Secondary normal pressure hydrocephalus following pituitary apoplexy: A case report.

Background: Although secondary normal pressure hydrocephalus (sNPH) can occur in various central nervous system diseases, there are no reports of sNPH caused by pituitary lesions. Herein, we present a unique case of sNPH caused by pituitary apoplexy. Case Description: A 70-year-old man was transferred to our hospital because of a sudden onset of headache and loss of consciousness. The cerebrospinal fluid (CSF) test showed slightly elevated cell counts and protein levels but a negative CSF culture test. Magnetic resonance imaging showed a dumbbell-like cystic lesion with hemorrhagic change at the sella turcica. From the above, the patient was diagnosed with aseptic meningitis caused by pituitary apoplexy. Pituitary hormone replacement therapy was undertaken, and his symptoms fully improved. However, two months later, he complained of a gait disturbance and incontinence that had gradually appeared. Brain imaging with computed tomography showed no ventricular enlargement compared with initial images, although the lateral ventricles were slightly enlarged. As a CSF drainage test improved his symptoms temporarily, sNPH with possible longstanding overt ventriculomegaly in adults (LOVA) background was suspected. We performed a lumboperitoneal shunt (LPS) placement, which improved his symptoms. Conclusion: This case suggests that sNPH can develop even after a small subarachnoid hemorrhage caused by a pituitary apoplexy in LOVA patients. If the aqueduct of Sylvius is open, sNPH with a LOVA background can be successfully treated with LPS placement.

Adult Infratentorial Pial Arteriovenous Fistula Treated with Detachable Coils: A Case Report and a Review of Literature.

An appropriate therapeutic option for pial arteriovenous fistula (PAVF) can vary according to the angioarchtecture of the lesion. We present a case of adult infratentorial PAVF treated by transarterial coil embolization. A 26-year-old man was referred to our institution for an asymptomatic intracranial vascular lesion. Cerebral angiograms revealed PAVF fed by three arteries in the right cerebellomedullary cistern. The feeding arteries were accurately identified by three-dimensional rotational angiography and were successfully embolized using coils while normal arterial flow was preserved. This case report suggests that stepwise transarterial coil embolization can cure PAVF under detailed evaluation of its angioarchitecture.

A Unique Case of Intracranial Amelanotic Melanoma with BRAF V600E Mutation Successfully Treated via Molecular-targeted Therapy.

Melanoma carries a high risk of brain metastasis. A small subset of metastatic melanomas, known as amelanotic melanomas, does not present black coloration, reflecting a lack of melanin pigmentation. Here, we report a case of B-Raf proto-oncogene (BRAF) V600E mutation associated with a metastatic brain tumor caused by the amelanotic melanoma. A 60-year-old man was transferred to our department following acute onsets of left upper limb paralysis and convulsion. In the brain imaging, multiple lesions in the right frontal lobe and left basal ganglia were detected, and the presence of an enlarged left axillary lymph node was revealed. Consequently, we removed the right frontal lesion and performed a biopsy of the left axillary lymph node. Histological analysis of both specimens indicated an amelanotic melanoma, and genetic testing revealed a BRAF V600E mutation. The residual intracranial lesions were treated with stereotactic radiotherapy and molecular-targeted therapy, with dabrafenib and trametinib as the systemic treatment. Based on the Response Evaluation Criteria in Solid Tumors, we determined that the patient achieved complete remission (CR) under uninterrupted molecular-targeted therapy over a period of 10 months. After the temporary withdrawal of dabrafenib and trametinib to avoid hepatic dysfunction, a new intracranial lesion appeared. CR of this lesion was achieved following reinstatement of the two drugs. These results suggest that, under limited conditions, molecular-targeted therapy can produce a sustained response against the intracranial metastasis of melanoma, and the therapy with reduced dose is still effective against a recurrent case after cessation of the therapy due to the toxicity.

Depolarization time and extracellular glutamate levels aggravate ultraearly brain injury after subarachnoid hemorrhage.

