Endoscopic fenestration of posterior fossa arachnoid cyst for the treatment of presyrinx myelopathy--case report

A 32-year-old man presented with an arachnoid cyst of the posterior fossa manifesting as cervical syringomyelic myelopathy. Magnetic resonance (MR) imaging demonstrated edematous enlargement and T2 prolongation of the cervical spinal cord, indicating a "presyrinx" state. MR imaging showed the inferior wall of the cyst, which disturbed cerebrospinal fluid (CSF) pulsatile movement between the intraspinal and intracranial subarachnoid spaces. The cyst wall was fenestrated with a neuroendoscope. The presyrinx state and the CSF movement improved. Posterior fossa arachnoid cyst, as well as Chiari malformation, can cause CSF flow disturbance at the craniocervical junction and syringomyelia. Endoscopic fenestration is less invasive than foramen magnum decompression and should be the procedure of choice.     

Circumferential decompression of the foramen magnum for the treatment of syringomyelia associated with basilar invagination

Posterior fossa decompression utilizing suboccipital craniectomy and duraplasty remains the standard surgical treatment for Chiari-associated syringomyelia. In the presence of basilar invagination, anterior decompression, typically transoral odontoidectomy, or posterior decompression may be performed. We report two cases in which anterior and posterior (circumferential) decompression of the foramen magnum was used to treat cervical syringomyelia successfully. These cases demonstrate that circumferential decompression of the foramen magnum may be necessary in some cases of cervical syringomyelia associated with basilar invagination and Chiari malformation.     

Repair of Chiari III malformation using cranioplasty and an occipital rotation flap: technical note and review of literature

Background

Chiari III malformation (CM3) is rare among Chiari malformations (I-IV). Its definition has been expanded to include caudal medullary displacement and hindbrain herniation into encephaloceles in lower occipital and high cervical regions. Prognosis is recorded as dismal, with respect to survival and functional outcome.

Methods

We describe the presentation, radiologic evaluation, and repair of this malformation using methyl-methacrylate cranioplasty and an occipital scalp rotation flap for closure. Outcome after surgery is addressed.

Results

Adequate closure of the defect and protection of underlying structures was achieved without undue stress at incision site.

Conclusions

This method of closure can be considered in cases of large occipital and cervical encephaloceles with poor skin cover and added osseous anomalies around the foramen magnum.     

Retrocerebellar arachnoid cyst resulting in syringomyelia in a patient without tonsillar herniation: successful surgical treatment with reconstruction of CSF flow in the foramen magnum region

A retrocerebellar arachnoid cyst causing syringomyelia is extremely rare without tonsillar herniation. The authors present a 44-year-old woman with symptoms of foramen magnum compression and syringomyelia. Magnetic resonance imaging demonstrated a large retrocerebellar arachnoid cyst with a large cervicothoracic syrinx but no signs of tonsillar herniation or hydrocephalus. The patient underwent a foramen magnum decompression with C1 laminectomy, microsurgical fenestration of the cyst, and duraplasty. After successful reconstruction of CSF flow, the patient experienced a relief of symptoms and a significant reduction of the syrinx. The intraoperative findings support the theory of a piston mechanism in the development of syringomyelia. Additional arachnoidal adhesions may also obstruct the CSF flow around the craniocervical junction. We recommend the surgical treatment should consist of an adequate decompression of the foramen magnum, wide microsurgical arachnoidal debridement, and duraplasty with autologous grafts sutured in a watertight way.     

Surgical treatment of syringomyelia. Selection of surgical procedures

The surgical approach to syringomyelia is controversial. In this study, the authors evaluated the results of various operative procedures applied in 31 patients with syringomyelia. Syringomyelia was associated with Chiari malformation in 17 cases, with spinal adhesive arachnoiditis in nine, with trauma in three, and with epidural arachnoid cyst in one. One case was idiopathic. A total of 38 operations were performed. Syringosubarachnoid shunting was applied in 17 patients, syringoperitoneal shunting in 11, terminal syringostomy in three, ventriculoperitoneal shunting in three, lumboperitoneal shunting in two, foramen magnum decompression (suboccipital craniectomy plus upper cervical laminectomy) and terminal syringostomy in one, and foramen magnum decompression with syringosubarachnoid shunting in one. The postoperative follow-up period ranged from 2 to 55 months (average, 26 months). Of the 31 patients, 23 showed neurological improvement, five were unchanged, and three deteriorated. Among the last three, one patient with Chiari malformation developed shunt malfunction due to arachnoiditis after syringosubarachnoid shunting. In two patients with syringomyelia secondary to adhesive arachnoiditis, the spinal cord was damaged by extensive separation of the arachnoid membrane at surgery. On the basis of the results in these 31 cases, the authors conclude that syringosubarachnoid shunting is effective for syringomyelia associated with Chiari malformation if syringomyelia is responsible for the clinical symptoms. Post-traumatic syringomyelia and syringomyelia secondary to adhesive arachnoiditis should be treated by syringoperitoneal shunting. If hydrocephalus is present, ventriculoperitoneal shunting is indicated. Finally, terminal syringostomy is no more effective than syringosubarachnoid or syringoperitoneal shunting.     

