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1.
J Imaging Inform Med ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871944

RESUMO

The majority of deep learning models in medical image analysis concentrate on single snapshot timepoint circumstances, such as the identification of current pathology on a given image or volume. This is often in contrast to the diagnostic methodology in radiology where presumed pathologic findings are correlated to prior studies and subsequent changes over time. For multiple sclerosis (MS), the current body of literature describes various forms of lesion segmentation with few studies analyzing disability progression over time. For the purpose of longitudinal time-dependent analysis, we propose a combinatorial analysis of a video vision transformer (ViViT) benchmarked against traditional recurrent neural network of Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM) architectures and a hybrid Vision Transformer-LSTM (ViT-LSTM) to predict long-term disability based upon the Extended Disability Severity Score (EDSS). The patient cohort was procured from a two-site institution with 703 patients' multisequence, contrast-enhanced MRIs of the cervical spine between the years 2002 and 2023. Following a competitive performance analysis, a VGG-16-based CNN-LSTM was compared to ViViT with an ablation analysis to determine time-dependency of the models. The VGG16-LSTM predicted trinary classification of EDSS score in 6 years with 0.74 AUC versus the ViViT with 0.84 AUC (p-value < 0.001 per 5 × 2 cross-validation F-test) on an 80:20 hold-out testing split. However, the VGG16-LSTM outperformed ViViT when patients with only 2 years of MRIs (n = 94) (0.75 AUC versus 0.72 AUC, respectively). Exact EDSS classification was investigated for both models using both classification and regression strategies but showed collectively worse performance. Our experimental results demonstrate the ability of time-dependent deep learning models to predict disability in MS using trinary stratification of disability, mimicking clinical practice. Further work includes external validation and subsequent observational clinical trials.

2.
Am J Otolaryngol ; 44(4): 103858, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37001393

RESUMO

PURPOSE: There are limited guidelines for diagnosing and managing chronic rhinosinusitis (CRS) in the cystic fibrosis (CF) population. While CF patients are known to have significant opacification on paranasal computed tomography (CT), limited evidence suggests that CT findings are not indicative of patients' symptom burden and therefore not a reliable indicator for surgical intervention. This provides a diagnostic challenge for otolaryngologists taking care of this patient population. The purpose of this study is to better define the relationship between objective imaging findings and patients' symptom severity in the CF-CRS population with the goal of providing more selective and effective patient care. MATERIALS AND METHODS: In this retrospective cohort study, 67 patients with CF CRS had their CT scans scored according to a modified Lund Mackay CT score (LMCTS), which was compared to their Sinonasal Outcome Test scores (SNOT-22). Total SNOT-22 and individual domains were evaluated. Pearson's correlation was performed. RESULTS: The overall mean SNOT-22 score was 32.3. The mean LMCTS was 17.6. These metrics correlate with relatively low subjective symptom scores in comparison to the high objective presence of sinus disease. While patients had high LMCTS, there was no correlation found between LMCTS and total SNOT-22 or individual SNOT-22 domains. CONCLUSIONS: CT findings in CF CRS patients do not accurately reflect patients' symptom burden and should not be used as a primary driver in the clinical management of these patients.


Assuntos
Fibrose Cística , Rinite , Sinusite , Humanos , Fibrose Cística/complicações , Fibrose Cística/diagnóstico por imagem , Estudos Retrospectivos , Rinite/diagnóstico por imagem , Rinite/etiologia , Sinusite/diagnóstico por imagem , Sinusite/etiologia , Doença Crônica , Tomografia Computadorizada por Raios X/métodos
3.
Stroke ; 52(4): 1164-1171, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33626904

