Mid-thoracic Level Research Articles

Regional distribution of mechanical strain and macrophage-associated lung inflammation after ventilator-induced lung injury: an experimental study

BackgroundAlveolar macrophages activation to the pro-inflammatory phenotype M1 is pivotal in the pathophysiology of Ventilator-Induced Lung Injury (VILI). Increased lung strain is a known determinant of VILI, but a direct correspondence between regional lung strain and macrophagic activation remains unestablished. [68Ga]Ga-DOTA-TATE is a Positron Emission Tomography (PET) radiopharmaceutical with a high affinity for somatostatin receptor subtype 2 (SSTR2), which is overexpressed by pro-inflammatory-activated macrophages. Aim of the study was to determine, in a porcine model of VILI, whether mechanical strain correlates topographically with distribution of activated macrophages detected by [68Ga]Ga-DOTA-TATE uptake.MethodsSeven anesthetized pigs underwent VILI, while three served as control. Lung CT scans were acquired at incremental tidal volumes, simultaneously recording lung mechanics. [68Ga]Ga-DOTA-TATE was administered, followed by dynamic PET scans. Custom MatLab scripts generated voxel-by-voxel gas volume and strain maps from CT slices at para-diaphragmatic (Para-D) and mid-thoracic (Mid-T) levels. Analysis of regional Voxel-associated Normal Strain (VoStrain) and [68Ga]Ga-DOTA-TATE uptake was performed and a measure of the statistical correlation between these two variables was quantified using the linear mutual information (LMI) method.ResultsCompared to controls, the VILI group exhibited statistically significant higher VoStrain and Standardized Uptake Value Ratios (SUVR) both at Para-D and Mid-T levels. Both VoStrain and SUVR increased along the gravitational axis with an increment described by statistically different regression lines between VILI and healthy controls and reaching the peak in the dependent regions of the lung (for strain in VILI vs. control was at Para-D: 760 ± 210 vs. 449 ± 106; at Mid-T level 497 ± 373 vs. 193 ± 160; for SUVR, in VILI vs. control was at Para-D: 2.2 ± 1.3 vs. 1.3 ± 0.1; at Mid-T level 1.3 ± 1.0 vs. 0.6 ± 0.03). LMI in both Para-D and Mid-T was statistically significantly higher in VILI than in controls.ConclusionsIn this porcine model of VILI, we found a topographical correlation between lung strain and [68Ga]Ga-DOTA-TATE uptake at voxel level, suggesting that mechanical alteration and specific activation of inflammatory cells are strongly linked in VILI. This study represents the first voxel-by-voxel examination of this relationship in a multi-modal imaging analysis.

Anatomical Registration of Implanted Sensors Improves Accuracy of Trunk Tilt Estimates with a Networked Neuroprosthesis.

For individuals with spinal cord injuries (SCIs) above the midthoracic level, a common complication is the partial or complete loss of trunk stability in the seated position. Functional neuromuscular stimulation (FNS) can restore seated posture and other motor functions after paralysis by applying small electrical currents to the peripheral motor nerves. In particular, the Networked Neuroprosthesis (NNP) is a fully implanted, modular FNS system that is also capable of capturing information from embedded accelerometers for measuring trunk tilt for feedback control of stimulation. The NNP modules containing the accelerometers are located in the body based on surgical constraints. As such, their exact orientations are generally unknown and cannot be easily assessed. In this study, a method for estimating trunk tilt that employed the Gram-Schmidt method to reorient acceleration signals to the anatomical axes of the body was developed and deployed in individuals with SCI using the implanted NNP system. An anatomically realistic model of a human trunk and five accelerometer sensors was developed to verify the accuracy of the reorientation algorithm. Correlation coefficients and root mean square errors (RMSEs) were calculated to compare target trunk tilt estimates and tilt estimates derived from simulated accelerometer signals under a variety of conditions. Simulated trunk tilt estimates with correlation coefficients above 0.92 and RMSEs below 5° were achieved. The algorithm was then applied to accelerometer signals from implanted sensors installed in three NNP recipients. Error analysis was performed by comparing the correlation coefficients and RMSEs derived from trunk tilt estimates calculated from implanted sensor signals to those calculated via motion capture data, which served as the gold standard. NNP-derived trunk tilt estimates exhibited correlation coefficients between 0.80 and 0.95 and RMSEs below 13° for both pitch and roll in most cases. These findings suggest that the algorithm is effective at estimating trunk tilt with the implanted sensors of the NNP system, which implies that the method may be appropriate for extracting feedback signals for control systems for seated stability with NNP technology for individuals who have reduced control of their trunk due to paralysis.

