Spontaneous resolution of a Chiari I malformation associated syringomyelia in one child

Summary A child with complete spontaneous resolution of a Chiari I malformation associated Syringomyelia without surgical intervention is presented. The child was followed clinically by serial magnetic resonance imaging (MRI) and remains neurologically stable after 8-years of follow-up. To our knowledge, only 6 pediatric cases with spontaneous resolution of a spinal cord syrinx documented by MRI without surgical intervention have been reported. This case is of interest in the light of the postulated theories to explain spontaneous resolution of syringomyelia.     

Spontaneous resolution of syringomyelia without Chiari malformation

A 30-year-old woman presented with a cervical syrinx manifesting as hemihypesthesia. Neuroimaging found no evidence of Chiari malformation or tight cisterna magna. Serial magnetic resonance imaging studies over a 6-year period demonstrated spontaneous and complete resolution of the syrinx accompanied by an asymptomatic clinical course. The natural history of syringomyelia is highly unpredictable. The outcome of surgical treatment for patients with syringomyelia is not always satisfactory, so the indications for surgery are controversial. Spontaneous resolution of syringomyelia unrelated with foramen magnum lesion has various causes. Close follow up of the patient is necessary to monitor for recurrence.     

14 cases of communicating syringomyelia associated with Chiari I malformation in children]

The authors review their experience of 14 children with syringomyelia and associated Chiari I malformation observed during the last 21 years. Initial symptoms were motor weakness (57%), sensory signs (50%), scoliosis (50%) and bladder dysfunction (21.5%), while signs of admission were pyramidal signs (78.5%) with motor deficit (43%), spinal deformities (64.2%), syringomyelic syndrome (36%) and sensory deficit (21.5%). Four children were investigated with myelography, three with myelography and spinal CT Scan and the last seven cases with MRI. Ten children (71.4%) underwent a decompression of the Chiari malformation with or without drainage of the cyst and shunting of an associated hydrocephalus. Syringo-peritoneal shunts were used in 3 children and laminectomy with syringo-subarachnoid shunt in 1 case. The neurological symptoms improved in 57% of the cases, 2 patients deteriorated and 4 patients were lost to follow-up. The authors discuss the clinical symptomatology, the MRI study, the controversies concerning the treatment and concluded with their attitude concerning this pathology in children.     

Surgical technique for cranio-cervical decompression in syringomyelia associated with Chiari type I malformation

Summary Our purpose is to present our results with the surgical treatment of syringomyelia associated with Chiari type I malformation. Between October 1989 and October 1995, twenty-eight patients underwent a sub-occipital craniotomy and a C₁ laminectomy. After dura mater opening the cerebellar tonsils were mobilised. Neither catheter, nor plugging of the obex, nor tonsillar tissue removal was performed. The dura mater was enlarged by means of a wide graft to create a newcisterna magna of adequate size. Postoperative MRI scans showed an ascent of the cerebellum of 4.3±4.8 mm (measured by thefastigium to basal line), as well as of the brainstem (mean migration of the mesencephalon-pons junction of 4.3±3.3 mm). The tonsils emigrated cranially 6.5±4.8 mm. While preoperative mean syringo-cord ratio was 66.3%±13.3, post-operatively was 12.1%±12.7 (p<0.0001). A complete collapse of the syrinx was observed in 39% of the patients. Long-term improvements were obtained in 73% of the cases and 27% were unchanged. No patient got worse. We conclude that in the treatment of syringomyelia associated with Chiari I malformation an artificial cisterma magna of sufficient size must be created. This is achieved by means of an extensive sub-occipital craniotomy and C₁ laminectomy, followed by dural opening. Small bone removal with limited enlargement of theposterior fossa often results in failures of treatment and recurrences. Tonsillar removal is not necessary to obtain a good reconstruction of the cisterma magna.     

