External validation of a pharmacokinetic model for target-controlled infusion of cefazolin as a prophylactic antibiotic

AIMS

This study aimed to evaluate the predictive performance of previously constructed cefazolin pharmacokinetic models and determine whether cefazolin administration via the target-controlled infusion (TCI) method may be possible in clinical practice.

METHODS

Twenty-five gastrectomy patients receiving cefazolin as a prophylactic antibiotic were enrolled. Two grams of cefazolin was dissolved in 50 mL of normal saline to give a concentration of 40 mg mL-1 . Before skin incision, cefazolin was administered using a TCI syringe pump, and its administration continued until the end of surgery. The target total plasma concentration was set to 100 μg mL-1 . Total and unbound plasma concentrations of cefazolin were measured in three arterial blood samples collected at 30, 60 and 120 min after the start of cefazolin administration. The predictive performance of the TCI system was evaluated using four measures: inaccuracy, divergence, bias and wobble.

RESULTS

Total (n = 75) and unbound (n = 75) plasma concentration measurements from 25 patients were included in the analysis. The pooled median (95% confidence interval) biases and inaccuracies were 6.3 (4.0-8.5) and 10.5 (8.6-12.4) for the total concentration model and -10.3 (-16.8 to -3.7) and 22.4 (18.2-26.7) for the unbound concentration model, respectively. All unbound concentrations were above 10 μg mL-1 .

CONCLUSION

Administration of cefazolin by the TCI method showed a clinically acceptable performance. Applying the TCI method by setting the total concentration as the target concentration rather than the unbound concentration is effective in maintaining a constant target concentration of cefazolin.

Geometric parameters on MRA source images to differentiate small Proximal Posterior communicating artery aneurysms from Infundibular dilation

BACKGROUND AND PURPOSE

We aimed to assess the accuracy of magnetic resonance angiography (MRA) in the differentiation of small aneurysms versus infundibular dilations (IDs) at the internal carotid artery-posterior communicating artery (ICA-PComA) junction, emphasizing the role of MRA axial source images.

METHODS

This retrospective study consisted of 83 focal arterial protrusions at ICA-PComA junction in 76 patients who underwent both MRA and digital subtraction angiography (DSA)/3-dimensional rotational angiography (3DRA). The diagnostic performance of MRA for differential diagnosis of aneurysm from ID was calculated using DSA/3DRA interpretation as the standard of reference. In addition, long-axis diameter, short-axis diameter, long-axis diameter/short-axis diameter (L/S) ratio, and angle of lesion (angle of the long-axis of lesion with respect to the x-axis) measured on MRA source images were compared between aneurysms and IDs.

RESULTS

Sensitivity, specificity, and accuracy of MRA for distinguishing aneurysms from IDs were 74.4% (57.9-87.0%) to 76.9% (60.7-88.9%), 93.2% (81.3-98.6%) to 95.5% (84.5-99.4%), and 85.5% (76.1-92.3%), respectively. Significant differences were found for the long-axis diameter (P < .001), short-axis diameter (P < .001), L/S ratio (P < .05), and angle of the lesion (P < .001) on MRA axial source images between aneurysms and IDs. The angle of the lesion had the highest discriminatory ability (area under the curve = .966 [.902-.994]) to differentiate aneurysms from IDs. An angle of lesion >60° was 89.7% (75.8-97.1%) sensitive and 100% (92.0-100.0%) specific for diagnosis of aneurysm.

CONCLUSIONS

MRA is a useful imaging modality for distinguishing between aneurysm and ID at the ICA-PComA junction. Furthermore, geometric parameters on MRA axial source images can provide added value in their differentiation.

256-row multislice CT angiography in the postoperative evaluation of cerebral aneurysms treated with titanium clips: using three-dimensional rotational angiography as the standard of reference

OBJECTIVE

To assess the diagnostic accuracy of 256-row multislice computed tomographic angiography (CTA) compared with three-dimensional rotational angiography (3DRA) in the postoperative evaluation of cerebral aneurysms treated with titanium clips.

METHODS

A total of 128 patients (42 men, 86 women; mean age, 57.6 years) with 143 cerebral aneurysms treated using titanium clips underwent both CTA and 3DRA. Two reviewers retrospectively evaluated the following parameters on CTA and 3DRA: (1) residual/recurrent aneurysm (absent or present), (2) patency of parent artery (patent or occluded/severe stenotic (> 70%)), and (3) patency of adjacent branch (patent or occluded/absent).

RESULTS

A total of 24 residual/recurrent aneurysms were detected by 3DRA. The sensitivity, specificity, and accuracy of CTA for the detection of residual/recurrent aneurysms were 83.3%, 100%, and 97.2% for reviewer 1 and 79.2%, 100%, and 96.5% for reviewer 2, respectively. The sensitivity, specificity, and accuracy of CTA for the evaluation of patency of parent artery were 100%, 100%, and 100%, respectively, for both reviewers. The sensitivity, specificity, and accuracy of CTA for evaluation of the patency of adjacent branch were 85.1%, 100%, and 92.3% for reviewer 1 and 82.4%, 100%, and 90.9% for reviewer 2, respectively.

CONCLUSION

A 256-row multislice CTA is a valuable non-invasive tool for assessment of cerebral aneurysms treated with titanium clips.

