Spinal intramedullary ependymal cyst. Report of three cases

Three cases of spinal intramedullary ependymal cyst, two at the thoracolumbar junction and one in the cervical spinal cord, are reported in women in their fifth to seventh decades. Neurological signs and symptoms were extremity dysesthesias, paresthesias, and weakness. Plain cervical and lumbothoracic x-ray films were normal for the patients' age. Magnetic resonance (MR) imaging demonstrated a rounded cystic intramedullary mass at the thoracolumbar junction in two cases and at C3-7 in one case. The signal intensity of the cyst contents approximated that of cerebrospinal fluid on T1- and T2-weighted images. Upon administration of gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA), MR imaging showed no enhancement in the cyst wall or cavity. Myelotomy and cyst drainage were performed in each case, and the neurological status of each patient improved. The lining of the cyst was biopsied in one of the three patients undergoing surgery and was composed of a single layer of cuboidal cells supported by glial tissue. Periodic acid-Schiff staining of the tissue did not reveal a basement membrane. The findings in these cases suggest that the Gd-DTPA-enhanced MR imaging appearance of intramedullary spinal ependymal cyst is consistent and allows for accurate preoperative diagnosis with or without biopsy.     

Experimental syringohydromyelia induced by adhesive arachnoiditis in the rabbit: changes in the blood-spinal cord barrier, neuroinflammatory foci, and syrinx formation

There are many histological examinations of syringohydromyelia in the literature. However, there has been very little experimental work on blood permeability in the spinal cord vessels and ultrastructural changes. We prepared an animal model of spinal adhesive arachnoiditis by injecting kaolin into the subarachnoid space at the eighth thoracic vertebra of rabbits. The animals were evaluated 4 months later. Of the 30 rabbits given kaolin injection into the cerebrospinal fluid, 23 showed complete circumferential obstruction. In the 7 animals with partial obstruction of the subarachnoid space, intramedullary changes were not observed. However, among the 23 animals showing complete obstruction of the subarachnoid space, dilatation of the central canal (hydromyelia) occurred in 21, and intramedullary syrinx (syringomyelia) was observed in 11. In animals with complete obstruction, fluorescence microscopy revealed intramedullary edema around the central canal, extending to the posterior columns. Electron microscopy of hydromyelia revealed a marked reduction of villi on the ependymal cells, separation of the ependymal cells, and cavitation of the subependymal layer. The dilated perivascular spaces indicate alterations of fluid exchange between the subarachnoid and extracellular spaces. Syringomyelia revealed that nerve fibers and nerve cells were exposed on the surface of the syrinx, and necrotic tissue was removed by macrophages to leave a syrinx. Both pathologies differ in their mechanism of development: hydromyelia is attributed to disturbed reflux of cerebrospinal fluid, while tissue necrosis due to disturbed intramedullary blood flow is considered to be involved in formation of the syrinx in syringomyelia.     

Intramedullary spinal ependymal cyst: case report

A cervical intramedullary spinal ependymal cyst in a 39-year-old man is reported. Diagnosis was made through magnetic resonance imaging. Total enucleation was possible. This is the sixth such reported case.     

Diagnostic and Therapeutic Management of Spinal Arachnoid Cysts

Summary Background. The wide variety of intraspinal cystic lesions necessitates different elaborate diagnostic procedures to choose the right therapeutic management in symptomatic patients. Based on the case reports of seven patients with symptomatic spinal arachnoid cysts we discuss the aetiology, diagnostic procedures and therapeutic management of extra- and intradural spinal cysts.  Method. All patients underwent MRI, Myelography and CT-Myelography during diagnostic evaluation. During surgery the cyst was resected and the communication between the cyst and the subarachnoid space was closed.  Findings. Two patients were identified with intradural, five with extradural spinal arachnoid cysts. Postoperative outcome was favourable in those patients without preoperative cord damage.  Interpretation. MRI is the diagnostic procedure of first choice because of its potential to demonstrate the exact localisation, extent and relationship of the arachnoid cyst to the spinal cord. Cord atrophy secondary to compression can be visualised and used for prediction of neurological outcome. Myelography and CT-Myelography (CTM) are still of diagnostic value since they might demonstrate the communication between the subarachnoid space and the cyst, which is important for surgical planning. The aim of surgical treatment is neural decompression and prevention of refilling of the cyst which is best accomplished by complete resection of the cyst and closure of the communication between cyst and subarachnoid space.     

Intramedullary epithelial cyst of the spinal cord

A female patient with an intramedullary cyst presented with a paraplegia. At operation an intramedullary cyst at the fourth dorsal level was found. The microscopic features of the cyst wall were suggestive of ependymal origin.     