Localized osteophytic changes in the thoracic vertebra: an osteological and cadaveric study

Vertebral spinal osteophytes remain an urgent problem for clinicians of various specialties due to the fact that they can cause problems with food consumption, breathing, and sometimes cause compression of blood vessels and spinal cord. Clinical presentations encompass pain, often radiating, reduced function, stiffness, tenderness in the joints, limited movement, nerve compression, and bone pressing against tissues. Vertebral osteophytes are frequently observed in cadaveric anatomy and skeletal remains. Many instances go untreated or undetected. Several cross-sectional and prospective studies have been conducted and published concerning the cervical and lumbar spine. The current study was carried out to observe the incidence of osteophytes in the thoracic vertebrae and to document their frequency of distribution and prevalence. To study the frequency of distribution of thoracic osteophytes was reviewed in 25 cadavers (over a period of 5 years) & 188 dry thoracic vertebras (T1-T12) of south Indian population of unknown age & sex at the Department of Anatomy, MVJ MC& RH, Bangalore. The study meticulously enumerates the positions of osteophytes across different thoracic levels, aiming to investigate and understand their recurrence patterns. Incidence was expressed in terms of frequency and percentage. Incidence of osteophytes was documented in 6 cadavers and 33 dry bones which accounts for 24 % and 17.6 % respectively. Out of these, majority of them were recognized on to right side than on left side of the vertebras. The frequency of osteophytes was most commonly seen at mid thoracic level (T4-T8) followed by T9, T10 and T2. The data we received allow us to form an idea not only about the prevalence of vertebral spinal osteophytes in general, but also about the specific features of their location. Knowledge regarding the thoracic osteophytes is further required for detailed study along with dry bones. A comparative analysis of the prevalence of vertebral spinal osteophytes among people of different specialties, different ethnicities and age groups is important in further research, which will complement the obtained results.

Craniocaudal spread and clinical translation for combined erector spinae plane block and retrolaminar block in soft embalmed cadavers: a randomised controlled equivalence study

BackgroundErector spinae plane (ESP) block spread can be unpredictable. We previously improved the spread of ESP injection by addition of retrolaminar (RL) injection. However, it is not clear whether spread at high thoracic levels is similar to spread at midthoracic levels. Our primary objective was to demonstrate that craniocaudal dye spread was equivalent after combined ESP and RL injection using a 19 G Tuohy needle at the third (T3) and sixth (T6) vertebrae in soft embalmed Thiel cadavers. MethodsWe randomised 20 combined ESP and RL injections to the T3 and T6 vertebral levels on both sides of 10 prone Thiel cadavers. A 3–8 MHz transducer was placed in the paramedian sagittal plane and a single anaesthetist injected 10 ml dye onto the transverse process, then 10 ml dye onto the laminae of T3 or T6. Cadavers were dissected 24 h later. ResultsMean (sd) craniocaudal spread of dye after combined ESP + RL injection at T3 and T6 vertebral levels was equivalent: 8.6 (1.8) vs 8.7 (2.3) levels, respectively; difference (90% confidence interval): –0.1 (–1.4 to 1.6), P=0.904. Dye extended uniformly, cranially and caudally, from the point of injection. A 3D prosection created from a Thiel cadaver confirmed that the dorsal ramus emerges from the costotransverse foramen deep to the intertransverse ligament within the retro-superior costotransverse ligament space. Combined ESP and RL block in six patients before mastectomy achieved extensive anterior, lateral, and posterior chest wall paraesthesia over four to six dermatomes. ConclusionsCombined ESP and RL injections showed equivalent and consistent spread at T3 and T6 injection sites. A pilot study confirmed translation to patients.

Unusual Presentation of a Transdural Spinal Cord Herniation

Idiopathic transdural spinal cord herniation (ITSCH) most commonly occurs through a ventral dural defect at the midthoracic levels with a predilection to affect middle-aged females. It can have various presentations, the most common of which are Brown-Sequard syndrome and spastic paraparesis. Due to its rarity in clinical practice, the diagnosis of ITSCH can be challenging to physicians unfamiliar with this entity. We report an unusual presentation of an ITSCH in a 23-year-old female. The diagnosis was made based on the findings of the spinal cord magnetic resonance.