KEY POINTS

• A 256-row multislice CTA is an accurate imaging technique for the postoperative assessment of cerebral aneurysms treated with titanium clips. • Sensitivity of CTA for the detection of residual/recurrent aneurysms was 79-83% compared with 3DRA. • CTA is still limited in detecting residual/recurrent aneurysms of < 2 mm and small adjacent branches.

A hybrid operating room for combined surgical and endovascular procedures for cerebrovascular diseases: a clinical experience at a single centre

Purpose: To describe our experiences with a fully equipped high-end digital subtraction angiography (DSA) system within a hybrid operating room (OR). Material and methods: A single-plane DSA system with 3-dimensional rotational angiography (3DRA), cone-beam computed tomography, and real-time navigation software was used in our hybrid OR. Between April 2014 and January 2018, 191 sessions of neurovascular procedures were performed in our hybrid OR. After the retrospective review of all cases, the procedures were categorised into five subcategorical procedures according to the dominance of surgical and/or endovascular procedures: intraoperative angiographic evaluation, combined endovascular and surgical procedure, complementary rescue procedure during intervention and surgery, surgical approach for interventional procedure, and frameless stereotaxic operation. Results: Intraoperative angiography revealed unsatisfactory clipping of intracranial aneurysms in 6 (13.6%) patients and remnant AVMs in 1 (16.7%) patient, which were determined as complete surgical outcome via indocyanine green videoangiography. Four cases of blood blister aneurysms and a ruptured posterior inferior cerebellar artery aneurysm were treated using bypass surgery and endovascular trapping. Eight cases of ruptured aneurysm with intracranial haemorrhage (ICH) were treated by partial embolisation and surgical clipping. Two (5.4%) of the 37 cases of pre-mature rupture during clipping were secured by endovascular coil embolisation. In 1 (0.8%) complicated case of 103 intra-arterial (IA) thrombectomy procedures, emergency surgical embolectomy with bypass surgery was performed. Direct puncture of the common carotid artery or vertebral artery was performed to achieve interventional access to treat aneurysm or recanalise vessel occlusions in 7 cases. In 27 cases of ICH, frameless stereotaxic haematoma aspiration was performed using XperGuide® system. All procedures were performed in single sessions without any procedural complications. Conclusion: Hybrid OR with a fully equipped DSA system could provide safe and precise treatment for neurovascular diseases. Hybrid procedures for neurovascular diseases in hybrid OR are a promising new trend.

Four-Year Experience Using an Advanced Interdisciplinary Hybrid Operating Room : Potentials in Treatment of Cerebrovascular Disease

Objective

To describe our experiences with a fully equipped high-end digital subtraction angiography (DSA) system within a hybrid operating room (OR).

Methods

A single-plane DSA system with 3-dimensional rotational angiography, cone-beam computed tomography (CBCT), and real-time navigation software was used in our hybrid OR. Between April 2014 and January 2018, 191 sessions of cerebrovascular procedures were performed in our hybrid OR. After the retrospective review of all cases, the procedures were categorized into three subcategorical procedures : combined endovascular and surgical procedure, complementary rescue procedure during intervention and surgery, and frameless stereotaxic operation.

Results

Forty-nine of 191 procedures were performed using hybrid techniques. Four cases of blood blister aneurysms and a ruptured posterior inferior cerebellar artery aneurysm were treated using bypass surgery and endovascular trapping. Eight cases of ruptured aneurysm with intracranial hemorrhage (ICH) were treated by partial embolization and surgical clipping. Six cases of ruptured arteriovenous malformation with ICH were treated by Onyx embolization of nidus and subsequent surgical removal of nidus and ICH. Two (5.4%) of the 37 cases of pre-mature rupture during clipping were secured by endovascular coil embolization. In one (0.8%) complicated case of 103 intra-arterial thrombectomy procedures, emergency surgical embolectomy with bypass surgery was performed. In 27 cases of ICH, frameless stereotaxic hematoma aspiration was performed using XperGuide^® system (Philips Medical Systems, Best, the Netherlands). All procedures were performed in single sessions without any procedural complications.

Conclusion

Hybrid OR with a fully equipped DSA system could provide precise and safe treatment strategies for cerebrovascular diseases. Especially, we could suggest a strategy to cope flexibly in complex lesions or unexpected situations in hybrid OR. CBCT with real-time navigation software could augment the usefulness of hybrid OR.

The most mentioned neurointervention articles in online media: a bibliometric analysis of the top 101 articles with the highest altmetric attention scores

Background and purpose

Alternative metrics (altmetrics), based on mentions in online media, is a new tool that can help to identify the most influential articles to diverse public audiences. This article aimed to determine the 100 most mentioned articles in the field of neurointervention and to analyze their characteristics.

Materials and methods

We selected the 808 journals that were considered journals potentially publishing articles on neurointervention. We also selected articles using keywords. Using the Altmetric.com search tool, we identified the 101 most mentioned neurointervention articles based on the highest altmetric attention scores (AASs) within selected journals and articles. Each article was evaluated for several characteristics including AAS, number of citations, journal title, journal category, impact factor of the journal, year of publication, authorship, country, type of document, and topic.

