Johann Conrad Brunner (1653-1727) and the first description of syringomyelia.

INTRODUCTION: Johann Conrad Brunner (1653-1727) was a European anatomist and physician whose research concerning the pancreas and duodenum has made him a prominent figure in medicine. However, Brunner should also be recognized for his descriptions of syringomyelia, which were originally published in 1688 and included in the second edition of Theophilus Boneti's compendium of postmortem examinations, the Sepulchretum, which was published in 1700. CONCLUSIONS: Our current understanding of syringomyelia is based on the early observations of researchers such as Johann Conrad Brunner.

C4 to C7 Laminoplasty for Resection of an Intradural Intramedullary Ependymoma: 2-Dimensional Operative Video.

A 28-year-old woman with a history of a prolactinoma presented with about 5 months of neck pain and left upper extremity numbness and tingling in the C7 and C8 dermatomal distribution. She had no weakness on examination though notable increased deep tendon reflexes in the lower extremities. She had a homogenously enhancing lesion with an associated syrinx on MRI of her cervical spine. She was offered a C4-7 laminoplasty for resection of the tumor and ultimate tissue diagnosis. The patient consented to the procedure. Her postoperative imaging was notable for gross total resection and significant improvement of the syrinx and cervical alignment. Clinically, her paresthesias and gait improved significantly. The pathology confirmed a diagnosis of World Health Organization grade II ependymoma. The management of ependymomas in adults often starts with surgical resection for cytoreduction followed by postoperative radiotherapy for World Health Organization grade II and grade III at least.1-4 Spinal cord ependymomas tend to have favorable prognosis, except when carrying an MYCN gene amplification.5,6.

Chiari Type I Revision Decompressive Surgery Indications and Operative Technique: Experience in a Large Adult Cohort.

BACKGROUND: Chiari malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, frequently resulting in strain related headaches, and motor/sensory dysfunction. Chiari decompression technique varies significantly, possibly contributing to frequent revisions. We reviewed revision Chiari decompressions at our institution to determine the primary indications for revision and outcomes after revision. METHODS: We retrospectively reviewed patients who underwent revision of Chiari decompression at our institution from 2005 to 2020. Demographics, indications for revision surgery, operative techniques, imaging findings, and preoperative/postoperative symptoms were collected. χ2 test was performed to determine statistical significance using a P < 0.05. Independent predictors of operative outcomes were identified. RESULTS: A total of 46 patients (91% females, mean age 38.8 years) were included for analysis. The median time to revision surgery was 69.1 months (range 0-364 months) with headache (n = 37, 80%) being the most commonly recurring symptom. Large craniectomy (n = 28, 61%) was the most frequent indication for revision surgery. Thirty-two (70%) patients underwent cranioplasty, 20 (43%) required duraplasty, 15 (33%) required arachnoid dissection, and 15 (33%) required tonsillar reduction during revision surgery. Postrevision follow-up (at 8.9 ± 5.2 months average, range 1-18 months), revealed an average reduction in all Chiari-related symptoms relative to symptoms before the revision. CONCLUSIONS: The most common indication for revision Chiari decompression was a large craniectomy resulting in cerebellar ptosis. We found that tonsillar reduction paired with modest craniectomy achieved near-complete resolution of symptoms with minimal complications. For patients with recurrent or persistent sequelae of Chiari malformation after decompression, revision may reduce symptom severity.

Short-Term and Long-Term Complications Associated with Posterior Fossa Decompression for Chiari Malformation.

Surgery is the treatment of choice for symptomatic patients with Chiari anomalies Although the surgical treatment of Chiari anomalies in adults is a straightforward procedure, complications and less than satisfactory outcomes do occur. Understanding these complications is important for correcting the problem as well as preventing the recurrence of similar problems. In this article, the author review the short-term and long-term complications associated with posterior fossa decompression for Chiari malformation.

Tandem resection of multiple spinal schwannomas.

This video depicts the resection of three separate intradural extramedullary spinal tumors performed under the same anesthetic. Neuromonitoring was used to identify motor nerve roots, and laminoplasty was performed at the thoracolumbar junction to preserve alignment and minimize the risk of postoperative CSF leak.

