Lower Thoracic Level Research Articles

Thoracic canal morphology on preoperative magnetic resonance imaging in spinal cord stimulation patients.

In high-frequency spinal cord stimulation anatomic placement targeting of the T9-10 disc space is based on "empiric" results that are best replicated with coverage broadly from T8 to T10. This study contains the largest cohort of patients evaluating low thoracic morphology and seeks to address the lack of MRI morphological analysis in literature. This study was a retrospective review of a database of 101 consecutive patients undergoing permanent implant of thoracic SCS for chronic pain. Measurements were carried out on preoperative MRI imaging. Anteroposterior (AP) and lateral dimensions of the spinal cord as well as dural sac were measured. In addition, dorsal cerebrospinal fluid thickness and paddle depression distance were also measured. When comparing morphological dimensions by level, dorsal CSF thickness was smaller at T9-10 than T7-8 (p = 0.018). In addition, lateral dural and spinal cord diameters were larger at T10-11 than T9-10, contributing to larger dural surface area at T10-11 (p = 0.028). While trends of dorsal CSF thickness tend to decrease with lower thoracic levels, the ratio of surface area of spinal cord to dural sac appeared to remain relatively constant. Dorsal CSF thickness is smaller at T9-10 than T7-8 in chronic pain patients in this cohort. More ellipsoid, cord, and spinal canal diameter measurements were noted at lower levels of the thoracic spinal cord, particularly at T10-11. This may correlate with anatomical SCS placement. Future studies should evaluate efficacy of SCS therapy for pain based on these anatomical considerations.

Reliability and validity of the T-shirt test for the assessment of unsupported sitting in manual wheelchair users with spinal cord injury.

This study aimed to evaluate the validity and reliability of the T-shirt test (TST) in assessing sitting stability under three thigh support conditions and with timed outcomes derived in six ways among individuals with a spinal cord injury (SCI). The TST was performed five times under three thigh support conditions (85%, 55% and 25% of total thigh length) in two evaluations spaced between 7-14 days. For each thigh condition, six different outcomes were derived (average or best time from 2, 3, and 5 trial). All outcomes derivation showed excellent reliability on test day (intraclass correlation coefficient; ICC ≥ 0.997) and excellent test-retest reliability (ICC ≥ 0.874) for each thigh support condition. The TST showed high inverse correlations with the Spinal Cord Independence Measure III (SCIM)-mobility score for all outcomes and support conditions (ρ≥-0.706), except for Best-5; moderate inverse correlations with total SCIM-total scores for most outcome derivations and support conditions (ρ≥-0.636); and a moderate inverse correlation with confidence and capacity domains of Wheelchair Skills Test-Questionnaire for most outcome derivation and support conditions (ρ≥-0.504). The TST could discriminate cervical from high and low thoracic levels of injuries under minimal thigh support condition. Overall, all the TST-derived outcomes and support conditions showed adequate validity and test-retest reliability, but Best-5 had inconsistency. Under the minimal thigh support condition, all outcome derivations except Best-3 could discriminate cervical from other injury-level groups. Although all outcome derivations and thigh support conditions provided reliable results, we recommend using the average of 3 trials under the maximal thigh support condition.

0707 Spinal Cord Stimulation for Restless Legs Syndrome: Case Report and Scoping Review

Abstract Introduction Restless legs syndrome (RLS) can dramatically impair sleep quality and quality of life. Some patients have insufficient treatment response or intolerance to available pharmacological options. Exploration of novel therapeutic approaches is needed. Methods We report a case of spinal cord stimulation (SCS) providing benefit in RLS. We also performed a scoping review of SCS in RLS with comprehensive literature search of MEDLINE, EMBASE, Cochrane, and Scopus. Results A 77-year-old woman with DM2, OSA (on ASV), depression, familial RLS and iron deficiency with typical RLS symptoms for all of her adult life presented for management in 2000. In 2011 she developed intractable painful peripheral neuropathy and chronic back pain. Levodopa, pramipexole, oral/intravenous iron, gabapentin, pregabalin, tramadol, oxycodone, and methadone were ineffective or poorly tolerated. A 7-day percutaneous SCS trial resulted in RLS symptoms improvement initially by 50%. A Medtronic stimulator with lead placement at T8-T9 was implanted. 6 months later, the patient toggled between a tonic program (2.1-4.6 mA, 200 us, 50 Hz) and a sub-perception, differential target multiplexed program duty-cycled to 1:2 on:off (3.7 mA, 170 us, 300 Hz). She reported 75% improvement in RLS symptoms. Pain improved by 50%. Total daily dose of Oral Morphine Equivalents was reduced from 48.75mg/day to 37.5mg/day, with a stable once daily dose of 400 mg gabapentin at night. Uninterrupted sleep went from 2-5 hours to 6 hours. RLS worsened when the device was off. Our case corroborates the current evidence of benefit of SCS for RLS from the literature. We identified other 16 unique patients from case reports and series who had undergone SCS for RLS. Leads were most often implanted in mid or low thoracic levels. Stimulation waveforms were high frequency in 4 patients, tonic in 3 patients, burst stimulation in 1 patient, and undescribed in the others. All patients had RLS symptom reduction. Comorbid pain was reported in 14 patients, which also improved with SCS. Complication with lead erosion was reported in one case. Conclusion SCS remains a promising therapeutic approach for refractory RLS that deserves further investigation. SCS may reduce hyperexcitability seen in RLS by modulating dysfunctional spinal, subcortical, and cortical networks. Support (if any)

