Syringomyelia Associated with a Spinal Arachnoid Cyst

While syringomyelia is not a rare spinal disorder, syringomyelia associated with a spinal arachnoid cyst is very unusual. Here, we report a 62-year-old man who suffered from gait disturbance and numbness of bilateral lower extremities. Spinal magnetic resonance imaging (MRI) showed the presence of a spinal arachnoid cyst between the 7th cervical and 3rd thoracic vertebral segment and syringomyelia extending between the 6th cervical and 1st thoracic vertebral segment. The cyst had compressed the spinal cord anteriorly. Syringomyelia usually results from lesions that partially obstruct cerebrospinal fluid flow. Therefore, we concluded that the spinal arachnoid cyst was causing the syringomyelia. After simple excision of the arachnoid cyst, the symptoms were relieved. A follow-up MRI demonstrated that the syringomyelia had significantly decreased in size after removal of the arachnoid cyst. This report presents an unusual case of gait disturbance caused by syringomyelia associated with a spinal arachnoid cyst.     

Familial spinal arachnoiditis with secondary syringomyelia: clinical studies and MRI findings

We report the clinical and MRI findings of two patients with familial spinal arachnoiditis. Although their initial symptoms were various, they both showed spastic paraparesis and sensory disturbance below the thoracic level. Cytokines and WBC in the CSF were studied, but they were not elevated at all. The spinal magnetic resonance images of each showed extensive arachnoiditis and a cystic structure. The other impressive features included: (i) an enhancement within the thickened arachnoid and an adhesion between the spinal cord and the dura mater, (ii) deformation of the thoracic cord where the arachnoid adhered, and (iii) secondary syrinx formation. Laminectomy may have an adverse outcome for such patients.     

Diagnosis of syringomyelia and its classification on the basis of symptoms, radiological appearance, and causative disorders

Although it is easier to accurately diagnose syringomyelia with the advent of magnetic resonance (MR) imaging, syringomyelia still poses challenges to clinicians because of its complex symptomatology, uncertain pathogenesis and multiple treatment options. Here, we propose criteria for classification of syringomyelia not related to those associated with spinal intramedullary tumors. The classification aims to distinguish between the presyrinx state and syringomyelia, between asymptomatic and symptomatic syringomyelia and to clarify the associated disorders such as Chiari malformations, spinal arachnoiditis and spinal cord trauma. Diagnostic criteria for Chiari I and II malformations with MR imaging were also defined. Several hypotheses proposed to explain the pathogenesis of syringomyelia associated with Chiari I malformation were reviewed. A questionnaire survey on syringomyelia based on the proposed criteria conducted between November 2009 and April 2010 in Japan revealed that 160 (22.6%) of the 708 patients were asymptomatic. Chiari I malformation was the most frequent causative disorder (48.3%), followed by spinal arachnoiditis (15.8%). The proposed criteria for classification of syringomyelia will facilitate a nationwide survey of syringomyelia in Japan. Such a survey will inform us of its prevalence and prognosis more precisely, and enable us to build a reliable database that may help determine the optimal treatment for the disease in the future.     

Novel surgical management of spinal adhesive arachnoiditis by arachnoid microdissection and ventriculo-subarachnoid shunting

Spinal cord tethering and cerebrospinal fluid (CSF) flow disturbance are two major features in the pathophysiology of spinal adhesive arachnoiditis. We hypothesized that insufficient CSF supply to the surgically untethered spinal cord may be one of the causes of the typical post-operative recurrent extensive lesion. We report a patient with extensive spinal adhesive arachnoiditis, who was successfully treated using a novel surgical technique consisting of two procedures. First, microdissection of the thickened adherent arachnoid was performed to resolve spinal cord tethering. Next, a ventriculo-subarachnoid shunt was placed to provide sufficient flow of CSF. Clinical improvement was sustained for at least 22 months after surgery. The present surgical procedure may improve clinical outcome in patients with longitudinally extensive spinal adhesive arachnoiditis.     

Arachnoiditis ossificans with progressive syringomyelia and spinal arachnoid cyst.