Monitored epidural catheter placement-ultrasound-guided neurostimulation-aided thoracic catheter placement via caudal route for perioperative analgesia in neonatal thoracotomies: A technical feasibility study.

In this case series, we investigated the feasibility of combining ultrasound and neurostimulation for inserting a stimulating epidural catheter in the thoracic epidural space through the caudal route in neonates. Twelve neonates undergoing tracheo-oesophageal fistula repair under general anaesthesia were studied. The catheter was visible on ultrasound as a hyperechoic dot in the epidural space. Inadvertent high placement was identified in two neonates with neurostimulation, in whom the catheter was withdrawn to the thoracic epidural space, and the position was confirmed on ultrasound. A 0.5 ml/kg bolus dose of 0.125% bupivacaine injected through the epidural catheter was imaged in real-time in the epidural space. Block was effective in 10 neonates; two needed an additional local anaesthetic (LA) bolus. To conclude, ultrasound with neurostimulation facilitates accurate positioning of the caudally placed epidural catheter to the mid-thoracic level in neonates.

Physiological characterization of instrumental learning in the spinal cord using the Paw Withdrawal Learning paradigm

Following spinal cord injury (SCI), sensory and motor functions are severely disrupted yet the spinal circuitry below the injury site continues to maintain active and functional neuronal properties (Edgerton, 2004). The spinal cord is endogenously capable of several forms of adaptive plasticity, including functional re-training with exercise, instrumental, and Pavlovian learning. The paw withdrawal learning (PaWL) paradigm represents a simple spinal instrumental learning model (Jindrich 2019). Briefly, in mice whose spinal cords are completely transected (ST) at mid-thoracic (T7-T9) level, the tibialis anterior (TA) muscle is given a sub maximal threshold shock to a hind leg when the leg is extended below a 1mm imposed threshold from a baseline starting position. The contingent group mice learn to maintain the shocked leg, in a flexed position while the experimentally coupled noncontingent group of mice do not acquire the flexed position. To demonstrate the acquisition of the flexed paw hold is mediated through muscle-specific proprioceptive inputs and a time dependent modification of the spinal interneuronal network associated with the TA motor pool, we measured the TA muscle activity using acute EMG during PaWL in both Contingent stim and non-contingent stim groups. To demonstrate that TA specific sensory afferents are critical in PaWL, we blocked the proprioceptive muscle and the cutaneous afferents using Lidocaine. During PaWL, the TA muscle showed significant EMG activity when compared to medial gastrocnemius and vastus lateralis muscles. We detected greater TA muscle activity in the Contingent stim compared to the non-contingent groups. The significant increase in the EMG amplitude in the TA muscle and time-frequency and power relationships in the contingent group, but not the non-contingent group, suggests that the successful learning requires a temporal engagement of the spinal sensorimotor network. CSULA Mini-Grant 2020 and Joseph/Gomez-Pinilla R01NS056413 (Diversity Supplement) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

E032 Deficiency of Adenosine Deaminase 2: a rare diagnosis in a case of suspected vasculitis

