MR IMAGING OF CEREBROSPINAL FLUID FLOW AND SPINAL CORD MOTION IN NEUROLOGIC DISORDERS OF THE SPINE

Effect of mindfulness-based mind-body therapies in patients with non-specific low back pain-A network meta-analysis of randomized controlled trials

Background/objectives

Although mindfulness-based mind-body therapy (MBMBT) is an effective non-surgical treatment for patients with non-specific low back pain (NLBP), the best MBMBT mode of treatment for NLBP patients has not been identified. Therefore, a network meta-analysis (NMA) was conducted to compare the effects of different MBMBTs in the treatment of NLBP patients.

Methods

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched for randomized controlled trials (RCTs) applying MBMBT for the treatment of NLBP patients, with all of the searches ranging from the time of database creation to January 2023. After 2 researchers independently screened the literature, extracted information, and evaluated the risks of biases in the included studies, the data were analyzed by using Stata 16.0 software.

Results

A total of 46 RCTs were included, including 3,886 NLBP patients and 9 MBMBT (Yoga, Ayurvedic Massage, Pilates, Craniosacral Therapy, Meditation, Meditation + Yoga, Qigong, Tai Chi, and Dance). The results of the NMA showed that Craniosacral Therapy [surface under the cumulative ranking (SUCRA): 99.2 and 99.5%] ranked the highest in terms of improving pain and disability, followed by Other Manipulations (SUCRA: 80.6 and 90.8%) and Pilates (SUCRA: 54.5 and 71.2%). In terms of improving physical health, Craniosacral Therapy (SUCRA: 100%) ranked the highest, followed by Pilates (SUCRA: 72.3%) and Meditation (SUCRA: 55.9%). In terms of improving mental health, Craniosacral Therapy (SUCRA: 100%) ranked the highest, followed by Meditation (SUCRA: 70.7%) and Pilates (SUCRA: 63.2%). However, in terms of improving pain, physical health, and mental health, Usual Care (SUCRA: 7.0, 14.2, and 11.8%, respectively) ranked lowest. Moreover, in terms of improving disability, Dance (SUCRA: 11.3%) ranked lowest.

Conclusion

This NMA shows that Craniosacral Therapy may be the most effective MBMBT in treating NLBP patients and deserves to be promoted for clinical use.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, PROSPERO [CRD42023389369].

Magnetic Resonance Imaging-CCCFLS Scoring System: Toward Predicting Clinical Symptoms and C5 Paralysis

STUDY DESIGN

A retrospective study.

OBJECTIVE

To develop a new MRI scoring system to assess patients' clinical characteristics, outcomes and complications.

METHODS

A retrospective 1-year follow-up study of 366 patients with cervical spondylosis from 2017 to 2021. The CCCFLS scores (cervical curvature and balance (CC), spinal cord curvature (SC), spinal cord compression ratio (CR), cerebrospinal fluid space (CFS). Spinal cord and lesion location (SL). Increased Signal Intensity (ISI) were divided into Mild group (0-6), Moderate group (6-12), and Severe group (12-18) for comparison, and the Japanese Orthopaedic Association (JOA) scores, visual analog scale (VAS), numerical rating scale (NRS), Neck Disability Index (NDI) and Nurick scores were evaluated. Correlation and regression analyses were performed between each variable and the total model in relation to clinical symptoms and C5 palsy.

RESULTS

The CCCFLS scoring system was linearly correlated with JOA, NRS, Nurick and NDI scores, with significant differences in JOA scores among patients with different CC, CR, CFS, ISI scores, with a predictive model (R2 = 69.3%), and significant differences in preoperative and final follow-up clinical scores among the 3 groups, with a higher rate of improvement in JOA in the severe group (P < .05), while patients with and without C5 paralysis had significant differences in preoperative SC and SL (P < .05).

CONCLUSIONS

CCCFLS scoring system can be divided into mild (0-6). moderate (6-12), severe (12-18) groups. It can effectively reflect the severity of clinical symptoms, and the improvement rate of JOA is better in the severe group, while the preoperative SC and SL scores are closely related to C5 palsy.

