Posterolateral Lesions Research Articles

Spinal Lesions in Axial Psoriatic Disease: How Should They Be Identified and Quantified by Magnetic Resonance Imaging?

Proper assessment of patients with psoriatic arthritis (PsA) requires assessment of all disease domains, including axial disease. Magnetic resonance imaging (MRI) is the method of choice for evaluating axial involvement in PsA. When assessing patients with PsA for spinal involvement, it is important to assess both vertebral body lesions and posterolateral lesions, such as inflammation in facet joints and costovertebral joints, and enthesitis at spinous and transverse processes. The Canada-Denmark (CanDen) assessment system for spine MRIs is the preferred method for detailed evaluation of inflammation and structural damage at various anatomical locations in the spine, and it is reproducible and sensitive to change. The Assessment of Spondyloarthritis international Society (ASAS) has recently published MRI definitions of inflammatory and structural lesions in the spine, incorporating the CanDen definitions of spinal lesions on MRI. Applying the ASAS definitions and the CanDen assessment system in clinical practice and trials is recommended. Ongoing research/studies, not least the Axial Involvement in Psoriatic Arthritis (AXIS) study, may provide a data-driven definition of axial involvement in PsA. Ongoing research is expected to further improve and validate assessment tools for axial PsA and to provide a much-needed data-driven consensus-based definition of axial involvement in PsA.

QOL-16. IMPACT OF LESION LOCATION ON MOTOR AND COGNITIVE OUTCOMES IN PEDIATRIC CEREBELLAR TUMORS

Abstract BACKGROUND Children with cerebellar damage are at increased risk for various adverse outcomes, including higher rates of autism and long term neurocognitive challenges. Traditionally considered a motor structure, extensive evidence links the cerebellum to a range of behaviors and atypical cerebellar structure and function have been reported in multiple neurodevelopmental and psychiatric conditions. A key feature of cerebellar neuroanatomy are the functional subregions that support sensorimotor and non-motor functions, leading to the hypothesis that motor, cognitive and behavioral outcomes should be predicted by the cerebellar lesion location.We aimed to determine how lesion location relates to outcomes in pediatric cerebellar patients. We predicted that lesions of the anterior lobe would disrupt motor performance, posterolateral lesions would impact cognitive functions, and behavioral dysregulation would be associated with posterior midline damage. METHODS We conducted lesion-symptom mapping in 30 children with a history of cerebellar tumor resection (sex: 19 male, 11 female; age at diagnosis, mean 6.8 years [SD 4.2]). Clinical MRI scans and neuropsychological data were used to evaluate the impact of lesion location on motor (pegboard), cognitive (verbal comprehension, verbal fluency, working memory, processing speed) and behavioral control measures (BRIEF). We mapped individual lesions using T1-weighted MRIs and normalized the lesion maps into standard template space for group analyses. RESULTS Behavioral scores ranged from impaired to above average. Lesion overlap maps were used to assess the lesion patterns associated with performance. As predicted, anterior and medial lesions disrupted motor performance and processing speed; posterolateral lesions were associated with impaired cognitive scores. CONCLUSIONS These preliminary analyses indicate that long-term outcomes are associated with disruption of specific cerebellar subregions. This could aid in prognosis and management of pediatric cerebellar tumor patients. Future work will address age of surgery, longitudinal changes in performance, and the developmental impact of early cerebellar disruption on supratentorial structures.

Look for the POLESTAR (POsteroLateral Engagement of Soft Tissue And Radial head) while navigating around elbow dislocation

IntroductionElbow dislocation is frequently associated with bony and osteochondral postero-lateral capitellar lesions that are often under-reported. We aim to examine the radiological signs of postero-lateral lesions on Computer Tomography (CT) . MethodsA retrospective analysis of CT scans was performed. Patients were classified into 4 groups: 1) simple elbow dislocation, 2) elbow dislocation with a fracture of the coronoid tip, 3) elbow dislocation with coronoid tip fracture and a radial head fracture inferior or equal to the anterior third, 4) terrible triad defined as elbow dislocation with concomitant coronoid and a radial head fracture with a more important involvement. Patients with a more complex fracture pattern were excluded. The presence of POstero Lateral Engagement of Soft Tissue And the Radial head (POLESTAR) patterns was analyzed and subclassified as impaction type or fragmentation type. Results51 CT scans met the inclusion criteria. POLESTAR lesions were identified in 48 cases (94%): 46% impaction type and 54% fragmentation type POLESTAR. Analyzing patients from grade 1 to 4, impaction type POLESTAR was found respectively from 40% to 57%, while fragmentation type was present from 60% to 43%. ConclusionsThis study shows a high incidence of POLESTAR lesions (94%) that can be present as impaction type or fragmentation type. Based on our preliminary results, impaction type is more common in Grades 3 and 4, while fragmentation type is more frequent in grades 1 or 2.

