Adult hemiconvulsive hemiatrophy syndrome: a novel clinicoradiologic disorder in adults

The association of focal motor seizures with cerebral hemiatrophy is a recognised rare paediatric syndrome known as 'hemiconvulsion, hemiatrophy and epilepsy' (HHE). To date, HHE has not been reported in adults. We present four adult patients with striking similarities to HHE, following alcohol withdrawal in chronic alcoholics. We document the imaging findings in the acute and subacute phases, discuss the underlying mechanisms and present a hypothesis regarding the pathophysiology.

Malpractice Litigation Related to Diagnosis and Treatment of Intracranial Aneurysms

BACKGROUND AND PURPOSE

Approaches to management of intracranial aneurysms are inconsistent, in part due to apprehension relating to potential malpractice claims. The purpose of this article was to review the causes of action underlying medical malpractice lawsuits related to the diagnosis and management of intracranial aneurysms and to identify the factors associated and their outcomes.

MATERIALS AND METHODS

We consulted 2 large legal databases in the United States to search for cases in which there were jury awards and settlements related to the diagnosis and management of patients with intracranial aneurysms in the United States. Files were screened to include only those cases in which the cause of action involved negligence in the diagnosis and management of a patient with an intracranial aneurysm.

RESULTS

Between 2000 and 2020, two hundred eighty-seven published case summaries were identified, of which 133 were eligible for inclusion in the analysis. Radiologists constituted 16% of 159 physicians sued in these lawsuits. Failure to diagnose was the most common medical malpractice claim referenced (100/133 cases), with the most common subgroups being "failure to include cerebral aneurysm as a differential and thus perform adequate work-up" (30 cases), and "failure to correctly interpret aneurysm evidence on CT or MR imaging" (16 cases). Only 6 of these 16 cases were adjudicated at trial, with 2 decided in favor of the plaintiff (awarded $4,000,000 and $43,000,000, respectively).

CONCLUSIONS

Incorrect interpretation of imaging is relatively infrequent as a cause of malpractice litigation compared with failure to diagnose aneurysms in the clinical setting by neurosurgeons, emergency physicians, and primary care providers.

Inflammation, Hippocampal Volume, and Therapeutic Outcome following Electroconvulsive Therapy in Depressive Patients: A Pilot Study

INTRODUCTION

Electroconvulsive therapy (ECT) influences the concentration of peripheral inflammatory markers, such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In which way this immune effect contributes to the impact of ECT on the central nervous system in depression remains unknown.

OBJECTIVE

The aim of this study was to examine whether the hippocampal volumetric increase in depressed patients treated with ECT is related to changes in peripheral IL-6 and TNF-α levels.

METHODS

IL-6 and TNF-α plasma levels were measured in 62 patients 1 week before and after an acute course of ECT. Hippocampal volumes were analyzed in a magnetic resonance imaging (MRI) subsample of 13 patients at the same time points.

RESULTS

A significant decrease in IL-6 levels was observed in the total sample and a significant increase in hippocampal volume in the MRI subsample. The reduction of peripheral IL-6 correlated with an increase in total hippocampal volume. A more limited decrease of TNF-α correlated with a more limited increase of both the total and left hippocampus volumes.

CONCLUSION

This pilot study is the first to highlight the link between peripheral immune changes and hippocampal volume increase following ECT. Further research is required to conclude whether ECT indeed exerts its central effect on the brain via changes of peripheral inflammatory markers.

The basal ganglia: A central hub for the psychomotor effects of electroconvulsive therapy

BACKGROUND

Electroconvulsive therapy (ECT) is the most effective biological treatment for depression. Aside the well-known therapeutic effect on mood symptoms, it has also a unique positive impact on psychomotor agitation and retardation, which are core symptoms of depression. The neurobiology behind these effects, however, remains unclear. The basal ganglia are proposed to be important regions in the pathogenesis of psychomotor symptoms in depression. Since ECT can trigger neuroplasticity in these subcortical nuclei, we speculate that ECT-induced volumetric changes of the basal ganglia will positively influence psychomotor symptoms.