LEVEL OF EVIDENCE

III.

Elucidating the Pivotal Neuroimmunomodulation of Stem Cells in Spinal Cord Injury Repair

Spinal cord injury (SCI) is a distressing incident with abrupt onset of the motor as well as sensory dysfunction, and most often, the injury occurs as result of high-energy or velocity accidents as well as contact sports and falls in the elderly. The key challenges associated with nerve repair are the lack of self-repair as well as neurotrophic factors and primary and secondary neuronal apoptosis, as well as factors that prevent the regeneration of axons locally. Neurons that survive the initial traumatic damage may be lost due to pathogenic activities like neuroinflammation and apoptosis. Implanted stem cells are capable of differentiating into neural cells that replace injured cells as well as offer local neurotrophic factors that aid neuroprotection, immunomodulation, axonal sprouting, axonal regeneration, and remyelination. At the microenvironment of SCI, stem cells are capable of producing growth factors like brain-derived neurotrophic factor and nerve growth factor which triggers neuronal survival as well as axonal regrowth. Although stem cells have proven to be of therapeutic value in SCI, the major disadvantage of some of the cell types is the risk for tumorigenicity due to the contamination of undifferentiated cells prior to transplantation. Local administration of stem cells via either direct cellular injection into the spinal cord parenchyma or intrathecal administration into the subarachnoid space is currently the best transplantation modality for stem cells during SCI.

Micro-CT myelography using contrast-enhanced digital subtraction: feasibility and initial results in healthy rats

PURPOSE

The spinal subarachnoid space (SSAS) is vital for neural performance. Although models of spinal diseases and trauma are used frequently, no methods exist to obtain high-resolution myelograms in rodents. Thereby, our aim was to explore the feasibility of obtaining high-resolution micro-CT myelograms of rats by contrast-enhanced dual-energy (DE) and single-energy (SE) digital subtraction.

METHODS

Micro-CT contrast-enhanced DE and SE imaging protocols were implemented with live adult rats (total of 18 animals). For each protocol, contrast agents based on iodine (Iomeron® 400 and Fenestra® VC) and gold nanoparticles (AuroVist™ 15 nm) were tested. For DE, images at low- and high-energy settings were acquired after contrast injection; for SE, one image was acquired before and the other after contrast injection. Post-processing consisted of region of interest selection, image registration, weighted subtraction, and longitudinal alignment.

RESULTS

High-resolution myelograms were obtained with contrast-enhanced digital subtraction protocols. After qualitative and quantitative (contrast-to-noise ratio) analyses, we found that the SE acquisition protocol with Iomeron® 400 provides the best images. 3D contour renderings allowed visualization of SSAS and identification of some anatomical structures within it.

CONCLUSION

This in vivo study shows the potential of SE contrast-enhanced myelography for imaging SSAS in rat. This approach yields high-resolution 3D images without interference from adjacent anatomical structures, providing an innovative tool for further assessment of studies involving rat SSAS.

Temporal changes of spinal subarachnoid space patency after graded spinal cord injury in rats

INTRODUCTION

Disturbances in spinal subarachnoid space (SSAS) patency after SCI have been reported as an incidental finding, but there is a lack of information on its in vivo extent and time course. For substances and cells carried in the cerebrospinal fluid (CSF) to reach damaged neural tissue and promote reparative processes, CSF must be able to flow freely in SASS.

OBJECTIVE

To characterise the extent and time course of SSAS patency disruption in vivo in a rat model after graded SCI.

MATERIALS AND METHODS

Anaesthetised rats were subjected to mild or severe cord contusion at T9. Estimation of SSAS patency was carried out at 1h and 1, 3, 7, 15, 30 and 90 days postinjury, as well as in naïve rats, by quantifying the passage of superparamagnetic beads injected into the CSF at the cisterna magna and recovered at spinal level L2. CSF volume recovery was measured simultaneously. Data were analysed by the two-way ANOVA test.

