In this article, the author reviews the early and late manifestations of syringobulbia, the differential diagnosis of syringomyelia and hydromyelia, and the 90% chance of long-term stabilization or improvement with surgical treatment in Chiari-related syringomyelia. Syringomyelia and associated conditions, such as arachnoiditis and the Chiari I anomaly, are now readily diagnosed by MRI. After successful craniovertebral decompression, most patients with pressure dissociation headaches and blackouts improve. However, the large variety of other symptoms often present may not improve after surgery. MRI might overestimate the degree of tonsillar ectopia in Chiari I malformation. New MRI techniques allow for the identification of subtle arachnoid scarring or tethers in the subarachnoid space in idiopathic syringomyelia patients.
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• MRI is the diagnostic modality of choice for syringomyelia and associated conditions, such as Chiari I anomaly or arachnoiditis, and for the differential diagnosis of syringomyelia and hydromyelia.
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• Preventive measures for the development of syringomyelia include the careful use of epidural anesthesia and the avoidance of a traumatic or prolonged labor and maneuvers that may induce “craniospinal” dissociation, such as Valsalva maneuver.
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• Advanced cases of disability in patients are seen less frequently nowadays due to the major impact that MRI has had in early diagnosis and improvement in surgical techniques.
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• Chiari I patients may suffer from nonsuboccipital headaches, not triggered by the Valsalva maneuver.
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• Some patients show progressive neurologic deterioration and disabling pain despite proper surgical drainage of the syrinx and correction of the associated craniovertebral anomaly. Pain is a frequent and disabling manifestation of syringomyelia and a persistent symptom.
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• In children with Chiari I malformation and syringomyelia, the presence of comorbidities at birth has a negative impact on the result of surgical procedures.
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• Idiopathic syringomyelia can be resolved by section of scars or tethers visualized in the subarachnoid space by new MRI techniques.
Historical note and terminology
Ollivier d’Angers first coined the name "syringomyelia" in 1824 (42), but the condition was first recognized by Stephanus in 1545 (57). Schultze first described its clinical picture (55); its relation to Chiari malformation was first outlined by John Cleland (11). Abbe performed the first reported surgical drainage of a syrinx in 1891 (01), although claims were made that Horsley aspirated a syrinx in 1890 (45). The “hydrodynamic” theory of syringomyelia was proposed by Gardner (14) and modified by Williams' “craniospinal pressure dissociation” theory (65).
Syringomyelia is a rare condition defined as the development of a fluid-filled cavity located inside the spinal cord; the fluid is similar to cerebrospinal fluid (26). The cavity lies outside the central canal and does not have ependymal lining; however, it may have a partial connection with the central canal. Hydromyelia, or “dilated central canal” or “slit-like syrinx,” is a thin cavity lined partially or completely by ependymal cells and located at the place of the central canal, which should have disappeared after birth. “Communicating” or foraminal syringomyelia refers to cavities with a direct communication with the fourth ventricle through the obex and is usually associated with hindbrain malformations. “Noncommunicating” or nonforaminal syringomyelia refers to cavities without communication with the fourth ventricle and is usually secondary to trauma and tumors of the spinal cord but is also associated to hindbrain malformations. The famous golfer Robert “Bobby” Jones suffered from syringomyelia and it has been speculated that the well-known cellist Jacqueline du Pret might have suffered from syringomyelia rather than multiple sclerosis.