Chordae Willisii of the dural sinuses: an anatomical study using magnetic resonance imaging.

PURPOSE: The chordae Willisii (CWs), trabecular projections into the lumen of the dural sinuses, are not well understood. We aimed to explore them using magnetic resonance imaging (MRI). METHODS: Eighty-five patients underwent volumetric contrast-enhanced MRI, while another 30 underwent a fluid-attenuated inversion recovery (FLAIR) sequence in the coronal section. RESULTS: The CWs were detected as linear filling defects lying in the dural sinuses, adjacent to the surrounding dura mater. They were found in the superior sagittal sinus (SSS) in 68.2% of the patients, most frequently in the middle third, with laminar appearance. In 27.1% of the patients, the CWs divided the SSS lumen into separate channels. The CWs were identified in the transverse sinus, transverse-sigmoid sinus junctional area and sigmoid sinus, and straight sinus in 54.1, 47.1, and 8.2%, respectively. On the FLAIR images, dural septi partially dividing the SSS lumen were identified in all patients. In addition, in 73.3% of the patients, fine linear structures were observed in the lumen with inconstant arrangements. CONCLUSIONS: The CWs may be constant structures distributed over the lumen of the intracranial dural sinuses. Contrast-enhanced MRI may be useful for detecting laminar CWs. The FLAIR sequence may be advantageous for delineating the dural septi projecting into the lumen of the dural sinuses.

Unusually elongated superior thyroid cornu associated with recurrent cerebral embolisms.

The superior thyroid cornu (STC) is a normal anatomic structure that forms part of the thyroid cartilage. Here, we report a patient with unusually elongated and ossified STC that might result in recurrent cerebral embolisms. During a second endovascular therapy for recurrent middle cerebral artery embolism, a segment with an irregular filling defect was noted in the internal carotid artery (ICA), at the C1 level. This defect was unnoticed during the initial endovascular procedure. Three-dimensional computed tomography angiography performed after the second endovascular procedure revealed an ICA segment located between the STC and C1 with a tortuous course and irregular wall of the ICA. Therefore, we assumed that STC compression of the ICA could have resulted in thrombus formation at the site and consequent cerebral embolism. The STC should be considered a structure responsible for cerebral embolism. Careful evaluation of the entire ICA course is imperative prior to performing an endovascular thrombectomy for acute embolic occlusion of the middle cerebral artery.

Diameters of the optic sheath and superior ophthalmic vein can expand and contract at positional changes: a magnetic resonance imaging study.

PURPOSE: This study aimed to explore the diameters of the optic sheath (OSD) and superior ophthalmic vein (SOVD) in response to positional changes using magnetic resonance imaging (MRI). MATERIALS AND METHODS: Fifty adult outpatients who presented to the hospital underwent thin-slice coronal T2-weighted MRI in the supine position followed by the prone position. RESULTS: The OS and SOV were well delineated in all the patients. The OSD in the anterior orbit was measured in the supine and prone positions on both sides. In addition, the SOVD in the anterior and posterior orbits was measured in the supine and prone positions on both sides. The OSD demonstrated an increase on both sides in 100% of the cases. The SOVD demonstrated an increase on both sides in 94% of the cases, whereas the remaining 6% demonstrated a decrease. The OSD measured at the anterior orbit and the SOVD at the anterior and posterior orbits significantly increased on both sides with positional changes from the supine to the prone position. CONCLUSION: OSD and SOVD may expand and contract in response to alterations in the intracranial pressure and venous flow patterns. MRI examination in the supine position combined with positional changes can help to better understand the OS and SOV as dynamic structures.

[Clinical features of acyclovir encephalopathy without acute kidney injury].

INTRODUCTION: Few reports have described acyclovir (ACV) encephalopathy without acute kidney injury (AKI). OBJECTIVE: This study clarified the clinical features of ACV encephalopathy without AKI compared to that with AKI. METHODS: Creatinine (Cre) levels were measured on admission. After admission, Cre was measured in a timely manner for the first seven hospital days. The minimum Cre level in these measurements was then determined. ACV encephalopathy was defined when two criteria were met: 1) neurological symptoms appeared after valacyclovir (VACV) administration, and 2) neurological symptoms improved after VACV discontinuation. AKI was defined when the Cre level on admission was >1.5 times higher than the minimum Cre level. The subjects were divided into AKI and non-AKI groups based on these findings. RESULTS: Eighteen patients had ACV encephalopathy (5 males, mean age 81.3±5.5 years old). All patients were prescribed VACV 3,000 mg/day. The minimum Cre was 1.93±1.76 mg/dL. AKI occurred in 10 (56.6%) patients. VACV was discontinued in all patients, and emergency hemodialysis treatment was administered in 10 (55.6%) patients. All patients recovered. Compared to the AKI group, the non-AKI group had a lower history of taking a Ca-blocker (33.3% vs 80.0%, p=0.092), a lower rate of emergency dialysis (16.9% vs 70.0%, p=0.059) and a longer time to clinical improvement (3.67±1.86 vs 2.20±0.63 days, p=0.073). CONCLUSION: ACV encephalopathy without AKI is characterized by a low rate of emergency dialysis, which may be linked to a prolonged duration of symptoms.