RESULTS

Estimation of SSAS patency revealed nearly complete blockage early after contusion that was unevenly restored entering the chronic stages. Volume of CSF recovered was also significantly decreased early after injury compared to naïve rats, but was fully restored by 1 month postinjury. Overall, although modestly different from each other, changes in both parameters were more pronounced after severe rather than mild injuries for each time point examined.

CONCLUSIONS

SCI alters SSAS patency. Its extent is a function primarily of time elapsed after lesion and secondly of injury severity. It is reasonable to expect that disturbances in SASS patency might alter CSF dynamics and impair self-reparative mechanisms and intrathecal therapeutics, making SSAS patency blockage a key target for SCI management.

Increased spinal cord movements in cervical spondylotic myelopathy

BACKGROUND CONTEXT

Magnetic resonance imaging (MRI) is a very useful diagnostic test for cervical spondylotic myelopathy (CSM) because it can identify degenerative changes within the spinal cord (SC), disclose the extent, localization, and the kind of SC compression, and help rule out other SC disorders. However, the relationships between changes in cerebrospinal fluid (CSF) flow, cord motion, the extent and severity of spinal canal stenosis, and the development of CSM symptoms are not well understood.

PURPOSE

To evaluate if changes in the velocity of CSF and SC movements provide additional insight into the pathophysiological mechanisms underlying CSM beyond MRI observations of cord compression.

STUDY DESIGN

Prospective radiologic study of recruited patients.

PATIENT SAMPLE

Thirteen CSM subjects and 15 age and gender matched controls.

OUTCOME MEASURES

Magnetic resonance imaging measures included CSF and SC movement. Cervical cord condition was assessed by the Japanese Orthopaedic Association (JOA) score, compression ratio (CR), and somatosensory evoked potentials (SSEPs) of the tibial and ulnar nerves.

METHODS

Phase-contrast imaging at the level of stenosis for patients and at C5 for controls and T2-weighted images were compared with clinical findings.

RESULTS

Cerebrospinal fluid velocity was significantly reduced in CSM subjects as compared with controls and was related to cord CR. Changes in CSF velocity and cord compression were not correlated with clinical measures (JOA scores, SSEP) or the presence of T2 hyperintensities. Spinal cord movements, that is, cord displacement and velocity in the craniocaudal axis, were increased in CSM patients. Increased SC movements (ie, total cord displacement) both in the controls and CSM subjects were associated with altered spinal conduction as assessed by SSEP.

CONCLUSIONS

This study revealed rather unexpected increased cord movements in the craniocaudal axis in CSM patients that may contribute to myelopathic deteriorations in combination with spinal canal compression. Understanding the relevance of cord movements with respect to supporting the clinical CSM diagnosis or disease monitoring requires further long-term follow-up studies.

The impact of spinal cord nerve roots and denticulate ligaments on cerebrospinal fluid dynamics in the cervical spine

Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (∼6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS.

Pathophysiology of primary spinal syringomyelia

OBJECT

The pathogenesis of syringomyelia in patients with an associated spinal lesion is incompletely understood. The authors hypothesized that in primary spinal syringomyelia, a subarachnoid block effectively shortens the length of the spinal subarachnoid space (SAS), reducing compliance and the ability of the spinal theca to dampen the subarachnoid CSF pressure waves produced by brain expansion during cardiac systole. This creates exaggerated spinal subarachnoid pressure waves during every heartbeat that act on the spinal cord above the block to drive CSF into the spinal cord and create a syrinx. After a syrinx is formed, enlarged subarachnoid pressure waves compress the external surface of the spinal cord, propel the syrinx fluid, and promote syrinx progression.

METHODS

To elucidate the pathophysiology, the authors prospectively studied 36 adult patients with spinal lesions obstructing the spinal SAS. Testing before surgery included clinical examination; evaluation of anatomy on T1-weighted MRI; measurement of lumbar and cervical subarachnoid mean and pulse pressures at rest, during Valsalva maneuver, during jugular compression, and after removal of CSF (CSF compliance measurement); and evaluation with CT myelography. During surgery, pressure measurements from the SAS above the level of the lesion and the lumbar intrathecal space below the lesion were obtained, and cardiac-gated ultrasonography was performed. One week after surgery, CT myelography was repeated. Three months after surgery, clinical examination, T1-weighted MRI, and CSF pressure recordings (cervical and lumbar) were repeated. Clinical examination and MRI studies were repeated annually thereafter. Findings in patients were compared with those obtained in a group of 18 healthy individuals who had already undergone T1-weighted MRI, cine MRI, and cervical and lumbar subarachnoid pressure testing.

