The Management of Lower Extremity Multilevel Arterial Injuries: A 10-Year Experience

Background

Limb amputation due to lower extremity arterial injury is not uncommon and multilevel arterial injury is even more limb-threatening and easily missed with potentially devastating consequences. There is limited information on multilevel arterial injuries.

Purpose

We undertook a review of our experience to gain insight on multilevel arterial injury patterns associated with lower extremity trauma and to analyze the results of management of such injuries with a special focus on the influence of initial diagnosis on limb salvage.

Patients and Methods

Between August 2002 and September 2012, 38 patients with lower extremity multilevel arterial injuries were reviewed, retrospectively. The injury patterns and amputation rates associated with initial diagnosis or misdiagnosis were analyzed.

Results

According to their injury levels, three multilevel arterial injury patterns were seen in this series: arterial injuries with the involvement of femoral artery and popliteal artery (pattern A), femoral artery and anterior or (and) posterior artery (pattern B), and popliteal artery and anterior or (and) posterior artery (pattern C). The general missed diagnosis rate was 31.6%. Pattern B had a much higher missed diagnosis rate than the other two patterns. The missed diagnosis rate was significantly correlated with the amputation rates (Odds Ratio =10.7, 95% CI: 2.04-56.61). The definite diagnosis rate was only 14.8% using duplex ultrasonography examination.

Conclusions

Diagnosis of pattern B injury is more prone to be missed. DUS has low specificity in the detection of multilevel arterial injuries. Aggressive intraoperative exploration is considered to be valuable in the definitive diagnosis of highly suspected cases when other diagnostic tools are unavailable.     

Neonatal Mortality and Long-Term Outcome of Infants Born between 27 and 32 Weeks of Gestational Age in Breech Presentation: The EPIPAGE Cohort Study

Objective

To determine whether breech presentation is an independent risk factor for neonatal morbidity, mortality, or long-term neurologic morbidity in very preterm infants.

Design

Prospective population-based cohort.

Population

Singletons infants without congenital malformations born from 27 to 32 completed weeks of gestation enrolled in France in 1997 in the EPIPAGE cohort.

Methods

The neonatal and long-term follow-up outcomes of preterm infants were compared between those in breech presentation and those in vertex presentation. The relation of fetal presentation with neonatal mortality and neurodevelopmental outcomes was assessed using multiple logistic regression models.

Results

Among the 1518 infants alive at onset of labor included in this analysis (351 in breech presentation), 1392 were alive at discharge. Among those eligible to follow up and alive at 8 years, follow-up data were available for 1188 children. Neonatal mortality was significantly higher among breech than vertex infants (10.8% vs. 7.5%, P = 0.05). However the differences were not significant after controlling for potential confounders. Neonatal morbidity did not differ significantly according to fetal presentation. Severe cerebral palsy was less frequent in the group born in breech compared to vertex presentation but there was no difference after adjustment. There was no difference according to fetal presentation in cognitive deficiencies/learning disabilities or overall deficiencies.

Conclusion

Our data suggest that breech presentation is not an independent risk factor for neonatal mortality or long-term neurologic deficiencies among very preterm infants.     

Assessment of Brainstem Function with Auricular Branch of Vagus Nerve Stimulation in Parkinson’s Disease

Background

The efferent dorsal motor nucleus of the vagal nuclei complex may degenerate early in the course of Parkinson’s disease (PD), while efferent nucleus ambiguous, the principal source of parasympathetic vagal neurons innervating the heart, and afferent somatosensory nuclei remain intact.

Objective

To obtain neurophysiological evidence related to this pattern, we tested processing of afferent sensory information transmitted via the auricular branch of the vagus nerve (ABVN) which is known to be connected to autonomic regulation of cardiac rhythm.

Methods

In this cross-sectional observational study, we recorded (i) somatosensory evoked potentials (ABVN-SEP) and (ii) cutaneo-cardioautonomic response elicited by stimulation of the ABVN (modulation of heart-rate variability (HRV index; low frequency power, ln(LF), high frequency power, ln(HF); ln(LF/HF) ratio)) in 50 PD patients and 50 age and sex matched healthy controls. Additionally, auditory evoked potentials and trigeminal nerve SEP were assessed.