We present a 30-year-old man with progressive spastic paraparesis. Spinal imaging revealed extensive calcification of the thoracic cord and cauda equina arachnoid, an intradural extramedullary cyst and evidence of rapidly progressing syringomyelia. Radiological diagnosis was arachnoiditis ossificans and an attempt at surgical decompression was made because of progressive neurologic deterioration. Due to tenacious adhesion of the calcified plaques to the cord and roots, only cyst drainage was achieved; the patient had no clinical improvement. A literature review revealed only two other cases reported in the literature with co-existence of arachnoiditis ossificans and syringomyelia. In none of the previous cases was there an intradural extramedullary arachnoid cyst, nor did the syrinx progress in such a rapid fashion. An attempt is made to explain possible pathophysiological mechanisms leading to this unusual pathology.     

脊髓蛛网膜炎合并脊髓空洞的显微手术治疗

目的探讨脊髓蛛网膜炎合并脊髓空洞的显微手术治疗方法。方法回顾性分析经显微外科手术治疗的15例脊髓蛛网膜炎合并脊髓空洞病人的临床资料。根据脊髓蛛网膜炎症黏连的特点分为3型：I型（弥漫黏连型）10例,Ⅱ型（局限黏连型）3例,Ⅲ型（囊肿型）2例。I型行脊髓空洞一胸腔分流术,Ⅱ型行脊髓黏连松解术,Ⅲ型行囊肿探查切除术。结果术后症状明显改善13例,同术前2例。MRJ复查显示：脊髓空洞缩小12例,消失1例,同术前2例。13例术后随访8个月～3年,症状改善9例,同术前3例,加重1例。结论显微手术是治疗脊髓蛛网膜炎合并脊髓空洞的有效方法,根据分型选择合适的显微手术治疗方案,治疗效果较好。     

Surgical management of syringomyelia associated with spinal adhesive arachnoiditis.

The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.     

Spinal syringomyelia following subarachnoid hemorrhage

Subarachnoid blood has been reported as a cause of chronic spinal arachnoiditis. Although syringomyelia has been thought to be caused by spinal arachnoiditis, reports of syringomyelia following aneurysmal subarachnoid hemorrhage (SAH) are very rare. We describe two patients with syringomyelia associated with chronic spinal arachnoiditis following SAH. From January 2001 to December 2010, 198 patients with aneurysmal SAH were treated at Kinki University School of Medicine. Two of the 198 patients had syringomyelia following aneurysmal SAH; thus the rate of syringomyelia associated with aneurysmal SAH was 1.0%. Patient 1 was a 54-year-old woman who presented with back pain, back numbness and gait disturbance 20 months after SAH. Her MRI revealed syringomyelia of the spinal cord from C2 to T10. She underwent shunting of the syrinx to the subarachnoid space. Patient 2 was a 49-year-old man, who was admitted to the hospital with headache, diplopia, hoarseness, dysphagia and ataxia five months after SAH. MRI revealed syringomyelia from the medulla oblongata to C6, and an enlargement of the lateral and fourth ventricles. After foramen magnum decompression and C1 laminectomy, a fourth ventricle-subarachnoid shunt was placed by insertion of a catheter. Spinal arachnoiditis and spinal syringomyelia are rare but important chronic complications after SAH.     

Theoretical analysis of the pathophysiology of syringomyelia associated with adhesive arachnoiditis

OBJECTIVE: To apply a theoretical model to analyse the derangement of cerebrospinal fluid (CSF) dynamics in syringomyelia associated with adhesive arachnoiditis. METHODS: An electrical circuit model of CSF dynamics in the spine was used. With this model, the derangement of CSF dynamics in adhesive arachnoiditis was simulated. The effects of various surgical procedures were then analysed, such as syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression. RESULTS: When CSF flow in the subarachnoid space was obstructed at a certain point, the pressure inside the spinal cord increased in the segment immediately distal to the blockage. This location of increased pressure corresponded to the preferred site of syrinx formation in adhesive arachnoiditis. Syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression were all effective at reducing this pressure gradient. CONCLUSIONS: Blockage of the spinal subarachnoid CSF pathway produces a relative increase in the pressure inside the spinal cord distal to the blockage point. Repetitive formation of this pressure gradient then induces CSF leakage into the spinal parenchyma, leading to the formation of syringomyelia. Using this model, alternative surgical procedures could be suggested that might be effective in treating this disease.     

