Nitamar Abdala

Radiographic and clinical evaluation of cage subsidence after stand-alone lateral interbody fusion

OBJECT Indirect decompression of the neural structures through interbody distraction and fusion in the lumbar spine is feasible, but cage subsidence may limit maintenance of the initial decompression. The influence of interbody cage size on subsidence and symptoms in minimally invasive lateral interbody fusion is heretofore unreported. The authors report the rate of cage subsidence after lateral interbody fusion, examine the clinical effects, and present a subsidence classification scale. METHODS The study was performed as an institutional review board-approved prospective, nonrandomized, comparative, single-center radiographic and clinical evaluation. Stand-alone short-segment (1- or 2-level) lateral lumbar interbody fusion was investigated with 12 months of postoperative follow-up. Two groups were compared. Forty-six patients underwent treatment at 61 lumbar levels with standard interbody cages (18 mm anterior/posterior dimension), and 28 patients underwent treatment at 37 lumbar levels with wide cages (22 mm). Standing lateral radiographs were used to measure segmental lumbar lordosis, disc height, and rate of subsidence. Subsidence was classified using the following scale: Grade 0, 0%-24% loss of postoperative disc height; Grade I, 25%-49%; Grade II, 50%-74%; and Grade III, 75%-100%. Fusion status was assessed on CT scanning, and pain and disability were assessed using the visual analog scale and Oswestry Disability Index. Complications and reoperations were recorded. RESULTS Pain and disability improved similarly in both groups. While significant gains in segmental lumbar lordosis and disc height were observed overall, the standard group experienced less improvement due to the higher rate of interbody graft subsidence. A difference in the rate of subsidence between the groups was evident at 6 weeks (p = 0.027), 3 months (p = 0.042), and 12 months (p = 0.047). At 12 months, 70% in the standard group and 89% in the wide group had Grade 0 or I subsidence, and 30% in the standard group and 11% in wide group had Grade II or III subsidence. Subsidence was detected early (6 weeks), at which point it was correlated with transient clinical worsening, although progression of subsidence was not observed after the 6-week time point. Moreover, subsidence occurred predominantly (68%) in the inferior endplate. Fusion rate was not affected by cage dimension (p > 0.999) or by incidence of subsidence (p = 0.383). CONCLUSIONS Wider cages avoid subsidence and better restore segmental lordosis in stand-alone lateral interbody fusion. Cage subsidence is identified early in follow-up and can be accessed using the proposed classification scale.

Stand-alone lateral interbody fusion for the treatment of low-grade degenerative spondylolisthesis.

The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10 y/o; 73.1% female; 27.4 ± 3.4 BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis.

White matter spectroscopy in neuromyelitis optica: a case control study.

BackgroundNaa/Cr ratio in normal appearing white matter (NAWM) of patients with multiple sclerosis (MS) is altered beyond plaques, suggesting early axonal loss, and correlates to clinical disability. Brain lesions not typical of MS have been described in Neuromyelitis optica (NMO), and correspond to brain aquaporin-4 channel sites, but the evaluation of Naa/Cr ratio in NAWM of patients with NMO and its association to the presence of brain lesions and clinical disability have not been described.ObjectivesTo evaluate the Naa/Cr of normal appearing white matter (NAWM) in 16 patients with NMO compared to healthy controls.MethodsWe performed brain magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of 16 patients with NMO and compared to age matched healthy controls.ResultsNAWM Naa/Cr did not show statistical difference among patients and controls, neither between patients that had normal brain MRI and atypical brain lesions.ConclusionNAWM was found to have a normal Naa/Cr in patients with NMO, reinforcing the concept that the white matter is not primarily affected in this disease.

Neuromyelitis optica: brain abnormalities in a Brazilian cohort

Neuromyelitis optica (NMO) is a demyelinating disease consisting of relapsing-remitting optic neuritis and myelitis with a more severe course than Multiple Sclerosis. Recently, it has been shown that almost 50% of patients with NMO can have brain magnetic resonance imaging (MRI) abnormalities. We report on six Brazilian patients with NMO, fulfilling the 1999 Wingerchuck criteria for this disease, with abnormal brain MRI and discuss their clinical and radiological features.

New Trends in Diffusion-Weighted Magnetic Resonance Imaging as a Tool in Differentiation of Serous Cystadenoma and Mucinous Cystic Tumor: A Prospective Study

Background/Aims: Pancreatic cystic lesions are increasingly being recognized. Magnetic resonance imaging (MRI) is the method that brings the greatest amount of information about the morphologic features of pancreatic cystic lesions. To establish if diffusion-weighted MRI (DW-MRI) can be used as a tool to differentiate mucinous from nonmucinous lesions. Methods: Fifty-six patients with pancreatic cystic lesions (benign, n = 46; malignant, n = 10) were prospectively evaluated with DW-MRI in order to differentiate mucinous from nonmucinous lesions. Final diagnosis was obtained by follow-up (n = 31), surgery (n = 16) or endoscopic ultrasound-guided fine needle aspiration (n = 9). Serous cystadenoma was identified in 32 (57%) patients. Results: The threshold value established for the differentiation of mucinous from nonmucinous lesions was 2,230.06 s/mm2 for ADC of 700. DWI-MRI behavior between mucinous and nonmucinous groups revealed sensitivity, specificity, positive predictive value, negative predictive value and accuracy to be 80, 98, 92, 93 and 93%, respectively (p < 0.01, power of sample = 1.0). In the comparison of the diffusion behavior between mucinous (n = 13) and serous (n = 32) lesions, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100, 97, 92, 100 and 98%, respectively (p < 0.01, power of sample = 1.0). The results of endoscopic ultrasound-guided fine needle aspiration were similar to those of DW-MRI. Conclusions: DW-MRI can be included as part of the array of tools to differentiate mucinous from nonmucinous lesions and can help in the management of pancreatic cystic lesions.

