Dural Space Research Articles

Prospective comparative analysis of three types of decompressive surgery for lumbar central stenosis: conventional, full-endoscopic, and biportal endoscopic laminectomy

Conventional open laminectomy has long been considered one of the important surgical options for lumbar central stenosis owing to its positive outcomes. However, newer approaches have emerged as alternatives, including full-endoscopic and biportal endoscopic laminectomy. Therefore, a comparison of the outcomes that are associated with each of these surgical methods is warranted. This prospective multicenter trial, initiated in February 2019, compared the outcomes of three lumbar central stenosis surgical approaches: open laminectomy (OPEN), uniportal endoscopy (UNIPORT), and biportal endoscopy (BIPORT). Among 115 participants from seven centers, one-year follow-ups assessed laboratory, radiological, and clinical outcomes. Despite all groups showing adequate decompression and clinical improvement, the OPEN group exhibited less improvement in Visual analog scale (VAS) for back pain scores (p < 0.05) and significant postoperative increases in most laboratory markers. Furthermore, the OPEN group experienced a significant decrease in multifidus muscle cross-sectional area compared to endoscopic groups (p < 0.001). Each surgical techniques produced similar clinical outcomes and dural space expansion. However, endoscopic surgery was associated with better muscle preservation and better relief of back pain. Endoscopic surgery is a reasonable alternative to conventional laminectomy for treating lumbar central stenosis.This trial was registered on CRIS (Clinical Research Information Service, KCT0004355).

Deep learning segmentation of peri-sinus structures from structural magnetic resonance imaging: validation and normative ranges across the adult lifespan

BackgroundPeri-sinus structures such as arachnoid granulations (AG) and the parasagittal dural (PSD) space have gained much recent attention as sites of cerebral spinal fluid (CSF) egress and neuroimmune surveillance. Neurofluid circulation dysfunction may manifest as morphological changes in these structures, however, automated quantification of these structures is not possible and rather characterization often requires exogenous contrast agents and manual delineation.MethodsWe propose a deep learning architecture to automatically delineate the peri-sinus space (e.g., PSD and intravenous AG structures) using two cascaded 3D fully convolutional neural networks applied to submillimeter 3D T2-weighted non-contrasted MRI images, which can be routinely acquired on all major MRI scanner vendors. The method was evaluated through comparison with gold-standard manual tracing from a neuroradiologist (n = 80; age range = 11–83 years) and subsequently applied in healthy participants (n = 1,872; age range = 5-100 years), using data from the Human Connectome Project, to provide exemplar metrics across the lifespan. Dice-Sørensen and a generalized linear model was used to assess PSD and AG changes across the human lifespan using quadratic restricted splines, incorporating age and sex as covariates.ResultsFindings demonstrate that the PSD and AG volumes can be segmented using T2-weighted MRI with a Dice-Sørensen coefficient and accuracy of 80.7 and 74.6, respectively. Across the lifespan, we observed that total PSD volume increases with age with a linear interaction of gender and age equal to 0.9 cm3 per year (p < 0.001). Similar trends were observed in the frontal and parietal, but not occipital, PSD. An increase in AG volume was observed in the third to sixth decades of life, with a linear effect of age equal to 0.64 mm3 per year (p < 0.001) for total AG volume and 0.54 mm3 (p < 0.001) for maximum AG volume.ConclusionsA tool that can be applied to quantify PSD and AG volumes from commonly acquired T2-weighted MRI scans is reported and exemplar volumetric ranges of these structures are provided, which should provide an exemplar for studies of neurofluid circulation dysfunction. Software and training data are made freely available online (https://github.com/hettk/spesis).

A childhood secondary headache case associated with Langerhans cell histiocytosis

Neurological involvement is very rare in patients with a diagnosis of Langerhans Cell Histiocytosis (LCH). During the course of the disease, headache can also be seen in addition to systemic effects. A 6 years old girl was admitted to the hospital with only a headache without any systemic symptoms and was diagnosed with LCH. Magnetic resonance imaging showed a solid mass extending from the sphenoid bone corpus to the left great wing of the sphenoid, left orbital apex, left posterior ethmoid cells, left cavernous sinus, and dural space. The correct decision for neuroimaging in patients with headaches is very important in terms of mortality and morbidity. We wanted to share our patient’s case who was diagnosed with LCH by presenting only with headache without any other systemic finding, to remind that LCH may be a secondary cause of headache.

Parasagittal dural space hypertrophy and amyloid-β deposition in Alzheimer's disease.