RESULTS

In syringomyelia patients compared with healthy volunteers, cervical subarachnoid pulse pressure was increased (2.7 ± 1.2 vs 1.6 ± 0.6 mm Hg, respectively; p = 0.004), pressure transmission to the thecal sac below the block was reduced, and spinal CSF compliance was decreased. Intraoperative ultrasonography confirmed that pulse pressure waves compressed the outer surface of the spinal cord superior to regions of obstruction of the subarachnoid space.

CONCLUSIONS

These findings are consistent with the theory that a spinal subarachnoid block increases spinal subarachnoid pulse pressure above the block, producing a pressure differential across the obstructed segment of the SAS, which results in syrinx formation and progression. These findings are similar to the results of the authors' previous studies that examined the pathophysiology of syringomyelia associated with obstruction of the SAS at the foramen magnum in the Chiari Type I malformation and indicate that a common mechanism, rather than different, separate mechanisms, underlies syrinx formation in these two entities. Clinical trial registration no.: NCT00011245.

Simulating CSF flow dynamics in the normal and the Chiari I subarachnoid space during rest and exertion

BACKGROUND AND PURPOSE

CSF fluid dynamics in healthy subjects and patients with Chiari I have been characterized during rest with phase-contrast MR imaging and CFD. CSF flow velocities and pressures in the nonresting state have not been adequately characterized. We used computer simulations to study CSF dynamics during increased heart rates in the normal and Chiari I subarachnoid space.

MATERIALS AND METHODS

Cyclic CSF flow was simulated for multiple cycles in idealized 3D models of the subarachnoid space for normal and Chiari I malformation subarachnoid spaces, with flow cycles corresponding to 80 or 120 heart beats per minute. Flow velocities and pressures were computed by the Navier-Stokes equations. Synchronous bidirectional flow and flow patterns were displayed in Star-CD and inspected visually. Peak velocities and pressure differences in the 2 models were compared for the 2-cycle frequencies.

RESULTS

Elevating the cycle rate from 80 to 120 cpm increased peak superior-inferior pressure gradients (top-bottom) by just 0.01% in the normal model and 2% in the Chiari model. Corresponding average pressure gradients increased by 92% and 100%, respectively. In addition, in both models, the range of synchronous bidirectional flow velocities increased. Systolic velocities had smaller increases with faster cycling. For each cycle rate, peak and average pressure gradients in the Chiari model were greater than in the normal model by 11%-16%.

CONCLUSIONS

Raising the cycle rate from 80 to 120 cpm increased superior-inferior average pressure gradients and the range of synchronous bidirectional flow velocities in the normal and Chiari I models.

Effect of tonsillar herniation on cyclic CSF flow studied with computational flow analysis

BACKGROUND AND PURPOSE

The Chiari I malformation, characterized by tonsils extending below the foramen magnum, has increased CSF velocities compared with those in healthy subjects. Measuring the effect of tonsillar herniation on CSF flow in humans is confounded by interindividual variation. The goal of this study was to determine the effect of herniated tonsils on flow velocity and pressure dynamics by using 3D computational models.

MATERIALS AND METHODS

A previously described 3D mathematic model of the normal subarachnoid space was modified by extending the tonsils inferiorly. The chamber created was compared with the anatomy of the subarachnoid space. Pressures and velocities were calculated by CFA methods for sinusoidal flow of a Newtonian fluid. Results were displayed as 2D color-coded plots and 3D animations. Pressure gradients and flow velocities were compared with those in the normal model. Velocity distributions were also compared with those in clinical images of CSF flow.

