Molecular characterization of 13 patients with PIK3CA-related overgrowth spectrum using a targeted deep sequencing approach

Activating variants in the PIK3CA gene cause a heterogeneous spectrum of disorders that involve congenital or early-onset segmental/focal overgrowth, now referred to as PIK3CA-related overgrowth spectrum (PROS). Historically, the clinical diagnoses of patients with PROS included a range of distinct syndromes, including CLOVES syndrome, dysplastic megalencephaly, hemimegalencephaly, focal cortical dysplasia, Klippel-Trenaunay syndrome, CLAPO syndrome, fibroadipose hyperplasia or overgrowth, hemihyperplasia multiple lipomatosis, and megalencephaly capillary malformation-polymicrogyria (MCAP) syndrome. MCAP is a sporadic overgrowth disorder that exhibits core features of progressive megalencephaly, vascular malformations, distal limb malformations, cortical brain malformations, and connective tissue dysplasia. In 2012, our research group contributed to the identification of predominantly mosaic, gain-of-function variants in PIK3CA as an underlying genetic cause of the syndrome. Mosaic variants are technically more difficult to detect and require implementation of more sensitive sequencing technologies and less stringent variant calling algorithms. In this study, we demonstrated the utility of deep sequencing using the Illumina TruSight Oncology 500 (TSO500) sequencing panel in identifying variants with low allele fractions in a series of patients with PROS and suspected mosaicism: pathogenic, mosaic PIK3CA variants were identified in all 13 individuals, including 6 positive controls. This study highlights the importance of screening for low-level mosaic variants in PROS patients. The use of targeted panels with deep sequencing in clinical genetic testing laboratories would improve diagnostic yield and accuracy within this patient population.

Comparing Three Methods of Therapeutic Hypothermia Among Transported Neonates with Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) and associated multiorgan injury are significant causes of morbidity and mortality in term and near-term neonates. Therapeutic hypothermia (TH) is the current standard of care for neuroprotection in neonates with HIE. In our experience, the majority of babies born with HIE were found in nontertiary care facilities in our region, where effective methods of cooling during transport to tertiary care centers are desirable. Most centers initiate passive TH at referral hospitals, while active cooling is typically initiated during transport. The objective of this study was to evaluate the effectiveness of three methods of cooling during transport of neonates with HIE in southern Alberta. In this prospective cohort study, 186 neonates with HIE were transported between January 2013 and December 2021. Among the 186 neonates, 47 were passively cooled, 36 actively cooled with gel packs, and 103 cooled with a servo-controlled cooling device. The clinical characteristics were comparable for the three groups, with no difference in adverse events. Fifteen neonates (8%) died and 54 neonates (29%) suffered radiologically determined brain injury. Servo-controlled cooling was found to be superior to other methods in maintaining a target temperature without significant fluctuation during transport and with temperature in the target range on arrival at tertiary care facilities. The rate of overcooling was also lower in the servo-controlled group compared with other groups. There were no statistically significant differences between the groups in relation to mortality and brain MRI changes associated with HIE. Adjusting for GA, 10-minute Apgar score, base excess, HIE stage, and need for intubation during transport, passive cooling increased the odds of temperature fluctuation outside the range by 12-fold and gel pack cooling by 13-fold compared with servo-controlled cooling. The use of servo-controlled TH devices should be the preferred practice wherever feasible. (REB17-1334_REN3).

Neuroprotection care bundle implementation is associated with improved long-term neurodevelopmental outcomes in extremely premature infants

OBJECTIVE

To study the impact of an evidence-based neuroprotection care (NPC) bundle on long-term neurodevelopmental impairment (NDI) in infants born extremely premature.

STUDY DESIGN

An NPC bundle targeting predefined risk factors for acute brain injury in extremely preterm infants was implemented. We compared the incidence of composite outcome of death or severe neurodevelopmental impairment (sNDI) at 21 months adjusted age pre and post bundle implementation.

RESULTS

Adjusting for confounding factors, NPC bundle implementation associated with a significant reduction in death or sNDI (aOR, 0.34; 95% CI 0.17-0.68; P = 0.002), mortality (aOR, 0.31; 95% CI (0.12-0.79); P = 0.015), sNDI (aOR, 0.37; 95% CI: 0.12-0.94; P = 0.039), any motor, language, or cognitive composite score <70 (aOR, 0.48; 95% CI: 0.26-0.90; P = 0.021).

CONCLUSION

Implementation of NPC bundle targeting predefined risk factors is associated with a reduction in mortality or sNDI in extremely preterm infants.

Post-hemorrhagic ventricular dilatation: inter-observer reliability of ventricular size measurements in extremely preterm infants

BACKGROUND

Post-hemorrhagic ventricular dilatation (PHVD) in preterm infants can be assessed with ventricular size indices from cranial ultrasound. We explored inter-observer reliability of these indices for prediction of severe PHVD.

METHODS

For all 139 infants with IVH, serial neonatal ultrasound at 3 time points (days 4-7, day 14, 36 weeks PMA) were assessed independently by 3 observers with differing levels of training/experience. Ventricular index (VI), anterior horn width (AHW), and fronto-temporal horn ratio (FTHR) were measured and used to diagnose PHVD. For all, inter-observer reliability and predictive values for receipt of surgical intervention were calculated.

RESULTS

Inter-observer reliability for all observers varied from poor to excellent, with higher reliability for VI/AHW (ICC 0.49-0.84/0.51-0.81) than FTHR (0.41-0.82), particularly from the second week. Good-excellent inter-expertise reliability was found between observers with ample experience/training (0.65-0.99), particularly for VI and AHW, while poor-moderate when comparing with an inexperienced observer (0.28-0.88). Slightly higher predictive value for PHVD intervention (n = 12) was found for AHW (AUC 0.86-0.96) than for VI and FTHR (0.80-0.96/0.80-0.95).

CONCLUSIONS

AHW and VI are highly reproducible in experienced hands compared to FTHR, with AHW from the second week onwards being the strongest predictor for receiving surgical intervention for severe PHVD. AHW may aid in early PHVD diagnosis and decision-making on intervention.

IMPACT

While ventricular size indices from serial cUS are superior to clinical signs of increased intracranial pressure to assess PHVD, questions remained on their inter-observer reproducibility and reliability to predict severity of PHVD. AHW and VI are highly reproducible when performed by experienced clinicians. AHW from the second week of birth is the strongest predictor of PHVD onset and severity. AHW, combined with VI, may aid in early PHVD diagnosis and decision-making on need for surgical intervention. Consistent use of these indices has the potential to improve PHVD management and therewith the long-term outcomes in preterm infants.

Consensus Approach for Standardizing the Screening and Classification of Preterm Brain Injury Diagnosed With Cranial Ultrasound: A Canadian Perspective

Acquired brain injury remains common in very preterm infants and is associated with significant risks for short- and long-term morbidities. Cranial ultrasound has been widely adopted as the first-line neuroimaging modality to study the neonatal brain. It can reliably detect clinically significant abnormalities that include germinal matrix and intraventricular hemorrhage, periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, cerebellar hemorrhage, and white matter injury. The purpose of this article is to provide a consensus approach for detecting and classifying preterm brain injury to reduce variability in diagnosis and classification between neonatologists and radiologists. Our overarching goal with this work was to achieve homogeneity between different neonatal intensive care units across a large country (Canada) with regards to classification, timing of brain injury screening and frequency of follow up imaging. We propose an algorithmic approach that can help stratify different grades of germinal matrix-intraventricular hemorrhage, white matter injury, and ventricular dilatation in very preterm infants.

Neuroprotection Care Bundle Implementation to Decrease Acute Brain Injury in Preterm Infants

BACKGROUND

We assessed the impact of an evidence-based neuroprotection care bundle on the risk of brain injury in extremely preterm infants.