A Novel Untethering and Duraplasty Technique for Postsurgical Tethered Spinal Cord.

Progressive post-traumatic postsurgical myelopathy (PPPM) is a known entity that can occur months to years after the initial insult. Symptomatic patients can become myelopathic and have rapid and progressive neurological decline. Surgical correction of PPPM usually involves intradural exploration and lysis of adhesions that carries the risk of further injury to the spinal cord. In this manuscript, we provide a report of a patient presenting more than 50 years after the initial resection of an intramedullary tumor. Additionally, we present and describe a novel surgical technique for managing this difficult problem and restoring normal CSF dynamics.

Idiopathic thoracic spinal cord herniation: report of 10 patients and description of surgical approach.

STUDY DESIGN: Ten patients with idiopathic spinal cord herniation were treated surgically to reduce the herniation. In 9 patients, a sling was passed between the spinal cord and the anterior dural hiatus. The results were analyzed with respect to the neurological symptoms and imaging. OBJECTIVE: The study calls attention to an unusual condition with similar clinical presentation and characteristic imaging findings in the hope of improving early recognition and treatment. We present the outcome of treating patients with a safe technique that avoids the risks of primary dural closure and of cerebrospinal fluid leakage. SUMMARY OF BACKGROUND DATA: Over 100 patients with this disorder have been reported in the literature. Treatment in the past has included potentially hazardous attempts at primary dural closure of the dural hiatus, and the contraindicated step of biopsy, or even resection of herniated tissue. Various different surgical approaches have been used and the technique described by us has proved to be safe and effective. METHOD: : Nine patients underwent treatment by a similar sling technique; 1 patient was treated by a 2-stage more complex approach, which we have since abandoned. We begin with a laminectomy over the suspected level of cord herniation, followed by dural opening. The dentate ligaments are sectioned and the dural defect may have to be enlarged to safely disengage the herniated cord. The cord is elevated by the dentate ligaments and a bovine pericardial sling is passed under the cord, thereby occluding the dural hiatus. The epidural cavity and site of herniation may be filled with a variety of material, and an expansile duraplasty is performed. RESULTS: Sensory symptoms, weakness and spasticity, among the most common findings, improved in approximately one third of our patients. A long time interval between the appearance of symptoms, correct diagnosis, and appropriate treatment may reduce the chance of significant recovery. Severe pain may be a poor prognostic sign. The dural hiatus was located in the upper thoracic region in all of our patients. CONCLUSIONS: Idiopathic spinal cord herniation presents with symptoms and signs of spinal cord dysfunction and a very characteristic imaging appearance. The condition can be treated safely, with the expectation of neurological stabilization and some improvement. The technique described minimizes cord manipulation. Postoperative imaging often reflects the long-standing incarceration of the spinal cord.

Structural Changes in the Cervicomedullary Junction in Adult Chiari Patients.

OBJECTIVE: To assess volumetric changes in the spinal cord at the cervicomedullary junction, diameter of the cervicomedullary cord, and width of the brainstem following posterior fossa decompression (PFD). METHODS: A retrospective analysis of adult patients with Chiari malformation who underwent PFD was performed. Segmentations were done on clinical quality T2-weighted cervical magnetic resonance images obtained before and after decompression using ITK-SNAP. Volumes of neural tissue within the cervicomedullary junction were evaluated from 10 mm cranial to the medullary beak to the cervical spinal cord at the level of the caudal endplate of the second cervical vertebra. The diameter of the cervicomedullary cord was calculated perpendicular to the spinal cord. The width of the brainstem was measured perpendicular to the clivus at the level of the basion. RESULTS: Twenty adult patients, a mean age of 49.55 years, were included. The cervical cord increased in volume by 13 mm3 to 338 mm3, with an average increase of 155 mm3 (P-value of 0.00002). The diameter of the cervicomedullary cord increased 10.30% 7 mm superior to the beak (P-value of 0.00074), 11.49% at the apex of the beak (P-value of 0.00082), 8.29% 7 mm inferior to the beak (P-value of 0.00075), and the brainstem increased 14.46% perpendicular to the clivus (P-value of 0.00109). The spinal cord at the inferior aspect of the C3 vertebra changed insignificantly (P-value of 0.10580). CONCLUSION: The volume of the cervical cord at the cervical-medullary junction, width of the cervicomedullary cord, and diameter of the brainstem increase following PFD.