METHODS

Psychomotor symptoms were analyzed in 17 patients with severe depression before and after an acute ECT course using a CORE assessment of the retardation, agitation, and non-interaction domains. The volumes of the caudate, putamen, pallidum, and accumbens regions were determined using magnetic resonance imaging one week before and after ECT.

RESULTS

Psychomotor functions had improved significantly after ECT and significant volume increases were found for the accumbens region, the putamen, and pallidum. The volume increase of the nucleus accumbens correlated with an improvement of psychomotor retardation, while the volume increase of the pallidum correlated negatively with an improvement of the agitation subscore.

CONCLUSION

Our findings support the notion of an association between the impact of ECT on depression-related psychomotor symptoms and volume increases of the accumbens region and pallidum, pointing to the importance of the basal ganglia in the therapeutic effect of ECT on psychomotor functioning.

Tolerogenic dendritic cell-based treatment for multiple sclerosis (MS): a harmonised study protocol for two phase I clinical trials comparing intradermal and intranodal cell administration

INTRODUCTION

Based on the advances in the treatment of multiple sclerosis (MS), currently available disease-modifying treatments (DMT) have positively influenced the disease course of MS. However, the efficacy of DMT is highly variable and increasing treatment efficacy comes with a more severe risk profile. Hence, the unmet need for safer and more selective treatments remains. Specifically restoring immune tolerance towards myelin antigens may provide an attractive alternative. In this respect, antigen-specific tolerisation with autologous tolerogenic dendritic cells (tolDC) is a promising approach.

METHODS AND ANALYSIS

Here, we will evaluate the clinical use of tolDC in a well-defined population of MS patients in two phase I clinical trials. In doing so, we aim to compare two ways of tolDC administration, namely intradermal and intranodal. The cells will be injected at consecutive intervals in three cohorts receiving incremental doses of tolDC, according to a best-of-five design. The primary objective is to assess the safety and feasibility of tolDC administration. For safety, the number of adverse events including MRI and clinical outcomes will be assessed. For feasibility, successful production of tolDC will be determined. Secondary endpoints include clinical and MRI outcome measures. The patients' immune profile will be assessed to find presumptive evidence for a tolerogenic effect in vivo.

ETHICS AND DISSEMINATION

Ethics approval was obtained for the two phase I clinical trials. The results of the trials will be disseminated in a peer-reviewed journal, at scientific conferences and to patient associations.

TRIAL REGISTRATION NUMBERS

NCT02618902 and NCT02903537; EudraCT numbers: 2015-002975-16 and 2015-003541-26.

Follow-up brain imaging of 37 children with congenital Zika syndrome: case series study

Objective To compare initial brain computed tomography (CT) scans with follow-up CT scans at one year in children with congenital Zika syndrome, focusing on cerebral calcifications.Design Case series study.Setting Barão de Lucena Hospital, Pernambuco state, Brazil.Participants 37 children with probable or confirmed congenital Zika syndrome during the microcephaly outbreak in 2015 who underwent brain CT shortly after birth and at one year follow-up.Main outcome measure Differences in cerebral calcification patterns between initial and follow-up scans.Results 37 children were evaluated. All presented cerebral calcifications on the initial scan, predominantly at cortical-white matter junction. At follow-up the calcifications had diminished in number, size, or density, or a combination in 34 of the children (92%, 95% confidence interval 79% to 97%), were no longer visible in one child, and remained unchanged in two children. No child showed an increase in calcifications. The calcifications at the cortical-white matter junction which were no longer visible at follow-up occurred predominately in the parietal and occipital lobes. These imaging changes were not associated with any clear clinical improvements.Conclusion The detection of cerebral calcifications should not be considered a major criterion for late diagnosis of congenital Zika syndrome, nor should the absence of calcifications be used to exclude the diagnosis.