METHODS

We implemented a neuroprotection care bundle consisting of a combination of neuroprotection interventions such as minimal handling, midline head position, deferred cord clamping, and protocolization of hemodynamic and respiratory managements. These interventions targeted risk factors for acute brain injury in extremely preterm infants (born at gestational age less than 29 weeks) during the first three days of birth. Implementation occurred in a stepwise manner, including care bundle development by a multidisciplinary care team based on previous evidence and experience, standardization of outcome assessment tools, and education. We compared the incidence of the composite outcome of acute preterm brain injury or death preimplementation and postimplementation.

RESULTS

Neuroprotection care bundle implementation associated with a significant reduction in acute brain injury risk factors such as the use of inotropes (24% before, 7% after, P value < 0.001) and fluid boluses (37% before, 19% after, P value < 0.001), pneumothorax (5% before, 2% after, P value = 0.002), and opioid use (19% before, 7% after, P value < 0.001). Adjusting for confounding factors, the neuroprotection care bundle significantly reduced death or severe brain injury (adjusted odds ratio, 0.34; 95% confidence interval, 0.20 to 0.59; P value < 0.001) and severe brain injury (adjusted odds ratio, 0.31; 95% confidence interval, 0.17 to 0.58; P < 0.001).

CONCLUSIONS

Implementation of neuroprotection care bundle targeting predefined risk factors is feasible and effective in reducing acute brain injury in extremely preterm infants.

Impact of outreach education program on outcomes of neonates with hypoxic ischemic encephalopathy

Aim

To evaluate the impact of outreach education targeting neuroprotection on outcomes of outborn infants with moderate-to-severe hypoxic ischemic encephalopathy (HIE).

Methods

A retrospective cohort study of infants admitted with moderate-to-severe HIE was conducted following the implementation of outreach education in January 2016. Key interventions were early identification and referral of infants with encephalopathy utilizing telemedicine and a centralized communication system, hands-on simulation, and interactive case discussion and dissemination of clinical management guidelines and educational resources. The association between the intervention and a composite outcome of death and/or severe brain injury on brain magnetic resonance imaging (MRI) was tested controlling for the confounding factors.

Results

Of 165 neonates, 37 (22.4%) died and/or had a severe brain injury. This outcome decreased from 35% (27/77) to 11% (10/88) following the implementation of outreach education (P<0.001). Eligible infants not undergoing therapeutic hypothermia within 6 hours from birth decreased from 19.5% (15/77) to 4.5% (4/88). The use of inotropes decreased from 49.3% (38/77) to 19.6% (13/88). Any core temperature below 33°C was recorded for 20/53 (38%) before and 16/78 (21%) after, while those within the target range of 33°C to 34°C at admission to a tertiary care facility increased from (15/53) 28% to (51/88) 58%. Outreach education was independently associated with decreased composite outcome of death and/or severe brain injury on MRI (adjusted odds ratio 0.2; 95% confidence interval 0.07 to 0.52).

Conclusion

Outreach education targeting neuroprotection for infants with moderate-to-severe HIE was associated with a reduction in death and/or severe brain injury.

Simulation-Based Structured Education Supports Focused Neonatal Cranial Ultrasound Training

OBJECTIVES

Brain injury in preterm neonates may cause clinical deterioration and requires timeous bedside diagnosis. Teaching cranial ultrasound (US) skills using fragile preterm neonates is challenging. The purpose of this study was to test the effectiveness and feasibility of using task-trainer computer-based simulators and US-suitable cranial phantoms in combination with teaching sessions in teaching novices to perform focused cranial US evaluations for identifying substantial intraventricular hemorrhage.

METHODS

This was a prospective interventional educational study targeting participants with no prior skills in neonatal cranial US. Participants attended a 2-day training workshop, with didactic and hands-on interactive sessions using computer-based and 3-dimensional printed phantom simulators. Participants then performed a cranial US scan on a healthy neonate to assess the diagnostic quality of the images acquired. Individual precourse and postcourse knowledge tests were compared. To test recall, participants also submitted US images acquired on neonates within 3 and 6 months of attending the course.

RESULTS

Forty-five participants completed the training modules. Mean knowledge scores increased significantly (in brain anatomy, brain physiology, intracranial disorders, and US physics domains). Thirty-eight cranial US scans were acquired during the course, 22 within 3 months after completion, and 34 within 6 months after completion. Thirty-two (84%) of the initial 38 case images, 17 (77%) of 22 images submitted within 3 months, and 32 (94%) of 34 images submitted within 6 months after course completion were of diagnostic quality.

CONCLUSIONS

A structured training module with didactic and hand-on training sessions using simulators and phantoms is feasible and supports training of clinicians to perform focused cranial US examinations.

Implementation of Neonatal Neurocritical Care Program Improved Short-Term Outcomes in Neonates With Moderate-to-Severe Hypoxic Ischemic Encephalopathy

BACKGROUND

Despite the introduction of therapeutic hypothermia, infants with moderate-to-severe hypoxic-ischemic encephalopathy remain at risk of mortality and morbidity. A dedicated service with standardized management protocols and improved communication may help improve care. We aimed to evaluate the impact of a dedicated neonatal neurocritical care service on short-term outcomes in infants with hypoxic-ischemic encephalopathy.

METHODS

We performed a retrospective cohort study (July 2008 to December 2017) on term and near-term infants admitted to two tertiary neonatal intensive care units with moderate-to-severe hypoxic-ischemic encephalopathy, before and after neonatal neurocritical care service implementation. The primary outcome was brain magnetic resonance imaging findings consistent with those of hypoxic-ischemic encephalopathy. Secondary outcomes included the cooling initiation rate, hospital stay duration, antiseizure medication use, and inotrope use. Regression analysis and interrupted time series analysis were performed after adjusting for confounding factors.

RESULTS

In total, 216 infants with moderate-to-severe hypoxic-ischemic encephalopathy were analyzed-109 before and 107 after neonatal neurocritical care implementation. After adjusting for confounding factors, there was a significant reduction in primary outcomes (adjusted odds ratio: 0.3, confidence interval: 0.15 to 0.57, P < 0.001) after neonatal neurocritical care implementation. Average hospital stay duration reduced by 5.2 days per infant (P = 0.03), identification of eligible infants for cooling improved (P < 0.001), antiseizure medication use reduced (P = 0.001), and early inotropes use reduced (P = 0.04).

CONCLUSION

Implementation of a neonatal neurocritical care service associated with decreased brain injury shortened the hospital stay duration and improved the care of infants with moderate-to-severe hypoxic-ischemic encephalopathy.

Imaging in Neuro-ophthalmology

PURPOSE OF REVIEW

This article discusses an approach to imaging in patients with neuro-ophthalmologic disorders, with emphasis on the clinical-anatomic localization of lesions affecting afferent and efferent visual function.

RECENT FINDINGS

Advances in MRI, CT, ultrasound, and optical coherence tomography have changed how neuro-ophthalmic disorders are diagnosed and followed in the modern clinical era.

SUMMARY

The advantages, disadvantages, and indications for various imaging techniques for neuro-ophthalmologic disorders are discussed, with a view to optimizing how these tools can be used to enhance patient care.