Foramen magnum decompression for syringomyelia associated with basilar impression and Chiari I malformation--report of three cases.

Anterior or posterior decompression of the foramen magnum was performed in three patients with syringomyelia associated with basilar impression and Chiari I malformation. The operative results were evaluated using the pre- and postoperative magnetic resonance (MR) images. Two patients with combined anterior and posterior cervicomedullary compression due to basilar impression and tonsillar descent received suboccipital craniectomy, upper cervical laminectomy, and dural plasty without any intradural manipulations via the posterior approach. One patient with prominent anterior cervicomedullary compression due to basilar impression and a sharp clivoaxial angle was operated on by the transoral anterior approach. Postoperatively, all patients showed a sustained shrinkage of the syrinx and rounding of the flattened cerebellar tonsils. Two patients showed upward movement of the herniated tonsils. All patients had improved symptoms during 2-4 years follow-up. Treatment of syringomyelia associated with basilar impression and Chiari I malformation requires more efficient decompressive procedures at the foramen magnum based on neurological and MR findings.     

枕颈部畸形合并颈脊髓空洞症的外科治疗

报告８例枕颈部畸形合并颈脊髓空洞症（Ｃｈｉａｒｉ畸形Ａ型）并经手术治疗。根据临床表现和影像学（ＭＲＩ）征象，应用枕骨大孔扩大，寰椎后弓切除减压，枕颈自体髂骨植骨融合及脊髓空洞蛛网膜下腔分流术。术后症状和体征明显改善７例，无变化１例。本文对有临床症状的Ｃｈｉａｒｉ畸形的发病和治疗进行了讨论．     

Clinical and radiological outcome of craniocervical osteo-dural decompression for Chiari I-associated syringomyelia

The aim of this study was to analyze the long-term clinical and radiological outcomes of craniocervical decompression for patients affected by Chiari I-related syringomyelia. We performed a retrospective analysis of a group of patients affected by Chiari I-associated syringomyelia treated by craniocervical decompression (CCD). Surgical and technical aspects and preoperative factors predicting outcome were discussed. A total of 36 patients were reviewed. There were 17 men and 19 women (female/male ratio 1.11), and the mean age was 40.4 (range 18–68). The most important preoperative symptoms were related to myelopathy (pain, weakness, atrophy, spasticity, sensory loss, and dysesthesias). Most syrinxes were in the cervico-thoracic region (61.1%), and the majority of patients had tonsillar descent between the foramen magnum and C1. All patients underwent a craniectomy less than 3 cm in diameter followed by a duroplasty with dura substitute. No arachnoid manipulation was necessary. Three patients (8.1%) experienced cerebrospinal fluid leaks that resolved without complications. At a mean follow up of 40 months (range 16–72) 80.5% of patients exhibited improvement over their preoperative neurological examination while 11.1% stabilized. The syrinx shrank in 80.5% of patients. Chi-square test showed that preoperative syrinx extension and degree of tonsillar descent did not correlate with clinical and neuroradiological postoperative evolution. Treating syringomyelia associated in Chiari I malformation with CCD leads to a large percentage of patients with satisfying results and no irreversible complications.     

