Decoding the individual finger movements from single‐trial functional magnetic resonance imaging recordings of human brain activity

Multivariate pattern classification analysis (MVPA) has been applied to functional magnetic resonance imaging (fMRI) data to decode brain states from spatially distributed activation patterns. Decoding upper limb movements from non‐invasively recorded human brain activation is crucial for implementing a brain–machine interface that directly harnesses an individual's thoughts to control external devices or computers. The aim of this study was to decode the individual finger movements from fMRI single‐trial data. Thirteen healthy human subjects participated in a visually cued delayed finger movement task, and only one slight button press was performed in each trial. Using MVPA, the decoding accuracy (DA) was computed separately for the different motor‐related regions of interest. For the construction of feature vectors, the feature vectors from two successive volumes in the image series for a trial were concatenated. With these spatial–temporal feature vectors, we obtained a 63.1% average DA (84.7% for the best subject) for the contralateral primary somatosensory cortex and a 46.0% average DA (71.0% for the best subject) for the contralateral primary motor cortex; both of these values were significantly above the chance level (20%). In addition, we implemented searchlight MVPA to search for informative regions in an unbiased manner across the whole brain. Furthermore, by applying searchlight MVPA to each volume of a trial, we visually demonstrated the information for decoding, both spatially and temporally. The results suggest that the non‐invasive fMRI technique may provide informative features for decoding individual finger movements and the potential of developing an fMRI‐based brain–machine interface for finger movement.     

虎口掌侧动脉背侧穿支蒂跨区供血皮瓣的解剖基础

目的　探讨虎口掌侧动脉背侧穿支形态学特征,为虎口掌侧动脉背侧穿支皮瓣设计提供解剖学基础。 方法　用30侧灌注红色乳胶的成尸手标本,通过巨微解剖、血管铸型等方法,重点观测：①虎口背侧营养血管的起源、走行与分布;②虎口掌侧动脉背侧穿支与虎口背侧血管的吻合特点。另1侧灌注红色乳胶的新鲜标本进行摹拟手术设计。 结果　虎口背侧血供属多源性,由虎口掌侧动脉（示指桡掌侧固有动脉、拇指尺掌侧固有动脉）背侧穿支和虎口背侧动脉（第1掌背动脉）分支供养。①第1掌背动脉恒定起自桡动脉,走行于第1掌骨间隙,分出桡侧、尺侧和中间3个终支,有桡神经浅支发出的同名指背皮神经伴行;②虎口掌侧动脉向虎口背侧发出尺侧、中间和桡侧穿支,与第1掌背动脉分支形成恒定的吻合,营养虎口背侧皮肤。 结论　以虎口掌侧动脉背侧穿支为蒂,可形成跨区域供血虎口背侧皮瓣转位修复示指近侧段、鱼际部和拇指软组织缺损。     

Histopathology of tenosynovium in trigger fingers

Stenosing flexor tenosynovitis, trigger finger, is a common clinical disorder causing painful locking or contracture of the involved digits, and most instances are idiopathic. This problem is generally caused by a size mismatch between the swollen flexor tendon and the thickened first annular pulley. Although hypertrophic pulleys have been histologically and ultrasonographically detected, little is known about the histopathology of the tenosynovium covering the tendons of trigger fingers. We identified chondrocytoid cells that produced hyaluronic acid in 23 (61%) fingers and hypocellular collagen matrix in 32 (84%) fingers around the tenosynovium among 38 specimens of tenosynovium from patients with trigger fingers. These chondrocytoid cells expressed the synovial B cell marker CD44, but not the chondrocyte marker S‐100 protein. The incidence of these findings was much higher than that of conventional findings of synovitis, such as inflammatory infiltrate (37%), increased vascularity (37%), hyperplasia of synovial lining cells (21%), or fibrin exudation (5%). We discovered the following distinctive histopathological features of trigger finger: hyaluronic acid‐producing chondrocytoid cells originated from fibroblastic synovial B cells, and a hypocellular collagen matrix surrounding the tenosynovium. Thus, an edematous extracellular matrix with active hyaluronic acid synthesis might increase pressure under the pulley and contribute to the progression of stenosis.     

上肢微型游离皮瓣在外伤性手指创面修复中的效果及对手部功能改善价值分析

目的探讨上肢微型游离皮瓣在外伤性手指创面修复中的效果及对手部功能的改善价值.方法选取我院2016年1月至2019年9月收治的100例手指外伤患者为研究对象,根据手术方式分为肢微型游离皮瓣修复组(试验组n=50例)和腹部皮瓣修复组(对照组n=50例).比较两组术后皮瓣存活情况、手部功能改善情况及术后并发症的发生率.结果术后试验组的皮瓣存活良好率为为94%高于对照组80%(P<0.05),手部功能优良率试验组为98%高于对照组86%(P<0.05),术后试验组的并发症发生率为12%,对照组为16%,但组间比较,差异无统计学意义(P>0.05).结论上肢微型游离皮瓣能提高外伤性手指创面修复效果,有效改善患者手部功能,且不增加术后并发症的发生率.     

An isolated digital lipoblastoma

Abstract

This report presents a girl with a lipoblastoma of a finger presenting as a macrodactyly. Documented inflammation of the digit at birth raises suspicion of neo-adipogenesis, which is recognised in lipomas. This case highlights a rare site for lipoblastomas and explores a potential aetiopathogenesis.     

MIDDLE-FINGER REFLEX

A new reflex is described: middle-finger extensor reflex elicited by percussion of tendon insertion of musculus extensor digitorum communis in forearm. Following percussion using a reflex hammer, two EMG responses from the belly of the muscle were recorded: a short latency monosynaptic reflex with a latency of 31.4 ± 1.5 ms (M1), and a long-latency middle-finger reflex with a mean latency of 64.8 ± 6.31 ms (M2), the former being a monosynaptic extensor reflex, and the latter belonging to a spino-cortico-spinal reflex circuitry. It was suggested that the middle-finger extensor reflex elicited by radial nerve afferents and efferents (C7–C8) would be of clinical and theoretical importance.     

Neural fibrolipoma of a digital nerve of the index finger without macrodactyly

Abstract

We present a case of neural fibrolipoma arising from the digital nerve in the index finger of the right hand. A 31-year-old man was referred with a soft tissue mass in the ulnar aspect of the index finger of his right hand, which had gradually enlarged during the past seven years. Histological examination of an excisional biopsy specimen identified a neural fibrolipoma, which is a differential diagnosis of a lipomatous lesion of the digits.