Semicircular Canal Fibrosis as a Biomarker for Lateral Semicircular Canal Function Loss

Background and purpose

Radiological abnormalities at the level of the semicircular canals are frequently observed without known correlation to a pathologic condition or function. They include narrowing or sclerosis on computed tomography (CT) and narrowing or signal loss on T2-weighted magnetic resonance imaging (MRI). Our hypothesis was that these radiological abnormalities at the level of the semicircular canals reflect an aspecific but advanced stage of vestibular decay.

Materials and methods

Retrospective study in 35 consecutive patients with bilateral profound deafness eligible for cochlear implantation. Electronystagmography, CT, and MRI were performed as part of evaluation for cochlear implant candidacy.

Results

In our population, 31.4% had a bilateral lateral semicircular canal function loss, while 11.4% had a unilateral lateral semicircular canal function loss. CT-scan abnormalities did not correlate to lateral semicircular canal function loss at a statistically significant level. However, abnormalities observed on MRI correlated significantly with ipsilateral lateral semicircular canal function loss. This statistically significant difference was present not only if abnormalities were observed in at least one of the semicircular canals but also if we studied the posterior, superior, and lateral semicircular canals separately.

Conclusion

Semicircular canal abnormalities on T2-weighted MRI (including narrowing and/or signal loss in one or more semicircular canals) are correlated to lateral semicircular canal function loss.

The optic nerve sheath hemorrhage is a non-specific finding in cases of suspected child abuse

In young infants, the triad consisting of acute encephalopathy, retinal hemorrhages, and a subdural hematoma is a nonspecific finding. It has traumatic and non-traumatic etiologies. The triad may be found among a vast spectrum of natural diseases. Optic nerve sheath hemorrhage in infants is typically detected at autopsy. It is a nonspecific finding that can be found in traumatic and non-traumatic etiologies. Neither the triad nor the ONSH are pathognomonic for an abusive head injury. Opposite to the triad, the spectrum of non-traumatic etiologies of ONSH is limited. In infants ONSH rarely occurs in spontaneous subarachnoidal hemorrhage or in infectious conditions. Our results show that the clinical significance of the optic nerve sheath hemorrhage in the forensic work-up of fatal cases of alleged abusive head injury is its limited differential diagnosis. Only after careful differential diagnosis ONSH may contribute to the diagnosis of AHT. However, the main limitation of our study is the sampling bias, as the eyes are usually removed when abusive head trauma is suspected.

Encephalitis related to a H1N1 vaccination: case report and review of the literature

OBJECTIVES

To illustrate that acute, even dramatic, demyelination of the central nervous system and encephalitis can occur after viral, i.e., influenza A/H1N1 vaccination or infection.

PATIENTS AND METHODS

We describe a case of encephalitis/acute disseminated encephalomyelitis associated with vaccination against influenza A/H1N1 and review the available literature.

RESULTS

We report a case of a 26-year-old female who developed symptoms of acute encephalitis 5 days after vaccination against the pandemic 2009 A/H1N1 influenza. MRI of the brain showed confluent T2-hyperintense signal intensity changes in the deep white matter which further confirmed the diagnosis of encephalitis/acute disseminated encephalomyelitis. Despite therapy with immunoglobulins and corticosteroids, her persistent vegetative state continued. In light of the dramatic cause of this case, we reviewed all 21 other previously reported cases of central nervous system demyelination related to H1N1 vaccination and/or infection.

CONCLUSIONS

The available data suggest that even severe central nervous system demyelination i.e. acute encephalitis/disseminated encephalomyelitis and transverse myelitis may very rarely be associated with vaccination against novel influenza A/H1N1 or with A/H1N1 infection itself.