Results

Neither ABVN-SEP nor any of the other functional brainstem parameters differed between patients and controls. Although HRV index was decreased in PD patients, modulation of ln(LF/HF) by ABVN-stimulation, likely indicating cardiac parasympathetic activation, did not differ between both groups.

Conclusions

Findings do not point to prominent dysfunction of processing afferent information from ABVN and its connected parasympathetic cardiac pathway in PD. They are consistent with the known pattern of degeneration of the vagal nuclei complex of the brainstem.     

Determination of a Central Avascular Triangle within the Obturator Foramen: A Radioanatomic Study

Purpose

To map the vascular anatomy of the obturator foramen using fixed anatomic landmarks.

Method

Twenty obturator regions were dissected in 10 fresh female cadavers after vascular blue dye injection in five cadavers (50%). Furthermore, 104 obturator regions were reconstructed by angiotomodensitometry from 52 women under investigation for suspected arterial disease. The anatomy of the obturator region was mapped by measuring the distance of vascular structures from the middle of the two branches of the ischiopubic bone, which were used as fixed landmarks.

Results

The bifurcation of the obturator artery was at a mean (SD) distance of 30.0 mm (4.5) from the middle of the ischiopubic branch (MISP). The anterior branch of the obturator vessels was 15.2 mm (10.1) from the MISP. The posterior branch of the obturator vessels was 5.5 mm (4.0) and 23.6 mm (8.7) from the middle of the outer edge of the obturator foramen (MOE) and the MISP, respectively. Using 5° and 95° percentiles of these measurements we defined a central avascular triangle.

Conclusions

Our data show that, beyond inter-individual variations, a central triangular avascular area can be identified in the obturator foramen between the posterior and anterior obturator artery using fixed landmarks.     

Outcome after Reconstruction of the Proximal Tibia – Complications and Competing Risk Analysis

Background and Objectives

The proximal tibia (pT) is a common site for bone tumors. Improvements in imaging, chemotherapy and surgical technique made limb salvage surgery the treatment of choice. Yet, reconstructions of the pT have been associated with less favorable outcome compared to other parts of the extremities. The aim of this study was to evaluate the outcome of patients with a modular endoprosthetic reconstruction of the pT.

Methods

Eighty-one consecutive patients with an average age of 29 years underwent endoprosthetic reconstruction of the pT. Postoperative complications were categorized according to the ISOLS classification, and revision-free survival until first complication (any Type 1–5), soft tissue failure (Type 1), aseptic loosening (Type 2), structural failure (Type 3), infection (Type 4), and local tumor progression (Type 5) was estimated by using a Fine-Gray model for competing risk analyses for univariate and multivariable regression with Firth’s bias correction.

Results

A total of 45 patients (56%) had at least one complication. Cumulative incidence for complication Types 1 to 5 at 5 years with death and amputation as competing events revealed a risk of 41% for the first complication, 14% for Type 1, 16% for Type 2, 11% for Type 3, 17% for Type 4, and 1% for Type 5.

Conclusion

Despite inclusion of amputation and death as strong competing events, pT replacements are still associated with a high risk of postoperative failures. The results suggest that infection and soft tissue failures (Type 1 and 5) seem to depend from each other. Sufficient soft tissue reconstruction and closure allow better function and reduce the risk of infection as the most prominent complication. The use of a rotating hinge design has significantly reduced structural failures over time.     

Type D Personality Predicts Poor Medication Adherence in Chinese Patients with Type 2 Diabetes Mellitus: A Six-Month Follow-Up Study

Background

Type D personality and medication nonadherence have been shown to be associated with poor health outcomes. Type D personality is associated with poor medication adherence in patients with coronary artery disease, myocardial infarction, and heart failure. However, the relationship between type D personality and medication adherence in patients with Type 2 Diabetes Mellitus (T2DM) remains unknown. This study aims to examine whether type D personality was associated with medication adherence in patients with T2DM.