Early brain injury after aneurysmal subarachnoid hemorrhage (SAH) worsens the neurological outcome. We hypothesize that a longer duration of depolarization and excessive release of glutamate aggravate neurological outcomes after SAH, and that brain hypothermia can accelerate repolarization and inhibit the excessive release of extracellular glutamate and subsequent neuronal damage. So, we investigated the influence of depolarization time and extracellular glutamate levels on the neurological outcome in the ultra-early phase of SAH using a rat injection model as Experiment 1 and then evaluated the efficacy of brain hypothermia targeting ultra-early brain injury as Experiment 2. Dynamic changes in membrane potentials, intracranial pressure, cerebral perfusion pressure, cerebral blood flow, and extracellular glutamate levels were observed within 30 min after SAH. A prolonged duration of depolarization correlated with peak extracellular glutamate levels, and these two factors worsened the neuronal injury. Under brain hypothermia using pharyngeal cooling after SAH, cerebral perfusion pressure in the hypothermia group recovered earlier than that in the normothermia group. Extracellular glutamate levels in the hypothermia group were significantly lower than those in the normothermia group. The early induction of brain hypothermia could facilitate faster recovery of cerebral perfusion pressure, repolarization, and the inhibition of excessive glutamate release, which would prevent ultra-early brain injury following SAH.

Prognosis Prediction Using Magnetic Resonance Spectroscopy and Oligoclonal Bands in Central Nervous System Methotrexate-associated Lymphoproliferative Disorder.

Central nervous system methotrexate-associated lymphoproliferative disorder (CNS-MTX-LPD) is rare, but its spontaneous regression has been observed in some patients after withdrawal of agents. We herein report three cases of primary CNS-MTX-LPD that received oral MTX for rheumatoid arthritis. Epstein-Barr virus and oligoclonal bands (OCBs) were positive, while proton magnetic resonance spectroscopy (1H-MRS) showed an elevated lipid peak and slightly elevated choline/N-acetylaspartate ratio in common. After MTX withdrawal, brain lesions showed spontaneous regression in all cases. Our patient's 1H-MRS findings and OCBs may reflect a non-monoclonal lymphoproliferative histology as benign-type lesions in CNS-MTX-LPD.

Mobile endovascular therapy for acute treatment of ruptured vertebral artery dissecting aneurysm in multiple hospitals.

BACKGROUND: The patients with ruptured vertebral artery dissecting aneurysm (rVADA) should be treated as early as possible because VADA carries extremely high risk of rebleeding in the acute phase. We have established a mobile endovascular strategy for the patients with rVADA between our flagship center and its affiliated local hospitals. We introduced and reviewed our mobile endovascular therapy in this study. METHODS: We retrospectively evaluated 98 consecutive patients who underwent endovascular surgery for rVADA from 2000 to 2018 at our institution or five affiliated hospitals. When each patient was initially transported to the local affiliated hospitals, neuroendovascular surgeons traveled directly to the affiliated hospital from the flagship center in order to treat the patient there. Clinical outcomes using modified Rankin Scale at 6 months after treatment, radiological results, and procedure-related complications were reviewed to justify our mobile endovascular strategy. RESULTS: All aneurysms were cured successfully by internal trapping. Favorable outcome was achieved in 61 patients (62.2%) even though 53 patients (54.1%) had presented with severe subarachnoid hemorrhage. Overall mortality rate, treatment-related mortality rate, and treatment related complication rate were 18.4% (18/98), 0%, and 16% (16/98), respectively. There were no differences in clinical and radiological outcomes between the patients treated in the flagship center and those who treated in the affiliated hospitals. Treatment in the affiliated hospital was not a predictive factor of unfavorable outcome in our multivariate analysis, and elderly age (≥ 60) was negatively associated with favorable outcome. CONCLUSIONS: Our results prove the efficacy and safety of mobile endovascular therapy for the treatment of rVADA in the ultra-acute stage. Mobile endovascular therapy may work well in the acute treatment of rVADAs in the certain circumstance.

