Unexpected shunt-dependent hydrocephalus after unruptured aneurysm surgery-a case report

A chronic hydrocephalus after unruptured aneurysm surgery is an extremely rare condition. Its etiology and pathophysiology are also unclear. We report a case of chronic hydrocephalus in a patient who underwent permanent shunt placement after unruptured aneurysm clipping surgery. A 65-year-old man developed chronic hydrocephalus requiring shunt placement after clipping surgery of left anterior cerebral artery aneurysm and right middle cerebral artery aneurysm. This case shows that chronic hydrocephalus is a possible complication of unruptured aneurysm surgery, which can be resolved with an appropriate shunt operation.

Frictional force analysis of stent retriever devices using a realistic vascular model: Pilot study

Objective

To date, no vascular model to analyze frictional forces between stent retriever devices and vessel walls has been designed to be similar to the real human vasculature. We developed a novel in vitro intracranial cerebrovascular model and analyzed frictional forces of three stent retriever devices.

Methods

A vascular mold was created based on digital subtraction angiography of a patient's cerebral vessels. The vascular model was constructed using polydimethylsiloxane (PDMS, Dow Corning, Inc.) as a silicone elastomer. The vascular model was coated on its inner surface with a lubricating layer to create a low coefficient of friction (~0.037) to closely approximate the intima. A pulsatile blood pump was used to produce blood flow inside the model to approximate real vascular conditions. The frictional forces of Trevo XP, Solitaire 2, and Eric 4 were analyzed for initial and maximal friction retrieval forces using this vascular model. The total pulling energy generated during the 3 cm movement was also obtained.

Results

Results for initial retrieval force were as follows: Trevo, 0.09 ± 0.04 N; Solitaire, 0.25 ± 0.07 N; and Eric, 0.33 ± 0.21 N. Results for maximal retrieval force were as follows: Trevo, 0.36 ± 0.07 N; Solitaire, 0.54 ± 0.06 N; and Eric, 0.80 ± 0.13 N. Total pulling energy (N·cm) was 0.40 ± 0.10 in Trevo, 0.65 ± 0.10 in Solitaire, and 0.87 ± 0.14 in Eric, respectively.

Conclusions

Using a realistic vascular model, different stent retriever devices were shown to have statistically different frictional forces. Future studies using a realistic vascular model are warranted to assess SRT devices.

Discrepancy between MRA and DSA in identifying the shape of small intracranial aneurysms

OBJECTIVE

The authors evaluated the sensitivity and accuracy of MRA in identifying the shape of small-sized unruptured intracranial aneurysms.

METHODS

Small (< 7 mm) unruptured intracranial aneurysms initially detected by MRA and confirmed by DSA between January 2017 and December 2018 were morphologically reviewed by neuroradiologists. Regularity or irregularity of aneurysm shape was analyzed by two independent reviewers using MRA without DSA results. DSA findings served as the reference standard for aneurysm shape. Irregular shape, which in small aneurysms is associated with a higher likelihood of rupture, was defined as positive, and MRA sensitivity, specificity, and accuracy were determined by using evaluations based on location, size, and MRA magnetic strength (1.5T vs 3T MRA). Multivariate analysis was performed to determine risk factors for false-negative MRA results for irregularly shaped aneurysms.

RESULTS

In total, 652 unruptured intracranial aneurysms in 530 patients were reviewed for this study. For detecting aneurysm shape irregularity, the overall MRA sensitivity was 60.4% for reviewer 1 and 60.9% for reviewer 2. Anterior cerebral artery aneurysms had the lowest sensitivity for location (36.7% for reviewer 1, 46.9% for reviewer 2); aneurysms sized < 3 mm had the lowest sensitivity for size (26.7% for both reviewers); and 1.5T MRA had lower sensitivity and accuracy than 3T MRA. In multivariate analysis, location, size, and magnetic strength of MRA were independent risk factors for false-negative MRA results for irregularly shaped aneurysms.

CONCLUSIONS

MRA had a low sensitivity for detecting the irregular shape of small intracranial aneurysms. In particular, anterior cerebral artery location, aneurysm size < 3 mm, and detection with 1.5T MRA were associated with a higher risk of irregularly shaped aneurysms being misjudged as regular.

Clinical usefulness of deep learning-based automated segmentation in intracranial hemorrhage

BACKGROUND

Doctors with various specializations and experience order brain computed tomography (CT) to rule out intracranial hemorrhage (ICH). Advanced artificial intelligence (AI) can discriminate subtypes of ICH with high accuracy.

