High-resolution constructive interference in steady-state imaging in tethered cord syndrome: technical note

BACKGROUND: Differentiation between nerve roots and the tethered filum terminale in magnetic resonance images remains challenging. It is, however, crucial to select patients for surgical intervention. METHOD: In 1 patient with progressive and 2 patients with stable clinical signs of tethered cord syndrome (TCS), images reconstructed from a 3D constructive interference in steady-state (CISS) sequence were compared with those obtained from a regular T2-weighted fast spin echo sequence. RESULTS: Nerve roots of the cauda equina were suppressed, whereas visualization of the filum terminale was much improved in high-resolution CISS sequences. In addition, the level of adhesion of the filum could be localized in relation to elements of the spinal cord. The imaging results were confirmed during surgery and the patient improved considerably after the intervention. The advantages of CISS were also apparent in 2 other patients who are still being observed. CONCLUSION: Constructive interference in steady-state imaging should be considered in the presurgical routine for patients with TCS.     

Intraoperative mapping of sacral nervous system (S2-4)

Electrophysiological mapping of the sacral nervous system was used during operations on 80 patients with conus and cauda equina lesions. At surgery, under controlled muscle relaxation, the sacral neural elements (S2-4) were mapped using direct mono-polar stimulation and recording of compound muscle action potentials (CMAPs) from the external anal sphincter (EAS). Responses were obtained in 86.25% (69/80) of the patients. In 33 (82.5%) out of 40 patients with preoperative deficits involving the S2-4 segments, CMAPs could be elicited. Identification of nerve roots was useful in dissection of lipomyelomeningocoeles, tumour excisions and untethering of filum terminale. In three patients, stimulation of the filum terminale elicited motor responses and, hence, it was not sectioned. Intraoperative mapping of the S2-4 nerve roots under controlled muscle relaxation is feasible in a majority of patients, including those with deficits involving S2-4. This method was useful in sparing viable nerve roots during surgery in conus and cauda equina regions, and identification of 'functional' filum terminale.     

Correlation between magnetic resonance imaging and surgical findings in the tethered spinal cord

Between October 1982 and August 1987, 20 patients underwent magnetic resonance imaging (MRI) and subsequent surgical release of a tethered spinal cord. The tethering was caused by a thick filum terminale in 6 patients. On MRI scans, the conus medullaris was at L4 in 2 patients, at L2 in 3 patients, and the filum terminale appeared thick in 1 patient. The spinal cord was tethered to an intradural lipoma correctly demonstrated by MRI in 6 patients. Increased epidural fat was misdiagnosed as an intradural lipoma in one patient and a lipomatous stalk was not identified in 2 other patients. Scar tissue resulting from repair of a meningocele had tethered the cord in the remaining 8 patients. On MRI scans, the conus medullaris was located between L3 and S3; in 5 of the patients, scar tissue was apparent on the MRI scan. This correlative study supports the use of MRI as the initial, and possibly the only, imaging modality when a tethered spinal cord is suspected. Improved or more recent MRI techniques will help demonstrate these anomalies better.     

Intraoperative electrophysiologic studies on the functions of nerve roots involved in cervical dumbbell-shaped schwannoma and their clinical utility

BACKGROUND: It is difficult to expect the degree of neurologic deficits after resection of involved nerve roots before and during the surgery for cervical dumbbell-shaped schwannoma. We present the results of studies for cervical nerve root functions in patients with cervical schwannoma using intraoperative electrophysiologic assessment and the potential of their clinical relevance is also discussed. OBJECTIVE: To present the utility of intraoperative electrophysiologic studies to detect the functions of the nerve roots involved in cervical schwannoma and adjacent nerve roots. METHODS: Five patients with dumbbell-shaped cervical schwannoma arising from the cervical nerve roots composing the brachial plexus were studied. Compound muscle action potentials (CMAPs) after stimulation of nerve roots involved in the schwannoma were recorded from upper limb muscles anatomically correspond to their myotome. Adjacent nerve roots were also stimulated. Motor-evoked potentials (MEPs) after transcranial electric stimulation were also recorded during surgery. In 3 patients, sensory nerve action potentials (SNAPs) after digital nerve stimulation were also recorded from cervical nerve roots. RESULTS: In 4 patients, CMAPs after stimulation of cervical nerve roots involved with the schwannoma were not obtained or were very small compared with those obtained after stimulation of adjacent nerve roots. In 2 of 4 patients, SNAPs after digital nerve stimulation were recorded with small amplitude from the nerve roots involved in schwannoma. Minimal (n=2, within 80% attenuation of amplitude) or no changes (n=2) were observed after total resection of the schwannoma and no apparent motor weakness occurred in these 4 patients. In a patient with cervical schwannoma involved in C8 nerve root, CMAPs with large amplitude were recorded after stimulation of the C8 nerve root. SNAPs after stimulation of digit V were recorded with larger amplitude from the T1 root compared with those recorded from the C8 nerve root. Intradural parts of the tumor arising from C8 posterior rootlets were completely removed after transaction of posterior rootlets. During removal of intraforaminal parts of the tumor, motor evoked potentials were decreased over 50% of controls. Incomplete removal was chosen to avoid deterioration of motor function. Transient dysesthesia of digit V and slight weakness occurred after surgery. CONCLUSIONS: The residual function of motor and sensory nerve roots involved with cervical schwannoma differed between individuals and could be detected using intraoperative electrophysiologic assessment.     