Are there characteristic indicators for increased pressure in chronic subdural hematoma?

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical disorders. However, no study has yet documented biomarkers indicating increased CSDH pressure. This study aimed to explore such indicators. A total of 50 patients underwent measurement for CSDH pressure during burr-hole irrigation. The mean hematoma pressure was 16.8 ± 7.6 cmH2O with no significant difference between new-onset and recurrent CSDHs. In 12 patients with a CSDH pressure ≥25 cmH2O, further analyses were carried out. Eight of them had bilateral CSDHs. All six patients with a CSDH pressure ≥28 cmH2O suffered headaches before surgery. Two out of three patients with a CSDH pressure ≥29 cmH2O felt nauseous. In statistical analyses, headache was positively correlated with a high CSDH pressure, whereas age and hematoma thickness were negatively correlated with it. Patients' sex, initial Glasgow coma scale score, motor weakness, midline shift on computed tomography scans, and administration of anticoagulants/antiplatelet agents, showed no significant correlation. When patients with bilateral CSDHs are not older adults and suffering headaches, an increased CSDH pressure should be assumed. For such patients, a prompt hematoma evacuation is indicated.

[A case of bilateral middle cerebellar peduncle infarction with hot cross bun sign].

A 71-year-old man with hypertension and diabetes mellitus presented to our hospital because he felt lightheaded. Diffusion-weighted images (DWI) on brain MRI showed high signal lesions in the left cerebellar hemisphere and the right pons. The diagnosis of cerebellar infarction was made, but he refused treatment. One month later, he came to our hospital because his body leaned to the left. Neurological examination revealed dysarthria and cerebellar truncal ataxia. An electrocardiogram showed atrial fibrillation. DWI on brain MRI showed high signal lesions in the bilateral cerebellar hemispheres and middle cerebellar peduncles (MCP). Dabigatran 300 |mg/day was administered for cardiogenic cerebral embolism. On the 12th day of onset, he was transferred to a rehabilitation hospital. At 72 years old, T2*-weighted images on brain MRI showed hot cross bun sign (HCBs) in the pons. We considered that HCBs were caused by antegrade or retrograde degeneration (or both) of pontine infarcts and bilateral MCP infarcts in the pontine cerebellar tract. It seemed preferable to use T2*-weighted images or proton density-weighted images rather than T2-weighted images to detect HCBs. When HCBs is detected, it should be noted that HCBs can be caused by bilateral MCP infarcts in addition to multiple system atrophy.

Acute epidural hemorrhage following burr-hole irrigation for chronic subdural hematoma: A possible association with the diploic veins.

A 50-year-old man presented with headache and left hemiparesis. No noticeable preceding head trauma was observed. Computed tomography (CT) scans revealed a compressive chronic subdural hematoma (CSDH). The patient underwent burr-hole irrigation, during which he was considerably restless. In addition, extensive avulsion was found in the parietal dura mater posterior to the burr hole. CT performed immediately after the surgery revealed the emergence of a thick epidural hematoma (EDH) located posterior to the burr-hole. During emergency craniotomy for the EDH, there was no identifiable injury to the dura mater or the meningeal vessels. However, a review of the CT scans confirmed well-developed diploic spaces just above the center of the EDH, with connecting channels between the diploic spaces and extracranial sites. Based on these observations, we assumed that the diploic vein might have caused the EDH. Diploic veins can cause AEDH after burr hole irrigation for CSDH. Appropriate intraoperative sedation and protective irrigation maneuvers can reduce the risk of such AEDH.

[Analysis of factors leading to brain MRI lesions in Wernicke's encephalopathy].

[Objective] To investigate association between Wernicke encephalopathy (WE) and brain MRI. [Subjects] 26 patients (7 females, mean age 63.9 ± 12.7 years) with WE admitted to our department between May 2008 and September 2022. [Methods] Wernicke's encephalopathy in patients with MRI lesions was defined as "MRI-positive group" (MPG), and those without MRI lesions as "MRI-negative group" (MNG). The following parameters were assessed between the two groups: age, sex, alcoholism, neurological symptoms, vitamin B1, lymphocyte, total cholesterol, albumin, and outcome at discharge. [Results] There were 17 patients in MPG. Compared to MNG, MPG had lower rates of alcohol abuse (10.0% vs 77.8%, P = 0.025), lower vitamin B1 (median 10.0 |ng/ml vs 29.0 |ng/ml, P < 0.001), and more vitamin B1 treatment dose (median 1900 |mg vs 600 |mg, P = 0.016). [Conclusion] Alcoholic WE may be overlooked if the focus is solely on brain MRI findings.

Idiopathic thoracic spinal cord herniation into the vertebra progressing for 3 years.