Delta-storage pool disease as a mimic of abusive head trauma in a 7-month-old baby: a case report

A seven-month-old baby was admitted to a hospital emergency department after collapsing suddenly while staying with his nanny. The baby displayed classic symptoms of shaken baby syndrome, including subdural haemorrhage, cytotoxic cerebral oedema, and bilateral retinal hemorrhages. Child protection services were informed, but both the parents and the nanny denied any involvement. In the subsequent weeks, the baby developed three other episodes of new subdural bleeding and a medico-legal investigation was started into the origin of the repeated subdural bleeding. Eventually, platelet aggregation tests and electron microscopy diagnosed a delta-storage pool disease; that is, a haemostatic disorder involving dense granules of the platelets. Initial minor blunt trauma may have resulted in subdural bleeding, while subsequent retinal haemorrhage could have been facilitated by the underlying haemostatic disorder. Delta-storage pool disease should be considered as a possible mimic of abusive head trauma similar to other rare conditions such as Menkes disease and type 1 glutaric aciduria.

Platelet-rich plasma in mono-segmental posterior lumbar interbody fusion

INTRODUCTION

The results of platelet-rich plasma (PRP) in spinal fusion applications are limited and controversial. Both beneficial and inhibitory effects have been shown. In this prospective randomised controlled trial, our objective was to assess both the clinical and radiological effect of PRP when added to autograft iliac crest bone in posterior lumbar interbody fusion.

METHODS AND MATERIALS

Forty patients were recruited for the study fulfilling strict entry requirements and were randomised with a 1:1 ratio. In each group, one patient was lost to follow-up. Thirtyeight patients completed the Visual Analogue Scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form 36 (SF-36) preoperatively and postoperatively at 3, 6, 12, and 24 months, respectively. CT-scans of the lumbar spine were taken at 3, 6, and 12 months. Posterior stabilisation was achieved with pedicle screws and interbody fusion was aimed at with carbon cages filled with autologous bone.

RESULTS

Baseline demographic data (age, sex, smoking history, preoperative outcome measures) showed no relevant difference between groups. For patients who received autograft only, the mean VAS improved by 4.0 points (p < 0.01), mean ODI improved by 32.1 points (p < 0.001), and mean SF-36 showed statistically significant improvement in each of the eight domains and in the physical (p < 0.001) and mental (p < 0.001) component summary measures. For patients who received autograft with PRP, the mean VAS improved by 4.92 points (p < 0.01), mean ODI improved by 30 points (p < 0.001), and mean SF-36 showed statistically significant improvement in six of the eight domains (p < 0.02) and in the physical (p = 0.016) and mental (p < 0.001) component summary measures. The improvement of the VAS score and the physical component summary score was more pronounced in patients who received autograft with PRP. These differences were, however, not statistically significant. CT-scans showed uneventful osseous healing in all but one patient with no difference between groups.

CONCLUSION

In this prospective randomised controlled clinical and radiological trial, adding PRP in posterior lumbar interbody fusion did not lead to a substantial improvement or deterioration when compared with autologous bone only. No inhibitory effect of PRP was observed on CT-scans. From a clinical and radiological point of view, the use of PRP seems to be justified in posterior lumbar interbody fusion surgery. From an economical point of view, the expense of using PRP cannot be justified until statistical significance can be reached in a larger study.

Microsurgical removal of Onyx HD-500 from an aneurysm for relief of brainstem compression. Case report

The authors report the successful removal of Onyx HD-500 from an aneurysm sac by means of ultrasonic aspiration. This 46-year-old woman presented with progressive spasms of her left arm and leg due to mass effect and compression on the right cerebral peduncle 5 years after endovascular treatment of an unruptured giant posterior communicating artery aneurysm with Onyx HD-500. No filling of the aneurysm was detected on angiography. The patient underwent a right pterional craniotomy and the aneurysm was opened to remove the Onyx mass. However, contrary to expectations, the aneurysm was still patent, filling with blood between the Onyx mass and the aneurysm wall. Under temporary clipping of the carotid artery, the Onyx mass within the aneurysm was removed in a piecemeal fashion using an ultrasonic aspirator and the aneurysm was then successfully clipped. The patient experienced significant improvement of the spasm after surgery. Angiography showed complete occlusion of the posterior communicating artery aneurysm. It is rarely necessary to remove embolization material such as Onyx HD-500, and little is known about the most appropriate surgical technique. This case report demonstrates that removal can be safely accomplished by means of ultrasonic aspiration.