RESULTS

The model represented grossly the subarachnoid space of a patient with Chiari I malformation. Fluid flow patterns in the Chiari model were complex, with jets in some locations and stagnant flow in others. Flow jets, synchronous bidirectional flow, and pressure gradients were greater in the Chiari model than in the normal model. The distribution of flow velocities in the model corresponded well with those observed in clinical images of CSF flow in patients with Chiari I.

CONCLUSIONS

Tonsillar herniation per se increases the pressure gradients and the complexity of flow patterns associated with oscillatory CSF flow.

Standard and cardiac-gated phase-contrast magnetic resonance imaging in the clinical course of patients with Chiari malformation Type I

Object

The causal treatment of Chiari malformation Type I (CM-I) consists of removing the obstruction of CSF flow at the level of the foramen magnum. Cerebrospinal fluid flow can be visualized using dynamic phase-contrast MR imaging. Because there is only a paucity of studies evaluating CSF dynamics in the region of the spinal canal on the basis of preoperative and postoperative measurements, the authors investigated the clinical usefulness of cardiacgated phase-contrast MR imaging in patients with CM-I.

Methods

Ninety patients with CM-I underwent preoperative MR imaging of CSF pulsation. Syringomyelia was present in 59 patients and absent in 31 patients. Phase-contrast MR imaging of the entire CNS was used to investigate 22 patients with CM-I before surgery and after a mean postoperative period of 12 months (median 12 months, range 3–33 months). In addition to the dynamic studies, absolute flow velocities, the extension of the syrinx, and tonsillar descent were also measured.

Results

The changes in pulsation were highly significant in the region of the (enlarged) cistern (p = 0.0005). Maximum and minimum velocities (the pulsation amplitude) increased considerably in the region where the syrinx was largest in diameter. The changes of pulsation in these patients were significant in the subarachnoid space in all spinal segments but not in the syrinx itself and in the central canal.

Conclusions

The demonstration of CSF flow pulsation can contribute to assessments of surgical outcomes. The results presented here, however, raise doubts about current theories on the pathogenesis of syringomyelia.

Differentiation between symptomatic Chiari I malformation and asymptomatic tonsilar ectopia by using cerebrospinal fluid flow imaging: initial estimate of imaging accuracy

PURPOSE

To determine the sensitivity and specificity of cerebrospinal fluid (CSF) flow imaging in distinguishing between patients with symptomatic Chiari I malformation and those with asymptomatic tonsilar ectopia by using a neurosurgeon's overall clinical determination as the reference standard.

MATERIALS AND METHODS

The institutional review board of the University of Wisconsin Hospital and Clinics approved our HIPAA-compliant retrospective study and granted a waiver for informed consent. Seventeen patients (five male, 12 female; aged 4-43 years) with tonsils extending more than 5 mm below the foramen magnum were classified by the neurosurgeon as symptomatic for Chiari I malformation or asymptomatic for tonsilar ectopia. The CSF flow images of the two groups were read independently in blinded fashion by four neuroradiologists. Reader agreement was calculated as percentage of readings in each patient that agreed with the neurosurgeon's classification. Sensitivity and specificity were respectively calculated as the percentage of abnormal readings in symptomatic patients and the percentage of normal readings in asymptomatic patients.

RESULTS

Of 17 patients, nine were classified by the neurosurgeon as symptomatic Chiari I malformation and eight as asymptomatic tonsilar ectopia. Agreement between pairs of readers was 63%-44%. For sagittal and transverse images, reader sensitivity for finding abnormal flow in symptomatic Chiari I malformation patients averaged 76% and specificity for normal flow in patients with asymptomatic tonsilar ectopia averaged 62%. The number of positive readings in the symptomatic patient group was significantly greater than that in the asymptomatic group (P < .02).

CONCLUSION

Readers detected an abnormal CSF flow pattern significantly more often in patients with symptomatic Chiari I malformation than in patients with asymptomatic tonsilar ectopia.

