Syringomyelia in association with tumours of the posterior fossa. Pathophysiological considerations, based on observations on three related cases

Management of syringomyelia associated with tuberculous meningitis: A case report and systematic review of the literature

Determinants of tuberculosis (TB) syringomyelia, its management options and outcomes are still under investigation. The aim of this study is to present a case of TB syringomyelia with markedly improved symptoms status-post surgery and to understand the clinical characteristics and outcomes of 33 TB syringomyelia cases reported in the literature. Specifically, we examined the differences between patients who were managed medically and those who underwent surgical intervention. Inclusion criteria for the cases were (1) syringomyelia caused by TB infection rather than co-occurrence of these conditions, (2) management protocol described, and (3) post-treatment outcome described. The median age was 30 years (interquartile range (IQR): 23-40) with 55% males. The median time between TB onset to syringomyelia diagnosis was 2 years. Nineteen patients were surgically treated, 11 were medically treated, and 3 received no treatment. Twenty-one patients showed improvement in at least one prior symptom, but no patient experienced a full recovery. Those that underwent surgical intervention were more likely to have TB meningitis (95% vs. 64%, p < 0.05) upon initial TB presentation and have a greater interval between TB onset and syringomyelia presentation (median of 2.6 vs. 0.33 years, ns). A greater proportion of the surgically managed patients experienced improvement in any symptom (74% vs. 45%, ns). Future case-controlled studies with larger sample sizes are required to validate and further understand the outcomes of surgically-managed TB syringomyelia.

Cystic Degeneration of Cerebellar Tonsil 1 Year After Chiari I Malformation Surgery: A Case Report and Review of the Literature

BACKGROUND

Chiari malformation results from a bony structural anomaly of the skull base. The structural defect causes downward displacement of the cerebellar tonsils through the foramen magnum. The herniated tonsils block the normal flow of cerebrospinal fluid, which causes a wide spectrum of clinical symptoms.

CASE REPORT

In May 2015, a 16-year-old girl was referred to our center because of a 1-year history of occipital headache, most often triggered by exercise and physical activity at school. She had experienced new-onset numbness in both hands, more severe on the right side, associated with some degrees of weakness. Eventually, an evaluation of her condition included magnetic resonance imaging in T1 and T2 sequences, which revealed a 20-mm downward migration of the cerebellar tonsils, associated with a cervical cord syrinx at the level of the fourth and fifth cervical vertebrae. The patient underwent posterior fossa decompression and C1 and partial C2 laminectomies. Postoperatively there were no complications, and the patient was discharged on day 3. Postoperatively, she experienced some improvement in her symptoms. After 2 months of routine outpatient follow-up, she was better, the headaches had subsided, she could resume some activities, and there was no paresis in her limbs.

CONCLUSIONS

In cases of progressive symptoms of Chiari malformation, surgical decompression is important and should be considered after shunt insertion to the hindbrain.

Syringobulbia associated with posterior fossa meningioma: a review of the literature

PURPOSE

Syringomyelia can be defined as a degenerative, progressive and chronic spinal cord disease. Its association with tumors of the posterior cranial fossa (PCF) is a rare condition.

METHODS

The authors report a rare case of syringobulbia consequent to a meningioma originating from PCF in a 17-year-old female, discussing the pathogenetic mechanism of development and the resolution of the syrinx cavity after surgical procedure.

RESULTS

The postoperative period was uneventful without complications. At 6-month follow-up, MRI revealed complete tumor removal with resolution of the syrinx cavity.

CONCLUSIONS

In cases of syringomyelia and tonsillar herniation associated with PCF meningioma, the tumor resection allows to eliminate the mass effect and increases the size of the posterior fossa with the progressive ascent of the cerebellar tonsils and the consequent reduction of their downward movement with systolic pulsation. The re-establishment of a normal anatomical condition led to the gradual disappearance of syrinx and hydrocephalus.