The anatomical variations of the additional communicating rami in the proximal sympathetic trunk: A human cadaveric study

BackgroundIn literature, four types of additional communicating branches of the sympathetic trunk are described. Data concerning location, presence, and variation of these rami are confusing and often incomplete. In this study, incidence of all additional rami of the upper thoracic sympathetic trunk at levels T2 to T5, including the nerve of Kuntz, were investigated, specifically examining a difference between right and left trunk and a possible intergender disparity. Material and methodsMicrodissection of the proximal sympathetic chain was bilaterally performed in twenty fixed cadavers (ten male and ten female bodies). Gender, presence of the additional communicating rami and the nerve of Kuntz were obtained. Data were statistically analysed. ResultsEvery thoracic level had at least one normal ramus. Ascending rami were only observed at level T4 and T5. The lower thoracic levels had fewer descending rami. Intercostal rami were found at level T2 and T5. The mean incidence of the nerve of Kuntz was 0.65 rami per cadaver. This nerve was present bilaterally in 50% of dissected trunks. ConclusionNo statistically significant differences were found between the total amount of additional communicating rami and the nerve of Kuntz on the right compared to the left trunk, and no intergender difference was discovered. Peculiar, the nerve of Kuntz was present bilaterally in half of the dissected cadavers, with a mean incidence of 0.65 rami per cadaver. This study provides insight in the anatomical variation of the additional communicating rami of the proximal sympathetic chain and will have a benefit on thoracic sympathectomy.

High-Frequency Cervical and High Thoracic Spinal Cord Stimulation to Treat Refractory Failed Back Surgery Syndrome in a Patient with Chronic Neck and Low Back Pain: Case Report

BACKGROUND: Failed back surgery syndrome (FBSS) is defined as lumbar spinal pain of unknown origin that persists following surgical intervention or newly presents after spine surgery (1). This pain may originate from surgery, or the surgery may worsen or insufficiently reduce prior pain (1). From 2004 to 2015, the volume of lumbar fusion surgery increased by 62.3% (2). With the frequency of lumbar fusion surgery comes an increased propensity to develop FBSS. The risk of developing FBSS in patients who have undergone lumbar spine surgery is as high as 50% (3). Spinal cord stimulation (SCS) is a well-established, safe, and effective treatment modality for refractory neuropathic pain conditions such as FBSS (4). CASE REPORT: A 47-year-old patient presented to the clinic with a history of cervical radiculopathy status post C4-C7 posterior spinal fusion, lumbar radiculopathy, lumbar spinal stenosis, congenital spondylolisthesis status post L5-S1 anterior lumbar interbody fusion complicated by a malpositioned screw at the L4-L5 level, L4-L5 retrolisthesis, L5-S1 pseudoarthrosis with subsequent T10 to pelvis fusion, which was later extended to T8 after a fall. The patient developed FBSS resulting in debilitating neck and low back pain. Permanent SCS with leads at C7-T3 were placed without complication. The SCS implant resulted in successful treatment of FBSS with an 80% reduction in pain scores, 86% reduction in MME consumption, and an improvement in performance of activities of daily living. CONCLUSION: This case highlights the use of SCS leads placed over the low cervical and high thoracic levels for the treatment of cervical and lumbar back pain. Due to the complex surgical history of the patient, a unique lead implantation location spanning C7-T3 was required. This lead location is significantly cephalad to the typical lead implantation location of T8-L1 for the treatment of chronic lumbar back pain, as the T8-L1 levels are where neurons responsible for back pain are most heavily concentrated (5). This case highlights the effectiveness of SCS therapy implanted at an atypical location for the treatment of FBSS. KEY WORDS: Atypical cervical and thoracic spinal cord stimulation, case report, chronic refractory neck and low back pain, failed back surgery syndrome, neuromodulation

Deep learning-based reconstruction for 3-dimensional heavily T2-weighted fat-saturated magnetic resonance (MR) myelography in epidural fluid detection: image quality and diagnostic performance.