OBJECTIVE

The purpose of this study was to investigate the clinical usefulness of AI in ICH detection for doctors across a variety of specialties and backgrounds.

METHODS

A total of 5702 patients' brain CTs were used to develop a cascaded deep-learning-based automated segmentation algorithm (CDLA). A total of 38 doctors were recruited for testing and categorized into nine groups. Diagnostic time and accuracy were evaluated for doctors with and without assistance from the CDLA.

RESULTS

The CDLA in the validation set for differential diagnoses among a negative finding and five subtypes of ICH revealed an AUC of 0.966 (95% CI, 0.955-0.977). Specific doctor groups, such as interns, internal medicine, pediatrics, and emergency junior residents, showed significant improvement with assistance from the CDLA (p= 0.029). However, the CDLA did not show a reduction in the mean diagnostic time.

CONCLUSIONS

Even though the CDLA may not reduce diagnostic time for ICH detection, unlike our expectation, it can play a role in improving diagnostic accuracy in specific doctor groups.

Advantage of Balloon Guide Catheter During Endovascular Treatment of Direct Carotid-Cavernous Sinus Fistula: Technical Note and Report of 2 Cases

BACKGROUND

As previous studies reported, the balloon guide catheter is useful for identifying the fistula point during diagnosis of direct carotid-cavernous sinus fistula (d-CCF). We demonstrate an additional advantage of the balloon guide catheter during intraarterial endovascular treatment of d-CCF.

METHODS

Two cases of d-CCF are presented in this report. A balloon guide catheter is used to help achieve successful coil embolization of the fistula in both cases.

RESULTS

Microcatheter positioning into the fistulous point can be easier after balloon inflation. Balloon inflation can help with coil deployment.

CONCLUSIONS

Using a balloon guiding catheter can reduce internal carotid artery flow near the fistula point at the cavernous segment of the internal carotid artery. As a result, better identification of the fistula point can be made, which allows easier placement of the microcatheter into the fistula point and more stable coil deployment.

Prolonged SARS-CoV-2 detection and reversed RT-PCR results in mild or asymptomatic patients

BACKGROUND

The clinical course and viral detection period in mild or asymptomatic coronavirus disease 2019 (COVID-19) patients are not yet known. The presumed low diagnostic sensitivity of upper respiratory specimens for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) makes it difficult to confirm infection and recommend de-isolation.

METHODS

We retrospectively reviewed real-time reverse transcriptase-polymerase chain reaction (RT-PCR) test results of mild or asymptomatic COVID-19 patients who were admitted at the Daegu-Gyeongbuk 7th community treatment centre in Korea between 9 March 2020 and 10 April 2020. Patients underwent an upper respiratory RT-PCR test every week until discharge. From the RT-PCR results, we evaluated the rate of prolonged (>3 weeks) SARS-CoV-2 RNA positivity. We analysed the proportion of reversed results, defined as a positive or indeterminate result one day after a negative RT-PCR result, according to time (<14, 15-21, 22-28, >28 days) from the initial positive RT-PCR result.

RESULTS

In 23% (69/300) of patients, SARS-CoV-2 was detected more than 3 weeks after the initial positive RT-PCR. In 14% (42/300) of patients, the RT-PCR results were positive for more than 4 weeks. For 37.5% (152/405) of negative RT-PCR results, the results were reversed in the next day's test. And 43.5% (123/283) of negative RT-PCR results were reversed within 3 weeks of diagnosis.

CONCLUSIONS

The detection of SARS-CoV-2 lasting more than 3 weeks was common in mild or asymptomatic patients. Upper respiratory RT-PCR results were frequently reversed from negative to positive.