Effects of cord motion on diffusion imaging of the spinal cord

Measurement of diffusion and its dependence on direction has become an important tool for clinical and research studies of the brain. Diffusion imaging of the spinal cord may likewise prove useful as an indicator of tissue damage and axonal integrity; however, it is more challenging to perform diffusion imaging in the cord than in the brain. Here we report a study of the effects of motion on single-shot fast spin echo (FSE) diffusion tensor imaging (DTI) of the spinal cord. Diffusion imaging was performed at four different times in the cardiac cycle both without and with velocity compensation of the diffusion gradients. Uncompensated diffusion images demonstrated substantial signal loss artifacts in the cord that were strongly dependent on the delay after the pulse-oximeter trigger. Quantitative diffusion analysis was also strongly affected by this motion artifact. The use of flow-compensated gradients helped to restore normal signal in the cord, especially at particular trigger delays. Theoretical arguments suggest that improved spatial resolution may help eliminate this signal loss. Even with higher spatial resolution, motion-related signal attenuation may still occur in diffusion imaging of pathologies that alter the motion of the cord. However, this same cord motion may contain diagnostically valuable information when probed using appropriate diffusion imaging approaches.

Visualization of Spinal Cord Motion Associated With the Cardiac Pulse by Tagged Magnetic Resonance Imaging With Particle Image Velocimetry Software

OBJECTIVE

The purpose of this study was to evaluate whether or not tagged magnetic resonance (MR) imaging with particle image velocimetry (PIV) software could reveal spinal cord motion clearly.

METHODS

Six volunteers were enrolled in this study. Tagged MR imaging using fast spoiled gradient-recalled acquisition in the steady state with spatial modulation of the magnetization technique was performed using a 1.5-T MR system.

RESULTS

Sagittal vector maps analyzed by PIV software revealed entire spinal cord motion sequentially during the cardiac cycle. The cervical spinal cord initially moved in a caudal direction and then continually oscillated from a cephalic-to-caudal direction. Each volunteer had a different cycle. In the thoracic spinal area, similar findings were observed, although they were slightly less clear than in the cervical area.

CONCLUSION

Tagged MR imaging combined with PIV software, referred to as tagged MR image velocimetry, revealed spinal cord motion associated with the cardiac pulse, especially in the cervical spine.

The clinical application of non-invasive intracranial blood volume pulse wave monitoring

An ultrasonic method was used to non-invasively measure intracranial blood volume (IBV) pulse waveforms. This technology has previously shown a strong association between invasively recorded ICP pulse waves and non-invasively recorded IBV pulse waves. The objective of the present study was to investigate the diagnostic value of non-invasively measured IBV pulse waves in the cases of different pathologies. A total of 75 patients were examined and these included cases of acute, chronic and stabilized hydrocephalus, spinal cord injury and terminal blood flow. These were compared to a control group of 53 healthy volunteers. The object of comparison was normalized and averaged IBV pulse waves. Pathological IBV pulse waveforms were compared with IBV pulse waveforms of the normal group using sub-wave values, the area under waveform curve and the Euclidean distance calculation. The non-invasively measured IBV pulse waveform is not significantly dependent on acoustic path, gender or age. A detectable change in IBV pulse waveform shape was observed in situations when disturbance in intracranial hydrodynamics was present, e.g. during hypoventilation tests, in cases of terminal blood flow and hydrocephaly, depicting the level of hydrocephalus activity and the patient's compensatory capabilities as well as the effect of treatment.

Acute brainstem dissection of syringomyelia associated with cervical intramedullary neurinoma