Design and Settings

A follow-up study was conducted in general hospital of the People''s Liberation Army in Beijing.

Methods

412 T2DM patients (205 females), who were recruited by circular systematic random sampling, provided demographic and baseline data about medical information and completed measures of Type D personality. Then, 330 patients went on to complete a self-report measure of medication adherence at the sixth month after baseline data collection. Chi-square test, t tests, and hierarchical multiple regression analyses were conducted, as needed.

Results

Patients with type D personality were significantly more likely to have poor medication adherence (p<0.001). Type D personality predicts poor medication adherence before and after controlling for covariates when it was analyzed as a categorical variable. However, the dimensional construct of type D personality was not associated with medication adherence when analyzed as a continuous variable.

Conclusion

Although, as a dimensional construct, type D personality may not reflect the components of the personality associated with poor medication adherence in patients with T2DM, screening for type D personality may help to identify those who are at higher risk of poor medication adherence. Interventions, aiming to improve medication adherence, should be launched for these high-risk patients.     

The Association of Elastin Gene Variants with Two Angiographic Subtypes of Polypoidal Choroidal Vasculopathy

Objective

To compare the association of elastin (ELN) gene variants between two different angiographic phenotypes of polypoidal choroidal vasculopathy (PCV).

Methods

We included 411 treatment-naïve PCV patients and 350 controls in the present study. PCV was classified into two phenotypes (152 Type 1 and 259 Type 2) according to the presence or absence of feeding vessels found in indocyanine-green angiography. Single nucleotide polymorphisms (SNPs) in the ELN region including rs868005, rs884843, rs2301995, rs13239907 and rs2856728 were genotyped using TaqMan Genotyping Assays.

Results

In the allelic association analyses, rs868005 showed the strongest association with Type 2 PCV (allelic odds ratio 1.56; p = 7.4x10^-6), while no SNP was significantly associated with Type 1 PCV. Genotype association analyses revealed the significant association of rs868005 with Type 2 PCV in log additive model and predominant model (odds ratio 1.75; p = 1.5x10^-6 and odds ratio 1.60; p = 0.0044, respectively), but not with Type 1 PCV. These findings were further corroborated by another control group in the literature.

Conclusions

There may be significantly different associations in genetic variants of elastin between two angiographic phenotypes of PCV.     

Task Type Affects Location of Language-Positive Cortical Regions by Repetitive Navigated Transcranial Magnetic Stimulation Mapping

Objectives

Recent repetitive TMS (rTMS) mapping protocols for language mapping revealed deficits of this method, mainly in posterior brain regions. Therefore this study analyzed the impact of different language tasks on the localization of language-positive brain regions and compared their effectiveness, especially with regard to posterior brain regions.

Methods

Nineteen healthy, right-handed subjects performed object naming, pseudoword reading, verb generation, and action naming during rTMS language mapping of the left hemisphere. Synchronically, 5 Hz/10 pulses were applied with a 0 ms delay

Results

The object naming task evoked the highest error rate (14%), followed by verb generation (13%) and action naming (11%). The latter revealed more errors in posterior than in anterior areas. Pseudoword reading barely generated errors, except for phonological paraphasias.

Conclusions

In general, among the evaluated language tasks, object naming is the most discriminative task to detect language-positive regions via rTMS. However, other tasks might be used for more specific questions.     

Contralateral Noise Stimulation Delays P300 Latency in School-Aged Children

Background and Objective

The auditory cortex modulates auditory afferents through the olivocochlear system, which innervates the outer hair cells and the afferent neurons under the inner hair cells in the cochlea. Most of the studies that investigated the efferent activity in humans focused on evaluating the suppression of the otoacoustic emissions by stimulating the contralateral ear with noise, which assesses the activation of the medial olivocochlear bundle. The neurophysiology and the mechanisms involving efferent activity on higher regions of the auditory pathway, however, are still unknown. Also, the lack of studies investigating the effects of noise on human auditory cortex, especially in peadiatric population, points to the need for recording the late auditory potentials in noise conditions. Assessing the auditory efferents in schoolaged children is highly important due to some of its attributed functions such as selective attention and signal detection in noise, which are important abilities related to the development of language and academic skills. For this reason, the aim of the present study was to evaluate the effects of noise on P300 responses of children with normal hearing.

