Transient atrial mechanical dysfunction assessed in acute phase of embolic stroke of undetermined source.

BACKGROUND AND PURPOSE: Paroxysmal atrial fibrillation (PAF) has been suggested as a major cause of embolic stroke of undetermined source (ESUS). Transient atrial mechanical dysfunction (stunning) frequently occurs after conversion of atrial fibrillation to sinus rhythm. The study aim was to determine if reversible atrial mechanical dysfunction in ESUS could help elucidate the mechanism of stroke. METHODS: Eighty-five consecutive patients with acute ischemic stroke were enrolled according to the following inclusion criteria: [1] ≥55 years old; [2] normal sinus rhythm upon admission; [3] no apparent embolic source; and [4] transthoracic echocardiographic evaluation had been performed in both the early phase (<72 h) and late phase (>7 days) after stroke onset. There were 27 patients in the lacunar or atherothrombotic infarction group (controls), 22 in the PAF group, and 36 in the ESUS group. To determine atrial stunning, transmitral flow velocity profiles (Doppler peak E- [early diastolic] and A- [atrial systolic] waves) were obtained. RESULTS: In the early phase, an E/A velocity ratio ≥ 1.0 was less common in the control group (1 patient, 3.7%) than in the PAF group (19 patients, 86.4%; p < 0.001) and ESUS group (10 patients, 27.8%; p < 0.05). In the late phase, the E/A ratio decreased to less than 1.0 in six patients (31.6%) who had PAF and in eight patients (80.0%) who had ESUS. CONCLUSION: Transient atrial mechanical dysfunction could be a helpful finding for elucidating the stroke mechanism in patients with ESUS, and early echocardiographic assessment could improve its detection.

Mechanical evaluation of cerebral aneurysm clip scissoring phenomenon: comparison of titanium alloy and cobalt alloy.

Cerebral aneurysm clip blades crossing during surgery is well known as scissoring. Scissoring might cause rupture of the aneurysm due to laceration of its neck. Although aneurysm clip scissoring is well known, there have been few reports describing the details of this phenomenon. Quasi-scissoring phenomenon was introduced mechanically by rotating the clip head attached to a silicone sheet. The anti-scissoring torque during the twist of the blades was measured by changing the depth and the opening width. The closing force was also evaluated. Sugita straight clips of titanium alloy and cobalt alloy were used in the present study. In both materials, the anti-scissoring torque and the closing force were bigger 3 mm in thickness than 1 mm. The initial closing forces and the anti-scissoring torque values at each rotation angles were increased in proportion to depth. Closing forces of titanium alloy clip were slightly higher than those of cobalt alloy clip. By contrast, anti-scissoring torque values of cobalt alloy clip were bigger than those of titanium alloy clip in all conditions. In condition of 3 mm in thickness and 3 mm in depth, anti-scissoring torque vales of titanium alloy clip decreased suddenly when an angle surpassed 70 degrees. Aneurysm clip scissoring phenomenon tends to occur when clipping the aneurysm neck only with blade tips. Based on the results of this experiment, titanium alloy clip is more prone to scissoring than cobalt alloy clip under the condition that the wide blade separation distance and the shallow blade length.

Accurate Detection of Tumor Infiltration by 11C-Methionine Positron Emission Tomography in a Patient with Central Nervous System Intravascular Lymphoma: A Case Report.

Intravascular lymphoma (IVL) is a rare and clinically devastating subtype of extranodal diffuse large B-cell lymphoma with a distinct presentation. Diagnostic difficulty derives from marked variability in clinical presentations and nonspecific laboratory and radiological findings, especially when central nervous system (CNS) symptoms are the only manifestation. Establishing the diagnosis premortem thus remains a major challenge. We describe a 70-year-old male with CNS IVL. He presented with acute onset of neurocognitive impairments. Diffusion-weighted magnetic resonance imaging (MRI) showed multiple high-intensity areas suggesting occlusive cerebrovascular disease due to emboli, but extensive investigations detected no embolic sources. Intracranial neoplasm was included in a differential diagnosis based on elevated serum lactate dehydrogenase and interleukin 2 receptor levels. Gadolinium-enhanced MRI or 18-fluorodeoxyglucose positron emission tomography (PET) failed to demonstrate specific findings leading to a definite diagnosis, while 11C-methionine PET (MET-PET) distinctively demonstrated an area of focally increased MET uptake in the frontal cortex, suggesting the extent of tumor infiltration. Stereotactic biopsy was conducted under MET-PET imaging guidance and immunohistological examinations confirmed the proliferation and aggregation of CD20-positive lymphoma cells within the lumina of small blood vessels. The findings of the present case first suggest that MET-PET may provide important information on the diagnosis of CNS IVL and on the selection of the optimal site for brain biopsy. Further investigation is necessary to clarify whether positive findings on MET-PET are truly specific and pathognomonic for CNS IVL.