Chiari malformation and syringomyelia.

Chiari malformation was first described over a century ago, and consists of posterior fossa anomalies that generally share the feature of cerebellar tonsillar descent through the foramen magnum. Our understanding of this disorder was initially based on autopsy studies, and has been greatly enhanced by the advent of MRI. The surgical management of Chiari anomalies has also evolved in a parallel fashion. Although the exact surgical technique varies among individual surgeons, the goals of surgery remain constant and consist of relieving brainstem compression and cranial nerve distortion, restoring the normal flow of CSF across the foramen magnum, and reducing the size of any associated syrinx cavity. Syrinx cavities are most commonly associated with Chiari anomalies, yet primary spinal syringomyelia (PSS) can be caused by traumatic, infectious, degenerative, and other etiologies that cause at least a partial CSF flow obstruction in the spinal subarachnoid space. As with syringomyelia associated with Chiari anomalies, the main goal of PSS surgery is to reestablish CSF flow across the area of obstruction. In addition to MRI, myelography with CT can be very helpful in the evaluation and management of these patients by identifying focal regions of CSF obstruction that may be amenable to surgical intervention. Future directions for the treatment of Chiari anomalies and syringomyelia include the application of advanced imaging techniques, more widespread use of genetic evaluation, large-scale outcome studies, and the further refinement of surgical technique.

Clinical and surgical management of holocervical spinal cord ependymomas.

BACKGROUND: Spinal ependymomas are rare tumors of the central nervous system, and those spanning the entire cervical spine are atypical. Here, we present two unusual cases of holocervical (C1-C7) spinal ependymomas. CASE DESCRIPTION: Two patients, a 32-year-old female and a 24-year-old male presented with neck pain, motor, and sensory deficits. Sagittal MRI confirmed hypointense lesions on T1 and hyperintense regions on T2 spanning the entire cervical spine. These were accompanied by cystic cavities extending caudally into the thoracic spine and rostrally to the cervicomedullary junction. Both patients underwent gross total resection of these lesions and sustained excellent recoveries. CONCLUSION: Two holocervical cord intramedullary ependymomas were safely and effectively surgically resected without incurring significant perioperative morbidity.

Development of Common Data Elements for Use in Chiari Malformation Type I Clinical Research: An NIH/NINDS Project.

The management of Chiari I malformation (CMI) is controversial because treatment methods vary and treatment decisions rest on incomplete understanding of its complex symptom patterns, etiologies, and natural history. Validity of studies that attempt to compare treatment of CMI has been limited because of variable terminology and methods used to describe study subjects. The goal of this project was to standardize terminology and methods by developing a comprehensive set of Common Data Elements (CDEs), data definitions, case report forms (CRFs), and outcome measure recommendations for use in CMI clinical research, as part of the CDE project at the National Institute of Neurological Disorders and Stroke (NINDS) of the US National Institutes of Health. A working group, comprising over 30 experts, developed and identified CDEs, template CRFs, data dictionaries, and guidelines to aid investigators starting and conducting CMI clinical research studies. The recommendations were compiled, internally reviewed, and posted online for external public comment. In October 2016, version 1.0 of the CMI CDE recommendations became available on the NINDS CDE website. The recommendations span these domains: Core Demographics/Epidemiology; Presentation/Symptoms; Co-Morbidities/Genetics; Imaging; Treatment; and Outcome. Widespread use of CDEs could facilitate CMI clinical research trial design, data sharing, retrospective analyses, and consistent data sharing between CMI investigators around the world. Updating of CDEs will be necessary to keep them relevant and applicable to evolving research goals for understanding CMI and its treatment.

Esophageal injury associated with anterior cervical spine surgery.

