Spinal arachnoid diverticula

Cine MRI Is Useful for the Diagnosis of Intradural Arachnoid Cyst with Spinal Arachnoid Web: A Case Report

CASE

A 28-year-old woman developed gait disturbance due to lower limb weakness 3 years before presentation. Conventional magnetic resonance imaging (MRI) findings were inconclusive; therefore, we performed cine MRI, which confirmed the presence of a pulsatile cyst on the posterior thoracic spinal cord. The cyst compressed the spinal cord, and its pulsations synchronized with the patient's heartbeats. We resected the intradural arachnoid cyst and thickened arachnoid membrane. The gait disturbance improved after surgery.

CONCLUSIONS

Cine MRI can be used to identify a pulsating arachnoid cyst that cannot be visualized with a conventional MRI. Cine MRI is useful in patients with unexplained spinal symptoms.

Neuroimaging findings and pathophysiology of dorsal spinal arachnoid webs: illustrative case

BACKGROUND

Spinal arachnoid webs are uncommon and difficult to diagnose, especially because causative intradural transverse bands of arachnoid tissue are radiographically occult. Left untreated, arachnoid webs may cause progressive, debilitating, and permanent neurological dysfunction. Conversely, more than 90% of patients may experience rapid neurological recovery after resection, even with a prolonged duration of presenting symptoms. Indirect imaging signs such as spinal cord indentation and compression with cerebrospinal fluid (CSF) flow alteration provide crucial diagnostic clues that are critical in guiding appropriate management of such patients.

OBSERVATIONS

The authors reported a patient with no significant medical history who presented with back pain, progressive lower extremity weakness, gait ataxia, and bowel and bladder incontinence. They discussed multimodality imaging for determining the presence of arachnoid webs, including magnetic resonance imaging, phase-contrast CSF flow study, computed tomography myelography, and intraoperative ultrasound. They also discussed the detailed anatomy of the spinal subarachnoid space and a plausible pathophysiological mechanism for dorsal arachnoid webs.

LESSONS

The authors report on a patient who underwent comprehensive imaging evaluation detailing the arachnoid web and whose subsequent anatomical localization and surgical treatment resulted in a full neurological recovery.

Symptomatic Thoracic Nerve Root Herniation into an Extradural Arachnoid Cyst: Case Report and Review of the Literature

BACKGROUND

Spinal extradural arachnoid cysts (SEACs) are relatively rare and usually asymptomatic. They preferentially are situated in the thoracic extradural space and almost always dorsal. SEACs may present with back pain and/or cord compression symptoms. Needle aspiration, needle fenestration, or open surgical resection/fenestration have been reported as treatment modalities.

CASE DESCRIPTION

We present a 35-year-old woman who complained of radiating pain from the right lower thoracic region of her back toward the right inguinal region, which was aggravated upon defecation and straining. Magnetic resonance imaging (MRI) revealed an extradural cyst located laterally at T11-T12 level on the right, with a nerve root herniation. During a T11-T12 hemilaminectomy, on resection of the cyst wall, a nerve root was noted to be herniating into the cyst cavity through a dural defect. The nerve root was released and repositioned intradurally, followed by direct suture of the dural tear. Histologic findings of the cyst wall confirmed an arachnoid cyst. Postoperative course was uneventful without complications. Postoperative MRI confirmed a complete resection of the cyst. Five years after surgery, the patient is asymptomatic with complete recovery.

CONCLUSIONS

Thoracic SEACs can present with radiating pain due to a transdural herniation of a thoracic nerve root into the cyst, potentially due to a mechanism of intermittent pressure gradients between the intradural and extradural spaces. MRI can prove beneficial in visualizing the nerve prolapsing into the cyst. Open resection of the cyst wall, reduction of the nerve root herniation, and subsequent direct closure of the dural tear led to complete recovery.

