Large vessel vasculitis in elderly patients: early diagnosis and steroid-response evaluation with FDG-PET/CT and contrast-enhanced CT

Large vessel vasculitis (LVV) is an often-reported cause of inflammation of unknown origin (IUO) in elderly people. The objective of this study was to describe the usefulness of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and contrast-enhanced CT in early diagnosis and treatment follow-up of patients with LVV presenting as elderly onset IUO. We retrospectively compared contrast-enhanced CT findings and FDG-PET/CT findings of the patients diagnosed with LVV and 11 controls; all subjects were 50 years of age or older. We evaluated maximum standardised uptake value (SUV_max) and PET score of the aortic wall for quantitative comparison of FDG-PET/CT findings. We measured the aortic wall thickness (W) and its ratio against the radius (W/R) for quantitative comparison of aortic wall thickening by contrast-enhanced CT. After steroid treatment, we compared these values with those pre-treatment. Of 124 patients who were hospitalised due to advanced age and IUO, 88 underwent FDG-PET/CT and contrast-enhanced CT. Abnormal findings were observed on images from 78 patients. The findings were indicative of LVV in 13 patients (10.5 %), of whom more than half had only non-specific symptoms. Patients with LVV had significantly higher aortic wall SUV_max (3.85 vs. 1.95), PET scores by FDG-PET/CT, and aortic wall thicknesses by contrast-enhanced CT (3.8 vs. 2.6 mm) than controls. Significant improvement in aortic wall thickening was evidenced by reduced PET scores and by contrast-enhanced CT findings in patients who were followed up after treatment. LVV is an important cause of IUO with non-specific symptoms in elderly patients. Imaging examination comprising contrast-enhanced CT and FDG-PET/CT is useful for early diagnosis and early treatment evaluation of LVV, allowing for amelioration of reversible aortic wall thickening.     

Monitoring and switching of cortico-basal ganglia loop functions by the thalamo-striatal system

Recent physiological and tract tracing studies revealed tight coupling of the centre médian and parafascicular nuclei (the CM-Pf complex), which are posterior intralaminar nuclei (ILN) of the thalamus, with basal ganglia circuits. These nuclei have previously been classified as part of the ascending reticulo-thalamo-cortical activating system, with studies of single neuron activity and of interruption of neuronal activity suggested that they participate in the processes of sensory event-driven attention and arousal, particularly in the context of unpredicted events or events contrary to predictions. In this article, we propose a hypothetical model that envisions that the CM-Pf complex functions in two different modes depending on the predictability of external events, i.e., one for monitoring 'top-down' biased control through the cortico-basal ganglia loop system for selecting signals for action and cognition and the other for switching from biased control to 'bottom-up' control based on the signals of salient external events. This model provides a new insight into the function of the CM-Pf complex and should lead to a better understanding of this important brain system.     

Surgical outcome of radial osteotomy for Kienböck's disease-minimum 10 years of follow-up

PURPOSE: Long-term results of radial osteotomy for Kienb?ck's disease seldom are seen in the literature. The purpose of this study was to report the minimum 10-year results and to compare them with the 5-year results to determine whether the favorable intermediate-term results were maintained. METHODS: Twenty-five patients who underwent radial osteotomy were followed-up for a mean period of 14.5 years. They were examined for pain, grip strength, and wrist range of motion (ROM). Through a review of clinical records, 5-year postoperative results were collected. The carpal height ratio and St?hl's index were measured and the x-rays were inspected for osteoarthritic changes. We devised an original lunate grade to evaluate radiologic improvement of the ischemic lunate. Overall results were evaluated using Cooney's wrist function score and Nakamura's scoring system for Kienb?ck's disease. The long-term results were compared with both the preoperative status and the 5-year results. RESULTS: Pain, ROM, and grip strength were improved significantly after surgery, and the results were maintained for a long period. Carpal height ratio and St?hl's index did not show significant improvements but ischemic lunate showed certain radiologic improvements with time by the lunate grade system. Osteoarthritic changes were observed in 54% of patients at 5 years and in 73% of patients at the final follow-up evaluation, but the arthrosis generally was mild and did not affect the clinical results. Cooney's wrist function score was excellent or good in 96% of the patients, and the results with Nakamura's scoring system for Kienb?ck's disease were excellent or good in 68% of the patients at the final follow-up evaluation. The percentages were the same 5 years after surgery. CONCLUSIONS: Radial osteotomy for Kienb?ck's disease is a reasonable treatment option and clinical improvement lasts for a long period of time. Although radiologic improvement was not drastic, the inner structure such as sclerotic change or bone cysts of the lunate improved with time, indicating healing of the ischemic lunate. Severe osteoarthritic change or proximal migration of the capitate can be avoided.     