Non-communicating extradural arachnoid cyst of dorsal spine

Extradural arachnoid cyst in the spine is an uncommon cause of spinal cord compression in the paediatric population. Most reported cysts have communication with the intrathecal subarachnoid space through a small defect in the dura. The reported child had spinal cord compression caused by a large spinal extradural arachnoid cyst in dorsal spine that did not communicate with the intradural subarachnoid space. Surgical excision of cyst was done with recovery of neurological deficit postoperatively.     

Sacral meningeal cyst associated with valve-like mechanism--case report

A 58-year-old woman presented with low back pain radiating to the lower extremities. Magnetic resonance imaging revealed a cystic lesion in the sacrum compressing the nerve roots. At operation, a valve-like communication was found between the subarachnoid space and the cyst cavity in the vicinity of the sacral nerve root. The communication was obliterated with a purse-string suture and reinforced with a free muscle graft. Postoperatively, she reported improvement of the pain. Valve-like communication between the cyst cavity and subarachnoid space can cause enlargement of spinal meningeal cyst, and could also explain enlargement of sacral meningeal cyst. Surgical obliteration of the communication rather than the cyst resection is more important for sacral meningeal cyst.     

A case of intramedullary spinal cavitation after minor trauma

A case of surgically treated intramedullary spinal cavity which appeared 1 year after a minor injury was presented. A 15 year-old boy developed nuchalgia and muscle weakness of his right arm and leg. On admission, he had right hemiparesis and sensory disturbances in the right C6-C8 and left T1-S5 dermatomes. Metrizamide-CT scan and MRI disclosed an intramedullary spinal cavity between C4-C5 vertebral levels. A myelotomy and a biopsy of the cavity wall were carried out in order to communicate the cavity with the subarachnoid space, and to make a definite diagnosis. The microscopic examination of a biopsy specimen revealed no tumor findings but inflammation. Taking into account the location of the cavity, a site corresponding with the site of a previous trauma, the authors finally diagnosed the cavity as intramedullary spinal cavitation after minor trauma. His symptoms improved remarkably after the operation.     

Spinal intramedullary ependymal cyst: a case report and review of the literature

Summary We report a rare case of spinal intramedullary ependymal cyst in a 44-year-old female and reviewed 12 cases reported in the literature. The patient presented with slowly progressive lower limb paresis. She underwent biopsy of the cyst wall and placement of a cysto-subarachnoid shunt with complete recovery at the follow-up examination 18 months after surgery. This is a benign lesion and appropriate management should be performed at an early stage of the disease.     

Non-hindbrain-related syringomyelia. Obstruction of the subarachnoid space and the central canal in rats. An experimental study

BACKGROUND: The aim is to determine the mechanism of non-hindbrain-related syringomyelia in experimental models. The effects of obstruction of central canal and subarachnoid space on occurrence of cavities were discussed. METHODS: 31 Sprague-Dawley rats were used with eight (Group D) as a control. In 10 rats (Group A) 1.5 microl kaolin was microinjected into the dorsal columns and central gray matter of the spinal cord at the level of Th6-10. In 10 rats (Group B) 0.1 cc kaolin was injected into the subarachnoid space at the same level. In 3 rats (Group C), 1.5 microl kaolin was administered into both dorsal midline of the spinal cord and the subarachnoid space. RESULTS: In Group A, histological examination revealed cystic cavity and dilatation of the central canal in five rats; denuded ependymal line and multicystic formations in ependymal and periependymal areas in seven rats. In Group B, denuded ependymal line in three rats and microcystic formations in ependymal and periependymal areas in four rats were revealed. In Group C, there were microcystic formations in two rats and syrinx cavity in one rat. CONCLUSIONS: Developments leading to occurrence of cavities are focused on the central canal in all groups. These models indicate that the CSF-flow is from the subarachnoid space to the central canal leading to changes of cavities. In cases of obstruction of the subarachnoid space or the central canal, the occurrence of syrinx cavity initially is due to increased CSF (cerebrospinal fluid) pressure in the central canal. Flow changes in spinal cord is indicated by this study.     

Intradural extramedullary cysts of the spinal canal: clinical presentation, radiographic diagnosis, and surgical management.