Idiopathic intradural dorsal thoracic arachnoid cysts: A case series and review of the literature

BACKGROUND

Spinal intradural arachnoid cysts (SIAC) are cerebrospinal fluid (CSF) filled sacs formed by arachnoid membranes and may be either idiopathic or acquired. Idiopathic cysts represent a separate entity and their aetiology remains uncertain. By far the most difficult differential diagnosis is distinguishing between idiopathic anterior spinal cord herniation (IASCH) and dorsal thoracic intradural arachnoid cysts (TIAC), due to their similarity in radiological appearance. Cine-mode (SSFP) is emerging as a novel technique in the diagnosis and operative planning of SIAC.

METHOD

Retrospective analysis of patients with idiopathic TIACs that were surgically managed at Royal North Shore Hospital and North Shore Private Hospital between November 2000 and November 2015.

RESULTS

Ten patients were included in this study. Age ranged from 20 to 77years with a mean age of 60years and a female preponderance. The most common clinical features were progressive gait ataxia and lower limb myelopathy. Radicular pain tends to improve following surgery, however gait ataxia may not.

DISCUSSION

While there are circumstances in which the distinction between dorsal thoracic intradural arachnoid cysts and idiopathic anterior spinal cord herniation are radiologically obvious, in cases where the appearances are less clear, cine-mode SSFP MRI imaging can provide an invaluable tool to differentiate these pathologies and lead the clinician towards the correct diagnosis and management. The mainstay of surgical management for dorsal TIACs is laminectomy and cyst excision or fenestration. Surgery for gait ataxia should be aimed towards preventing deterioration, while maintaining the potential for symptomatic improvement, whereas surgery for radicular pain should be curative.

Thoracolumbar extradural arachnoid cysts: a study of 14 consecutive cases

BACKGROUND

To investigate characteristic clinical and radiological features of extradural arachnoid cysts (EDACs) in the thoracolumbar region, a retrospective review of medical records and imaging studies was performed. EDACs are well known but relatively rare lesions in the thoracolumbar spinal canal. The most common site is the lower thoracic spine, and it may cause neurological symptoms by compressing the spinal cord or nerve root. In this study, the pathogenesis, symptomatology, diagnostic approach, and surgical management of EDACs will be discussed.

METHODS

We studied 14 consecutive patients who were surgically treated for EDACs in the thoracolumbar region at our institute between March 2000 and January 2011. The history, clinical presentations, image findings, operative findings, and surgical outcomes of these patients were retrospectively analyzed. The mean follow-up period was 28 months (range: 6-72 months).

RESULTS

Progressive motor weakness was the predominant symptom in all patients. Nine patients had radicular leg pain and back pain in the thoracolumbar area. On MRI, the cyst compressed the dural sac and spinal cord posteriorly typically with bilateral foraminal extensions. On radiological study, a communication point with the subarachnoid was hardly observed. The surgical treatment of EDACs included complete resection of the walls and closing the communicating point with the subarachnoid space. All patients showed excellent outcomes according to Odom's criteria without recurrence. One CSF leakage and one postoperative hematoma were noted.

CONCLUSIONS

Thoracolumbar EDAC patients presented paraparesis and leg pain. Complete excision and closing the communicating point with the subarachnoid space were the choices of treatment, and the outcomes were favorable.

Recurrent spinal arachnoid cyst in a cat

Spinal arachnoid cysts (SACs) are uncommon expanding lesions in the spinal canal. They are rarely diagnosed in dogs, and there are only four published cases in cats. We report a case of a 12-year-old cat with recurrent signs of intermittent urinary incontinence and hind limb ataxia 2 years after surgical marsupialisation of a spinal arachnoid cyst at T11/12. Recurrence of a cyst was diagnosed by myelography. Repeated marsupialisation after laminectomy was successful and the cat recovered satisfactorily although intensive physical therapy was necessary. SACs are very rare in cats and seem to occur mainly as a secondary lesion to spinal and meningeal trauma or irritation due to bony changes of the vertebrae.

Compression médullaire par kystes arachnoïdiens

Spinal arachnoid cysts are considered to be rare entities, intradural locations are even less common. We report two cases of patients (two women aged 77- and 21-year-old) who presented spinal cord compression by intradural arachnoid cysts. For the second patient, repeated surgical procedures were necessary to improve the neurological status. After presenting the case reports, we expose the pathophysiological mechanisms and clinical features, and the surgical difficulties of treating this rare cause of spinal cord compression.