Continuous EMG recordings and intraoperative electrical stimulation for identification and protection of cervical nerve roots during foraminal tumor surgery

OBJECTIVE: Spinal cord function is now routinely monitored with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) during surgery for intraspinal cervical dumbbell and foraminal tumors. However, upper extremity nerve roots are also at risk during these procedures. Anatomic relations are frequently difficult to interpret because the nerve roots may be displaced by the tumor. We used electrical stimulation with compound muscle action potential (CMAP) recordings at multiple sites to identify the location and course of the involved nerve root and to provide real-time information regarding the functional status of the roots to predict postoperative outcome. METHODS: Ten patients were monitored during surgery for cervical dumbbell or foraminal tumors. SEPs and MEPs were monitored as a routine procedure. CMAPs were recorded from needle electrodes placed in the deltoid, biceps, triceps, and flexor carpi ulnaris muscles. Spontaneous electromyography (EMG) muscle activity was also continuously monitored. A handheld monopolar stimulation electrode was used to elicit evoked EMG responses to identify and trace the course of nerves in relation to the tumor. In four patients, the stimulation threshold was tested before and after tumor resection to predict postoperative nerve root function. RESULTS: Electrical stimulation with CMAP recording was successful in localizing nerve roots during tumor resection in all 10 patients. Monitoring predicted postoperative nerve root preservation after tumor removal in each case. It was possible to identify either by using low-level stimulation (<2.0 V) or by observing changes in spontaneous EMG amplitude if activation was present during surgical dissection. The monitoring of spontaneous muscle activity in response to direct or indirect surgical manipulation during tumor resection also provided continuous assessment of nerve root function and identified any physiologic disturbance induced by surgical manipulation. CONCLUSIONS: Electrical stimulation in the operating field and recording of CMAPs facilitated nerve root identification and predicted postoperative function during dissection and separation from ligamentous or neoplastic tissue in 10 patients. Electrical stimulation might also be useful to predict postoperative preservation of function when nerve root sacrifice is necessary and no motor response is detected intraoperatively.     

Sectioning of filum terminale externum using a rigid endoscope through the sacral hiatus. Cadaver study

AIM: Tethered cord syndrome (TCS) is a stretch-induced functional disorder of the spinal cord, which is directly related to filum fixation. Classic surgical approaches to the filum involve open surgery and include varying amounts of spinal bone removal. In an effort to reduce the morbidity and mortality of these procedures, the authors explored a less invasive method. They evaluated the ability, safety and feasibility for endoscopic sectioning of the filum terminale externum by performing upward orientated navigation in the extradural sacral spinal canal through the sacral hiatus using a rigid endoscope. METHODS: Four adult, phenol-formalin embalmed cadavers were used for endoscopic section of the filum terminale externum at the tip of thecal sac. After preparing the anatomical area of sacral hiatus, a rigid endoscope (Storz, of 3.8 mm external diameter with two working channels, of 1 mm each, one for suction-irrigation and one as working) was inserted into the extradural sacral spinal canal and the filum terminale externum was identified and cut easily at the distal end of thecal sac at the level of S2. In all cases, it was possible to manipulate the rigid endoscope and inspect the full length of the extradural sacral spinal canal, especially at the S1-S2 level. RESULTS: The results indicate that the tested transhiatal approach for upward orientated extradural endoscopy represents a minimally invasive procedure that provides an appropriate and feasible route to the extradural sacral spinal canal. CONCLUSION: Such approach is an attractive alternative for filum terminale externum sectioning in cases where tethered cord syndrome is not accompanied by any other pathology. Moreover if filum terminale internum sectiong is indicated, it can be performed in second stage.     

