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.     

Superimposed chronic subdural hygromas. Report of two cases.

Two cases are reported of separate but superimposed chronic subdural collections occurring over one cerebral hemisphere convexity. It is suggested that this phenomenon may account for some apparent recurrences of chronic subdural collections after simple burr-hole evacuation.     

Management of infratentorial subdural hygroma complicating foramen magnum decompression: a report of three cases

Decompression of the foramen magnum for symptomatic Chiari malformation attends a small but significant risk of infratentorial subdural extra-arachnoid hygroma when an arachnoid-sparing procedure is attempted. We present three cases whereby an arachnoid-sparing procedure was carried out and resulted in infratentorial subdural hygroma and hydrocephalus. The complication was managed by re-exploration of the posterior fossa and wide arachnoidotomy. In cases whereby the decision has been made to open the dura, we recommend routine arachnoidotomy in foramen magnum decompression, avoiding the risks of infratentorial subdural hygroma. In cases where arachnoid-sparing procedures have been attempted and subdural hygroma subsequently develops, we advocate re-exploration of the posterior fossa rather than cerebrospinal fluid diversion.     

Curve progression in scoliosis associated with Chiari I malformation following suboccipital decompression

Nine children with scoliosis and Chiari I malformations were followed 1-11 years after suboccipital decompression. Eight also had syringomyelia. Despite initial curve stabilization, at final follow-up eight curves were of the magnitude to require spinal fusion. Neither bracing nor secondary neurosurgical procedures arrested progressive curves.     

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.     

Paroxysmal rage as a presenting symptom of the Chiari I malformation. Report of two cases.

Signs of meningeal irritation including occipital and cervical pain are common in symptomatic children with the Chiari I malformation. The author reports on two children with Chiari I malformations who presented with a previously undescribed symptom presumably caused by intermittent meningeal irritation: paroxysmal rages. In both cases the rages stopped after decompressive surgery. Evaluation including magnetic resonance imaging should be considered in children with new onset of paroxysmal behavioral disorders.     

Chiari I malformation with traumatic syringomyelia and spontaneous resolution: case report and literature review.

A case history of a 28-year-old woman who sustained a moderately severe head injury and then developed acute bilateral arm weakness is presented. Magnetic resonance imaging studies revealed a Chiari I malformation with a large cervical syringomyelia (hydromyelia). The patient's arm weakness almost completely resolved spontaneously as did her syrinx. How this case is interpreted in light of the various theories of pathogenesis will be discussed.     

Intradiploic pseudomeningocele and ossified occipitocervical pseudomeningocele after decompressive surgery for Chiari I malformation: report of two cases and literature review

Intradiploic cerebrospinal fluid (CSF) collections are rare findings. The authors describe two pediatric patients with iatrogenically induced occipital CSF collections after decompressive surgery for Chiari I malformation. The first patient presents a large occipital intradiploic pseudomeningocele and the second patient an intradiploic pseudomeningocele merging with an ossified occipitocervical pseudomeningocele. Though being rarities after decompression for Chiari I malformation, intradiploic fluid collection and ossified pseudomeningocele should be considered if patients represent with aggravating presurgical or new symptoms.     

Resolution of trigeminal neuralgia following third ventriculostomy for hydrocephalus associated with Chiari I malformation: case report.

OBJECTIVE AND IMPORTANCE: Cranial nerve dysfunction, including trigeminal neuralgia, has been associated with Chiari I malformations. In such cases, trigeminal neuralgia is thought to be related to tonsillar compression of the brainstem or to traction on the cranial nerves. Hydrocephalus may be a contributing factor. CLINICAL PRESENTATION: A 38-year-old woman had right-sided lancinating facial pain typical of trigeminal neuralgia but was otherwise neurologically intact. Magnetic resonance imaging showed no evidence of a compressing vessel. Moderate hydrocephalus and a Chiari I malformation were noted incidentally. The visibility of the aqueduct was poor. INTERVENTION: The patient underwent a third ventriculostomy and her symptoms resolved completely. CONCLUSION: This is the first case in which trigeminal neuralgia was treated with a third ventriculostomy and one of only four cases of isolated trigeminal neuralgia associated with a Chiari malformation. Acquired aqueductal stenosis may have caused the hydrocephalus which, in turn, caused the Chiari malformation configuration that caused the trigeminal neuralgia. The rationale for the treatment modality and possible causes of Chiari I-induced trigeminal neuralgia are discussed.     