Effectiveness of arthroscopic excision based on the distribution of the tenosynovial giant cell tumor around knee joint

BackgroundThe mainstay treatment for tenosynovial giant cell tumor (TGCT) is open excision. However, open excision is associated with the risk of stiffness, infection, neurovascular injury, and prolonged hospital stay and rehabilitation. The purpose of this study was to evaluate the efficacy of arthroscopic excision of tenosynovial giant cell tumor (TGCT) of the knee joint, including the diffuse type of TGCT. MethodsPatients who underwent arthroscopic excision of TGCT between April 2014 and November 2020 were retrospectively analyzed. TGCT lesions were divided into 12 distributions (nine intra- and three extra-articular lesions). The distribution of TGCT lesions, portals used, degree of excision, recurrence, and magnetic resonance imaging (MRI) scans were evaluated. The prevalence of intra-articular lesions in diffuse TGCT was also analyzed to validate the existence of a connection between intra- and extra-articular lesions. ResultsTwenty-nine patients were included in the study. Fifteen patients (52%) had localized TGCT, and 14 patients (48%) had diffuse TGCT. The recurrence rates for localized, and diffuse TGCT were 0%, and 7%, respectively. Intra-articular posteromedial (i-PM), intra-articular posterolateral (i-PL), and extra-articular posterolateral (e-PL) lesions were found in all patients with diffuse TGCT. The prevalence rates of i-PM and i-PL lesions among e-PL lesions were both 100% (p = 0.026 and p < 0.001, respectively). Diffuse TGCT lesions were managed with posterolateral capsulotomy and viewed from the trans-septal portal. ConclusionsArthroscopic excision of TGCT was effective in both localized and diffuse TGCT. However, diffuse TGCT was associated with posterior and extra-articular lesions. Therefore, technical modification such as posterior, trans-septal portal, and capsulotomy were required. Study designRetrospective case series; level Ⅳ.

Efficacy of percutaneous cryoablation of renal cell carcinoma in older patients with medical comorbidities: Outcome study in 70 patients.

The aim of this study was to establish the efficacy of cryoablation for incidentally discovered small renal cell carcinomas in older patients with medical comorbidities. We carried out a retrospective chart analysis of outcomes of 70 patients treated by cryoablation. The inclusion criteria were age >56 years, medical comorbidities (Charlson class I-III), and suitability for cryoablation established by urologists and interventional radiologists. In total, 43 patients were male, 27 female, and the age range was 56 to 89. The lesions measured 1.5 to 4 cm; 29 were high-grade Fuhrman and 41 were low grade. All lesions were treated by 2 10-minute freezing cycles separated by an 8-minute thawing period. One to seven cryoprobes were inserted according to a preoperative, 3D computed tomography (CT)-based plan. Results were assessed on follow-up CTs (at 8-9 months). Of the 70 patients, 68 were treated by cryoablations and surgical salvage procedures; these patients were free of disease for 23 to 72 months (mean 39). One patient experienced recurrence and the other was lost to follow-up. One or two cryoablations rendered 66 patients tumour-free and additional surgery rendered another 2 patients tumour-free. The location and configuration of the lesion affected outcomes. Of the 27 posterior lesions, there was 1 failure; of the postero-lateral lesions, there were 4 failures; of the anterior lesions, there were 5 lesions; finally of the 32 central or deep seated lesions, there were 9 failures. Implants with one and two cryoprobes had a high recurrence rate. Three major complications were managed by minor interventions. The mean hospitalization was 1.3 days and the procedure times were variable. Percutaneous cryoablation is recommended as a minimally invasive nephron-sparing treatment for amenable lesions in older patients with medical comorbidities.