RESUMO

BACKGROUND AND PURPOSE: It is unknown when to start anticoagulation after acute ischemic stroke (AIS) from atrial fibrillation (AF). Early anticoagulation may prevent recurrent infarctions but may provoke hemorrhagic transformation as AF strokes are typically larger and hemorrhagic transformation-prone. Later anticoagulation may prevent hemorrhagic transformation but increases risk of secondary stroke in this time frame. Our aim was to compare early anticoagulation with apixaban in AF patients with stroke or transient ischemic attack (TIA) versus warfarin administration at later intervals. METHODS: AREST (Apixaban for Early Prevention of Recurrent Embolic Stroke and Hemorrhagic Transformation) was an open-label, randomized controlled trial comparing the safety of early use of apixaban at day 0 to 3 for TIA, day 3 to 5 for small-sized AIS (<1.5 cm), and day 7 to 9 for medium-sized AIS (≥1.5 cm, excluding full cortical territory), to warfarin, in a 1:1 ratio at 1 week post-TIA, or 2 weeks post-AIS. RESULTS: Although AREST ended prematurely after a national guideline focused update recommended direct oral anticoagulants over warfarin for AF, it revealed that apixaban had statistically similar yet generally numerically lower rates of recurrent strokes/TIA (14.6% versus 19.2%, P=0.78), death (4.9% versus 8.5%, P=0.68), fatal strokes (2.4% versus 8.5%, P=0.37), symptomatic hemorrhages (0% versus 2.1%), and the primary composite outcome of fatal stroke, recurrent ischemic stroke, or TIA (17.1% versus 25.5%, P=0.44). One symptomatic intracerebral hemorrhage occurred on warfarin, none on apixaban. Five asymptomatic hemorrhagic transformation occurred in each arm. CONCLUSIONS: Early initiation of anticoagulation after TIA, small-, or medium-sized AIS from AF does not appear to compromise patient safety. Potential efficacy of early initiation of anticoagulation remains to be determined from larger pivotal trials. Registration: URL: https://www.clinicaltrials.gov/; Unique identifier: NCT02283294.


Assuntos
Fibrilação Atrial/complicações , Inibidores do Fator Xa/administração & dosagem , AVC Isquêmico/etiologia , Pirazóis/administração & dosagem , Piridonas/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Hemorragia Cerebral/epidemiologia , Hemorragia Cerebral/etiologia , Feminino , Humanos , AVC Isquêmico/prevenção & controle , Masculino , Pessoa de Meia-Idade , Recidiva
4.
Radiol Case Rep ; 15(12): 2649-2654, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33093931

RESUMO

Neurenteric cysts are uncommon, benign lesions that are rarely located intracranially. These cysts are likely due to aberrant embryologic development of the notochord. Clinically, neurenteric cysts may present with symptoms of mass effect, or they can be asymptomatic and incidentally discovered. Imaging features of neurenteric cysts have significant overlap with other intracranial cystic lesions, which can make diagnosis difficult. We present a case of a 35-year-old female with a histopathologically confirmed neurenteric cyst in the premedullary and left cerebellomedullary cistern, with associated symptoms of headache, dizziness, tinnitus, and dysphagia. The patient underwent surgical resection, with improvement in symptoms. We present a review of literature, and a discussion of typical features of multiple intracranial cystic lesions. We hope to promote accurate preoperative diagnosis, to allow for appropriate surgical technique to reduce the risk of recurrence.

5.
Radiol Case Rep ; 15(9): 1433-1436, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32642012

RESUMO

Longus colli tendonitis is an uncommon aseptic inflammatory condition that affects the prevertebral longus colli tendon, which is a muscle that courses anteriorly from the level of the C1 to T3 vertebrae (1,2). Although longus colli tendonitis is a self-limited condition, the longus colli muscle is anterior to the prevertebral space and posterior to the pharyngeal constrictors, therefore when inflamed, leads to a myriad of symptoms that often mimic more serious conditions such as retropharyngeal abscess or meningitis (2). We present a case of a 39-year-old white male that presented with neck pain, neck stiffness, and pain with swallowing. Imaging findings on CT and MRI were consistent with a diagnosis of longus colli tendonitis. However, given the patient's presenting symptoms and elevated inflammatory lab markers, he was treated empirically with antibiotic therapy. This case report aims to educate on this condition and to discuss the diagnostic imaging findings to help avoid unnecessary treatments and interventions.