Results

The AASs for the top 101 articles ranged from 1586 to 39. Stroke published the largest number of articles (19.8%) followed by the New England Journal of Medicine (17.8%). The majority of articles were published in multidisciplinary journals (38.6%), were published in 2017–2018 (43.6%), originated from the USA (54.5%), were original articles (66.3%), and dealt with intra-arterial thrombolysis or thrombectomy for acute ischemic stroke (58.4%). Tudor G Jovin was the most prolific author, authoring 18 of the most mentioned neurointervention articles

Conclusions

This study presents a detailed list of the 101 most mentioned neurointervention articles in online media, thus providing useful information on the dissemination of neurointervention research to the general public.

Endovascular Coiling for a Wide-neck Bifurcated Aneurysm with Anterograde Horizontal Stenting via Microcatheter Looping: A Technical Case Report

Technical advances with devices such as catheters, balloons, and stents have widened the indications for endovascular coiling for unfavorable aneurysms. The authors report two cases of coil embolization for a wide-neck bifurcated aneurysm with anterograde horizontal stenting via microcatheter looping. Two women, aged 56 and 38 years, respectively, had an undertall- and overwide-neck aneurysm with bifurcated branches at the basilar bifurcation and middle cerebral bifurcation, respectively. The delivery microcatheter was steamed so that it could be looped deliberately to the opposite vessel. The enterprise stent was first anchored to the vessel of the posterior cerebral artery on one side. The remaining portion was spanned into a looped microcatheter to the opposite branch while pushing the stent. The Neuroform Atlas stent was passed directly through the looped segment of the microcatheter at the M2 branch and spanned horizontally by unsheathing. Under horizontal stenting, complete coil embolization was achieved without immediate or delayed complications in both cases. This novel technique presents a viable option for stent-assisted coiling within an optimal anatomy.

Intraobserver and interobserver variability in CT angiography and MR angiography measurements of the size of cerebral aneurysms

PURPOSE

Accurate and reliable measurement of aneurysm size is important for treatment planning. The purpose of this study was to determine intraobserver and interobserver variability of CTA and MRA for measurement of the size of cerebral aneurysms.

METHODS

Thirty patients with 33 unruptured cerebral aneurysms (saccular, >3 mm in their maximal dimension, with no daughter sacs or lobulations) who underwent 256-row multislice CTA, 3-D TOF MRA at 3.0T, and 3D rotational angiography (3DRA) were retrospectively analyzed. Three independent observers measured the neck, height, and width of the aneurysms using the CTA and MRA images. Intraobserver and interobserver variability of CTA and MRA measurements was evaluated using the standardized difference and intraclass correlation coefficient, with 3DRA measurements as the reference standard. In addition, the mean values of the measurements using CTA and MRA were compared with those using 3DRA.

RESULTS

The overall intraobserver and interobserver standardized differences in CTA/MRA were 12.83-15.92%/13.48-17.45% and 14.08-17.00%/12.08-17.67%, respectively. The overall intraobserver and interobserver intraclass correlation coefficients of CTA/MRA were 0.88-0.98/0.84-0.96 and 0.86-0.98/0.85-0.95, respectively. Compared to the height and width measurements, measurements of the neck dimensions showed higher intraobserver and interobserver variability. The sizes of the cerebral aneurysms measured by CTA and MRA were 1.13-9.26 and 5.20-9.67% larger than those measured by 3DRA, respectively; however, these differences were not statistically significant.

CONCLUSION

There were no noticeable differences between intraobserver and interobserver variability for both CTA- and MRA-based measurements of the size of cerebral aneurysms.

Citation classics in neurointerventional research: a bibliometric analysis of the 100 most cited articles

BACKGROUND AND PURPOSE

The number of citations that an article has received can be used to evaluate its impact on the scientific community. This study aimed to identify the 100 most cited articles in the field of neurointervention and to analyze their characteristics.

MATERIALS AND METHODS

We selected the 669 journals that were considered potentially to publish neurointervention articles based on the database of Journal Citation Reports. Using the Web of Science citation search tool, we identified the 100 most cited articles relevant to neurointervention within the selected journals. Each article was evaluated for several characteristics including publication year, journal, journal category, impact factor, number of citations, number of citations per year, authorship, department, institution, country, type of article, and topic.

RESULTS

The number of citations for the top 100 articles ranged from 1912 to 170 (mean 363.4) and citations per year ranged from 271.0 to 4.1 (mean 40.0). The majority of articles were published in clinical neurology journals (63%), were published in 2000-2009 (39%), originated in the USA (45%), were original articles (95%), and dealt with endovascular treatment of cerebral aneurysm (42%). The Department of Radiology, University of California School of Medicine (n=12) was the leading institution and Viñuela F (n=11) was the most prolific author.

CONCLUSIONS

Our study presents a detailed list and analysis of the 100 most cited articles in the field of neurointervention and provides a historical perspective on the scientific progress in this field.

Vertigo and nystagmus in orthostatic hypotension

BACKGROUND AND PURPOSE

Generalized cerebral ischaemia from cardiovascular dysfunction usually leads to presyncopal dizziness, but several studies reported a higher frequency of rotatory vertigo in cardiovascular patients. Whether generalized cerebral ischaemia due to cardiovascular disorders may produce objective vestibular dysfunction was investigated.