A case of split notochord syndrome: An adult with a spinal endodermal cyst mimicking an intramedullary tumor

Intraspinal endodermal cysts are very rare congenital cysts, usually composed of a thin‐walled cyst the lining of which mimics gastrointestinal or respiratory epithelium. Diagnosis is usually established during the first or second decade of life. These cysts are frequently associated with vertebral or spinal cord abnormalies and dual malformation with mediastinal or abdominal cysts. Collectively, they are called split notochord syndrome. The authors describe their experience in the treatment of a 57‐year‐old man having an endodermal cyst mimicking an intramedullary tumor at the level of Th1‐2. He was admitted to our institution for evaluation of an intraspinal mass diagnosed by MRI at a local hospital after experiencing temporary numbness and weakness of the lower left extremity. T1‐weighted sagittal MRI demonstrated the lesion with signal intensity iso‐ to slightly hypointense to the spinal cord without enhancement after administration of gadolinium. Although T2‐weighted sagittal images demonstrated as hyperintense to the spinal cord, axial images revealed a passage between the mass and subarachnoid space. We could not completely rule out the presence of an intramedullary tumor and undertook a laminectomy with a posterior approach. Histopathological analysis revealed an endodermal cyst and the authors found syringomyelia, which was clearly separated from the cyst in the preoperative sagittal MRI and intraoperative ultrasonography study. To the best of our knowledge, this is the first report in the English literature of a thoracic endodermal cyst requiring differential diagnosis from a spinal cord tumor.     

Intramedullary spinal cord metastasis documented by MR imaging

A 63-year-old woman with progressive paraparesis was found to have an intramedullary spinal cord metastasis from the primary rectal cancer. Myelography and post myelography CT showed an enlargement of the spinal cord at level of the sixth to seventh thoracic vertebra. MR imaging disclosed a localized mass in the spinal cord at the same level. T2-weighted images showed an oval high signal intensity area with central low intensity, and gadolinium-DTPA-enhanced T1-weighted images demonstrated a ring enhancement. Histological examination of the spinal cord revealed an intramedullary spinal cord metastasis with intra-tumorous necrosis at T7 to T8 cord level.     

Syringomyelia and hydromyelia: Current understanding and neurosurgical management

Syringomyelia is a rare disorder in which a fluid-filled cyst forms within the spinal cord, resulting in myelopathy. Meanwhile, the abnormal dilatation of the central canal is referred to as hydromyelia or slit-like syrinx. The most prevailing classification is based on anatomical features and pathogeny rather than pathophysiological mechanisms. It is usual to distinguish foraminal syringomyelia related mainly to abnormalities at the craniocervical junction, non-foraminal syringomyelia dealing with any cause of arachnoiditis (infection, inflammation, trauma…) and more rarely syringomyelia associated with intramedullary tumors. Although many pathophysiological theories have been argued over time, the prevailing one is that disturbances in cerebrospinal fluid (CSF) flow in the sub-arachnoid spaces disrupt flow velocity leading to the syrinx. Symptoms of paralysis, sensory loss and chronic pain commonly develop during the third/fourth decades of life. The natural history of syringomyelia is typically one of gradual, stepwise neurological deterioration extending over many years. Diagnosis is based on magnetic resonance imaging (MRI) including excellent morphological sequences (T1-, T2-, FLAIR-, T2*-, enhanced T1-) and dynamic MRI with careful study of CSF velocity (CISS, cine-MR sequences). Surgical management is at first dedicated to treat the cause of the syringomyelia, mainly to re-establish a physiological CSF pathway in the subarachnoid spaces. Mostly, the surgical goal is to enlarge the craniocervical junction with duraplasty. Other surgical strategies such as arachnoidolysis or shunt procedures are performed based on the pathogenic mechanisms or as second-line treatment. Medical treatments are also necessary as chronic pain is the main long-lasting symptom. As evolutive syringomyelia is a severe disease with a high impact on quality of life, it is recommended to treat without delay. There is no evidence for surgery for incidental asymptomatic syringomyelia or hydromyelia. Finally, syringomyelia associated with intramedullary tumors resolves spontaneously after tumor resection. Syringomyelia is a rare disease, which requires a dedicated multidisciplinary approach, emphasizing the need for a nationwide scientific organization so as to offer optimal care to the patient.     

Syringomyelia and arachnoiditis.

