Syringobulbia: a surgical appraisal

Successful treatment of unilateral facial nerve palsy in a pediatric patient with syringobulbia and Chiari malformation type I: illustrative case

BACKGROUND

Unlike syringomyelia, syringobulbia is not commonly observed in pediatric patients with Chiari malformation type I (CMI). Previous series have reported the incidence of syringobulbia as between 3% and 4% in these patients. Presentation is typically chronic, with the slow onset of neurological symptoms and cranial nerve (CN) palsies resulting from lower brainstem involvement. The authors report the first case of a pediatric patient with simultaneous CMI, syringobulbia, and unilateral CN VII palsy.

OBSERVATIONS

A 7-year-old male presented with right facial weakness in addition to headaches, ataxia, urinary incontinence, and falls. Magnetic resonance imaging revealed CMI with a syrinx of the cervicothoracic spine and syringobulbia. Posterior fossa decompression with duraplasty was performed without complications, and the patient was discharged home on postoperation day 5. At the 3-week follow-up, the patient's neurological deficits had largely subsided. At the 3-month follow-up, his CN VII palsy and syringobulbia had completely resolved.

LESSONS

Pediatric CMI patients with syringomyelia are at risk for developing syringobulbia and brainstem deficits, including unilateral facial palsy. However, craniocervical decompression can prove successful in treating such deficits.

Revision Thoracic Syringo-Subarachnoid Shunt for Recurrent Syrinx With Syringobulbia: Technique and Surgical Video

Syringomyelia and syringobulbia continue to remain a diagnosis without widely accepted treatment paradigms. Furthermore, the currently available treatment options can be complicated by delayed symptom recurrence and the need for revision surgery. Revision intradural surgery is challenging, and currently, there is a paucity of literature describing safe techniques for revision syringotomy and shunt placement. In this technical report, we present a surgical video describing the technique of revision syringo-subarachnoid shunt placement in a 61-year-old female with a history of multiple intradural surgeries who presented with progressively symptomatic ascending syringobulbia. 

Long-term surgical outcome of Chiari type-I malformation-related syringomyelia: an experience of tertiary referral hospital

OBJECTIVE

Syringomyelia is a common condition seen in patients with Chiari type-I malformation (CM1). The purpose of this retrospective study was to evaluate the long-term clinical and radiological outcomes of posterior fossa decompression with duraplasty (PFDD) with coagulation of tonsillar ectopia in consecutive surgically treated adult patients with CM1-related syringomyelia (CRS).

METHODS

Over 9 years' duration (1993-2001), medical charts of diagnosed patient with CM1 at our neurosurgical center were reviewed retrospectively. This study included adult patients with CM1 who had syringomyelia and underwent PFDD with coagulation of tonsillar ectopia surgery. The differences between the pre- and postoperative syrinx/cord ratio (S/C), the syrinx length, and the regression of herniated cerebellar tonsils on coronal and midsagittal MRIs were evaluated.

RESULTS

A total of 87 surgical procedures (46 primary operations, 7 ventriculoperitoneal shunts, and 34 additional operations) for CRS were performed on 24 males and 22 females. The mean preoperative S/C was 0.59 ± 0.12. The means of regression in herniated cerebellar tonsils on mid-sagittal and coronal images were 11.8 ± 2.3 mm and 10.2 ± 2.2 mm (p < 0.0001), respectively. 35 (76.1%) patients were discharged after showing signs of recovery or improvement. Different complications occurred in 16 (34.8%) patients. Negative correlations were noticed between postoperative recovery/improvement and the long symptoms' duration, the herniated tonsils' extent, S/C, and the persistence of the herniated tonsils on the coronal images.

CONCLUSION

Early diagnosis of patients with CRS can improve surgical outcomes. Due to its efficacy in resolving clinical symptoms and syrinx cavities, PFDD is still an optimal surgical approach for CRS.

Syringobulbia in a Setting of Charcot Arthropathy of the Elbow Secondary to Syringomyelia: A Case Report

CASE

The authors present a case of syringobulbia in a setting of elbow arthropathy due to syringomyelia. The patient had painless elbow instability with subtle neurological findings such as ulnar neuropathy, palatal palsy, and dysphonia. As she denied surgery, she was managed with physiotherapy and orthosis. At 24 months of follow-up, she had good clinical outcome without neurological or functional worsening.

CONCLUSION

Many patients with neuropathic joints due to syringomyelia present to an orthopaedician before a neurologist. A high index of suspicion and thorough neurological examination is essential. Conservative management of such a joint provided good results in this patient.

Endoscopic Endonasal Approach for Urgent Decompression of Craniovertebral Junction in Syringobulbia

BACKGROUND

Syringobulbia is an uncommon lesion that occurs in the central nervous system; it is often defined as a pathologic cavitation in the brainstem. The cases with partial blockage of the cerebrospinal fluid pathways at the level of the foramen magnum are more common and the most important group. The most common treatment of syringobulbia is craniovertebral decompression.

CASE DESCRIPTION

This paper reports a case of a symptomatic syringobulbia in which an urgent endoscopic endonasal approach to the craniovertebral junction (CVJ) was done to limit bulbo-medullary compression and rapid neurologic deterioration. A 69-year-old man was admitted to the hospital because of acute onset of dysphonia, dysphagia, imbalance, and vomiting. Magnetic resonance imaging revealed a cystic lesion in the brainstem, suggestive of a syringobulbia in Klippel Feil syndrome with CVJ stenosis.