METHODS

Thirty-three patients with orthostatic dizziness/vertigo due to profound orthostatic hypotension and 30 controls were recruited. All participants underwent recording of eye movements during two orthostatic challenging tests: the Schellong and the squatting-standing tests. Most patients had neuroimaging, and patients with abnormal eye movements were subjected to follow-up evaluations.

RESULTS

Symptoms associated with orthostatic dizziness/vertigo included blurred vision, fainting and tinnitus. Ten (30%) of 33 patients developed rotatory vertigo and nystagmus during the Schellong (n = 5) or squatting-standing test (n = 5). Four of them showed pure downbeat nystagmus whilst five had downbeat and horizontal nystagmus with or without torsional component. Patients with orthostatic nystagmus had shorter duration of orthostatic intolerance than those without nystagmus (1.0 ± 1.6 vs. 11.0 ± 9.7 months, P < 0.001). In two patients, orthostatic nystagmus disappeared during follow-up despite the persistence of profound orthostatic hypotension.

CONCLUSIONS

Generalized cerebral ischaemia caused by orthostatic hypotension induces rotatory vertigo due to objective vestibular dysfunction. The presence of orthostatic vertigo and nystagmus has an association with the duration of orthostatic intolerance.

Delayed improvement after endoscopic carpal tunnel release

OBJECTIVE

In most patients with carpal tunnel syndrome (CTS), pain and/or paresthesia disappeared or decreased in a month after endoscopic carpal tunnel release (ECTR). However, subpopulation of patients showed delayed improvement following ECTR. We analyzed the delayed improvement hands to investigate the characteristics of those patients and to determine the predictable factors of delayed improvement.

METHODS

Single-portal ECTRs were performed in 1194 hands of 793 CTS patients from 2002 to 2011. Five-hundred seventy hands with minimal 1-year postoperative follow-up were included. We divided the 545 satisfied hands into early (group A) and delayed (group B) groups according to improvement period of 1 month. Demographic data, clinical severity and electrodiagnostic abnormality were compared between groups.

RESULTS

Group A included 510 hands and group B included 35 hands. In group B, 11 hands improved in 2 months, 15 hands in 3 months and 9 hands in 6 months, respectively. In group A/B, according to clinical severity, 60/1 hands were graded to I, 345/24 hands to II, 105/10 hands to III. In group A/B, based on electrodiagnostic abnormality, 57/3 hands were classified to mild, 221/11 hands to moderate and 222/21 hands to severe group. Statistical analysis between groups did not reach significance but electrodiagnostic or clinical severity had a tendency to affect the delayed response.

CONCLUSION

It is difficult to predict the factors contributing to postoperatively-delayed response in subpopulation of CTS patients. However, we recommend that postoperative observation for at least 6 months is necessary in patients without symptomatic improvement.

Neurointerventional research between 2003 and 2012: slow growth, high interdisciplinary collaboration, and a low level of funding

BACKGROUND AND PURPOSE

Neurointerventional therapy of cerebrovascular disease is a greatly expanding field across many specialty disciplines. The goal of this study was to analyze the characteristics and trends of scientific publications that focused on neurointervention during the past decade.

MATERIALS AND METHODS

A bibliometric evaluation of neurointerventional research published between 2003 and 2012 was conducted by using the PubMed data base. Analyzed parameters included the year of publication, type of document, language of the article, topic, declared funding, country of origin, type of collaboration between disciplines, the first author's specialty, and subject category and the Impact Factor of the publishing journal.

RESULTS

Between 2003 and 2012, a total of 2123 articles were published, of which 1107 (52.1%) were original articles, 1948 (91.8%) were written in English, 192 (9.0%) received funding, 661 (31.1%) were published by the United States, and 1060 (49.9%) resulted from interdisciplinary collaboration. Neurosurgery departments produced the most articles (n = 910, 42.9%), followed by radiology (n = 747, 35.2%) and neurology (n = 270, 12.7%). The time-trend analysis in the number of publications demonstrated slow growth from 2003 to 2012, with an average annual growth rate of +6.0%.

CONCLUSIONS

The fields of neurosurgery, radiology, and neurology have contributed substantially to neurointervention research. Slow growth, high interdisciplinary collaboration, and a low level of funding are peculiar characteristics of research in this field.

Clinical and radiological spectrum of posterior reversible encephalopathy syndrome

OBJECTIVE

Symptoms of posterior reversible encephalopathy syndrome (PRES) include headache, altered mental status, visual disturbances, and seizures. Typical radiological features include edema of the parieto-occipital lobes. The purpose of this study is to review the clinical and radiological findings in patients diagnosed with PRES.

METHODS

All patients diagnosed with PRES between January 2006 and December 2012 were retrospectively included in this study. We reviewed demographic and clinical characteristics, and radiological findings.

RESULTS

We identified 16 patients with PRES. The most common clinical presentation was seizure (n = 12, 75%). Clinical recovery occurred in all patients within days (mean, 5.7 ± 4.6 days). Comorbid conditions included hypertension (n = 4, 25%), cytotoxic medications (n = 3, 18.8%), sepsis (n = 4, 25%), malignancy (n = 4, 25%), subarachnoid hemorrhage (n = 1, 6.3%), autoimmune disorders (n = 1, 6.3%) and eclampsia (n = 1, 6.3%). The most commonly involved location was the parieto-occipital lobe (n = 13, 81.3%). Atypical radiological findings included significant basal ganglia involvement in 4 episodes; brainstem in 3, cerebellum in 2, and thalamus in 3. Eleven patients (68.8%) underwent diffusion-weighted imaging and apparent diffusion coefficient mapping. Of those, 9 patients (81.8%) had hypo- or isointensity on diffusion-weighted imaging. On the apparent diffusion coefficient map, 10 patients (90.9%) had hyperintensity, and the other had normal values.