Five patients with chronic arachnoiditis and syringomyelia were studied. Three patients had early life meningitis and developed symptoms of syringomyelia eight, 21, and 23 years after the acute infection. One patient had a spinal dural thoracic AVM and developed a thoracic syrinx 11 years after spinal subarachnoid haemorrhage and five years after surgery on the AVM. A fifth patient had tuberculous meningitis with transient spinal cord dysfunction followed by development of a lumbar syrinx seven years later. Arachnoiditis can cause syrinx formation by obliterating the spinal vasculature causing ischaemia. Small cystic regions of myelomalacia coalesce to form cavities. In other patients, central cord ischaemia mimics syringomyelia but no cavitation is present. Scar formation with spinal block leads to altered dynamics of cerebrospinal fluid (CSF) flow and contributes to the formation of spinal cord cystic cavities.     

Experimental syringomyelia in rabbits and rats after localized spinal arachnoiditis]

In order to produce syringomyelia, localized arachnoiditis was created in adult New Zealand albino rabbits and Wistar rats by the injection of kaolin into the thoracic spinal subarachnoid space and incision of the dura mater of the thoracic spinal cord. The rabbits and rats were divided into 3 groups; the control group, dural incision group (DG) and kaolin injection group (KG). Each rabbit was sacrificed at 4, 8, 12 and 16 weeks after the operation. Each rat was sacrificed at 8 and 16 weeks after the operation. Cavity formation in the cord of all rabbits was examined by ultrasound. All animals were perfused with 10% neutral beffered formalin at 150 cm H2O pressure, and histological examination was performed with Luxol fast blue (LFB) and hematoxylin and eosin (H&E) stains. Results obtained: (1) Cavity formation was noted in 6 of 16 DG of rabbit (37.5%), 5 of 16 KG of rabbit (31.2%) and 2 of 9 KG of rat (22.2%) with histological verification. With use of ultrasound, cavity was noted in 3 of 16 DG rabbits (12.5%) and 2 of 16 KG rabbits (18.8%). (2) Cavity formation was present in the cord adjacent to the marked adhesive arachnoiditis both in rabbits and in rats. (3) Cavity was noted in the ischemic area. (4) In 2 rabbits in which kaolin encircled whole surface of the spinal cord, hydromyelia was formed communicating with enlarged central canal caudad from the kaolin subarachnoid block. (5) Histological examination showed obliteration or narrowing of lumen of the small pial vessels involved in the adhesive arachnoiditis. In the cord parenchyma adjacent to the arachnoiditis, multiple spots of demyelination due secondary to ischemia demonstrated by LFB stain were noted. On the other hand, in the cord with the pia-arachnoid remained uninvolved, no demyelination was observed. (6) Localized adhesive arachnoiditis consisted of proliferation of fibrous tissue, lymphocytic infiltration and obliterating processes of small pial vessels involved in it. These data suggest that the cavitation within the cord would be induced by the ischemia, and hydromyelia would be produced by the pressure dissociation between the spinal subarachnoid space and the central canal.     

颈髓髓内血管母细胞瘤的诊断与治疗

目的 探讨颈髓髓内血管母细胞瘤的诊断与治疗。方法 分析19例患者的MRI表现，及其手术治疗的效果。结果 这类肿瘤在MRI上可分为三型：A.空洞型，肿瘤大小不等，且继发延、脊髓空洞；B.囊肿型，为囊内小的附壁结节；C.实体型，为巨大的实体性肿瘤。所有患者均经手术全切除肿瘤，并经病理证实为血管母细胞瘤。术后患者神经系统状态好转者18例，加重1例。结论 颈髓MRI能对颈髓髓内血管母细胞瘤作出定位、定性诊断，并可将其分型，以利选择不同的手术方法；诊断时，还需与胸廓出口综合征和颈椎病相鉴别。认为颈髓髓内、即使累及延髓的血管母细胞瘤宜行积极手术治疗；手术方法随肿瘤类型不同而各异，最为重要是：需沿正确的界面分离，并应在离断供血动脉后切除肿瘤。     

A case of idiopathic thoracic spinal cord herniation]

We report a case of idiopathic thoracic spinal cord herniation. A 63-year-old female came to our hospital complaining of a slowly progressive gait disturbance that began 5 years ago. She showed signs of a left dominant spastic paraparesis and sensory disturbance. Her left foot had already became a drop foot from 2 years ago. Magnetic resonance (MR) imaging and computed tomographic (CT) myelography demonstrated that the atrophic spinal cord had displaced to the ventral side with a dilated dorsal subarachnoid space at T2-3 level. Surgery was performed via T2-3 laminoplastic laminectomy. The ventral aspect of the spinal cord revealed a defect in the inner layer of the duplicated dura mater, into which the gliotic spinal cord herniated. The herniated spinal cord was repositioned and the dural defect was repaired using a GORE-TEX dura substitute. Postoperative course was uneventful. Although the patient showed marked improvement in the right lower limb, there was slight improvement in the left lower limb. The clinical symptoms of this disease are uncommon and progress slowly, and if left untreated will result in paraparesis. Therefore early diagnosis and operation is important to prevent the progression of symptoms and to achieve a satisfactory outcome.     