Heavily T2-weighted fat-saturated (HT2W-FS) magnetic resonance myelography (MRM) is useful for diagnosing the cause of intracranial hypotension. Recently, deep learning-based reconstruction (DLR) has been utilized to improve image signal-to-noise ratios and sharpness while reducing artifacts, all without lengthening acquisition times. This study aimed to compare the diagnostic performance and image quality of conventional reconstruction (CR) and DLR of 3-dimensional (3D) HT2W-FS MRM applied to detecting epidural fluid in patients with clinically suspected intracranial hypotension. This retrospective study included 21 magnetic resonance myelography examinations using both CR and DLR in 21 patients who experienced orthostatic headache between April 2021 and September 2022. Quantitative image quality evaluation was performed by comparing signal-to-noise ratios at the lower thoracic levels. The image quality and artifacts were graded by three readers. The presence of epidural fluid was reported with a confidence score by two readers, and the area under the receiver operating curve, interobserver agreement, and inter-image-set agreement were evaluated. The conspicuity of the dura mater where the epidural fluid was detected was also investigated. Quantitative and subjective image quality, and artifacts significantly improved with DLR (all P<0.001). Diagnostic performance of DLR was higher for both readers [reader 1: area under the curve (AUC) of CR =0.929; 95% confidence interval (CI): 0.902-0.950, AUC of DLR =0.965 (95% CI: 0.944-0.979), P=0.007; reader 2: AUC of CR =0.834 (95% CI: 0.798-0.866), AUC of DLR =0.877 (0.844-0.905), P=0.040]. Correlation with standard care of MRM in CR and DLR were both strong in reader 1 (rho =0.868-0.919, P<0.001), but was respectively strong and moderate in reader 2 (rho =0.734-0.805, P<0.001). Interobserver agreement was substantial (κ=0.708-0.762). The inter-image-set agreement was almost perfect for reader 1 (κ=0.907) and was substantial for reader 2 (κ=0.750). Dura mater conspicuity significantly improved with DLR (P<0.014, reader 1; P<0.001, readers 2 and 3). HT2W-FS magnetic resonance myelography with DLR demonstrates substantial improvements in image quality and may improve confidence in detecting epidural fluid.

Surgical treatment of facial blushing: Patient selection and operative technique (retrospective observational study).

Surgeons are often reluctant to offer further intervention to patients with medically intractable facial blushing. This is mainly because of the relatively high failure rate of blushing resolution and a high incidence of compensatory hyperhidrosis. In this study, we sought to identify the type of blushing that would benefit from surgery and minimize compensatory hyperhidrosis by applying diffuse sympathicotomy (DS).This study was a retrospective review of 62 patients who underwent R2 endoscopic thoracic sympathicotomy (ETS) and preemptive DS for facial blushing. Facial blushing was classified as autonomic-mediated blushing (thermoregulatory, emotional) and vasodilator-mediated blushing (constant) based on the history and precipitating factors for blushing. DS was performed at lower-thoracic levels in the form of limited DS (right R5/7/9/11, left R5/6/8/10) or extended DS (bilateral R5-11).Resolution of blushing (described as “almost disappeared”) was achieved in 48% of patients with a median follow-up of 19.6 months. There was a significant difference in resolution among 3 types of blushing (emotional: 55%, thermoregulatory: 28%, constant: 15%, P = .03). Multivariate analysis confirmed thermoregulatory and constant type blushing as a potential independent predictor of blushing resolution. Even though there was no difference between the DS procedures with respect to compensatory hyperhidrosis, intolerable compensatory hyperhidrosis (Hyperhidrosis Disease Severity Scale = 4) occurred in only 11% of patients. DS redistributed sweating area, being predominantly on the chest and mid-back (89%), also seen on the abdomen-waist-groin-buttocks-thighs (63%). Overall, 77% of patients experienced satisfactory results.Emotional blushing proved to be an established indication of ETS where good long-term results can be expected. Expansion of surgical indication to thermoregulatory or constant type blushing needs to be validated in future studies. Additionally, compensatory hyperhidrosis, another hurdle for ETS, can be minimized by preemptive DS, resulting in redistribution and decrease of sweating.