Incidence and distribution of occluded culprit arteries and impact of coronary collaterals on outcome in patients with non-ST-segment elevation myocardial infarction and early invasive treatment strategy

It is assumed that patients with non-ST-elevation myocardial infarctions (NSTEMI) showing an infero- or posterolateral occluded culprit artery (OCA) during diagnostic angiography frequently elude standard 12-lead electrocardiogram diagnosis. In addition, coronary collaterals may have beneficial effects in patients with OCA. We examined 448 consecutive NSTEMI patients within 72 h of symptom onset. All patients underwent early invasive angiography plus optimal medical therapy. We compared clinical characteristics and 30-days/6-month major adverse cardiovascular events (MACE) between patients with OCA and non-OCA. The secondary objective was to investigate the effect of angiographically visible coronary collaterals on 6-month MACE in patients with OCA. The angiograms revealed OCA in 130 (29%) of 448 patients. Patients with OCA showed more often infero- or posterolateral lesions (75 vs. 53%, p < 0.001) and more collaterals (57 vs. 8%, p < 0.001) compared with those with non-OCA. Patients with OCA had larger infarcts (peak CK-MB 2.1 ± 2.3 vs. 1.2 ± 1.1 μmol/L/s, p < 0.001), lower left ventricular ejection fraction (42 ± 21 vs. 48 ± 20%, p = 0.01), were more often revascularized (89 vs. 78%, p = 0.005), and had higher risk-adjusted 6-month MACE largely driven by its association with non-fatal reinfarctions (HR 2.16, 95% CI 1.04-4.50, p = 0.04). Patients with OCA and angiographically absent collaterals had significantly higher risk-adjusted 6-month MACE than those with OCA and angiographically visible collaterals (HR 1.96, 95% CI 1.02-3.76, p = 0.04). Approximately one-fourth of patients with NSTEMI revealed OCA that was more frequently found in coronary arteries supplying the infero- or posterolateral myocardium. Patients with OCA had larger infarcts and more non-fatal reinfarctions than patients with non-OCA. Well-developed collaterals may limit the myocardial damage in these patients.

Mood and Neurobehavioral Correlates of Cerebellar Lesions

The authors studied mood disorder and neurobehavioral correlates of solitary focal cerebellar (CB) lesions. CB function has been correlated with cognitive, behavioral, and psychiatric conditions. Systematic study of uncomplicated CB pathology can further our understanding of these correlates. Magnetic Resonance Images were blindly selected from 20,000 scans for solitary focal CB lesions after excluding other pathology. "Secondary" conditions (developing after lesion onset) were determined using structured clinical interviews (DIS and SCID) for psychiatric diagnoses while blind to MRI findings. Clinical correlates of lesions and a priori hypotheses were examined in 13 participants while controlling for alternative attributions (atrophy, hyperintensities, ventriculomegaly, disability, etc.). Bipolar disorders after CB lesions were more common than expected in normal populations (OR 28.62, 95% CI 3.51 < - >233.34, P=0.0001), replicating a previous finding. Secondary DSM-III and -IV depressive disorders correlated with posterolateral lesions of the right CB posterior lobe (P=0.0035); severity correlated with lesion size. Other lesion correlates included hypomania (anterolateral left CB posterior lobe), apathy (medial left anterior lobe, anterolateral right posterior lobe), disinhibition and dysexecution (medial left anterior lobe), agitation (central left and anterolateral right posterior lobe), and elation (anterolateral right posterior lobe). Although other structural cerebral and psychosocial variables did not explain the findings, much larger sample sizes will be needed to adequately control for these variables. Review of the literature reveals support for these findings, suggesting CB control of mood, behavior, and frontal cognition.