6.
World Neurosurg ; 136: e386-e392, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31931247

RESUMO

OBJECTIVE: To investigate whether sacroiliac join (SIJ) pain can be secondary to walking with a flexed posture resulting from stenosis with neurogenic claudication, and resolves spontaneously after lumbar decompression. METHODS: A review of charts from January 1, 2014, through March 3, 2019, was performed to identify consecutive cases of adults 35 years of age or older with surgical spinal stenosis with neurogenic claudication as well as concomitant severe SIJ pain. Posture was considered flexed during walking if self-reported, confirmed by a close companion, or observed directly. SIJ pain was diagnosed clinically ± confirmatory injection. A 10-point visual analog scale was used to assess SIJ pain. The primary endpoint was SIJ pain improvement at a minimum of 24 months' follow-up. SIJ pain improvement at 3 months was used to assess the rate of improvement as a secondary endpoint. RESULTS: Ten patients (3 female) met entry criteria: 4 were treated with decompression alone; 6 with decompression and spinal fusion. Mean SIJ visual analog scale pain score improved by 6.9 ± 2.4 (8.7 ± 1.6-1.8 ± 2.2; P < 0.0005). Results were similar for 20 patients at the secondary endpoint of 3 months. CONCLUSIONS: Sacroiliac joint pain shows robust, rapid, reliable, and durable improvement following lumbar decompressive surgery. The addition of a spinal fusion also leads to a similar improvement in SIJ pain. This study demonstrates the importance of evaluating the specific source of low back pain in patients with stenosis, claudication, and SIJ pain so as to more effectively plan appropriate surgery.


Assuntos
Dor Lombar/cirurgia , Vértebras Lombares/cirurgia , Fusão Vertebral/métodos , Estenose Espinal/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Descompressão Cirúrgica/instrumentação , Descompressão Cirúrgica/métodos , Feminino , Humanos , Claudicação Intermitente/etiologia , Laminectomia/instrumentação , Laminectomia/métodos , Dor Lombar/etiologia , Masculino , Pessoa de Meia-Idade , Medição da Dor , Parafusos Pediculares , Postura , Estudos Retrospectivos , Articulação Sacroilíaca , Fusão Vertebral/instrumentação , Estenose Espinal/complicações , Resultado do Tratamento
7.
Front Neurol ; 10: 975, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31620067

RESUMO

Background: Optimal timing to initiate anticoagulation after acute ischemic stroke (AIS) from atrial fibrillation (AF) is currently unknown. Compared to other stroke etiologies, AF typically provokes larger infarct volumes and greater concern of hemorrhagic transformation, so seminal randomized trials waited weeks to months to begin anticoagulation after initial stroke. Subsequent data are limited and non-randomized. Guidelines suggest anticoagulation initiation windows between 3 and 14 days post-stroke, with Class IIa recommendations, and level of evidence B in the USA and C in Europe. Aims: This open-label, parallel-group, multi-center, randomized controlled trial AREST (Apixaban for Early Prevention of Recurrent Embolic Stroke and Hemorrhagic Transformation) is designed to evaluate the safety and efficacy of early anticoagulation, based on stroke size, secondary prevention of ischemic stroke, and risks of subsequent hemorrhagic transformation. Methods: Subjects are randomly assigned in a 1:1 ratio to receive early apixaban at day 0-3 for transient ischemic attack (TIA), 3-5 for small-sized AIS (<1.5 cm), and 7-9 for medium-sized AIS (1.5 cm or greater but less than a full cortical territory), or warfarin at 1 week post-TIA or 2 weeks post-stroke. Large AISs are excluded. Study Outcomes: Primary: recurrent ischemic stroke, TIA, and fatal stroke; secondary: intracranial hemorrhage (ICH); hemorrhagic transformation (HT) of ischemic stroke; cerebral microbleeds (CMBs); neurologic disability [e.g., modified Rankin Scores (mRS), National Institutes of Health Stroke Scale (NIHSS), Stroke Specific Quality of Life scale (SS-QOL)]; and cardiac biomarkers [e.g., AF burden, transthoracic echo (TTE)/transesophageal echo (TEE) abnormalities]. Sample Size Estimates: Enrollment goal was 120 for 80% power (two-sided type I error rate of 0.05) to detect an absolute risk reduction of 16.5% postulated to occur with apixaban in the primary composite outcome of fatal stroke/recurrent ischemic stroke/TIA within 180 days. Enrollment was suspended at 91 subjects in 2019 after a focused guideline update recommended direct oral anticoagulants (DOACs) over warfarin in AF, excepting valvular disease (Class I, level of evidence A). Discussion: AREST will offer randomized controlled trial data about timeliness and safety of anticoagulation in AIS patients with AF. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02283294.

