Endovascular Treatment of Cerebral Venous Circulation Dysfunction Caused by Hemodialysis Shunt: A Case Report.

Objective: Central venous disease, defined as ≥50% stenosis or obstruction of central veins, is one of many life-threatening complications faced by patients on hemodialysis. It often presents as upper limb edema to the arteriovenous (AV) shunt for hemodialysis, although neurological symptoms are rare. We report a case of central venous disease with neurological symptoms associated with endovascular therapy. Case Presentation: A 79-year-old man presented with status epilepticus. His past medical history included rectal carcinoma when he was 69 years old and indication for hemodialysis when he was 79 years old. However, he had no history of neurological disease or epilepsy. On arrival at our facility, CT perfusion revealed venous circulation dysfunction on the left cerebral hemisphere. DSA demonstrated regurgitation from the AV shunt on left upper limb to the cerebral veins and obstruction of the left subclavian vein. Ligation of the causal AV shunt was deemed difficult due to surrounding edema; therefore, endovascular transarterial coil embolization was performed. After completely occluding the AV shunt, patient's condition improved significantly. The patient was discharged 3 days later without neurologic symptoms, with no recurrence of epilepsy was observed to date. Conclusion: Coil embolization of causal AV shunt significantly improved the neurological symptoms of central venous disease.

Mechanical Thrombectomy for Acute Ischemic Stroke Caused by Prosthetic Aortic Valve Endocarditis Due to Exophiala dermatitidis Infection: A Case Report.

Prosthetic valve endocarditis (PVE) can cause large cerebral vessel occlusion. Many reports suggested that mechanical thrombectomy (MT) is effective and useful for early diagnosis from the histopathological findings of thrombus. We present the case of a 62-year-old man, with a history of prosthetic aortic valve replacement and pulmonary vein isolation for his atrial fibrillation, who developed a high fever and an acute neurological deficit, with left hemiplegia and speech disorder. He was diagnosed as having an acute right middle cerebral artery embolism and underwent an MT. The embolic source was found to be a PVE vegetation. However, histopathological analysis of the thrombus could not detect the actual diagnosis. Although he was treated for bacterial endocarditis, his blood culture revealed a rare fungal infection with Exophiala dermatitidis not until >3 weeks after admission. Subsequently, a ß-D-glucan assay also indicated elevated levels. Although he underwent an aortic valve replacement on day 36, MRI showed multiple minor embolic strokes till that day. Early diagnosis of fungal endocarditis and detection of the causative pathogen are still challenging, and the disease has a high risk of occurrence of early and repeated embolic stroke. In addition to clinical findings and pathological studies, ß-D-glucan assay might be a good tool for the diagnosis and evaluation of fungal endocarditis.

[Paroxysmal Atrial Fibrillation after Percutaneous Thrombectomy on Day 5 of Onset of Cerebral Embolism:A Case Report].

INTRODUCTION: We report a case of embolic stroke with an atypical course after endovascular therapy performed during the subacute stage of progressive stroke, where symptom relapse could not be controlled despite medical treatment. CASE PRESENTATION: An 81-year-old woman developed slight weakness in her left leg and was hospitalized three days after the onset of symptoms. On admission, her consciousness was almost clear and she exhibited left hemiparesis. The computed tomography(CT)and magnetic resonance imaging(MRI)revealed a cerebral infarction in the right caudate head and corona radiata, and CT perfusion showed no difference in the cerebral blood flow. However, three-dimensional computed tomography angiography showed right M1 occlusion. Considering the clinical course of the leg weakness without atrial fibrillation, antiplatelet therapy for atherosclerotic cerebral infarction was administered. Five days after the symptom onset, the left hemiparesis deteriorated. CT and diffusion-weighted MRI showed increasing edema associated with the cerebral infarction, and CTP showed decreased cerebral blood flow in the right middle cerebral artery region. Because angiography revealed an obstruction involving a long lesion with loss of contrast, we suspected an embolic stroke. Endovascular surgery was performed successfully using the Penumbra system. Postoperatively, the hemiparesis resolved and the patient was transferred to the rehabilitation hospital. CONCLUSION: In rare cases, patients with an embolic stroke develop gradual progression of symptoms. To differentiate between cardioembolic stroke and atherosclerotic cerebral infarction in such patients, a follow-up examination of the brain blood flow must be performed, especially when there is a change in symptoms. This may provide useful information for intravascular treatment even in the subacute period.

