Cerebellar Contribution to Pattern Separation of Human Hippocampal Memory Circuits

The cerebellum is a crucial structure for cognitive function as well as motor control. Benign brain tumors such as schwannomas, meningiomas, and epidermoids tend to occur in the cerebellopontine angle cisterns and may cause compression of the posterior lateral cerebellum near the superior posterior fissure, where the eloquent area for cognitive function was recently identified. The present study examined cognitive impairment in patients with benign cerebellar tumors before and after surgical intervention in order to clarify the functional implications of this region in humans. Patients with cerebellar tumors showed deficits in psychomotor speed and working memory compared with healthy controls. Moreover, these impairments were more pronounced in patients with right cerebellar tumors. Functional magnetic resonance imaging during performance of a lure task also demonstrated that cerebellar tumors affected pattern separation or the ability to distinguish similar experiences of episodic memory or events with discrete, non-overlapping representations, which is one of the important cognitive functions related to the hippocampus. The present findings indicate that compression of the human posterior lateral cerebellum affects hippocampal memory function.     

Three-dimensional blood flow analysis in a wide-necked internal carotid artery-ophthalmic artery aneurysm

OBJECT: The aim of this study was to evaluate axial and secondary flow structures in a wide-necked internal carotid artery-ophthalmic artery aneurysm, one of the most common locations for endovascular coil placement. METHODS: A clear acrylic aneurysm model was manufactured from a three-dimensional computerized tomography angiogram. Intraaneurysm blood flow analysis was conducted using an acrylic aneurysm model together with laser Doppler velocimetry and particle imaging velocimetry. The maximal axial blood flow velocities in the inflow and outflow zones at the aneurysm orifice were noted at the peak systolic phase, measuring 46.8 and 24.9% of that in the parent artery, respectively. The mean size of the inflow zone during one cardiac cycle was 44.3 +/- 9.8% (range 35.6-58.7%) the size of the axial section at the aneurysm orifice. In the lower and upper planes of the aneurysm dome, the mean size of inward and outward flow areas were 43.3 +/- 6.7% and 43.8 +/- 6.8% the size of the axial cross-sectional plane, respectively. The axial flow velocity structures were dynamically altered throughout the cardiac cycle, particularly at the aneurysm orifice. The fastest secondary flow at the opening was also noted at the peak systolic and early diastolic phases. Axial blood flow velocity was slower in the upper axial plane of the aneurysm dome than in the lower one. Conversely, the secondary flow component was faster in the upper plane. CONCLUSIONS: The side-wall aneurysm in this study did not demonstrate a simple flow pattern as was previously seen in ideally shaped experimental aneurysms in vitro and in vivo. The flow patterns of inflow and outflow zones were very difficult to predict based on the limited flow information provided on standard digital subtraction angiography, even in an aneurysm with a relatively simple dome shape.     

Pineal xanthogranuloma

A 64-year-old man presented a large pineal cystic lesion manifesting as headache and exhibiting unusual neuroradiological findings. Magnetic resonance imaging showed a cystic lesion appearing as hyperintense on both T1- and T2-weighted images, and a nodular lesion which was hypointense on T1-and mixed intensity on T2-weighted images. The cystic mass was removed via a right occipital transtentorial approach. Histological examination disclosed that the inner surface of the cystic part consisted of bi-layered epithelial lining, portions of which had changed to stratified squamous epithelium. The solid part showed the characteristics of xanthogranuloma such as cholesterol clefts, hemosiderin-laden macrophages, and foreign body giant cells.     

Effects of atorvastatin on renal function in patients with dyslipidemia and chronic kidney disease: assessment of clinical usefulness in CKD patients with atorvastatin (ASUCA) trial

Background

Dyslipidemia is a risk factor for the progression of chronic kidney disease (CKD). While conventional lipid lowering therapy provides a benefit to CKD management, the effect of statins on eGFR remains unclear.

Methods

A prospective, multi-center, open-labeled, randomized trial. Total of 349 CKD patients with hyperlipidemia were randomized into 2 groups, and followed for 2 years. Group A included patients who were treated with atorvastatin. Group C were treated with conventional lipid lowering drugs other than statin. Primary endpoint was changes in eGFR. Secondary endpoints included changes in urinary albumin excretion, serum LDL-C, serum triglyceride, cardio-vascular events and all-cause mortality.

Results

As the primary endpoint, eGFR decreased by 2.3 ml/min/1.73 m² in Group A and by 2.6 ml/min/1.73 m² in Group C, indicating that there was no difference in change of eGFR between the two groups. As secondary endpoints, atorvastatin succeeded to reduce serum LDL-C level significantly and rapidly, but conventional therapy did not. In fact, mean LDL-C level did not reach the target level of 100 mg/dl in Group C. Serum triglyceride was lowered only by atorvastatin, but not conventional drugs. The number of cardiovascular events and all-cause mortality did not differ between in two groups.

Conclusion

The ASUCA (Assessment of Clinical Usefulness in CKD Patients with Atorvastatin) trial demonstrated that atorvastatin failed to exhibit reno-protections compared to conventional therapy in Japanese patients with dyslipidemia and CKD. It would be due in part to the ability of atorvastatin to more potently reduce serum LDL and triglycerides compared to conventional therapy.