Intramedullary tumors and syringomyelia typically present with slowly progressing deficits. More rarely, they are characterized by acute presentation or worsening, at times mimicking other more common etiologies. The acute onset of syringomyelia is most likely attributable to an acute increase in cerebrospinal fluid and epidural venous pressure that results in impulsive fluid movement and, ultimately, in the rupture of the syrinx and dissection into the spinal cord or brainstem. Reported here is a case of acute presentation of a small cervical intramedullary neurinoma due to the upward dissection of its associated syrinx. Critical questions are: (1) how can a small tumor produce a large syrinx? and (2) in the absence of craniospinal interferences, which mechanism underlies the acute expansion of the cavity, resulting in a rapid onset? The authors examined the pathophysiology of syrinx formation and enlargement in intramedullary tumors and reviewed the literature, emphasizing the relationship between spinal cord movements and intramedullary pressure. On the basis of current pathogenetic concepts, the authors concluded that tumor-related syringomyelia might be caused by an association of mechanisms, both from within (obstruction of perivascular spaces; increase in extracellular fluid viscosity due to the tumor itself; intramedullary pressure gradients among different cord levels and between the cord and the subarachnoid space) and from without (the cerebrospinal fluid entering the tissue). All these factors may be amplified, as in the reported case, by a tumor located dorsally at the cervical level. Abnormal postures of the spine, such as a prolonged and excessive flexed neck position, may ultimately contribute to the acute dissection of the syrinx.

The influence of pulse and respiration on spinal cerebrospinal fluid pulsation

RATIONALE AND OBJECTIVES

The aim of the study is to elucidate the location and amount of spinal cerebrospinal fluid pulsations and to differentiate and quantify the cardiac and the respiratory influence.

MATERIALS AND METHODS

An echo planar imaging sequence was applied to 5 different levels of the spinal canal of 7 healthy volunteers. The amount of maximal flow and respiratory signal variation were determined by a time and frequency domain analysis, respectively.

RESULTS

CSF pulsation was high in the anterior cervical and in the thoracolumbar spine. Respiratory influence rose by 19% at C1 and by 28% at T12. The systolic flow was elevated during late expiration and the diastolic upward movement was pronounced by early expiration.

CONCLUSION

The pulsation in the lower spine seems to be related to a second motor of CSF movement because there is a rising respiratory influence and a reappearance of pulsation waves. Physiological spinal CSF pulsation contains a relevant respiratory component.

Management of degenerative changes and stenosis of the lumbar spinal canal secondary to cervical spinal cord injury

We describe the case of a 47-year-old female who sustained a C5/6 fracture with C6 complete spinal cord injury 26 years ago. She presented with increased spasticity of the lower extremities, the abdominal wall and episodes of autonomic dysreflexia. Imaging of the spine revealed post-traumatic kyphosis at the level of the injury and degenerative changes of the lumbar spine with marked facet joint hypertrophy at the level of L4/5 causing severe spinal canal stenosis. Discussants of this case comment on the possible pathophysiological mechanisms causing autonomic dysreflexia, especially the development of degenerative changes, Charcot arthropathy and the role of tethering mechanisms. The diagnostic options and management approaches are also discussed.

Treatment of terminal syringomyelia in association with tethered cord syndrome: clinical outcomes with and without syrinx drainage

Object

Current use of magnetic resonance (MR) imaging has led to increased awareness of the frequency of terminal syringomyelia in patients with tethered cord syndrome. However, that the surgical treatment of terminal syringomyelia is necessary remains unclear.

In this study the authors attempted to assess the clinical impact, if any, brought after syrinx decompression on the clinical outcome of tethered cord syndrome.

Methods

They randomly assigned 30 cases of pediatric tethered cord into two treatment groups: those in whom an untethering procedure was performed (Group I) and those in whom this procedure was combined with syrinx decompression (Group II). The 1-year follow-up clinical results obtained in the two groups, in correlation with MR imaging findings, were compared to evaluate the benefit of added syrinx drainage.

Clinical follow-up evaluation revealed that surgical drainage of the syrinx, when combined with spinal cord untethering, resulted in better outcomes in terms of resolution of sensory deficits (p = 0.036) and bladder dysfunction (p = 0.05). The improvement in clinical outcome correlated with the radiologically documented resolution of the syrinx cavity; however, response rates of symptoms differed for each tethering subgroup.

Conclusions

Preliminary results of this study indicated that terminal syringomyelia should be considered as a comorbidity that contributes to the clinical outcome of patients with tethered cord syndrome. A better clinical outcome is achieved following successful decompression of the syrinx in addition to untethering the spinal cord. These findings emphasize the importance of recognizing, evaluating, and treating this pathological entity.