Arachnolysis or cerebrospinal fluid diversion for adult-onset syringomyelia? A Systematic review of the literature

OBJECTIVE

To identify surgical practice patterns in the literature for nonpediatric syringomyelia by systematic review and to determine the following: 1) What is the best clinical practice of cerebrospinal fluid (CSF) diversion to maximize clinical improvement or to achieve the lowest recurrence rate? 2) Does arachnolysis, rather than CSF diversion, lead to prolonged times to clinical recurrence?

METHODS

A database search comprising PubMed, Cochrane Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Cochrane Database of Systematic Reviews was conducted to find pertinent articles on postinfectious, posttraumatic, or idiopathic syringomyelia.

RESULTS

An advanced PubMed search in August 2012 yielded 1350 studies, including 12 studies meeting Oxford Centre for Evidence-Based Medicine criteria for level IV evidence as a case series, with a total of 410 patients (mean age, 39 years). Data on 486 surgeries were collected. Mean follow-up data were available for 10 studies, with a mean follow-up time of 62 months. On regression analysis, increased age had a significant correlation with a higher likelihood of having clinically significant recurrence on mean follow-up (P < 0.05). The use of arachnolysis in surgery was associated with a longer duration until clinically symptomatic recurrence (P = 0.02). Data on mortality were unavailable. The mean number of surgeries per patient across all studies was 1.20 (range, 0.95-2.00).

CONCLUSIONS

With postinfectious and posttraumatic etiologies, arachnolysis was the only surgical treatment to have a statistically significant effect on decreasing recurrence rates. More prospective, randomized, controlled studies are required to reach a clear consensus.

Adult medulloblastoma associated with syringomyelia: a case report

The association between cerebellar medulloblastoma and syringomyelia is uncommon and only found in pediatric patients. To date, adult medulloblastoma associated with syringomyelia has not been reported in the literature. Paroxysmal bradycardia is an uncommon clinical manifestation in posterior fossa tumors and likely to be vagally mediated via brainstem preganglionic cardiac motor neurons. This report introduces the diagnosis and treatment of a case of adult medulloblastoma associated with syringomyelia, which presented with paroxysmal bradycardia.

Cervicothoracic syringohydromyelia associated with a prosencephalic mass in a dog

A five-year-old, female, neutered boxer, with neuroanatomical signs consistent with a C1-C5 myelopathy, was diagnosed with a prosencephalic mass and associated severe cervicothoracic syringohydromyelia. After treatment with corticosteroids and lomustine, neurological examination was normal. Imaging repeated three months later showed significant reduction in both the size of the mass and the syringohydromyelia. To the authors' knowledge, this is the first reported case of a dog with syringohydromyelia secondary to a rostral brain mass that had clinical signs on presentation solely due to the syrinx, and the first reported case in a dog of partial resolution of syringohydromyelia after treatment solely with chemotherapy.

Treatment of posttraumatic syringomyelia

Object

This paper presents results of a prospective study for patients undergoing surgery for posttraumatic syringomyelia between 1991 and 2010.

Methods

A group of 137 patients with posttraumatic syringomyelia were evaluated (mean age 45 ± 13 years, mean follow-up 51 ± 51 months) with pre- and postoperative MRI and clinical examinations presenting in this period and followed prospectively by outpatient visits and questionnaires. Surgery was recommended for symptomatic patients with a progressive course. Short-term results were determined within 3 months of surgery, whereas long-term outcomes in terms of clinical recurrences were studied with Kaplan-Meier statistics.