脊柱侧凸伴发Chiari畸形和脊髓空洞的影像学特征及临床意义

目的探讨脊髓空洞源性脊柱侧凸的影像学特征以及Chiafi畸形、脊髓空洞与脊柱侧凸影像学模式之间的相关性，并评估其临床意义。方法根据侧凸Cobb角的不同，将87例伴发Chiafi畸形和脊髓空洞的脊柱侧凸患者分为三组：A组（10°≤Cobb角≤30。）13例，B组（300°〈Cobb角≤600）42例，C组（Cobb角〉60°）32例。以特发性脊柱侧凸的影像学特征作为参考，将伴发Chiari畸形和脊髓空洞的脊柱侧凸模式分为典型和不典型两类，并测量胸椎后凸和腰椎前凸的Cobb角。在MRIT。加权像正中矢状面扫描层面上测量小脑扁桃体下移程度、空洞的形态和长度以及空洞与脊髓的最大比值（S／C最大比值），并对以上测量指标进行比较分析。结果87例患者中不典型侧凸的总发生率为43．7％（38／87例），其中左胸弯的发生率为42．5％。典型侧凸模式中不典型特征总发生率为65．3％。三组之间，不典型侧凸的发生率、典型侧凸中不典型特征的发生率差异均无统计学意义（P〉0．05）。三组间胸椎后凸差异有统计学意义（P〈0．05）。小脑扁桃体下移程度、脊髓空洞的长度和形态以及S/C最大比值与脊柱侧凸严重程度、不典型侧凸发生率之间均没有相关性（P〉0．05）。结论对于具有不典型侧凸模式、典型侧凸模式包含不典型特征、胸椎正常后凸或过度后凸的脊柱侧凸患者，术前全脊髓MR扫描应作为常规检查。小脑扁桃体下移程度和脊髓空洞模式对脊柱侧凸的进展和不典型侧凸的发生均未见明显影响。     

Chiari I malformation related syringomyelia: radionuclide cisternography as a predictor of outcome

Summary Background. This prospective study, conducted in patients with Chiari I malformation (C I) related syringomyelia who underwent posterior decompression and duroplasty, utilizes radionuclide cisternography in order to study the cerebrospinal fluid (CSF) dynamics at the foramen magnum and to predict the clinical outcome following surgery.Methods. 17 consecutive patients of C I with syringomyelia (but without hydrocephalus or fixed atlanto-axial dislocation), underwent a detailed neurological examination and were assigned a clinical disability score based on the modified Klekamp and Samii score. A radionuclide cisternography (using Tc99m-DTPA) was performed via the lumbar route and the ascent of the tracer was followed utilizing a gamma camera immediately after injection and then sequentially after 1, 2, 4, 6 and 24 hours. After posterior decompression and duroplasty, the modified Klekamp and Samii score was repeated at follow-up visits (range: 3 months to one year) along with radionuclide cisternography at 3 months, and MR imaging at 6 months.Findings. Three patterns of tracer flow were observed: a) rapid flow (n=7); b) supratentorial subarachnoid delay (n=7); and, c) foramen magnum block (n=3). The patients having foramen magnum block had the poorest clinical scores on admission. At follow up, there was an improvement in the clinical scores so that the mean scores in all three categories reached nearly the same level. Following posterior decompression, the radionuclide cisternography performed in 10 patients showed a rapid flow of the tracer without any obstruction. The syrinx resolved in 4 of the 11 patients in whom an MRI was done.Interpretation. The patients with C I with syringomyelia may often have a free flow of tracer across the FM. Posterior decompression and duroplasty provides maximum clinical relief in patients with a demonstrable foramen magnum block on radionuclide cisternography while those with a normal flow have less relief. The symptomatology related to brain-stem compression immediately responds to the surgical procedure but the syrinx-induced signs and symptoms of spinal cord dysfunction persist.     

Chiari I malformation accompanied by assimilation of the atlas, Klippel-Feil syndrome, and syringomyelia: case report

BACKGROUND: Chiari I malformation, accompanied by superposed bony anomaly of the craniovertebral junction, is comparatively rare. We report a case of Chiari I malformation accompanied by assimilation of the atlas, Klippel-Feil syndrome, and syringomyelia. CASE DESCRIPTION: The patient was a 61-year-old woman demonstrating numbness of the extremities, sensory impairment, muscular weakness, and tendon hyper-reflexia. X-ray images and CT scans demonstrated assimilation of the atlas to the occipital bone, C2 and C3 fusion, abnormal passage of the vertebral arteries, and an anomalous bony mass on the right lateral mass of the atlas protruding into the spinal column. The odontoid process was also deviated to the left. Magnetic resonance images demonstrated bilateral descent of the cerebellar tonsils and syringomyelia extending from C6 to T8. Computed tomographic scans with the head rotated to the right demonstrated increased narrowing of the vertebral column caused by the right lateral mass of the atlas, and MR images confirmed exaggerated deformation of the spinal cord at the same region. This deformation manifested no neurologic symptoms, and we therefore performed foramen magnum decompression and duraplasty using Gore-Tex (W.L. Gore & Associates, Inc., Flagstaff, AZ). In the early postoperative period, neurologic symptoms improved. CONCLUSION: We believe it is important that a treatment plan for Chiari I malformation accompanied by bony anomaly of the craniovertebral junction be determined based on morphologic investigation of the region supplemented by dynamic imaging-based evaluation of instability, or a careful inspection for atypical passage of the vertebral arteries, a frequent site of complication.     