One of the pathological hallmarks of Alzheimer's and related diseases is the increased accumulation of protein amyloid-β in the brain parenchyma. As such, recent studies have focused on characterizing protein and related clearance pathways involving perivascular flow of neurofluids, but human studies of these pathways are limited owing to limited methods for evaluating neurofluid circulation non-invasively in vivo. Here, we utilize non-invasive MRI methods to explore surrogate measures of CSF production, bulk flow and egress in the context of independent PET measures of amyloid-β accumulation in older adults. Participants (N = 23) were scanned at 3.0 T with 3D T2-weighted turbo spin echo, 2D perfusion-weighted pseudo-continuous arterial spin labelling and phase-contrast angiography to quantify parasagittal dural space volume, choroid plexus perfusion and net CSF flow through the aqueduct of Sylvius, respectively. All participants also underwent dynamic PET imaging with amyloid-β tracer 11C-Pittsburgh Compound B to quantify global cerebral amyloid-β accumulation. Spearman's correlation analyses revealed a significant relationship between global amyloid-β accumulation and parasagittal dural space volume (rho = 0.529, P = 0.010), specifically in the frontal (rho = 0.527, P = 0.010) and parietal (rho = 0.616, P = 0.002) subsegments. No relationships were observed between amyloid-β and choroid plexus perfusion nor net CSF flow. Findings suggest that parasagittal dural space hypertrophy, and its possible role in CSF-mediated clearance, may be closely related to global amyloid-β accumulation. These findings are discussed in the context of our growing understanding of the physiological mechanisms of amyloid-β aggregation and clearance via neurofluids.

Assessment of Meningeal Lymphatics in the Parasagittal Dural Space: A Prospective Feasibility Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD wash-out rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040). This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.

Subdural hematoma expansion in relation to measured mean and peak systolic blood pressure: A retrospective analysis.

Subdural hematomas (SDH) account for an estimated 5 to 25% of intracranial hemorrhages. Acute SDH occur secondary to rupture of the bridging veins leading to blood collecting within the dural space. Risk factors associated with SDH expansion are well documented, however, there are no established guidelines regarding blood pressure goals in the management of acute SDH. This study aims to retrospectively evaluate if uncontrolled blood pressure within the first 24 h of hospitalization in patients with acute SDH is linked to hematoma expansion as determined by serial CT imaging. A single center, retrospective study looked at 1,083 patients with acute SDH, predominantly above age 65. Of these, 469 patients met the inclusion criteria. Blood pressure was measured during the first 24 h of admission along with PT, INR, platelets, blood alcohol level, anticoagulation use and antiplatelet use. Follow-up CT performed within the first 24 h was compared to the initial CT to determine the presence of hematoma expansion. Mean systolic blood pressure (SBP), peak SBP, discharge disposition, length of stay and in hospital mortality were evaluated. We found that patients with mean SBP <140 in the first 24 h of admission had a lower rate of hematoma expansion than those with SBP > 140. Patients with peak SBP > 200 had an increased frequency of hematoma expansion with the largest effect seen in patients with SBP > 220. Other risk factors did not contribute to hematoma expansion. These results suggest that blood pressure is an important factor to consider when treating patients with SDH with medical management. Blood pressure management should be considered in addition to serial neurological exams, repeat radiological imaging, seizure prophylaxis and reversal of anticoagulation.

Improving the diagnosis of radiation necrosis after stereotactic radiosurgery to intracranial metastases with conventional MRI features: a case series

BackgroundThe distinction between true disease progression and radiation necrosis after stereotactic radiosurgery to intracranial metastases is a common, but challenging, clinical scenario. Improvements in systemic therapies are increasing the importance of this distinction. A variety of imaging techniques have been investigated, but the value of any individual technique is limited.Case presentationAssessment should extend beyond simply the appearances of the lesion at a given timepoint, but also consider local anatomy and lesion evolution. Firstly, enlargement of a metastasis is affected by local anatomical boundaries, such as the dural reflections or cerebrospinal fluid spaces. In contrast, the radiation dose administered with stereotactic radiosurgery does not respect these anatomical boundaries and is largely concentric around the treated lesion. Therefore, new, non-contiguous enhancement across such a boundary can be confidently attributed to radiation necrosis. Secondly, the dynamic nature of radiation necrosis may result in a change in lesion shape, with different portions of the lesion simultaneously enlarging and regressing. Regression of part of a lesion indicates radiation necrosis, even if the overall lesion enlarges. This case series describes these two features and provides illustrative clinical examples in which these features allowed a confident diagnosis of radiation necrosis.ConclusionsThe distinction between true disease progression and radiation necrosis should extend beyond just the appearances of the lesion. More nuanced interpretation incorporating a relationship to anatomical boundaries and a change in shape can improve accurate diagnosis of radiation necrosis.