BACKGROUND: Anterior cervical spinal surgery has been used to treat a variety of conditions including spondylosis, fracture, tumor, infection, trauma, and instability. Esophageal perforation, a rare and unusual complication of anterior cervical procedures, has been largely relegated to only incidental case reports with few large retrospective studies performed to determine true incidence, treatment, etiology, and outcome. METHODS: More than 3000 anterior cervical spine surgeries conducted over a 30-year period by 5 active practicing surgeons were reviewed. There were 3 cases of esophageal injury identified with subsequent critical evaluation to determine presentation, diagnosis, risk factors, management, and outcomes. In addition, incidence rates were calculated based on overall occurrence and antecedent risk factors. RESULTS: Two of the patients with esophageal injury had predisposing risk factors, including diverticula or cervical spine trauma. The third patient had no antecedent risk factors. Symptoms included axial spine pain, odynophagia, dysphagia, purulent spondylitis, and sepsis. Treatment consisted of one or more of the following: reoperation with exploration and repair, esophageal diversion, esophageal rest, antibiotic administration, and wound drainage. Functional outcomes were achieved in all cases with no deaths. CONCLUSIONS: Esophageal injury incidence based on overall occurrence in this study was 0.1%. Patients with no antecedent risk factors had an incidence of 0.03%. Our results compare favorably with those of the Cervical Spine Research Society survey from 1989, which predicted an incidence of 0.25% based on questionnaires filed by surgeons, representing 1 of only 2 reports that included more than 1000 patients.

Thecal shunt placement for treatment of obstructive primary syringomyelia.

OBJECT: The most commonly reported treatment of primary syringomyelia has been laminectomy with duraplasty or direct shunting from the syrinx cavity. Diversion of cerebrospinal fluid (CSF) from the spinal subarachnoid space to peritoneal, atrial, or pleural cavities has been described previously in only a few case reports. Shunting of the CSF from the subarachnoid space rostral to the level of myelographic blockage may reduce the filling force of the syrinx cavity and avoids myelotomy and manipulation of the spinal cord parenchyma. The authors report on 7 patients who underwent thecal shunt placement for primary spinal syringomyelia. METHODS: This study is a retrospective review of a consecutive series. The authors reviewed the medical records and neuroimaging studies of 7 adult patients with posttraumatic, postsurgical, or postinflammatory syringomyelia treated with thecoperitoneal, thecopleural, or thecoatrial shunt placement at the University of California Los Angeles Medical Center. Myelographic evidence of partial or complete CSF flow obstruction was confirmed in the majority of patients. The mean duration of follow-up was 33 months (range 6-104 months). RESULTS: Six (86%) of 7 patients showed signs of clinical improvement, whereas 1 remained with stable clinical symptoms. Of the 6 patients with available postoperative imaging, each demonstrated a reduction in syrinx size. Three patients (43%) had > or = 1 complication, including shunt-induced cerebellar tonsillar descent in 1 patient and infections in 2. CONCLUSIONS: If laminectomy with duraplasty is not possible for the treatment of primary syringomyelia, placement of a thecoperitoneal shunt (or thecal shunt to another extrathecal cavity) should be considered. Although complications occurred in 3 of 7 patients, the complication rate was outweighed by a relatively high symptomatic and imaging improvement rate.

Syringomyelia associated with intradural arachnoid cysts.

OBJECT: Intradural arachnoid cysts are relatively uncommon pouches of cerebrospinal fluid (CSF) found within the subarachnoid space. The authors present a series of eight symptomatic patients in whom syrinx cavities were associated with arachnoid cysts, and they discuss treatment strategies for this entity. METHODS: The population comprised eight men whose mean age was 50 years (range 35-81 years). All patients experienced gait difficulty, and it was the chief complaint in seven; arm pain was the primary complaint in one. No patient had a history of spinal trauma, meningitis, or previous spinal surgery at the level of the syrinx cavity or arachnoid cyst. In each patient imaging revealed a syrinx cavity affecting two to 10 vertebral levels. Posterior thoracic arachnoid cysts were found in proximity to the syrinx cavity in each case. There was no evidence of cavity enhancement, Chiari malformation, tethered cord, or hydrocephalus. All patients underwent thoracic laminectomy and resection of the arachnoid cyst wall, and postoperative neurological improvement was documented in each case. The mean follow-up duration was 19 months (range 4-37 months). Follow-up magnetic resonance imaging demonstrated the disappearance of the arachnoid cyst and a significant decrease in syrinx cavity size in each patient. CONCLUSIONS: Spinal arachnoid cysts can be associated with syringomyelia, likely due to alterations in normal CSF dynamics. In symptomatic patients these cysts should be resected and the normal CSF flow restored. The results of the present series indicate that neurological improvement and reduction in syrinx cavity size can be achieved in patients with syringomyelia associated with intradural arachnoid cysts.