Results

Three groups were distinguished according to the type of trauma: Group A, patients with spinal trauma but without cord injury (ASIA E, n = 37); Group B, patients with an incomplete cord injury (ASIA C or D, n = 55); and Group C, patients with complete loss of motor function or a complete cord injury (ASIA A or B, n = 45). Overall, 61 patients with progressive symptoms underwent 71 operations. Of these operations, 61 consisted of arachnolysis, untethering, and duraplasty at the trauma level (that is, decompression), while 4 ASIA A patients underwent a cordectomy. The remaining procedures consisted of placement of a thecoperitoneal shunt, 2 opiate pump placements, and 2 anterior and 1 posterior cervical decompression and fusion. Seventy-six patients were not treated surgically due to lack of neurological progression or refusal of an operation. Neurological symptoms remained stable for 10 years in 84% of the patients for whom surgery was not recommended due to lack of neurological progression. In contrast, 60% of those who declined recommended surgery had neurological progression within 5 years. For patients presenting with neurological progression, outcome was better with decompression. Postoperatively, 61% demonstrated a reduction of syrinx size. Although neurological symptoms generally remained unchanged after surgery, 47% of affected patients reported a postoperative improvement of their pain syndrome. After 3 months, 51% considered their postoperative status improved and 41% considered it unchanged. In the long-term, favorable results were obtained for Groups A and C with rates for neurological deterioration of 6% and 14% after 5 years, respectively. In Group B, this rate was considerably higher at 39%, because arachnolysis and untethering to preserve residual cord function could not be fully achieved in all patients. Cordectomy led to neurological improvement and syrinx collapse in all 4 patients.

Conclusions

The technique of decompression with arachnolysis, untethering, and duraplasty at the level of the underlying trauma provides good long-term results for patients with progressive neurological symptoms following ASIA A, B and E injuries. Treatment of patients with posttraumatic syringomyelia after spinal cord injuries with preserved motor functions (ASIA C and D) remains a major challenge. Future studies will have to establish whether thecoperitoneal shunts would be a superior alternative for this subgroup.

Foramen magnum arachnoid cyst induces compression of the spinal cord and syringomyelia: case report and literature review

It is very rare that a foramen magnum arachnoid cyst induces compression of the spinal cord and syringomyelia, and currently there are few treatment experiences available. Here we reported the case of a 43-year-old male patient who admitted to the hospital due to weakness and numbness of all 4 limbs, with difficulty in urination and bowel movement. MRI revealed a foramen magnum arachnoid cyst with associated syringomyelia. Posterior fossa decompression and arachnoid cyst excision were performed. Decompression was fully undertaken during surgery; however, only the posterior wall of the arachnoid cyst was excised, because it was almost impossible to remove the whole arachnoid cyst due to toughness of the cyst and tight adhesion to the spinal cord. Three months after the surgery, MRI showed a reduction in the size of the arachnoid cyst but syrinx still remained. Despite this, the symptoms of the patient were obviously improved compared to before surgery. Thus, for the treatment of foramen magnum arachnoid cyst with compression of the spinal cord and syringomyelia, if the arachnoid cyst could not be completely excised, excision should be performed as much as possible with complete decompression of the posterior fossa, which could result in a satisfying outcome.

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

Chiari disease (or malformation) is in general a congenital condition characterized by an anatomic defect of the base of the skull, in which the cerebellum and brain stem herniate through the foramen magnum into the cervical spinal canal. The onset of Chiari syndrome symptoms usually occurs in the second or third decade (age 25 to 45 years). Symptoms may vary between periods of exacerbation and remission. The diagnosis of Chiari type I malformation in patients with or without symptoms is established with neuroimaging techniques. The most effective therapy for patients with Chiari type I malformation/syringomyelia is surgical decompression of the foramen magnum, however there are non-surgical therapy to relieve neuropathic pain: either pharmacological and non-pharmacological. Pharmacological therapy use drugs that act on different components of pain. Non-pharmacological therapies are primarily based on spinal or peripheral electrical stimulation. It is important to determine the needs of the patients in terms of health-care, social, educational, occupational, and relationship issues, in addition to those derived from information aspects, particularly at onset of symptoms. Currently, there is no consensus among the specialists regarding the etiology of the disease or how to approach, monitor, follow-up, and treat the condition. It is necessary that the physicians involved in the care of people with this condition comprehensively approach the management and follow-up of the patients, and that they organize interdisciplinary teams including all the professionals that can help to increase the quality of life of patients.