8.
Am J Ophthalmol Case Rep ; 15: 100517, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31372579

RESUMO

PURPOSE: To familiarize clinicians with the clinical and magnetic resonance imaging (MRI) features of a small orbital apex lymphaticovenous malformation that resulted in blindness and evaded timely clinical diagnosis. OBSERVATIONS: A 68-year-old man presented with severe vision loss due to a 9 mm mass at the apex of the orbit above the optic nerve. When surgically removed 4 years later, the lesion was characterized by vascular spaces of varying size. Larger ones were filled with fibrin and organized thrombi. Stromal septa of endothelial-lined cavernous spaces were partially necrotic and there was evidence of remote hemorrhage. Some endothelial cells expressed D2-40, a marker of lymphatic channels. CONCLUSIONS AND IMPORTANCE: Unless a high index of suspicion is maintained for a lymphaticovenous malformation the clinical diagnosis of a small but vision-threatening lesion can be overlooked.

9.
World Neurosurg ; 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30579030

RESUMO

BACKGROUND: Little published data exist regarding normal values of disc height. Current literature relies on plain radiographs making accurate measurements of individual lumbar disc height difficult. OBJECTIVE: We seek to establish normal values for lumbar intervertebral discs in different age groups using computed tomography scans in healthy individuals. METHODS: Two hundred forty anonymized abdominal computed tomography scans (131 women) were prospectively collected once institutional review board approval was obtained. Individuals with spinal pathologies were excluded. Disc height measurements were obtained at the anterior edge, center, and posterior edge of each vertebra in the midsagittal plane, averaged, and compared against age and sex. RESULTS: Average age was 45 (14-83) years for women and 48 (14-89) years for men. Average lumbar disc height was 5.6 ± 1.1 mm for men and 4.8 ± 0.8 mm for women at T12/L1, 6.9 ± 1.3 mm for men and 5.8 ± 0.9 mm for women at L1/2, 8.1 ± 1.4 mm for men and 6.9 ± 1.1 mm for women at L2/3, 8.7 ± 1.5 mm for men and 7.6 ± 1.2 mm for women at L3/4, 9.2 ± 1.6 mm for men and 8.5 ± 1.6 mm for women at L4/5, and 8.8 ± 1.6 mm for men and 8.6 ± 1.8 mm for women at L5/S1. Disc height was significantly smaller for women than men (P < 0.001), except at L5/S1. CONCLUSIONS: Variation in disc height is determined much more by sex than age. The maximum height of the interbody space in the adult lumbar spine was at the L4/5 level (8.9 ± 1.7 mm [men], 8.6 ± 1.8 mm [women]). Based on our findings, >10 mm cage height will result in supraphysiologic interbody space restoration and potentially predispose to complications.

10.
Acta Neurochir (Wien) ; 158(11): 2185-2193, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27566714

RESUMO

BACKGROUND: Diffusion tensor imaging (DTI) is a relatively new imaging modality that has found many peri-operative applications in neurosurgery. METHODS: A comprehensive survey of the applications of diffusion tensor imaging (DTI) in planning for temporal lobe epilepsy surgery was conducted. The presentation of this literature is supplemented by a case illustration. RESULTS: The authors have found that DTI is well utilized in epilepsy surgery, primarily in the tractography of Meyer's loop. DTI has also been used to demonstrate extratemporal connections that may be responsible for surgical failure as well as perioperative planning. The tractographic anatomy of the temporal lobe is discussed and presented with original DTI pictures. CONCLUSIONS: The uses of DTI in epilepsy surgery are varied and rapidly evolving. A discussion of the technology, its limitations, and its applications is well warranted and presented in this article.


Assuntos
Imagem de Tensor de Difusão/métodos , Epilepsia do Lobo Temporal/cirurgia , Procedimentos Neurocirúrgicos/métodos , Cirurgia Assistida por Computador/métodos , Imagem de Tensor de Difusão/efeitos adversos , Epilepsia do Lobo Temporal/diagnóstico por imagem , Humanos , Procedimentos Neurocirúrgicos/efeitos adversos , Cirurgia Assistida por Computador/efeitos adversos
11.
Radiology ; 278(3): 646-56, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26885732

RESUMO

Surgeons and radiologists have traditionally focused on frontal radiographs and the measurement of scoliosis curves as important tools in the management of spinal deformity. It has become evident, however, that the management of spinal deformity should use a multidimensional approach with an increased emphasis on standing lateral radiographs and the sagittal position of the spine. Furthermore, they have come to realize the critical role that the pelvis plays in the maintenance of posture. Failure to recognize pelvic compensation can lead to under-treatment and poor postoperative outcomes.