Primary spinal syringomyelia. Invited submission from the joint section meeting on disorders of the spine and peripheral nerves, March 2005.

In the present review the author describes the different types of syringomyelia that originate from abnormalities at the level of the spinal cord rather than at the craniovertebral junction. These include posttraumatic and postinflammatory syringomyelia, as well as syringomyelia associated with arachnoid cysts and spinal cord tumors. The diagnosis and the principles of managing these lesions are discussed, notably resection of the entity restricting cerebrospinal fluid flow. Placement of a shunt into the syrinx cavity is reserved for patients in whom other procedures have failed or who are not candidates for other procedures.

Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment.

OBJECT: Because lumbar magnetic resonance (MR) imaging fails to identify a treatable cause of chronic sciatica in nearly 1 million patients annually, the authors conducted MR neurography and interventional MR imaging in 239 consecutive patients with sciatica in whom standard diagnosis and treatment failed to effect improvement. METHODS: After performing MR neurography and interventional MR imaging, the final rediagnoses included the following: piriformis syndrome (67.8%), distal foraminal nerve root entrapment (6%), ischial tunnel syndrome (4.7%), discogenic pain with referred leg pain (3.4%), pudendal nerve entrapment with referred pain (3%), distal sciatic entrapment (2.1%), sciatic tumor (1.7%), lumbosacral plexus entrapment (1.3%), unappreciated lateral disc herniation (1.3%), nerve root injury due to spinal surgery (1.3%), inadequate spinal nerve root decompression (0.8%), lumbar stenosis (0.8%), sacroiliac joint inflammation (0.8%), lumbosacral plexus tumor (0.4%), sacral fracture (0.4%), and no diagnosis (4.2%). Open MR-guided Marcaine injection into the piriformis muscle produced the following results: no response (15.7%), relief of greater than 8 months (14.9%), relief lasting 2 to 4 months with continuing relief after second injection (7.5%), relief for 2 to 4 months with subsequent recurrence (36.6%), and relief for 1 to 14 days with full recurrence (25.4%). Piriformis surgery (62 operations; 3-cm incision, transgluteal approach, 55% outpatient; 40% with local or epidural anesthesia) resulted in excellent outcome in 58.5%, good outcome in 22.6%, limited benefit in 13.2%, no benefit in 3.8%, and worsened symptoms in 1.9%. CONCLUSIONS: This Class A quality evaluation of MR neurography's diagnostic efficacy revealed that piriformis muscle asymmetry and sciatic nerve hyperintensity at the sciatic notch exhibited a 93% specificity and 64% sensitivity in distinguishing patients with piriformis syndrome from those without who had similar symptoms (p < 0.01). Evaluation of the nerve beyond the proximal foramen provided eight additional diagnostic categories affecting 96% of these patients. More than 80% of the population good or excellent functional outcome was achieved.

Clinical Presentation and Alternative Diagnoses in the Adult Population.

This article describes the presentation of tussive headaches in the adult population. Posterior headaches can also occur in patients with basilar invagination, and they may require occipital cervical fusion. Lower cranial nerve dysfunction is another common presenting symptom in adult Chiari patients. Almost 25% of symptomatic adult Chiari patients had a recent episode of trauma. Syringomyelia is not present in all Chiari patients possibly because of the involution of the central canal. Adults must also be evaluated for other causes of acquired Chiari malformations such as pseudotumor cerebri.

Slitlike syrinx cavities: a persistent central canal.

