Ken Sakushima, Satoshi Tsuboi, Ichiro Yabe, Kazutoshi Hida, Satoshi Terae, Ritei Uehara, Imaharu Nakano, Hidenao Sasaki
Nationwide survey on the epidemiology of syringomyelia in Japan.
J Neurol Sci. 2012 Feb 15;313(1-2):147-52. doi: 10.1016/j.jns.2011.08.045. Epub 2011 Sep 25.
Abstract/Text
BACKGROUND: Syringomyelia is a rare disease characterized by abnormal fluid-filled cavities within the spinal cord, and is associated with Chiari malformations, arachnoiditis, or spinal cord tumors. The widespread availability of magnetic resonance imaging (MRI) in Japan has allowed for easy identification of syrinxes. The aim of this study was to survey the clinicoepidemiological characteristics of syringomyelia in Japan.
METHODS: A 2-stage postal survey was conducted in late 2009. The first survey aimed to estimate the number of patients with syringomyelia, and the second survey aimed to elucidate clinicoepidemiological characteristics. Diagnosis of syringomyelia was based on the findings of MRI or computed tomographic myelography.
RESULTS: In the first survey, we received 2133 responses from 2937 randomly selected departments and collected data of 1215 syringomyelia patients (543 men and 672 women). The total response rate for the first survey was 73%. The estimated prevalence of ambulatory syringomyelia patients in Japan was 1.94 per 100000. In the second survey, the proportion of asymptomatic syringomyelia patients was 22.7%. Chiari type I malformations and idiopathic syringomyelia were the first and second most common etiologies.
CONCLUSIONS: Our nationwide survey indicated that widespread MRI availability has contributed to the diagnosis of both asymptomatic and idiopathic cases.
Copyright © 2011 Elsevier B.V. All rights reserved.
庄司寛和、伊藤拓緯、平野徹 ほか: 大孔減圧術後に改善した脊髄空洞症、キアリ奇形に伴う脊柱側弯症の1例. 新潟整外研会誌25: 29-32, 2009.
T Isu, H Sasaki, H Takamura, N Kobayashi
Foramen magnum decompression with removal of the outer layer of the dura as treatment for syringomyelia occurring with Chiari I malformation.
Neurosurgery. 1993 Nov;33(5):845-9; discussion 849-50.
Abstract/Text
The surgical results of foramen magnum decompression in seven patients with syringomyelia associated with Chiari I malformations are reported. The patients were two men and five women, ranging in age from 23 to 54 years (mean, 30 yr). A bony foramen magnum decompression combined with the removal of the outer layer of the dura mater was performed in seven patients. In an average postoperative follow-up period of 2 years (range, 1-3 yr), neurological symptoms and signs improved in six of seven patients and were unchanged in one patient. Postoperative magnetic resonance imaging scans taken a few weeks after surgery showed a decrease in the size of the syrinx or a disappearance of the syrinx in five of seven patients; a few months were required for a similar reduction in the remaining two patients. In all seven patients, the decompression of the foramen magnum proved to be sufficient, as disclosed by postoperative magnetic resonance imaging. Foramen magnum decompression by our surgical technique is advantageous because all the procedures are extradural and there are, therefore, fewer postoperative complications than the foramen magnum decompression techniques previously reported. Foramen magnum decompression by the authors' surgical technique is effective as the initial surgical treatment for syringomyelia associated with Chiari I malformations.
Alex Alfieri, Giampietro Pinna
Long-term results after posterior fossa decompression in syringomyelia with adult Chiari Type I malformation.
J Neurosurg Spine. 2012 Nov;17(5):381-7. doi: 10.3171/2012.7.SPINE12272. Epub 2012 Aug 31.
Abstract/Text
OBJECT: There is little information about the long-term effectiveness and complications following decompressive surgery for syringomyelia related to Chiari malformation Type I (CM-I).
METHODS: Examining long-term clinical and radiological follow-up, the authors studied a mixed retrospective and prospective single-institution cohort of 109 consecutive surgically treated adult patients with syringomyelia and CM-I. All patients underwent a standardized surgical protocol: decompression of the craniocervical junction, arachnoid exploration, and shrinkage of the cerebellar tonsils. Factors predicting outcome were investigated.