Pterional versus superciliary keyhole approach: direct comparison of approach-related complaints and satisfaction in the same patient

OBJECTIVE The objective of this study was to evaluate and compare the level of patient satisfaction and approach-related patient complaints between a superciliary keyhole approach and a pterional approach. METHODS Patients who underwent an ipsilateral superciliary keyhole approach and a contralateral pterional approach for bilateral intracranial aneurysms during an 11-year period were contacted and asked to complete a patient satisfaction questionnaire. The questionnaire covered 5 complaint areas related to the surgical approaches: craniotomy-related pain, sensory symptoms in the head, cosmetic complaints, palpable cranial irregularities, and limited mouth opening. The patients were asked to rate the 5 complaint areas on a scale from 0 (asymptomatic or very pleasant) to 4 (severely symptomatic or very unpleasant). Finally, the patients were asked to rate the level of overall satisfaction related to each surgical procedure on a visual analog scale (VAS) from 0 (most unsatisfactory) to 100 (most satisfactory). RESULTS A total of 21 patients completed the patient satisfaction questionnaire during a follow-up clinic visit. For the superciliary procedures, no craniotomy-related pain, palpable irregularities, or limited mouth opening was reported, and only minor sensory symptoms (numbness in the forehead) and cosmetic complaints (short linear operative scar) were reported (score = 1) by 1 (4.8%) and 3 patients (14.3%), respectively. Compared with the pterional approach, the superciliary approach showed better outcomes regarding the incidence of craniotomy-related pain, cosmetic complaints, and palpable irregularities, with a significant between-approach difference (p < 0.05). Furthermore, the VAS score for patient satisfaction was significantly higher for the superciliary approach (mean 95.2 ± 6.0 [SD], range 80-100) than for the pterional approach (mean 71.4 ± 10.6, range 50-90). Moreover, for the pterional approach, a multiple linear regression analysis indicated that the crucial factors decreasing the level of patient satisfaction were cosmetic complaints, craniotomy-related pain, and sensory symptoms, in order of importance (p < 0.05). CONCLUSIONS In successful cases in which the primary surgical goal of complete aneurysm clipping without postoperative complications is achieved, a superciliary keyhole approach provides a much higher level of patient satisfaction than a pterional approach, despite a facial wound. For a pterional approach, the patient satisfaction level is affected by the cosmetic results, craniotomy-related pain, and numbness behind the hairline, in order of importance.

Maximum Decompressive Hemicraniectomy for Patients with Malignant Hemispheric Infarction

Objective

The authors applied maximum external decompression for malignant hemispheric infarction and investigated the functional outcome according to the patient age.

Methods

Twenty-five patients with malignant hemispheric infarction were treated using a hemicraniectomy with maximum external decompression, comprising a larger (>14cm) hemicraniectomy, resection of the temporalis muscle and its fascia, spaciously expansive duraplasty, and approximation of the skin flap. The medical and diagnostic imaging records for the patients were reviewed, and 1-year functional outcome data obtained for the younger group (aged ≤ 60 years) and elderly group (aged > 60 years).

Results

The patients (n=25) who underwent maximum surgical decompression revealed a minimal mortality rate (n=2, 8.0%). The patients (n=14) in the younger group all survived with mRS scores of 2 (n=1, 7.1%), 3 (n=7, 50.0%), 4 (n=3, 21.4%), or 5 (n=3, 21.4%). A majority of the younger patients (57.1% with mRS ≤3) lived with functional independence. When the 1-year mRS scores were dichotomized between favorable (mRS ≤3) and unfavorable (mRS ≥4) outcomes, the younger group had significantly more patients with a favorable outcome than the elderly group (57.1% versus 9.1%, p=0.033). In contrast, in the elderly group, most patients showed unfavorable outcomes with the mRS scores of 4 (n=5, 45.5%), 5 (n=3, 27.3%), or 6 (n=2, 18.2%), whereas only one patient showed favorable outcome (mRS 3). A majority of the elderly patients (45.5% with mRS 4) survived with moderately severe disability.

Conclusion

For malignant hemispheric infarction, a hemicraniectomy with maximum external decompression was found to considerably increase survival with a favorable outcome in functional independence (mRS ≤3) for younger patients aged ≤60 years. It can be optimal surgical treatment for younger patients.

Should Cerebral Angiography Be Avoided within Three Hours after Subarachnoid Hemorrhage?

Objective

While the risk of aneurysmal rebleeding induced by catheter cerebral angiography is a serious concern and can delay angiography for a few hours after a subarachnoid hemorrhage (SAH), current angiographic technology and techniques have been much improved. Therefore, this study investigated the risk of aneurysmal rebleeding when using a recent angiographic technique immediately after SAH.

Methods

Patients with acute SAH underwent immediate catheter angiography on admission. A four-vessel examination was conducted using a biplane digital subtraction angiography (DSA) system that applied a low injection rate and small volume of a diluted contrast, along with appropriate control of hypertension. Intra-angiographic aneurysmal rebleeding was diagnosed in cases of extravasation of the contrast medium during angiography or increased intracranial bleeding evident in flat-panel detector computed tomography scans.

