Search

Carpal tunnel syndrome (CTS) is a common peripheral nerve disease in adults; it can cause pain, numbness, and even muscle atrophy and will adversely affect patients' daily life and work. There are no standard diagnostic criteria that go against the early diagnosis and treatment of patients. MRI as a novel imaging technique can show the patient's condition more objectively, and several characteristics of carpal tunnel syndrome have been found. However, various image sequences, heavy artifacts, small lesion characteristics, high volume of imagine reading, and high difficulty in MRI interpretation limit its application in clinical practice. With the development of automatic image segmentation technology, the algorithm has great potential in medical imaging. The challenge is that the segmentation target is too small, and there are two categories of images with the proximal border of the carpal tunnel as the boundary. To meet the challenge, we propose an end-to-end deep learning framework called Deep CTS to segment the carpal tunnel from the MR image. The Deep CTS consists of the shape classifier with a simple convolutional neural network and the carpal tunnel region segmentation with simplified U-Net. With the specialized structure for the carpal tunnel, Deep CTS can segment the carpal tunnel region efficiently and improve the intersection over union of results. The experimental results demonstrated that the performance of the proposed deep learning framework is better than other segmentation networks for small objects. We trained the model with 333 images, tested it with 82 images, and achieved 0.63 accuracy of intersection over union and 0.17 s segmentation efficiency, which indicate great promise for the clinical application of this algorithm., (© 2022. The Author(s) under exclusive licence to Society for Imaging Informatics in Medicine.)

Ultrasound (US) imaging is recognized as a useful support for Carpal Tunnel Syndrome (CTS) assessment through the evaluation of median nerve morphology. However, US is still far to be systematically adopted to evaluate this common entrapment neuropathy, due to US intrinsic challenges, such as its operator dependency and the lack of standard protocols. To support sonographers, the present study proposes a fully-automatic deep learning approach to median nerve segmentation from US images. We collected and annotated a dataset of 246 images acquired in clinical practice involving 103 rheumatic patients, regardless of anatomical variants (bifid nerve, closed vessels). We developed a Mask R-CNN with two additional transposed layers at segmentation head to accurately segment the median nerve directly on transverse US images. We calculated the cross-sectional area (CSA) of the predicted median nerve. Proposed model achieved good performances both in median nerve detection and segmentation: Precision (Prec), Recall (Rec), Mean Average Precision (mAP) and Dice Similarity Coefficient (DSC) values are 0.916 ± 0.245, 0.938 ± 0.233, 0.936 ± 0.235 and 0.868 ± 0.201, respectively. The CSA values measured on true positive predictions were comparable with the sonographer manual measurements with a mean absolute error (MAE) of 0.918 mm 2 . Experimental results showed the potential of proposed model, which identified and segmented the median nerve section in normal anatomy images, while still struggling when dealing with infrequent anatomical variants. Future research will expand the dataset including a wider spectrum of normal anatomy and pathology to support sonographers in daily practice., (© 2022. The Author(s).)

Carpal tunnel syndrome (CTS) may be caused by subclinical tenosynovitis which may be detected by ultrasonography (US). The objective of this study is to investigate whether ultrasonography has a place in the workup of idiopathic CTS patients. Therefore, we investigated the prevalence of tenosynovitis and its association with the clinical outcome of surgery. A cohort of 31 consecutive idiopathic CTS patients (33 wrists) who were a candidate for carpal tunnel release (CTR) surgery was assessed using greyscale ultrasonography (GSUS) and power Doppler ultrasonography (PDUS). Peroperatively, tenosynovitis was evaluated macroscopically by the surgeon. Tissue samples from areas macroscopically suspected for tenosynovitis were taken for histological evaluation. The clinical outcome of the operation was assessed after 6 months and if applicable alternative diagnoses for the CTS were proposed. US tenosynovitis (OMERACT) was detected preoperatively in 58 % of the wrists. Peroperatively, macroscopic tenosynovitis was detected visually in 88 % of the wrists. Histological evaluation demonstrated a limited influx of lymphocytes indicative of a mild chronic inflammatory response in 19 %. Non-specific reactive changes were observed in 78 % of the cases. Ultrasonographically defined tenosynovitis was associated with an OR of 2.81 (95 % CI 0.61-13) for responding well to surgery. Most cases of ultrasonographic and peroperatively defined tenosynovitis were classified by histology as reactive changes. The presence of ultrasonographic tenosynovitis might be associated with a better clinical outcome of surgery.