Symptomatic syringomyelia occurring as a late complication of posterior fossa medulloblastoma removal in infancy in a boy also suffering from scaphocephaly

INTRODUCTION

The association of a medulloblastoma and a syringomyelia has been already described in rare instances albeit without symptoms related to the syrinx.

CASE REPORT

The case of a 23-year-old man operated in infancy for a medulloblastoma and then treated solely with adjuvant chemotherapy is reported. He was also operated in infancy for a scaphocephaly. With a very long time delay, he has developed a Chiari I and a symptomatic cervico-dorsal syringomyelia. The symptoms attributed to the syrinx consisted of a unilateral prurigo over the left arm which was so severe to lead to self-mutilation.

DISCUSSION

Clinical and magnetic resonance imaging follow-up after cervico-dorsal decompression shows a significant improvement of the symptoms together with a reduction of the size of the syrinx. This case is discussed in the light of the presumed pathophysiology of the syrinx and its exceptional clinical presentation.

Syringopleural shunt as a rescue procedure in patients with syringomyelia refractory to restoration of cerebrospinal fluid flow

OBJECTIVE

Syringomyelia should be treated by reconstruction of the subarachnoid space and restoration of cerebrospinal fluid homeostasis. Direct intervention on the syrinx is a difficult choice and should be considered a rescue procedure. Data in the literature examining the various options are scanty, with generally unsatisfying results. We report our experience with shunting of the syrinx into the pleural space.

METHODS

Twenty patients with syringomyelia refractory to cerebrospinal fluid flow restoration underwent a procedure for placement of a syringopleural shunt between 1998 and 2008. Modified Japanese Orthopaedic Association Scale scores and magnetic resonance imaging were available for each patient preoperatively and at the latest follow-up evaluation. A 2-tailed Wilcoxon signed-rank test was used for statistical analysis. Complications related to the operative procedure and to hardware failure were noted.

RESULTS

Nineteen patients were available for follow-up with a mean duration of 37.5 (standard deviation, 31.1) months. The condition of 1 patient deteriorated, 2 remained stable, and the remainder improved. The overall mean improvement on the Modified Japanese Orthopaedic Association Scale was 19.5% (95% confidence interval, 8.5-30.5). The median improvement was 4 points on the 17-point scale. Results were statistically significant (P < 0.001). Follow-up magnetic resonance imaging showed syrinx collapse in 17 cases and marked shrinkage in 2 cases. Except for 1 case of meningitis followed by fatal pulmonary embolism, no significant complications were noted.

CONCLUSION

A syringopleural shunt should, in our view, be the syrinx diversion procedure of choice. More series of institutional experiences with a homogeneous approach would be helpful to verify this recommendation.

Immediate resolution of tonsillar herniation and severe cervicothoracic syringomyelia after third ventriculostomy for hydrocephalus caused by a brainstem tumor

The authors report the case of a patient who harbored a large intrinsic brainstem tumor associated with tonsillar herniation, hydrocephalus, and severe cervicothoracic syringomyelia. This 15-year-old girl had a 2-month history of progressively worsening headaches. Magnetic resonance imaging showed a large tumor in the dorsolateral brainstem accompanied by hydrocephalus as well as a cervicothoracic syrinx extending to the level of T-8. She underwent endoscopic third ventriculostomy that resulted in a marked decrease in the ventricle size as well as complete resolution of the syrinx and tonsillar herniation within 4 days. Clinical and neuroimaging findings of the case along with a pertinent literature review are presented.

Acquired cervical syringomyelia secondary to a brainstem meningioma in a maltese dog

A 15-year-old female maltese was referred to us because of a 3-month history of ataxia, circling, and acute blindness. A mass was noted in the brainstem on brain magnetic resonance images. A cerebellar herniation was also detected on T1-weighted sagittal images. The lateral, third and fourth ventricles and central canal of the cervical spinal cord were enlarged. Based on diagnostic imaging findings, cervical syringomyelia secondary to a brainstem tumor was suspected. The clinical signs were controlled well by lomustine and the dog survived for 8 months after the initial diagnosis. The mass was diagnosed as a meningioma based on histopathological findings. This report describes the clinical findings and imaging characteristics of an acquired syringomyelia resulting from a brainstem meningioma.