Intraventricular Hemorrhage: Risk Factors and Association With Patent Ductus Arteriosus Treatment in Extremely Preterm Neonates

Objectives: To assess maternal and neonatal risk factors for intraventricular hemorrhage (IVH). To examine the association of patent ductus arteriosus (PDA) and its treatment, with IVH and its severity. Study design: In this retrospective cohort study, we included preterm neonates born at <29 weeks, admitted to a tertiary level III Neonatal Intensive Care Unit in Calgary, Canada, between 2013 and 2016, who had a head ultrasound in the first 7 days of life. A subset analysis included neonates who also had cardiac ultrasound in the first 3 days of life. Results: Of the 495 neonates, 121 (24.4%) had IVH of any grade and 48 (9.7%) had severe IVH. Identified risk factors were small birth gestation and weight, lack of antenatal corticosteroids, maternal chorioamnionitis, Apgar score <5 at 5 min, umbilical cord pH < 7, respiratory distress syndrome, early onset sepsis, hypercapnia, pCO₂ fluctuations, prolonged intubation, inhaled nitric oxide, inotropes or normal saline boluses, metabolic derangements, opioids infusions, and bicarbonate/THAM therapy. In a primary analysis of the total cohort, when the decision to treat a PDA was used as a surrogate marker of its clinical significance, a PDA requiring treatment was associated with a higher risk of IVH. There was no significant difference in the incidence of IVH between neonates with early treatment of a clinically significant PDA compared to late, however early indomethacin treatment was associated with reduced severity of IVH. In the subset analysis, the presence of a hemodynamically significant PDA (hs-PDA) was not associated with a higher probability of IVH. Of those with severe IVH, 18 (55%) had a hs-PDA; this is clinically but not statistically significant. Conclusions: Identified risk factors should be the target of IVH reduction bundles. Early indomethacin treatment for a clinically significant PDA may reduce IVH severity.

Serum calcium derangements in neonates with moderate to severe hypoxic ischemic encephalopathy and the impact of therapeutic hypothermia: a cohort study

Background: Perinatal hypoxia is a recognized cause of hypocalcemia in neonates in the first 3 days of life. Therapeutic hypothermia (TH) promotes neuroprotection by decreasing calcium influx into the cells during the reperfusion phase thereby increase serum calcium levels. This study examines the trends of serum calcium levels in neonates with hypoxic ischemic encephalopathy (HIE) and the effect of TH.Material and methods: A retrospective cohort study of neonates with moderate to severe HIE admitted to level III neonatal intensive care units (NICU's) in Calgary between September 2011 and October 2015. HIE was staged using modified Sarnat scoring system. Ionized calcium levels were followed in the first 3 days of age.Results: One hundred thirteen neonates admitted with the diagnosis of moderate to severe HIE were included; 89 (79%) underwent TH. Hypercalcemia was significantly higher with TH 57 (64%) compared to 8 (33%) in noncooled group (p = .007). Hypocalcemia was less in TH group; 11 (12%) compared to 5 (21%) in non TH group. Hypo/hypercarbia did not alter the serum calcium levels. Furthermore; there was no increase in the incidence of intracranial hemorrhage, clinical or electrographic seizures, antiepileptic drug use, or hypoxic/ischemic MRI changes with calcium derangements.Conclusion: The incidence of hypocalcemia was reduced by almost half and hypercalcemia was significantly increased with TH in the first 3 days of life. The reduction in hypocalcemia and the increase in hypercalcemia may be attributed to the neuroprotective effect of TH.

Abstract P6-11-08: Safety and efficacy results from phase I study of BYL 719 plus nab-paclitaxel in HER 2 negative metastatic breast cancer

Introduction

Mutations/deregulations in the phosphatidylinositol-3-kinase (PI3K) pathway are common in breast cancer, Inhibition of the PI3K pathway is recognized as a promising target for the treatment of breast cancer. Although taxanes are effective early on in advanced stage breast cancer, resistance often develops. It has been demonstrated that activation of the PI3K/AKT pathway confers resistance to paclitaxel, and in preclinical models, concomitant inhibition of the PI3K pathway enhances the efficacy of taxanes. BYL719 is a potent oral, class I PI3K inhibitor which strongly inhibits the PI3K alpha isoforms and is significantly less active against the other class I isoforms. Targeting the alpha isoform of PI3K is expected to improve the therapeutic window over inhibitors with less isoform specificity. Nab-Paclitaxel is a solvent-free, nanoparticle, albumin-based paclitaxel which takes advantage of the antitumor activity of paclitaxel while decreasing the toxicities typically associated with the solvent (Cremophor) used to administer the most common formulation of paclitaxel.

Methods

A 3+3 dose-escalation design evaluated three dose levels of BYL719 (250mg, 300mg, and 350mg) administered PO once daily (D1-28) with nab-Paclitaxel (100 mg/m2 intravenously D 1, 8, 15) every 28 days in patients with metastatic HER 2 negative breast cancer. The aims of the study were to 1) determine the recommended phase II dose (RPTD) of BYL719 + nab-Paclitaxel, 2) assess pharmacokinetics of BYL and nab-paclitaxel, and 3) assess preliminary efficacy.

Results

10 patients were enrolled at 3 dose levels of BYL719 and 3 patients were enrolled in expansion cohort at the RPTD of BYL719 of 350 mg PO daily plus nab-paclitaxel 100mg/m2 (D 1, 8, 15). Median age was 61years; 54% (7/13) of patients were hormone receptor positive and 46% (6/13) triple negative. 85% (11/13) had visceral disease, 69% (9/13) had received prior chemotherapy for metastatic disease and 85% (11/13) had received prior taxane in adjuvant/metastatic setting. There were no DLTs in the three cohorts and the MTD of BYL was not reached. Hyperglycemia (G3:31%, G4:0%) and neutropenia (G3:15%, G4:8%), were the most common grade 3/4 adverse events. There were no Grade 3/4 diarrhea or rash. Best overall response for 12 patients was 58% (7/12) (complete response=1, partial response=6), and an additional 33% (4/12) demonstrated stable disease. Objective responses were noted in both hormone positive and triple negative disease. Median duration of response is 6.5 months (range 2-14 months). No pharmacokinetic interactions were detected when BYL and nab-paclitaxel were co-administered.

Discussion:

This phase I study demonstrates that combination of BYL719 and nab-paclitaxel was well tolerated and shows encouraging efficacy in metastatic HER2 negative breast cancer. Enrollment in the phase II portion of the trial at the RPTD (BYL719 350mg PO daily plus nab-paclitaxel 100mg/m2 D1,8,15 every 28 days) continues. Ongoing analysis of PI3K pathway alterations in tumor and cfDNA will be correlated with clinical response.

Citation Format: Sharma P, Abramson VG, O'Dea A, Lewis S, Scott JN, Ward J, De Jong JA, Lehn C, Brown AR, Williamson SK, Perez RP, Komiya T, Godwin AK, Reed GA, Khan QJ. Safety and efficacy results from phase I study of BYL 719 plus nab-paclitaxel in HER 2 negative metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-11-08.

A New IVH Scoring System Based on Laterality Enhances Prediction of Neurodevelopmental Outcomes at 3 Years Age in Premature Infants

Objective To compare the new intraventricular hemorrhage (IVH) Abdi score to the Papile grading system of IVH for prediction of composite outcome of death or neurodevelopmental impairment (NDI). Methods In a cohort study, all preterm infants with IVH who were born ≤1,250 g and/or ≤ 28 weeks of gestation at birth were prospectively followed up in our neonatal follow-up clinic. All cranial ultrasounds of the included infants were reviewed by neuroradiologists who were blinded to the clinical data and neurodevelopmental outcomes. Cranial ultrasounds were graded according to the Papile scoring system and by calculation of the Abdi score. Results A total of 183 preterm infants met inclusion and exclusion criteria. Of these, 80 (44%) had the composite primary outcome of death or NDI (51 died, 29 survived with NDI). The area under receiver operating characteristic curve for predicting death or NDI was 0.87 (95% confidence interval [CI]: 0.81-0.93) for Abdi score and 0.85 (95% CI: 0.79-0.91) for Papile grading (p = 0.04). Abdi scores had higher specificity than Papile grade II at Abdi score 5 (63.9 vs. 39.2%; p < 0.001) and Abdi score 6 (73.2 vs. 39.2%; p < 0.001). Conclusion Abdi scores seem to be more specific than Papile grading system in predicting death or NDI by 3 years' corrected age.

Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8

Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development.

Validity of the diagnostic criteria for chronic cerebrospinal venous insufficiency and association with multiple sclerosis

BACKGROUND

The chronic cerebrospinal venous insufficiency theory proposes that altered cerebral venous hemodynamics play a role in the pathophysiology of multiple sclerosis. We aimed to explore the validity of this hypothesis by assessing the diagnostic criteria for chronic cerebrospinal venous insufficiency in persons with and without multiple sclerosis.

METHODS

We compared the proportion of venous outflow abnormalities between patients with multiple sclerosis and healthy controls using extracranial Doppler ultrasonography and gadolinium-enhanced magnetic resonance venography. Interpreting radiologists were blinded to the clinical status of participants.

RESULTS

We enrolled 120 patients with multiple sclerosis and 60 healthy controls. High proportions of both patients (67/115 [58%]) and controls (38/60 [63%]) met 1 or more of the proposed ultrasound criteria for diagnosis of chronic cerebrospinal venous insufficiency (p = 0.6). A minority of patients (23/115 [20%]) and controls (6/60 [10%]) fulfilled 2 or more of the proposed criteria (p = 0.1). There were no differences between patients and controls in the prevalence of each individual ultrasound criterion. Similarly, there were no differences in intracranial or extracranial venous patency between groups, as measured by magnetic resonance venography.

INTERPRETATION

We detected no differences in the proportion of venous outflow abnormalities between patients with multiple sclerosis and healthy controls. Moreover, our study revealed significant methodologic concerns regarding the proposed diagnostic criteria for chronic cerebrospinal venous insufficiency that challenge their validity.

MRI texture heterogeneity in the optic nerve predicts visual recovery after acute optic neuritis

PURPOSE

To test the feasibility of using multi-scale MRI texture analysis to assess optic nerve pathology and to investigate how visual recovery relates to the severity of acute tissue damage in the optic nerve in patients after optic neuritis (ON).

MATERIALS AND METHODS

We recruited 25 patients with acute ON. Retinal nerve fiber layer (RNFL) thickness; MRI lesion length and enhancement; optic nerve area ratio; and multi-scale MRI texture analysis, a measure of structural integrity, were used to assess tissue damage at baseline, and at 6 and 12 months. The recovery in vision was defined as the functional outcome. Eight healthy subjects were imaged for control.

RESULTS

We identified 25 lesions in the affected eyes (9 enhanced) and 5 in the clinically non-affected eyes (none enhanced). At baseline, we found that RNFL values were 20% thicker and lesion texture 14% more heterogeneous in the affected eyes than in the non-affected eyes, and lesion texture ratio of affected to non-affected eyes was greater in patients than in controls. In the affected eyes, visual acuity recovered significantly over 6 (18/23 patients) and 12 months (18/21 patients) when RNFL thickness and optic nerve area ratio decreased over time. Texture heterogeneity in the standard MRI of acute optic nerve lesions was the only measure that predicted functional recovery after ON.

CONCLUSIONS

Tissue heterogeneity may be a potential measure of functional outcome in ON patients and advanced analysis of the texture in standard MRI could provide insights into mechanisms of injury and recovery in patients with similar disorders.

Neurological outcome scale for traumatic brain injury: III. Criterion-related validity and sensitivity to change in the NABIS hypothermia-II clinical trial

The neurological outcome scale for traumatic brain injury (NOS-TBI) is a measure assessing neurological functioning in patients with TBI. We hypothesized that the NOS-TBI would exhibit adequate concurrent and predictive validity and demonstrate more sensitivity to change, compared with other well-established outcome measures. We analyzed data from the National Acute Brain Injury Study: Hypothermia-II clinical trial. Participants were 16-45 years of age with severe TBI assessed at 1, 3, 6, and 12 months postinjury. For analysis of criterion-related validity (concurrent and predictive), Spearman's rank-order correlations were calculated between the NOS-TBI and the glasgow outcome scale (GOS), GOS-extended (GOS-E), disability rating scale (DRS), and neurobehavioral rating scale-revised (NRS-R). Concurrent validity was demonstrated through significant correlations between the NOS-TBI and GOS, GOS-E, DRS, and NRS-R measured contemporaneously at 3, 6, and 12 months postinjury (all p<0.0013). For prediction analyses, the multiplicity-adjusted p value using the false discovery rate was <0.015. The 1-month NOS-TBI score was a significant predictor of outcome in the GOS, GOS-E, and DRS at 3 and 6 months postinjury (all p<0.015). The 3-month NOS-TBI significantly predicted GOS, GOS-E, DRS, and NRS-R outcomes at 6 and 12 months postinjury (all p<0.0015). Sensitivity to change was analyzed using Wilcoxon's signed rank-sum test of subsamples demonstrating no change in the GOS or GOS-E between 3 and 6 months. The NOS-TBI demonstrated higher sensitivity to change, compared with the GOS (p<0.038) and GOS-E (p<0.016). In summary, the NOS-TBI demonstrated adequate concurrent and predictive validity as well as sensitivity to change, compared with gold-standard outcome measures. The NOS-TBI may enhance prediction of outcome in clinical practice and measurement of outcome in TBI research.

A randomized phase II study comparing capecitabine alone with capecitabine and oral cyclophosphamide in patients with advanced breast cancer-cyclox II

BACKGROUND

Capecitabine and cyclophosphamide are active in patients with advanced breast cancer, have non-overlapping toxic effects and synergy pre-clinically. We explored the efficacy and toxic effect of an all-oral combination of capecitabine with cyclophosphamide versus capecitabine alone in a multicentre, randomized, phase II study.

PATIENTS AND METHODS

Patients with locally advanced or metastatic breast cancer were randomized to treatment with capecitabine given continuously (666 mg/m(2) b.i.d. days 1-28) alone (C) or with oral cyclophosphamide (100 mg/m(2) days 1-14 of a 28-day cycle) (CCy) for up to six cycles.

RESULTS

Eighty-two patients were randomized. There was no complete response. The proportions with partial response were 36% on C and 44% on CCy, a difference of 7.9% [95% confidence interval (CI) -13.4 to 29.1]. Significant toxic effect was uncommon: grade ≥3 diarrhoea in 4 (10%) versus 1 (3%) patients; grade ≥3 fatigue in 2 (5%) versus 5 patients (13%) and grade ≥2 hand-foot syndrome in 7 (17%) versus 11 (28%) patients receiving C versus CCy, respectively. Median progression-free survival was 3.1 months on C and 6.9 months on CCy, not significantly different statistically. There was no difference in overall survival.

CONCLUSION

The difference in tumour response suggests a reasonable chance that CCy is superior to C alone.

All-Optical Sensing of the Components of the Internal Local Electric Field in Proteins

Here, we present a new all-optical method of interrogation of the internal electric field vector inside proteins. The method is based on experimental evaluation of the permanent dipole moment change upon excitation and the pure electronic transition frequency of a fluorophore embedded in a protein matrix. The permanent dipole moment change can be obtained from two-photon absorption measurements. In addition, permanent dipole moment change, tensor of polarizability change, and transition frequency for the free chromophore should be calculated quantum-mechanically. This allows obtaining the components of the electric field by considering the second-order Stark shift. We use the fluorescent protein mCherry as an example to demonstrate the applicability of the method.

Magnetic resonance imaging of crossed cerebellar diaschisis and bright pulvinar in status epilepticus

Crossed cerebellar diaschisis and bright pulvinar are rare in patients with status epilepticus. We present a case of a 53-year-old man who was found confused, incontinent, and nonverbal. The EEG findings were consistent with non-convulsive status epilepticus. The brain MR images showed findings consistent with crossed cerebellar diaschisis and bright pulvinar. We report and discuss this case to increase the awareness of these MRI signs in confused and obtunded patients.