Assuntos
Pelve/diagnóstico por imagem , Escoliose/diagnóstico por imagem , Escoliose/cirurgia , Fenômenos Biomecânicos , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Vértebras Lombares/cirurgia , Pelve/fisiopatologia , Radiografia , Escoliose/fisiopatologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/fisiopatologia , Vértebras Torácicas/cirurgia
12.
Asian Spine J ; 8(3): 244-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24967037

RESUMO

STUDY DESIGN: Retrospective comparative study and technical note. PURPOSE: To determine if there is a difference in clinical and radiographic parameters between unilateral and bilateral kyphoplasty in a uniform cancer population and to stress the importance of preoperative planning. OVERVIEW OF LITERATURE: While unipedicular kyphoplasty is gaining popularity, a few comparative studies have reported on superior kyphotic reduction with the bipedicular approach. METHODS: We reviewed 69 myeloma patients with 105 operated levels (51 levels were done bilaterally vs. 54 unilaterally). Pain reduction, height restoration, cement volume and complications were recorded up to three months postoperatively. A technical note to identify the skin entry point on the basis of the magnetic resonance imaging and fluoroscopy (lateral view) is being described. RESULTS: Both procedures resulted in significant pain reduction (5.4-5.6/10 points, p=0.8). There was significant height restoration after the operation (p<0.001), while there was no sustained difference between the procedures (p=0.5) up to three months postoperatively. More cement was injected in the bilateral group (4.1 mL vs. 4.9 mL, p=0.002); no difference in cement extravasation in the spinal canal was observed (p=0.5). CONCLUSIONS: There was no difference in the clinical or radiological outcomes between the unilateral and bilateral approaches. Therefore, unilateral kyphoplasty may be performed whenever it is technically feasible and this may be determined preoperatively.

13.
Neuroimaging Clin N Am ; 24(2): 287-94, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24792608

RESUMO

The primary goal of motion preservation surgery in the spine is to maintain normal or near normal motion in an attempt to prevent adverse outcomes commonly seen with conventional spinal fusion, most notably the development of adjacent-level degenerative disc disease. Several different surgical approaches have been developed to preserve motion in the lumbar spine, including total disc replacement, partial disc (nucleus) replacement, interspinous spacers, dynamic stabilization devices, and total facet replacement devices. The design of devices varies greatly. The devices are created using a similar rationale but are unique in design relative to their lumbar counterparts.


Assuntos
Degeneração do Disco Intervertebral/prevenção & controle , Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Movimento/fisiologia , Complicações Pós-Operatórias/prevenção & controle , Amplitude de Movimento Articular/fisiologia , Fusão Vertebral/métodos , Substituição Total de Disco/métodos , Fenômenos Biomecânicos , Vértebras Cervicais/fisiopatologia , Vértebras Cervicais/cirurgia , Feminino , Humanos , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/fisiopatologia , Degeneração do Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/fisiopatologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Masculino , Complicações Pós-Operatórias/diagnóstico por imagem , Desenho de Prótese , Radiografia , Substituição Total de Disco/efeitos adversos
14.
Clin Orthop Relat Res ; 472(6): 1784-91, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24474321

RESUMO

BACKGROUND: The minimally invasive lateral transpsoas retroperitoneal approach to address lumbar stenosis offers advantages to traditional approaches, including sparing of the AP annulus and longitudinal ligament and less risk to the peritoneal contents and retroperitoneal vascular structures. Few studies have presented longitudinal measures of radiographic indirect decompression and relief of pain and restoration of function using the lateral approach to spine fusion. QUESTION/PURPOSES: We determined (1) whether radiographic measures suggestive of decompression were achieved after surgery and maintained 1 year after surgery, (2) whether the intervention resulted in sustained improvements in patient-reported outcomes scores 1 year after surgery, and (3) the frequency of pseudarthrosis on CT scans at 1 year after surgery in patients with moderate or severe lumbar stenosis treated with the approach. METHODS: Between 2008 and 2012, 158 patients were surgically treated to alleviate symptoms associated with degenerative lumbar stenosis, of whom 60 (38%) were treated with lateral lumbar interbody fusion. Of these 60 patients, 36 (60%) received CT scans preoperatively and at 1-year postoperatively and were available for radiographic analysis. Of the 60 treated patients, 16 (27%) were lost to followup before 12 months, leaving the records of 44 patients available for review of patient-reported improvements in pain and return to function. Radiographic increases in disc height, foraminal area, and canal area were measured by one observer on CT scans postoperatively and at 1 year and compared to preoperative values. Patient-reported scores, including VAS pain score and Oswestry Disability Index (ODI), were collected preoperatively and at 3 and 12 months postoperatively. RESULTS: Increases in disc height (67%, p < 0.001), foraminal area (24%-31%, p < 0.001), and canal area (7%, p = 0.011) measured immediately postoperatively were sustained at 1-year followup. VAS pain score and ODI both improved (p < 0.001) at 3 months and were maintained at 1 year. No pseudarthroses were noted radiographically. CONCLUSIONS: The lateral transpsoas approach to interbody fusion is capable of sustaining indirect decompression of the neural structures and resolving preoperative claudication and radiculopathy. A larger series of patients with longer followup should be studied to substantiate these early clinical results. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.


