Natural history and postsurgical outcome of syringomyelia

Boiardi, A.; Munari, Leonardo; Silvani, Antonio; Porta, Edoardo La; Scuratti, Alberto; Lodrini, S.

doi:10.1007/bf02336954

Cited by 21 publications

(8 citation statements)

References 21 publications

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“…Could it be that higher recurrence rates obtained earlier are merely due to more severe pre-operative neurological deficits? Even though postoperative improvements of function are less likely to occur in patients with severe pre-operative deficits and a long history [12,43], we could not demonstrate a correlation between clinical recurrence rates and pre-operative deficits or Karnofsky Scores.…”

Section: Discussioncontrasting

confidence: 71%

The surgical treatment of Chiari I malformation

et al. 1996

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A retrospective study was undertaken on 133 patients with a Chiari I malformation treated within the last 16 years at the Departments of Neurosurgery at the Nordstadt Hospital Hannover, Germany, and the University of California, Los Angeles, U.S.A. Ninety-seven patients presented with symptoms related to accompanying syringomyelia and 4 with associated syringobulbia. They underwent 149 surgical procedures and were followed for a mean of 39 +/- 52 months. A decompression at the foramen magnum was performed in 124 patients, while 22 of those with syringomyelia were treated by shunting (7 syringosubarachnoid shunts, 15 syringoperitoneal or -pleural shunts), and 3 by ventriculoperitoneal shunts for hydrocephalus. Except for ventriculoperitoneal shunting, at least a short-term decrease in size of an associated syrinx was observed for all procedures in the majority of cases. However, no long-term benefit was observed for syrinx shunting operations. The best clinical long-term results were obtained with decompression of the foramen magnum in patients with (86% free of a clinical recurrence) and without syringomyelia (77% free of a clinical recurrence). We advise against syrinx shunting, a large craniectomy, and obex plugging which are associated with higher recurrence rates. Instead, surgery should consist of a small craniectomy, opening of the dura, archnoid dissection to establish normal cerebrospinal fluid (CSF) outflow from the 4th ventricle, and a fascia lata dural graft.

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Section: Discussioncontrasting

confidence: 71%

The surgical treatment of Chiari I malformation

et al. 1996

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“…Untreated patients examined during the era of computerized tomography myelography and MR imaging experience progression with an incidence of 11 to 24% per year. [4,9,17] Despite the relatively short follow-up period in this study, the improvement in neurological signs and symptoms has been sustained at a higher level than could be expected from the natural history of the condition, with stable or improved neurological function in all patients. The surgical procedure consistently corrected the pathophysiological consequences of the Chiari I malformation, induced remission of the syrinx, and stabilized the patient's clinical picture, but was associated with limited improvement, presumably a result of irreversible injury to the spinal cord by the syrinx.…”

Section: Discussionmentioning

confidence: 58%

Elucidating the pathophysiology of syringomyelia

Heiss

Patronas²,

DeVroom³

et al. 1999

FOC

147

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Object Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy. Methods The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, cervical subarachnoid, and lumbar intrathecal spaces and syrinx. Six months after surgery, clinical examinations, MR imaging studies, and CSF pressure recordings were repeated. Clinical examinations and MR imaging studies were repeated annually. For comparison, 18 healthy volunteers underwent T1-weighted MR imaging, cine MR imaging, and cervical and lumbar subarachnoid pressure testing. Compared with healthy volunteers, before surgery, the patients had decreased anteroposterior diameters of the ventral and dorsal CSF spaces at the foramen magnum. In patients, CSF velocity at the foramen magnum was increased, but CSF flow was reduced. Transmission of intracranial pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was partially obstructed. Spinal CSF compliance was reduced, whereas cervical subarachnoid pressure and pulse pressure were increased. Syrinx fluid flowed inferiorly during systole and superiorly during diastole on cine MR imaging. At surgery, the cerebellar tonsils abruptly descended during systole and ascended during diastole, and the upper pole of the syrinx contracted in a manner synchronous with tonsillar descent and with the peak systolic cervical subarachnoid pressure wave. Following surgery, the diameter of the CSF passages at the foramen magnum increased compared with preoperative values, and the maximum flow rate of CSF across the foramen magnum during systole increased. Transmission of pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was normal and cervical subarachnoid mean pressuree and pulse pressure decreased to normal. The maximum syrinx diameter decreased on MR imaging in all patients. Cine MR imaging documented reduced velocity and flow of the syrinx fluid. Clinical symptoms and signs improved or remained stable in all patients, and the tonsils resumed a normal shape. Conclusions The progression of syringomyelia associated with Chiari I malformation is produced by the action of the cerebellar tonsils, which partially occlude the subarachnoid space at the foramen magnum and act as a piston on the partially enclosed spinal subarachnoid space. This creates enlarged cervical subarachnoid pressure waves that compress the spinal cord from without, not from within, and propagate syrinx fluid caudally with each heartbeat, which leads to syrinx progression. The disappearance of the abnormal shape and position of the tonsils after simple decompressive extraarachnoidal surgery suggests that the Chiari I malformation of the cerebellar tonsils is acquired, not congenital. Surgery limited to suboccipital craniectomy, C-1 laminectomy, and duraplasty eliminates this mechanism and eliminates syringomyelia and its progression without the risk of more invasive procedures.

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“…Summary scores (PCS, MCS, SDI) were independent of surgical or conservative treatment, supporting the findings by Boiardi and colleagues, who noted no significant difference in the clinical progress of patients with syringomyelia who underwent surgical intervention compared to those who did not. 9 These results should guide us to utilize invasive treatments only if neurological deterioration occurs, as any intervention can aggravate a patient's complaints.…”

Section: Discussionmentioning

confidence: 98%