Rapid expansion of a ventral arachnoid cyst after syringo-subarachnoid shunting in the thoracic spinal cord: case report

BACKGROUND

Intradural spinal arachnoid cysts have rarely been reported in association with intramedullary cysts. These associated lesions most commonly occur in the thoracic spine.

CASE DESCRIPTION

We reported an unusual balance of cerebrospinal fluid dynamics between an initially occult arachnoid cyst and syringomyelia. The arachnoid cyst was not allowed to express itself until the syrinx was decompressed with a syringo-subarachnoid shunt.

CONCLUSION

Only one other report in the literature described a similar case; however, our case is the first to be confirmed by intraoperative ultrasound.

Spinal intradural juxtamedullary cysts in the adult: surgical management and outcome

OBJECTIVE

Intradural nonneoplastic cysts compressing the spinal cord are rare lesions. We retrospectively analyzed a series of patients harboring this entity with regard to clinical and radiological features, surgical management, and follow-up results.

METHODS

In a retrospective study, we reviewed the medical charts, radiological investigations, and follow-up data of 11 women and 10 men (mean age, 43.6 yr) with intradural juxtamedullary spinal cysts, which were consecutively treated microsurgically at our institutions between January 1995 and January 2003. All lesions were approached via a laminectomy, hemilaminectomy, or laminoplasty at the corresponding vertebral levels and histopathologically verified. The patients were routinely scheduled for clinical follow-up 2 and 6 months after surgery. Baseline postoperative magnetic resonance imaging (MRI) was ordered 6 months after surgery. Thereafter, follow-up was performed at 1-year intervals, with neurological examination and MRI.

RESULTS

According to presenting symptomatology, two main patient groups could be differentiated: one group with a myelopathic syndrome (10 patients) and another group with a predominant radicular pain syndrome (8 patients). Histopathological examination revealed 16 arachnoid cysts, 4 neuroepithelial cysts, and 1 cervical nerve root cyst. Most arachnoid cysts (12 cases) were located on the dorsal aspect of the thoracic spinal cord. The mean craniocaudal extension of these cysts was 3.7 vertebral levels, and complete resection was performed. In four patients, the arachnoid cyst was situated ventral to the spinal cord and involved up to 17 vertebral levels. These patients had a history of major spinal trauma, and the cyst was generously fenestrated at its greatest circumference as depicted on preoperative MRI scans. The four neuroepithelial cysts and the cervical nerve root cyst were located on the ventral or ventrolateral aspect of the spinal cord, and their maximum sagittal extension was two spinal vertebral levels. Symptoms in all but two patients demonstrated major improvement; in particular, radiating pain disappeared immediately after surgery. There was no cyst recurrence on MRI after a mean follow-up period of 3.2 years.

CONCLUSION

Intradural cysts should be considered in the differential diagnosis of lesions causing myelopathy and/or a radicular pain syndrome. Microsurgical resection or generous fenestration in cysts with large craniocaudal extensions effectively ameliorated patients' symptomatology. A description of the first documented case of a surgically treated intradural cervical nerve root cyst is provided.

Spinal Arachnoid Cyst Containing Nevus Cells in a Patient with a Large Congenital Melanocytic Nevus: Case Report

OBJECTIVE AND IMPORTANCE:

Spinal arachnoid cysts are rare, and their cause and pathogenesis remain controversial. We experienced a rare case with a large congenital melanocytic nevus in which a spinal arachnoid cyst contained nevus cells, suggesting the congenital nature of a spinal arachnoid cyst.

CLINICAL PRESENTATION:

A 37-year-old Japanese man had been born with a large melanocytic nevus on his back. He experienced intermittent pain radiating to both thighs and to the lower back and waist. A magnetic resonance imaging study disclosed the presence of a posterior intradural extramedullary arachnoid cyst extending from T10 through T12. His spinal cord was displaced anteriorly and flattened.