Surgery of Craniocervical Meningiomas

Objective: To study the different surgical approaches to craniocervical meningiomas in different locations in the area of the foramen magnum, whether anterior, posterior, antrolateral or posterolateral Methods: Twenty six patients with craniocervical meningiomas were operated upon during the period from 2000 to 2009 using the standard posterior approach for posterior lesions (14 cases), extreme lateral approach without drilling of the occipital condyle in the antrolateral and posterolateral lesions(6 cases) and transcondylar approach for anterior lesions (6 cases). Results: This study included 16 females and 10 males, the patients’ age ranged from 23 to 64 years with a mean of 51.8 years. Tumor size ranged from2 to 6.4 in its maximum diameter. Tumor location was posterior in 14 patients, lateral in 6 patients and anterior in 6 patients. Total tumor resection was done in 23 (88.4%) patients and subtotal in 3 (11.6%) patients. Postoperative complications included transient lower cranial nerves affection, transient hemiparesis. There was no mortality in this study. The follow up period ranged from 6 months to 4.8 years. Conclusion: Surgical approach to craniocervical meningioma has to be tailored according to the location of the tumor. Posterior tumors are safely totally removed through the slandered suboccipital approach. Posterolateral and antrolateral tumors are easily removed via the postero lateral retrocondylar approach without drilling of the occipital condyle benefiting from the working space given by lateral displacement of the brain stem. Anteriorly located tumors are better approached through the extreme lateral transcondylar approach to avoid brain stem retraction. Key words: Foramen magnum, meningioma, occipital condyle, suboccipital approach.

A Quantitative Comparison of Surgical Approaches for Posterolateral Osteochondral Lesions of the Talus

A Quantitative Comparison of Surgical Approaches for Posterolateral Osteochondral Lesions of the Talus

Correlation of outcome to neurosurgical lesions: confirmation of a new method using data after microelectrode-guided pallidotomy

The purpose of this study was the development of a new method to correlate functional surgery with outcome measures. Lesions following microelectrode guided globus pallidus internus (GPi) pallidotomy for Parkinson's disease are presented to demonstrate this new method in regard to clinical outcome. A clinical series of 26 patients with extensive neurological and neuropsychological data were studied. Three-month postoperative MRI lesion borders at the AC–PC plane were scaled to a standard size, and the lesions were stored in a virtual array with a cell size of one voxel. The average outcome measure for each voxel is presented graphically. Unified Parkinson's disease rating scale (UPDRS) motor scores improved more with posterolateral and centrally located GPi lesions than with anteromedial lesions. A correlation of lesion location to outcome was also visible for subscales of the UPDRS. The distributions were similar for the left and right sides, as well as for ipsi- and contralateral measurements. In general, verbal fluency decreased after lesioning the dominant hemisphere, and posterolateral lesions caused less impairment. This method enables associative analyses between brain area and outcome down to the size of a few voxels. This may be particularly helpful for planning and validating neurosurgical targets for various disorders.

Arthroscopic Treatment of Pigmented Villonodular Synovitis of the Knee

Purpose : To evaluate the efficacy of arthroscopic synovectomy through the direct posteriorposterior approach in pigmented villonodular synovitis (PVNS) of the knee. Materials and Methods : Between January 1997 and May 2004, twenty-one patients underwent an arthroscopic synovectomy for PVNS of knee. The mean follow-up period was 35 months. The arthroscopic and MRI findings revealed the localized form of PVNS in six patients and the diffuse form in fifteen patients. All patients underwent an arthroscopic examination and synovectomy through the direct posterior-posterior approach. The clinical results were evaluated by the range of motion, Lysholm knee score, and the knee pain score using the visual analogue scale (minimum 0-maximum 10). Results : Among the fifteen cases with the diffuse form, three cases (14%) recurred and had secondary arthroscopic total synovectomy. One cases recurred again. Therefore, radiation therapy was performed. The Lysholm knee score improved from 62.5 to 87.3, and the VAS score improved from 5.9 to 1.8. Three patients had a mild limitation in knee motion. However, the others had full range of motion of the knee at the last follow-up. Conclusion : Arthroscopic synovectomy through the direct posterior-posterior approach could be a useful method for the treatment of PVNS of the knee, and can be used as an effective therapeutic tool particularly in posteromedial or posterolateral lesions.