Assuntos
Descompressão Cirúrgica/instrumentação , Vértebras Lombares/cirurgia , Fusão Vertebral/instrumentação , Estenose Espinal/cirurgia , Idoso , Descompressão Cirúrgica/efeitos adversos , Descompressão Cirúrgica/métodos , Avaliação da Deficiência , Desenho de Equipamento , Feminino , Humanos , Dor Lombar/etiologia , Dor Lombar/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Medição da Dor , Pseudoartrose/etiologia , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Estenose Espinal/complicações , Estenose Espinal/diagnóstico , Estenose Espinal/fisiopatologia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
15.
J Spinal Disord Tech ; 27(5): 263-70, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23563336

RESUMO

STUDY DESIGN: Cadaveric Biomechanical and Radiographic Analysis. OBJECTIVE: The purpose of this study was to quantify the changes in intervertebral height and lateral and central recess areas afforded by lateral interbody fusion cages with 2 supplemental forms of internal fixation in cadaveric specimens. BACKGROUND DATA: When conservative treatment for symptomatic lumbar stenosis fails, traditional intervention has been direct posterior decompression. The minimally invasive, lateral transpsoas approach may be a viable alternative to direct decompression by providing restoration of the foraminal and intervertebral dimensions, yet few reports have examined the anatomic and radiographic changes that occur using this technique. METHODS: Computed tomography (CT) scans were taken of 18 intact lumbar (L1-S1) cadaveric specimens under a 400 N preload. Intervertebral height, foraminal areas, and canal area were measured at L3-L4 and L4-L5. Thereafter, the cadaveric specimens were instrumented with lateral cages placed in the central or posterior third of the disk space at L3-L4 and L4-L5 and either (1) lateral plate (n=9) or (2) bilateral posterior pedicle screw fixation (n=9). All constructs were again subjected to a 400 N preload, postinstrumentation CT scans were taken, and changes in intervertebral height and lateral and central recess areas were calculated. RESULTS: There was no effect of cage placement on any radiographic metric of indirect decompression for either fusion construct. In the lateral plate and pedicle screw groups, respectively, significant increases in average posterior disk height (30.9%, 60.1%), average right (35.3%, 61.5%) and left foraminal area (48.3%, 57.8%), and average canal area (32.3%, 33.3%) were observed. Pedicle screw instrumentation afforded a significantly greater increase in average posterior disk height and foraminal area compared with the lateral plate group, though there was no difference in the average increase in canal area afforded by either form of fixation. CONCLUSIONS: The radiographic results reported here using a cadaveric model add validity to the underlying rationale described for the minimally invasive lateral approach technique. Increases in disk height, foraminal and canal areas were not dependent on cage positioning within the disk space. As intraoperative placement of a cage in the central portion of the disk is an easier and safer technique, our results suggest that central placement may be preferable in a clinical setting.


Assuntos
Descompressão Cirúrgica/métodos , Fixação Interna de Fraturas/métodos , Vértebras Lombares/cirurgia , Fusão Vertebral/métodos , Estenose Espinal/cirurgia , Adulto , Idoso , Fenômenos Biomecânicos/fisiologia , Placas Ósseas , Parafusos Ósseos , Cadáver , Força Compressiva/fisiologia , Descompressão Cirúrgica/instrumentação , Feminino , Fixação Interna de Fraturas/instrumentação , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Região Lombossacral/diagnóstico por imagem , Região Lombossacral/fisiologia , Região Lombossacral/cirurgia , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Radiografia , Fusão Vertebral/instrumentação , Estenose Espinal/diagnóstico por imagem , Suporte de Carga/fisiologia
16.
Int J Spine Surg ; 7: e101-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25694896