CONCLUSIONS

This case report details the successful use of endoscopic endonasal anterior decompression to treat syringobulbia, and adds to the growing literature in support of the endonasal endoscopic approach as a safe and feasible means for decompressing the craniocervical junction, even in the setting of urgency. However, prudent patient selection, combined with sound clinical judgment, access to instrumentation, and intraoperative imaging cannot be overemphasized.

Is Cervical Stabilization for All Cases of Chiari-I Malformation an Overkill? Evidence Speaks Louder Than Words!

Chiari I malformation is characterized by the downward displacement of cerebellar tonsils through the foramen magnum. While discussing the treatment options for Chiari I malformation, the points of focus include: (1) Has the well-established procedure of posterior fossa decompression become outdated and has been replaced by posterior C1–2 stabilization in every case? (2) In case posterior stabilization is required, should a C1–2 stabilization, rather than an occipitocervical fusion, be the only procedure recommended? The review of literature revealed that when there is bony instability like atlantoaxial dislocation (AAD), occipito-atlanto-axial facet joint asymmetry or basilar invagination (BI) associated with Chiari I malformation, one should address the anterior bony compression as well as perform stabilization. This takes care of the compromised canal at the foramen magnum and re-establishes the cerebrospinal fluid flow along the craniospinal axis; and also provides treatment for CVJ instability. In the cases with a pure Chiari I malformation without AAD or BI and with completely symmetrical C1–2 joints, however, posterior fossa decompression with or without duroplasty is sufficient to bring about neurological improvement. The latter subset of cases with pure Chiari I malformation have, thus, shown significant (>70%) rates of neurological improvement with posterior fossa decompression alone. A C1–2 posterior stabilization is a more stable construct due to the strong bony purchase provided by the C1–2 lateral masses and the short lever arm of the construct. However, in the cases with significant bleeding from paravertebral venous plexus; a very high BI, condylar hypoplasia and occipitalized atlas; gross C1–2 rotation or vertical C1–2 joints with unilateral C1 or C2 facet hypoplasia, as well as the presence of subaxial scoliosis; maldevelopment of the lateral masses and facet joints (as in very young patients); or, the artery lying just posterior to the C1–2 facet joint capsule (being endangered by the C1–2 stabilization procedure), it may be safer to perform an occipitocervical rather than a C1–2 fusion.

Syringobulbia in Patients with Chiari Malformation Type I: A Systematic Review

This study aimed to summarize the clinical features, diagnosis, and treatment of Chiari malformation type I- (CM-1-) associated syringobulbia. We performed a literature review of CM-1-associated syringobulbia in PubMed, Ovid MEDLINE, and Web of Science databases. Our concerns were the clinical features, radiologic presentations, treatment therapies, and prognoses of CM-1-associated syringobulbia. This review identified 23 articles with 53 cases. Symptoms included headache, neck pain, cranial nerve palsy, limb weakness/dysesthesia, Horner syndrome, ataxia, and respiratory disorders. The most frequently involved area was the medulla. Most of the patients also had syringomyelia. Surgical procedures performed included posterior fossa decompression, foramen magnum decompression, cervical laminectomy, duraplasty, and syringobulbic cavity shunt. Most patients experienced symptom alleviation or resolution postoperatively. A syringobulbic cavity shunt provided good results in refractory cases. Physicians should be aware of the possibility of syringobulbia in CM-1 patients, especially those with symptoms of sudden-onset brain-stem involvement. The diagnosis relies on the disorder's specific symptomatology and magnetic resonance imaging. Our review suggests that the initial therapy should be posterior fossa decomposition with or without duraplasty. In refractory cases, additional syringobulbic cavity shunt is the preferred option.

Signs consistent with syringobulbia may be detected in dogs undergoing MRI

Syringobulbia is a pathologic condition characterized by one or more fluid-filled cavities within the brainstem. This retrospective case series describes observations in eight dogs with syringobulbia diagnosed during MRI. All dogs were adult, small-breed dogs with concurrent syringomyelia and neurologic deficits localized to sites rostral to the spinal cord, which cannot be explained by syringomyelia (eg, six dogs had vestibular signs). On MRI, the fluid-filled cavities had signal intensity characteristics like cerebrospinal fluid, were in the medulla oblongata, and were solitary in each dog. Initially, the shape of the cavity was a slit in five dogs and bulbous in two dogs. Magnetic resonance imaging was repeated in five dogs (6-55 months of age). One dog had progression of syringobulbia from slit-like to bulbous, and four dogs had unchanged slit-like syringobulbia. One dog developed slit-like syringobulbia after cranioplasty. A variety of medical and surgical treatments were performed with improvement of some but not all clinical signs. One dog died following surgery due to cardiopulmonary failure and the other seven dogs were alive at least 1 year after the initial diagnosis, which was the least time of follow-up. One surviving dog developed a unilateral hypoglossal nerve deficit 2 months after the initial diagnosis and megaesophagus 14 months later. In conclusion, detecting a fluid-filled cavity in the medulla oblongata consistent with syringobulbia is possible in dogs undergoing MRI. The cavity is likely acquired, slit-like or bulbous, progressive, or static, and might be associated with breed size and neurologic signs localized to the medulla oblongata.

Syringobulbia: A delayed complication following spinal cord injury - case report

CONTEXT

Syringobulbia is a very rare progressive disorder of central nervous system, with several possible underlying conditions. Rarely, it is also encountered as a late complication of syringomyelia.