Long-term outcome of surgical management of adult Chiari I malformation

Chiari I malformation continues to inspire controversy. Debate still exists about surgical options. The aim of this study is to evaluate the long-term outcome of posterior fossa decompression procedure (PFD) in the treatment of adult Chiari I malformation, focusing on some factors or technical aspects which might influence the outcome. Forty-six adult patients with Chiari I malformation operated by PFD are the subject of this study. The group included 21 males and 25 females, with mean age of 37.4?years. Patients were divided into two groups: group I (32 cases) with syringomyelia and group II (14 cases) without syringomyelia. Group I was further subdivided into three subgroups according to the surgical procedure adopted: group Ia (12 cases) operated by PFD only, group Ib (14 cases) operated by PFD with fourth ventricular shunt, and group Ic (six cases) operated by PFD and syringosubarachnoid shunt. All cases included in group II were operated by PFD only. In group I, symptoms improved in 14 cases (43.8?%) and stabilized in 18 cases (56.3?%), whereas in group II, symptoms resolved in ten cases (71.4?%) and improved in four cases (28.6?%). Postoperative magnetic resonance imaging showed that the syrinx was resolved in 21 cases (65.6?%), improved in seven cases (21.9?%), and unchanged in four cases (12.5?%). Among the mean follow-up period (5.8?years), recurrence of symptoms occurred in five cases (10.9?%), all of them are included in group I, and were reoperated again. Posterior fossa decompression is recommended as the treatment of choice in adult Chiari I malformation with or without syringomyelia. The presence of syringomyelia predicts a less favorable response to surgical intervention. Syringosubarachnoid shunting did not improve the long-term outcome either clinically or radiologically. Implanting a fourth ventricular shunt in cases of syringomyelia associated with adhesions at the foramen of Magendie decreases the long-term incidence of recurrence significantly. For recurrent cases, re-exploration of the initial posterior fossa decompression is recommended before any consideration is given for direct management of the syrinx.     

Chiari I malformation with syringomyelia. Evaluation of surgical therapy by magnetic resonance imaging

Five patients with a Chiari I-syringomyelia complex of adult onset were evaluated by magnetic resonance (MR) imaging. All patients underwent suboccipital craniotomy with upper cervical (C-1 and part of C-2) laminectomy, arachnoid retraction, and duraplasty. Postoperative MR studies of four patients disclosed collapse of the syringomyelic cavity, even when the cavity extended into the thoracic region. This appeared to be a progressive process taking place over several weeks. Operative complications are noted and physiological implications are discussed.     

Chiari I malformation in parturients

STUDY OBJECTIVE: To assess complications of regional as well as general anesthesia in parturients with Chiari I malformation. DESIGN: Retrospective chart review. SETTING: Academic medical center. PATIENTS: All parturients in our institution who had the diagnosis of Chiari I malformation and delivered in our hospitals over a 50-year period. MAIN RESULTS: 12 parturients delivered 30 babies. Three deliveries were facilitated with general anesthesia. Nine deliveries were facilitated with central axis anesthesia, six with epidural anesthesia, two with a single injection of a spinal anesthetic, and one with a continuous spinal catheter. The patient who received a continuous spinal catheter developed a postdural puncture headache that resolved with an epidural blood patch. None of the patients who received general, spinal, or epidural anesthesia for their deliveries developed symptoms or had exacerbation of preexisting symptoms of Chiari I malformation. CONCLUSIONS: General anesthesia, as well as spinal and epidural anesthesia, appeared to be safe and effective in our series of vaginal or cesarean delivery patients. The small number of patients in our series does not negate the cautious recommendations of others, but suggests that general anesthesia, as well as spinal or epidural anesthesia, can be used safely and effectively in these patients.     

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.