CONCLUSION

We suggest that PRES may occur in patients with complex systemic conditions. The prognosis of PRES is usually benign. Physicians should be aware of certain atypical radiological findings to avoid a delayed diagnosis of PRES, as delayed diagnosis and treatment can result in permanent neurological sequlae.

Accuracy of CT angiography in the assessment of the circle of Willis: comparison of volume-rendered images and digital subtraction angiography

BACKGROUND

Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases.

PURPOSE

To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis.

MATERIAL AND METHODS

One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard).

RESULTS

The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%.

CONCLUSION

CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments.

Unilateral extrapedicular vertebroplasty and kyphoplasty in lumbar compression fractures : technique, anatomy and preliminary results

OBJECTIVE

A single balloon extrapedicular kyphoplasty has been introduced as one of the unilateral approaches for thoracic compression fractures; however, the unilateral extrapedicular technique in the lumbar area needs a further understanding of structures in the lumbar area. The purpose of the present study is to describe methods and pitfalls of this procedure based on the anatomy of the lumbar area and to analyze clinical outcome and complications.

METHODS

Anatomical evaluation was performed with 2 human cadavers. A retrospective review of unilateral extrapedicular approaches yielded 74 vertebral levels in 55 patients that were treated with unilateral extrapedicular vertebroplasty and kyphoplasty. Radiographic assessment included the restoration rate of vertebral height and correction of kyphosis.

RESULTS

Anatomical evaluation indicates that the safe needle entry zone of bone for the extrapedicular approach was located in the supero-lateral aspect of the junction between the pedicle and vertebral body. The unilateral extrapedicular procedure achieved adequate pain relief with a mean decreases in pain severity of 7.25±1.5 and 2.0±1.4, respectively. Complications were 1 retroperitoneal hematoma, 6 unilateral fillings and 3 epidural leak of the polymethylmethacrylate.

CONCLUSION

The method of a unilateral extrapedicular approach in kyphoplasty and vertebroplasty in the lumbar area might be similar to that in thoracic approach using a route via the extrapedicular space. However, different anatomical characteristics of the lumbar area should be considered.

Imaging features of intradural spinal paragonimiasis: a case report

Spinal paragonimiasis is a rare form of ectopic infestation caused by Paragonimus westermani. We report a case of pathologically proven intradural paragonimiasis associated with concurrent intracranial involvement. MRI revealed multiple well-defined intradural masses that were markedly hypointense on T(2) weighted images and hypointense with a peripheral hyperintense rim on T(1) weighted images. Contrast-enhanced T(1) weighted images showed slight peripheral rim enhancement.

Efficacy of low dose barbiturate coma therapy for the patients with intractable intracranial hypertension using the bispectral index monitoring

OBJECTIVE

Barbiturate coma therapy (BCT) is a useful method to control increased intracranial pressure (IICP) patients. However, the complications such as hypotension and hypokalemia have caused conditions that stopped BCT early. The complications of low dose BCT with Bispectral index (BIS) monitoring and those of high dose BCT without BIS monitoring have been compared to evaluate the efficacy of low dose BCT with BIS monitoring.

METHODS

We analyzed 39 patients with high dose BCT group (21 patients) and low dose BCT group (18 patients). Because BIS value of 40-60 is general anesthesia score, we have adjusted the target dose of thiopental to maintain the BIS score of 40-60. Therefore, dose of thiopental was kept 1.3 to 2.6 mg/kg/hour during low dose BCT. However, high dose BCT consisted of 5 mg/kg/hour without BIS monitoing.

RESULTS

The protocol of BCT was successful in 72.2% and 38.1% of low dose and high dose BCT groups, respectively. The complications such as QT prolongation, hypotension and cardiac arrest have caused conditions that stopped BCT early. Hypokalemia showed the highest incidence rate in complications of both BCT. The descent in potassium level were 0.63 +/- 0.26 in low dose group, and 1.31 +/- 0.48 in high dose group. The treatment durations were 4.89 +/- 1.68 days and 3.38 +/- 1.24 days in low dose BCT and high dose BCT, respectively.

CONCLUSION

It was proved that low dose BCT showed less severe complications than high dose BCT. Low dose BCT with BIS monitoring provided enough duration of BCT possible to control ICP.

Lumbosacral plexopathy, complicating rhabdomyolysis in a 57-year-old man, presented with sudden weakness in both legs

A 57-year-old man presented with weakness in both legs upon awakening after drinking. Magnetic resonance imaging (MRI) of the lumbar spine did not reveal any intraspinal abnormalities but MRI of the pelvis revealed lesions with abnormal intensities with heterogeneous contrast enhancement in both gluteal muscles. Serum creatine phosphokinase was markedly elevated. A diagnosis of lumbosacral plexopathy, complicating rhabdomyolysis was made. With supportive care he recovered well but mild weakness of the right ankle remained at 6 month-follow-up. Pelvic MRI is a helpful diagnostic tool in localizing rhabdomyolysis. Lumbosacral plexopathy should be included in the differential diagnosis of the such cases, presenting with sudden weakness of legs.