Abstract Background/Aims Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive condition first described in 2014 which is characterised by vasculitis, systemic inflammation, immunodeficiency and cytopenias. The vasculitis is difficult to differentiate from polyarteritis nodosa and typically presents with recurrent strokes. It can also affect the skin and present with livedo racemosa. Clinical presentation varies widely; from vasculitic manifestations which tend to present later in life to severe haematological abnormalities such as bone marrow failure which tend to present earlier in life. Treatment with TNF inhibitors reduces the risk of additional strokes and controls inflammation in the presence of vasculitis but is not very effective against bone marrow failure. Methods We present the case of a 44-year-old gentleman who was being investigated for possible vasculitis by the rheumatology team in view of a history of Raynaud’s, 20-year history of recurrent leg ulcers and a previous pontine infarct. He presented acutely to the emergency department with numbness below the midthoracic level, weakness of his lower limbs and hands and urinary retention. His symptoms had progressed over a period of a few hours. On examination power was 4/5 on the MRC power scale for shoulder abduction and elbow flexion, 2/5 for elbow extension, 3/5 for wrist extension and 1/5 for finger extension. Power was 1/5 on his lower limbs. Sensation to pain was reduced with a T6 sensory level. Proprioception and vibration sense were intact. Upper limb reflexes were brisk. Knee jerks and left ankle jerk were difficult to elicit. Plantars were downgoing. Cranial nerves were normal. Results Bloods showed a white cell count of 6.7x109/l, haemoglobin of 96g/l (microcytic), platelets of 243x109/l, creatinine 119μmol/l (baseline 85μmol/l) and CRP of 42.9mg/l. Vitamin B12 was 200ng/l and folate levels were 2.2μg/L. ANA, ANCA, cryoglobulins and hepatitis serology were negative. MRI brain showed a 4mm area of hyper-density in the left pons. MRI whole spine was unremarkable. CSF showed normal protein, white cell count and glucose level. The patient was transferred to a tertiary neurology centre and a diagnosis of anterior spinal cord infarction was made. A nerve biopsy was performed which showed evidence of vasculitis and he was pulsed with methylprednisolone and commenced on high dose oral steroids. Genetic testing showed a pathogenic mutation in the adenosine deaminase 2 gene. He is currently awaiting to commence treatment with TNF inhibitors. Conclusion We conclude that DADA2 is an important differential in a young patient with suspected vasculitis especially in the presence of infarction. Identification of DADA2 allows initiation of treatment with TNF inhibitors which reduces the risk of additional strokes. Disclosure M. Xenophontos: None. J. Gan: None. A.C. Seneviratne: None.

Spinal cord stimulation for freezing of gait in Parkinson's disease and progressive supranuclear palsy: a case series

Background: Freezing of gait (FOG) in Parkinson's disease (PD) and progressive supranuclear palsy (PSP) exert a significant adverse impact on the patients quality of life, the degree of their disability, and the risk of falls. A specific characteristic of FOG is a poor response to medical treatment. According to the data of open-label clinical trials and clinical case series published in the last decade, spinal cord stimulation (SCS) can be considered as one of the methods to improve this type of movement disorders.
 Materials and methods: We present a clinical series of patients with PD and PSP, who underwent implantation of a chronic epidural SCS system at the mid-thoracic level to correct FOG. The efficacy of surgical treatment was assessed at 2 and 5 months with the following scales and questionnaires: part III Unified Parkinson's Disease Rating Scale of Movement Disorder Society (MDS-UPDRS), Freezing of Gait Questionnaire (FOG-Q), Activity-Specific Balance Confidence Scale (ABC), Parkinson's Disease Quality of Life Questionnaire-8 (PDQ-8), Time up and Go Test (TUG), 10 Meter Walk Test. The patients were asked to report possible adverse reactions after the procedure.
 Results: The results of a 5-month follow-up were obtained from 4 patients (2 with PD and 2 with PSP). There were no adverse events associated with SCS. Оnly one patient with PD experienced a decrease in the severity of motor symptoms according to the MDS-UPDRS part III scale. An increase in the speed of 10 meters' walking distance and TUG test performance was observed in 3 patients. All patients reported an improvement in the quality of life (according to the PDQ-8 questionnaire) and confidence in maintaining balance (according to the ABC questionnaire) by month 2 after surgery. However, at month 5, a negative trend was noted again.
 Conclusion: The SCS method was safe in all 4 clinical cases described. There was a positive effect of SCS on the improvement of FOG and postural balance in PD and PSP. However, the duration of the therapeutic effect may vary.

Cement augmentation for treatment of high to mid-thoracic osteoporotic compression fractures, high-viscosity cement percutaneous vertebroplasty versus balloon kyphoplasty