Foramen magnum decompression for the treatment of Arnold Chiari malformation type I with associated syringomyelia in an elderly patient

STUDY DESIGN: Report of a rare case of an elderly patient with late onset of Arnold Chiari malformation type I with associated syringomyelia that was successfully treated with foramen magnum decompression. OBJECTIVE: To report this rare case along with a literature review. SETTING: Gifu, Japan. METHODS: A 69-year-old woman with a 4-year history of dull pain in her right arm was referred to the clinic. After physical and radiographical examinations, she was diagnosed with Arnold Chiari malformation type I with associated syringomyelia. A foramen magnum decompression by the removal of the outer layer of the dura mater was performed. RESULTS: At 2 years postoperatively, MRI revealed a decrease in the size of the syringomyelia. Her symptoms had also remarkably improved. CONCLUSIONS: A rare case of symptomatic Arnold Chiari malformation type I with associated syringomyelia in an elderly woman was successfully treated with foramen magnum decompression by the removal of the outer layer of the dura mater.     

Anterior atlas fracture following suboccipital decompression for Chiari I malformation. Report of two cases

Chiari I malformation, a congenital disorder involving downward displacement of the cerebellar tonsils through the foramen magnum, is often treated surgically by performing suboccipital craniectomy and C-1 laminectomy. The authors report two cases in which fracture of the anterior atlantal arch occurred during the postoperative period following Chiari I decompression and C-1 laminectomy causing significant neck pain. The findings indicate that interruption of the integrity of the posterior arch of C-1, iatrogenically or otherwise, confers increased risk of anterior arch fracture. A C-1 fracture should therefore be considered in the differential diagnosis of posterior cervical pain in patients who have previously undergone decompression for Chiari I malformation.     

Spontaneous resolution of Chiari I malformation and syringomyelia: case report and review of the literature

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.     

“Triple R” tonsillar technique for the management of adult Chiari I malformation: surgical note

Background

Chiari type I malformation is a congenital disorder that is characterized by the caudal extension of the cerebellar tonsils through the foramen magnum into the cervical canal and by a reduced posterior fossa volume.

Methods

We report our surgical technique of reposition, reduction, or resection of the cerebellar tonsils for the management of Chiari I malformation. The procedure was performed in 22 adult patients, in three different centers, with a mean age of 37 years. Clinical complaints included headaches, nuchalgia, vertigo, and upper-limb weakness or numbness. Seven patients had cervical syringomyelia. Symptoms developed within a mean time of 36 months (range, 12–70 months).

Results

The cerebellar tonsils were exposed through a dura mater–arachnoid incision at the atlanto-occipital space after a 0.5-cm rimming craniectomy of the occipital bone in all patients. In seven patients the tonsils were resected, in other seven were reduced by subpial coagulation and aspiration, and in the remaining eight patients the tonsils were repositioned after coagulating their surfaces. Three patients had also a posterior fossa arachnoid cyst that was fenestrated in two of them. All patients improved postoperatively. Syringomyelia was reduced in five of seven patients. The mean length of the follow-up period was 12 months.

Conclusions

Selective reposition, reduction, or resection of herniated cerebellar tonsils may improve symptoms in adult patients with Chiari I malformation.     

Surgical outcomes of foramen magnum decompression for syringomyelia associated with Chiari I malformation: relation between the location of the syrinx and body pain

Background  

There have been few reports about the relation between the morphology of syrinxes and body pain in syringomyelia associated with Chiari I malformation. To investigate this phenomenon, the relation between the location of the syrinx and body pain before and after foramen magnum decompression (FMD) were evaluated.     

Chiari malformation (type I) associated with bilateral abducens nerve palsy: case report

There are still many questions concerning the pathology and therapeutic strategy for Chiari malformation. We recently encountered a case of Chiari malformation associated with only bilateral abducens nerve palsy which was successfully treated by foramen magnum decompression. The pathology and mechanisms of Chiari malformation (type I) were evaluated in this case. The patient was a 12-year-old girl who had visited our institute 1 month previously complaining of diplopia. She had no particular past or family history and her general appearance was also normal. Bilateral abducens nerve palsy was the only neurological deficit. Her cerebrospinal pressure was 9 cm H2O. Neuroradiological findings revealed basilar impression, C4-6 syringomyelia and Chiari malformation (type I), but no hydrocephalus or meningocele. Foramen magnum decompression with lateral extension, upper cervical laminectomy and open duraplasty were performed. The position of both eyes recovered fully shortly after surgery, and diplopia occurred only when the patient looked sideways. Eye movements also returned completely to normal 3 months after surgery. MRI showed no syringomyelia 4 months after surgery, the upward shift of the pendulous portion of the cerebellar tonsil, and the expansion of the subarachnoidal space of the pons-oblongata junction. In conclusion, it was thought that the mechanism of bilateral abducens nerve palsy in this case was due to the strangulation and the downward traction of the pons-oblongata junction. The nerve was relieved from this traction by foramen magnum decompression.     