Evaluation of dural channels in the human parasagittal dural space and dura mater

Here, we report the existence of dural channels in the parasagittal dural space and dura mater in humans. Microscopic mapping was performed to observe dural channels and arachnoid granulations in the whole dural tissue of nine individuals, and ultrastructural examinations and 3D micro-CT were used for further identification. The dural channels were concentrated along the parasagittal dural space regardless of the distribution of arachnoid granulations. Microscopically, they varied in size, presenting as distorted round-shaped empty spaces resembling mature fat vacuoles without subcellular structures. We found them to be lacking in the expression of lymphatic and vascular markers. 3D micro-CT revealed Swiss-cheese-like structured empty spaces connected to each other. Our findings show that dural channels are part of the anatomical structure of the parasagittal dural and space and dura mater. Although they are not the meningeal lymphatic vessels themselves, dural channels may serve as a reservoir of cerebrospinal fluid drainage.

Computed tomography myelography technique and spinal morphometry in healthy Yucatan pigs.

Porcine models of spinal cord injury (SCI) have an irreplaceable role in the development of experimental therapies. There is little literature regarding CT myelogram (CTM) techniques in swine and morphometry in miniature swine has not been established. A CT-guided method for performing myelography as well as reference values for spinal morphometry in healthy Yucatan miniature swine is lacking. The goal of this study is to describe a CT-guided method of performing CTM in a porcine model of SCI and to establish spinal morphometric reference values in mature Yucatan pigs. Six healthy, Yucatan sows, 9 months of age, weighing between 39–57.7kg, with no history of spinal disease, spinal injury, or neurologic deficits on physical exam were used in this study. CT myelography was performed in each sow under general anesthesia. CT scout images were used to guide needle placement at the L3-L4 intervertebral site. Once correct needle placement was confirmed using a 1ml test injection, a full dose of iodinated contrast (0.3ml/kg) was injected slowly over a 2-minute time period. Morphometry was performed using area measurements of the spinal cord (SC), vertebral body (VB), dural sac (DS), and vertebral canal (VC) at the mid-body and the intervertebral disc space of each spinal segment. Of the quantitative measurements, the spinal cord surface area had the widest range of values and the greatest coefficient of variance (CV) while those parameters for the vertebral canal had a low CV. Of the morphometric ratios, the DS:VC, had the lowest CV while the spinal cord ratios to DS and VC had the highest (>30). The vertebral canal surface area and the dural space: vertebral canal ratio may serve as reference values in future studies using this animal model.

Parasagittal dural space and cerebrospinal fluid (CSF) flow across the lifespan in healthy adults

BackgroundRecent studies have suggested alternative cerebrospinal fluid (CSF) clearance pathways for brain parenchymal metabolic waste products. One fundamental but relatively under-explored component of these pathways is the anatomic region surrounding the superior sagittal sinus, which has been shown to have relevance to trans-arachnoid molecular passage. This so-called parasagittal dural (PSD) space may play a physiologically significant role as a distal intracranial component of the human glymphatic circuit, yet fundamental gaps persist in our knowledge of how this space changes with normal aging and intracranial bulk fluid transport.MethodsWe re-parameterized MRI methods to assess CSF circulation in humans using high resolution imaging of the PSD space and phase contrast measures of flow through the cerebral aqueduct to test the hypotheses that volumetric measures of PSD space (1) are directly related to CSF flow (mL/s) through the cerebral aqueduct, and (2) increase with age. Multi-modal 3-Tesla MRI was applied in healthy participants (n = 62; age range = 20–83 years) across the adult lifespan whereby phase contrast assessments of CSF flow through the aqueduct were paired with non-contrasted T1-weighted and T2-weighted MRI for PSD volumetry. PSD volume was extracted using a recently validated neural networks algorithm. Non-parametric regression models were applied to evaluate how PSD volume related to tissue volume and age cross-sectionally, and separately how PSD volume related to CSF flow (significance criteria: two-sided p < 0.05).ResultsA significant PSD volume enlargement in relation to normal aging (p < 0.001, Spearman’s-rho = 0.6), CSF volume (p < 0.001, Spearman’s-rho = 0.6) and maximum CSF flow through the aqueduct of Sylvius (anterograde and retrograde, p < 0.001) were observed. The elevation in PSD volume was not significantly related to gray or white matter tissue volumes. Findings are consistent with PSD volume increasing with age and bulk CSF flow.ConclusionsFindings highlight the feasibility of quantifying PSD volume non-invasively in vivo in humans using machine learning and non-contrast MRI. Additionally, findings demonstrate that PSD volume increases with age and relates to CSF volume and bi-directional flow. Values reported should provide useful normative ranges for how PSD volume adjusts with age, which will serve as a necessary pre-requisite for comparisons to persons with neurodegenerative disorders.