[Neuro-Endoscopic Surgery for Multi-Lobular Chronic Subdural Hematoma].

BACKGROUND: Chronic subdural hematoma(CSDH)generally occurs in the elderly, and is usually treated by burr-hole craniotomy with closed-system drainage. Treatment of recurrent CSDH is more challenging, especially when the hematoma is multi-lobular. A variety of approaches to the management of multi-lobular CSDH have been described, including evacuation through a wide craniotomy, placement of an Ommaya reservoir, subdural peritoneal shunting, and embolization of the middle meningeal artery. We have previously reported a method of evacuating multi-lobular CSDH through a small craniotomy using a rigid endoscope and aspiration tube. The objective of this study was to compare our operative method with others from the literature. MATERIALS AND METHODS: Between January 2012 and October 2016, eight patients diagnosed with multi-lobular CSDH using computed tomography(CT)imaging underwent endoscopic evacuation. First, we established a 3×3cm craniotomy at a position where a rigid endoscope and aspiration tube would be able to reach as much of the hematoma cavity as possible in the longitudinal plane. Second, after identifying and removing the outer membrane of the CSDH with the scope, we evacuated the hematoma longitudinally, keeping the inner membrane intact. We also applied monopolar diathermy to any obvious bleeding points and the capillary network on the outer membrane of the CSDH, using the aspiration tube. RESULT: The mean duration of surgery was 42 minutes. Follow-up CT scan revealed no recurrence in any of the cases, and neurologic function improved in all patients postoperatively. CONCLUSION: A multi-lobular CSDH can be drained quickly and effectively using a rigid endoscope and aspiration tube through a small craniotomy. In a cohort of eight patients, postoperative neurologic recovery was observed in all cases with no evidence of recurrence. This technique could be used in any facility with ready access to CT imaging and a rigid endoscope.

[Development of a New Neuro-Endoscope Cylinder for Safer Neuro-Endoscopic Surgery].

Objective:Successful endoscopic surgery for intracerebral hemorrhage has previously been hampered by impaired visualization during the operation to remove the clot, leading to a relatively low removal efficiency for hematomas. However, in multiple case series, intracerebral hematomas have been reported to be removed using endoscopic visualization. Although using tubular retractors in cranial surgery is one technique to gain access to deep-seated lesions, it is difficult to confirm the depth of the retractor's sheath in the surgical field using only the outer sheath. We built various-sized cylinders, developed by the Japan Science and Technology Agency's(JST)program for revitalization promotion, with scales that are visible during both endoscopic and radiographic procedures. We report the use of these cylinders in clinical cases. Method and Results:The JST-developed cylinders benefit from new techniques for plating and tantalum film implantation used to form tubes made of fluorinated ethylene propylene. We successfully removed various hematomas using these cylinders, as we were able to clearly visualize the border of the brain parenchyma and the depth of the hematoma using the cylinder. Conclusion:Cylinders with visible scales for both endoscopic and radiographic uses developed by the JST programs may provide greater patient safety during endoscopic surgery. We next plan to improve the hardness, length, and smoothness of the groove on the cylinder.

Histologic study of arteriovenous shunts in the normal dura mater adjacent to the transverse sinus.