RESUMO

BACKGROUND: The lateral transpsoas approach to interbody fusion is gaining popularity. Existing literature suggests that perioperative vertebra-related complications include endplate breach owing to aggressive enedplate preparation and poor bone quality. The acute effects of cage subsidence on stabilization and indirect decompression at the affected level are unknown. The purpose of this study was to compare the kinematics and radiographic metrics of indirect decompression in lumbar spines instrumented with laterally placed cages in the presence of inadvertent endplate fracture, which was determined radiographically, to specimens instrumented with lateral cages with intact endplates. METHODS: Five levels in 5 specimens sustained endplate fracture during lateral cage implantation followed by supplementary fixation (pedicle screw/rod [PSR]: n = 1; anterolateral plate [ALP]: n = 4), as part of a larger laboratory-based study. Range of motion (ROM) in these specimens was compared with 13 instrumented specimens with intact endplates. All specimens were scanned using computed tomography (CT) in the intact, noninstrumented condition and after 2-level cage placement with internal fixation under a 400-N follower load. Changes in disc height, foraminal area, and canal area were measured and compared between specimens with intact endplates and fractured endplates. RESULTS: Subsidence in the single PSR specimen and 4 ALP specimens was 6.5 mm and 4.3 ± 2.7 mm (range: 2.2-8.3 mm), respectively. ROM was increased in the PSR and ALP specimens with endplate fracture when compared with instrumented specimens with intact endplates. In 3 ALP specimens with endplate fracture, ROM in some motion planes increased relative to the intact, noninstrumented spine. These increases in ROM were paralleled by increase in cage translations during cyclic loading (up to 3.3 mm) and an unpredictable radiographic outcome with increases or decreases in posterior disc height, foraminal area, and canal area when compared with instrumented specimens with intact endplates. CONCLUSIONS: Endplate fracture and cage subsidence noted radiographically intraoperatively or in the early postoperative period may be indicative of biomechanical instability at the affected level concomitant with a lack of neurologic decompression, which may require revision surgery.

17.
Neuro Oncol ; 14(1): 93-100, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22028388

RESUMO

A phase I study was conducted to determine the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) for the combination of vorinostat with bevacizumab and CPT-11 in recurrent glioblastoma. Vorinostat was combined with bevacizumab and CPT-11 and was escalated using a standard 3 + 3 design. Vorinostat was escalated up to 2 actively investigated doses of this compound or until the MTD was identified on the basis of DLTs. Correlative science involving proteomic profiling of serial patient plasma samples was performed. Nineteen patients were treated. The MTD of vorinostat was established at 400 mg on days 1-7 and 15-21 every 28 days when combined with bevacizumab and CPT-11. Common toxicities were fatigue and diarrhea. DLTs included fatigue, hypertension/hypotension, and central nervous system ischemia. Although the MTD was established, CPT-11 dose reductions were common early in therapy. High-dose vorinostat had an improved progression-free survival and overall survival when compared with low-dose vorinostat. Serum proteomic profiling identified IGFBP-5 and PDGF-AA as markers for improved PFS and recurrence, respectively. A MTD for the combination of vorinostat with bevacizumab and CPT-11 has been established, although it has poor long-term tolerability. With the increased toxicities associated with CPT-11 coupled with its unclear clinical significance, investigating the efficacy of vorinostat combined with bevacizumab alone may represent a more promising strategy to evaluate in the context of a phase II clinical trial.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/toxicidade , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Bevacizumab , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Camptotecina/toxicidade , Intervalo Livre de Doença , Feminino , Humanos , Ácidos Hidroxâmicos/administração & dosagem , Ácidos Hidroxâmicos/toxicidade , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/análise , Irinotecano , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Fator de Crescimento Derivado de Plaquetas/análise , Proteômica , Vorinostat
18.
Radiology ; 260(2): 317-30, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21778450

RESUMO

Lumbar spinal fusion is a commonly performed procedure, and, despite changes in cage types and fixation hardware, radiologists have, over the years, become familiar with the imaging features of typical spinal fusion and many of the complications seen in patients after surgery, including pseudoarthrosis, hardware loosening, and recurrent or residual disk herniation. Recently, however, novel approaches and devices have been developed, including advances in minimally invasive surgery, the increasing use of osteoinductive materials, and a wide variety of motion-preserving devices. These new approaches and devices manifest with characteristic imaging features and the potential for unusual and unexpected complications. Several of these devices and approaches are experimental, but many, including those devices used in lateral approaches to fusion, as well as the use of bone morphogenic protein, disk arthroplasty, and interspinous spacers, are seen with increasing frequency in daily clinical practice. Given the recent advances in spinal fusion surgery, it is important that radiologists have a basic understanding of the rationale behind these procedures, the common imaging features of the devices, and the complications associated with their use.