Correction: Model of excision of the lateral half of the spinal cord at the lower thoracic level for the needs of reconstructive neurosurgery and neurotransplantation

Corrections to the article: https://doi.org/10.25305/unj.234154 In the article by V.V. Medvedev et al., published in UNJ № 3 in 2021, the source number 92 from the reference list does not support the statement given in the appropriate place in the text. Instead, we offer the reader two other works that mention the presence of posterior median spinal artery in the adult rat - D. Mazensky et al. (2017) and O.U. Scremin (G. Paxinos, ed.; 2015, p. 1003, 1005). In most works on this topic (Z. Zhang et al., 2001; Y. Cao et al., 2015; P. Li et al., 2020) the dorsal median vein is considered as the median vessel of the posterior surface of the rat spinal cord, and as in humans, describe 2 parallel dorsal spinal arteries. At the same time, D. Mazensky et al. (2017), sharing the opinion of O.U. Scremin (2015), mention 3 dorsal spinal arteries of the rat, in particular the median one. Taking into account that, from our experience, damage to the median vessel of the posterior surface of the spinal cord is accompanied by its rapid edema and irrepversible deep deficit in the motor function of both hind limbs of the animal, we consider it necessary to draw the reader's attention to this feature of the anatomy of the spinal arteries of an adult rat. Medvediev VV, Abdallah IM, Draguntsova NG, Savosko SI, Vaslovych VV, Tsymbaliuk VI, Voitenko NV. [Model of spinal cord lateral hemi-excision at the lower thoracic level for the tasks of reconstructive and experimental neurosurgery]. Ukr Neurosurg J [Internet]. 2021 Sep 27 [cited 2021 Oct 11];27(3):33-5. Available from: http://theunj.org/article/view/234154 Cao Y, Wu T, Yuan Z, Li D, Ni S, Hu J, Lu H. Three-dimensional imaging of microvasculature in the rat spinal cord following injury. Sci Rep. 2015 Jul 29;5:12643. doi: 10.1038/srep12643. PMID: 26220842; PMCID: PMC4518284. Li P, Xu Y, Cao Y, Wu T. 3D Digital Anatomic Angioarchitecture of the Rat Spinal Cord: A Synchrotron Radiation Micro-CT Study. Front Neuroanat. 2020 Jul 22;14:41. doi: 10.3389/fnana.2020.00041. PMID: 32792915; PMCID: PMC7387706. Mazensky D, Flesarova S, Sulla I. Arterial Blood Supply to the Spinal Cord in Animal Models of Spinal Cord Injury. A Review. Anat Rec (Hoboken). 2017 Dec;300(12):2091-2106. doi: 10.1002/ar.23694. Epub 2017 Oct 13. PMID: 28972696. Paxinos G, editor. The rat nervous system. 4th ed., London: Elsevier; 2015. Scremin OU. Capter 31, Cerebral Vascular System; p. 985‒1011. Zhang Z, Nonaka H, Nagayama T, Hatori T, Ihara F, Zhang L, Akima M. Circulatory disturbance of rat spinal cord induced by occluding ligation of the dorsal spinal vein. Acta Neuropathol. 2001 Oct;102(4):335-8. doi: 10.1007/s004010100377. PMID: 11603808.

Long Cervicothoracolumbal Rigid Bracing Stabilization on Incomplete Spinal Cord Injury of Post-Operated Multi-Focal Upper Cervical-Thoracic Spinal Tuberculosis: A Unique Case Report