Acute presentation of hydromyelia in a child

The authors document a rapid development, within 3 weeks, of hydromyelia in a 12 year-old boy. The boy was admitted to a local hospital because of drowsiness and persistent severe neck pain. Neurological examination disclosed a lethargic boy with no neurological deficit other than Parinaud's sign. During his transfer to our department, he presented a cardio-respiratory arrest with coma and bilateral mydriasis. External ventricular drain and craniocervical decompression achieved excellent clinical and neuroradiological outcomes. The development of hydromyelia in this case is caused by obstruction to the natural cerebrospinal fluid pathway at the craniocervical junction and the cardio-respiratory arrest is provoked by a brain stem compression against the clivus and odontoid process. This report illustrates that hydromyelia may complicate acute obstructive hydrocephalus due to acquired Chiari malformation.

Tonsillar herniation and cervical syringomyelia in association with posterior fossa tumors in children: a case-based update

BACKGROUND

Posterior fossa tumors most commonly occur in children. They frequently present with raised intracranial pressure and may have tonsillar herniation. The symptomatology is predominantly directed towards the tumor. The occurrence of syringomyelia in such cases is most unusual. Symptomatic syringomyelia is rare.

CASE REPORT

We describe a case of a pilocytic astrocytoma of the cerebellum in a 13-year-old girl who presented with clinical features of progressively worsening raised intracranial pressure and secondary tonsillar herniation and cervical syringomyelia. Magnetic resonance (MR) imaging showed a large midline inhomogenously enhancing vermian tumor causing moderate obstructive hydrocephalus. In addition, the cerebellar tonsils herniated down to the C2 level, and there was a centrally located syrinx from C2-T1. The tumor was resected through a suboccipital craniectomy. At follow-up after 3 months, MR imaging demonstrated total resolution of tonsillar herniation and cervical syringomyelia.

CONCLUSIONS

The occurrence of tonsillar herniation and syringomyelia in association with a slow growing benign tumor like pilocytic astrocytoma of the cerebellum is uncommon. The blockade of normal cerebrospinal fluid circulation pathway at the foramen magnum is the crucial factor. Surgical extirpation of the tumor restores the normal cerebrospinal fluid circulation at the foramen magnum and produces an excellent outcome. The need for an additional surgical procedure for treatment of associated tonsillar herniation and syringomyelia can be avoided. Volumetric assessment of the posterior fossa may provide a better understanding of the pathophysiology of syringomyelia in such patients.

Resolution of tonsillar herniation and cervical syringomyelia following resection of a large petrous meningioma: case report and review of literature

We describe a case of a large, petrous meningioma associated with tonsillar herniation and cervical syringomyelia. The patient, a 53-year-old woman, had a 6-month history of a dull, aching pain in the occipital region associated with numbness in the right C2 dermatome and left gaze evoked nystagmus. Magnetic resonance imaging (MRI) revealed a large tumor in the right posterior fossa associated with moderate supratentorial hydrocephalus. Secondary tonsillar herniation and cervical syringomyelia extending from C2 to C6 were also identified. The tumor, later confirmed to be a meningioma originating from the petrous region, was resected completely via a retrosigmoid approach. Postoperative MRI demonstrated total resolution of the tonsillar herniation and cervical syringomyelia. The radiological features, potential pathophysiological mechanisms, and treatment strategies are discussed in relation to the recent literature.