Methods

P300 was recorded in 27 children aged from 8 to 14 years with normal hearing in two conditions: with and whitout contralateral white noise stimulation.

Results

P300 latencies were significantly longer at the presence of contralateral noise. No significant changes were observed for the amplitude values.

Conclusion

Contralateral white noise stimulation delayed P300 latency in a group of school-aged children with normal hearing. These results suggest a possible influence of the medial olivocochlear activation on P300 responses under noise condition.     

Quantitative Analysis of Respiration-Related Movement for Abdominal Artery in Multiphase Hepatic CT

Objectives

Respiration-induced motion in the liver causes potential errors on the measurement of contrast medium in abdominal artery from multiphase hepatic CT scans. In this study, we investigated the use of hepatic CT images to quantitatively estimate the abdominal artery motion due to respiration by optical flow method.

Materials and Methods

A total of 132 consecutive patients were included in our patient cohort. We apply the optical flow method to compute the motion of the abdominal artery due to respiration.

Results

The minimum and maximum displacements of the abdominal artery motion were 0.02 and 30.87 mm by manual delineation, 0.03 and 40.75 mm calculated by optical flow method, respectively. Both high consistency and correlation between the present method and the physicians’ manual delineations were acquired with the regression equation of movement, y = 0.81x+0.25, r = 0.95, p<0.001.

Conclusion

We estimated the motion of abdominal artery due to respiration using the optical flow method in multiphase hepatic CT scans and the motion estimations were validated with the visualization of physicians. The quantitative analysis of respiration-related movement of abdominal artery could be used for motion correction in the measurement of contrast medium passing though abdominal artery in multiphase CT liver scans.     

Surgical Management for Thoracic Spinal Tuberculosis Posterior Only versus Anterior Video-Assisted Thoracoscopic Surgery

Study Design

A comparable retrospective study.

Object

To compare the clinical outcomes of surgical treatment by posterior only and anterior video-assisted thoracoscopic surgery for thoracic spinal tuberculosis (TSTB).

Method

145 patients with TSTB treated by two different surgical procedures in our institution from June 2001 to June 2014 were studied. All cases were retrospectively analyzed and divided into two groups according to the given treatments: 75 cases (32F/43M) in group A performed single-stage posterior debridement, transforaminal thoracic interbody fusion and instrumentation, and 70 cases (30F/40M) in group B underwent anterior video-assisted thoracoscopic surgery (VATS). Clinical and radiographic results in the two groups were analyzed and compared.

Results

Patients in group A and B were followed up for an average of 4.6±1.8, 4.4±1.2 years, respectively. There was no statistically significant difference between groups in terms of the operation time, blood loss, bony fusion, neurological recovery and the correction angle of kyphotic deformity (P>0.05). Fewer pulmonary complications were observed in group A. Good clinical outcomes were achieved in both groups.

Conclusions

Both the anterior VATS and posterior approaches can effectively treat thoracic tuberculosis. Nevertheless, the posterior approach procedure obtained less morbidity and complications than the other.     

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

Background and Purpose

The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms.

Materials and Methods

In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms.

Results

While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041).

Conclusions

Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms.     

Therapeutic Hypothermia Modifies Perinatal Asphyxia-Induced Changes of the Corpus Callosum and Outcome in Neonates

What Is Known about this Subject?

Diffusion-weighted MRI has demonstrated changes in the corpus callosum of term neonates with perinatal asphyxia. The severity of cerebral changes demonstrated using diffusion-weighted MRI is difficult to assess without measuring values of the Apparent Diffusion Coefficient (ADC).

What Is New?

ADC values of the anterior part of the corpus callosum are slightly higher than of the posterior part in full term infants with perinatal asphyxia. Low ADC values of the corpus callosum were associated with an adverse outcome in infants with perinatal asphyxia. In infants treated with hypothermia lower ADC values than with normothermia were associated with a poor outcome, supporting neuroprotective effects of hypothermia

Background

Using MRI, changes can be detected in the corpus callosum (CC) following perinatal asphyxia which are associated with later neurodevelopmental outcome.