A mouse model of intracerebral hemorrhage using autologous blood infusion

The development of controllable and reproducible animal models of intracerebral hemorrhage (ICH) is essential for the systematic study of the pathophysiology and treatment of hemorrhagic stroke. In recent years, we have used a modified version of a murine ICH model to inject blood into mouse basal ganglia. According to our protocol, autologous blood is stereotactically infused in two stages into the right striatum to mimic the natural events of hemorrhagic stroke. Following ICH induction, animals demonstrate reproducible hematomas, brain edema formation and marked neurological deficits. Our technique has proven to be a reliable and reproducible means of creating ICH in mice in a number of acute and chronic studies. We believe that our model will serve as an ideal paradigm for investigating the complex pathophysiology of hemorrhagic stroke. The protocol for establishing this model takes about 2 h.

Surgical experience of the ruptured distal anterior cerebral artery aneurysms

OBJECTIVE

Distal anterior cerebral artery (DACA) aneurysms are fragile and known to have high risks for intraoperative premature rupture and a relatively high associated morbidity. To improve surgical outcomes of DACA aneurysms, we reviewed our surgical strategy and its results postoperatively.

METHODS

A total of 845 patients with ruptured cerebral aneurysms were operated in our hospital from January 1991 to December 2005. Twenty-three of 845 patients had ruptured DACA aneurysms which were operated on according to our surgical strategy. Our surgical strategy was as follows; early surgery, appropriate releasing of CSF, appropriate surgical approach, using neuronavigating system, securing the bridging veins, using temporary clipping and/or tentative clipping, meticulous manipulation of aneurysm, and using micro-Doppler flow probe. Twenty of 23 patients who had complete medical records were studied retrospectively. We observed the postoperative radiographic findings and checked Glasgow Outcome Scale score sixth months after the operation.

RESULTS

Nineteen DACA aneurysms were clipped through a unilateral interhemispheric approach and one DACA aneurysm was clipped through a pterional approach. Postoperative radiographic findings revealed complete clipping of aneurysmal neck without stenosis or occlusion of parent arteries. In two patients, a residual neck of aneurysm was visualized. Seventeen patients showed good recovery, one patient resulted in moderate disability, while 2 patients died.

CONCLUSION

With our surgical strategy it was possible to achieve acceptable surgical morbidity and mortality rates in patients with DACA aneurysms. Appropriate use of tentative clipping, temporary clipping and neuro-navigating systems can give great help for safe approach and clipping of DACA aneurysm.

Delayed diagnosis of cerebellar hemangioblastoma after intracerebellar hemorrhage

BACKGROUND

Cerebellar hemorrhage caused by cerebellar hemangioblastoma is not a frequent case. We report a case of solid, cerebellar hemangioblastoma, diagnosed 4 years after cerebellar hemorrhage.

CASE DESCRIPTION

A 69-year-old man presented with dizziness and gait disturbance. He had a 4-year history of evacuation of cerebellar hemorrhage. Gadolinium-enhanced MRI revealed a well-enhancing mass in the left cerebellar hemisphere, and vertebral angiography revealed hypervascularity. Radiotherapy was given to the tumor bed. He remained stable for more than a year after radiation.

CONCLUSION

In cases of spontaneous cerebellar hemorrhage, particularly in the patient without hypertension or other underlying diseases related to bleeding from tumor, cerebellar hemangioblastoma should be suspected as a rare cause of hemorrhage, and computed tomography and/or MRI with contrast administration is mandatory for differential diagnosis.

Detection and characterization of intracranial aneurysms with 16-channel multidetector row CT angiography: a prospective comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE

The aim of our study was to compare multidetector row CT angiography (MDCTA) with digital subtraction angiography (DSA) in the detection and characterization of intracranial aneurysms.

MATERIALS AND METHODS

In our blinded prospective study, 85 patients with suspected intracranial aneurysm (47 women, 38 men; age range, 19-83 years) underwent both 16-channel MDCTA and DSA. The MDCT angiograms were interpreted for the presence, location, size, ratio of the neck to the dome (N/D ratio), and lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques. MDCTA and DSA images (reference standard) were interpreted by 2 independent readers, and the results were compared.

RESULTS

A total of 93 aneurysms were detected at DSA in 71 patients, whereas no aneurysms were detected in 14 patients. Compared with DSA, the overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 92.5%, 93.3%, and 92.6%, respectively, for both independent readers. For aneurysms of <3 mm, however, MDCTA had a sensitivity of 74.1% for reader 1 and 77.8% for reader 2. There was excellent agreement between readers in the detection of aneurysms (kappa = 0.822). In addition, MDCTA was also accurate in determining N/D ratio of aneurysms, aneurysm lobularity, and adjacent arterial branches.

CONCLUSION

MDCTA is accurate in the detection and characterization of intracranial aneurysms and can be used as a reliable alternative imaging technique to DSA in selected cases.

Differences in corneal thickness and corneal endothelium related to duration in diabetes

PURPOSE

This study evaluated the differences of corneal thickness and corneal endothelial morphology in diabetes compared with age-matched, healthy control subjects; in addition, we tested for correlation according to the duration of diabetes.