Spinal tumors

Spinal tumors are often classified into three anatomical compartments on the basis of their relationship to the dural space and myelon. The most common primary spinal neoplasms are glial tumors (ependymoma, astrocytoma), nerve sheath tumors (schwannoma, neurofibroma) and meningioma. Metastases represent another common tumor entity and can occur in every spinal compartment. Magnetic resonance imaging (MRI) is the most important noninvasive method for spinal tumor imaging.

EPEN-13. PRIMARY EXTRADURAL SACROCOCCYGEAL SUBCUTANEOUS MYXOPAPILAR EPENDYMOMA MISDIAGNOSED AS PILONIDAL CYST IN A 7 YEAR-OLD BOY: A CASE REPORT

BACKGROUNDEpendymomas occur in the brain or spinal cord and rarely as an extraspinal variety at the sacrococcygeal region, separated from the spinal cord. This rare presentation is thought to originate from a group of heterotopic ependymal cells called the coccygeal medullary vestige. There are few reports of this occurrence in children. CLINICAL CASE: A 7-year-old male presented with a history of a soft mass arising in the sacrococcygeal area 3 years earlier, diagnosed as pilonidal cyst at primary level and treated with surgery twice, as this mass recurred the boy was sent to our hospital, a 3rd surgery was performed, all tumoral tissue was removed, no attachment with dural space was founded, pathology revealed myxopapilar ependymoma with positivity for PS100, EMA and Vimentin. After surgery a Follow up MRI of cranium and spine showed absence of disease, no radiotherapy neither chemotherapy was implemented. He has been on surveillance from 3 years now without recurrence.CONCLUSIONThis report highlights the fact that pediatric ependymoma can have an extradural presentation and can be confounded with pilonidal cyst, total resection is needed to control the disease. Potential for recurrence or metastatic disease can continue 20 years from the time of primary tumor, so prolonged surveillance is important.

Aging Is Positively Associated with Peri-Sinus Lymphatic Space Volume: Assessment Using 3T Black-Blood MRI.

Objectives: Aging is a major risk factor for many neurological disorders and is associated with dural lymphatic dysfunction. We sought to evaluate the association of aging with the volume of the peri-sinus lymphatic space using contrast-enhanced 3T T1-weighted black-blood magnetic resonance imaging (MRI). Methods: In this retrospective study, 165 presumed neurologically normal subjects underwent brain MRIs for cancer staging between April and November 2018. The parasagittal peri-sinus lymphatic space was evaluated using contrast-enhanced 3D T1-weighted black-blood MRIs, and volumes were measured with semiautomatic method. We compared the volumes of normalized peri-sinus lymphatic spaces between the elderly (≥65 years, n = 72) and non-elderly (n = 93) groups and performed multivariate logistic regression analyses to assess if aging is independently associated with the volume of normalized peri-sinus lymphatic spaces. Results: The normalized peri-sinus lymphatic space volume was significantly higher in the elderly than in the non-elderly (mean, 3323 ± 758.7 mL vs. 2968.7 ± 764.3 mL, p = 0.047). After adjusting the intracranial volume, age age was the strongest factor independently associated with peri-sinus lymphatic space volume (β coefficient, 28.4 (5.7–51.2), p = 0.015) followed by male sex (β coefficient, 672.4 (113.5–1230.8), p = 0.019). Conclusions: We found that the peri-sinus dural lymphatic space volume was higher in the elderly group than in the non-elderly group, and the increased peri-sinus lymphatic space was independently associated with aging. These findings indicate that the peri-sinus lymphatic space may be related with the aging process and lymphatic system dysfunction as well.