Background and aim: Spinal tuberculosis (STB) is a hazardous type of bone tuberculosis that could affect the entire spine, with predilection towards the lower thoracic level. Upper cervical spondylitis occurred only at 0.3 – 1% of all STB cases, but this rare type leads to severe consequences, including tetraplegia, autonomic dysfunction, and respiratory impairment. This case reported long CTLSO rigid external stabilisation reasoning to boost protection whilst recovering tuberculosis despite stable internal stabilisation. Methods: A 34-year-old male came with one year of worsening low-back pain, unintentional weight loss, and gradual loss of power and sensation of both feet within a month. Physical examination showed kyphotic deformity, tenderness, key-muscle-strength 3, and sensory impairment for lower extremities, with no autonomic disturbances. Laboratory works showed chronic ongoing infection. Whole-spine MRI showed multiple spondylodiscitis with multi-focal paravertebral abscesses at C3 – C5, C7 – T3, T9 – T12, L1, severe canal stenosis and anterior segment destruction of T12. Results: The patient was diagnosed with SCI AIS D with a neurological level of L3 secondary to T12 vertebra destruction from STB. He underwent abscess evacuation, debridement, and posterior stabilisation at T10 – L3 and debridement of abscess at C3 – C5 without the need for stabilisation. After procedures, the spine was further stabilised by a CTSLO brace with flexion, extension, lateral flexion, rotation stop. Inward rehabilitation includes incremental mobilisation, upper-limb-extensor-group-strengthening-programme, balance-exercise with ambulation training. Patient discharged with status: ambulate independently with a walker. To date, the patient has returned to work with independent ambulation. Conclusion: Type-III STB was indicated for surgical procedures. Instability of upper cervical prevented patient to performed loadbearing activity thus lowering patient functional outcomes. CTLSO supplementation was given to compensate for 3 lesion sites, the upper cervical, mid-thoracic, and lower-thoracic. For the C3 – C5 lesion, there was no internal stabilisation, so a proper external mode of stabilisation should be given. However, for the thoracic level, CTLSO was given due to (1) incomplete SCI lesion in the absence of deteriorating neurological deficit,c(2) porous nature of STB, and (3) good prognostic recovery of STB with anti-TB medication leading to the reversible neurological deficit.

Anatomical variations of the upper thoracic sympathetic chain: a review.

The objective of this study is to provide a thorough overview of the anatomical variations of the upper thoracic sympathetic trunk to improve clinical results of upper thoracic sympathectomy. In addition, this study strives for standardization of future studies regarding the anatomy of the upper thoracic sympathetic chain. The Web of Science, PubMed and Google Scholar databases were searched using keywords, alone or combined, regarding the anatomy of the thoracic sympathetic chain. The search was limited to studies performed in humans. Fifteen studies were finally included. Cervicothoracic ganglion and nerve of Kuntz were present in 77% and 53%, respectively. The upper thoracic ganglia were predominantly located in their corresponding intercostal space with a relatively downwards shift at the lower thoracic levels. The right sympathetic trunk is prone to have more communicating rami then the left. The lower levels of ganglia tend to have more normal rami. No clear pattern was found concerning the presence of the ascending rami and there was a decrease in the number of descending rami as the chain runs caudally. The intercostal rami remain a rare anatomical variation. This study presents an overview of the anatomy of the upper thoracic sympathetic chain. Its results may guide upper thoracic sympathectomy to improve clinical results. This review also provides a baseline for future studies on anatomical variations of the thoracic sympathetic trunk. More uniform reporting is necessary to compare different anatomical studies.

Transpedicular or Transthoracic Approach: An Outcome Comparison Study on Patients with Neurological Manifestation

Background: Approach to lower-thoracic spine for discectomy remains controversial. In this study, we compare primary and secondary outcomes of transpedicular (TP) and transthoracic (TT) approach for discectomy at lower thoracic levels in patients with neurological manifestations. Methods: In this retrospective study, 12 patients with TP or TT approach for lower thoracic discectomy with neurological manifestation, mainly foot drop, were included. During TP approach, cord manipulation was kept at minimum. Posterior fusion was performed in all patients. TT approach was performed by intended level thoracotomy, anterio-lateral fusion was achieved in this group. The postoperative primary and secondary outcomes of the approach were compared in these patients. SPSS software version 20 was used for analysis, and a P-value &lt; 0.005 was considered significant. Results: Twelve patients with neurological manifestation were operated using either of the approaches. Six patients in TP group and four in TT group attained complete neurological recovery after 10.2 and 7.6 weeks, respectively. The mean operative time was 50% more in TT approach. Blood loss in TP approach was less than half, and patients were mobilized earlier with decreased hospital stay. All patients with TT approach needed postoperative intensive care unit (ICU) admission, two of them developed pulmonary complications and postsurgical intercostal neuralgia, and one had cerebrospinal fluid (CSF) leak and readmission within 30 days of discharge. Conclusions: Although TT approach offers excellent exposure for discs in lower thoracic levels, it is associated with increased morbidity and higher complication rates. On the other hand, TP approach offers ample exposure with reduced operative time and blood loss, as well as early mobilization and discharge.