Objective: To identify palmar cutaneous branches of median nerve and ulnar nerve (PCBMN and PCBUN) and try to find a safe path at wrist and forearm in the decompression procedure of carpal tunnel syndrome., Materials and Methods: Ten formalin-fixed and five fresh-frozen cadaveric forearms were included in the study. The cross point of longitude of middle finger and distal wrist crease was defined as 0 point. Distal wrist crease (DWC) and 0 point were chosen as references for measurements. Several points on the pathway of PCBMN and PCBUN were measured., Results: The average distance between the origin of the PCBMN and PCBUN to the DWC was 4.95 ± 0.88 cm, 10.12 ± 1.50 cm, separately. The average distance between DWC and the point where PCBMN and PCBUN separated from their trunk was found to be 2.09 ± 0.31 cm, 2.90 ± 0.50 cm, separately. The distances between PCBMN, PCBUN and 0 point at DWC level was found to be 0.61 ± 0.12 cm, 0.47 ± 0.31 cm, separately. The diameters of two cutaneous branches were 0.10 ± 0.02 cm, 0.11 ± 0.04 cm, separately., Conclusion: The general longitudinal palmar incision could avoid injuries to recurrent branch of median nerve and distal branches of palmar cutaneous nerve can be avoided macroscopically. The area about 5 mm ulnar and 6 mm radial to 0 point at wrist level was a relatively safe area.

Over the last few years remarkable efforts have been made using functional imaging studies to unravel brain processing of pain and decipher underlying neuronal mechanisms. Cerebral processing in experimental pain models, especially those provoking hyperalgesia, and its pharmacological modulation will form the first part of this review. In a second part we will address central mechanisms of clinical neuropathic pain. Up to now, there are at least six main mechanisms involved in the chronification of neuropathic pain: (i) activity increase in areas of the pain neuromatrix, (ii) recruitment of additional cortical areas beyond the classical pain neuromatrix, (iii) cortical reorganization and maladaptive neuroplasticity, (iv) alterations in neurochemistry (v) structural brain changes and (vi) disruption of the brain default mode network. In a third part of this review we discuss mechanisms of endogenous pain modulation.

Background: Borrelia lusitaniae was isolated from an Ixodes ricinus tick in Portugal in 1993 for the first time. Further, this borrelia genospecies has been found in ixodid ticks collected around the coasts of southern Portugal and North Africa. Its reservoir has not been defined yet. B. lusitaniae was isolated once until now from a patient with a long standing and expanding skin disorder., Patient and Methods: A 46-year-old Portuguese woman presented with a skin lesion on the left thigh which had evolved slowly over ten years. The patient reported limb paraesthesias, cramps, chronic headaches, and cardiac rhythm disturbances. History of tick bites was negative nor had the patient ever noticed a skin lesion comparable with erythema chronicum migrans. Skin biopsies were taken for histological evaluation, culture and DNA detection. Antibodies to borrelia were searched by indirect immunofluorescence assay and Western-blot., Results: A bilateral carpal tunnel syndrome and local synovitis was diagnosed. Dermato-histology was normal, serology was negative. Spirochaetal organisms were cultured from a skin biopsy and identified as B. lusitaniae. The patient improved after a 2-week course of intravenous ceftriaxone; the skin lesions did not expand further., Conclusions: This culture confirmed skin infection by B. lusitaniae in a patient from Portugal suggests an additional human pathogen out of the B. burgdorferi sensu lato complex in Europe, particularly in Portugal.

Silicone synovitis is an important clinical entity recognized in rheumatoid patients after arthroplasties with silicone implants. It is a foreign body reaction to particulate material (silicone elastomer) characterized clinically by the re-occurrence of pain, stiffness and swelling at the site of arthroplasty after initial relief of symptoms. Whereas silicone synovitis is a rare complication in metacarpophalangeal implants, it is an important one in the wrist implant. Long-term follow-up studies have revealed that the rates of fracture and subsidence are high and that the implants deteriorate with time necessitating operative revisions in up to 50% of cases. Indications should therefore be restricted to a painful wrist in the elderly, very low demand patient with insufficient bone stock to permit total wrist arthroplasty with a metal-on-plastic design. Severe preoperative deformity and the need for use of ambulatory aids may further limit the indication. The unusual case of direct perforation of silicone particles from the wrist into the tendon sheath of the M. flexor pollicis longus inducing a tumor-like synovitis and a secondary carpal tunnel syndrome is presented. The importance of silicone synovitis and the indication at present for implantation of a silicone wrist spacer in the rheumatoid patient are discussed.