Post-Training Lesions of the Medial Prefrontal Cortex Interfere with Subsequent Performance of Trace Eyeblink Conditioning

Rabbits were trained on trace eyeblink (EB) conditioning until they reached a criterion of 10 consecutive EB conditioned responses (CRs). Electrolytic lesions were made in the medial prefrontal cortex (mPFC) centered on the prelimbic area (Brodmann's area 32), at five different intervals after training. These included immediately, 24 h, 1 and 2 weeks, and 1 month after training. Separate groups of animals received sham lesions at these same intervals after training. After a 2 week postoperative recovery period, all animals were retested for 3 d on trace conditioning, using the same parameters used during preoperative training. Mean EB conditioning performance deficits occurred in the animals with mPFC lesions compared with sham-lesioned animals on the first day of retesting in all five groups. However, by the second or third day of retesting, the rabbits with lesions were performing at a level that was comparable with that of sham animals. Rabbits that received more posterolateral lesions of the neocortex did not, however, show postoperative conditioning deficits. A comparison of percentage EB CRs of animals with postoperative training with that of animals that received mPFC lesions before training suggests that the mPFC post-training lesions produce damage to a retrieval process and not to a storage site or an acquisition process.

TRANSPERITONEAL VERSUS RETROPERITONEAL LAPAROSCOPIC PARTIAL NEPHRECTOMY: PATIENT SELECTION AND PERIOPERATIVE OUTCOMES

We compared the results of transperitoneal (T) and retroperitoneal (R) approaches to laparoscopic partial nephrectomy (LPN) in regard to perioperative outcomes and technical considerations, thereby, identifying patient selection guidelines for each approach. The choice of approach was dictated primarily by tumor location, that is TLPN for anterior or lateral lesions and RLPN for posterior or posterolateral lesions. The approaches differed primarily by the hilar control technique. During TLPN en bloc hilar control was achieved with a Satinsky clamp, while during RLPN individual vessel control was obtained with bulldog clamps. In a 3-year period 100 TLPNs and 63 RLPNs were performed for renal tumor. Of posterior tumors 77% were managed by RLPN, whereas 97% of anterior tumors were managed by TLPN. TLPN was associated with significantly larger tumors (3.2 vs 2.5 cm, p <0.001), more caliceal suture repairs (79% vs 57%, p = 0.004), longer ischemia time (31 vs 28 minutes, p = 0.04), longer operative time (3.5 vs 2.9 hours, p <0.001) and longer hospital stay (2.9 vs 2.2 days, p <0.01) than RLPN. Blood loss, perioperative complications, postoperative serum creatinine, analgesic requirements and histological outcomes were comparable between the groups. We perform TLPN for all anterior or lateral tumors as well as for large or deeply infiltrating posterior tumors that require substantive resection (heminephrectomy). The limited retroperitoneal space makes RLPN technically more challenging but provides superior access to posterior and particularly posteromedial lesions. When feasible, we prefer to perform laparoscopic partial nephrectomy by the transperitoneal approach because of its larger working area and superior instrument angles for intracorporeal renal reconstruction.

Squamous Vulvar Cancer: A Clinically Based Individualization of Treatment

Objective. The aim of the study was to evaluate treatment results in 211 patients with previously untreated squamous cell vulvar cancer who were primary managed by surgery at the Gynecologic Oncology Unit of Alexandra Hospital, in terms of en bloc radical vulvectomy (N = 105), modified radical vulvectomy with three different incisions technique (N = 60), and radical hemivulvectomy (N = 46) with inguinofemoral lymphadenectomy.Methods. The surgical stage of disease, nodal status, lesion location and focality, marginal status, tumor size, physical and performance status, surgical modality used, and finally complications and recurrence rates were the analyzed factors for both survival and disease remission.Results. The overall 5-year survival was 70.1%. The 5-year survival for node-positive patients was 53.8% versus 79.7% for node-negative patients. Unifocal lesions had a 5-year survival of 76% compared with 50% of multifocal lesions. Posterolateral lesions had a better 5-year survival than that of anterior central lesions (79.5% vs 54.4%). The marginal status of the surgical specimen was a significant predictor of both survival and recurrence. There was a significant difference in complications related to the en bloc radical vulvectomy in terms of wound breakdown, infection, and wound cellulitis.Conclusions. Modified radical procedures are equally effective with the en bloc radical vulvectomy for the management of early (stage I/II) vulvar cancer. In advanced disease concervative surgery in an individualized approach could also effectively be applied.

Relationship of lesion location to cognitive outcome following microelectrode-guided pallidotomy for Parkinson's disease: support for the existence of cognitive circuits in the human pallidum.