OBJECT: The authors review their experience in the diagnosis and management of 32 patients with slitlike syrinx cavities. METHODS: There were 18 men and 14 women with a mean age of 40 years. Presenting symptoms that prompted magnetic resonance (MR) imaging evaluation were mechanical spinal pain (13 patients), radicular pain (seven patients), paresthesia (six patients), numbness (five patients), and muscle spasm (one patient). In 12 patients neurological examination demonstrated normal status, and in the remainder only minimal sensory or motor abnormalities were found. The mean diameter of the syrinx cavity was 2 mm (range 1-5 mm), and on average it covered three vertebral levels. The cavities were limited to the cervical region in 16 patients, the thoracic in 12, and both regions in four patients. The mean follow-up time for changes in clinical condition and repeated MR imaging features were 38 and 32 months, respectively. Thirty-one patients were treated nonoperatively, and one was treated surgically. During the follow-up period clinical improvement was documented in six patients, worsened status in seven, and no change was demonstrated in the clinical status of 19 patients. None of the syrinx cavities changed in size. In 16 patients medical workup revealed alternative diagnoses that were determined to be the true causes of each patient's symptoms. CONCLUSIONS: Slitlike cavities likely do not represent true syringomyelia but rather remnants of the central canal detected in a small percentage of adults. Review of the authors' experience indicates that these cavities are asymptomatic and are unlikely to change in size. They can be considered an incidental finding, and in many of these patients another condition explaining the patient's symptoms may be found.

Syringomyelia associated with foramen magnum arachnoiditis.

OBJECT: Syringomyelia is often linked to pathological lesions of the foramen magnum. The most common cause is hindbrain herniation, usually referred to as Chiari I or II malformation. Foramen magnum arachnoiditis without either Chiari I or II malformation is a rare cause of syringomyelia. The authors undertook a retrospective analysis of 21 patients with foramen magnum arachnoiditis (FMA) and syringomyelia treated between 1978 and 2000 to determine clinical course and optimum management. METHODS: In the review of records, 21 patients with FMA and syringomyelia were documented. A stable clinical course was demonstrated in three patients in whom surgery was not performed, and one patient refused surgical intervention. Seventeen patients underwent 23 operations to treat progressive neurological disease. Of these 23 operations, 18 involved opening of the foramen magnum, arachnoid dissection, and placement of a large dural graft. One patient underwent insertion of a ventriculoperitoneal shunt for treatment of accompanying hydrocephalus, one patient received a cystoperitoneal shunt for an accompanying arachnoid cyst; two syringoperitoneal and one syringosubarachnoid shunts were also inserted. Hospital and outpatient files, neuroimaging studies, and intraoperative photographic and video material were analyzed. Additional follow-up information was obtained by telephone interview and questionnaires. Standard and cardiac-gated magnetic resonance imaging studies are the diagnostic procedures of choice in these patients. Sensory disturbances, dysesthesias, and pain were the only symptoms likely to improve after foramen magnum surgery. Motor weakness and gait disturbances, which were severe in a considerable number of patients, and swallowing disorders tended to remain unchanged. As a consequence of the rather severe arachnoid lesions in most patients, clinical recurrences were observed in 57% over a 5-year period. CONCLUSIONS: Surgery for FMA and syringomyelia has to provide clear cerebrospinal fluid pathways between the cerebellopontine cisterns, spinal canal, and fourth ventricle. If this can be achieved successfully, the syrinx decreases in size and the clinical course of the patient may even improve. In patients with severe and widespread areas of arachnoiditis, however, multiple operations may be required at least to stabilize the clinical course.

Posterior fossa reconstruction using titanium plate for the treatment of cerebellar ptosis after decompression for Chiari malformation.

OBJECTIVE: We describe our use of a perforated titanium plate to perform a partial posterior fossa cranioplasty in the treatment of cerebellar ptosis and dural ectasia after posterior fossa decompression (PFD). METHODS: Twelve patients who had undergone PFD underwent posterior fossa reconstruction using a titanium plate. Symptoms were related to either descent of the cerebellum into the decompression or to dural ectasia into the craniectomy defect. RESULTS: Twelve patients who had undergone large suboccipital craniectomies and who presented with persistent headaches and some with neurological symptoms related to syringomyelia, underwent reoperation with placement of a small titanium plate. Ten of 12 patients showed symptomatic improvement after reoperation. CONCLUSIONS: Placement of a titanium plate appears to be an effective method of treatment of cerebellar ptosis and dural ectasia after PFD for Chiari malformation.