A Child with Paradoxical Cerebral Embolism in Whom Mechanical Thrombectomy Led to a Favorable Outcome.

Objective: We report a case of paradoxical cerebral embolism caused by patent foramen ovale (PFO) that was treated by the direct aspiration first pass technique (ADAPT). Case Presentation: The case involved a 12-year-old boy who had symptoms of dizziness and vomiting the day prior to being admitted to the emergency department. The following morning, consciousness disorder, dysarthria, and right paresis were observed, and he was transferred to our hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) lead to the diagnosis of acute cerebral infarction due to basilar artery (BA) occlusion. Mechanical thrombectomy was performed, and Thrombolysis in Cerebral Infarction (TICI) 3 was obtained. Postoperatively, his consciousness was improved, but echocardiography revealed PFO. Percutaneous PFO closure was performed at our department of pediatric cardiology. Conclusion: For our patient with paradoxical cerebral embolism of the BA caused by PFO more than 6 hours after onset, mechanical thrombectomy with ADAPT using a Penumbra 5MAX ACE68 resulted in a good outcome.

[A Case of Giant Cerebral Aneurysm Treated with Multiple Sheaths Directly Punctured into the Carotid Artery].

When it is difficult to approach the brachial or femoral artery during endovascular surgery, an alternative approach is the direct puncture of the carotid artery. In this case of a giant cerebral aneurysm, we punctured the carotid artery directly and performed flow diverter stent placement and endosaccular coil embolization. Although the procedure required two thick access routes, it was performed after administering two antiplatelet drugs and an anticoagulant in order to achieve reliable hemostasis of the puncture sites after the operation. Direct common carotid artery puncture through a cervical skin incision is useful, because it ensures multiple access routes safely and provides secure hemostasis of the puncture sites.

Cerebellar Blood Flow and Gene Expression in Crossed Cerebellar Diaschisis after Transient Middle Cerebral Artery Occlusion in Rats.

Crossed cerebellar diaschisis (CCD) is a state of hypoperfusion and hypometabolism in the contralesional cerebellar hemisphere caused by a supratentorial lesion, but its pathophysiology is not fully understood. We evaluated chronological changes in cerebellar blood flow (CbBF) and gene expressions in the cerebellum using a rat model of transient middle cerebral artery occlusion (MCAO). CbBF was analyzed at two and seven days after MCAO using single photon emission computed tomography (SPECT). DNA microarray analysis and western blotting of the cerebellar cortex were performed and apoptotic cells in the cerebellar cortex were stained. CbBF in the contralesional hemisphere was significantly decreased and this lateral imbalance recovered over one week. Gene set enrichment analysis revealed that a gene set for "oxidative phosphorylation" was significantly upregulated while fourteen other gene sets including "apoptosis", "hypoxia" and "reactive oxygen species" showed a tendency toward upregulation in the contralesional cerebellum. MCAO upregulated the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the contralesional cerebellar cortex. The number of apoptotic cells increased in the molecular layer of the contralesional cerebellum. Focal cerebral ischemia in our rat MCAO model caused CCD along with enhanced expression of genes related to oxidative stress and apoptosis.

Correction to: High­Mobility Group Box­1­Induced Angiogenesis After Indirect Bypass Surgery in a Chronic Cerebral Hypoperfusion Model.

The original version of this article unfortunately contained a mistake. Figure 5a, b were incorrect. The correct figures are given below.

[A Case of Ruptured Arteriovenous Malformation Successfully Treated with Target Embolization for Pseudoaneurysm Detected Using Chronological Three-dimensional Digital Subtraction Angiography Fusion Images].

