Comparative Analysis of Patients Undergoing Microvascular Decompression for Trigeminal Neuralgia Caused by Solely Arterial or Solely Venous Compression.

OBJECTIVE: Trigeminal neuralgia (TN) due to venous compression is far less common than that due to arterial compression, and its pathogenesis is less clear. We investigated the clinical and imaging features of TN caused by solely venous compression by measuring the morphologies of the posterior cranial fossa (PCF) and the trigeminal nerve. METHODS: We retrospectively reviewed records of TN patients who underwent microvascular decompression at our institution and extracted cases with solely arterial or solely venous compression. Preoperative magnetic resonance imaging was used to find the length (Y), width (X), height (Z), and volume (V) of the PCF, the angle between the trigeminal nerve and pons, and the distance between Meckel's cave and the root entry zone of the trigeminal nerve. RESULTS: Of 152 patients, 24 had TN caused solely by venous compression. The value of Y was significantly smaller in the venous group than the arterial group (P < 0.01). The trigeminal nerve and pons was significantly smaller in the venous group (P < 0.01). We hypothesized that TN patients with solely venous compression had a characteristic PCF morphology with a short anteroposterior diameter (Y), such that age-related changes in brain morphology could alter the course of the trigeminal nerve and cause compression by a vein. CONCLUSIONS: The morphological features of the PCF differed between patients with TN of venous and those with TN of arterial etiology. Age-related changes in brain morphology and changes of course of the trigeminal nerve may also add to the possibility of developing TN, especially of venous etiology.

Validity of the Cost-Effectiveness of Middle Meningeal Artery Embolization Following Hematoma Evacuation for Initial Chronic Subdural Hematoma.

BACKGROUND: Despite numerous articles about middle meningeal artery embolization (MMAE) highlighting its efficacy and safety for recurrent chronic subdural hematoma (CSDH), the appropriateness of adjunctive MMAE after hematoma evacuation for initial CSDH remains unclear from a cost-effectiveness perspective. METHODS: Patients with CSDH were enrolled in this study and were prospectively divided into 2 groups: the "conventional treatment" group, which was treated with hematoma evacuation alone, and the "MMAE" group, which was treated with adjunctive MMAE after hematoma evacuation. The proportion of patients requiring retreatment, length of hospital stay, economic costs, and modified Rankin Score were compared between the 2 groups. RESULTS: In this study, 53 cases were included, with 30 classified into the conventional treatment group and 23 classified into the MMAE group. In the conventional treatment group, the proportion of patients who required surgical retreatment was higher than that in the MMAE group (16.7% vs. 8.7%). The relative risk was 0.522 (95% confidence interval, 0.111-2.45). Although the addition of MMAE increased the cost per hospitalization by 26%, the increase in cost per patient was limited to 12%, owing to the reduction in patients who relapsed and required a second hospitalization. The increase in cost was not statistically significant. The MMAE group had a significantly higher proportion of patients with favorable outcomes (modified Rankin Score 0-2) (56.7% vs. 87.0%, P = 0.0328). CONCLUSIONS: By minimizing the increase in hospitalization days and procedure costs, MMAE following hematoma evacuation for initial CSDH could decrease the retreatment rate and balance the total medical costs associated with MMAE.

Solitary pulmonary nodule caused by pulmonary Mycobacterium lentiflavum infection.

An 82-year-old Japanese man who previously had descending colon cancer and underwent partial resection showed a growing solitary pulmonary nodule, suspected as lung cancer, on follow-up computed tomography. Thoracoscopic partial lobectomy was therefore performed. The surgical specimen showed granulomatous lesions with necrosis. Mass spectrometry was performed on the sputum specimen collected after surgery, which identified Mycobacterium lentiflavum infection. Antibiotics were not prescribed following surgery, and the patient has not experienced recurrence 2 years since the surgery. To our knowledge, this is the second case of solitary pulmonary nodule and the first case of M. lentiflavum infection treated via surgical resection.

Atypical Histological Features as Risk Factors for Recurrence in Newly Diagnosed WHO Grade I Meningioma.

The significance of atypical histological features (AHF) as risk factors for recurrence in benign meningioma is not well understood. This study examined risk factors of World Health Organization (WHO) Grade I meningioma (GIM) recurrence, focusing on AHF. We investigated 150 consecutive newly diagnosed GIM patients who had more than one year of follow-up after resection in our hospital between January 2007 and March 2018. The following factors were reviewed retrospectively: age, sex, tumor location, extent of resection, MIB-1 index, mitotic figures, number and distribution of AHF, and recurrence. The patients were grouped according to the presence or absence of recurrence and comparatively examined. Recurrence was observed in 10 cases (6.7%). Univariate analysis showed that patients with recurrence had a significantly higher MIB-1 index (2.0 vs. 4.3; p = 0.006) and a significantly higher proportion of male patients (21.4% vs. 70.0%; p = 0.002) and patients with sheet-like growth (6.42% vs. 30.0%; p = 0.04). In multivariate analysis, skull base location (odds ratio [OR] 31.424; 95% confidence interval [CI] 1.74-569), gross total resection (OR 0.130; 95% CI 0.0189-0.897), and MIB-1 index (OR 1.939; 95% CI 1.19-3.15) were significantly associated with recurrence. Our study revealed that skull base location, subtotal resection, and high MIB-1 index were independent risk factors for recurrence. Only the presence of sheet-like growth had a significantly higher incidence in patients with recurrence in univariate analysis of AHF. Multivariate analysis found no significant association. Sheet-like growth may be involved in malignancy and recurrence of benign meningioma.