Fasciola hepatica infection in a 65-year-old woman

Fascioliasis is an infectious disease caused by fasciola or liver fluke. Humans are accidental hosts to these flatworms. The World Health Organisation considers fascioliasis an important human parasitic disease. In Europe, Australia and Northern America, the disease is rare, but should have a high index of suspicion in patients who have lived in or travelled to endemic areas. Although it can be self-limiting, fascioliasis is associated with an increased risk of bile duct cancer. Before a clear-cut diagnosis is made using ELISA-based arrays, radiologic studies can provide the clinician with a number of suggestive features, thereby avoiding the need for liver biopsy or even surgery, which have nowadays become obsolete for the diagnosis of fascioliasis. We provide an overview of the major radiologic hallmarks and we demonstrate the role of iron-oxide enhanced MRI.

Progressive myoclonic epilepsy as an adult-onset manifestation of Leigh syndrome due to m.14487T>C

BACKGROUND

m.14487T>C, a missense mutation (p.M63V) affecting the ND6 subunit of complex I of the mitochondrial respiratory chain, has been reported in isolated childhood cases with Leigh syndrome (LS) and progressive dystonia. Adult-onset phenotypes have not been reported.

OBJECTIVES

To determine the clinical-neurological spectrum and associated mutation loads in an extended m.14487T>C family.

METHODS

A genotype-phenotype correlation study of a Belgian five-generation family with 12 affected family members segregating m.14487T>C was carried out. Clinical and mutation load data were available for nine family members. Biochemical analysis of the respiratory chain was performed in three muscle biopsies.

RESULTS

Heteroplasmic m.14487T>C levels (36-52% in leucocytes, 97-99% in muscle) were found in patients with progressive myoclonic epilepsy (PME) and dystonia or progressive hypokinetic-rigid syndrome. Patients with infantile LS were homoplasmic (99-100% in leucocytes, 100% in muscle). We found lower mutation loads (between 8 and 35% in blood) in adult patients with clinical features including migraine with aura, Leber hereditary optic neuropathy, sensorineural hearing loss and diabetes mellitus type 2. Despite homoplasmic mutation loads, complex I catalytic activity was only moderately decreased in muscle tissue.

INTERPRETATION

m.14487T>C resulted in a broad spectrum of phenotypes in our family. Depending on the mutation load, it caused severe encephalopathies ranging from infantile LS to adult-onset PME with dystonia. This is the first report of PME as an important neurological manifestation of an isolated mitochondrial complex I defect.

Quantitative diffusion tensor imaging in amyotrophic lateral sclerosis: revisited

Voxel-based analyses (VBA) are increasingly being used to detect white matter abnormalities with diffusion tensor imaging (DTI) in different types of pathologies. However, the validity, specificity, and sensitivity of statistical inferences of group differences to a large extent depend on the quality of the spatial normalization of the DTI images. Using high-dimensional nonrigid coregistration techniques that are able to align both the spatial and orientational diffusion information and incorporate appropriate templates that contain this complete DT information may improve this quality. Alternatively, a hybrid technique such as tract-based spatial statistics (TBSS) may improve the reliability of the statistical results by generating voxel-wise statistics without the need for perfect image alignment and spatial smoothing. In this study, we have used (1) a coregistration algorithm that was optimized for coregistration of DTI data and (2) a population-based DTI atlas to reanalyze our previously published VBA, which compared the fractional anisotropy and mean diffusivity maps of patients with amyotrophic lateral sclerosis (ALS) with those of healthy controls. Additionally, we performed a complementary TBSS analysis to improve our understanding and interpretation of the VBA results. We demonstrate that, as the overall variance of the diffusion properties is lowered after normalizing the DTI data with such recently developed techniques (VBA using our own optimized high-dimensional nonrigid coregistration and TBSS), more reliable voxel-wise statistical results can be obtained than had previously been possible, with our VBA and TBSS yielding very similar results. This study provides support for the view of ALS as a multisystem disease, in which the entire frontotemporal lobe is implicated.