Sonographic diagnosis of acute injuries of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb

PURPOSE: To evaluate the significance of the ultrasonographic appearance of the aponeurosis for deciding the best treatment for ulnar collateral ligament (UCL) injuries of the thumb metacarpophalangeal joint. METHODS: Fourteen patients (11 men, 3 women; mean age, 41 years; range, 15-66 years) who had an acute UCL tear were included. All patients were examined by ultrasonography (US) with a 7.5-MHz transducer and subsequently underwent surgery. The ultrasonographic findings were compared to the intraoperative findings. RESULTS: UCL injuries were classified into two types by US according to the appearance of aponeurosis and its spatial relationship with the UCL: the intra-aponeurosis type (5 patients) and the extra-aponeurosis type (9 patients). In the 5 patients with intra-aponeurosis, ultrasonographic findings were well consistent with intraoperative findings. In contrast, extra-aponeurosis cases contained two different pathologies: of the 9 patients, 7 had so-called 'Stener lesions', one showed folding of a ruptured capsule, and one showed a ruptured aponeurosis. CONCLUSIONS: Because US is highly reliable in differentiating intra-aponeurosis from extra-aponeurosis types of injuries, the aponeurosis is a more reliable reference than Stener lesion for treatment decision by US.     

Axonal regeneration from the spinal cord to peripheral nerve induced by end-to-side neurorrhaphy Evidence from acetylcholinesterase staining and Fluorogold retrograde tracing

BACKGROUND： In recent years, surgeons have advocated root or trunk repair of avulsed nerve roots for overall recovery. However, donor nerves pose a major problem, because they do not contain adequate numbers of axons. Moreover, the procedures lead to nerve deficits in the donor nerve following transplantation. OBJECTIVE： To observe whether axonal regeneration occurs by end-to-side neurorrhaphy in the peripheral nerve and spinal cord. DESIGN, TIME AND SETTING： A neuroanatomical, randomized, controlled, animal study was performed at Functional Anatomy Lab in Nagoya University School of Medicine from May 2002 to July 2003. MATERIALS： Fluorogold was purchased from Fluorochrome, LLC, USA. BX50 light microscope and fluorescent microscope were purchased from Olympus, Japan. METHODS： A total of 21 rats were randomly divided into three groups, and the posterior avulsion injury model （C6-8） of the brachial plexus was performed. In the ventral root graft group, the avulsed C7 ventral roots were reanastomosed to the small anterior lateral aspect window of the spinal cord via nerve grafts. In the dorsal root graft group, the C7 dorsal roots were reanastomosed at the small pia mater window of the posterior lateral aspect of the spinal cord via nerve grafts. In the control group, the avulsed nerve roots were not repaired. MAIN OUTCOME MEASURES： The nerve grafts were collected from the ventral and dorsal root graft groups, and the C7 proximal nerve end was collected from the control group. Acetylcholinesterase staining was performed on the tissue. Fluorogold retrograde tracing technique was applied to determine the origin of the regenerating axons. RESULTS： Results showed that acetylcholine-positive axons existed in nerve grafts of the ventral and dorsal root graft groups. However, axons were not found in the avulsed nerve roots of the control group. Fluorogold retrograde tracing confirmed the presence of fluorogold-containing neurons in the ventral and dorsal horn of the ventral and dorsal root graft groups. Fluorogold-positive neurons were not observed in the control group. CONCLUSION： End-to-side neurorrhaphy induced axonal regeneration from the spinal cord to the peripheral nervous system.     

Elasticity of the supraspinatus tendon-muscle unit is preserved after acute tendon tearing in the rabbit

Supraspinatus tendon tearing is one of the most common causes of the shoulder pain and dysfunction, which often requires a surgical repair. In this situation, proximal tendon stump is usually retracted medially from its original insertion. For successful reduction of the retracted tendon stump to its original insertion, the elasticity of the tendon-muscle unit should be preserved by the time of surgery. The purpose of the present study was to clarify the chronological changes in the elasticity of the supraspinatus tendon-muscle unit after acute tendon tearing to determine the optimal timing for the surgery. Right supraspinatus tendon was detached (detached side) in 40 male Japanese white rabbits, with left shoulders served as controls (control side). Eight animals were euthanized at 3 days and 1, 2, 4, or 8 weeks after surgery. Tissue sound speed that closely correlates to its elasticity was measured with a scanning acoustic microscope. In the supraspinatus tendon, tissue sound speed at 3 days after surgery was 1691.1 m/s, compared to 1714.3 m/s at the control side, but the difference was not statistically significant at any postoperative time period up to 8 weeks. In the supraspinatus muscle, tissue sound speed was not affected at all by the detachment of the tendon. The present study indicated that the elasticity of the supraspinatus tendon-muscle unit was well preserved for 8 weeks after the detachment. In the clinical practice, the retracted supraspinatus tendon stump could be repaired without excessive tension by 8 weeks from the acute tendon tearing.