Very early hypothermia induction in patients with severe brain injury (the National Acute Brain Injury Study: Hypothermia II): a randomised trial

BACKGROUND

The inconsistent effect of hypothermia treatment on severe brain injury in previous trials might be because hypothermia was induced too late after injury. We aimed to assess whether very early induction of hypothermia improves outcome in patients with severe brain injury.

METHODS

The National Acute Brain Injury Study: Hypothermia II (NABIS: H II) was a randomised, multicentre clinical trial of patients with severe brain injury who were enrolled within 2·5 h of injury at six sites in the USA and Canada. Patients with non-penetrating brain injury who were 16-45 years old and were not responsive to instructions were randomly assigned (1:1) by a random number generator to hypothermia or normothermia. Patients randomly assigned to hypothermia were cooled to 35°C until their trauma assessment was completed. Patients who had none of a second set of exclusion criteria were either cooled to 33°C for 48 h and then gradually rewarmed or treated at normothermia, depending upon their initial treatment assignment. Investigators who assessed the outcome measures were masked to treatment allocation. The primary outcome was the Glasgow outcome scale score at 6 months. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, NCT00178711.

FINDINGS

Enrolment occurred from December, 2005, to June, 2009, when the trial was terminated for futility. Follow-up was from June, 2006, to December, 2009. 232 patients were initially randomised a mean of 1·6 h (SD 0·5) after injury: 119 to hypothermia and 113 to normothermia. 97 patients (52 in the hypothermia group and 45 in the normothermia group) did not meet any of the second set of exclusion criteria. The mean time to 35°C for the 52 patients in the hypothermia group was 2·6 h (SD 1·2) and to 33°C was 4·4 h (1·5). Outcome was poor (severe disability, vegetative state, or death) in 31 of 52 patients in the hypothermia group and 25 of 56 in the normothermia group (relative risk [RR] 1·08, 95% CI 0·76-1·53; p=0·67). 12 patients in the hypothermia group died compared with eight in the normothermia group (RR 1·30, 95% CI 0·58-2·52; p=0·52).

INTERPRETATION

This trial did not confirm the utility of hypothermia as a primary neuroprotective strategy in patients with severe traumatic brain injury.

Mutations in VLDLR as a cause for autosomal recessive cerebellar ataxia with mental retardation (dysequilibrium syndrome)

Dysequilibrium syndrome is a genetically heterogeneous condition that combines autosomal recessive, nonprogressive cerebellar ataxia with mental retardation. Here, we report the first patient heterozygous for 2 novel mutations in VLDLR. An 18-month-old girl presented with significant hypotonia, global developmental delay, and truncal and peripheral ataxia. Magnetic resonance imaging of the brain demonstrated hypoplasia of the inferior cerebellar vermis and hemispheres, small pons, and a simplified cortical sulcation pattern. Sequence analysis of the VLDLR gene identified a nonsense and missense mutation. Six mutations in VLDLR have now been identified in 5 families with a phenotype characterized by moderate-to-profound mental retardation, delayed ambulation, truncal and peripheral ataxia, and occasional seizures. Neuroanatomically, the loss-of-function effect of the different mutations is indistinguishable. VLDLR-associated cerebellar hypoplasia is emerging as a panethnic, clinically, and molecularly well-defined genetic syndrome.

MULTIFOCAL COMPLEX GLIONEURONAL TUMOR IN AN ELDERLY MAN

OBJECTIVE

The clinicopathological spectra of a dysembryoplastic neuroepithelial tumor (DNT) and a rosette-forming glioneuronal tumor (RGNT) are expanding. We report here the autopsy findings of a case of complex glioneuronal tumor with combined histological features of both a DNT and an RGNT.

CLINICAL PRESENTATION

A 79-year-old man presented with a 1-month history of confusion and gait difficulties. A magnetic resonance imaging scan revealed obstructive hydrocephalus attributed to a mass in the posterior third ventricle.

INTERVENTION

A third ventriculostomy was performed. Postoperatively, the mass remained unchanged in size for more than 14 months. Thirty-eight months after his initial manifestations, he experienced minor head trauma and was then hospitalized. Despite placement of an external ventricular drain and other supportive treatment, he deteriorated and died. A full autopsy was performed, with emphasis on the brain. The mass lesion and a few independent microfoci situated primarily around the third ventricle showed histological features of pilocytic astrocytoma with recurrent hemorrhage. Far more numerous were microfoci with histological features of a DNT, including floating neurons, as well as typical RGNT-associated, synaptophysin-positive rosettes and perivascular pseudorosettes.

CONCLUSION

The advanced age of the patient, the coexisting histological features of the DNT and RGNT, and the distinctive anatomic distribution of the lesions, being centered on the third ventricle, may lend insight into the histogenetic relationship of a DNT, an RGNT, and mixed glioneuronal tumors.

An improved scoring system for identifying patients at high early risk of stroke and functional impairment after an acute transient ischemic attack or minor stroke

BACKGROUND

Risk of a subsequent stroke following an acute transient ischemic attack (TIA) or minor stroke is high. The ABCD(2) tool was proposed as a method to triage these patients using five clinical factors. Modern imaging of the brain was not included. The present study quantified the added value of magnetic resonance imaging (MRI) factors to the ABCD(2) tool.

METHODS

Patients with TIA or minor stroke were examined within 12 h and had a brain MRI within 24 h of symptom onset. Primary outcomes were recurrent stroke and functional impairment at 90 days. A new tool, ABCD(2)+MRI, was created by adding diffusion-weighted imaging lesion and vessel occlusion status to the ABCD(2) tool. The predictive accuracy of both tools was quantified by the area under the curve (AUC).

RESULTS

One hundred and eighty patients were enrolled and 11.1% had a recurrent stroke within 90 days. The predictive accuracy of the ABCD(2)+MRI was significantly higher than ABCD(2) (AUC of 0.88 vs. 0.78, P=0.01). Those with a high score (7-9) had a 90-day recurrent stroke risk of 32.1%, moderate score (5-6) risk of 5.4%, and low score (0-4) risk of 0.0%. The ABCD(2) tool did not predict risk of functional impairment at 90 days (P=0.33), unlike the ABCD(2)+MRI (P=0.02): high score (22.9%), moderate (7.5%), low (7.7%).

CONCLUSIONS

Risk of recurrent stroke and functional impairment after a TIA or minor stroke can be accurately predicted by a scoring system that utilizes both clinical and MRI information. The ABCD(2)+MRI score is simple and its components are commonly available during the time of admission.

Meckel syndrome in the Hutterite population is actually a Joubert-related cerebello-oculo-renal syndrome

Meckel syndrome (MKS) is a rare lethal autosomal recessive disorder characterized by the presence of occipital encephalocele, cystic kidneys, fibrotic changes of the liver and polydactyly. Joubert syndrome (JS)-related disorders (JSRDs) or cerebello-oculo-renal syndromes (CORS) are a group of recessively inherited conditions characterized by a molar tooth sign (MTS) on cranial MRI, a set of core clinical features (developmental delay/mental retardation, hypotonia, ataxia, episodic breathing abnormalities, abnormal eye movements) and variable involvement of other systems including renal, ocular, central nervous system, craniofacial, hepatic, and skeletal. A significant clinical overlap between MKS and JSRD/CORS has been recognized in the literature. We describe a group of 10 Hutterite patients, of which 7 had been previously diagnosed with MKS, with a JSRD. Clinical features include variable early mortality, cognitive handicap, a characteristic dysmorphic facial appearance, hypotonia, ataxia, abnormal breathing pattern, nystagmus, and MTS on MRI. Additional features include occipital encephalocele, posterior fossa fluid collections resembling Dandy-Walker malformation, hydrocephalus, coloboma, and renal disease. This JSRD is a recognizable dysmorphic syndrome characterized by hypertelorism, deep-set eyes, down-slanting palpebral fissures, ptosis, arched eyebrows with medial sparseness, square nasal tip, short philtrum with tented upper lip, open mouth with down-turned corners, and posteriorly rotated low-set ears. Renal disease is present in 70% of patients and is characterized by cystic kidneys, abnormalities in renal function and hypertension. Homozygous deletions of NPHP1 and the known loci for JS/JSRD and MKS were excluded by identity-by-descent mapping studies suggesting that this condition in the Hutterites represents yet another locus for a JSRD.