Retrocerebellar arachnoid cyst with syringomyelia: a case report

Association of syringomyelia with retrocerebellar arachnoid cysts is rare. A case of 14 year old female is being reported, who presented with hydrocephalus caused by a large midline retrocerebellar infravermal arachnoid cyst leading to obstruction of the outlet foramina of the fourth ventricle. There was associated syringomyelia. The pathogenesis of syringomyelia is discussed. The need to evaluate cervical spinal cord by taking T1 weighted sagittal sections in all the patients of large posterior fossa mass lesions causing obstruction to the outlet foramina of the fourth ventricle has been stressed, in order to detect associated syringomyelia.     

Syringomyelia: cyst measurement by magnetic resonance imaging and comparison with symptoms, signs and disability.

The severity and distribution of symptoms and signs in patients with syringomyelia is considered to be dependent on the longitudinal and transverse dimensions of the syrinx and it is thought that clinical examination can identify the extent of the cyst. Magnetic resonance imaging has made the anatomical localisation of intramedullary spinal lesions more exact and probably more specific than previous methods of investigation. Syrinx length, diameters, cyst:cord and cord:canal ratios have been studied in 12 patients with syringomyelia to assess whether the dimensions of the syrinx relate to the clinical findings. The length of syrinx appeared to be related to cyst diameter, cyst:cord and cord:canal ratios. Patients with a small syrinx tended to have a small cyst diameter, and small cyst:cord and cord:canal ratios. No significant relationship was found between muscle wasting or weakness, distribution of sensory loss, degree of disability or distress and the dimensions of the syrinx. These findings should be borne in mind when surgical management is being considered.     

An arachnoid cyst presenting as an intramedullary tumour

A case of thoracic intradural extramedullary arachnoid cyst is presented in which an intramedullary low grade glioma was suspected preoperatively. The cyst was widely fenestrated and postoperatively, the patient experienced considerable improvement in her symptoms. As postoperative MRI studies also showed resolution of the intramedullary changes we regard the intramedullary changes as a result of the cyst, without the existence of primary medullary pathology. To our knowledge an arachnoid cyst, to date, has not been described as the cause of syringomyelia. As radiological findings can be misleading, extramedullary pathology, located more cranially, should be ruled out when treating cystic medullary changes.     

Intradural extramedullary tumor of lower spinal cord in a 89-year-old man with cervical spondylosis and lumbar spondylolisthesis

A 89-year-old man was admitted because of slowly progressive gait disturbance during these several years. Neurological examination revealed paraparesis with bilateral sensory disturbance in the lower extremities, more severely on the left side. Vibration sense was almost completely disturbed under the level of bilateral crista iliaca. Deep tendon reflexes decreased in the lower extremities. No urinary incontinence was observed. The narrow spinal canal and cervical spondylosis were seen at the C 5-6 level, showing the anterior-posterior distance of 10 mm. Computed tomography of the lumbar spine showed spondylolisthesis between the level 4 and 5. CSF showed high protein concentration (300 mg/dl), whereas normal cell counts. These findings suggested the following two possibilities; cervical myelopathy associated with the disturbance of the cauda equina due to lumbar spondylolisthesis, or the disturbance at the lower thoracic or upper lumbar level of spinal cord. The spinal MRI revealed the irregular mass lesion in the lower spinal cord at the level of spine Th 11-12 on T2 weighted images, with enhancement by Gd-DTPA on T1 weighted images. These MRI findings suggested the intradural extramedullary tumor, such as benign neurinoma or meningioma. No clear cut lesions were found at the cervical spinal cord or at the cauda equina. MRI was useful for the diagnosis of sites and lesions of spinal cord in the present case, whose neurological signs and symptoms could be explained by the coexistent cervical spondylosis and lumbar spondylolisthesis.