We herein report a case of ruptured arterio-venous malformation(AVM)detected using three-dimensional digital subtraction angiography(3DDSA)fusion images and successfully treated with target embolization for pseudoaneurysm. A 50-year-old man with a history of AVM was admitted to our department for the treatment of ruptured high-grade AVM in the right parietal lobe. Although a bleeding point was not evident on DSA, the patient had re-rupture in the right ventricle, one month after admission. Chronological 3DDSA fusion images generated from 3DDSA images taken on admission and after re-rupture revealed a newly visualized intranidal pseudoaneurysm near a hematoma. Contrast-enhanced magnetic resonance imaging showed vessel wall enhancement along the posterior horn of the right ventricle;this enhancement corresponded to the location of the pseudoaneurysm. We planned target embolization for the intranidal pseudoaneurysm to prevent re-bleeding. The origin of the feeder was so steep that a microcatheter could not be advanced deeply, and embolization with 20% n-butyl-2-cyanoacrylate resulted in proximal occlusion. Follow-up angiography 1 week after embolization showed complete disappearance of the pseudoaneurysm, and the patient had no recurrence of aneurysm until one year.

Safety and efficacy of staged angioplasty for patients at risk of hyperperfusion syndrome: a single-center retrospective study.

PURPOSE: Intracranial hemorrhage following hyperperfusion syndrome (HPS) is a rare but potentially fatal complication after carotid artery stenting (CAS). Staged angioplasty (SAP) is a two-stage form of CAS that can prevent the abrupt increase of cerebral blood flow. In this study, we investigated the safety and efficacy of SAP. METHODS: One hundred thirty-four patients who underwent CAS for high-grade carotid artery stenosis between January 2010 and December 2018 were enrolled. Patients who showed severe impairment of hemodynamic reserve in 123I-IMP SPECT with acetazolamide received SAP (SAP group), while the others received regular CAS (RS group). RESULTS: Twenty-six (19.4%) patients at risk for HPS received SAP. HPS was not observed in either group. Diffusion-weighted image (DWI)-positive lesions on postoperative MRI were observed in 56 (52.3%) cases in the RS group and 16 (64.0%) cases in the SAP group. Symptomatic procedure-related complications occurred in 5 (4.6%) cases in the RS group and 1 (3.8%) case in the SAP group. These differences were not statistically significant. Modified Rankin Scale score had declined 30 days after discharge in 4 (3.0%) cases. Distal filter protection was significantly correlated to the occurrence of new DWI-positive lesions. CONCLUSIONS: For patients at high risk of HPS, SAP was a reasonable treatment strategy to prevent HPS. SAP did not increase the rate of DWI-positive lesions or procedure-related complications compared with regular CAS.

Cell encapsulation enhances antidepressant effect of the mesenchymal stem cells and counteracts depressive-like behavior of treatment-resistant depressed rats.

Despite the advances in pharmacological therapies, only the half of depressed patients respond to currently available treatment. Thus, the need for further investigation and development of effective therapies, especially those designed for treatment-resistant depression, has been sorely needed. Although antidepressant effects of mesenchymal stem cells (MSCs) have been reported, the potential benefit of this cell therapy on treatment-resistant depression is unknown. Cell encapsulation may enhance the survival rate of grafted cells, but the therapeutic effects and mechanisms mediating encapsulation of MSCs remain unexplored. Here, we showed that encapsulation enhanced the antidepressant effects of MSCs by attenuating depressive-like behavior of Wistar Kyoto (WKY) rats, which are considered as a promising animal model of treatment-resistant depression. The implantation of encapsulated MSCs (eMSCs) into the lateral ventricle counteracted depressive-like behavior and enhanced the endogenous neurogenesis in the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus, whereas the implantation of MSCs without encapsulation or the implantation of eMSCs into the striatum did not show such ameliorative effects. eMSCs displayed robust and stable secretion of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, fibroblast growth factor-2, and ciliary neurotrophic factor (CNTF), and the implantation of eMSCs into the lateral ventricle activated relevant pathways associated with these growth factors. Additionally, eMSCs upregulated intrinsic expression of VEGF and CNTF and their receptors. This study suggests that the implantation of eMSCs into the lateral ventricle exerted antidepressant effects likely acting via neurogenic pathways, supporting their utility for depression treatment.