A common reference frame for describing rotation of the distal femur

The understanding of rotational alignment of the distal femur is essential in total knee replacement to ensure that there is correct placement of the femoral component. Many reference axes have been described, but there is still disagreement about their value and mutual angular relationship. Our aim was to validate a geometrically-defined reference axis against which the surface-derived axes could be compared in the axial plane. A total of 12 cadaver specimens underwent CT after rigid fixation of optical tracking devices to the femur and the tibia. Three-dimensional reconstructions were made to determine the anatomical surface points and geometrical references. The spatial relationships between the femur and tibia in full extension and in 90° of flexion were examined by an optical infrared tracking system.

After co-ordinate transformation of the described anatomical points and geometrical references, the projection of the relevant axes in the axial plane of the femur were mathematically achieved. Inter- and intra-observer variability in the three-dimensional CT reconstructions revealed angular errors ranging from 0.16° to 1.15° for all axes except for the trochlear axis which had an interobserver error of 2°. With the knees in full extension, the femoral transverse axis, connecting the centres of the best matching spheres of the femoral condyles, almost coincided with the tibial transverse axis (mean difference −0.8°, sd 2.05). At 90° of flexion, this femoral transverse axis was orthogonal to the tibial mechanical axis (mean difference −0.77°, sd 4.08). Of all the surface-derived axes, the surgical transepicondylar axis had the closest relationship to the femoral transverse axis after projection on to the axial plane of the femur (mean difference 0.21°, sd 1.77). The posterior condylar line was the most consistent axis (range −2.96° to −0.28°, sd 0.77) and the trochlear anteroposterior axis the least consistent axis (range −10.62° to +11.67°, sd 6.12). The orientation of both the posterior condylar line and the trochlear anteroposterior axis (p = 0.001) showed a trend towards internal rotation with valgus coronal alignment.

Hypoplasia of L5 and wedging and pseudospondylolisthesis in patients with spondylolysis: study with MR imaging

BACKGROUND AND PURPOSE

The association between L5 hypoplasia and bilateral spondylolysis was described earlier on conventional radiographs of the lumbar spine. The purpose of this study was to describe the findings on MR imaging in patients with hypoplasia of L5 and to correlate these findings with the presence of bilateral spondylolysis of L5.

MATERIAL AND METHODS

We studied the MR images of 22 patients with hypoplasia and posterior wedging of L5 and with bilateral spondylolysis at L5. The anteroposterior diameter of L4, L5, and S1 were measured and compared. The degree of posterior wedging of L5 was calculated. The degree of anterolisthesis was determined. The intervertebral disks of L4-L5 and L5-S1 were studied.

RESULTS

The mean difference between the anteroposterior diameter of L4 and L5 was 3.0 mm, or 8.8% shortening of L5 compared with L4. The mean difference between the anteroposterior diameter of L5 and S1 was 4.4 mm, or 12.3% shortening of L5 compared with S1. The mean percentage posterior wedging was 24.7%. In 13 patients, there was no anterior vertebral slipping. True anterolisthesis grade I was seen in 5 patients and anterolisthesis grade II in 4 patients. Diskarthrosis with disk dehydration of L4-L5 was seen in 20 of the 22 patients.

CONCLUSIONS

It is confirmed that hypoplasia of L5 can simulate anterolisthesis. Hypoplasia of the vertebral body of L5 can predict the presence of bilateral spondylolysis.