English

BACKGROUND Erector spinae block is a paraspinal, fascial block that targets the ventral, dorsal rami and rami communications of spinal nerves. The present study was conducted to know the efficacy of ultrasound guided erector spinae block (ESP) block in preoperative analgesia among patients with percutaneous nephrolithotomy (PCNL) attending a tertiary care hospital. METHODS The study was carried out on 596 patients from Jan 2015 to Jan 2020 who were indicated for PCNL. They were divided into two groups, group A (ESP = 373) and group B (intravenous-IV analgesia = 273). In the group A (N = 373), after induction of general anaesthesia, ESP block with 0.5 % bupivacaine and 1 / 200,000 epinephrine (single shot) was given at lower thoracic level (T10 - 12) and IV analgesia was given in group B. All patients were monitored for supplemental opioid requirement intraoperatively as assessed by their haemodynamic status (baseline change in heart rate-HR &amp; mean arterial blood pressure-MAP). The primary outcome of the study was consumption of tramadol in 24 hrs. Pain assessment every 2-hour pre- and post-operatively using numerical rating (NR) scale was considered as the secondary outcome. Categorical outcomes were compared between study groups using chi-square test / Fisher's exact test; Pvalue of &lt; 0.05 was considered statistically significant using IBM SPSS. RESULTS Most of them in group A were free of pain for 24 hours postoperatively with numerical rating scale score of &lt; 3 and did not require any postop rescue analgesics. Only 1 patient showed numerical rating scale score of 4 around 16 hrs. after the surgery and was given tramadol. Supplemental opioid analgesic was not required by any of the patients during the entire intraoperative period. CONCLUSIONS ESP block is a favourable technique that results in very good analgesic effect preoperatively and also lessens the use of intravenous opioids and other analgesics. KEYWORDS ESP Block, PCNL Surgery, Tramadol, Kidney Stones

Simultaneous bidirectional hindlimb locomotion in decerebrate cats

We show that epidural spinal cord stimulation can elicit stable bidirectional locomotion of decerebrate cats on a split-belt treadmill. The stepping pattern of one limb was similar to unidirectional forward walking and, the other—was similar to unidirectional backward walking. This confirms that spinal and brainstem circuitry are sufficient to control such complex and extraordinary motor tasks driven by somatosensory input. Interlimb coordination during forward and backward walking was preserved in 2 out of 4 animals during ‘extreme’ conditions when one of the treadmill belts was stopped. Bidirectional locomotion worsened but was still possible after temporary spinalization by cooling the spinal cord on a low thoracic level. These present evidence for the great degree of the automatism for this stepping mode defined by the spinal neuronal networks.

Motor, sensitive, and vegetative recovery in rats with compressive spinal-cord injury after combined treatment with erythropoietin and whole-body vibration.

Physical therapy with whole body vibration (WBV) following compressive spinal cord injury (SCI) in rats restores density of perisomatic synapses, improves body weight support and leads to a better bladder function. The purpose of the study was to determine whether the combined treatment with WBV plus erythropoietin (EPO) would further improve motor, sensory and vegetative functions after SCI in rats. Severe compressive SCI at low thoracic level was followed by a single i.p. injection of 2,5μg (250 IU) human recombinant EPO. Physical therapy with WBV started on 14th day after injury and continued over a 12-week post injury period. Locomotor recovery, sensitivity tests and urinary bladder scores were analysed at 1, 3, 6, 9, and 12 weeks after SCI. The closing morphological measurements included lesion volume and numbers of axons in the preserved perilesional neural tissue bridges (PNTB). Assessment of motor performance sensitivity and bladder function revealed no significant effects of EPO when compared to the control treatments. EPO treatment neither reduced the lesion volume, nor increased the number of axons in PNTB. The combination of WBV + EPO exerts no positive effects on hind limbs motor performance and bladder function after compressive SCI in rats.

Differences in clinical and radiological features of thoracic disc herniation presenting with acute progressive myelopathy.