RESULTS: The retrospective arm consisted of 41 cases treated between 1990 and 1994, and the prospective arm comprised 68 patients treated between 1994 and 2001. The mean overall age was 45.9 years, and 58.8% of the population was female. The median follow-up period was 12.7 years. The most frequent initial symptoms were pain and sensory and gait disturbances. There was no perioperative death or neurological deterioration. The comprehensive perioperative complication rate was approximately 11%, with 3 cases (2.7%) of CSF leakage. Regression analysis showed that the best combination of clinical and radiological outcome predictors was age and duration of symptoms. Clinical follow-up confirmed surgical result stability with clinical improvement of greater than 90% of the spinal and cranial manifestations over a long-term period. Two patients had radiological recurrences of syringomyelia without clinical signs 85 and 124 months after surgery.
CONCLUSIONS: Certain clinical predictors of poor clinical and radiological prognosis were identified-namely, age at time of surgery and symptom duration. The results of the study provide additional long-term data that support the effectiveness and safety of relieving CSF block at the craniocervical junction in CM-I-related syringomyelia.
Christopher M Bonfield, Allan D Levi, Paul M Arnold, David O Okonkwo
Surgical management of post-traumatic syringomyelia.
Spine (Phila Pa 1976). 2010 Oct 1;35(21 Suppl):S245-58. doi: 10.1097/BRS.0b013e3181f32e9c.
Abstract/Text
STUDY DESIGN: Systematic review.
OBJECTIVE: To determine the indications for surgical intervention and optimal surgical treatment technique for patients with post-traumatic syringomyelia and spinal cord tethering.
SUMMARY OF BACKGROUND DATA: The proper management strategy for post-traumatic syringomyelia has not been established. Most modern surgical series have documented improvement in symptomatic patients who have an internal decompression of their syrinx. Several options exist and include shunting the syrinx (to the subarachnoid space or to either the pleural or peritoneal cavities) as well as spinal cord untethering (with or without expansile duraplasty).
METHODS: A systematic review of literature followed by expert panel consensus was performed. English language literature published between 1980 and 2010 was gathered to examine articles search was conducted using the search terms syringomyelia, syrinx, spinal cord injury, traumatic syringomyelia, post-traumatic syringomyelia. Case reports and articles examining syrinx due to other cause were excluded. Articles were graded for strength of evidence according to the GRADE approach. The evidentiary tables were reviewed and approved by all 4 authors, and disagreements were resolved by consensus.
RESULTS: The literature search yielded a total of 296 abstracts, and 22 articles were found to fulfill all the criteria specified above. All identified articles were of low or very low evidence levels. The reported incidence of post-traumatic syringomyelia is 0.5% to 4.5%; the incidence is twice as common in complete versus incomplete injuries. The literature consistently demonstrated that surgery post-traumatic syringomyelia is effective at arresting or improving motor deterioration, but not sensory dysfunction or pain syndromes. The literature does not support surgical intervention for incidental, asymptomatic syrinx. The literature does not support one surgical technique as superior for the treatment of post-traumatic syringomyelia.
CONCLUSION: The literature supports and the consensus panel recommended that there is no indication for direct decompression at the time of initial injury specifically for the purpose of limiting future risk of syringomyelia. The literature supports and the consensus panel gave a strong recommendation for surgical intervention in the setting of motor neurologic deterioration as a consequence of post-traumatic syrinx/tethered cord. The panel gave a weak recommendation against surgical intervention for patients developing sensory loss/pain syndrome or for asymptomatic but expanding syrinx. Finally, the literature does not provide strong evidence to support the superiority of one surgical technique over the others; however, the consensus panel gave a weak recommendation that spinal cord untethering with expansile duraplasty is the preferred first-line surgical technique.
Jörg Klekamp
Treatment of syringomyelia related to nontraumatic arachnoid pathologies of the spinal canal.
Neurosurgery. 2013 Mar;72(3):376-89; discussion 389. doi: 10.1227/NEU.0b013e31827fcc8f.
Abstract/Text
BACKGROUND: Disturbances of cerebrospinal fluid (CSF) flow are the commonest cause of syringomyelia. Spinal arachnopathies may lead to CSF flow obstructions but are difficult to diagnose. Consequently, associated syringomyelias are often categorized as idiopathic.
OBJECTIVE: To present and analyze the diagnosis of and long-term outcomes in an observational study of patients with nontraumatic arachnopathies from 1991 to 2011.