Fourteen patients with intradural extramedullary cysts of the spinal canal are described. Histological classification included 11 arachnoid, 2 epithelial, and 1 ependymal cyst. There were 9 thoracic, 3 cervical, and 2 lumbar cysts. The most common clinical presentation was a slowly progressive myelopathy. Twelve patients (85%) had objective neurological findings at the time of diagnosis. Radiographic diagnosis was made by a combination of myelography, computed tomographic scan with myelography, and magnetic resonance imaging. Complete surgical resection was accomplished for 8 dorsal cysts, and 6 ventral cysts were widely fenestrated into the subarachnoid space. Overall results were considered excellent or good in 9 patients, fair in 3, and poor in 2. There was one recurrence, which required a second operation. We conclude that the majority of intradural spinal cysts can be successfully managed surgically with a favorable clinical outcome.     

Isolated intramedullary spinal cord cysticercosis

We report a case of intradural, intramedullary, spinal cord neurocysticercosis at dorsal 10-11 (D10-11) level in a mentally retarded male. A 38-year-old, mentally retarded male presented with weakness and stiffness in both the lower limbs and waist since one year. Magnetic resonance imaging revealed a D10-D11 intradural space occupying lesion with cord compression. Intraoperatively, the tumor was grayish white, soft, cystic, and intramedullary with a well-defined plane with surrounding cord tissue. Gross examination revealed a cystic lesion of 1.5×1×0.8 cm, with a whitish nodule of 0.3 cm in diameter. The cyst wall was thin, shiny, and translucent. Microscopic examination revealed cysticercous cyst. Spinal neurocysticercosis should be considered in differential diagnosis of spinal mass lesion in patients residing in endemic area such as India.     

Intramedullary neurenteric cyst without any associated malformation one case evaluated by RMI and electron microscopic study

Summary A 46 years old woman presented with several years history of low back pain. For five years she suffered from weakness of the left lower limb and three years later she experienced an episode of righ foot weakness. She suffered too from occasionnal urinary urgency. The examination showed decreased power and diminished sensory perception in the left leg. On myelography, a block at L2 level was observed. RMI evaluation showed an intramedullary cyst in the anterior part of the spinal cord without any enhancement of its wall by the Gadolinium. At operation a thin-wall cyst was found containing clear fluid. After a biopsy of the wall, a cystosubarachnoid shunt was performed. Histological examination of the surgical sample showed a simple cuboidal epithelium lying on collagen fibrills. Electron microscopic studies showed ciliated cells with a clearly-visible basement membrane. The diagnosis of neurenteric cyst was confirmed. In the postoperative course the patient complained about sensory loss of the legs and the perineal area. Six months later, she exhibited a sensory disturbance of the feet and the right sacral area, a motor deficit of the distal left leg without urinary disturbance. Neurenteric cysts are dysraphic lesions which can be observed without other abnormalities. They are usually extra-medullary and the intramedullary forms are very rare: among 5 cases reported in the literature, one has been evaluated by RMI. In the absence of enhancement by the Gadolinium, the other possible diagnosis seems an ependymal cyst. Contrary to extramedullary forms the postoperative course of intramedullary neurenteric cysts are not always eventfull. Because the cyst wall cannot be removed, repeated RMI are desirable in the follow-up.     

Updated assessment and current classification of spinal meningeal cysts

The classification of spinal meningeal cysts (MC's) in the literature is indistinct, confusing, and in certain categories histologically misleading. Based on a series of 22 cases, the authors propose a classification comprising three categories: spinal extradural MC's without spinal nerve root fibers (Type I); spinal extradural MC's with spinal nerve root fibers (Type II); and spinal intradural MC's (Type III). Although water-soluble myelography may disclose a filling defect for all three categories, computerized tomographic myelography (CTM) is essential to reveal communication between the cyst and the subarachnoid space. Communication demonstrated by CTM allows accurate diagnosis of a spinal MC and rules out other mass lesions. Magnetic resonance imaging appears useful as an initial study to identify an intraspinal cystic mass. Final characterization is based on operative inspection and histological examination for all three categories.     

Dermoid cyst: A rare intramedullary inclusion cyst

Intramedullary dermoid cysts are rare tumors, especially those not associated with spinal dysraphism. Only six cases have been reported in the literature. Of these, only two cases have had magnetic resonance imaging studies. We report a case of an 18-year-old female patient, who presented with progressive weakness of both the lower limbs and wasting of both the upper limbs. Magnetic resonance imaging (MRI) showed an intramedullary lesion extending from C3 to D2 with peripheral enhancement on contrast. Decompression of the cystic contents with partial removal of cyst wall was done. Hair with oily cholesterol and keratin debris was encountered. Histopathology confirmed the diagnosis of dermoid cyst. This case adds to the previous reported cases of the rare and uncommon intramedullary space occupying lesions of the spinal cord.     