Management of cystic pancreatic masses

This paper presents our experience on the characterization of cystic pancreatic lesions using CT and MRI. First of all, true cystic pancreatic neoplasms should be differentiated from pseudocysts. Noninvasive characterization of cystic pancreatic neoplasms continues to rely principally on CT and MRI. Despite the presence of classic radiological characteristics of various cystic pancreatic neoplasms, these lesions continue to be problematic for the radiologist. They are most frequently incidental findings that are not related to the reason for imaging the patients in whom they are discovered. The radiological and clinical challenges are to determine the benign or malignant nature of the lesion and its potential resectability. The heterogeneity among cystic lesions and overlap in imaging characteristics should cause radiologists to approach the specific characterization of cystic pancreatic masses with a substantial degree of humility. Recommending an appropriate management approach based on imaging findings, in conjunction with clinical information and clinical consultation, may therefore be more important than attempting to assign a specific diagnosis to a cystic pancreatic lesion.

Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.

Multiscale white matter fiber tract coregistration: a new feature-based approach to align diffusion tensor data

In this paper an automatic multiscale feature-based rigid-body coregistration technique for diffusion tensor imaging (DTI) based on the local curvature kappa and torsion tau of the white matter (WM) fiber pathways is presented. As a similarity measure, the mean squared difference (MSD) of corresponding fiber pathways in (kappa, tau)-space is chosen. After the MSD is minimized along the arc length of the curve, principal component analysis is applied to calculate the transformation parameters. In addition, a scale-space representation of the space curves is incorporated, resulting in a multiscale robust coregistration technique. This fully automatic technique inherently allows one to apply region of interest (ROI) coregistration, and is adequate for performing both global and local transformations. Simulations were performed on synthetic DT data to evaluate the coregistration accuracy and precision. An in vivo coregistration example is presented and compared with a voxel-based coregistration approach, demonstrating the feasibility and advantages of the proposed technique to align DT data of the human brain.

Long-term results of primary stenting for long and complex iliac artery occlusions

OBJECTIVES

To evaluate the long-term results of recanalization with primary stenting for long and complex iliac artery occlusions.

DESIGN

Retrospective non-randomized study.

METHODS

Between 1996 and 2004, 38 patients underwent recanalization of an occluded iliac artery with subsequent stenting for TASC B lesions in 12 patients, TASC C in 10 and TASC D in 16. Thirty-one patients had Fontaine stage 2 B, four patients had stage 3 and one patient had stage 4. Two patients (5.4%) presented with acute ischemia and received trombolysis before recanalization. Patency results were calculated using Kaplan and Meier analysis. The mean follow-up was 26 months.

RESULTS

Technical success was 97.4%. Thirty-day mortality was 2.7%. The primary patency rate was 94%, 89% and 77% at 1, 3 and 5 years respectively. Three re-occlusions (8.1%) and one restenosis (2.7%) were observed during follow-up. The secondary patency (SP) rate was 100%, 94% and 94% after 1, 2 and 3 years. Fifteen patients underwent an associated procedure. A kissing stent procedure in three patients, a contralateral PTA of an iliac stenosis in 8, a femoro-femoral bypass in 2, a femoropopliteal bypass in 1 and an femoral endarterectomy in 2. The procedure related complication rate was 5.4%.

CONCLUSION

Long-term results of iliac recanalization are excellent without major complications if the procedure is technically successful. The endovascular procedure can be an alternative to an iliofemoral or aortobifemoral bypass in a high risk population.

Posterior semicircular canal dehiscence: value of VEMP and multidetector CT

OBJECTIVE

To illustrate that posterior semicircular canal dehiscence can present similarly to superior semicircular canal dehiscence.

CASE STUDY

The symptomatology initially presented as probable Menière's disease evolving into a mixed conductive hearing loss with a Carhart notch-type perceptive component suggestive of otosclerosis-type stapes fixation. A small hole stapedotomy resulted in a dead ear and a horizontal semicircular canal hypofunction. Recurrent incapacitating vertigo attacks developed. Vestibular evoked myogenic potential (VEMP) testing demonstrated intact vestibulocollic reflexes. Additional evaluation with high resolution multidetector computed tomography (MDCT) of the temporal bone showed a dehiscence of the left posterior semicircular canal.