INTERVENTION:

An osteoplastic laminoplasty was performed, and the arachnoid cyst was totally removed. The cyst membrane exhibited many foci of brown deposits, and histological examination disclosed the presence of melanin-containing cells in the cyst membrane. Morphologically and immunohistochemically, the melanin-containing cells in the cyst membrane were similar to nevus cells in the dermis.

CONCLUSION:

The histological findings of our case suggest that the patient's spinal arachnoid cyst was formed at the same stage of development as the melanocytic nevus.

Thoracic Intradural Arachnoid Cyst Associated With Surgical Removal of Epidural Hematoma-Case Report-

A 54-year-old woman presented with a very rare association of spinal intradural arachnoid cyst and spinal epidural hematoma manifesting as paraparesis subsequent to severe back pain. Magnetic resonance (MR) imaging disclosed a ventral epidural hematoma extending from the T-4 to T-6 levels and compressing the spinal cord ventrally. Emergent surgical evacuation of the epidural hematoma was carried out 22 hours after the onset. MR imaging obtained 2 days after surgery showed enlargement of the dorsal subarachnoid space at the T-3 to T-8 levels. The patient could walk independently within 6 months after discharge, but paraparesis recurred 3 years after surgery. MR imaging showed formation of an intradural arachnoid cyst, which compressed the spinal cord dorsally. She underwent arachnoid cystectomy, and recovered ambulation postoperatively. This case of intradural arachnoid cyst of the thoracic spine which appeared after surgical removal of an epidural hematoma at the same spinal level indicates some association between the epidural hematoma and the arachnoid cyst.

An unusual spinal intradural arachnoid cyst

Spinal intradural arachnoid cysts are seen most frequently in the thoracic region, particularly near the midline posteriorly. A thoracic intradural arachnoid cyst in this typical location is reported, with the additional unusual finding of herniation of the spinal cord through an anterior defect in the dura matter. The MRI findings are described.

Craniospinal intradural arachnoid cyst

A patient with an uncommonly situated congenital intradural arachnoid cyst is reported. The cyst extended from the cervical spinal canal into the posterior cranial fossa and was posterolateral to the spinal cord. The patient's initial complaint was urinary hesitancy. The location of the cyst is unique and the presenting complaint rare.

A variant of the syndrome of spinal arachnoid cysts with multiple congenital defects

We report an apparently unique case of multiple spinal intradural arachnoid cysts in association with distichiasis, late onset lower limb lymphoedema, and previously unrecognized features of associated bilateral megaureters, Arnold Chiari malformation with hydrocephalus and syringomyelia. The literature on this unusual group of congenital malformations is reviewed.

Spinal arachnoid diverticula (report of a case and review of the literature)

We report a case of multiple spinal arachnoid diverticula in a four year old girl in order to draw attention to this entity as an unusual cause of spinal cord compression. The radiological findings and previous literature are reviewed.

Spinal meningeal malformations in children (without meningoceles or meningomyeloceles)

Multiple meningeal malformations are described: anterior or lateral meningoceles, extradural meningeal cysts, and intradural arachnoid cysts. All diverticulae appear to be extensions of the subarachnoid space, producing symptoms early or later. It is impossible to unify all these lesions because they cause multiple pathological conditions, depending upon the anatomical form or level, other systemic malformations, spinal abnormalities, or associated familial diseases. Surgical treatment requires complete evaluation of each anatomical aspect before procedure.

Intradural arachnoid cysts of the spinal canal associated with intramedullary cysts