A 43-year-old, previously healthy man experienced a decreased sensation in the left lower extremity without preceding spinal trauma. At presentation, the patient exhibited slight motor weakness in the left lower extremity, in addition to decreased pain sensation below the ipsilateral T7. Spinal magnetic resonance imaging (MRI) revealed abnormal findings consistent with idiopathic thoracic spinal cord herniation (ITSCH) at the T5/6 level. Computed tomography (CT) revealed a small vertebral erosion at the lower T5. The patient's symptoms gradually progressed over the next 3 years. MRI revealed marked lateral elongation of the cord at the T5/6 and apparent intravertebral cord herniation. The patient underwent ITSCH reduction through T5-6 laminectomies. The herniated cord was vertically long with a bulbous rostral part. Successful ITSCH reduction was achieved and the patient's postoperative course was uneventful. ITSCH is a progressive pathology that requires prompt surgical reduction. Certain ITSCHs may be complicated by intravertebral cord herniation.

Dural-based large B-cell lymphoma masquerading as a tentorial meningioma.

A 53-year-old woman presented with a 2-week history of headache and vertigo. Computed tomography revealed a hyperdense tumor, measuring 30 × 31 × 36 mm in diameter, in the anteromedial parts of the cerebellar hemispheres. Cerebral magnetic resonance imaging 10 days later revealed an apparent extra-axial tumor with broad attachment to the medial tentorium cerebelli and rapid growth to a diameter of 40 × 41 × 46 mm. Cerebral angiography revealed no obvious feeding vessels or tumor stains. The patient underwent biopsy through the left occipital transtentorial route. The histological appearance was consistent with diffuse large B-cell lymphoma. Intracranial lymphoma may present as a dural tumor that mimics a meningioma. Rapid tumor growth incongruous with benign meningiomas should be assumed to be possible lymphoma, and prompt biopsy should be performed.

Ectopic pancreatic adenocarcinoma in Meckel's diverticulum: a case report.

BACKGROUND: Malignant neoplasms arising from Meckel's diverticulum are rare and an adenocarcinoma in Meckel's diverticulum originating from ectopic pancreatic tissue is even rarer. Herein, we report a patient with an ectopic pancreatic adenocarcinoma in Meckel's diverticulum who was successfully treated with surgery and chemotherapy. CASE PRESENTATION: A woman in her sixties presented to another hospital with abdominal pain. Plain computed tomography suggested an abdominal tumor and she was referred to our hospital. Enhanced computed tomography revealed a 23-mm low-density tumor in the abdominal cavity. Surgery was performed with a tentative diagnosis of a mesenteric tumor, such as a gastrointestinal stromal tumor, schwannoma, or lymphoma. First, we inspected the peritoneal cavity with a laparoscope. This revealed numerous nodules in the small bowel mesentery, suggesting peritoneal dissemination. A 20-mm-diameter white tumor was found in the small intestine and diagnosed as a small intestinal cancer. The small intestine was partially resected laparoscopically through a small skin incision. The patient's postoperative course was uneventful, and she was discharged on postoperative day 9. Pathological examination revealed well-differentiated adenocarcinoma in the small intestine. The tumor had developed from a sac-like portion protruding toward the serosal side and had a glandular structure lined with flattened atypical cells. Neither pancreatic acinar cells nor islets of Langerhans were evident, suggesting a Heinrich type 3 ectopic pancreas. The final diagnosis was an adenocarcinoma originating from an ectopic pancreas in Meckel's diverticulum. After a smooth recovery, the patient commenced chemotherapy for pancreatic cancer. CONCLUSIONS: We present a very rare case of ectopic pancreatic carcinoma in Meckel's diverticulum.

Trends in prior antithrombotic medication and risk of in-hospital mortality after spontaneous intracerebral hemorrhage: the J-ICH registry.

Spontaneous intracerebral hemorrhage (SICH) remains a devastating form of stroke. Prior use of antiplatelets or warfarin before SICH is associated with poor outcomes, but the effects of direct oral anticoagulants (DOACs) remain unclear. This study aimed to clarify trends in prior antithrombotic use and to assess the associations between prior use of antithrombotics and in-hospital mortality using a multicenter prospective registry in Japan. In total, 1085 patients were analyzed. Prior antithrombotic medication included antiplatelets in 14.2%, oral anticoagulants in 8.1%, and both in 1.8%. Prior warfarin use was significantly associated with in-hospital mortality (odds ratio [OR] 5.50, 95% confidence interval [CI] 1.30-23.26, P < 0.05) compared to no prior antithrombotic use. No such association was evident between prior DOAC use and no prior antithrombotic use (OR 1.34, 95% CI 0.44-4.05, P = 0.606). Concomitant use of antiplatelets and warfarin further increased the in-hospital mortality rate (37.5%) compared to warfarin alone (17.2%), but no such association was found for antiplatelets plus DOACs (8.3%) compared to DOACs alone (11.9%). Prior use of warfarin remains an independent risk factor for in-hospital mortality after SICH in the era of DOACs. Further strategies are warranted to reduce SICH among patients receiving oral anticoagulants and to prevent serious outcomes.