Asymptomatic syringomyelia in the course of medulloblastoma

Syringomyelia is frequently associated with Chiari malformation or one of many other pathological conditions. Its co-occurrence with medulloblastoma is rare, and to our knowledge, only 4 patients have been reported, although some reports have documented on syringomyelia associated with intracranial processes or intramedullary tumor. The authors describe an unusual case of asymptomatic thoracic syringomyelia complicated by an intrasyringal hemorrhage in a child with medulloblastoma. This report illustrates that, although unusual, syringomyelia is a potential complication in the natural history of medulloblastoma, and the authors consider the possible pathogenesis of syrinx enlargement.

Trigeminal neurinoma associated with Chiari malformation and syringomyelia

We report a 36 year-old woman who presented with headaches and hypoesthesia of the face. MRI revealed a large dumbbell shaped trigeminal neurinoma extending into both the middle and the posterior cranial fossae. In addition, there was a Chiari I malformation and syringomyelia. Within two months of tumor resection, both the Chiari malformation and the syringomyelia resolved. The association of an intracranial space-occupying lesion with Chiari malformation and syringomyelia is reviewed.

Cervical syringohydromyelia secondary to a brainstem tumor in a dog

An 11-year-old male Pekingese was evaluated because of a history of head tilt. Neurologic examination revealed a right-sided head tilt, ataxia, scoliosis, and proprioceptive deficits. Diagnostic testing included magnetic resonance imaging (MRI) of the head and neck. After IV administration of gadopentetate dimeglumine, an extra-axial, highly contrast-enhanced mass in the brainstem, cerebellar herniation, and syringohydromyelia were detected via MRI. The dog was treated with corticosteroids and radiation therapy of the mass for 4 weeks (total dose, 42.5 Gy). Magnetic resonance imaging was repeated 9 weeks and 6 months after radiation therapy; compared with the initial findings, a reduction in the size of the brainstem mass was observed in both MRI scans. The third MRI scan also revealed a normal cerebellar shape, no evidence of herniation, and resolution of syringohydromyelia in the dog at that time. It is recommended that whenever syringohydromyelia is observed via MRI, a primary cause (cranial or caudal to the affected region) should be sought.

Posterior fossa decompression for life-threatening tonsillar herniation in patients with gliomatosis cerebri: report of three cases

OBJECTIVE AND IMPORTANCE

Gliomatosis cerebri (GC) is a rare type of primary brain tumor that diffusely infiltrates more than two lobes of the brain while the normal cerebral architecture is maintained. To the best of our knowledge, the association between an acquired tonsillar herniation and GC has never been reported. In this article, we describe three patients with progressive gliomatosis of the cerebellar hemispheres who subsequently showed signs and symptoms secondary to tonsillar herniation. Early recognition of this potentially life-threatening complication allowed us to recommend prompt surgical intervention.

CLINICAL PRESENTATION

One patient with primary, or Type I, GC presented with suboccipital headaches, and two patients with secondary, or Type II, GC presented with the signs and symptoms of progressive myelopathy. Serial imaging studies demonstrated progressive involvement of the cerebellum, descent of the cerebellar tonsils through the foramen magnum, and cervicomedullary spinal cord compression.

INTERVENTION

Once the tonsillar herniation was recognized, all three patients underwent posterior fossa decompression, a cervical laminectomy to the lowest level of the tonsillar herniation, and duraplasty. All three patients experienced immediate improvement in their conditions.

CONCLUSION

Early recognition of tonsillar herniation, a possibly overlooked cause of death in patients with GC, allows for early surgical intervention as a potentially lifesaving procedure and significant improvement in the patient's condition.

A craniocervical injury-induced syringomyelia caused by central canal dilation secondary to acquired tonsillar herniation. Case report

The authors report on a 19-year-old man with an acquired tonsillar herniation caused by a craniocervical junction injury in which serial magnetic resonance (MR) images demonstrated patent and isolated segments of the central canal participating in the dilation and then formation of a cervical syrinx. The patient was involved in a motor vehicle accident; he developed tonsillar herniation as a complication of subarachnoid and epidural hemorrhage, predominantly observed around the cisterna magna and upper cervical canal. Repeated MR images obtained over an 11-month period indicated the for mation and acute enlargement of the syrinx. Ten months after the accident, the patient presented with sensory disturbance in both upper extremities and spasticity due to syringomyelia. He underwent craniocervical decompressive surgery and doraplasty, which reduced the size of syringomyelia. The authors postulate that the patent central canal may play a role in determining the location of a syrinx remote from a focus of cerebrospinal fluid obstruction.