Extra-arachnoidal cranio-cervical decompression for syringomyelia associated with Chiari I malformation in adults: technique assessment

Summary Background. The osteo-dural decompression of the cerebellar tonsils at the cranio-cervical junction is generally considered the most effective treatment for syringomyelia-Chiari I complex. However much controversy concerning a great number of surgical adjuvants to the standard bony decompression is still present. In this work an extra-arachnoidal cranio-cervical decompression (CCD) without duroplasty is described and the surgical results are reported. Method. Between 2000 and 2005, 24 adult patients underwent surgery for symptomatic syringomyelia-Chiari I complex not associated with hydrocephalus. In all cases, the surgical procedure consisted of a limited suboccipital craniectomy and laminectomy of C1 (when necessary C2 as well) followed by dural opening leaving the arachnoid membrane intact. The dura mater is left open and stitched laterally to the muscles. Findings. With a mean clinical long term follow-up of 44 months (range, 12–78 mo), neurological disturbances improved in 21 of 24 patients (87.5%) as result of extra-arachnoidal CCD. The postoperative complications occurred when the arachnoid was accidentally violated (4 cases, 16.6%). The complications included aseptic meningitis (one patient), nucal pseudomeningocele (two patients) and postoperative hydrocephalus requiring a ventriculoperitoneal shunt (one patient). Finally, one patient received an additional C2 laminectomy in order to obtain symptoms improvement and syrinx shrinkage. Postoperative MRI studies demonstrated that the syrinx decreased in size or collapsed in 20 patients (83.3%) and stabilized in 4 (16.7%). Conclusions. The extra-arachnoidal CCD is a safe and effective treatment for syringomyelia associated with Chiari I malformation in adults without intraoperative evidence of adhesive arachnoiditis. However a larger number of patients and longer follow-up will be necessary to determine the efficacy of extra-arachnoidal CCD.     

Acute bilateral epidural hematomas. Report of two cases and review of the literature

Two cases of acute postraumatic bilateral epidural hematomas with different clinical pictures are presented. In the review of the literature, acute, subacute and delayed bilateral epidural hematomas must be found. Clinical findings, results of CT scan and pathophysiology are discussed.     

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.     

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.     

Clinical outcomes in patients with Chiari I malformation: a review of 27 cases

BACKGROUND: Chiari I malformation is a congenital maldevelopment defined as downward herniation of the cerebellar tonsils through the foramen magnum. It has been treated using a variety of surgical procedures. Surgical outcomes have been reported with varying results throughout the literature. METHODS:We retrospectively reviewed 27 patients with Chiari I malformation operated at the University Hospital during a 9-year period from 1988 to 1997. We assessed preoperative and postoperative signs and symptoms in all the patients including headache, neck pain, nystagmus, vertigo, weakness, spasticity, atrophy, numbness, pain and temperature dissociation, diplopia, dysphagia, and sphincter dysfunction. Each patient was analyzed to determine if there was an arrest in the progression of the disease after surgical intervention. RESULTS: Syringomyelia was present in 59% of the patients. Only 1 patient who presented with neck pain improved. One patient reported new onset headache, and one patient described his headache resolved. Vertigo resolved in three patients; two patients stated mild improvement, and one patient reported worsening. Nystagmus improved or resolved in six patients. Weakness improved in only two patients who did not have syringomyelia. Dysphagia improved in two patients, and in the others it remained unchanged. Diplopia, spasticity, atrophy, and numbness remained unchanged. CONCLUSIONS: Our study provides evidence that the main benefit of the surgical management in patients with Chiari I malformation with or without syringomyelia is to arrest the progression of the disease.     

Subacute subdural hygroma and presyrinx formation after foramen magnum decompression with duraplasty for Chiari type 1 malformation

A 15-year-old girl developed a rare case of subdural hygroma after foramen magnum decompression for Chiari type 1 malformation manifesting as rapid symptom deterioration around 10 days after uncomplicated operation with uneventful immediate postoperative course. Progressive enlargement of the subdural hygroma in both supra- and infratentorial spaces was followed by the development of hydrocephalus. Syringomyelia improved shortly after the first operation but then deteriorated with massive presyrinx formation. Reoperation with wide opening of the arachnoid membrane lead to a rapid resolution of the hydrocephalus and the presyrinx. The present case shows that wide opening of the arachnoid membrane is an effective therapeutic option.     

Xanthogranulomatous pyelonephritis associated with renal cell carcinoma. Report on two cases and review of the literature

Xanthogranulomatous pyelonephritis is a rare and particularly aggressive variant of chronic destructive pyelonephritis. Even when all modern diagnostic possibilities are exhausted, it is often not possible to distinguish xanthogranulomatous pyelonephritis from a renal cell carcinoma preoperatively. In clinical practice false diagnoses are therefore frequent. The coexistence of xanthogranulomatous pyelonephritis and renal cell carcinoma is extremely rare. We report 2 such cases. In 1 case surgery was performed on the kidney affected by xanthogranulomatous pyelonephritis using a renal sparing technique.