Extensibility of the lumbar and sacral cord. Pathophysiology of the tethered spinal cord in cats

Tethered spinal cord, or tethered cord syndrome, describes a disorder manifested by progressive motor and sensory deficit in the legs and by incontinence. Tethered cord syndrome occurs when the elongated spinal cord is anchored by a thick filum terminale or other pathological structures. The underlying mechanism is impairment of oxidative metabolism in the lumbosacral cord. The authors studied the extensibility of various parts of lumbar, sacral, and coccygeal segments in experimental animals and correlated this with the oxidative metabolism in these segments. The filum terminale possesses far greater extensibility than any spinal cord segments and functions as a buffer in preventing the cord from overstretching. The lumbar, sacral, and coccygeal segments elongate under traction only below the attachment of the lowest pair of dentate ligaments. The lower the cord segment, the greater the percentage of elongation in spite of limited elasticity of the cord tissue; this greater percentage of elongation of the spinal cord correlates with increasing impairment of the oxidative metabolism and more severe neurological deficit. These findings explain such symptoms and signs as motor and sensory deficits in the legs associated with the human tethered cord syndrome, and correspond with the high clinical incidence of incontinence. The lower spinal cord segments elongated promptly within 3 seconds after the start of traction. This implies that repeated acute hyperextension and hyperflexion, as occurs in humans, may accentuate oxidative metabolic changes that have already been caused by chronic cord tethering. The authors conclude that the elongation of the spinal cord under traction parallels the degree of metabolic dysfunction.     

脊髓拴系综合征MRI图像与手术所见的关系

就２５例脊髓拴系综合征患者的核磁共振（ＭＲＩ）图像与手术中所见进行对比分析，所有病人皆有脊柱裂，其ＭＲＩ图像和手术所见完全相符。根据ＭＲＩ和手术所见，可将脊髓拴系综合征分为：（１）终丝粗大型，（２）脂肪瘤型，（３）术后瘢痕粘连型，（４）脊髓或马尾肿瘤型，（５）混合型等５种类型。文中就各类型病人的ＭＲＩ表现和手术中所见加以讨论。     

Adipose tissue in the filum terminale: a computed tomographic finding that may indicate tethering of the spinal cord

Adipose tissue in the filum terminale is frequently associated with tethering of the spinal cord in patients with spina bifida occulta. We recently saw a patient with low back pain and no spina bifida occulta, in whom adipose tissue was noted in the area of the filum on an unenhanced computed tomographic (CT) scan. The patient had a tethered cord. This case suggested that, when CT scanning is done as the first imaging study in the evaluation of low back pain, fatty tissue in the area of the filum may be an indicator for tethering of the spinal cord. The present study was undertaken to determine the validity of using CT scan-detectable filal fat in the identification of possible tethered spinal cords among a group of patients experiencing low back pain. The presence of fat in the fila of 12 patients with the radiologically and histologically tethered cord syndrome was evaluated and the fila of 47 autopsied patients whose clinical history showed no back pain were examined histologically. There were accumulations of adipose tissue in the fila of 11 of the 12 (91%) patients with the tethered cord syndrome and in the fila of 9 of the 47 patients (17%) in the autopsy series. Of the 9 autopsy patients with fat in their fila, however only 3 patients (6%) exhibited collections of adipose tissue in the CT detection range (2 mm).(ABSTRACT TRUNCATED AT 250 WORDS)     

Intraoperative electromyographic techniques for the decision-making of tumor-involved nerve root resection for treating spinal schwannomas