Whilst the majority of the literature suggests that balloon kyphoplasty (BKP) can relieve pain associated with vertebral compression fractures (VCFs), evidence of high-viscosity cement (HVC) vertebroplasty (VP) or low viscosity cement (LVC) BKP for the treatment of VCFs at the levels of high and mid-thoracic vertebrae remains limited. The purpose of this study was to identify the different outcomes between HVC VP and LVC BKP used to repair high (T4–6) and mid (T7–9)-thoracic VCFs. A total of 114 patients with painful collapsed single-level vertebrae at high to mid-thoracic level who had undergone HVC VP or LVC BKP at a single tertiary medical center was reviewed retrospectively. All patients were divided into the HVC VP group (n = 72) and the LVC BKP group (n = 42). Clinical outcomes including demographic data and visual analogue scale (VAS) were compared. Radiographic data were collected preoperatively, postoperatively, and at final follow-up. More volume (ml) of cement injection was seen in the LVC BKP group (4.40 vs. 3.66, p < 0.001). The operation time (minutes) of the HVC VP group was significantly less than that of the LVC BKP group (33.34 vs. 39.05, p = 0.011). Leakage rate of cement was also fewer in the HVC VP group (26/72 vs. 27/42, p = 0.004). Compared with preoperative data, the VAS was improved after surgery in both groups. The LVC BKP group corrected more middle vertebral body height and local kyphosis angle than the HVC VP group. The outcomes of LVC BKP were not superior to that of HVC VP. HVC VP might be a good alternative to LVC BKP in the treatment of osteoporotic VCFs in high to mid-thoracic spine.

Outcomes of SBRT for Symptomatic Benign Tumors of the Spine

<h3>Purpose/Objective(s)</h3> Benign spinal tumors (BSTs) are rare, present across the age spectrum, and may be associated with significant neurologic morbidity. While conservative medical management may be sufficient, many patients experience progression requiring escalated interventions, including surgery. Stereotactic body radiotherapy (SBRT) may be an additional effective management approach for BSTs in the upfront or adjuvant setting. We report our institutional experience of SBRT in management of BSTs. <h3>Materials/Methods</h3> Patients with symptomatic BSTs treated at a single institution with SBRT from 2010-2020 were retrospectively reviewed. Treatment outcomes including symptom and radiographic response were recorded from the electronic health record and presented with descriptive statistics and analyzed by chi-square and univariate logistic regression. <h3>Results</h3> In total, 31 patients with 36 symptomatic BSTs receiving SBRT were identified. Median age at presentation was 57 (IQR: 43-63). Pain was the primary symptom at presentation (92%), followed by paresthesias (28%) and weakness (19%). Histologies were schwannoma (39%), meningioma (33%), hemangioma (22%), and other (6%). Treated spine levels were cervical (44%), thoracic (36%), lumbosacral (19%). 47% of patients had prior surgery at the treated site. Median SBRT prescription dose was 25 Gy (range: 18-40 Gy in 3-5 fractions) treated on consecutive days. Median PTV was 6.0 cc (IQR: 3.5-19.4 cc). Median thecal sac max (0.03 cc) dose was 26.2 Gy (range 0.4-30.2). Interval imaging cadence following treatment was q3-6 months. Median radiographic f/u was 28 months (IQR 9-60). 58% of patients reported durable symptom improvements. 44% of patients experienced acute toxicity from treatment including fatigue, esophagitis, regional pain flare (all grade≤2). One patient developed symptomatic radiation-induced mid-thoracic level myelitis at 6 mo following SBRT with neurologic improvement following protracted (>3 mo) steroid administration with taper. 50% of patients demonstrated radiographic response at last follow-up while 3% showed progression and 47% remained stable. There was no significant association between treatment response or acute/late toxicity and lesion location, dose, or prior surgery. <h3>Conclusion</h3> SBRT for BST, as definitive therapy or for salvage following surgery, was largely effective and safe, with limited high-grade toxicity. Most patients demonstrated symptomatic and/or radiographic response following spine-lesion directed SBRT.

Orta seviye torakal vertebra fraktürlerinde perkütan balon kifoplasti deneyimi

Aim: Balloon kyphoplasty is a popular minimally invasive technique for vertebral fractures. Although vertebral fractures occur mostly in the thoracolumbar region, compression fractures can be seen in the entire vertebral column. The mid-thoracic levels are difficult areas in terms of complications in minimally invasive procedures. Our study aimed to examine the effect of balloon kyphoplasty on vertebral height, kyphosis angle, and cement leaks as a complication in mid-thoracic vertebral fractures.&#x0D; Materials and Methods: Radiological images, patient files, and pathology results of patients who underwent kyphoplasty due to a single or multiple mid-thoracic vertebral fractures between 2017 and 2020 were retrospectively analyzed.&#x0D; Results: A total of 19 patients (9 males and 10 females) and 28 operated vertebrae were included in the study. The mean age of the patients was 58.42±18.79 (23-86) years, and the mean operation time was 40.18±15.01 minutes (17-99). The amount of cement used during the procedures was 3.68±1.13 mL (1.5-7), and postoperative cement leakage was observed in 12 levels (42.9%). Anterior and median vertebral heights and kyphosis angle improved significantly compared to preoperative values (p

The brain of the tree pangolin (Manis tricuspis). X. The spinal cord.