BACKGROUND: Although AV shunts are known to exist in the normal dura mater, their histologic appearance has not been examined in detail. Arteriovenous shunts in the normal dura mater adjacent to the transverse sinus, the most frequent site of DAVFs, were studied histologically. METHODS: Normal dura mater adjacent to the transverse sinus was obtained from 8 cadavers. Each specimen was cut into approximately 4-microm-thick serial sections; these were stained by the elastic Masson method and examined under a light microscope. RESULTS: Of the 8 specimens, 5 harbored a total of 6 AV shunts; no shunts were found in the other 3 specimens. The shunts, located in the supratentorial (n = 1) and infratentorial dura mater (n = 4) and in the tentorium cerebelli (n = 1), were classified into 2 types. In direct-type shunts, the artery connected directly to the vein; the diameter of these shunts ranged from 40 to 80 microm. In indirect-type shunts, the artery and vein were parallel and were indirectly connected by a shunt vessel, producing an H shape. The diameter of these shunt vessels ranged from 30 to 45 microm. All 6 shunts were connected to veins or the venous lake; none connected directly to the transverse sinus. CONCLUSIONS: The existence of direct- and indirect-type AV shunts in the normal dura mater was confirmed histologically. Both types exhibited the histologic features of DAVFs, suggesting that AV shunts in the normal dura mater might be involved in the etiology of DAVFs.

Perinidal dilated capillary networks in cerebral arteriovenous malformations.

OBJECTIVE: The perinidal vascular structures of cerebral arteriovenous malformations were examined, to clarify their pathomorphological features. METHODS: Twenty-two resected specimens of human brain structures adjacent to the nidus were examined. The vessels surrounding the nidus were three-dimensionally reconstructed with a computer graphics system. RESULTS: In all cases, the analysis of serial sections revealed that perinidal dilated capillaries were located in brain tissue 1 to 7 mm from the nidal border. The vessels surrounding the nidus demonstrated markedly dilated capillary networks (perinidal dilated capillary network [PDCN]). The diameters of the vessels forming the PDCN were 10 to 25 times those of normal capillaries. The PDCN connected not only to the nidus, feeding arteries, and draining veins, via arterioles and venules, but also to the normal capillary network, arterioles, and venules. CONCLUSION: Without exception, each nidus was accompanied by a PDCN, which connected not only to the nidus, feeding arteries, and draining veins, via arterioles and venules, but also to normal capillaries, arterioles, and venules. The PDCN should be considered in studies aimed at gaining an understanding of the mechanisms underlying the intraoperative and postoperative bleeding, growth, and recurrence of surgically treated cerebral arteriovenous malformations.

[Dramatic but temporary improvements in a case of CNS intravascular malignant lymphomatosis].

A 54-year-old man with a past history of gastric malignant lymphoma treated by the total gastrectomy and the chemotherapy, developed bilateral sudden deafness one year later. Two years after the gastrectomy he became abruptly paraplegic with sensory impairments of the lower extremities and neurogenic bladder. Serum LDH and soluble IL-2 receptor were high in titers (552 U/l and 1,090 U/l, normal range 145-519). Although the imaging studies of the spinal cord were negative, the myelopathic symptoms resolved dramatically after a course of pulse dose methylprednisolone therapy. However, he soon developed an abnormal behavior and mental deterioration in 3 weeks. The MRIs of the brain revealed abnormal signals compatible with multiple cerebral infarctions. As intravascular malignant lymphomatosis (IML) was suspected because of the laboratory and MRI findings, biopsies of the skin, the bone marrow, the muscle and the lymph node were carried out, without evidence of lymphoma. The brain biopsy ultimately confirmed the presence of IML. The patient remarkably responded to biweekly CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) therapy in terms of regaining the mental alertness and improved hearing. However, the CHOP therapy was prematurely interrupted prior to completion because of infective arthritis. The relapse soon ensued, and he died 6 months after admission. This case was of interest because a solid gastric lymphoma appears to have transformed into the form of intravascular lymphomatosis without mass formations or leukemic changes. Although the neurological symptoms in association with IML are thought to be the results of ischemic events, this case illustrates a remarkable reversibility of the symptoms. This implies that the cerebral symptoms are not necessarily the results of typical ischemic infarction, but due to relative ischemia because of chiefly capillary-venous occlusion by lymphoma cells. The majority of the symptoms is thus attributable to the functional impairment. Therefore, the therapeutic intervention may dramatically improve the symptoms due to IML.