Spontaneous resolution of a Chiari malformation with syringomyelia

Abstract

The Chiari I malformation (CM-I) is characterised by overcrowding of the posterior fossa and descent of the cerebellar tonsils and is associated with syringomyelia. With the increasing availability of magnetic resonance imaging, CM-I is placing a growing burden on neurosurgical services. However, its natural history remains poorly understood, and the timing and nature of surgical intervention is controversial. We present a case of a significant, symptomatic CM-I with associated syrinx which underwent complete spontaneous resolution over a 4-year period. Spontaneous regression of Chiari malformation and syringomyelia is exceedingly rare; a literature review reveals 15 other cases and only one case which underwent complete resolution. The present case and literature review suggest a more benign natural history of CM-I and support a more conservative approach to its management. Further studies are required to determine whether any factors can predict resolution for certain patient cohorts.

Natural History of Chiari 1 Deformity

“…There have been numerous reported cases of spontaneous resolution of Ch1 with or without associated syringomyelia. 2,5,12,[14][15][16][17][18][19] Cases 2 and 3 represent spontaneously resolving Ch1, supporting the role of conservative management in asymptomatic patients. The process of spontaneous resolution of Ch1 is not clearly understood.…”

“…2 Hans Chiari first described the disease in 1891 3 as posterior fossa overcrowding with cerebellar tonsil descent via the foramen magnum-descent of tonsils more than 5 mm inferior to the foramen magnum is considered the radiological cutoff for diagnosis. 4,5 Pain either in the form of a headache located in the suboccipital and upper cervical regions or nonradicular type of pain in the shoulder, back, and limbs are usually the common presenting symptoms with exacerbation of headache by Valsalva maneuvers. 2 The compression of neural structures in the posterior fossa is believed to be the cause of the symptoms and signs, such as sensory and motor deficits, ataxia, arching of the neck, and lower cranial nerve abnormalities.…”

“…Chiari type 1 deformity is traditionally considered a congenital abnormality associated with the cerebellar tonsils being displaced downward into the cervical canal 2 . Hans Chiari first described the disease in 1891 3 as posterior fossa overcrowding with cerebellar tonsil descent via the foramen magnum—descent of tonsils more than 5 mm inferior to the foramen magnum is considered the radiological cutoff for diagnosis 4,5 . Pain either in the form of a headache located in the suboccipital and upper cervical regions or nonradicular type of pain in the shoulder, back, and limbs are usually the common presenting symptoms with exacerbation of headache by Valsalva maneuvers 2 .…”