Anatomical Correlates and Subtleties of Surgery for Pituitary Tumors- A Review of Personal Understanding

The authors review the anatomy of the pituitary gland on the basis of cadaver dissection studies and anatomy of dural relationships of pituitary tumors and its extensions on the basis of a 35-year-old experience of surgically treating pituitary tumors. Perfect understanding of anatomical correlates and nuances of pituitary tumor surgery is essential to achieve satisfactory surgical results. The pituitary gland is located in a specially enclosed cavity that is neither intracranial nor extracranial. It is covered strategically by meninges. Pituitary gland has a close relationship with cavernous sinuses and sphenoid air sinus. Pituitary tumors range widely in their size. Whilst microadenomas are generally associated with hormonally active tumors, large and giant sized tumors are usually hormonally non-functional. Surgical issues are unique for all sizes of pituitary tumors. Giant pituitary tumors grow in size, but a majority of them are confined to dural compartmental space. Recently proposed classification schemes have enhanced the understanding of anatomical subtleties and dural relationships of growing and giant pituitary tumors.

Posterior Dural Shifts Following Spinous Process-Splitting Multi-Level Intervertebral Lumbar Laminectomies.

Study DesignRetrospective cohort study.PurposeThe aim of our study is to evaluate the extent of posterior spinal dural shift following spinous process splitting multi-level intervertebral lumbar laminectomies, and determine the relationship between posterior spinal dural shift and preoperative parameters.Overview of LiteratureThere are no existing studies on the posterior spinal dural shift after spinous process-splitting multi-leveled lumbar laminectomies.MethodsWe examined 37 patients who underwent spinous process-splitting laminectomies in at least two intervertebral levels, including at the L5/S level. We defined the distance between the vertebral bodies and the anterior edge of the dural sac in the magnetic resonance images at the L5 vertebral level as the anterior dural space (ADS) and detected the difference (d-ADS) between preoperative ADS (pre-ADS) and postoperative ADS (post-ADS). We assessed the relationship between ADS or d-ADS, and preoperative parameters, including age, sex, lumbar lordosis, focal lordosis (FL), and number of decompression levels.ResultsPost-ADS was significantly greater than pre-ADS (p<0.001). Pre-ADS was significantly correlated with FL (p=0.44, p<0.01) and also with post-ADS (p=0.43, p<0.01). d-ADS was negatively correlated with pre-ADS (p=−0.37, p<0.05). A single regression analysis revealed that the relationship between d-ADS and pre-ADS was described as d-ADS=3.67−0.46×pre-ADS. In one of three patients whose d-ADS was above the range of two standard errors, reoperation was performed because of impingement of the nerve root caused by the excessive posterior dural shift.ConclusionsPosterior dural shifts occur after spinous process-splitting multi-level lumbar laminectomies, including at the L5/S level. FL and pre-ADS are good predictive factors for posterior dural shift. Excessive posterior dural shift may lead to stretching and impingement of nerve roots and thus require attention.

Slow sinusoidal tilt movements demonstrate the contribution to orthostatic tolerance of cerebrospinal fluid movement to and from the spinal dural space.

Standing up elicits a host of cardiovascular changes which all affect the cerebral circulation. Lowered mean arterial blood pressure (ABP) at brain level, change in the cerebral venous outflow path, lowered end‐tidal PCO 2 (PETCO 2), and intracranial pressure (ICP) modify cerebral blood flow (CBF). The question we undertook to answer is whether gravity‐induced blood pressure (BP) changes are compensated in CBF with the same dynamics as are spontaneous or induced ABP changes in a stable position. Twenty‐two healthy subjects (18/4 m/f, 40 ± 8 years) were subjected to 30° and 70° head‐up tilt (HUT) and sinusoidal tilts (SinTilt, 0°↨60° around 30° at 2.5–10 tilts/min). Additionally, at those three tilt levels, they performed paced breathing at 6–15 breaths/min to induce larger than spontaneous cardiovascular oscillations. We measured continuous finger BP and cerebral blood flow velocity (CBFv) in the middle cerebral artery by transcranial Doppler to compute transfer functions (TFs) from ABP‐ to CBFv oscillations. SinTilt induces the largest ABP oscillations at brain level with CBFv gains strikingly lower than for paced breathing or spontaneous variations. This would imply better autoregulation for dynamic gravitational changes. We demonstrate in a mathematical model that this difference is explained by ICP changes due to movement of cerebrospinal fluid (CSF) into and out of the spinal dural sack. Dynamic cerebrovascular autoregulation seems insensitive to how BP oscillations originate if the effect of ICP is factored in. CSF‐movement in‐and‐out of the spinal dural space contributes importantly to orthostatic tolerance by its effect on cerebral perfusion pressure.