BACKGROUND CONTEXTTotal removal of spinal schwannomas is ideal but it sometimes requires tumor-involved root resection, which increases the risk of postoperative motor deterioration (PMD). Therefore, it is important for clinicians to predict the impact of tumor-involved root resection on motor function in spinal schwannomas.PURPOSETo investigate the role of intraoperative electromyographic (EMG) techniques in decision-making of tumor-involved root resection for treating spinal schwannomas.STUDY DESIGNA retrospective analysisPATIENT SAMPLESixty-eight patients with spinal schwannomas arising from C5-T1 or L3-S1 roots underwent total resection of schwannoma, including tumoral root.OUTCOME MEASURESNerve root activation threshold, free-running EMG signals, visual analogue scale, and American Spinal Injury Association scale.METHODSDuring evoked EMG, nerve root activation threshold for tumoral root stimulation was recorded from muscles anatomically corresponding to tumoral root. During free-running EMG, abnormal EMG signals were identified as irregularly recurrent, monomorphic signals, low frequency (<5 Hz) or absent discharges recorded from muscles innervated by tumoral root. Clinical assessments were performed before, 3 to 5 day's and six months’ after operation.RESULTSSixteen (16 of 68, 23.5%) patients showed PMD, and muscle strength improved or was not affected in the other 52 patients. Absent myogenic responses were observed in 19 patients with non–PMD, and nerve root activation threshold in non–PMD group was higher than that in PMD group (p<.05). Receiver operating characteristic curve revealed that cut-off value of nerve root activation threshold for distinguishing functional and nonfunctional roots was 11.8 mA. A larger number of patients without PMD than with PMD showed abnormal free-running EMG signals (p<.05). At postoperative 6-months’ follow-up, ten patients with muscle weakness after tumor-involved root resection showed functional recovery (full vs. partial recovery: 5 vs. 5), and intraoperative nerve root activation threshold in these patients was higher than that in the other patients without functional recovery (p<.05). Furthermore, there is negative relationship between the duration for full recovery and nerve root activation threshold (p<.05).CONCLUSIONSBoth evoked and free-running EMG can be used as supplementary tests for differentiating functional and nonfunctional tumoral roots in spinal schwannomas, and nerve root activation threshold may be also related to prognosis of patients with muscle weakness caused by tumor-involved root resection. Therefore, intraoperative EMG techniques may provide additional references in decision-making of tumor-involved root resection.     

Tethered cord syndrome in adults as a cause of disorders of bladder function

The histories of two adults with tethered cord syndrome are presented. Slowly increasing bladder dysfunction, dysraphic disorder and increasing sensorimotor deficits gave rise to the suspicion of tethered cord syndrome. The release of the cauda equina by transsection of the thickened filum terminale and in one case removal of lipomatous tissue in addition improved the bladder function and the sensorimotor function substantially. Diagnostic procedures and aspects of the prognosis are discussed.     

Role of intraoperative neurophysiologic monitoring in lumbosacral spine fusion and instrumentation: a retrospective study

BackgroundThis study was carried out to determine the efficacy of IONM in detecting iatrogenic neural injury during pedicle screw insertion, in comparison to the efficacy of computerized tomography (CT) and direct visual inspection of adjacent nerve roots.MethodsWe reviewed the records of 86 patients, who had had 414 titanium pedicle screws inserted for posterior lumbar instrumentation. A standardized multimodality technique under total intravenous anesthesia was used. A relevant neurophysiologic change (surgical alert) was defined as a reduction in amplitude of at least 50% for somatosensory evoked potentials or at least 65% for transcranial electric motor evoked potentials (tcMEPs) compared with baseline. A stimulation threshold of 8 mA or less indicated that the screw was too close to the nerve root.ResultsImmediate feedback via evoked electromyography (EMG) using stimulating pedicle probes in appropriate muscle groups was suggestive of pedicle cortical bone compromise in 28 screws (6.7%). Twenty-one screws were removed and redirected. Four false-positive evoked EMGs in 4 patients were detected by direct visual inspection of the nerve roots and the pedicles, and the surgeon elected not to reposition the screws. None of those patients had postoperative neurologic deficit, and the postoperative CT confirmed the integrity of pedicles. Three false-negative EMGs in 3 patients were detected postoperatively by new neurologic deficits and abnormal CT (3.48%).ConclusionIntraoperative neurophysiologic monitoring is a valuable tool to add to the surgical skill and intraoperative fluoroscopy to protect neural tissue during pedicle screw instrumentation. However, postoperative CT is the ultimate test to determine the accuracy of positioning of the titanium screws. We propose a wake-up test in the operating room after extubation and urgent CT if the patient develops a new neurologic deficit to determine whether to reposition the screws in the same setting.     