CONCLUSIONS

Besides superior semicircular canal dehiscence, posterior semicircular canal dehiscence has to be included in the differential diagnosis of atypical Menière's disease and/or low tone conductive hearing loss. The value of performing MDCT before otosclerosis-type surgery is stressed. VEMP might contribute to establishing the differential diagnosis.

Inadvertent intrathecal use of ionic contrast agent

Intrathecal administration of ionic contrast media may cause severe and fatal neurotoxic reactions due to their hyperosmolarity and ionic nature. They are therefore strictly contraindicated for all radiologic applications involving the central nervous system (e.g., myelography). We present a case in which ioxitalamate was accidentally injected intrathecally. The patient recovered completely due to a combination of the different therapeutic options reported in the literature, including early mechanical ventilation and neuromuscular paralysis, aggressive control of seizures, elevation of head and trunk to prevent cephalad migration of contrast, steroids, cerebrospinal fluid drainage and lavage and prophylactic antibiotics.

Prediction of malignancy in solitary thyroid nodules: value of preoperative explorations

The thyroid nodule is a topic in clinical medicine which remains controversial because any thyroid disease can virtually turn up a thyroid nodule. The reliability of the diagnostic techniques for making the distinction between a benign and a malignant lesion varies. The various techniques for the assessment of a solitary nonfunctional thyroid nodule are described and their comparative values in establishing the nature of the nodule, identifying patients with low likelihood of malignancy--making it possible to defer surgery or to avoid it altogether--are analyzed. According to the results and for several reasons, controversy over the best approach of solitary cold nodule management can remain. We propose an alternative approach and provide a personal guideline for the use of these tests.

Nerve sheath tumors: evaluation with CT and MR imaging

Tumors of nerves are classified into benign (schwannoma and neurofibroma) and malignant nerve sheath tumors. Schwannomas almost always occur as solitary lesions, whereas neurofibromas may occur alone or in a greater number, especially in patients with the peripheral form of von Recklinghausen's disease. Benign nerve sheath tumors often present as asymptomatic, slowly growing soft tissue masses. Although malignant nerve sheath tumors are relatively rare, a sudden increase in the size of a lesion, in particular in a patient with neurofibromatosis, should raise the suspicion of malignant change. On computed tomography (CT) and magnetic resonance imaging (MR) a benign nerve sheath tumor usually appears as a well-defined, oval, spherical or fusiform mass with smooth borders and distinct outlines, located in the subcutaneous tissue or centered at the expected anatomic location of a nerve, with displacement of adjacent soft tissues. Generally nerve sheath tumors have a low density on unenhanced CT scans. On MR they are isointense to muscle on T1-weighted images, whereas on T2-weighted images the signal intensity is high. Both on CT and MR the degree of contrast enhancement is moderate to marked and may be homogeneous or inhomogeneous. MR has become the method of choice for evaluating the anatomic location, contour, and relation of a nerve sheath tumor to adjacent neural, vascular, and muscular structures. The imaging criteria for malignant nerve sheath tumors are not specific enough to distinguish them from other malignant soft tissue tumors, so that neither CT nor MR can establish a definite diagnosis.

Consequences and complications of glycerol injection in the cavum of Meckel: a series of 120 consecutive injections

From 1983 to 1989, 120 injections of glycerol into the trigeminal ganglion were performed to treat facialgias of different origin. The subjective and objective consequences and complications are reviewed. Since this operation yielded most often mild, transient and well tolerated consequences and complications for the patient, we now propose this method as first choice for trigeminal neuralgia when there is no anamnestic or clinical evidence of damage to the trigeminal system.

Pulmonary haematoma caused by oral anticoagulant therapy. Report of a case

During a poorly controlled warfarin treatment, a 51-year-old man developed bleeding in various organs. He presented a pulmonary haematoma with the radiologic appearance of a pulmonary nodule. In the literature we found only one report of a pulmonary haematoma with a similar presentation caused by anticoagulant therapy.