Excitotoxic model of post-traumatic syringomyelia in the rat

STUDY DESIGN: A rat model was developed to elucidate the role of excitatory amino acids and spinal subarachnoid block in the genesis of post-traumatic syringomyelia. This excitotoxic model produces intramedullary cavities rather than the dilation of the central canal (canalicular syringomyelia) created by previous animal models. OBJECTIVES: To produce extracanalicular cysts in the rat spinal cord with quisqualic acid, a potent agonist of multiple excitatory amino acid receptors, and to compare the effects of excitotoxic injury only with that of excitotoxic injury and subarachnoid block with kaolin. SUMMARY OF BACKGROUND DATA: In post-traumatic syringomyelia, primary injury and excitotoxic cell death secondary to elevated levels of excitatory amino acids may initiate a pathologic process leading to the formation of spinal cavities. Subarachnoid block by arachnoiditis may promote enlargement of the cavities. METHODS: Three control rats received a unilateral injection of normal saline into the spinal cord, and another five rats received an injection of kaolin into the spinal subarachnoid space. Quisqualic acid was injected unilaterally into the spinal cord of 20 rats, and 13 additional rats received a unilateral injection of quisqualic acid into the spinal cord after injection of kaolin into the subarachnoid space. Histologic and immunocytochemical assessments were undertaken. RESULTS: In the control groups, no parenchymal cyst developed in any of the animals. Spinal cord cyst formation was observed in 16 of 19 animals in the quisqualic acid groups, but no cysts exceeding two segments in the length of the spinal cord developed in any of the rats. Much larger cavities were seen in 9 of 11 animals in the group with quisqualic acid and kaolin, and cysts exceeding two segments developed in all 9 of these (9/11; 82%). CONCLUSIONS: In post-traumatic syringomyelia, excitotoxic cell death occurring secondarily to elevated levels of excitatory amino acids may contribute to the pathologic process leading to the formation of spinal cord cysts. Subarachnoid block by arachnoiditis is likely to cause enlargement of the cavity.     

Spinal intramedullary ependymal cyst and tethered cord in an adult. Case report

Spinal intramedullary ependymal cysts are extremely rare. Fourteen cases have been reported in the literature, and only one was associated with another congenital lesion. The authors describe the case of a 33-year-old man in whom an intramedullary ependymal cyst and filar lipoma were present. These lesions were diagnosed using magnetic resonance imaging and were treated surgically. Pathological examination confirmed the diagnosis. At 6 months postsurgery, there was no evidence of recurrence.     

Sacral nerve root cysts manifesting as localized unilateral perineal pain--case report.

A 62-year-old female presented with multiple sacral nerve root cysts manifesting as localized unilateral perineal pain. Myelography just after contrast material injection revealed multiple cysts at the sacral level. However, perioperative dye injection showed hardly any flow in the reverse direction. Only the S3 nerve was constricted by hyperplasia of the dura mater, and adhered to the cyst wall. Other nerves were not constricted, nor adhered to cyst walls. The S3 nerve constriction and tight adhesion was the cause of the pain. The one-way flow of spinal fluid from the spinal subarachnoid space to the cysts is probably closely correlated with cyst formation.     

Clinical characteristics and surgical outcomes of spinal intramedullary ependymal cysts

Object

Intramedullary ependymal cysts are exceedingly rare lesions, and have been previously reported in the literature as case reports. The aim of this study was to discuss the clinical presentation and the outcomes of microsurgery for these benign lesions.

Methods

The authors retrospectively reviewed the records of ten patients who underwent microsurgery for intramedullary ependymal cysts. All patients had preoperative and postoperative magnetic resonance imaging. The surgical treatment included gross total resection and biopsy plus a cyst-subarachnoid shunt. The diagnosis of intramedullary ependymal cysts was based on radiological and pathological criteria. All patients were followed up, with a mean duration of 47.6 months.

Results

Intramedullary ependymal cysts were hypointense on T1-weighted images and hyperintense on T2-weighted images. Contrast-enhanced T1-weighted images showed no enhancement. Gross total resection was achieved in one case. Biopsy of the cyst wall plus cyst-subarachnoid shunt placement was achieved in nine cases. Long-term neurological function was improved in eight patients. No recurrence was observed on magnetic resonance imaging.

Conclusions

Ependymal cysts should be considered in the differential diagnosis of intramedullary cysts. For symptomatic patients, early surgery should be performed before neurological deficits deteriorate. Complete decompression and cyst-subarachnoid shunt placement is the optimal treatment and the outcome may be favorable.