METHODS

Ultrasound pachymetry and noncontact specular microscopy were performed on 200 patients with diabetes and 100 control subjects. We compared the values for diabetics and normal persons with ANACOVA to adjust for age. Moreover, we examined the correlation between the subject parameters and the duration of diabetes by using a partial correlation coefficient that controlled for age.

RESULTS

The diabetic subjects had thicker corneas, less cell density and hexagonality, and more irregular cell size of the corneal endothelium than did the controls (P < 0.05). Central corneal thickness and the coefficient of variation for cell size were significantly higher for diabetes of over 10 years' duration than for diabetes of under 10 years' duration (P < 0.05). The endothelial cell density and percentage of hexagonal cells were lower for diabetes of over 10 years' duration than for diabetes of under 10 years' (P > 0.05). Central corneal thickness was correlated with duration of diabetes (P < 0.05), but corneal endothelial morphology was not (P < 0.05).

CONCLUSIONS

Those patients with diabetic duration of over 10 years have more corneal morphological abnormalities, especially the coefficient of variation in cell size, compared with the normal subjects. The central corneal thickness was significantly correlated with diabetic duration after controlling for age.

The study of cerebral hemodynamics in the hyperacute stage of fat embolism induced by triolein emulsion

PURPOSE

The purpose of this study was to evaluate the cerebral hemodynamic change in the hyperacute stage of cerebral fat embolism induced by triolein emulsion, by using MR perfusion imaging in cat brains.

METHODS

By using the femoral arterial approach, the internal carotid arteries of 14 cats were infused with an emulsion of triolein 0.05 mL. T2-weighted (T2WI), diffusion-weighted (DWI), apparent diffusion coefficient (ADC) map, perfusion-weighted (PWI), and gadolinium-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 30 minutes and 2, 4, and 6 hours after infusion. The MR images were evaluated qualitatively and quantitatively. Qualitative evaluation was performed by assessing the signal intensity of the serial MR images. Quantitative assessment was performed by comparing the signal-intensity ratio (SIR) of the lesions to the contralateral normal side calculated on T2WIs, Gd-T1WIs, DWIs, and ADC maps at each acquisition time and by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (CBF), and mean transit times (MTT) of the lesions to the contralateral normal side calculated on PWI.

RESULTS

In the qualitative evaluation of the MR images, the lesions showed hyperintensity on T2WIs, enhancement on the Gd-T1WIs, and isointensity on DWIs and the ADC maps. In the quantitative studies, SIRs on the Gd-T1WIs, DWIs, and ADC maps peaked at 2 hours after infusion. The SIRs on the T2WIs peaked at 4 hours after infusion and decreased thereafter. On PWIs, the rCBV, rCBF, and MTT of the lesion showed no significant difference from the contralateral normal side (P = .09, .30, and .13, respectively) and showed no significant change of time course (P = .17, .31, and .66, respectively).

CONCLUSION

The embolized lesions induced by triolein emulsion showed no significant difference in cerebral hemodynamic parameters from those on the contralateral normal side. The result may suggest that consideration of the hemodynamic factor of embolized lesions is not necessary in further studies of the blood-brain barrier with triolein emulsion.

Surgical Outcome of Endoscopic Carpal Tunnel Release in 100 Patients with Carpal Tunnel Syndrome

The purpose of this study is to present the surgical outcome of endoscopic carpal tunnel release (ECTR) for the treatment of carpal tunnel syndrome (CTS). One hundred and thirty-one procedures (36 right hands, 33 left hands and 31 bilateral hands) of single portal ECTR were performed upon 100 patients (age range: 36-77 years, mean age: 52.9 years; 98 women and 2 men) with electrodiagnostically proven CTS for 2.5 years from 2001. Preoperative clinical severity and results of electrodiagnostic studies were compared with surgical outcomes at the minimal 3-month postoperative period. Among 131 cases 125 (95.4 %) with complete or significant relief of symptoms were satisfied and 6 (4.6 %) with partial or no relief of symptoms were dissatisfied. There were 2 cases of major complications (one with ulnar nerve injury and the other with ulnar artery injury) that developed in our early experience of ECTR and 1 case of recurrence. The grade of electrodiagnostic abnormalities was associated with surgical outcome but there was no statistical significance between them. The severity of clinical findings, age at onset and symptom duration were not correlated with surgical outcome. In conclusion, ECTR surgery was effective in relieving the symptoms of CTS with a low complication rate after the learning curve period. Thus, ECTR can be an alternative to the traditional open surgery and can be the first procedure for CTS with several advantages over open methods.

Head injuries from falls in preschool children

Falls are a leading cause of morbidity and mortality among children. We performed a retrospective analysis of pediatric patients under 7 years of age admitted to our department after a fall from January 1994 through December 1999 to describe the characteristics of fall-related head injury and to determine the clinical parameters influencing outcome. The patients were divided into two groups according to age: group I (babies and toddlers, 0-3 years) and group II (preschool children, 4-6 years). Falls were classified as low and high level. Sixty-eight cases were identified and falls accounted for 35.2% of head injuries. There were more boys than girls, and more low-level falls(LLF) than high-level falls (HLF), particularly in group I. Although more common in HLF, significant intracranial injuries were also sustained from LLF. Calvarial fractures were the most frequent type of head injury and were more common in LLF than HLF. Admission Glasgow Coma Scale score, types of head injury and hypoxia on admission were significantly correlated with Glasgow Outcome Scale score, but age, sex, extracranial injury and height of fall did not influence clinical outcome. From this study, we concluded that the height of fall should not limit the evaluation of patients and that aggressive management is mandatory to improve outcome even in patients with poor prognostic factors.