FINDINGS

In the present manuscript, a case of a paraplegic patient, due to traumatic spinal cord injury (thoracolumbar fracture), presenting after years progressively developing symptoms of the lower cranial nerves and upper extremities, owed to syringomyelia and syringobulbia, the surgical treatment applied and its outcomes are described. We performed a syringo-peritoneal shunting procedure using a T-tube. The patient's symptoms resolved postoperatively and the cavity's size was reduced to a great degree.

CONCLUSION/CLINICAL RELEVANCE

The late appearance of cranial nerve deficits or symptoms-signs of the upper extremities in a patient with traumatic thoracic spinal cord injury should raise suspicion that post-traumatic syringomyelia or syringobulbia has occurred. In such cases, radiologic evaluation and early surgical drainage of the cyst as a means of preventing significant delayed neurologic deficit is advocated.

Syringobulbia in pediatric patients with Chiari malformation type I

OBJECTIVE Syringobulbia (SB) is a rare entity, with few cases associated with Chiari malformation type I (CM-I) in the pediatric population. The authors reviewed all pediatric cases of CM-I-associated SB managed at their institution in order to better understand the presentation, treatment, and surgical outcomes of this condition. METHODS A prospectively maintained institutional database of craniovertebral junction abnormalities was analyzed to identify all cases of CM-I and SB from the MRI era (i.e., after 1984). The authors recorded presenting symptoms, physical examination findings, radiological findings, surgical treatment strategy, intraoperative findings, and outcomes. SB cases associated with tumors, infections, or type II Chiari malformations were excluded. RESULTS The authors identified 326 pediatric patients with CM-I who were surgically treated. SB was identified in 13 (4%) of these 326 patients. Headache and neck pain were noted in all 13 cases. Cranial nerve abnormalities were common: vagus and glossopharyngeal nerve dysfunction was the most frequent observation. Other cranial nerves affected included the trigeminal, abducens, and hypoglossal nerves. Several patients exhibited multiple cranial nerve palsies at presentation. Central sleep apnea was present in 6 patients. Syringomyelia (SM) was present in all 13 patients. SB involved the medulla in all cases, and extended rostrally into the pons and midbrain in 2 patients; in 1 of these 2 cases the cavity extended further rostrally to the cerebrum (syringocephaly). SB communicated with the fourth ventricle in 7 of the 13 cases. All 13 patients were treated with posterior fossa decompression with intradural exploration to ensure CSF egress out of the fourth ventricle and through the foramen magnum. The foramen of Magendie was found to be occluded by an arachnoid veil in 9 cases. Follow-up evaluation revealed that SB improved before SM. Cranial nerve palsies regressed in 11 of the 13 patients, and SB improved in all 13. CONCLUSIONS The incidence of SB in our surgical series of pediatric patients with CM-I was 4%, and all of these patients had accompanying SM. The SB cavity involved the medulla in all cases and was found to communicate with the fourth ventricle in 54% of cases. Posterior fossa decompression with intradural exploration and duraplasty is an effective treatment for these patients.

Management of parturients in active labor with Arnold Chiari malformation, tonsillar herniation, and syringomyelia

BACKGROUND

Arnold-Chiari malformation Type 1 (ACM-1) in parturients is a topic of ongoing discussion between obstetricians and anesthesiologists. The primary unanswered question remains; How should the anesthesia provider proceed with labor analgesia and anesthesia for cesarean section when confronted with an advanced, asymptomatic, or minimally symptomatic case of ACM-1 during labor?

CASE DESCRIPTION

A 24-year-old, ASA II, G1P0 full-term parturient presented to Labor and Delivery for vaginal delivery. A diagnosis of ACM-1 was made 12 years ago when a brain magnetic resonance imaging (MRI) was performed for right-sided numbness following a rear-end motor vehicle collision. The patient had been asymptomatic since then and had been seen by an outside neurologist frequently for the past 10 years. During the anesthesia evaluation, it was noted that she had an exaggerated patellar reflex, and a questionable left-sided Babinski; subsequently, an MRI study was requested. Review of a brain MRI demonstrated an advanced form of ACM with a 1.7 cm transtonsillar herniation and a large syrinx extending from C1 down to C5. Following a discussion with the patient, family, and primary OB team, a plan for elective cesarean section was made per neurosurgical recommendations. This was conducted uneventfully under general anesthesia. The patient had no complaints in the post-anesthesia care unit.

CONCLUSION

Unfamiliarity of health care providers with regards to ACM-1 parturients can be countered by increasing awareness of this condition throughout medical specialties involved in their care. The Ghaly Obstetric Guide to Arnold-Chiari malformation Type 1, along with proper training of anesthesia care providers regarding the specificities of ACM-1 parturients aids in better management and understanding of this complex condition.

Syringohydromyelia in association with syringobulbia and syringocephaly: case report

The authors present the case of a 14-year-old boy with holocord syringohydromyelia extending into the brainstem, cerebral peduncle, internal capsule, and cerebral cortex. At the posterior fossa exploration, an opaque thickened arachnoid with occlusion of the foramen of Magendie was encountered. Careful documentation of postoperative regression of the syringocephaly, syringobulbia, and syringohydromyelia was made. The pathophysiology is discussed.