[Clinical analysis of treatment and long-term outcome in 56 craniopharyngiomas].

In order to improve QOL in patients with craniopharyngioma, retrospective analysis was performed to discover factors for influencing functional outcome and the best treatment strategy. 56 patients were treated between 1978 and 2005. They were initially treated with surgery and surgical cure was obtained in 29 patients (Group A). Subtotal tumor resection with prophylactic radiation was performed in 8 patients (Group D). Tumor recurrence was noted in 19 patients and stereotactic radiation or 2nd operation was performed in 11 patients (Group B). 2nd operation and fractionated radiation were undertaken in 8 patients (Group C). Endocrine, vision and recognition were scored from 2 to 0, respectively; 2 indicates normal, 1 partially disturbed, 0 fully disturbed. The mean score before treatment was 4.7 and the final score was 3.9. Factors leading to poor outcome included extrasellar origin, solid tumor, bad score before treatment, 2nd surgery for recurrence. The change of scores after the treatment was -0.1 in group A, -0.7 in Group B, -0.9 in Group C and 0.3 in Group D. Maximum tumor removal should be attempted with functional preservation. Subtotal removal with prophylactic radiation is recommended if the patient has normal hypothalamic function.

Clinical characteristics of ruptured distal middle cerebral artery aneurysms: Review of the literature.

Middle cerebral artery (MCA) aneurysms usually arise at the primary MCA bifurcation or trifurcation. Distal MCA aneurysms are rarely considered as sources of aneurysmal subarachnoid hemorrhage (SAH). It has been reported that ruptured distal MCA aneurysms are associated with head trauma, neoplastic emboli, arterial dissection, or bacterial infection. We experienced five cases of ruptured distal MCA aneurysms and evaluated their clinical characteristics. Retrospective analysis of aneurysmal SAH at Kobayashi Neurosurgical Neurological Hospital was performed from January, 2004 to December, 2014. Clinical characteristics of ruptured distal MCA aneurysms were analyzed using our database. Among 191 aneurysmal SAH patients, there were five ruptured distal MCA aneurysms. All patients did not have any specific medical problems such as infectious disease, head trauma, or cardiac disorders. The incidence of ruptured distal MCA aneurysm was higher than expected and was equivalent to 9.4% of the total ruptured MCA aneurysms. Strong male predominance (80%) and M2-3 junction aneurysm preponderance (80%) were observed. In addition, there were only two patients (40%) with intracerebral hematoma in our study. We reported five cases of ruptured distal MCA aneurysms. Although ruptured distal MCA aneurysms are thought to be rare as sources of aneurysmal SAH, the incidence of ruptured distal MCA aneurysm was 9.4% of all ruptured MCA aneurysms in our study. Ruptured distal MCA aneurysms should be considered as sources of aneurysmal SAH without intracerebral hematoma.

Open Embolectomy of Large Vessel Occlusion in the Endovascular Era: Results of a 12-Year Single-Center Experience.

BACKGROUND: Mechanical endovascular embolectomy using stent retrievers has gained popularity for treatment of large vessel occlusion in acute ischemic stroke. Use of open embolectomy as a direct surgical treatment has been limited, likely owing to the technical difficulty, therapeutic time window, and time-consuming procedure. METHODS: We retrospectively reviewed clinical and radiographic records of patients who underwent open embolectomy for major artery occlusion at an acute stage. Clinical features, complications, and outcome of patients were analyzed. RESULTS: From January 2004 to September 2016, 153 patients underwent 157 open embolectomies for major artery occlusion. Complete recanalization was achieved in 96.2% of patients. A favorable outcome was observed in 43.9%. Cerebral aneurysm along the occluded artery was observed in 11 patients with 12 aneurysms. CONCLUSIONS: Open embolectomy resulted in a high complete recanalization rate with an acceptable safety profile. Open embolectomy is a safe and durable method of cerebral recanalization in patients with embolic stroke and can be considered as a potential treatment if endovascular embolectomy cannot be performed. The details of the occluded arteries presented here will be useful for endovascular surgeons to prevent complications.

Role of superior hypophyseal artery in visual function impairment after paraclinoid carotid artery aneurysm surgery.