Five patients had intradural arachnoid cysts of the thoracic spinal canal associated with syringomyelia or posttraumatic intramedullary spinal cord cysts. Three cases were diagnosed 6 to 18 years after spinal surgery and two 14 to 17 years after spinal cord trauma. In each case, delayed progression of symptoms led to the identification of the lesions. The diagnosis was assisted by the use of myelography and delayed computerized tomography scanning in two cases and by magnetic resonance imaging in all five. In each case, the arachnoid cyst appeared to compress the spinal cord or nerve roots; in three cases, the syrinx cavities appeared to exert a significant mass effect. In the two trauma-related cases, the intramedullary cysts were small and may have represented areas of cystic myelomalacia. In four cases, intraoperative real-time ultrasonography helped to localize the arachnoid and intramedullary cavities. All five patients were treated by fenestration of the arachnoid cyst; additional peritoneal shunting of the cyst was performed in one case and of the intramedullary cavity in three. In one patient, the two lesions appeared to have a balancing effect; after drainage of the arachnoid cyst, the syrinx cavity expanded and had to be treated separately. The neurological deficits were reduced in four patients and stabilized in one. Intradural arachnoid cysts and intramedullary cysts may occur together as a late complication of spinal surgery or spinal cord trauma, and either or both lesions may cause delayed neurological deterioration.

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.

Brainstem subarachnoid respiratory epithelial cysts: report of two cases and review of the literature

Two cystic lesions that were lined by pseudostratified ciliated columnar epithelium containing goblet cells are described. Both lesions were found in the subarachnoid space between the vertebrobasilar arterial system and the brainstem. One cyst was an incidental finding in a patient who died of orbital phycomycosis. The cyst was filled with clear mucinous material. The second cyst presented as a mass adjacent to the brainstem in a woman who had progressive brainstem dysfunction. This lesion showed transition from pseudostratified ciliated columnar epithelium with goblet cells to papillary stratified squamous epithelium, histologic features essentially identical to those of squamous papillomas of the nasal cavity. This lesion was filled with squamous debris. The proposed origin of these lesions is discussed.

Spinal arachnoid cyst with unusual presentation. Case report

A case is reported of spastic paraparesis due to a thoracic spinal arachnoid cyst. Symptoms occurred about 10 years after craniospinal injury. The histological examination revealed hemosiderin-containing macrophages trapped in the cyst wall. This finding and its possible pathogenetic implications are discussed, and the pertinent literature is reviewed.

Intraspinal arachnoid cysts

Arachnoid cysts are rare lesions responsible for spinal cord compression. Five cases of congenital intraspinal arachnoid cysts are reported. Three cases of thoracic and two cases of thoracolumbar region were encountered. The clinical presentation was one of progressive spastic paraparesis. The characteristic radiological features are described. Surgery was successful in all cases.

Intradural spinal cysts

18 cases of benign intradural spinal cyst (9 arachnoidal, 2 neuroepithelial, 7 endodermal) are reported and compared with 94 cases (67 arachnoidal, 7 neuroepithelial, 20 endodermal) obtained from the literature. Arachnoidal intradural cysts (AIC) have no sex preference, occur at around the fourth-fifth decades of life and have characteristic intermittent root symptoms. They prefer the thoracic level and the posterior position. (Myelography images the cystic cavity (diverticular form). Surgical removal is usually easy. Neuroepithelial intradural cysts (NIC) are rare, have a 2:1 predilection for females and occur after the fourth decade. They have a serious clinical course similar to intramedullary or extramedullary tumours. They prefer the conus-cauda and the anterolateral positions. They often give rise to manometric block and to albuminocytological dissociation. There may be substantial adhesions to the cord and roots and the intramedullary variety presents no clear plane of cleavage. Endodermal intradural cysts (EIC) have a 2:1 predilection for males and prefer the second and third decades. They may have an intermittent or serious course with signs of root and cord impairment. They prefer the cervical segment (in the anterior position) and the conus-cauda (in the posterior position). As a rule they present manometric block and albuminocytological dissociation. Their frequent tough adhesions to the roots and cord demand special care during their removal.

Intraspinal arachnoid cysts

Eight cases of intraspinal arachnoid cysts are described. The clinical, radiological, intraoperative and histological findings are presented and compared with similar reports in the literature. Opinions in the literature concerning the origin of arachnoid cysts are discussed, and compared with our own case reports. A traumatic or inflammatory origin of the arachnoid cysts is denied if accompanying histological changes are lacking. In such cases the arachnoid cysts are to be viewed as congenital malformations.

Spinal intradural arachnoid cyst

A case of spinal intradural arachnoid cyst is presented, and the literature dealing with this rare lesion is surveyed. The etiological and pathological features are discussed; emphasis is placed on the importance of correct interpretation of clinical and radiological findings that may be diagnostically misleading.