Pediatric and adult Chiari malformation Type I surgical series 1965-2013: a review of demographics, operative treatment, and outcomes

OBJECT

Chiari malformation Type I (CM-I) is a hindbrain disorder associated with elongation of the cerebellar tonsils, which descend below the foramen magnum into the spinal canal. It occurs in children and adults. Clinical symptoms mainly develop from alterations in CSF flow at the foramen magnum and the common subsequent development of syringomyelia.

METHODS

The authors reviewed English-language reports of pediatric, adult, and combined (adult and pediatric) surgical series of patients with CM-I published from 1965 through August 31, 2013, to investigate the following: 1) geographical distribution of reports; 2) demographics of patients; 3) follow-up lengths; 4) study durations; 5) spectrum and frequency of surgical techniques; 6) outcomes for neurological status, syrinx, and headache; 7) frequency and scope of complications; 8) mortality rates; and 9) differences between pediatric and adult populations. Research and inclusion criteria were defined, and all series that contained at least 4 cases and all publications with sufficient data for analysis were included.

RESULTS

The authors identified 145 operative series of patients with CM-I, primarily from the United States and Europe, and divided patient ages into 1 of 3 categories: adult (>18 years of age; 27% of the cases), pediatric (≤18 years of age; 30%), or unknown (43%). Most series (76%) were published in the previous 21 years. The median number of patients in the series was 31. The mean duration of the studies was 10 years, and the mean follow-up time was 43 months. The peak ages of presentation in the pediatric studies were 8 years, followed by 9 years, and in the adult series, 41 years, followed by 46 years. The incidence of syringomyelia was 65%. Most of the studies (99%) reported the use of posterior fossa/foramen magnum decompression. In 92%, the dura was opened, and in 65% of these cases, the arachnoid was opened and dissected; tonsillar resection was performed in 27% of these patients. Postoperatively, syringomyelia improved or resolved in 78% of the patients. Most series (80%) reported postoperative neurological outcomes as follows: 75% improved, 17% showed no change, and 9% experienced worsening. Postoperative headaches improved or resolved in 81% of the patients, with a statistical difference in favor of the pediatric series. Postoperative complications were reported for 41% of the series, most commonly with CSF leak, pseudomeningocele, aseptic meningitis, wound infection, meningitis, and neurological deficit, with a mean complication rate of 4.5%. Complications were reported for 37% of pediatric, 20% of adult, and 43% of combined series. Mortality was reported for 11% of the series. No difference in mortality rates was seen between the pediatric and adult series.

CONCLUSIONS

Before undergoing surgical treatment for CM-I, symptomatic patients and their families should be given clear information about the success of treatment and potential complications. Furthermore, surgeons may benefit from comparing published data with their own. In the future, operative CM-I reports should provide all details of each case for the purpose of comparison.

Isolated Post-Traumatic Syringobulbia; Case Report and Review of the Literature

Syringobulbiais very rare condition defined as slit-like fluid cavity in the brain stem. Several conditions have been reported to be associated with syringobulbia including neoplasms, spinal cord traumas or lesions such as tethered cord, hind-brain herniation, infections such as meningitis and in isolation. Although post-traumatic syringomyelia has been wieldy described previously, traumatic brain injury has not been reported as the mechanism and etiology of isolated syringobulbia. We herein report a 24-year old man with previous history of severe traumatic brain injury who presented with recent onset inability to walk or coordinate movements, ataxia, dysphonia, dysarthria, bilateral third nerve palsy with fixed dilated pupils and eyes deviated outward and downward. He was further diagnosed to have isolated syringobulbia extending to upper pons and lower midbrain. Isolated post-traumatic syringobulbia is extremely rare condition presenting insidiously with cranial nerve palsies, ataxia and dysarthria.

Occipitocondylar hyperplasia and syringomyelia presenting with facial pain

The authors describe a unique presentation and long-term management of a rare craniovertebral abnormality in a patient presenting to their institution. This 10-year-old girl presented with right-sided facial pain and subjective dysesthesia of the chest wall without evidence of cervical myelopathy. She was found to have extensive cervicothoracic syringomyelia secondary to compression at the foramen magnum by hypertrophic occipital condyles. Posterior decompression and medial condylectomy was performed, with significant radiological and clinical improvement over the next 5 years of follow-up. The authors discuss the clinical pathophysiology and operative techniques used.

Delamination technique together with longitudinal incisions for treatment of Chiari I/syringomyelia complex: a prospective clinical study

Background

Treatment modalities in Chiari malformation type 1(CMI) accompanied by syringomyelia have not yet been standardized. Pathologies such as a small posterior fossa and thickened dura mater have been discussed previously. Various techniques have been explored to enlarge the foramen magnum and to expand the dura. The aim of this clinical study was to explore a new technique of excision of the external dura accompanied by widening the cisterna magna and making longitudinal incisions in the internal dura, without disturbing the arachnoid.

Methods

Ten patients with CMI and syringomyelia, operated between 2004 and 2006, formed this prospective series. All cases underwent foramen magnum decompression of 3 × 3 cm area with C1–C2 (partial) laminectomy, resection of foramen magnum fibrous band, excision of external dura, delamination and widening of internal dura with longitudinal incisions.

Results

Patients were aged between 25 and 58 years and occipital headache was the most common complaint. The mean duration of preoperative symptoms was 4 years and the follow-up time was 25 months. Clinical progression was halted for all patients; eight patients completely recovered and two reported no change. In one patient, there was a transient cerebrospinal fluid (CSF) fistula that was treated with tissue adhesive. While syringomyelia persisted radiologically with radiological stability in five patients; for three patients the syringomyelic cavity decreased in size, and for the remaining two it regressed completely.