Results

In-hospital recurrent hemorrhages before definitive treatment to obliterate the ruptured aneurysm occurred in 11 of 266 patients (4.1%). Following a univariate analysis, a multivariate analysis using a logistic regression analysis revealed that modified Fisher grade 4 was a statistically significant risk factor for an in-hospital recurrent hemorrhage (p =0.032). Cerebral angiography after SAH was performed on 88 patients ≤3 hours, 74 patients between 3–6 hours, and 104 patients >6 hours. None of the time intervals showed any cases of intra-angiographic rebleeding. Moreover, even though the DSA ≤3 hours group included more patients with a poor clinical grade and modified Fisher grade 4, no case of aneurysmal rebleeding occurred during erebral angiography.

Conclusion

Despite the high risk of aneurysmal rebleeding within a few hours after SAH, emergency cerebral angiography after SAH can be acceptable without increasing the risk of intra-angiographic rebleeding when using current angiographic techniques and equipment.

Rare Case of Absent Common Carotid Artery Likely Associated with Intracranial Aneurysm Development

Congenital absence of the common carotid artery without separate origin of internal carotid artery and external carotid artery from the aortic arch is a very rare anomaly. A persistent proatlantal intersegmental artery into adult life is also a rare condition. We report a patient with the coexistence of such rare conditions who presented with cerebral infarctions and intracranial aneurysms.

Adjustable Ghajar Guide Technique for Accurate Placement of Ventricular Catheters: A Pilot Study

Objective

An adjustable Ghajar guide is presented to improve the accuracy of the original Ghajar guide technique. The accuracy of the adjustable Ghajar guide technique is also investigated.

Methods

The coronal adjustment angle from the orthogonal catheter trajectory at Kocher’s point is determined based on coronal head images using an electronic picture archiving and communication system. For the adjustable Ghajar guide, a protractor is mounted on a C-shaped basal plate that is placed in contact with the margin of a burrhole, keeping the central 0° line of the protractor orthogonal to the calvarial surface. A catheter guide, which is moved along the protractor and fixed at the pre-determined adjustment angle, is then used to guide the ventricular catheter into the frontal horn adjacent to the foramen of Monro. The adjustable Ghajar guide technique was applied to 20 patients, while a freehand technique based on the surface anatomy of the head was applied to another 47 patients. The accuracy of the ventricular catheter placement was then evaluated using postoperative computed tomography scans.

Results

For the adjustable Ghajar guide technique (AGT) patients, the bicaudate index ranged from 0.23 to 0.33 (mean±standard deviation [SD]: 0.27±0.03) and the adjustment angle ranged from 0° to 10° (mean±SD: 5.2°±3.2°). All the AGT patients experienced successful cerebrospinal fluid diversion with only one pass of the catheter. Optimal placement of the ventricular catheter in the ipsilateral frontal horn approximating the foramen of Monro (grade 1) was achieved in 19 patients (95.0%), while a suboptimal trajectory into a lateral corner of the frontal horn passing along a lateral wall of the frontal horn (grade 3) occurred in 1 patient (5.0%). Thus, the AGT patients experienced a significantly higher incidence of optimal catheter placement than the freehand catheterized patients (95.0% vs. 68.3%, p=0.024). Moreover, none of the AGT patients experienced any tract hemorrhages along the catheter or procedure-related complications.

Conclusion

The proposed adjustable Ghajar guide technique, using angular adjustment in the coronal plane from the orthogonal trajectory at Kocher’s point, facilitates accurate freehand placement of a ventricular catheter for hydrocephalic patients.

Striatal denervation pattern predicts levodopa effects on sequence learning in Parkinson's disease

Mild to moderate Parkinson's disease shows more denervation in the posterodorsal striatum and sparing of the anteroventral striatum. Dopaminergic medications can interfere with anteroventral striatum function by overdosing this relatively intact structure. The authors determined how regional striatal denervation affects medication-associated sequence learning impairment in Parkinson's disease. Eighteen Parkinson's patients performed motor sequence learning on and off levodopa. Patients underwent (11)C-dihydrotetrabenazine positron emission tomography scans to measure nigrostriatal denervation. Patients with more preserved putamen were more likely to exhibit levodopa-associated sequence learning impairments. Furthermore, the ratio of denervation in the anterior to posterior dorsal putamen predicted the level of learning differences on and off levodopa. These results demonstrate that the spatial pattern of nigrostriatal dopaminergic denervation predicts medication responsiveness for motor sequence learning.