Frontal placement of subdural drain for subdural hemorrhage: A single center experience

Placing a drain following evacuation of Chronic Subdural Hemorrhage (CSDH) has beneficial outcome for patients. The placement of the drain’s tip however is debatable as it has different rationale among neurosurgeons. Objective: The objective is to see whether the outcome is satisfactory by putting the tip of the drain at the frontal region of the sub dural space. Methodology: We retrospectively studied all patients who had CSDH underwent surgery in our center between January 2013 to December 2016. A total of 34 patients with CSDH underwent drilling of one burr hole and irrigation of CSDH. Silicone catheter placed in the sub dural space and the tip of the drain in the frontal region. We measured the SDH volume reduction and volume of pneumocranium post operatively as our outcomes of the study. Results: The mean reduction of SDH volume after surgery is 8.11 cc (73%), while the mean volume of pneumocranium post SDH drainage is 1.58 cc with a range of 0 cc to 9 cc. The mean Global Outcome Score is 2.85 and the recurrence, which need re-operation are 2 cases (6%). Conclusion: The retrospective case series shows a good potential outcome based on the reduction of SDH volume after surgery. A proper randomized trial is needed to determine the efficacy of the frontal placement of the subdural catheter for a comparable outcome.

Spinal dorsal dermal spinus tract:Case report and review of the literature

A 5 year old male child was brought with a history of fever headache and intermittent discharge from a sinus in the mid-dorsal area in the back. He had recurrent episodes 0f similar complaints since birth and the symptoms used to subside with antibiotic treatment each time.nbsp On examination he was febrile. There was no neurological abnormality.nbsp Posterior aspect of mid-dorsal spine D7 showed a dimple in the skin with pigmentation and there was minimal active discharge.nbsp USG showed dermal sinus tract with suspected communication with subarachnoid space. CT scan showed dorsal dermal sinus tract with a bifid 7th thoracic vertebra. The spinal dermal sinus tract was excised and the tract disconnected from dural space and dura was repaired. All patients with spinal dorsal dermal sinus tract should undergo aggressive surgical treatment in the form of total excision of the sinus tract and correction of spinal malformation.

How I do it: endoscopic endonasal approach to the inferior third of the clivus.

Nowadays, endoscopic endonasal expanded approach targeting for the clival lower third is well described in literature. Nonetheless, great variations can be found among surgical groups, specially during the earlier stages of this procedure. We present a step by step description of the clival lower third approach until entering the dural space, setting its bony limits. We describe the basipharyngeal flap tailoring as a helpful option for latter reconstruction. The study of cadaveric specimens adds clarifying dissections. The expansion in the coronal plane is providential in most of the intradural lesions of the inferior clivus. Basipharyngeal flap may help seal the surgical defects in this area.

Assessment of the Possibilities of B-Mode Ultrasonography in the Diagnosis of Cervical Intervertebral Discs Hernia in Adolescents

Objective: To improve the efficiency of cervical intervertebral discs hernia by determining the ultrasound biomarkers. Materials and Methods: The study included 38 healthy adolescents with normal intervertebral discs and neurologic status and 21 person with the disc hernia. Ultrasonography (USG) was performed at the level of disks C2-C3, C3-C4, C4-C5, C5-C6, C6-C7, C7-Тh1 in longitudinal and transverse projections. In axial section was performed the sagittal intervertebral disc and spinal canal sizes, the anterior dural space size, the width of spinal nerve canals. Results: In 9 (42,9±10,8% ) cases, the hernia was localized at the level of C5-C6, in 7 (33,3 ±10,3%) - C4-C5, in 2 (9,5±6,4%) - at the level of C2-C3 and C6-C7 C7, in 1 (4,8±4,7%) – at the level of C3-C4 respectively. In 13 (61,9±10,6%) cases the hernia had paramedian, in 5 (23,8±9,3%) cases – median, in 3 (14,3±7,6) cases – posterolateral localization. The paramedian hernia was significantly more frequently recorded than the posterolateral (P&lt;0,05) and median hernia (p &lt;0.001). Conclusions: In adolescents in the cervical spine, paramedian hernia are most commonly found, which are most often localized at the level of both C5-C6 and C4-C5. The greatest narrowing and deformation of the spinal nerve canal is observed by posterolateral and paramedian hernia, dural space – by median hernia respectively.