Conclusion

Removal of the fibrous band and the outer dural layer, at level of foramen magnum, together with the incision of inner dural layer appears to be good technique in adult CMI patients. The advantages are short operation time, no need for duraplasty, sufficient posterior fossa decompression, absence of CSF fistulas as a result of extra arachnoidal surgery, and short duration of hospitalization. Hence this surgical technique has advantages compared to other techniques.

Morphometric analysis of the craniocervical juncture in children with Chiari I malformation and concomitant syringobulbia

INTRODUCTION

Although very uncommon, Chiari I malformation (CIM) with syringomyelia may be associated with concomitant syringobulbia. We hypothesized that the anatomy of the craniocervical region may be different in CIM patients with syringomyelia who develop syringobulbia in conjunction with their syringomyelia compared to other patients with CIM with and without syringomyelia. The present study was conducted in order to prove or disprove such a theory.

MATERIALS AND METHODS

A group of 189 children with operated CIM were reviewed for the presence of syringobulbia, and this cohort then underwent morphometric analyses of their craniocervical juncture. These measurements were then compared to both our prior patient findings and historic controls.

RESULTS

The current study did not identify any morphometrical peculiarities for patients with CIM and syringobulbia compared to other CIM patients with and without isolated syringomyelia.

CONCLUSIONS

Based on our study, the mechanism behind such cerebrospinal fluid distention into the brain stem remains elusive with no single morphometrical difference in patients with CIM and syringobulbia compared to other patients with CIM. Perhaps, future testing aimed at identifying pressure gradients across the foramen magnum in patients with and without syringobulbia and concomitant CIM may be useful.

Long-term follow-up of Chiari-related syringomyelia in adults: analysis of 157 surgically treated cases

OBJECTIVE

To determine the long-term outcome of surgically treated Chiari-related syringomyelia.

METHODS

The medical charts of 157 consecutive surgically treated patients with Chiari-related syringomyelia were retrospectively analyzed. Factors predicting outcome, either clinical or radiological, are discussed, and our results are compared with those of other large series in the literature.

RESULTS

The study included 74 men and 83 women (age range, 16-75 years; mean age at surgery, 38.3 years). Pain and sensory disturbance were the most frequent initial symptoms. The average duration of preoperative symptoms was 8.2 years. The follow-up period ranged from 82 to 204 months (median, 88 months). At the end of the study, 99 patients (63.06%) had improved, 48 (30.58%) had stabilized, 9 (5.73%) had worsened, and 1 (0.63%) had died during the postoperative period. Factors predicting improvement or stabilization were young age at the time of surgery and clinical signs of paroxysmal intracranial hypertension. Factors associated with a poor outcome were older age at the time of surgery, arachnoiditis, and a clinical feature of long-tract impairment syndrome. The presence of arachnoiditis or of basilar invagination was associated with poor clinical presentation (P = 0.05 and 0.0001, respectively). The extent of the cyst on postoperative magnetic resonance imaging was a predictor of poor clinical outcome (P = 0.002).

CONCLUSION

Our results confirmed that surgery is an effective and safe treatment of Chiari-related syringomyelia, with a 90% chance of long-term stabilization or improvement on average. Surgery should be proposed as soon as possible in patients with clearly progressing clinical features.

Syringobulbia in a Pediatric Population

OBJECTIVE:

To better understand the presentation, management, and outcome of syringobulbia in the pediatric age group.

METHODS:

The University of Iowa pediatric neurosurgery database was searched for patients under the age of 18 with a diagnosis of syringobulbia. The patients' records were retrospectively reviewed for demographic data, chief complaint and presenting symptoms, neurological and radiographic findings, treatment, outcome, and complications. Children with open neural tube defects and Chiari II malformations were excluded.

RESULTS:

Six pediatric patients were identified as meeting inclusion criteria. The average age at time of surgery was 14.8 years. The chief complaints were vision impairment in three children and numbness, gait instability, and headache worsened with Valsalva in one patient each. Other prominent symptoms included sleep apnea and weakness. All patients showed at least one cranial nerve dysfunction. Radiographs revealed hindbrain herniation and associated syringomyelia in all cases. Two patients had scoliosis. Treatment was posterior fossa decompression with cerebellar tonsillar shrinkage, opening of foramen of Magendie, and duraplasty. Two patients also required concomitant ventral decompression. The cavity of syringobulbia communicated with syringomyelia and the fourth ventricle in most children but was distinct from the fourth ventricle. Two patients received fourth ventricle to subarachnoid shunts. Follow-up averaged 3.2 years, and all patients clinically improved after surgery. Magnetic resonance imaging documented resolution of syringobulbia in all cases, with syringomyelia improving in all cases. There was no permanent morbidity or mortality in the series.

CONCLUSION:

Syringobulbia is strongly associated with Chiari malformation and syringomyelia, and patients often present because of cranial nerve palsies. Posterior fossa decompression is a safe and effective treatment.