Aim

To study the association between the apparent diffusion coefficient of water (ADC) in the CC on MRI in neonates with perinatal asphyxia and neurodevelopmental outcome at 18 months of age.

Subjects, Methods

Of 121 infants 32 (26%) died and 13 (11%) survived with an adverse neurological outcome. Sixty-five (54%) received therapeutic hypothermia. MRI was performed within 7 days after birth using a 1.5 T or 3.0 T system, and ADC values were measured in the anterior and posterior CC. The association between ADC and composite outcome (death or abnormal neurodevelopment) was analyzed for both normothermia and hypothermia cases using receiver operating characteristics.

Results

ADC values of the posterior CC were lower than of the anterior part (mean difference 0.050 x 10^-3 mm²/s, p<0.001). Field strength did not affect ADC values. ADC values of the posterior part of the CC were significantly lower in infants with basal ganglia/thalamus or near total brain injury (p<0.001). Lower ADC values were associated with an adverse outcome, but cut-off levels were lower after hypothermia (1.024 x 10^-3 mm²/s vs 0.969 x 10^-3 mm²/s)

Conclusion

Low ADC values of the posterior part of the corpus callosum are associated with an adverse outcome in term or near term neonates with perinatal asphyxia. Therapeutic hypothermia slightly modifies this association, showing that lower values were needed for an adverse outcome.     

Type 1 Retinopathy of Prematurity and Its Laser Treatment of Large Preterm Infants in East China

Purpose

To describe Type 1 retinopathy of prematurity (ROP) and its laser treatment outcomes in premature infants with birth weight > 1250 g in Eastern China.

Methods

A retrospective review of 3175 ROP records was conducted at Shanghai Eye & ENT Hospital of Fudan University. The records were collected at the ROP clinic from 2006 to 2014, including their demographic and medical information such as gestational age, birth weight, supplemental oxygen therapy, systemic complications, ROP stage, location, presence of plus disease. All infants were examined by RetCam fundus camera. Those with Type 1 ROP were also examined by indirect ophthalmoscope before undergoing transpupillary laser treatment.

Results

A total of 12 infants (24 eyes) with Type 1 ROP and birth weight > 1250 g were enrolled. All infants enrolled had plus disease and ROP in zone II retina. Specifically, 16 eyes (67%) had stage 2 ROP. 8 eyes (33%) had stage 3 ROP. ROP regressed in 23 eyes (96%) following laser treatment. Partial retinal detachment developed in one eye (4%). No severe involution sequelaes or laser-related complications were recorded. Mean follow-up was 30±6 weeks.

Conclusion

Type 1 ROP may occur in large premature infants who have undergone supplemental oxygen therapy. This Type 1 ROP is mainly located in zone II retina. Laser treatment is a safe and effective intervention for these infants.     

Relationship between Auditory and Cognitive Abilities in Older Adults

Objective

The objective was to evaluate the association of peripheral and central hearing abilities with cognitive function in older adults.

Methods

Recruited from epidemiological studies of aging and cognition at the Rush Alzheimer’s Disease Center, participants were a community-dwelling cohort of older adults (range 63–98 years) without diagnosis of dementia. The cohort contained roughly equal numbers of Black (n=61) and White (n=63) subjects with groups similar in terms of age, gender, and years of education. Auditory abilities were measured with pure-tone audiometry, speech-in-noise perception, and discrimination thresholds for both static and dynamic spectral patterns. Cognitive performance was evaluated with a 12-test battery assessing episodic, semantic, and working memory, perceptual speed, and visuospatial abilities.

Results

Among the auditory measures, only the static and dynamic spectral-pattern discrimination thresholds were associated with cognitive performance in a regression model that included the demographic covariates race, age, gender, and years of education. Subsequent analysis indicated substantial shared variance among the covariates race and both measures of spectral-pattern discrimination in accounting for cognitive performance. Among cognitive measures, working memory and visuospatial abilities showed the strongest interrelationship to spectral-pattern discrimination performance.