The spinal cord of the tree pangolin is known to be very short compared to the overall length of the body and tail. Here, we provide a description of the tree pangolin spinal cord to determine whether the short length contributes to specific structural, and potentially functional, differences. The short spinal cord of the adult tree pangolin, at around 13 cm, terminates at the midthoracic level. Within this shortened spinal cord, we could identify six regions, which from rostral to caudal include the prebrachial, brachial, interramal, crural, postcrural, and caudal regions, with both the brachial and crural regions showing distinct swellings. The chemoarchitecture of coronal sections through these regions confirmed regional assignation, being most readily delineated by the presence of cholinergic neurons forming the intermediolateral column in the interramal region and the sacral parasympathetic nucleus in the postcrural region. The 10 laminae of Rexed were observed throughout the spinal cord and presented with an anatomical organization similar to that observed in other mammals. Despite the shortened length of the tree pangolin spinal cord, the regional and laminar anatomical organization is very similar to that observed in other mammals. This indicates that the functional aspects of the short tree pangolin spinal cord can be inferred from what is known in other mammals.

P055 Granulomatosis with polyangiitis presenting as compressive cervico-thoracic myelopathy

Abstract Background/Aims Granulomatosis with polyangiitis (GPA), a subgroup of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), is a small vessel vasculitis, characteristically associated with granulomatous inflammation. It demonstrates an increased propensity for pulmonary and renal involvement, in addition to ear, nose and throat disease. Central nervous system involvement is rare. Methods We present the case of a 64-year-old male who presented with a 6-week history of upper back pain and gradual deterioration in his gait, with associated lower limb paraesthesia and leg weakness. Results His background medical history is significant for a right sided mastoidectomy, in addition to recurrent episodes of sinusitis, with nasal crusting. He also had a history of frequent epistaxis requiring cauterisation. Neurological examination was significant for a spastic paraparesis, with MRC grade 3/5 weakness in lower limb flexors bilaterally, bilateral lower limb hypertonia, sustained clonus, hyperreflexia, and extensor plantar responses. Sensory examination revealed a mid-thoracic sensory level. Other systems examination were normal. Routine blood tests revealed normal full blood count, renal and liver indices. Inflammatory markers were elevated: C-reactive protein 43 mg/L (0-5 mg/L) and erythrocyte sedimentation rate 80 mm/hr (0-15 mm/hr). Gadolinium enhanced MRI spine and brain revealed a circumferential enhancing mass-like lesion extending from C5 to T9 with compression of the spinal cord at T2 and T3 levels, with normal brain parenchyma. There was evidence of mild sinusitis in the maxillary sinuses. CT of the thorax, abdomen and pelvis was normal. Urinalysis was normal, as was his urinary protein creatinine ratio, and there was no evidence of red cell casts. ANCA revealed a strongly positive perinuclear pattern (p-ANCA) with a markedly elevated myeloperoxidase (MPO) autoantibody, 117 (0-10 units/mL). Proteinase-3 (PR3) was negative. On identification of spinal cord compromise, the patient underwent urgent neurosurgical evaluation, and surgical exploration. During surgery, direct visualisation revealed the lesion to be solid and mass-like and samples of the tissue excised were sent for pathological analysis. Histopathological studies revealed a dense lymphocytic infiltrate, with fibrinoid necrosis of blood vessel wall consistent with vasculitis. There was no evidence of granuloma formation. A diagnosis of MPO positive GPA causing compressive myelopathy was made. He was commenced on high dose glucocorticoids which were tapered as per PEXIVAS reduced dose regimen. In tandem, he was commenced on pulsed intravenous cyclophosphamide. Within days of treatment initiation his neurological status improved, and he is currently engaging in rehabilitation. At his most recent review he was walking independently with crutches. Conclusion Our case highlights a rare cause of myelopathy but one that should enter the differential diagnosis when assessing a patient presenting with myelopathy, particularly with a mass-like lesion on neuroimaging. It should be treated aggressively and as part of the life-threatening organ involvement algorithm. Disclosure P. Harkins: None. R. Field: None. S. Hutchinson: None. R. Conway: None.