Early development of vasogenic edema in experimental cerebral fat embolism in cats: correlation with MRI and electron microscopic findings

RATIONALE AND OBJECTIVES

To evaluate the magnetic resonance imaging and electron microscopic findings of the hyperacute stage of cerebral fat embolism in cats and the time needed for the development of vasogenic edema.

METHODS

Magnetic resonance imaging was performed at 30 minutes (group 1, n = 9) and at 30 minutes and 1, 2, 4, and 6 hours after embolization with triolein (group 2, n = 10). As a control for group 2, the same acquisition was obtained after embolization with polyvinyl alcohol particles (group 3, n = 5). Magnetic resonance images were analyzed qualitatively and quantitatively. Electron microscopic examination was done in all cats.

RESULTS

In group 1, the lesions were iso- or slightly hyperintense on T2-weighted (T2W) and diffusion-weighted (DWIs) images, hypointense on the apparent diffusion coefficient (ADC) map image, and markedly enhanced on the gadolinium-enhanced T1-weighted images (Gd-T1WIs). In group 2 at 30 minutes, the lesions were similar to those in group 1. Thereafter, the lesions became more hyperintense on T2WIs and DWIs and more hypointense on the ADC map image. The lesions were enhanced on Gd-T1WIs at all acquisition times. In group 3, the lesions showed mild hyperintensity on T2WIs at 6 hours but hypointensity on the ADC map image from 30 minutes, with a tendency toward a greater decrease over time. The lesions were not enhanced on Gd-T1WIs at any time point. Electron microscopic findings revealed discontinuity of the capillary endothelial wall, perivascular and interstitial edema, and swelling of glial and neuronal cells in groups 1 and 2. Cellular swelling and interstitial edema were more prominent in group 2. In group 3, interstitial edema was seen; however, discontinuity of the endothelial wall was absent.

CONCLUSIONS

The lesions were hyperintense on T2WIs and DWIs, hypointense on the ADC map image, and enhanced on Gd-T1WIs. On electron microscopy, the lesions showed cytotoxic and vasogenic edema with disruption of the blood-brain barrier. Vasogenic edema seems to develop within 30 minutes in cerebral fat embolism in cats.

A comparative study of corneal endothelial changes induced by different durations of soft contact lens wear

PURPOSE

To analyze the effect on the morphologic characteristics of the corneal endothelium of the duration of soft contact lens wearing periods.

METHODS

Ninety soft contact lens wearers were divided into three groups: short-term users, for less than 5 years (n=60 eyes); intermediate-term users, from 6 years to 10 years (n=60); longterm users, for more than 10 years (n=60). Thirty non-contact lens wearers (60 eyes) were included as controls. All eyes were examined with a specular microscope. Analysis of covariance was used to detect any differences among the controls and the various soft contact lens subgroups.

RESULTS

There was a significant correlation between duration of soft contact lens use and morphologic changes of corneal endothelium. All soft contact lens subgroups had a significantly greater coefficient of variation in cell size than non-contact lens users . The proportion of hexagonal cells and the mean corneal endothelial cell density in those using soft contact lenses for more than 6 years were significantly lower than in the control group . Soft contact lens wear was significantly correlated with decreasing corneal endothelial cell densities with time.

CONCLUSION

The coefficient of variation in cell size may be a sensitive indicator of early morphologic changes of the corneal endothelium. As the decrease in cell density among the contact lens subgroups was significantly associated with the duration of soft contact lens wearing periods, it will be useful to investigate endothelial cell density for evaluation of corneal endothelial function concerned with contact lens wearing.

A brief review of epidemiological studies on ischemic heart disease in Japan

The age-adjusted death rate from ischemic heart disease in Japan is the lowest among developed countries and the rates have decreased since 1970. The incidences of myocardial infarction in selected populations ranged between 0.12 and 2.56 per 1,000 for middle-aged males, and between 0.00 and 1.52 per 1,000 for females. The incidences of sudden death within 24 hours were from 0.00 to 1.58 per 1,000 for males and from 0.00 to 0.76 per/1,000 for females. The incidences in Japanese populations appeared to be far below those in Western populations. In the Cox proportional hazard regression model, hypertension and smoking were selected as independent risk factors for myocardial infarction in an agricultural district. It was noteworthy that the level of serum cholesterol was not associated with development of myocardial infarction in rural areas. No positive relation between dietary fat and serum cholesterol was observed in school children, suggesting that growth, sexual maturation and others might be confounding variables between them. The levels of serum cholesterol for females were more affected by menopause than those of blood pressures and body mass index. Although some polymorphisms in selected candidate genes appeared to be associated with some serum lipids and apolipoproteins, the effect of individual RFLP on the inter-individual variations in serum traits was relatively subtle in comparison with that of lifestyle factors.