Metal artifact reduction algorithm for image quality improvement of cone-beam CT images of medium or large cerebral aneurysms treated with stent-assisted coil embolization.

PURPOSE: The aim of the present study was to assess image quality improvement using a metal artifact reduction (MAR) algorithm in cases of medium or large cerebral aneurysms treated with stent-assisted coil embolization (SAC), and to analyze factors associated with the usefulness of the MAR algorithm. METHODS: We retrospectively evaluated the cone-beam computed tomography (CBCT) data sets of 18 patients with cerebral aneurysms treated with SAC. For subjective analysis, images of all cases with and without MAR processing were evaluated by five neurosurgeons based on four criteria using a five-point scale. For objective analysis, the CT values of all cases with and without MAR processing were calculated. In addition, we assessed factors associated with the usefulness of the MAR by analyzing the nine cases in which the median score for criterion 1 improved by more than two points. RESULTS: MAR processing improved the median scores for all four criteria in 17/18 cases (94.4%). Mean CT values of the region of interest at the site influenced by metal artifacts were significantly reduced after MAR processing. The maximum diameter of the coil mass (< 17 mm; odds ratio [OR], 4.0; 95% confidence interval [CI], 1.2-13.9; p = 0.02) and vessel length covered by metal artifacts (< 24 mm; OR, 2.3; 95% CI, 1.1-4.7; p = 0.03) was significantly associated with the usefulness of the MAR. CONCLUSIONS: This study suggests the feasibility of a MAR algorithm to improve the image quality of CBCT images in patients who have undergone SAC for medium or large aneurysms.

Results of 1940 embolizations for dural arteriovenous fistulas: Japanese Registry of Neuroendovascular Therapy (JR-NET3).

OBJECTIVE: Embolization is the most common treatment for dural arteriovenous fistulas (dAVFs). A retrospective, multicenter observational study was conducted in Japan to clarify the nature, frequency, and risk factors for complications of dAVF embolization. METHODS: Patient data were derived from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). A total of 40,169 procedures were registered in JR-NET3, including 2121 procedures (5.28%) in which dAVFs were treated with embolization. After data extraction, the authors analyzed complication details and risk factors in 1940 procedures performed in 1458 patients with cranial dAVFs treated with successful or attempted embolization. RESULTS: Transarterial embolization (TAE) alone was performed in 858 cases (44%), and transvenous embolization (TVE) alone was performed in 910 cases (47%). Both TAE and TVE were performed in one session in 172 cases (9%). Complications occurred in 149 cases (7.7%). Thirty-day morbidity and mortality occurred in 55 cases (2.8%) and 16 cases (0.8%), respectively. Non-sinus-type locations, radical embolization as the strategy, procedure done at a hospital that performed dAVF embolization in fewer than 10 cases during the study period, and emergency procedures were independent risk factors for overall complications. CONCLUSIONS: Complication rates of dAVF embolization in Japan were acceptable. For better results, the risk factors identified in this study should be considered in treatment decisions.

A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3.

BACKGROUND: The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3. METHODS: A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3. RESULTS: The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001). CONCLUSIONS: Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization.

High-Mobility Group Box-1-Induced Angiogenesis After Indirect Bypass Surgery in a Chronic Cerebral Hypoperfusion Model.