METHODS: A total of288 patients (mean age, 47 ± 15 years; follow-up, 54 ± 46 months) were evaluated. Decompression with arachnolysis, untethering, and duraplasty for restoration of CSF flow was recommended to patients with neurological progression. Neurological examinations, magnetic resonance images, and follow-up data were evaluated. Individual symptoms were analyzed during the first postoperative year, and long-term outcomes were analyzed with Kaplan-Meier statistics to determine rates of progression-free survival.
RESULTS: In total,189 patients either refused an operation or were managed conservatively for lack of progression. Among 79 unoperated patients with follow-up information available for up to 8 years, 2 patients deteriorated. Ninety-nine patients with progressive symptoms underwent 116 operations: 108 decompressions and 8 other surgeries. Three months postoperatively, 53% considered their status improved and 37% were unchanged. In the long term, surgery on arachnopathies limited to 2 spinal segments was followed by progression-free survival for 78% over 10 years, in contrast to 31% with extensive arachnopathies.
CONCLUSION: Surgery on nontraumatic arachnopathies related to syringomyelia should be reserved for patients with progressive symptoms. Arachnolysis, untethering, and duraplasty provide good long-term results for focal arachnopathies. For extensive pathologies with a history of subarachnoid hemorrhage or meningitis, treatment remains a major challenge.
Benedetta Ludovica Pettorini, Anna Gao, Desiderio Rodrigues
Acute deterioration of a Chiari I malformation: an uncommon neurosurgical emergency.
Childs Nerv Syst. 2011 Jun;27(6):857-60. doi: 10.1007/s00381-011-1442-9. Epub 2011 Apr 7.
Abstract/Text
OBJECTIVES: Report and discuss acute neurological deterioration of Chiari I malformation (CMI), surgical treatment and timing, clinical outcome and literature review.
CASE REPORT: We report a recent case of a 15-year-old girl admitted for an acute neurological deterioration caused by an undiagnosed hindbrain herniation that required an urgent foramen magnum decompression and external ventricular drainage insertion. Moreover, we report and discuss the literature. To the authors' knowledge, this is only the third paediatric patient identified in this setting to be treated for an acute neurological deterioration due to a previous asymptomatic hindbrain herniation. The patient made an uncomplicated recovery and was discharged home on the seventh postoperative day and has remained well at review.
DISCUSSION: Acute deterioration of CMI in completely asymptomatic patients in absence of concomitant pathological findings is rarely reported in the literature, and exceptional in children.
CONCLUSIONS: CMI is typically treated electively, but as this case illustrates, it can present with rapidly deteriorating neurological signs. Symptoms usually respond well to surgical intervention with rapid improvement.
Jennifer Strahle, Karin M Muraszko, Joseph Kapurch, J Rajiv Bapuraj, Hugh J L Garton, Cormac O Maher
Natural history of Chiari malformation Type I following decision for conservative treatment.
J Neurosurg Pediatr. 2011 Aug;8(2):214-21. doi: 10.3171/2011.5.PEDS1122.
Abstract/Text
OBJECT: The natural history of the Chiari malformation Type I (CM-I) is incompletely understood. The authors report on the outcome of a large group of patients with CM-I that were initially selected for nonsurgical management.
METHODS: The authors identified 147 patients in whom CM-I was diagnosed on MR imaging, who were not offered surgery at the time of diagnosis, and in whom at least 1 year of clinical and MR imaging follow-up was available after the initial CM-I diagnosis. These patients were included in an outcome analysis.
RESULTS: Patients were followed clinically and by MR imaging for a mean duration of 4.6 and 3.8 years, respectively. Of the 147 patients, 9 had new symptoms attributed to the CM-I during the follow-up interval. During this time, development of a spinal cord syrinx occurred in 8 patients; 5 of these patients had a prior diagnosis of a presyrinx state or a dilated central canal. Spontaneous resolution of a syrinx occurred in 3 patients. Multiple CSF flow studies were obtained in 74 patients. Of these patients, 23 had improvement in CSF flow, 39 had no change, and 12 showed worsening CSF flow at the foramen magnum. There was no significant change in the mean amount of cerebellar tonsillar herniation over the follow-up period. Fourteen patients underwent surgical treatment for CM-I. There were no differences in initial cerebellar tonsillar herniation or CSF flow at the foramen magnum in those who ultimately underwent surgery compared with those who did not.
CONCLUSIONS: In patients with CM-Is that are selected for nonsurgical management, the natural history is usually benign, although spontaneous improvement and worsening are occasionally seen.