Task-dependent interactions between dopamine D2 receptor polymorphisms and L-DOPA in patients with Parkinson's disease

Variants in genes regulating dopamine transmission affect performance on tasks including working memory and executive function as well as temporal processing and sequence learning. In the current study, we determined whether a dopamine D2 receptor DNA sequence polymorphism interacts with L-DOPA during motor tasks in patients with Parkinson's disease (PD). Forty-five PD patients were genotyped for the DRD2 polymorphism (rs 1076560, G>T). Patients performed an explicit motor sequence learning task and the grooved pegboard test in both ON and OFF L-DOPA states. For motor sequence learning, DRD2 genotype mediated L-DOPA effects such that L-DOPA associated improvements were only observed in the minor T allele carriers (associated with lower D2 receptor availability, t10=-2.71, p=0.022), whereas G homozygotes showed no performance change with L-DOPA. For the grooved pegboard test, performance improved with L-DOPA independent of patients' DRD2 genotype. Collectively these results demonstrate that common DRD2 allelic differences found in the human population may explain how dopamine differentially contributes to performance across tasks and individuals.

L-DOPA changes spontaneous low-frequency BOLD signal oscillations in Parkinson's disease: a resting state fMRI study

Analysis of the amplitude of low frequency BOLD signal fluctuations (ALFF) in the resting state has recently been used to study the dynamics of intrinsic neural activity. Several studies have also suggested its potential as a biomarker for neuropsychiatric disease. In the current study, we quantified ALFF to determine changes in intrinsic neural oscillations in patients with Parkinson's disease (PD) on and off L-DOPA. Twenty-four PD patients and 24 healthy age-matched controls participated in the study. PD patients underwent two resting state fMRI sessions, either ON a controlled dose of L-DOPA or following a placebo pill (OFF). Control participants underwent one test session. We found that there was increased amplitude of low frequency BOLD signal oscillations for PD patients OFF L-DOPA in the primary and secondary motor areas, and in the middle and medial prefrontal cortices. L-DOPA significantly reduced the amplitude of low frequency oscillations within these regions. The degree of ALFF in the premotor cortex predicted patients' motor performance as measured by the Grooved Pegboard task, such that greater ALFF was associated with poorer performance. These results are in line with the pathophysiology of PD, which shows changes in neural oscillations. Thus, frequency domain analyses of resting state BOLD fMRI signals may provide a useful means to study the pathophysiology of PD and the physiology of the brain's dopaminergic pathways.

Blockade of p38 mitogen-activated protein kinase pathway inhibits interleukin-6 release and expression in primary neonatal cardiomyocytes

The induction of interleukin-6 (IL-6) using combined proinflammatory agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) was studied in relation to p38 mitogen-activated protein kinase (MAPK) and NF-kappaB transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents (LPS/IFN-gamma or TNF-alpha/IFN-gamma) had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, IFN-gamma enhancement of TNF-alpha-induced NF-kappaB binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on TNF-alpha/IFN-gamma or LPS/IFN-gamma-induced NF-kappaB activation. This study strongly suggests that these pathways about TNF-alpha/IFN-gamma or LPS/IFN-gamma-activated IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

Antifungal susceptibility testing of Candida species by flow cytometry

The feasibility of flow cytometric antifungal susceptibility testing has been studied using the fluorescent anionic membrane potential probe, bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)]. The in vitro antifungal susceptibility testing of amphotericin B was performed on 8 Candida isolates from clinical specimens and 2 ATCC strains by flow cytometry with the results compared to those of the National Committee of Clinical Laboratory Standards (NCCLS) M27-T, broth macrodilution method. The flow cytometric method is based on an increase of fluorescence given out by DiBAC4(3) in fungi when they are killed by antifungal agents. Minimum inhibitory concentration (MIC) of amphotericin B ranged from 0.25 to 1 microg/mL. All results agreed within +/-2 dilution between the flow cytometric method and the M27-T method. MIC with ATCC strains were within recommended ranges of M27-T. The new flow cytometric method revealed a clear and distinct reproducible test end point. A four hr of incubation was sufficient for the test. In conclusion, flow cytometry using DiBAC4(3) is a rapid and accurate in vitro antifungal susceptibility testing method.