problems (e.g., craniocervical junction abnormalities, postoperative scarring, or spinal tumors) are corrected when possible [6,10
]. Surgical decompression of the foramen magnum and upper cervical cord is the only useful treatment, but surgery usually cannot reverse severe neurologic deterioration.
The golden standard diagnostic tool for the syrinx is MRI of the spinal cord and brain with gadolinium [16
]. Currently, imaging techniques for MRI have greatly improved, including techniques for whole spine sagittal scanning. The overall diagnostic proportion of the syrinx was only 66.7%; this proportion was unaffected by the length of the syrinx. It means that low detection of the syrinx was not related with unintended fault. This was more reasonable by the significant association between the detection proportion and the type of MRI. In cervical MRI or whole spine sagittal scanning with focusing cervical spine MRI, cervical lesions were not main concerned lesion. But, in the whole spine sagittal scanning with focusing lumbar spine MRI, the cervical lesion is not the main concern of the examiners or reporters. So, cervical lesions such as a syrinx in whole spine sagittal scanning with focusing lumbar spine MRI were easily dismissed.
In conclusion, a syrinx is an easily detectable disease by MRI, but the missed diagnosis proportion of the syrinx was relatively high. Thus, we suggest that the physician should consider syrinx as a possible diagnosis, as the symptoms are vague. Furthermore, physicians should more carefully review whole spine sagittal scanning MR images, so as to not miss the syrinx diagnosis.