J Klekamp, G Iaconetta, M Samii
Spontaneous resolution of Chiari I malformation and syringomyelia: case report and review of the literature.
Neurosurgery. 2001 Mar;48(3):664-7.
Abstract/Text
OBJECTIVE AND IMPORTANCE: Indications for surgery and the surgical technique of foramen magnum decompression for patients with Chiari I malformation and syringomyelia are controversial issues. This case report supports the view that observation may be adequate for patients without progressive symptoms or with mild clinical symptoms.
CLINICAL PRESENTATION: A 37-year-old woman presented with a 3-month history of burning dysesthesias and hypesthesia in her right arm. A neurological examination revealed hypesthesia in the right trigeminal distribution. A magnetic resonance imaging scan revealed a Chiari I malformation with syringomyelia between C2 and T2. No hydrocephalus was observed.
CLINICAL COURSE: Because the patient's symptoms regressed spontaneously, surgery was not performed. Thirty-two months after her initial examination, the patient was asymptomatic. A second magnetic resonance imaging scan was obtained, which demonstrated complete spontaneous resolution of the Chiari I malformation and syringomyelia.
CONCLUSION: We attribute the regression of the patient's symptoms to spontaneous recanalization of cerebrospinal fluid pathways at the foramen magnum, which most likely was due to rupture of the arachnoid membranes that had obstructed cerebrospinal fluid flow.
Mario Cardoso, Robert F Keating
Neurosurgical management of spinal dysraphism and neurogenic scoliosis.
Spine (Phila Pa 1976). 2009 Aug 1;34(17):1775-82. doi: 10.1097/BRS.0b013e3181b07914.
Abstract/Text
STUDY DESIGN: To review diagnosis and treatment of neurogenic factors implicated in the development of progressive scoliosis.
OBJECTIVE: Increased awareness of neurogenic causes as a contributing component of spinal cord tethering has led to enhanced radiographic surveillance for etiologic factors contributing to the genesis of scoliosis. Review of various manifestations of spinal dysraphism offers better definition of clinical indications for surveillance MRI scans and thus may contribute to improving outcomes for affected individuals.
SUMMARY OF BACKGROUND DATA: Increasing utilization of surveillance MRI has led to a greater awareness of neurogenic causes as contributing factors in the setting of scoliosis. It is imperative for clinicians treating individuals with scoliosis to be aware of the most common etiologies of neurogenic factors as well as be cognizant of the neurosurgical approaches to treating these conditions in a pre-emptive fashion. This will serve to minimize potential neurological complications and offer improved surgical outcomes after instrumentation.
METHODS: Current therapeutic approaches were outlined for various etiologies of neurogenic scoliosis as well as neurosurgical management of the tethered cord, spinal cord tumors in addition to current challenges surrounding Chiari malformations and syringomyelia.
RESULTS: Timely recognition of these frequently progressive conditions may not only prevent irreversible neurologic compromise but may also help to ameliorate or stabilize concurrent scoliosis. Tethered cords are best treated by releasing the affected cord and offers the best opportunity to stabilize or improve the scoliosis. Syringomyelia, often associated with a Chiari malformation, is a well-known progenitor of scoliosis, and addressing the underlying cause with a Chiari decompression frequently leads to a reduction or resolution of the syrinx and may result in a concomitant improvement in scoliosis.
CONCLUSION: Surveillance MRI should be undertaken for scoliosis when there are clinical indications consistent for a tethered cord, spinal cord tumor, or Chiari malformation and associated syringomyelia.
日本ペインクリニック学会編：神経障害性疼痛薬物療法ガイドライン（改訂第2版）2016、真興交易 医書出版部、2016.
Robert J Rothrock, Victor M Lu, Allan D Levi
Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting.
J Neurosurg Spine. 2021 Jul 30;35(4):535-545. doi: 10.3171/2020.12.SPINE201826. Epub 2021 Jul 30.
Abstract/Text
OBJECTIVE: Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities.
METHODS: Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement.
RESULTS: A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts.
CONCLUSIONS: The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.
K Ohata, T Gotoh, Y Matsusaka, M Morino, N Tsuyuguchi, B Sheikh, Y Inoue, A Hakuba
Surgical management of syringomyelia associated with spinal adhesive arachnoiditis.
J Clin Neurosci. 2001 Jan;8(1):40-2. doi: 10.1054/jocn.2000.0731.
Abstract/Text
The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.