High-mobility group box-1 (HMGB1) is a nuclear protein that promotes inflammation during the acute phase post-stroke, and enhances angiogenesis during the delayed phase. Here, we evaluated whether indirect revascularization surgery with HMGB1 accelerates brain angiogenesis in a chronic cerebral hypoperfusion model. Seven days after hypoperfusion induction, encephalo-myo-synangiosis (EMS) was performed with or without HMGB1 treatment into the temporal muscle. We detected significant increments in cortical vasculature (p < 0.01), vascular endothelial growth factor (VEGF) expression in the temporal muscle (p < 0.05), and ratio of radiation intensity on the operated side compared with the non-operated side after EMS in the HMGB1-treated group than in the control group (p < 0.01). Altogether, HMGB1 with EMS in a chronic hypoperfusion model promoted brain angiogenesis in a VEGF-dependent manner, resulting in cerebral blood flow improvement. This treatment may be an effective therapy for patients with moyamoya disease.

Lithium counteracts depressive behavior and augments the treatment effect of selective serotonin reuptake inhibitor in treatment-resistant depressed rats.

Wistar Kyoto (WKY) rats are a useful animal model of treatment-resistant depression. Lithium is effective for treating recurrent mood disorders or treatment-resistant depression, and lithium augmentation treatment is also useful for treatment-resistant depression. However, the treatment effect of lithium on the depressive behavior of WKY rats remains poorly understood, and whether lithium augments the treatment effect of antidepressants in WKY rats is also unknown. In this study, we evaluated the treatment effect of lithium in WKY rats. We also sought to determine if lithium treatment augments the treatment effect of fluoxetine. Lithium was administered for 15 consecutive days and fluoxetine was administered 23.5, 5, and 1 h before the forced swim test (FST) day 2, based on previous studies. Lithium treatment counteracted depressive behavior in the FST and increased hippocampal neurogenesis. Additionally, co-administration of lithium and fluoxetine augmented the treatment effect observed in the FST and in hippocampal neurogenesis in WKY rats, although fluoxetine monotherapy showed no treatment effect. Lithium prevented an increase in body weight, similar to its effect in human patients. These results are consistent with those of lithium augmentation treatment for human patients with treatment-resistant depression. They suggest that WKY rats are a promising animal model for treatment-resistant depression. However, lithium treatment has various side effects. A new treatment with the same anti-depressive effect as fluoxetine + lithium treatment and fewer side effects compared with lithium would be desirable for patients with treatment-resistant depression.

Treatment Outcome of Intracranial Tumor Embolization in Japan: Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3).

Embolization for intracranial tumor is performed as a standard endovascular treatment. A retrospective, multicenter, observational study was conducted to clarify the nature, frequency, and risk factors of complications in intracranial tumor embolization. Patients were derived from the Japanese Registry of NeuroEndovascular Therapy (JR-NET3) using data taken from January 2010 through December 2014 in Japan. A total of 40,169 patients were enrolled in JR-NET3, of which, 1,545 patients (3.85%) with intracranial tumors underwent embolization. The primary end point was the proportion of patients with a modified Rankin scale (mRS) score of 0-2 (independency) at 30 days after embolization. The secondary end point was the occurrence of complications related to the procedures. The risk factors of the development of complications were analyzed. The proportion of patients with mRS scores ≤2 at 30 days after procedure was 89.5%. Complications occurred in 57 of the 1544 patients (3.7%). Multivariate analysis showed that target vessels other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; P <0.001) and use of liquid material (OR, 2.65; 95% CI, 1.50-4.68; P <0.001) were significantly associated with the development of complications. In JR-NET3, the primary end point was 89.5%, and the procedure-related complication rate was 3.7%. Embolization from other than ECA was significant risk factor of the complications. In addition, increasing usage of liquid embolic material worsened the risk of complications.

Endovascular treatment for unruptured aneurysm associated with persistent primitive trigeminal artery: a case report and literature review.

The persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis, and the incidence of cerebral aneurysms associated with the PPTA is approximately 4%. Since PPTA aneurysms often have a wide neck and other vascular anomalies, endovascular treatment using an adjunctive technique is the current first-line therapy. Here, we report a case of PPTA aneurysm treated by coil embolization with a stent-assisted technique. A detailed evaluation of the size and course of all vessels and collateral flow, including the Allcock test and balloon test occlusion, is necessary when deciding on the treatment strategy.