3-Tesla versus 1.5-Tesla Magnetic Resonance Diffusion and Perfusion Imaging in Hyperacute Ischemic Stroke

BACKGROUND

Clinical 3-tesla magnetic resonance imaging systems are becoming widespread. No studies have examined differences between 1.5-tesla and 3-tesla imaging for the assessment of hyperacute ischemic stroke (<6 h from symptom onset). Our objective was to compare 1.5-tesla and 3-tesla diffusion and perfusion imaging for hyperacute stroke using optimized protocols.

METHODS

Three patients or their surrogate provided informed consent. Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) was performed sequentially at 1.5 T and 3 T. DWI, apparent diffusion coefficient (ADC) maps and relative time-to-peak (TTP) maps were registered and assessed. DWI contrast-to-noise ratio (CNR) and ADC contrast were measured and compared. The infarct lesion volume (ILV) and thresholded ischemic volume (TIV) were estimated on the ADC and TTP maps, respectively, with the penumbral volume being defined as the difference between these volumes.

RESULTS

Qualitatively, the 3-tesla TTP images exhibited greater feature detail. Quantitatively, the DWI CNR and ILV were similar at both field strengths, the ADC contrast was greater at 3 T and the TIV and penumbral volumes were much smaller at 3 T.

CONCLUSIONS

Overall, the 3-tesla diffusion and perfusion images were at least as good and in some ways superior to the 1.5-tesla images for assessing hyperacute stroke. The TTP maps showed greater feature detail at 3 T. The ischemic and penumbra volumes were much greater at 1.5 T, indicating a potential difference in the diagnostic utility of the PWI-DWI mismatch between field strengths.

Autosomal recessive cerebellar hypoplasia in the Hutterite population

Cerebellar hypoplasia is a rare malformation caused by a variety of etiologies. It usually manifests clinically as non-progressive cerebellar ataxia with or without mental retardation. We further characterize a syndrome of autosomal recessive cerebellar hypoplasia in the Hutterite population, referred to as dysequilibrium syndrome (DES). We reviewed 12 patients (eight females, four males; age range 4 to 33 y) with this syndrome. Patients were examined and underwent a standard set of investigations to characterize better the clinical features, natural history, and neuroimaging of this syndrome. DES is an autosomal recessive disorder with distinct clinical features including global developmental delay, late ambulation (after age 6 y), truncal ataxia, and a static clinical course. Neuroimaging is characterized by hypoplasia of the inferior portion of the cerebellar hemispheres and vermis, and mild simplification of cortical gyri.

Homozygous deletion of the very low density lipoprotein receptor gene causes autosomal recessive cerebellar hypoplasia with cerebral gyral simplification

An autosomal recessive syndrome of nonprogressive cerebellar ataxia and mental retardation is associated with inferior cerebellar hypoplasia and mild cerebral gyral simplification in the Hutterite population. An identity-by-descent mapping approach using eight patients from three interrelated Hutterite families localized the gene for this syndrome to chromosome region 9p24. Haplotype analysis identified familial and ancestral recombination events and refined the minimal region to a 2-Mb interval between markers D9S129 and D9S1871. A 199-kb homozygous deletion encompassing the entire very low density lipoprotein receptor (VLDLR) gene was present in all affected individuals. VLDLR is part of the reelin signaling pathway, which guides neuroblast migration in the cerebral cortex and cerebellum. To our knowledge, this syndrome represents the first human lipoprotein receptor malformation syndrome and the second human disease associated with a reelin pathway defect.

Diagnosis and outcome of psychiatric referrals to the Field Mental Health Team, 202 Field Hospital, Op Telic I

OBJECTIVES

To assess referrals to a Field Hospital Mental Health Team (FMHT), assign a diagnosis, provide appropriate treatment, and decide whether suitable for safe return to unit in theatre (RTU), or evacuation home on psychiatric grounds (evac).

METHODS

All documented referrals to the FMHT of 202 Field Hospital during the Op Telic 1 study period of 17 March (day 1) to 23 July 2003 (day 129) were included. Data were collected on rank, gender, diagnosis, outcome (whether RTU or evac), and whether TA before mobilisation. Diagnosis was assigned by ICD-10 criteria.

RESULTS

The FMHT documented 170 cases, 12 of whom were seen twice and one on three occasions, resulting in 184 referrals, all of whom were British. The commonest diagnosis was adjustment reaction (F43), accounting for 68% of all cases (n = 116). These were divided between chiefly theatre-related (n = 77) or chiefly home-related (n = 39) reactions. The majority (94%) of these cases were RTU. Referrals where the diagnosis was a Depressive disorder (F32, n = 23) or Intentional self-harm (by sharp object, X78, n = 7) were evacuated. Outcome was similar for Regular and TA personnel, with on average 72% of cases RTU. The majority of cases seen were ORs, reflecting their numbers in theatre. Only 14 NCOs and 14 officers were referred. Thirteen of the latter were TA before mobilisation. Gender was not associated with outcome, or TA status, but was associated with rank, in that significantly more female officers were referred. The FMHT role tasks emerged as (a) psychiatric triage and treatment, (b) psychological support of hospital staff, and (c) welfare and pastoral care liaison.

CONCLUSION

The utility of the psychiatric management model employed, built upon previous military medical doctrines, was tested in a modern theatre of conflict, and seemed to prove its worth.

Silent ischemia in minor stroke and TIA patients identified on MR imaging

BACKGROUND

In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical events, the authors examined whether patients with minor stroke and TIA also had a high rate of asymptomatic lesions on repeat MRI scanning.

METHODS

Patients with minor stroke and TIA presenting within 12 hours of symptom onset with a NIH Stroke Scale score less than six, who had a baseline MRI and a 1-month follow-up, were enrolled in this study. The follow-up study was examined for new diffusion-weighted imaging lesions as compared to the baseline study. Clinical or MRI factors predicting recurrent lesions were examined.

RESULTS

A total of 143 patients were enrolled and 14 patients (9.8%; 95% CI 5.4, 15.9) had MR evidence of new lesions at 30 days. Six of these new lesions were clinically asymptomatic (42.9%; 95% CI 17.7, 71.1). A trend to increased likelihood of new lesions at 30 days was seen with progressing baseline scan lesion number (none [2.2%], solitary [12.9%], multiple [19.8%]: p = 0.046). Patients whose mechanism of stroke was large artery or cardioembolic were the most likely to have new lesions on follow-up MRI.

CONCLUSION

Minor stroke and TIA are associated with a 10% risk of new lesions on MRI and half of these new lesions are asymptomatic. This risk is lower than seen in more severely affected patients with stroke. Patients with multiple lesions at baseline are at an increased risk for new ischemic lesions.