Conclusions

For a cohort of older adults without diagnosis of dementia, neither hearing thresholds nor speech-in-noise ability showed significant association with a summary measure of global cognition. In contrast, the two auditory metrics of spectral-pattern discrimination ability significantly contributed to a regression model prediction of cognitive performance, demonstrating association of central auditory ability to cognitive status using auditory metrics that avoided the confounding effect of speech materials.     

Comparison of Cervical Spine Anatomy in Calves,Pigs and Humans

Background Context

Animals are commonly used to model the human spine for in vitro and in vivo experiments. Many studies have investigated similarities and differences between animals and humans in the lumbar and thoracic vertebrae. However, a quantitative anatomic comparison of calf, pig, and human cervical spines has not been reported.

Purpose

To compare fundamental structural similarities and differences in vertebral bodies from the cervical spines of commonly used experimental animal models and humans.

Study Design

Anatomical morphometric analysis was performed on cervical vertebra specimens harvested from humans and two common large animals (i.e., calves and pigs).

Methods

Multiple morphometric parameters were directly measured from cervical spine specimens of twelve pigs, twelve calves and twelve human adult cadavers. The following anatomical parameters were measured: vertebral body width (VBW), vertebral body depth (VBD), vertebral body height (VBH), spinal canal width (SCW), spinal canal depth (SCD), pedicle width (PW), pedicle depth (PD), pedicle inclination (PI), dens width (DW), dens depth (DD), total vertebral width (TVW), and total vertebral depth (TVD).

Results

The atlantoaxial (C1–2) joint in pigs is similar to that in humans and could serve as a human substitute. The pig cervical spine is highly similar to the human cervical spine, except for two large transverse processes in the anterior regions ofC4–C6. The width and depth of the calf odontoid process were larger than those in humans. VBW and VBD of calf cervical vertebrae were larger than those in humans, but the spinal canal was smaller. Calf C7 was relatively similar to human C7, thus, it may be a good substitute.

Conclusion

Pig cervical vertebrae were more suitable human substitutions than calf cervical vertebrae, especially with respect to C1, C2, and C7. The biomechanical properties of nerve vascular anatomy and various segment functions in pig and calf cervical vertebrae must be considered when selecting an animal model for research on the spine.     

The Silk Road Health Project: How Mobility and Migration Status Influence HIV Risks among Male Migrant Workers in Central Asia

Objectives

We examined whether mobility, migrant status, and risk environments are associated with sexually transmitted infections (STIs) and HIV risk behaviors (e.g. sex trading, multiple partners, and unprotected sex).

Methods

We used Respondent Driven Sampling (RDS) to recruit external male migrant market vendors from Kyrgyzstan, Uzbekistan, and Tajikistan as well internal migrant and non-migrant market vendors from Kazakhstan. We conducted multivariate logistic regressions to examine the effects of mobility combined with the interaction between mobility and migration status on STIs and sexual risk behaviors, when controlling for risk environment characteristics.

Results

Mobility was associated with increased risk for biologically-confirmed STIs, sex trading, and unprotected sex among non-migrants, but not among internal or external migrants. Condom use rates were low among all three groups, particularly external migrants. Risk environment factors of low-income status, debt, homelessness, and limited access to medical care were associated with unprotected sex among external migrants.

Conclusion

Study findings underscore the role mobility and risk environments play in shaping HIV/STI risks. They highlight the need to consider mobility in the context of migration status and other risk environment factors in developing effective prevention strategies for this population.     

High-Resolution Postcontrast Time-of-Flight MR Angiography of Intracranial Perforators at 7.0 Tesla

Background and Purpose

Different studies already demonstrated the benefits of 7T for precontrast TOF-MRA in the visualization of intracranial small vessels. The aim of this study was to assess the performance of high-resolution 7T TOF-MRA after the administration of a gadolinium-based contrast agent in visualizing intracranial perforating arteries.