枕颈畸形和脊髓空洞症及其外科治疗

本文报告１３例颈枕部畸形合并脊髓空洞症。根据临床表现和影象学征象，设计并实施外科治疗。其外科基本操作过程：枕骨大孔扩大，寰椎后弓切除减压及枕骨和第二颈椎棘突基底部植骨融合术，脊髓空洞与蛛网膜下腔分流术，平均随访２５个月。其结果：症状和体征明显改善１０例，稍改善１例，无变化１例，因呼吸衰竭死亡１例。本文对枕颈畸形合并脊髓空洞症及其治疗方法作了讨论。     

Hiccups attributable to syringobulbia and/or syringomyelia associated with a Chiari I malformation: case report

OBJECTIVE AND IMPORTANCE: Approximately 20 to 50% of patients with syringomyelia associated with Chiari malformations exhibit cranial nerve or cerebellar symptoms. However, hiccups represent a rare clinical manifestation of this disorder. We report a case of intractable hiccups resulting from syringobulbia associated with a Chiari I malformation, which was successfully treated with foramen magnum decompression. CLINICAL PRESENTATION: We report the case of a patient who presented with syringomyelia and syringobulbia associated with a Chiari I malformation, manifested as intractable hiccups and neurological deficits. Magnetic resonance imaging scans demonstrated syringobulbia in the dorsal medullary region and a large cervical syrinx from C2 to C6-C7, associated with a Chiari I malformation. INTERVENTION: Foramen magnum decompression and a C1 laminectomy were performed. One month later, the intractable hiccups disappeared and the neurological symptoms demonstrated improvement. CONCLUSION: Postoperative magnetic resonance imaging scans demonstrated enlargement of the subarachnoid space in the posterior fossa and disappearance of the syringobulbia. There has been no recurrence of intractable hiccups and syringobulbia in 6 months after surgery. Magnetic resonance imaging of the brainstem is an important diagnostic procedure for intractable hiccups, because syringobulbia associated with a Chiari malformation represents a surgically treatable disorder, although the incidence is low.     

Acute presentations of syringomyelia. Report of three cases

Three unusual cases are reported in which communicating syringomyelia presented acutely. The first patient presented with paraplegia, the second with acute respiratory distress secondary to bilateral vocal cord paralysis, and the third with symptoms of acute brain-stem ischemia. Each patient had a communicating spinal cord syrinx associated with a posterior fossa and foramen magnum region anomaly (a huge posterior fossa arachnoid cyst in one and Chiari malformations in two). The mechanisms of craniospinal pressure dissociation and hindbrain herniation are discussed, along with other reported emergency presentations of syringomyelia.     

Malformations of the craniocervical junction (chiari type I and syringomyelia: classification,diagnosis and treatment)

Chiari disease (or malformation) is in general a congenital condition characterized by an anatomic defect of the base of the skull, in which the cerebellum and brain stem herniate through the foramen magnum into the cervical spinal canal. The onset of Chiari syndrome symptoms usually occurs in the second or third decade (age 25 to 45 years). Symptoms may vary between periods of exacerbation and remission. The diagnosis of Chiari type I malformation in patients with or without symptoms is established with neuroimaging techniques. The most effective therapy for patients with Chiari type I malformation/syringomyelia is surgical decompression of the foramen magnum, however there are non-surgical therapy to relieve neurophatic pain: either pharmacological and non-pharmacological. Pharmacological therapy use drugs that act on different components of pain. Non-pharmacological therapies are primarly based on spinal or peripheral electrical stimulation.     

Advanced Chiari malformation type I with marked spinal cord atrophy. Case report

The authors discuss the results obtained in patients who underwent foramen magnum decompression for longstanding advanced Chiari I malformation in which marked spinal cord atrophy was present. This 50-year-old woman presented with progressive quadriparesis and sensory disorders. Magnetic resonance imaging revealed the descent of cerebellar tonsils and medulla associated with remarkable C1-L2 spinal cord atrophy. After a C-1 laminectomy-based foramen magnum decompression, arachnoid dissection and duraplasty were undertaken. These procedures resulted in remarkable neurological improvement, even after 40 years of clinical progression. Spinal cord atrophy may be caused by chronic pressure of entrapped cerebrospinal fluid in the spinal canal.