Surveillance of intracranial aneurysms treated with detachable coils: a comparison of MRA techniques

Two MRA techniques were evaluated for the follow-up of coiled intracranial aneurysms. Twenty-nine coiled aneurysms were evaluated for a total of 36 follow-up assessments using 3D time-of flight MRA (TOF MRA), an auto-triggered elliptic-centric-ordered three-dimensional gadolinium-enhanced MR angiogram (ATECO MRA), as well as a selective digital subtraction angiography (DSA), which served as the "gold standard". Confident visualization was seen in 36 (100%) of ATECO MRAs and in 32 (89%) of the TOF MRAs. Eleven residual aneurysm components (RACs) greater than 2 mm were described on DSA. Of these, nine were seen on ATECO MRA (sensitivity of 81% and specificity of 88%) and four were seen on TOF MRA (sensitivity of 40% and specificity of 90%). The two RACs not seen on ATECO MRA both measured 3 mm. The six RACs not seen on TOF MRA measured 3, 4 and 5 mm. ATECO MRA provides a non-invasive reliable angiogram for the surveillance of coiled aneurysms and is superior to TOF MRA for this purpose.

Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging

We examined whether the presence of diffusion-weighted imaging (DWI) lesions and vessel occlusion on acute brain magnetic resonance images of minor stroke and transient ischemic attack patients predicted the occurrence of subsequent stroke and functional outcome. 120 transient ischemic attack or minor stroke (National Institutes of Health Stroke Scale < or = 3) patients were prospectively enrolled. All were examined within 12 hours and had a magnetic resonance scan within 24 hours. Overall, the 90-day risk for recurrent stroke was 11.7%. Patients with a DWI lesion were at greater risk for having a subsequent stroke than patients without and risk was greatest in the presence of vessel occlusion and a DWI lesion. The 90-day risk rates, adjusted for baseline characteristics, were 4.3% (no DWI lesion), 10.8% (DWI lesion but no vessel occlusion), and 32.6% (DWI lesion and vessel occlusion) (p = 0.02). The percentages of patients who were functionally dependent at 90 days in the three groups were 1.9%, 6.2%, and 21.0%, respectively (p = 0.04). The presence of a DWI lesion and a vessel occlusion on a magnetic resonance image among patients presenting acutely with a transient ischemic attack or minor stroke is predictive of an increased risk for future stroke and functional dependence.

Growth-associated proteins and regeneration-induced gene expression in the aging neuron

Axonal elongation and sprouting during regeneration are retarded with aging but the etiology of this is unclear. We investigated whether this age-associated decline is related to a decline in expression of three different growth-associated proteins (GAPs): alpha(1)-tubulin, neurofilament (NF) light subunit (NF-L) and GAP-43. Northern analysis was performed on L4-L5 dorsal root ganglia (DRG) of young (3 months) and aged (23 months) rats following a sciatic nerve crush and compared to their age-matched controls. The results show that initial mRNA levels of alpha(1)-tubulin and NF-L in the control aged rat DRG were half those of the control young adults, whereas expression of GAP-43 was unchanged. Two weeks after axotomy, the expression of alpha(1)-tubulin and GAP-43 in the aged DRG was induced to the same levels as in the axotomized young adult, and the expression of NF-L decreased proportionately in both age groups. These results indicate that certain neuronal mRNAs, such as alpha(1)-tubulin and NF-L may be maintained at lower levels in aging DRG neurons, whereas others, such as GAP-43 appear to be unaltered. However, during regeneration, the aging DRG neuron appears capable of inducing alpha(1)-tubulin, NF-L and GAP-43 as well as the young adult.

Posterior fossa lesion volume and slowed information processing in multiple sclerosis

The relationship between performance on information processing efficiency measures and MRI-derived lesion volume including global and regional T2 and T1 lesion volumes was investigated in 20 patients with relapsing-remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS). Processing speed, as measured by the Sternberg Memory Scanning Test, was significantly correlated with posterior fossa lesion volume and slowed reaction time in seven out of eight patients (six out of seven with SPMS) with any lesion volume in the posterior fossa suggesting a 'threshold effect'. Processing capacity as measured by the Salthouse Keeping Track Test was not significantly correlated with the MRI measures. Cognitive performance did not correlate with Expanded Disability Status Scale score, depression or fatigue, and patients performed within normal limits on tests of attention/concentration ability. The significant relationship between posterior fossa lesion volume and memory scanning speed in this study suggests that pathological damage in the posterior fossa may contribute to slowed cognitive processing and may be an important direction for future studies of cognitive function in multiple sclerosis. Lack of correlation of cognitive measures with the other MRI measures may be due to low lesion volume relative to other studies, sample composition, and limited pathological specificity of the MRI measures.

Idiopathic intracranial hypertension: the prevalence and morphology of sinovenous stenosis

OBJECTIVE

To determine the prevalence and nature of sinovenous obstruction in idiopathic intracranial hypertension (IIH) using auto-triggered elliptic-centric-ordered three-dimensional gadolinium-enhanced MR venography (ATECO MRV).

METHODS

In a prospective controlled study, 29 patients with established IIH as well as 59 control patients underwent ATECO MRV. In a randomized blinded fashion, three readers evaluated the images. Using a novel scoring system, each reader graded the degree of stenosis seen in the transverse and sigmoid sinuses of each patient.

RESULTS

There was excellent agreement across the three readers for application of the grading system. Substantial bilateral sinovenous stenoses were seen in 27 of 29 patients with IIH and in only 4 of 59 control patients.

CONCLUSION

Using ATECO MRV and a novel grading system for quantifying sinovenous stenoses, the authors can identify IIH patients with sensitivity and specificity of 93%.

On-call services provided by radiology residents in a university hospital environment

OBJECTIVE

To better understand the consultative role of the radiology resident after hours.

METHODS

Data were collected prospectively from Mar. 15, 1999, to Jan. 5, 2001, during on-call coverage hours at our university hospital. Urgent radiologic examinations for which the on-call resident rendered a preliminary interpretation were included in our analysis, with the following entered into a database: patient demographics, consultative time and weekday, imaging modality, consulting clinical service and indication for each study.

RESULTS

A total of 1784 studies were performed on 1451 patients; most were requested by the emergency department (844 cases [47.3%]). The mean number of radiographic studies performed was 20.1 (standard error of the mean [SEM] 1.1) per weekday (n = 44) and 49.4 (SEM 1.8) per weekend day or holiday (n = 18). There were 1227 (68.8%) computed tomographic (CT), 338 (18.9%) ultrasonographic, 98 (5.5%) plain radiograph, 63 (3.5%) nuclear medicine, 21 (1.2%) interventional, 20 (1.1%) fluoroscopic and 17 (1.0%) magnetic resonance imaging examinations. The 3 most common studies were CT of the head in 692 cases, CT of the abdomen in 230 and venous Doppler ultrasonography in 158.

CONCLUSIONS

Radiology residents are performing a diverse and increasing number of emergent diagnostic examinations after hours. It is therefore important that radiology departments are aware of these consultative needs to best ensure that appropriate resident skills are developed to meet these demands.

Imaging and anatomy of the normal intracranial venous system

The intracranial venous system is a complex three-dimensional structure that is often asymmetric and considerably more variable than the arterial anatomy. The traditional approach has been to evaluate venous phase of catheter angiography. However, non-invasive imaging is now playing a greater role in evaluating the intracranial venous system in both healthy and diseased states. MR angiography, and especially Gd-enhanced 3D MRA, has recently emerged and offers excellent visualization of venous morphology from multiple orientations. An overview of the current non-invasive MRA methods and their applications has been provided during depiction of normal venous anatomy.

Intracranial venous system: gadolinium-enhanced three-dimensional MR venography with auto-triggered elliptic centric-ordered sequence--initial experience

PURPOSE

To evaluate gadolinium-enhanced three-dimensional auto-triggered elliptic centric-ordered (ATECO) magnetic resonance (MR) venography for imaging of the intracranial venous system.

MATERIALS AND METHODS

ATECO MR venography was performed in 23 patients, eight of whom also underwent two-dimensional time-of-flight (TOF) MR venography for imaging of the intracranial venous system. Seventeen predefined venous structures were evaluated on all venograms by two neuroradiologists. Visualization of venous structures was defined as completely visible (including clearly pathologic), partially visible, or not visible. Readers were also asked to compare the visibility of these predefined structures on ATECO and TOF MR venograms, where available.