Computed Tomographic Measurement of Thoracic Pedicle in Filipino Patients

Knowledge of the morphometric measurements of Filipino thoracic spine pedicles would help the surgeons in determining the proper size and increase accuracy of pedicle screws placement during surgery to avoid complications. This study aims to measure the outer diameter, chord length and transverse angulation of the thoracic spine pedicles (T1-T12). A retrospective analysis of patients ages 18-85 years who underwent CT scan of the thoracic spine from January to December 2019. A total of 65 patients were included in the study. Pedicle morphology was measured with the following: transverse outer pedicle diameter, pedicle chord length, and transverse pedicle angle. TOPD was narrowest at the level of T4 (4.2 ± 1.0mm) followed by T5 (4.6 ± 1.0mm) and the largest TOPD at the level of T12 (8.7 ± 2.1mm). The largest PCL was at the level T12 (47.7 ± 4.6mm) and the shortest was at T2 (35.6 ± 3.7mm). The mean TPA largest at the level of T1 (35.8 ± 6.1mm) and progressively decreasing and slight increase at the level of T12 (6.3 ± 3.5mm). Men have larger pedicles as compared with women. It is recommended to use 4.5mm pedicle screw however it should be used with extra caution especially at mid thoracic level and among female patients.

Chondroitin sulfate expression around motoneurons changes after complete spinal transection of neonatal rats

Hind limb locomotor activity spontaneously recovers after complete spinal transection (CST) in neonatal rats, but the mechanisms underlying the recovery are poorly understood. The perineuronal net (PNN) surrounding the neuronal cell bodies comprises an extracellular matrix that regulates neuronal plasticity during development. Here, we examined the expression of chondroitin sulfate (CS), a major component of the PNN, on motoneurons after CST in neonatal rats, and compared it with that in juvenile rats, in which hindlimb locomotor activity does not recover spontaneously.The spinal cord was transected at the mid-thoracic level in neonatal (postnatal day 5 [P5] and P10) and juvenile (P15 and P20) rats. Two weeks after CST, the percentage of motoneurons surrounded by chondroitin sulfate C (CS-C) − positive structures was significantly lower in rats with CST at P10 than in intact rats, and tended to be higher in rats with CST at P15 than in intact rats. The percentage of motoneurons with CS-A − positive structures was significantly lower in rats with CST at P15 than in intact rats.These findings suggest that CS-A and CS-C are differentially expressed in the PNNs in rats with CST. The decrease in CS-C − positive PNNs might facilitate the formation of new synaptic contacts to motoneurons, resulting in the recovery of the hindlimb locomotor activity in rats with CST during the neonatal period.

Clinical heterogeneity of low flow spinal arteriovenous fistulas; a case series

BackgroundSpinal AVF (SAVF), a potentially treatable cause of myelopathy, remains a challenging diagnosis. Its rarity and non-specific imaging findings often result in misdiagnosis despite a high index of clinical suspicion. The classically described high T2 signal in the spinal cord or prominent vascular flow voids in the intradural space were not infrequently missed on initial imaging, only to be picked up at follow-up imaging after progression of symptoms. Additionally, small sized fistulas(< 1 mm) and SAVF involving less frequent locations like the craniocervical junction in a patient presenting with paraplegia further complicates the diagnosis. On rare occasions, acute atypical presentation following a surgery adds to the conundrum. Definite diagnosis with spinal angiography, the gold-standard modality requires the expertise of highly skilled interventionists which may otherwise lead to false negative findings. We describe four SAVF patients with unconventional presentations, highlighting less described clinical findings.Case presentationFirst was a 50-year-old man presented with spastic paraparesis and was found to have an AVF at the cervical region arising from the vertebral artery. Second, a 45-year-old man with acute paraplegia post-operatively, initially treated for a transverse myelitis before lumbar region AVF was detected. Thirdly, a 27-year-old man presented with subacute lower thoracic myelopathy and deteriorated after corticosteroid treatment. The last patient, who initially appeared to have conus medullaris/cauda equina syndrome had a SAVF at the mid thoracic level. Presentation varied with some exhibiting acute deterioration mimicking other spinal cord pathology such as inflammatory disorders. All patients eventually underwent endovascular treatment with successful embolization of SDAVF. None of them exhibited further neurological deterioration after embolization.ConclusionSuccessful treatment of SAVF is possible provided the diagnosis is made early, allowing timely intervention. Certain clues may aid the diagnosis. Firstly, arteriovenous fistula can be located distant to the clinical localization of myelopathy resulting in the unexpected longitudinally extensive spinal cord signal change. This clinical-radiological discrepancy can be a useful clue in diagnosing SAVF. Secondly, an acute myelopathic presentation immediately post-surgery may be related to SAVF. Other SAVF feature of note includes progressive myelopathy mimicking immune-mediated myelitis among young adults below 30 years of age refractory to immune therapy.