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

OBJECTIVE AND IMPORTANCE

Indications for surgery and the surgical technique of foramen magnum decompression for patients with Chiari I malformation and syringomyelia are controversial issues. This case report supports the view that observation may be adequate for patients without progressive symptoms or with mild clinical symptoms.

CLINICAL PRESENTATION

A 37-year-old woman presented with a 3-month history of burning dysesthesias and hypesthesia in her right arm. A neurological examination revealed hypesthesia in the right trigeminal distribution. A magnetic resonance imaging scan revealed a Chiari I malformation with syringomyelia between C2 and T2. No hydrocephalus was observed.

CLINICAL COURSE

Because the patient's symptoms regressed spontaneously, surgery was not performed. Thirty-two months after her initial examination, the patient was asymptomatic. A second magnetic resonance imaging scan was obtained, which demonstrated complete spontaneous resolution of the Chiari I malformation and syringomyelia.

CONCLUSION

We attribute the regression of the patient's symptoms to spontaneous recanalization of cerebrospinal fluid pathways at the foramen magnum, which most likely was due to rupture of the arachnoid membranes that had obstructed cerebrospinal fluid flow.

Resolution of tonsillar herniation and syringomyelia after supratentorial tumor resection: case report and review of the literature

OBJECTIVE AND IMPORTANCE

The pathophysiological features of syringomyelia are not yet entirely understood. We present a case of a supratentorial mass causing tonsillar herniation and syringomyelia.

CLINICAL PRESENTATION

A 51-year-old woman underwent magnetic resonance imaging for evaluation of progressive headaches. A large parieto-occipital mass was revealed. Herniation of the cerebellar tonsils and a cervical syrinx were also noted.

INTERVENTION

A craniotomy was performed without incident. After tumor resection, the tonsils ascended and the syrinx resolved in a 1-year period.

CONCLUSION

This case highlights the importance of tonsillar herniation in the pathogenesis of syringomyelia. "Acquired" Chiari malformations and syringomyelia attributable to supratentorial masses may be treated by mass resection alone, without the need for foramen magnum decompression.

The “presyrinx” state: is there a reversible myelopathic condition that may precede syringomyelia?

Object

Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a “presyrinx” condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord.

Methods

Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow.

Results

Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction.

Conclusion

Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the “presyrinx” state and stress the importance of timely intervention to limit progression to syringomyelia.

Syringomyelia persistence after Chiari decompression as a result of pseudomeningocele formation: implications for syrinx pathogenesis: report of three cases

OBJECTIVE AND IMPORTANCE

We present the cases of three patients in whom pseudomeningocele (PSM) formations after posterior fossa decompression of hindbrain herniations (Chiari I malformations) were associated with persistence of syringomyelia. The physiological importance of correcting this complication has not been previously described.

CLINICAL PRESENTATION

We identified three patients who developed suboccipital PSMs after undergoing posterior fossa decompression for hindbrain herniations and syringomyelia. All three patients experienced persistence of their symptoms and their syringomyelia, despite adequate posterior fossa decompression.

TECHNIQUE

Subsequent exploration revealed cerebrospinal fluid leaking either from the dural suture line (one patient) or from perforations found within the bed of a polyglactin mesh dural graft (two patients). Correction of the PSM resulted in resolution of both the syringomyelia and the symptoms in all three patients.

DISCUSSION

The persistence of syringomyelia in the presence of a PSM may be the result of dissipation of the cerebrospinal fluid systolic pressure wave into the distensible PSM cavity. This phenomenon suggests that the cerebrospinal fluid pressure exerted on the spinal cord surface favors resolution of the syrinx cavity.