Syringocephaly

Syringomyelia is associated with Arnold-Chiari Type I malformations. Syringobulbia describes the phenomenon of syrinx extension into the brain stem. Syringocephaly is the further dissection of the fluid-filled cavity into the cerebral peduncles and cerebrum. In this case report, we describe a patient who presented with bulbar, sensory, motor, and coordination deficits both ipsilateral and contralateral to the lesion. This is most likely attributable to the wandering course the syrinx takes as it dissects through the spinal cord and into the internal capsule. This ill-defined syrinx disrupts various nuclei and fasciculi, both pre- and post-decussation, thus explaining the multiple deficits on each side. We initially treated this patient with a suboccipital craniectomy, C1 laminectomy, and duraplasty, which mildly improved his deficits. During follow-up, the patient was then found to have an exacerbation of his symptoms, at which time we performed a VP shunt revision (the patient had a history of hydrocephalus treated by a functioning VP shunt). Approximately 2 weeks after revision of the VP shunt, the patient had worsening of his symptoms, which we treated with a syringopleural shunt. This proved to be the most effective treatment with the greatest clinical improvement. Several months later, however, the patient died secondary to pulmonary disease exacerbated by VP shunt infection. In this paper, we also review the literature regarding the formation and treatment of syringocephaly, a rare and poorly understood entity.

Syringomyelia with syringobulbia presenting only with paralysis of 9th and 10th cranial nerves

We report a case of syringomyelia with syringobulbia, in a patient who presented only with involvement of the 9th and 10th cranial nerves.

The trigeminal nerve

The trigeminal nerve is the largest of the cranial nerves, serving as a major conduit for sensory information from the head and neck and primarily providing motor innervation to the muscles of mastication. An understanding of the pathologic processes that may involve this nerve requires a detailed knowledge of its origin within the brain stem as well as its course intracranially. This article describes the neuroanatomy of the nerve and divides it into its various segments to provide a differential diagnosis of common and some uncommon pathologic processes.

Ocular manifestations of hindbrain-related syringomyelia and outcome following craniovertebral decompression

PURPOSE

To analyse and evaluate associated ocular symptoms and signs in hindbrain-related syringomyelia and their response to treatment.

METHODS

From a database of 275 patients treated in a single institution for hindbrain hernia and syringomyelia, 39 patients (14%) had ocular symptoms and signs. Only 31 patients were included in this study; the remainder were excluded due to inadequate follow-up information. All patients had confirmed evidence of hindbrain-related syringomyelia with MRI scan or CT myelogram. Treatment included craniovertebral decompression or ventriculo-peritoneal shunting. The mean follow-up was 23 months.

RESULTS

In addition to the well-recognised sign of downbeat nystagmus, classically associated with foramen magnum abnormalities, a number of other ophthalmic features were identified. Symptoms included diplopia, oscillopsia, tunnel vision and difficulty in lateral gaze. Signs included nystagmus (downbeat, horizontal, rotatory, and combinations), strabismus, disc pallor, anisocoria, ptosis and field defect. Patients were categorised into two groups depending on whether the ocular features were manifest at first presentation (group 1, n = 14) or developed later in the course of the disease (group 2, n = 17). The delay in diagnosis from first presentation was 5 and 6 years respectively. All patients underwent surgery. Craniovertebral decompression was performed in 13 patients in group 1 and in 15 patients in group 2. Ventriculo-peritoneal shunt was inserted in 1 patient in group 1 and in 3 patients in group 2, for the associated hydrocephalus. Following surgery, 100% of patients in group 1 and 82% of patients in group 2 had complete or partial resolution of their ocular symptoms and signs.

CONCLUSIONS

The presence of unexplained ophthalmic features such as nystagmus or oscillopsia should alert one to the potential diagnosis of hindbrain-related syringomyelia. Delay in diagnosis is often associated with poorer outcome. Surgical treatment can offer excellent results for these patients.

Effects of posterior fossa decompression with and without duraplasty on Chiari malformation-associated hydromyelia

OBJECTIVE

The optimal surgical treatment of Chiari malformation is unclear, especially in patients with hydromyelia. Various surgical approaches have included suboccipital craniectomy, syringostomy, obex plugging, syringosubarachnoid shunting, and fourth ventriculosubarachnoid shunting. The purpose of this study is to differentiate extradural and intradural approaches in the treatment of Chiari I malformation.

METHODS

We reviewed the medical records and magnetic resonance imaging (MRI) scans of 34 surgical corrections' of Chiari malformation performed at our institution from 1988 to 1998. The age and sex of the patient, the presence of hydromyelia, the type of surgery (duraplasty or nonduraplasty), and the clinical outcome were determined.

RESULTS

Eleven patients underwent posterior fossa decompression (PFD) and C1 laminectomy without duraplasty. Eight (73%) of these patients had an improvement in symptoms. Seven of the 11 patients had hydromyelia. Of the six patients who underwent follow-up MRI, three (50%) had a decrease in the size of the hydromyelia, and all three had clinical improvement. We also noted a morphometric increase in posterior fossa volume on postoperative MRI scans in these three patients, which was not observed in those without improvement. Two of the three patients whose hydromyelia did not decrease on follow-up MRI scans worsened clinically, and one underwent a reoperation with duraplasty. Twenty-three patients underwent combined PFD, C1 laminectomy, and duraplasty. Twenty (87%) of these patients had improvement. Twelve of the patients who underwent duraplasty had hydromyelia; nine underwent follow-up MRI. All nine of these patients (100%) had a decrease in the cavity size, including eight with clinical improvement. There were 10 minor complications (seroma, 4; superficial infection, 3; cerebrospinal fluid leak, 2; aseptic meningitis and occipital nerve pain, 1) when the dura was opened, compared with one superficial wound infection that resolved in patients who underwent PFD only.