脊髓纵裂神经损伤的病理因素与治疗

目的 探讨脊髓纵裂病理因素及其神经损伤机制，选择合理的治疗方法。方法 根据70例脊髓纵裂患者的影像学资料，手术观察，尸解和临床表现，结合治疗方法与效果，研究其导致神经损伤的病理改变。结果 脊髓纵裂病理因素有5个方面；（1）先天性神经发育不良；（2）骨嵴与双管状硬脊膜；（3）脊髓水囊肿；（4）严重脊柱侧弯和异常神经根；（5）终丝及骶等肿瘤，结论 5种病理因素通过先天性缺陷，栓系和压迫机制导致脊髓发生病理变化，影响脊髓功能，应当选择切除骨嵴，硬脊膜成型，终丝切断，囊肿内引流和先天性脊柱侧弯矫形等治疗方法。     

Intraoperative Facial Nerve Monitoring (IFNM) Predicts Facial Nerve Outcome after Resection of Vestibular Schwannoma

Summary Intraoperative facial nerve monitoring (IFNM) is a suitable technique for intraoperative facial nerve identification and dissection, especially in large vestibular schwannomas (VS) (acoustic neuroma). To evaluate its feasibility for estimating functional nerve outcome after VS resection 60 patients underwent surgery using IFNM. Out of this group the last 40 patients were included in a prospective study evaluating the prognostic value of various IFNM parameters (proximal and distal absolute EMG amplitude, stimulation threshold, and proximal-to-distal amplitude ratio) for prediction of initial postoperative facial nerve function and recovery of function. Stimulation threshold and absolute EMG amplitude proximally at the brain stem were both predictive for postoperative nerve function. Good initial facial nerve outcome (modified House Brackmann grading, mHB°I and °II) was found in 15/16 patients with a proximal EMG amplitude greater than 800 μV and in 19/22 patients with proximal stimulation threshold less than 0.3 mA. Sixteen of 16 patients with proximal stimulation threshold equal to or greater than 0.3 mA had moderate-to-severe facial palsy (mHB°III or worse). Six of six patients without evokable proximal amplitude initially had insufficient nerve function (mHB°IV). Intraoperative decrease of the proximal amplitude was associated with an unfavourable outcome, whereas distal amplitudes usually stayed unchanged. Mean distal EMG amplitudes were also found to be decreased with poor nerve function, which may mean that the tumour had already affected the nerve. A proximal amplitude of 300 μV or less and a proximal-to-distal amplitude ratio below 1:3 were found in the absence of functional recovery in 6/8 (75%) and 5/6 (83%) patients with initial mHB°IV, respectively. Two patients with initial mHB°IV improved to mHB°III despite intraoperative evidence of missing functional nerve integrity. Therefore, functional recovery cannot be predicted by IFNM in all cases of anatomical nerve preservation. We conclude that a minimum follow-up period of 1 year may still be advisable even in certain patients without evidence of intraoperative functional nerve integrity.     

Utility of direct stimulation of roots in spinal surgery

Prevention of postoperative neurological deficits is a major concern of spinal surgeons and has led to the introduction and current development of intraoperative neurophysiological monitoring. We have used motor evoked potentials and somatosensory evoked potentials as routine monitoring techniques and, in some cases, added optional methods such as direct stimulation of nerve roots and spinal evoked potentials. We report our experience of direct nerve root stimulation as an optional monitoring method during spinal surgeries in 7 patients with lesions affecting the proximal nerve roots aged from 1 day to 78 years (mean 23.5 years). Four patients had anomalous lesions, two had spinal nerve root schwannomas, and one had a far-lateral lumbar disc herniation. Direct stimulation was used for detection of motor nerve roots in the anomalous lesions and schwannomas, and to distinguish the nerve root from the paraspinal soft tissues in the case of a far-lateral herniated disc at the L5-S1 level. Although some patients had slight transient neurological symptoms such as motor weakness and sensory disturbance, none developed severe permanent neurological impairment. Direct stimulation allows detection of the motor nerve during spinal surgery in real time. Our limited experience suggests that the direct stimulation technique could reduce the risk of motor or vesicorectal disturbance after surgery of lesions affecting or involving the spinal nerve roots.     