Assuntos
Discotomia/instrumentação , Fixadores Internos , Vértebras Lombares/cirurgia , Imagem por Ressonância Magnética Intervencionista , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Complicações Pós-Operatórias/diagnóstico , Radiografia Intervencionista , Fusão Vertebral/instrumentação , Substitutos Ósseos , Discotomia/métodos , Desenho de Equipamento , Humanos , Imageamento por Ressonância Magnética , Fusão Vertebral/métodos , Tomografia Computadorizada por Raios X
19.
J Radiol Case Rep ; 5(4): 10-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22470786

RESUMO

Intracranial dermoid cysts are rare tumors derived from ectopic epithelial cells. They are slow-growing benign entities, but can cause significant morbidity through compression of neurovascular structures and, rarely, rupture into the subarachnoid space. We present a rare case of a spontaneously ruptured intracranial dermoid cyst presenting as new onset seizures due to chemical meningitis caused by dissemination of fat droplets.


Assuntos
Cisto Dermoide/patologia , Convulsões/etiologia , Adulto , Cisto Dermoide/complicações , Cisto Dermoide/diagnóstico por imagem , Humanos , Lipídeos , Imageamento por Ressonância Magnética , Masculino , Meningite/complicações , Ruptura Espontânea , Espaço Subaracnóideo/diagnóstico por imagem , Espaço Subaracnóideo/patologia , Tomografia Computadorizada por Raios X , Adulto Jovem
20.
J Neurosurg Spine ; 13(3): 371-80, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20809733

RESUMO

OBJECT: The aim of this retrospective study was to evaluate the predictive value of diffusion tensor (DT) imaging with respect to resectability of intramedullary spinal cord tumors and to determine the concordance of this method with intraoperative surgical findings. METHODS: Diffusion tensor imaging was performed in 14 patients with intramedullary lesions of the spinal cord at different levels using a 3-T magnet. Routine MR imaging scans were also obtained, including unenhanced and enhanced T1-weighted images and T2-weighted images. Patients were classified according to the fiber course with respect to the lesion and their lesions were rated as resectable or nonresectable. These results were compared with the surgical findings (existence vs absence of cleavage plane). The interrater reliability was calculated using the kappa coefficient of Cohen. RESULTS: Of the 14 patients (7 male, 7 female; mean age 49.2 +/- 15.5 years), 13 had tumors (8 ependymomas, 2 lymphomas, and 3 astrocytoma). One lesion was proven to be a multiple sclerosis plaque during further diagnostic workup. The lesions could be classified into 3 types according to the fiber course. In Type 1 (5 cases) fibers did not pass through the solid lesion. In Type 2 (3 cases) some fibers crossed the lesion, but most of the lesion volume did not contain fibers. In Type 3 (6 cases) the fibers were completely encased by tumor. Based on these results, 6 tumors were considered resectable, 7 were not. During surgery, 7 tumors showed a good cleavage plane, 6 did not. The interrater reliability (Cohen kappa) was calculated as 0.83 (p < 0.003), which is considered to represent substantial agreement. The mean duration of follow-up was 12.0 +/- 2.9. The median McCormick grade at the end of follow-up was II. CONCLUSIONS: These preliminary data suggest that DT imaging in patients with spinal cord tumors is capable of predicting the resectability of the lesion. A further prospective study is needed to confirm these results and any effect on patient outcome.


Assuntos
Imagem de Tensor de Difusão/métodos , Neoplasias da Medula Espinal/patologia , Neoplasias da Medula Espinal/cirurgia , Terapia Assistida por Computador/métodos , Astrocitoma/patologia , Astrocitoma/cirurgia , Imagem de Tensor de Difusão/instrumentação , Ependimoma/patologia , Ependimoma/cirurgia , Feminino , Seguimentos , Humanos , Período Intraoperatório , Linfoma/patologia , Linfoma/cirurgia , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Esclerose Múltipla/cirurgia , Vias Neurais/patologia , Variações Dependentes do Observador , Estudos Retrospectivos , Medula Espinal/patologia , Medula Espinal/cirurgia , Resultado do Tratamento
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