Spinal arachnoid cysts: clinical and radiological correlation with prognosis

The clinical and radiological findings in six extradural and nine intradural arachnoid cysts are discussed in relation to previous reports. Only two cysts failed to opacify during positive contrast myelography; in both cases Myodil was used and in one of them contrast medium had entered the cyst on delayed films taken at 24 h. Pain was always improved and generally cured by operation, only two patients having some residual backache. There was permanent improvement of neurological function in only eight cases. The factors associated with poor permanent recovery after surgical treatment were: 1) very marked thinning of the spinal cord by the cyst, and 2) relatively longer duration of paresis--only one case had paresis for under 2 years (mean 4.8 years) compared with only two cases for over 1 year (mean 2 years) in those with good recovery.

Posttraumatic pseudomeningomyelocele (enlarging fracture?) in a vertebral body. Case report

An unusual case is reported in which a posttraumatic peudomeningomyelocele developed over many years inside the body of a fractured lumbar vertebra, eroding the pedicle and causing progressive neurological deficit. The wall of the sac was mostly formed by the scalloped bar bone, and partly by a membrane resembling the dura. The terminal part of the conus medullaris and some nerve roots of the cauda equina formed the contents and parts of the wall of the outpouching of the subarachnoid space into the vertebral body. A comparison is drawn between this lesion and formation of an "enlarging fracture" of the skull. The surgical technique used for obliteration of this pseudomeningomyelocele is described.

Multiple meningeal diverticula and cysts associated with duplications of the sheaths of spinal nerve posterior roots

Multiple diverticula and cysts of the meninges were found during an anatomical dissection. They were associated with duplications of sheaths of the posterior roots of the spinal nerves. The diverticula and cysts appeared as simple flaccid corrugated dilatations of the sheaths, as ampullary expansions, as pediculated cysts, or as saccular dilatations of different sizes and locations. The duplication of the sheaths affected posterior roots of the thoracic nerves only. Some variations of the sheaths described in the literature are discussed. The possibility is considered that both conditions result from the same pathological factors in the embryo.

Recurrent intraspinal arachnoid cyst treated with a shunt procedure

A case of a recurrent arachnoid cyst in the thoracic region in a 13-year-old boy is reported. At the first operation, complete removal of the cyst proved impossible. At a second operation four years later, it was still impossible to remove the cyst so we performed a shunt procedure with drainage through a Hakim valve to the right atrium. This procedure was successful, resulting in complete disappearance of symptoms. In the presence of recurrent intraspinal cysts the authors recommend this treatment, as it is an easy operation which does not cause undue discomfort to the patient.

Septum posticum cysts: an uncommon cause of chronic back pain

The authors describe two patients with posterior thoracic pain associated with cysts of the septum posticum. One patient's pain was relieved by surgical removal of the cysts; the second patient's symptoms temporarily resolved after myelography. Posterior thoracic pain can be ascribed to myelographically proven arachnoid cysts when the pain is persistent, positionally exacerbated and associated with radicular sensory changes. Excision of the cysts may provide pain relief for some patients.

Spinal arachnoid cysts. Report of six cases

✓ Six cases of symptomatic spinal arachnoid cysts are presented. All lesions but one were intradural. Although these cysts are frequently indistinguishable clinically from spinal cord tumors, their correct early diagnosis by myelography and treatment by excision or marsupialization gives gratifying results. The authors emphasize that precise diagnosis and definitive treatment are sometimes delayed because of intermittent symptoms.

Spinal arachnoid diverticula

✓ Four cases of symptomatic arachnoid diverticula are presented to illustrate the diagnosis, radiographic findings, and treatment of this condition. The myelographic demonstration of asymptomatic diverticula is not rare, and only when neurological symptoms are localized to the level of the myelographically demonstrated diverticula is surgical treatment considered. Supine and upright positions during myelography are important to demonstrate the lesions.

Congenital spinal arachnoid cysts; report of two cases and review of the literature

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