Multiple filum terminale hemangioblastomas symptomatic during pregnancy. Case report

Hemangioblastomas are low-grade, highly vascular tumors commonly associated with von Hippel-Lindau (VHL) syndrome and most often appearing in the cerebellum. They very rarely occur in the spinal nerve roots, and an origin in the filum terminale is exceptional with no instances of multiple hemangioblastomas of the filum terminale reported in the literature. Because of their vascular nature, these lesions can enlarge and become symptomatic in the context of the changes that take place during pregnancy, as has been noted with cerebellar hemangioblastomas. In any case, the evolution of spinal hemangioblastomas during pregnancy is not well known given its rarity. The conjunction of both processes--that is, multiple hemangioblastomas arising in the filum terminale and pregnancy--is unique. The authors describe the case of a 41-year-old woman with multiple hemangioblastomas of the filum terminale and no other evidence of VHL syndrome, in whom pregnancy precipitated symptoms. The interruption of gestation led to a remission of the symptoms. The literature concerning filum terminale hemangioblastomas and pregnancy is also reviewed.     

Adult type tethered cord syndrome with chronic attackwise pain in the bilateral feet

The authors report a case of chronic attackwise pain in the bilateral feet for five years due to tethered cord syndrome. Despite extensive examinations, this condition had been overlooked. The patient is a 21-year-old man. He had suffered attackwise pain resembling sticking a thumbtack in the soles of his feet, since he was 16 years old. The pain appeared several times a day and continued for 30 seconds to 30 minutes for 5 years. Physical examination revealed hammer toes and high-arched feet. The fingers and knee joints showed hyperextension. The neurological findings showed weakness of toe extension, hyporeflexia of deep tendon reflexes in the leg. Mild hypesthesia was seen in the bilateral soles. Myelography showed sacral dural ectasia. Magnetic resonance images showed dorsal displacement of the conus medullaris, the filum terminale and the cauda equina. A computed tomographic scan after myelography also showed a dorsally located thick filum terminale (the diameter is 2 mm). Surgery disclosed thick and tight filum terminale directly under the dura mater. Its flexibility was diminished. Abnormal lesions such as lipoma, spinal dysraphysm, diastematomyelia, myelomeningocele were not observed. After the untethering operation, the pain attacks decreased dramatically. The condition of the present case is adult onset tethered cord Group 2 described by Yamada. When unusual pain is manifested, we always have to keep this syndrome in mind.     

Anterior sacral meningocele associated with tethered cord syndrome]

A case of anterior sacral meningocele associated with tethered cord syndrome is reported. A 5-year-old boy was admitted for urinary and fecal incontinence which had persisted since his birth. Abdominal MRI and sacral CT showed a presacral cystic mass communicating with the spinal dural sac through a neck traversing a sacral bony defect and tethered spinal conus. Neurological examination showed that the patient had a neurogenic bladder, atrophy of the legs and anesthesia below the S3 level. Operative finding revealed a thickened filum terminale attached to the wall of the presacral meningocele. Agenesis of the nerve root below the S2 level was identified, and no neural elements entered into the sac. Untethering was performed. Postoperative course was uneventful and the patient is doing well with his neurogenic bladder gradually improving.     

Terminal ventriculostomy as an adjuvant treatment of complex syringomyelia: a case report and review of the literature

Complex syringomyelia is multifactorial, and treatment strategies are highly individualized. In refractory cases, sectioning of the filum terminale, also known as terminal ventriculostomy, has been described as a potential adjuvant treatment to alleviate syrinx progression. A 10-year-old boy with a history of arachnoiditis presented with complex syringomyelia, progressive lower extremity motor weakness, and spasticity. Previously, he had failed spinal cord detethering and direct syrinx shunting. Imaging studies demonstrated a holocord syrinx extending to the level of his conus medullaris and into the filum terminale. The patient underwent an uncomplicated lumbar laminectomy and transection of the filum terminale. Operative pathologic specimens demonstrated a dilated central canal within the filum. Postoperative imaging demonstrated significant reduction in the diameter of the syrinx. At follow-up, the patient’s motor symptoms had improved. Terminal ventriculostomy may be a useful adjuvant in treating caudally placed syringes refractory to other treatments. This procedure carries low neurological risk and involves no hardware implantation. In select cases, terminal ventriculostomy may help preserve neurological function in the face of otherwise progressive syringomyelia.     

Tethered cord syndrome in a 24-year-old woman presenting with urinary retention

We discuss a case of newly diagnosed tethered cord syndrome (TCS) in a 24-year-old woman who presented with dysuria, hematuria, and urinary retention. Physical exam revealed hyperreflexic lower extremity deep tendon reflexes. MRI showed filum terminale terminating in a lipoma, consistent with TCS. We discuss the role of MRI in the workup of adults with bladder dysfunction.