CONCLUSION

PFD, C1 laminectomy, and duraplasty for the treatment of Chiari I malformation may lead to a more reliable reduction in the volume of concomitant hydromyelia, compared with PFD and C1 laminectomy alone. However, there seems to be a subset of patients whose symptoms will resolve and whose hydromyelic cavity will decrease with the removal of bone only. These patients seem to undergo a volumetric increase in the posterior fossa. Further studies are needed to better characterize these patients, to determine which patients with Chiari I malformation are better served with bony decompression only, and which will require duraplasty to resolve their hydromyelia.

Phase-contrast MR imaging of the cervical CSF and spinal cord: volumetric motion analysis in patients with Chiari I malformation

BACKGROUND AND PURPOSE

Most previous MR studies of the dynamics of Chiari I malformation have been confined to sagittal images and operator-dependent measurement points in the midline. To obtain a deeper insight into the pathophysiology of the Chiari I malformation, we performed a prospective study using axial slices at the level of C2 to analyze volumetric motion data of the spinal cord and CSF over the whole cross-sectional area.

METHODS

Eighteen patients with Chiari I malformation and 18 healthy control subjects underwent cardiac-gated phase-contrast imaging. Cross-sectional area measurements and volumetric flow/motion data calculations were made for the following compartments: the entire intradural space, the spinal cord, and the anterior and posterior subarachnoid space.

RESULTS

The most striking feature was an increased early systolic caudal and diastolic cranial motion of the spinal cord in the patients. CSF pulsations in the anterior subarachnoid space were unchanged at systole but showed an impaired diastolic upward flow. In the posterior compartment, the CSF systole was slightly shortened, with an impairment of diastolic upward flow. Fourteen of the 18 patients had associated syringeal cavities. This subgroup showed an increased systolic downward displacement of the cord as compared with patients without a syrinx.

CONCLUSION

Obstruction of the foramen magnum in patients with Chiari I malformation causes an abrupt systolic downward displacement of the spinal cord and impairs the recoil of CSF during diastole.

Tinnitus as the presenting symptom in a case of Lhermitte-Duclos disease

Dysplastic gangliocytoma or Lhermitte-Duclos disease (LDD) is a hamartomatous malformation of the cerebellar hemisphere that usually presents with signs of increased intracranial pressure or symptoms of cerebellar dysfunction. In this paper, we report a case of LDD presenting with tinnitus, and postulate a probable mechanism for this unusual presentation.

Hypoglossal nerve injury caused by halo-suspension traction. A case report

STUDY DESIGN

A case report of injury to the hypoglossal nerve (CN XII) resulting from the use of halogravity traction in a child with severe cervicothoracic kyphosis after an anterior and posterior spinal release.

OBJECTIVE

To describe one of the potential dangers of halo-suspension (gravity) traction, which has not been reported previously in the orthopedic literature.

SUMMARY OF BACKGROUND DATA

Cranial nerve injuries resulting from halo-skeletal traction are a recognized complication of such treatment, especially in patients with myelomeningocele. Halo-suspension traction using the patient's body weight as counter-traction has been recommended to provide a less rigid force and to reduce complications.

METHODS

The authors report on the mechanism of injury and clinical course in a 12-year-old boy with myelomeningocele and a bilateral CN XII injury caused by halo-suspension traction from onset to resolution.

RESULTS

This patient had dysphagia and difficulty swallowing 5 days after surgery. His wheelchair traction at this point was approximately 40% of his body weight. The traction was reduced, and a corticosteroid was administered. The patient's symptoms began to abate 5 days later. At 6 weeks after injury, his cranial nerve function was normal.

CONCLUSIONS

Although halo-suspension traction or halo-wheelchair traction may be less rigid, injury to the hypoglossal nerve can be produced with traction exceeding 40% of body weight. In the patient in the current report, resolution of this injury was complete within 5 weeks, an outcome that is consistent with those of other reported cases of CN XII injury.

Duraplasty with freeze-dried cadaveric dura versus occipital pericranium for Chiari type I malformation: comparative study

During the period from October 1, 1989 to October 1, 1995 a total of 26 cases of Chiari type I malformation not associated with syringomyelia were attended in our Hospital. All patients underwent cranio-cervical decompression, with occipital craniectomy and removal of the posterior arch of C1. In 3/26 (11.5%) cases an additional C2 laminectomy had to be performed and in 1/26 (3.8%) case the C3 laminae were also removed. A first group of 13 patients underwent dural repair with freeze-dried cadaveric dura sutured with continuous 4-0 Vicryl running stitches, reinforced with fibrin sealant (Tissucol). A second group of 13 patients underwent duraplasty with autogenous occipital pericranium also sutured with continuous 4-0 Vycril but no fibrin sealant at all was added. In the first group, in which freeze-dried cadaveric dura plus Tissucol was used, there were 2/13 (15.3%) cases of CSF leak, requiring some additional skin stitches to stop the leak. In 5/13 (38.4%) cases there were notorious subcutaneous CSF accumulations that required repeated punctures plus compressive bandage. In 6/13 (46.1%) pseudomeningoceles appeared that took a year to clear completely. In the 13 patients who underwent dural repair with autogenous occipital pericranium watertight closure was achieved with sutures only, no fibrin sealant was added at all. Neither CSF leaks through the wound nor subcutaneous CSF accumulations were noted. We conclude that, in our hands, autologous pericranium taken from the occipital area, gives better results than freeze-dried cadaveric dura mater in duraplasty for surgical repair of Chiari type I malformation.