     

Quantification of retinal nerve fiber layer thickness reduction associated with a relative afferent pupillary defect in asymmetric glaucoma

AIM: The relative afferent pupillary defect (RAPD) is an important clinical sign of asymmetrical retinal ganglion cell and axonal damage. Although glaucoma essentially affects bilateral eyes, a subset of patients manifests asymmetrical glaucomatous optic neuropathy (GON), which exhibits an RPAD in the more advanced eyes. However, the degree to which axonal loss occurs before an RAPD is clinically detectable has not been substantiated. The purpose of this study is to assess the relationship between the depth of a clinically detectable RAPD and the reduction ratio of retinal nerve fiber layer (RNFL) thickness in the more advanced eyes relative to that in the contralateral less advanced eyes of patients with asymmetrical GON. METHODS: Enrolled were 29 consecutive glaucoma patients with the clinically detectable RAPD. An RAPD was quantified by placing log-scaled neutral density filters over the less advanced eyes while performing the swinging flashlight test. Average RNFL thickness was determined using the Fast RNFL thickness programme of optical coherence tomography 3000. Correlation coefficient and Linear regression analyses were used in assessing the relationship between the RAPD and the ratio of RNFL thickness in the more advanced eyes relative to that in the less advanced. RESULTS: RAPD ranged from 0.6 to 2.4 log units. The log-scaled RAPD had a statistically significantly inversed correlation with the average RNFL thickness ratio (r(s) = -0.729, p<0.0001). Linear regression analysis found an equation that the average RNFL thickness ratio in the more affected eyes relative to that in the less advanced (%) = (0.827-0.169xRAPD (log units))x100 (R(2) = 0.557, p<0.0001). CONCLUSIONS: When an RAPD is clinically detected, the RNFL thickness in the more advanced eyes was in average reduced to about 73% of that in the less advanced.     

A comparative study of the effects of drug therapy and bladder training therapy

Treatment of enuresis was studied in 168 patients. The patients were divided into two groups, the drug therapy group which consisted of 88 patients who were treated with drugs only, and the bladder training therapy group which consisted of 80 patients who were treated mainly with bladder training supplemented with drug therapy. In the drug therapy group imipramine was the first choice and was used at bed time. The dose of imipramine was initially 1 mg/kg and was gradually decreased if it worked well, and changed to other drugs if it did not work well. In the bladder training therapy group, bladder training was performed in all patients for 3 months, and 22 patients who cured further bladder training was continued, whereas the rest of the patients (58 patients) drug therapy was started in addition to bladder training. After 3 months, drug therapy was effective for 54 patients (61%) including 10 patients (11%) who were cured, and bladder training therapy plus drug therapy was effective for 55 patients (69%) including 22 patients (28%) who were cured. The number of cured patients in the bladder training therapy group was significantly larger than that of the drug therapy group (p less than 0.01). After 6 months, drug therapy was effective for 56 patients (64%) including 16 patients (18%) who were cured, and bladder training therapy plus drug therapy was effective for 66 patients (83%) including 30 patients (38%) who were cured. The number of effective and cured patients in the bladder training therapy group was significantly larger than that in the drug therapy group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transurethral resection of bladder neck in female patients with neurogenic bladder

Transurethral resection of the bladder neck was performed in 6 female patients with neurogenic bladders who presented with a large volume of residual urine and bladder neck obstruction on voiding cystourethrography without detrusor hyperreflexia on cystometry. In 4 of the patients, transurethral sphincterotomy was performed concomitantly. Five of the patients demonstrated significant improvement in bladder emptying and 4 did not need self-catheterization. No complications of the operation were observed.     

Hemangioma located just above the left main coronary artery, in a subject who had cardiac arrest due to ventricular fibrillation, led to a diagnosis of Brugada syndrome

We report the case of a 38-year-old Asian man with a pericardial hemangioma on the left main coronary artery. The patient presented initially at our hospital after cardiopulmonary resuscitation following an episode of ventricular fibrillation (VF). Because of spontaneous coved-type ST segment elevation on the higher intercostal space V1 to V2 in a 12-lead electrocardiogram, documented VF in the absence of structural heart disease, and a family history of sudden death, he was diagnosed with Brugada syndrome. Transesophageal echocardiography showed a smooth-surfaced mass with well-demarcated borders, directly above the left main coronary artery. Computed tomography confirmed the presence of the mass, which showed no enhancement at early phase, but did demonstrate homogenous enhancement at delay phase by contrast material. There were no findings from either the nuclear medicine or the tumor marker investigations which indicated that the mass located just above the main coronary arteries was malignant. Therefore, taken together, these findings suggested that the tumor might be a pericardial hemangioma. The relationship between the location of the hemangioma just above the left main coronary artery and the occurrence of VF was not clear, i.e. whether the presence of the hemangioma caused the stimulation of the left main coronary artery and as a result, led to the spasm of the left main coronary artery and the occurrence of VF. Furthermore, as the tumor did not extend into any of the adjacent structures, such as the coronary arteries or the right ventricular outflow tract, surgical resection was not performed; instead, the patient received a dual chamber implantable cardioverter-defibrillator.