Symptomatic thoracic disc herniation (TDH) is relatively rare, but patients with progressive myelopathy require surgical treatment without delay in diagnosis. The aim of this study was to review clinical and radiological features in patients with TDH presenting with myelopathy. A total of 28 consecutive patients with thoracic myelopathy (Frankel grade C or worse) due to TDH who underwent surgery were divided into 3 groups based on the time for development of myelopathy (acute (< 72h), subacute (within a few weeks), and chronic [gradually over > 1month)] and their data were analyzed. The patients in the acute group were significantly younger and had a higher body mass index (BMI) compared to those in the subacute and chronic groups. Most cases of acute myelopathy were affected in the upper thoracic level, whereas all patients with subacute and chronic myelopathy had lesions in the lower thoracic level below T8-9. Interestingly, the affected thoracic level in patients with acute myelopathy matched the upper line of the sternum. The rate of acquired walking ability without assistance was only 50.0% in the acute group. This study suggests that TDH presenting with acute myelopathy may have different clinical and radiological features compared to those of TDH with subacute and chronic myelopathy. Upper TDH should be suspected in cases of acute myelopathy that develops with sudden-onset back pain after certain triggers in younger and higher BMI people. These affected thoracic level matched with the upper line of the sternum in each case.

Physiological fluorodeoxyglucose uptake of spinal cord in adults

Physiological fluorodeoxyglucose (FDG) uptake of spinal cord needs to be correctly recognized during evaluation of whole-body PET scans, especially for oncological cases. Our aim was to analyze physiological cord FDG uptake and its relation to gender, age, body weight, environmental temperature and time to imaging. PET scans of 254 patients in a single year, one patient for every working day were retrospectively selected. Temperature data were obtained from meteorology recordings. Maximum standard uptake value (SUVmax) of spinal cord at cervical and lower thoracic levels were noted. Spinal canal at L5 level, cerebellum and liver were used for normalization. Correlations with age, body weight, time to imaging and environmental temperature were analyzed. Cervical SUV was higher than thoracic SUV (2.5-2.3). Cervical and lower thoracic SUV's were strongly correlated, highest when corrected with L5 level vertebral canal and liver (corr coeff 0.84 and 0.75) and lowest with cerebellum (corr coeff 0.4). Cervical spinal cord FDG uptake was higher for females than males (2.6 to 2.4). Temperature and age did not change spinal cord uptake. There were weak positive correlations with body weight (corr coeff 0.16 and 0.28, cervical and thoracic). There was weak negative correlation of cervical uptake with time to imaging (corr coeff -0.17). Spinal cord FDG uptake at cervical and lower thoracic levels are strongly correlated. Females have slightly higher cervical SUV. Age and temperature does not change spinal cord FDG uptake in adults. Cord SUV's slightly increased with body weight.

Contribution of 5-HT2 Receptors to the Control of the Spinal Locomotor System in Intact Rats.

Applying serotonergic (5-HT) agonists or grafting of fetal serotonergic cells into the spinal cord improves locomotion after spinal cord injury. Little is known about the role of 5-HT receptors in the control of voluntary locomotion, so we administered inverse agonists of 5-HT2 (Cyproheptadine; Cypr), 5-HT2A neutral antagonist (Volinanserin; Volin), 5-HT2C neutral antagonist (SB 242084), and 5-HT2B/2C inverse agonist (SB 206553) receptors intrathecally in intact rats and monitored their effects on unrestrained locomotion. An intrathecal cannula was introduced at the low thoracic level and pushed caudally until the tip reached the L2/L3 or L5/L6 spinal segments. Locomotor performance was evaluated using EMG activity of hindlimb muscles during locomotion on a 2 m long runway. Motoneuron excitability was estimated using EMG recordings during dorsi- and plantar flexion at the ankle. Locomotion was dramatically impaired after the blockage of 5-HT2A receptors. The effect of Cypr was more pronounced than that of Volin since in the L5/L6 rats Cypr (but not Volin) induced significant alteration of the strength of interlimb coordination followed by total paralysis. These agents significantly decreased locomotor EMG amplitude and abolished or substantially decreased stretch reflexes. Blocking 5-HT2B/2C receptors had no effect either on locomotion or reflexes. We suggest that in intact rats serotonin controls timing and amplitude of muscle activity by acting on 5-HT2A receptors on both CPG interneurons and motoneurons, while 5-HT2B/2C receptors are not involved in control of the locomotor pattern in lumbar spinal cord.

Risk of New Fractures in Vertebroplasty for Multiple Myeloma. A Retrospective Study.