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

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 new cisterna magna of adequate size. Postoperative MRI scans showed an ascent of the cerebellum of 4.3 +/- 4.8 mm (measured by the fastigium 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 cisterna 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 the posterior fossa often results in failures of treatment and recurrences. Tonsillar removal is not necessary to obtain a good reconstruction of the cisterna magna.

The cystic spinal cord

Images

Posterior fossa reconstruction: a surgical technique for the treatment of Chiari I malformation and Chiari I/syringomyelia complex--preliminary results and magnetic resonance imaging quantitative assessment of hindbrain migration

Experimental models have shown that Chiari I malformation is a primary paraaxial mesodermal insufficiency occurring after the closure of the neural folds takes place. According to these hypotheses, a small posterior fossa caused by an underdeveloped occipital bone would be the primary factor in the formation of the hindbrain hernia. The main objective in the surgical treatment of Chiari I malformation and related syringomyelia is directed to restore normal cerebrospinal fluid dynamics at the craniovertebral junction. The most widely accepted surgical approach is to perform a craniovertebral decompression of the posterior fossa contents with or without a dural graft. It has been emphasized that suboccipital craniectomy should be small enough to avoid downward migration of the hindbrain into the craniectomy. This slump of the hindbrain has been verified by studies using postoperative assessment by magnetic resonance imaging. Our aim in this study is to present a modification of the conventional surgical technique, which we have called posterior fossa reconstruction (PFR). Ten patients were operated on using this technique and compared with a historical control group operated on with the classic approach of making a small suboccipital craniectomy, opening the arachnoid, and closing the dura with a graft. To evaluate the morphological results in both groups objectively, preoperative and postoperative measurements of the relative positions of the fastigium and upper pons above a basal line in the midsagittal T1-weighted magnetic resonance images were obtained. In those cases with syringomyelia, syringo-to-cord ratios were calculated. The mean age of the PFR group was 35 +/- 16 years (mean +/- SD); in the control group it was 35.2 +/- 12 years. In the PFR group, the formation of an artificial cisterna magna was observed in every case; it was observed in only one case in the control group. An upward migration of the cerebellum was seen in all cases in the PFR group, with a mean ascent of the fastigium of 6.2 mm. A significant downward migration of the cerebellum was observed in seven cases in the control group. No significant differences were found in both groups when comparing syringo-to-cord ratios. This leads us to conclude that PFR is more effective than conventional surgical approaches in restoring the normal morphology of the craniovertebral junction. This allows cranial ascent of the hindbrain verified by magnetic resonance imaging and good short-term clinical results. Because PFR is mainly an extraarachnoidal approach, complications related to surgery using this technique can be kept to a minimum.

Valvular factors in hydrocephalus

Various ways in which blockage of cerebrospinal fluid pathways can lead to increasing intracranial pressure and enlargement of the ventricles are discussed. The necessity of understanding the valvular morphology involved is stressed as fundamental to the search for optimal treatment methods.

Surgery for hindbrain related syringomyelia

Syringomyelia is a condition with many possible causes, the commonest of which seems to be an abnormality at the foramen magnum. Such cases may be grouped under the heading of "Hindbrain related syringomyelia" and the principles of treatment for all such cases are largely similar. The commonest of these foramen magnum region abnormalities is hindbrain herniation which may be associated with a history of birth difficulties, a small posterior fossa, segmentation abnormalities of the cervical vertebrae or the base of the skull, arachnoiditis of the subarachnoid spaces, subarachnoid pouches, hydrocephalus and intracranial tumours or tumours partly blocking the foramen magnum. Other causes of syringomyelia include conditions which could be grouped under the heading of "non-hindbrain related syringomyelia", these mostly produce blockage of the spinal subarachnoid spaces, especially spinal "arachnoiditis" or meningeal fibrosis, including that secondary to traumatic paraplegia. Intraspinal tumours are sometimes cystic and some authors have included this association under the heading of syringomyelia. Syringomyelia of all kinds is almost always a surgical condition, the destructive forces are those of fluid distending the tissues. As a principle, treatment directed against the cause of the accumulation and the intracord propagation of the fluid by normalising the CSF pathways is more likely to be successful than drainage of the cavities. Drainage operations have an inevitable failure rate and a further incidence of complications attends myelotomy and the leaving of any drainage tube within the narrow confines of the spine. Correction of craniospinal pressure dissociation and re-establishment of a cisterna magna appears to be the most successful treatment strategy and is likely to be immediately and permanently successful in correcting not only the pressure problems such as long tract involvement and syringobulbia features but also in producing satisfactory clinical and radiological improvement in the syringomyelia. The recommended technique includes radical means to gain space at the foramen magnum by creating a large artificial cisterna magna, resecting part of the tonsils, preventing the descent of the cerebellum and avoiding the use of space occupying or fibrosis producing dural grafts. Because the pathogenesis of the cavities remains in doubt, the method by which this treatment stratagem is effective is unclear. It may be that change in the closure conditions of parts of the neuraxis, i.e., alteration in the capacitance and consequent change in pulsation characteristics afforded by the decompression may be the factor which predicates success. Surgical management of hindbrain related syringomyelia is not easy, there are hazards associated with operation, hydrocephalus demands priority in it's management.(ABSTRACT TRUNCATED AT 400 WORDS)