Materials and Methods

Ten consecutive patients (7 male; mean age, 50.4 ± 9.9 years) who received TOF-MRA at 7T after contrast administration were retrospectively included in this study. Intracranial perforating arteries, branching from the parent arteries of the circle of Willis, were identified on all TOF-MRA images. Provided a TOF-MRA before contrast administration was present, a direct comparison between pre- and postcontrast TOF-MRA was made.

Results

It was possible to visualize intracranial perforating arteries branching off from the entire circle of Willis, and their proximal branches. The posterior cerebral artery (P1 and proximal segment of P2) appeared to have the largest number of visible perforating branches (mean of 5.1 in each patient, with a range of 2–7). The basilar artery and middle cerebral artery (M1 and proximal segment M2) followed with a mean number of 5.0 and 3.5 visible perforating branches (range of 1–9 and 1–8, respectively). Venous contamination in the postcontrast scans sometimes made it difficult to discern the arterial or venous nature of a vessel.

Conclusion

High-resolution postcontrast TOF-MRA at 7T was able to visualize multiple intracranial perforators branching off from various parts of the circle of Willis and proximal intracranial arteries. Although confirmation in a larger study is needed, the administration of a contrast agent for high-resolution TOF-MRA at 7T seems to enable a better visualization of the distal segment of certain intracranial perforators.     

Vascular Complications of Intercavernous Sinuses during Transsphenoidal Surgery: An Anatomical Analysis Based on Autopsy and Magnetic Resonance Venography

Purpose

Vascular complications induced by intercavernous sinus injury during dural opening in the transsphenoidal surgery may contribute to incomplete tumour resections. Preoperative neuro-imaging is of crucial importance in planning surgical approach. The aim of this study is to correlate the microanatomy of intercavernous sinuses with its contrast-enhanced magnetic resonance venography (CE-MRV).

Methods

Eighteen human adult cadavers and 24 patients were examined based on autopsy and CE-MRV. Through dissection of the cadavers and CE-MRV, the location, shape, number, diameter and type of intercavernous sinuses were measured and compared.

Results

Different intercavernous sinuses were identified by their location and shape in all the cadavers and CE-MRV. Compared to the cadavers, CE-MRV revealed 37% of the anterior intercavernous sinus, 48% of the inferior intercavernous sinus, 30% of the posterior intercavernous sinus, 30% of the dorsum sellae sinus and 100% of the basilar sinus. The smaller intercavernous sinuses were not seen in the neuro-images. According to the presence of the anterior and inferior intercavernous sinus, four types of the intercavernous sinuses were identified in cadavers and CE-MRV, and the corresponding operative space in the transsphenoidal surgical approach was implemented.

Conclusion

The morphology and classification of the cavernous sinus can be identified by CE-MRV, especially for the larger vessels, which cause bleeding more easily. Therefore, CE-MRV provides a reliable measure for individualized preoperative planning during transsphenoidal surgery.     

Use of a Green Familiar Faces Paradigm Improves P300-Speller Brain-Computer Interface Performance

Background

A recent study showed improved performance of the P300-speller when the flashing row or column was overlaid with translucent pictures of familiar faces (FF spelling paradigm). However, the performance of the P300-speller is not yet satisfactory due to its low classification accuracy and information transfer rate.

Objective

To investigate whether P300-speller performance is further improved when the chromatic property and the FF spelling paradigm are combined.

Methods

We proposed a new spelling paradigm in which the flashing row or column is overlaid with translucent green pictures of familiar faces (GFF spelling paradigm). We analyzed the ERP waveforms elicited by the FF and proposed GFF spelling paradigms and compared P300-speller performance between the two paradigms.

Results

Significant differences in the amplitudes of four ERP components (N170, VPP, P300, and P600f) were observed between both spelling paradigms. Compared to the FF spelling paradigm, the GFF spelling paradigm elicited ERP waveforms of higher amplitudes and resulted in improved P300-speller performance.

Conclusions

Combining the chromatic property (green color) and the FF spelling paradigm led to better classification accuracy and an increased information transfer rate. These findings demonstrate a promising new approach for improving the performance of the P300-speller.