Symptomatic spinal intradural arachnoid cysts in the pediatric age group: description of three new cases and review of the literature

Unusual presentation of cervical spinal intramedullary arachnoid cyst in childhood: case report and review of the literature

The authors report a 7-year-old girl who presented with progressive quadriparesis which had started a month before admission. Magnetic resonance imaging of the spine revealed an intramedullary cystic lesion extending from C(2) to C(4). After performing a C(2-5) laminectomy, the cyst was drained and anatomically fenestrated with the subarachnoid space by a 1-cm vertical median myelotomy without using a stent. The histopathological findings revealed arachnoid cyst. In the first month after operation, the neurological deficits disappeared gradually, except for a slight left upper paresis. Cervical spinal intramedullary arachnoid cyst is extremely rare and should be considered in the differential diagnosis of intramedullary cystic lesions in childhood. Recovery is possible after subtotal excision and fenestration of the cyst to allow communication with the subarachnoid space even if neurological deficits are present for a long time.

Extradural spinal arachnoid cysts associated with spina bifida occulta

INTRODUCTION

Spinal extradural arachnoid cysts are an uncommon cause of neural compression in children. Even more uncommon is the association of such cysts with spina bifida occulta.

MATERIAL

Two girls, 12 and 8-years-old, presented with left leg pain, deteriorating gait, clinical signs of left L5 and S1 root compression, without bladder or bowel symptoms. The first patient had left foot drop. The second patient had muscle wasting and smaller left foot with pes cavus. Radiographs showed spina bifida occulta of S1 in both. MRI revealed an extradural cyst at the S1 level, indenting the thecal sac and the L5 and S1 roots. At operation in both patients a large arachnoid cyst arising from a small dural defect in the axilla of the left S1 root was compressing and displacing it and the dural sac. It was removed and the defect was repaired. The first patient improved with complete recovery of the foot drop. An MRI at 12 months showed no cyst recurrence. The second patient made good recovery initially, but at 10 months developed recurrent symptoms. An MRI scan showed recurrence of the cyst with root compression. On repeat exploration a different dural defect was identified in a more anterior position and was repaired.

DISCUSSION

The coexistence of extradural arachnoid cyst and corresponding bifid spinal segment has not been described previously. It raises the suspicion that the dural defect giving rise to the arachnoid cyst may be due to segmental dural dysgenesis in the context of the dysrhaphic neuroectodermal malformation.

Ventral extradural spinal meningeal cyst causing cord compression: neurosurgical treatment

Spinal extradural meningeal cysts are typically formed by a thin fibrotic membranous capsule, macroscopically similar that of an arachnoid membrane, filled by cerebro spinal fluid and related to a nerve root or to the posterior midline. Ventral location is extremely rare and when it occurs they usually cause spinal cord herniation through the ventral dural gap. A 61 year-old man who began with a two years long history of insidious tetraparesis, spasticity and hyperreflexia in lower extremities, and flaccid atrophy of upper limbs, without sensory manifestations, is presented. Investigation through magnetic resonance imaging demonstrated an extensive spinal ventral extradural cystic collection from C6 to T11. The lesion was approached through a laminectomy and a cyst-peritoneal shunt was introduced. The cyst reduced in size significantly and the patient is asymptomatic over a 48 months follow-up. This is the first reported case of a spontaneous ventral extradural spinal meningeal cyst causing cord compression. Cyst-peritoneal shunt was effective in the treatment of the case and it should be considered in cases in which complete resection of the cyst is made more difficult or risky by the need of more aggressive surgical maneuvers.

Neurogenic bladder in an infant due to spinal arachnoid cyst

The urinary bladder of patients with occult spinal defects may become dysfunctional, exposing the renal parenchyma to irreversible damage. However, during infancy clinical signs are often misdiagnosed. The treatment should be aimed at protecting kidneys from severe bladder dysfunction. We report a case of a female infant with an arachnoid cyst diagnosed at the age of 6 months, who suffered from intractable, repeated febrile urinary tract infections (UTI) for the previous 3 months. The images obtained by ultrasonography and voiding cystoureterography techniques were typical of a neurogenic bladder. The spinal cord was examined by magnetic resonance imaging (MRI), which revealed an arachnoid cyst that was surgically treated when the child was 8 months old. The postoperative results were excellent: spinal cord MRI was normal after 1 year, and the child experienced only one UTI episode in the next 2 years. Such an etiology of neurogenic bladder has never been reported in a 6-month-old child.

MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis

Secondary intradural arachnoid cyst involving the spine is uncommon. It is usually secondary to trauma, haemorrhage, surgery or inflammation. We present two cases of treated tuberculous meningitis, which presented with gradual onset of quadriplegia and paraplegia, respectively. MRI revealed intradural (cervical and thoracic) arachnoid cysts (ventral and dorsal to the spinal cord) with myelomalacic cord changes. Ventral location of such spinal arachnoid cysts, and being secondary to tuberculous arachnoiditis are distinctively uncommon features. The rarity of this condition and the relevance of MRI in the accurate diagnosis have been discussed here.

Surgical experience in symptomatic congenital intraspinal cysts

Symptomatic congenital intraspinal cysts are uncommon but not rare. Since these cysts may have various manifestations, a careful differential diagnosis is needed. We retrospectively reviewed findings in 3 women and 2 men (age range, 10-50 years) with 6 symptomatic cysts of the thoracic or thoracolumbar spine. In addition, we statistically analyzed the patients' Nurick myelopathy grades before and after treatment. Pain and spastic paraparesis were the most frequent manifestations. Radiographs showed the widening of the spinal bony canal in 3 patients with extradural arachnoid cysts. All patients received limited laminectomy and appropriate surgical procedures. Pathology reports indicated neurenteric (n = 1), arachnoid (n = 4), and epidermoid (n = 1) cysts. Their functional status significantly improved by a mean of 2.6 Nurick points (p = 0.0002). Our findings confirm that these cysts have various manifestations. Congenital intraspinal cyst should be included in the differential diagnosis for patients with back pain, radiculopathy, cauda equina syndrome, Brown-Sequard syndrome, or myelopathy. The advent of MR imaging and increased knowledge about the pathogenesis of these cysts have improved the ease and accuracy of their early diagnosis; in addition, postoperative prognoses are excellent if surgery is performed early.

Spinal cord compression caused by extradural arachnoid cysts. Clinical examples and review

Most spinal arachnoid cysts are asymptomatic and detected incidentally during magnetic resonance imaging or myelography. The etiology of intraspinal arachnoid cyst is not yet clear. We present two children with three spinal extradural arachnoid cysts and each cyst protruded from a separate dura defect. In both patients, plain radiographs demonstrated widening of the interpedicular distance, which suggested progressive widening of the spinal bony canal. Limited laminectomy was performed to remove the intraspinal cysts. Separate dura defects, the apparent predisposing factors, were also found and repaired. The patients completely recovered neurologically. Radical cyst removal and dura defect closure are the surgical intervention of choice in patients with symptomatic extradural arachnoid cyst.

Extensive intradural arachnoid cyst of the lumbar spinal canal: case report

BACKGROUND

Spinal intradural arachnoid cysts are rare outpouchings of arachnoid lining occurring mainly in the thoracic and cervical regions. MRI is considered the diagnostic procedure of choice; however, some arachnoid cysts have been reported to elude diagnosis by MRI due to the similar signal intensity of the cyst and the subarachnoid space.

CASE DESCRIPTION

We present a case of a 41-year-old woman with an intradural arachnoid cyst of the lumbar spinal canal. Diagnostic studies demonstrated a herniated L4-5 disk, which led to two operations. Despite intractable pain postoperatively, the MRI failed to reveal further focal compression of the nerve root. A myelogram suggested compression of the thecal sac by a dorsal mass lesion. The patient underwent a midline durotomy that revealed two large arachnoid cysts with the nerve roots beneath them pushed ventrally and to the right. Removal of the arachnoid layer resulted in complete fenestration of the cyst and allowed the nerve roots to freely float in the spinal fluid.

CONCLUSION

In retrospect, the abnormality could be appreciated on multiple prior scans performed at another institution, demonstrating that in the patient with low back pain, degenerative disc disease is not the only diagnosis to consider.