RESULTS

Of the 23 patients, six had dural venous sinus disease. Of the remaining 17 healthy patients, five underwent both ATECO and TOF MR venography and 12 underwent ATECO MR venography alone. On ATECO MR venograms obtained in the healthy patients, visibility of the 17 predefined venous structures was complete in 92% (531 of 578) of evaluations. For the five normal TOF MR venograms, the rate of complete visibility of the same venous structures was 61% (104 of 170). The rate of complete visibility of the large dural venous sinuses was 99% for ATECO MR venograms and 75% for TOF MR venograms.

CONCLUSION

ATECO MR venography provides high-quality images of the intracranial venous anatomy and was superior to TOF MR venography for consistent complete visibility of venous structures.

How often are nonenhancing supratentorial gliomas malignant? A population study

The presence of contrast enhancement in a brain tumor is often regarded as a sign of malignancy. The authors identified 314 patients with malignant and low-grade supratentorial glial neoplasms in an unselected population, 58 of which lacked contrast enhancement on preoperative neuroimaging. Nonenhancing gliomas were malignant in approximately one third of cases, especially in older patients. Histologic confirmation of the diagnosis is therefore important in all patients suspected of harboring a primary glial neoplasm.

Determination of hexavalent chromium at the level of the California Public Health Goal by ion chromatography

Chromium is a primary drinking water contaminant in the USA with hexavalent chromium, Cr(VI), being the most toxic form of the metal. As a required step in developing a revised state drinking water standard for chromium, the California Department of Health Services recently issued a new Public Health Goal (PHG) of 2.5 microg/l for total chromium and 0.2 microg/l for Cr(VI). Hexavalent chromium can be determined (as chromate) by ion chromatography, as described in US Evironmental Protection Agency Method 218.6; however, the method as originally published does not allow sufficient sensitivity for analysis at the California PHG level of 0.2 microg/l. Modification of the conditions described in Method 218.6, including the use of a lower eluent flow-rate, larger reaction coil, and larger injection volume, significantly increases the method sensitivity. The modified method, which uses IonPac NG1 and AS7 guard and analytical columns, an eluent of 250 mM ammonium sulfate-100 mM ammonium hydroxide operated at 1.0 ml/min, a 1000 microl injection volume, and postcolumn reaction with 2 mM diphenylcarbazide-10% methanol-0.5 M sulfuric acid (using a 750 microl reaction coil) followed by UV-Vis detection at 530 nm, permits a method detection limit for chromate of 0.02 microg/l. This results in a quantitation limit of 0.06 microg/l, which is more than sufficient for analysis at the California PHG level. Calibration is linear over the range of 0.1-10 microg/l and quantitative recoveries (>80%) are obtained for chromate spiked at 0.2 microg/l in drinking water. The modified method provides acceptable performance, in terms of chromate peak shape and recovery, in the presence of up to 1000 mg/l chloride or 2000 mg/l sulfate.

Using QuickTime virtual reality objects in computer-assisted instruction of gross anatomy: Yorick--the VR Skull

QuickTime virtual reality (QTVR) is a software technology that creates, on a normal computer screen, the illusion of holding and turning a three-dimensional object. QTVR is a practical photo-realistic virtual reality technology that is easily implemented on any current personal computer or via the Internet with no special hardware requirements. Because of its ability to present dynamic photo-quality images, we reasoned that QTVR can provide a more realistic presentation of anatomic structure than two-dimensional atlas pictures and facilitate study of specimens outside the dissection lab. We created QTVR objects, using portions of the skull, and incorporated them into an instructional program for first-year medical students. To obtain images, the bones of the skull were mounted on a rotating table, and a digital camera was positioned on a swinging arm so that the focal point remained coincident with the rotational center of the object as the camera was panned through a vertical arc. Digital images were captured at intervals of 10 degrees rotation of the object (horizontal pan). The camera was then swung through an arc with additional horizontal pan sequences taken at 10 degrees intervals of vertical pan. The images were edited to place the object on a solid black background, then assembled into a linear QuickTime movie. The linear movie was processed to yield a QTVR object movie that can be manipulated on vertical and horizontal axes using the mouse. QTVR movies were incorporated into an interactive environment that provided labeling, links to text-based information and self-testing capabilities. This program, Yorick-the VR Skull, has been used in our first-year medical and graduate gross anatomy courses for the past two years. Results of student evaluation of the program indicate that this QTVR-based program is an effective learning tool that is well received by students.

Neurofilament and tubulin gene expression in progressive experimental diabetes: failure of synthesis and export by sensory neurons

In human and experimental diabetes, the relationship between molecular abnormalities in perikarya of sensory neurons and structural abnormalities in their distal axons is largely unexplored. In this study we examined neurofilament (Nf) and tubulin messenger RNA (mRNA) expression and their incorporation into distal sensory axons during progressive streptozotocin-induced diabetes in rats. After 2 and 6 months of diabetes, we measured mRNA levels of all three Nf subunits, B50 [growth associated protein-43 (GAP-43)] and alpha-tubulin in L4-L6 dorsal root ganglia using Northern analysis. The same animals underwent morphometric studies of myelinated fibres by light microscopy and quantitative analysis of Nf and microtubule numbers and density within sural myelinated and unmyelinated axons. Multifibre in vivo sensory and motor conduction nerve recordings confirmed slowing of conduction velocities in diabetic rats indicating experimental neuropathy. mRNA levels for the three Nf subunits, B50 (GAP-43) and alpha-tubulin were unchanged from controls at 2 months, but were decreased by 26-46% at 6 months. These changes accompanied declines in Nf numbers and densities within large myelinated sensory axons, and Nf numbers in unmyelinated fibres by 6 months. Microtubule numbers and densities were similarly reduced in large myelinated axons, and microtubule numbers reduced in small myelinated and unmyelinated axons in diabetes at 6, but not 2 months. Axonal atrophy was observed in unmyelinated fibres at 6 months. Our findings indicate that decreased mRNA expression of cytoskeletal proteins in sensory neurons accompanies a reduction in their incorporation into distal axons. These changes imply that there is a direct link between pathological changes in the sensory neuron and alterations of its distal branches from experimental diabetes. The changes in gene expression in diabetes are unique and differ from those that develop after axotomy.

Which glioblastoma multiforme patient will become a long-term survivor? A population-based study

In this clinical and histopathological study, the frequency of long-term glioblastoma multiforme (GBM) survivors (LTGBMSs) was determined in a population-based study. The Alberta Cancer Registry was used to identify all patients diagnosed with GBM in Alberta between January 1, 1975, and December 31, 1991. Patient charts were reviewed and histology reexamined. LTGBMSs were defined as GBM patients surviving 3 years after diagnosis. Each LTGBMS was compared with 3 age-, sex-, and year of diagnosis-matched controls, and patient/treatment or tumor characteristics that predicted long-term survival were determined. There were 689 GBMs diagnosed in the study period; 15 (2.2%) of these patients survived 3 years. LTGBMSs (average age, 43.5 +/- 3.3 years) were significantly younger when compared with all GBM patients (average age, 53.0 +/- 0.56 years). LTGBMSs had a higher Karnofsky Performance Status score at diagnosis compared with controls. LTGBMSs were much more likely to have had a gross total resection and adjuvant chemotherapy than control GBM patients. Tumors from LTGBMSs tended to have fewer mitoses and a significantly lower Ki-67 cellular proliferation index compared with controls. Radiation-induced dementia was common and disabling in LTG-BMSs. In conclusion, conventionally treated GBM patients in an unselected population have a very small chance of long-term survival. The use of aggressive surgical resection and adjuvant chemotherapy may make long-term survival more likely in GBM patients if their performance status is high at diagnosis.