Clinical and radiographic study of orofacial alterations in patients with systemic sclerosis

Systemic sclerosis (SS) is an autoimmune disease with great repercussions on the hard and soft tissues of the orofacial region. The aim of this study was to investigate the relationship between mandibular osteolysis and mouth opening measurements, duration of disease and presence/absence of teeth. Twenty-five subjects were selected: 15 diagnosed with systemic sclerosis and 10 healthy controls. The SS patients were grouped according to the presence (group I) or absence (group II) of mandibular osteolysis. The healthy subjects served as the control group (III). All of them underwent panoramic radiography on Ortophos equipment (Siemens) and were clinically examined, with mouth opening measurement. We observed that group I had a longer duration of the disease than group II (p = 0.003). Groups I and II presented the same mean mouth opening. There was an increasing correlation between mouth opening and duration of the disease in group I (p = 0.095), but this was not observed in group II (p = 0.596). There was no correlation between presence/absence of teeth and osteolysis (p > 0.999), or between presence/absence of teeth and side of osteolysis (p = 0.143). We could conclude that osteolysis seemed to develop in patients with a longer duration of the disease, but did not modify the degree of mouth opening in relation to patients without osteolysis, and the presence/absence of teeth was not significant. On the other hand, in the osteolysis cases, the longer the duration of the disease, the greater the opening of the mouth.

Diffusion tensor imaging of the cervical spinal cord of patients with Neuromyelitis Optica.

BACKGROUND Previous studies have demonstrated a correlation between Expanded Disability Status Scale (EDSS) and Diffusion Tensor Imaging (DTI) metrics, but the conclusions were based on evaluations of the entire cervical spinal cord. OBJECTIVES The purpose of this study was to quantify the FA and MD values in the spinal cord of NMO patients, separating the lesion sites from the preserved sites, which has not been previously preformed. In addition, we attempted to identify a correlation with EDSS. METHODS DTI was performed in 11 NMO patients and 11 healthy individuals using a 1.5-T MRI scanner. We measured the FA and MD at ROIs positioned along the cervical spinal cord. The mean values of FA and MD at lesion, preserved and spinal cord sites were compared with those of a control group. We tested the correlations between the mean FA and MD with EDSS. RESULTS FA in NMO patients was significantly reduced in lesion sites (0.44 vs. 0.55, p=0.0046), preserved sites (0.46 vs. 0.55, p=0.0015), and all sites (0.45 vs 0.55, p=0.0013) while MD increased only in lesion sites (1.03×10(-3)mm(2)/s vs. 0.90×10(-3)mm(2)/s, p=0.009). The FA demonstrated the best correlation with EDSS (r=-0.7603, p=0.0086), particularly at lesion sites. CONCLUSIONS The results reinforce the importance of the FA index and confirm the hypothesis that NMO is a diffuse disease.

BASAL ENCEPHALOCELE ASSOCIATED WITH MORNING GLORY SYNDROME : Case report

The basal encephaloceles refer to rare entities and they correspond to herniation of brain tissue through defects of skull along the cribiform plate or the sphenoid bone. A rare morning glory syndrome, with characteristic retinal defect has been reported in association with basal encephaloceles. Hypophysis hormonal deficiencies may occur. We accounted for a pituitary dwarfism with delayed diagnosed transsphenoidal encephalocele associated with morning glory syndrome, showing the alterations found in retinography, computed tomography and magnetic resonance imaging.

Temporal pole signal abnormality on MR imaging in temporal lobe epilepsy with hippocampal sclerosis: a fluid-attenuated inversion-recovery study

OBJECTIVE To determine the frequency and regional involvement of temporal pole signal abnormality (TPA) in patients with hippocampal sclerosis (HS) using fluid-attenuated inversion-recovery (FLAIR) MR imaging, and to correlate this feature with history. METHOD Coronal FLAIR images of the temporal pole were assessed in 120 patients with HS and in 30 normal subjects, to evaluate gray-white matter demarcation. RESULTS Ninety (75%) of 120 patients had associated TPA. The HS side made difference regarding the presence of TPA, with a left side prevalence (p=0.04, chi2 test). The anteromedial zone of temporal pole was affected in 27 (30%) out of 90 patients. In 63 (70%) patients the lateral zone were also affected. Patients with TPA were younger at seizure onset (p=0.018), but without association with duration of epilepsy. CONCLUSION Our FLAIR study show temporal pole signal abnormality in 3/4 of patients with HS, mainly seen on the anteromedial region, with a larger prevalence when the left hippocampus was involved.

Imaging procedures in adrenal pathology

Imaging plays a vital role in the evaluation of adrenal pathology. The most widely used modalities are computed tomography and magnetic resonance imaging. Alone or in conjunction with appropriate clinical and biochemical data, imaging can provide specific diagnoses that preclude the need for tissue sampling. This article reviews imaging features of normal and diseased adrenals, from both benign and malignant causes.