OBJECT: Although a number of studies have assessed the surgical treatment of paraclinoid-segment carotid artery aneurysms and resulting visual complications, less attention has been given to the results with respect to the superior hypophyseal artery (SHA). The authors evaluated the relationship between the aneurysm, the SHA itself, and postoperative visual function in patients with ruptured and unruptured SHA aneurysms. METHODS: From January 1991 through December 2013, 181 patients with 190 paraclinoid carotid artery aneurysms received treatment at Shinshu University Hospital and its affiliated hospitals. The authors retrospectively analyzed charts, operative records, operative videos, and neuroimaging findings for these patients with or without postoperative visual complications. RESULTS: The authors identified 72 SHA aneurysms in 70 patients (mean age 58 years). Of 69 patients (1 patient died) evaluated, postoperative visual complications occurred in 9 (13.0%). Although the aneurysm size and SHA sacrifice did not lead to postoperative visual impairment, simultaneous treatment of bilateral aneurysms was a risk factor for postoperative visual complications. CONCLUSIONS: Unilateral SHA impairment may be safe (i.e., it may not induce ischemia of the optic pathway) for many, but not all, patients with SHA aneurysm.

Rescue revision techniques for end-to-side anastomosis: Technical note.

BACKGROUND: Extracranial-intracranial bypass operation is an essential procedure for cerebrovascular surgeons. Proper procedure of the bypass requires special skills, selected instruments, and training in the microsurgical laboratory. In spite of the high success rate for extracranial-intracranial bypass, a potential pitfall while performing an end-to-side anastomosis is poor blood flow or occlusion at the anastomotic site during surgery. If this happens, revision procedure is necessary. METHODS: We introduce our salvage techniques for anastomosis revision with or without recipient artery occlusion. RESULTS: With this method, ischemic complication related to revision procedure minimizes ischemic complications. CONCLUSIONS: The present technique is a simple method for anastomosis revision.

Results of clipping surgery for aneurysmal subarachnoid hemorrhage in the ninth and tenth decades of life.

This study investigated the outcome of clipping surgery for ruptured aneurysms in patients older than 80 years of age. From 1988 to 2011 data were retrospectively reviewed, and 196 patients treated with clipping obliteration for aneurysmal subarachnoid hemorrhage were identified. Patients were divided into two age groups of 80-84 and ⩾ 85 years old. The Glasgow Outcome Scale score was assessed at discharge and classified as favorable (good recovery or moderate recovery) or unfavorable (severe disability, vegetative state, or dead). Radiological and clinical characteristics were compared between the two groups. A favorable outcome was achieved in 106 (54.1%) of the 196 patients. Preoperative grade and Fisher grade were significantly associated with unfavorable outcome, but age was not. Based on logistic regression analysis, poor preoperative grade and ruptured anterior cerebral artery aneurysm were the predictors of unfavorable outcome, but advanced age (⩾ 85 years old) was not. Advanced age itself did not affect the outcome of the elderly patients who underwent clipping surgery for aneurysmal subarachnoid hemorrhage.

Isolated primary malignant lymphoma arising from the optic chiasm.

Isolated primary malignant lymphoma rarely arises from the anterior visual pathway. A 59-year-old previously healthy man presented with progressive, painless, bilateral visual disturbance. Neurological imaging revealed an enhancing mass arising from the optic chiasm. Open biopsy was carried out under monitoring of visual evoked potentials and a histopathological diagnosis of diffuse large B-cell lymphoma was made. As systemic examination did not show any evidence of systemic lymphoma, we concluded that this patient had an isolated primary malignant lymphoma at the anterior visual pathway.

Spontaneous regression of multicentric pilocytic astrocytoma with CSF dissemination in an adult.

We present a case of spontaneous regression of multicentric pilocytic astrocytoma with cerebrospinal fluid (CSF) dissemination without neurofibromatosis type 1 (NF1) in an adult, the first such case reported. Magnetic resonance imaging (MRI) showed multiple low signal intensity lesions on T1-weighted images and high signal intensity areas on T2-weighted images in the bilateral thalamus, basal ganglia and midbrain. Contrast-enhanced MRI revealed that small, enhanced lesions were seen in the basal ganglia and the pineal region. Neuroendoscopic biopsy and third ventriculostomy were performed. Intraoperative findings demonstrated CSF dissemination. Histologically, the specimens showed pilocytic astrocytoma. Serial MRIs showed regression of the tumor without any additional treatment. The clinical features of spontaneous regression of pilocytic astrocytoma are discussed.