Current models of basal ganglia anatomy posit the existence of multiple parallel, anatomically segregated circuits. Anatomical data from non-human primates suggest that the circuits subserving motor functions are segregated from those subserving cognitive functions. Here we present data that demonstrate that, in humans, motor and cognitive frontosubcortical circuits are segregated. We studied a group of patients with Parkinson's disease undergoing surgical lesioning of the globus pallidus internus for relief of their symptoms. Lesion location along an anteromedial-to-posterolateral axis was found to be related to postsurgical outcome on both cognitive and motor measures. Performance on several neuropsychological measures, including the generation of category exemplars and continuous mental addition, was linearly related to distance along this axis, with anteromedial lesions leading to postsurgical impairment, intermediate lesions having little effect and posterolateral lesions leading to an improvement on several measures. The same relationship was found between memory performance under conditions of proactive interference and lesion location within the globus pallidus internus. In contrast, bradykinesia, assessed as the speed of finger-tapping, had a non-linear relationship to lesion location, intermediate lesions leading to greater postsurgical improvement than lesions in more extreme anteromedial or posterolateral locations. These data demonstrate that the cognitive effects of pallidotomy can be dissociated from the motor effects. These effects depend upon the placement of the lesions within the globus pallidus internus, supporting the segregation of functionally distinct circuits in the human pallidum.

Facilitation and inhibition of gastric pathology after lesions in the amygdala of rats

Bilateral lesions in the dorsomedial amygdala attenuated the effects of physical restraint on stomach pathology in rats. Posterolateral lesions increased the incidence and severity of gastric ulcers and hemorrhages. Combined lesions in these two amygdaloid areas also attenuated the restraint-induced pathology. It was concluded that the dorsomedial amygdala is excitatory, whereas the posterolateral area is inhibitory during restraint stress.

Dynamic changes in brain dopamine-β-hydroxylase activity during anterograde and retrograde reactions to injury of central noradrenergic axons

(1) Changes in the activity of the enzyme dopamine-β-hydroxylase (DBH), a specific marker of noradrenergic neurons, were measured in several brain areas following unilateral electrolytic lesions in the posterolateral hypothalamus in order to evaluate the dynamics of anterograde and retrograde responses to injury in noradrenergic neurons. (2) In the ipsilateral cerebral cortex, a site of degenerating axon terminals, DBH activity fell to 30% of control by 14 days after a lesion and remained at this low level for up to 45 days. (3) In the contralateral cerebral cortex, DBH activity fell transiently by day 7, recovered by day 14, and then overshot control values by day 21 to reach 12% of control. (4) In the ipsilateral brain stem, a site of noradrenergic cell bodies, DBH activity rose during the first 48 h to 135% of control, next fell to 50% of control by days 7–14, and finally recovered to control levels by day 21. The changes in DBH activity in the contralateral brain stem were similar in form and timing but were of diminished magnitude. (5) In the ipsilateral, but not contralateral, cerebellum, a site of collateral axons from ascending noradrenergic neurons from the locus coeruleus, DBH activity changed in parallel with that of the ipsilateral brain stem. (6) In the ipsilateral, but not contralateral, area of the locus coeruleus, a site of cell bodies of noradrenergic neurons, DBH activity was reduced to 52% of control by 12 days after a lesion and returned to normal by 28 days. (7) Unlike posterolateral lesions, lesions of the anterolateral hypothalamus, while also interrupting ascending noradrenergic axons, failed to alter the DBH activity in the brain stem. (8) We conclude: (a) The permanent fall of DBH activity in the ipsilateral cortex represents anterograde degeneration in noradrenergic axon terminals. (b) The reversible fall in DBH activity in brain stem and locus coeruleus reflects a retrograde reaction of cell bodies of noradrenergic neurons to injury. This fall is probably due to a reduction in amount of enzyme protein. (c) The reversible changes in DBH activity in cerebellum are a reflection in uninjured (‘sustaining’) collaterals of the retrograde response of noradrenergic neurons of locus coeruleus to lesions of axons ascending in the hypothalamus. (9) The results suggest: (a) During the retrograde (‘chromatolytic’) reaction, there may be a selective decrease in the production of proteins subserving neurotransmitter biosynthesis. (b) A neuron signals metabolic events induced by lesions of a single axon to intact, remotely situated collaterals. This mode of intraneuronal communication is a mechanism whereby information of nonsynaptic events in widely ramified neurons may be transferred between remote areas of brain.