Analysis of SARS-CoV-2 PCR and Chest CT Findings at a Single Facility in Tokyo (Machida Municipal Hospital).

INTRODUCTION: The SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) test is useful for diagnosing COVID-19, and the RT-PCR positive rate is an important indicator for estimating the incidence rate and number of infections. COVID-19 pneumonia is also associated with characteristic findings on chest CT, which can aid in diagnosis. METHODS: We retrospectively evaluated patient background characteristics, the number of cases, the positivity rate, and chest CT findings for positive and negative cases in 672 patients who underwent RT-PCR for suspected COVID-19 at our hospital between April 3 and August 28, 2020. In addition, we compared trends in the positive rates at approximately weekly intervals with trends in the number of new infections in Machida City, Tokyo. RESULTS: The study included 323 men and 349 women, with a median age of 46 years (range: 1 month-100 years). RT-PCR findings were positive in 37 cases, and the positive rate was 5.51%. Trends in the positive rate at our hospital and the number of new COVID-19 cases in the city were similar during the study period. Among patients with positive results, 15 (40.5%) had chest CT findings, and 14 had bilateral homogeneous GGOs. Among patients with negative results, 190 had chest CT findings at the time of examination, and 150 were diagnosed with bacterial pneumonia or bronchitis, with main findings consisting of consolidations and centrilobular opacities. Only 11 of these patients exhibited bilateral homogeneous GGOs. CONCLUSION: Bilateral homogeneous GGOs are characteristic of COVID-19 pneumonia and may aid in the diagnosis of COVID-19.

Clinical utility of thoracoscopy in elderly tuberculous pleurisy patients under local anesthesia.

INTRODUCTION: Diagnosing tuberculous pleurisy is important in Japan because it currently has a moderate tuberculosis prevalence. However, physicians often have difficulty making a diagnosis. It was reported that thoracoscopy under local anesthesia is useful for the diagnosis of tuberculous pleurisy, but there are no reports focusing on elderly patients. METHODS: In this study, the usefulness of thoracoscopy under local anesthesia was evaluated in elderly patients. Among 170 patients who underwent thoracoscopy under local anesthesia at our hospital during 11 years from January 2008 to December 2018, those aged 75 years or older (n = 75) were investigated retrospectively. RESULTS: A total of 55 patients underwent thoracoscopy under local anesthesia for detailed examination of pleural effusion of unknown cause. Of these, 18 were diagnosed as tuberculous pleurisy. The median age was 82 years (range: 75-92 years). The diagnosis of tuberculous pleurisy was made in 11 patients in whom Mycobacterium tuberculosis was detected and in four patients whose pathological findings indicated epithelioid granuloma accompanied by caseous necrosis. Clinical diagnosis was made in the remaining three patients based on thoracoscopic findings of the pleural cavity and a high level of adenosine deaminase in pleural fluid. No serious complications attributable to the examination were observed in any patient. CONCLUSIONS: Thoracoscopy under local anesthesia was useful for the diagnosis of tuberculous pleurisy in elderly patients, with useful information being also obtained for the treatment of tuberculosis.

Impact of emphysema on sputum culture conversion in male patients with pulmonary tuberculosis: a retrospective analysis.