Vertebroplasty is a percutaneous minimally invasive procedure indicated for vertebral collapse pain treatment. Among the known complications of the procedure is the augmented risk of new vertebral fractures. There are no specific studies in this patient population describing the risk of new vertebral fractures after vertebroplasty. This study analyzed risk factors associated with new vertebral fractures after vertebroplasty in patients with multiple myeloma. Observational retrospective study in patients with multiple myeloma. The data collection took place from January 1, 2010, to December 30, 2017, at the National Cancer Institute. Clinical data and procedural variables such as cement volume, cement leaks, fracture level, number of treated vertebrae, pedicular disease, and cement distribution pattern, with two years follow-up, were analyzed with the Wilcoxon test, and a logistic regression model was used to identify risk factors related to new vertebral fractures. A confidence interval of 95% was used for analysis. At one-year follow-up, 30% of fractures were reported after vertebroplasty, most of them at low thoracic and lumbar level (50% adjacent level). Vertebroplasty was most commonly performed at the thoracolumbar and lumbar area. We demonstrated a 70.7% median numerical rating scale reduction at one-year follow-up; a significant decrease in opioid consumption occurred only during the first month. Pedicle involvement, disc leakage, cement volume, thoracolumbar and lumbar level, and number of treated vertebrae by intervention are important risk factors when performing vertebroplasty. Prospective randomized studies are needed to evaluate these factors in this specific population.

Recovery of locomotion in cats after severe contusion of the low thoracic spinal cord.

Large bilateral contusions of the T10 thoracic spinal cord were performed in 16 adult cats using a calibrated impactor. EMG and video recordings allowed weekly assessments of key locomotor parameters during treadmill training for 5 wk. Thirty-five days postcontusion, several hindlimb locomotor parameters were very similar to the prelesion ones despite some long-term deficits such as paw drag and disrupted fore-hindlimb coupling. Nine out of ten tested cats could step over obstacles placed on the treadmill. Acute electrophysiological experiments showed viable connectivity between segments rostral and caudal to the contusion. At the fifth postcontusion week, a complete spinalization was performed at T13 in 10 cats and all expressed remarkable bilateral hindlimb locomotion within 24-72 h. From our histological evaluation, we concluded that only a small percentage (~10%) of spinal cord pathways was necessary to initiate and maintain a voluntary quadrupedal locomotor pattern on a treadmill and even to negotiate obstacles. Our findings suggest that hindlimb stepping largely resulted from the activity of spinal locomotor circuits, which gradually recovered autonomy week after week. Our histological and electrophysiological evidence indicated that the persistence of specific deficits or else the maintenance of specific functions was related to the integrity of specific supraspinal and propriospinal pathways. The conclusion is that the recovery of locomotion after large spinal contusions depends on a homeostatic recalibration of a tripartite control system involving interactions between spinal circuits (central pattern generator), supraspinal influences, and sensory feedback activated through locomotor training.NEW & NOTEWORTHY The recovery of quadrupedal treadmill locomotion after a large bilateral contusion at the low thoracic T10 spinal level and the ability to negotiate obstacles were studied for 5 wk in 16 cats. Ten cats were further completely spinalized at T13 and were found to walk with the hindlimbs within 24-72 h. We conclude that the extent of locomotor recovery after large spinal contusions hinges both on remnant supraspinal pathways and on a spinal pattern generator.

The Natural History of Ossification of Yellow Ligament of the Thoracic Spine on MRI: A Population-Based Cohort Study.

Purpose:To assess the natural history of ossification of yellow ligament (OYL) in the thoracic spine and determine risk factors for progression based on a longitudinal population-based cohort.Methods:A prospective, longitudinal cohort study was performed on a population-based cohort of Southern Chinese volunteers. T2-weighted magnetic resonance imaging (MRI) was used at baseline to identify any OYL and was verified with computed tomography. Follow-up MRI was performed 5 years later. Parameters under study included the size of OYL, levels of involvement, morphology (round, triangular, beak), whether it crossed the midline and any disc degeneration.Results:A total of 114 (6.1%) individuals were identified to have OYL at baseline out of the 1864 individuals. Size progression occurred predominantly at the lower thoracic region. Majority of the new OYL were also in the lower thoracic spine and was associated with higher body mass index (BMI). Smokers were associated with OYL size progression while patients with higher BMI tended to develop new OYL at follow-up. Progression commonly occurred at the lower thoracic levels and regression occurred mostly at the upper thoracic levels.Conclusions:This is the first population-based series addressing the natural history of OYL. Better understanding of the natural history of OYL may provide incentive to introduce preventive measures such as weight reduction and close monitoring for myelopathy development in those at-risk groups for progression. This is especially important for patients with lower thoracic OYL and who are smokers with higher BMI.Level of Evidence:1 (prognostic study).