Ossification and Fusion of the Vertebral Ring Apophysis as an Important Part of Spinal Maturation.

In scoliosis, most of the deformity is in the disc and occurs during the period of rapid growth. The ring apophyses form the insertion of the disc into the vertebral body, they then ossify and fuse to the vertebrae during that same crucial period. Although this must have important implications for the mechanical properties of the spine, relatively little is known of how this process takes place. This study describes the maturation pattern of the ring apophyses in the thoracic and lumbar spine during normal growth. High-resolution CT scans of the spine for indications not related to this study were included. Ossification and fusion of each ring apophysis from T1 to the sacrum was classified on midsagittal and midcoronal images (4 points per ring) by two observers. The ring apophysis maturation (RAM) was compared between different ages, sexes, and spinal levels. The RAM strongly correlated with age (R = 0.892, p < 0.001). Maturation differed in different regions of the spine and between sexes. High thoracic and low lumbar levels fused earlier in both groups, but, around the peak of the growth spurt, in girls the mid-thoracic levels were less mature than in boys, which may have implications for the development of scoliosis.

Magnetic Resonance Imaging Images of the Local Anesthetic Spreading after Erector Spinae Plane Block at T2 Level

It has been reported that erector spinae plane block (ESPB), which was performed at the mid-thoracic level, can be effective for the visceral and somatic pain of the thoracic region. The magnetic resonance imaging (MRI) images showed the diffusion of the contrast medium into the transforaminal and epidural spaces after ESPB, and these MRI findings helped to understand the mechanism of the analgesic effect. There have also been reports that ESPB at the upper thoracic level can reduce the pain of the shoulder and upper extremities. However, no MRI images have been reported to support the mechanism of analgesic effect in the cervical region. We report for the first time the MRI images of local anesthetic spread after ESPB at the T2 level.

Effect of cerebrospinal fluid pressure elevation on spinal cord perfusion during aortic cross-clamping with distal aortic perfusion.

Distal aortic perfusion (DaP) is a widely accepted protective adjunct facilitating early reinstitution of visceral perfusion during extended thoracic and thoraco-abdominal aortic repair. DaP has also been suggested to secure distal inflow to the paraspinal collateral network via the hypogastric arteries and thereby reduce the risk of spinal cord ischaemia. However, an increase in cerebrospinal fluid (CSF) pressure is frequently observed during thoracoabdominal aortic aneurysm repair. The aim of this study was to evaluate the effects of DaP on regional spinal cord blood flow (SCBF) during descending aortic cross-clamping and iatrogenic elevation of cerebrospinal fluid pressure. Eight juvenile pigs underwent central cannulation for cardiopulmonary bypass according to our established experimental protocol followed by aortic cross-clamping of the descending thoracic and abdominal aorta-mimicking sequential aortic clamping-with the initiation of DaP. Thereafter, CSF pressure elevation was induced by the infusion of blood plasma until baseline CSF pressure was tripled. At each time-point, microspheres of different colours were injected allowing for regional SCBF analysis. DaP led to a pronounced hyperperfusion of the distal spinal cord [SCBF up to 480%, standard deviation (SD): 313%, compared to baseline]. However, DaP provided no or only limited additional flow to the upper and middle segments of the spinal cord (C1-Th7: 5% of baseline, SD: 5%; Th8-L2: 24%, SD: 39%), which was compensated by proximal flow only at C1-Th7 level. Furthermore, DaP could not counteract an experimental CSF pressure elevation, which led to a further decrease in regional SCBF most pronounced in the mid-thoracic spinal cord segment. Protective DaP during thoraco-abdominal aortic repair may be associated with inadequate spinal protection particularly at the mid-thoracic spinal cord level ('watershed area') and result in the adverse effect of a potentially dangerous hyperperfusion of the distal spinal cord segments.