BACKGROUND: Although cigarette smoking may have a negative impact on the clinical outcome of pulmonary tuberculosis (PTB), few studies have investigated the impact of smoking-associated lung diseases. Emphysema is a major pathological finding of smoking-related lung damage. We aimed to clarify the effect of emphysema on sputum culture conversion rate for Mycobacterium tuberculosis (MTB). METHODS: We retrospectively studied 79 male patients with PTB confirmed by acid-fast bacillus smear and culture at Jikei University Daisan Hospital between January 2015 and December 2018. We investigated the sputum culture conversion rates for MTB after starting standard anti-TB treatment in patients with or without emphysema. Emphysema was defined as Goddard score ≥ 1 based on low attenuation area < - 950 Hounsfield Unit (HU) using computed tomography (CT). We also evaluated the effect on PTB-related CT findings prior to anti-TB treatment. RESULTS: Mycobacterial median time to culture conversion (TCC) in 38 PTB patients with emphysema was 52.0 days [interquartile range (IQR) 29.0-66.0 days], which was significantly delayed compared with that in 41 patients without emphysema (28.0 days, IQR 14.0-42.0 days) (p < 0.001, log-rank test). Multivariate Cox proportional hazards analysis showed that the following were associated with delayed TCC: emphysema [hazard ratio (HR): 2.43; 95% confidence interval (CI): 1.18-4.97; p = 0.015), cavities (HR: 2.15; 95% CI: 1.83-3.89; p = 0.012) and baseline time to TB detection within 2 weeks (HR: 2.95; 95% CI: 1.64-5.31; p < 0.0001). Cavities and consolidation were more often identified by CT in PTB patients with than without emphysema (71.05% vs 43.90%; p = 0.015, and 84.21% vs 60.98%; p = 0.021, respectively). CONCLUSIONS: This study suggests that emphysema poses an increased risk of delayed TCC in PTB. Emphysema detection by CT might be a useful method for prediction of the duration of PTB treatment required for sputum negative conversion.

Muscular-stage Dissection during Far Lateral Approach and Its Transcondylar Extension.

Background The far lateral approach includes exposure of the C1 transverse process, vertebral artery, posterior arch of the atlas, and occipital condyle. We designed a method for systematic muscular-stage dissection and present our experience with this approach. Operative Methods We used a horseshoe scalp flap that was reflected downward and medially. The lateral muscle layers were separated layer to layer to expose the suboccipital triangle. The medial muscle layers were separated in the midline and reflected in a single layer. At this stage, the midline of the C1 process and the foramen magnum were identified. The rectus capitis posterior major muscle was reflected to expose the posterior arch of the atlas. The C1 transverse process and vertebral artery were identified by reflection of the superior oblique muscle. The occipital condyle was separated accordingly. Results We used this method of muscular dissection in 10 patients (foramen magnum meningioma, n = 5; hypoglossal schwannoma, n = 2; others, n = 3). Systematic muscular-stage dissection facilitates identification of the anatomical landmarks with no vertebral artery injury. Gross total removal was obtained in all 9 patients with complex tumors. The patient with vertebral artery dissection successfully underwent proximal clipping. Conclusion Our muscular-stage dissection could contribute to safe and effective surgery for the far lateral approach.

Chronologic Evaluation of Cerebral Hemodynamics by Dynamic Susceptibility Contrast Magnetic Resonance Imaging After Indirect Bypass Surgery for Moyamoya Disease.

OBJECTIVE: Although indirect bypass surgery is an effective treatment option for patients with ischemic-onset moyamoya disease (MMD), the time point after surgery at which the patient's hemodynamic status starts to improve and the time point at which the improvement reaches a maximum have not been known. The objective of the present study is to evaluate the hemodynamic status time course after indirect bypass surgery for MMD, using dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI). METHODS: We retrospectively analyzed the cases of 25 patients with MMD (37 sides; mean age, 14.7 years; range, 3-36 years) who underwent indirect bypass surgery and repeated DSC-MRI measurement within 6 months after the operation. The difference in the mean transit time (MTT) between the target regions and the control region (cerebellum) was termed the MTT delay, and we measured the MTT delay's chronologic changes after surgery. RESULTS: The postoperative MTT delay was 1.81 ± 1.16 seconds within 1 week after surgery, 1.57 ± 1.01 at weeks 1-2, 1.55 ± 0.68 at weeks 2-4, 1.32 ± 0.68 at months 1-2, 0.95 ± 0.32 at months 2-3, and 0.77 ± 0.33 at months 3-6. Compared with the preoperative value (2.11 ± 0.98 seconds), the MTT delay decreased significantly from 2 to 4 weeks after surgery (P < 0.05). CONCLUSIONS: The amelioration of cerebral hemodynamics by indirect bypass surgery began soon after surgery and gradually reached a maximum at 3 months after surgery. DSC-MRI detected small changes in hemodynamic improvement, which are suspected to be caused by the initiation of angiogenesis and arteriogenesis in the early postoperative period.

Mild Lung Tuberculosis in a Patient Suffering from Status Epilepticus Caused by the Syndrome of Inappropriate Secretion of Antidiuretic Hormone (SIADH).

A 76-year-old woman was diagnosed with lung tuberculosis. On the second day of anti-tuberculosis treatment, she became unconscious and developed status epilepticus accompanied by hyponatremia. The hyponatremia was caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Detailed examinations revealed that the patient's status epilepticus had occurred due to hyponatremia, which was caused by lung tuberculosis-associated SIADH. Previous case reports noted that patients with tuberculosis-associated SIADH showed mild clinical manifestations. They also reported that extensive lung involvement was associated with SIADH development. We herein report a rare case of SIADH complicated with status epilepticus that was caused by tuberculosis with mild lung involvement.