Background: beta2-microglobulin (beta2m) is considered to be the amyloidogenic precursor in dialysis-related amyloidosis (DRA, Abeta2M amyloidosis). beta2m modified with advanced glycation end products (AGE) may be an important factor in the pathogenesis of DRA. The presence of AGE in beta2m-positive amyloid deposits and surrounding macrophages has been demonstrated by immunohistochemical techniques in light microscopy., Methods: In order to better define the localization of beta2m and AGE in amyloid deposits and in cells, carpal tunnel connective tissues obtained from surgical specimens in six patients with DRA were studied by immunohistochemistry and electron microscopy, using the avidine-biotine complex and immunogold staining procedures, respectively. A polyclonal rabbit anti-human beta2m and two monoclonal mouse anti-AGE antibodies [AG-1 anti-imidazolone and AG-10 anti-N(epsilon)-carboxymethyl-lysine] enabled us to label their respective antigens at the optical and ultrastructural level., Results: with both techniques, extracellular amyloid deposits strongly reacted with anti-beta2m and anti-AGE antibodies, although the immunoreactivity of beta2m was more intense. Macrophage-like synovial cells (CD-68 positive) surrounding amyloid deposits were also immunoreactive for beta2m and AGE, which were detected in lysosomes and in intracellular fibrillar material. Anti-AGE reactivity was also evident in collagenous structures in the absence of beta2m or amyloid deposits, supporting the proposal that AGE modification of collagen might have pathogenic relevance in the development of DRA., Conclusions: The co-localization of AGE and beta2m, both intra- and extra-cellularly, in amyloid fibrils was confirmed by immunoelectron microscopy; however, the positivity of collagen to anti-AGE antibodies and a different pattern of intracellular localization suggest that molecules other than beta2m may also be modified by AGE and may be involved in the pathogenesis of DRA.

Osteopoikilosis (Osteopathia condensans disseminata) is a rare and usually asymptomatic sclerosing bone dysplasia of unknown origin. Familial clustering suggests a dominant inheritance. The observation of a 47-year-old woman lead to differential diagnostic considerations in view of the literature on about 350 cases. For 2 years the patient has been complaining about pain and stiffness of both hands with swelling of the fingers. Additionally, she remarked about bilateral paresthesias corresponding to the sensory innervation of the median nerve. Clinical examination revealed a sensory carpal tunnel syndrome and mild synovitis of the proximal interphalangeal joints with skin induration and limited flexion of the fingers. In addition, some finger and toe nails showed pitting and most fingers had scar-like linear skin alterations. Radiologic findings showed symmetric, well-defined, homogeneous sclerosing areas in spongy bone. The combination of symmetrical sclerosing bone densities, hereditary character, and associated skin and joint manifestations suggests the existence of a general connective tissue disease.

The median nerve divides into its terminal branches at or proximal to the distal edge of the flexor retinaculum. An anatomy of the median nerve within the carpal tunnel is reported in two separate cases. Emphasis has been given to the value of direct vision when incising the flexor retinaculum in order to avoid injure of the median nerve.

A total of 18 hemodialyzed patients submitted to surgery for the treatment of carpal tunnel syndrome are examined. In all of the cases pre- and postoperative EMG and biopsy were performed. Six months after surgery all of the patients showed improved pain symptoms, in 66% there was good recovery of sensitivity and of the function of the hand: these results were confirmed by EMG monitoring. In all of the biopsies amyloid deposits, particularly diffused in the tendinous and nervous sheaths, were observed. At 2-year follow-up 75% of the patients showed recurrence of pain symptoms. Thus, surgery does not seem to definitively resolve symptoms.

In order to create an experimental model for the carpal tunnel syndrome without the use of the commonly applied foreign bodies (silicone or rubber tubes, tourniquets etc.), the present study tried to induce a chemically provoked compression of the median nerve in rabbits. In 9 female rabbits 1 ml of Aethoxskerol 3% (Hydrox-polyethoxy dodecan) was instilled into the carpal tunnel around the median nerve after visualisation of the nerve. The other foreleg served as the control and was treated with the same amount of saline solution. Electroneurophysiologic parameters were registered preoperatively, 1 month and 6 months post surgery and histomorphologic investigations by light and electron microscopy were performed after 6 months. 6 months after treatment with Aethoxysklerol, a statistically significant lengthening of the distal latency period as well as a significant reduction of the compound potential amplitude could be observed. In accordance with these findings, morphological investigation revealed the presence of extensive granulation tissue around the median nerve together with signs of demyelination. Our results indicate that we were able to produce the development of extensive granulation tissue in the carpal tunnel of rabbits with subsequent compression of the median nerve which was confirmed by histomorphologic investigation as well as by measurement of nerve conductive velocity.

beta 2-microglobulin amyloidosis is a major complication in chronic hemodialysis patients. Destructive arthropathy, spondylarthropathy, and carpal tunnel syndrome are clinical manifestations of beta 2M amyloid depositions within the joints, intervertebral discs, and tendon sheets. We have investigated the prevalence of beta 2M amyloidosis associated radiological joint lesions in a population of 175 patients on chronic hemodialysis. In 32 of 175 patients the diagnosis of amyloidosis arthropathy and spondylarthropathy was made by radiomorphological criteria. These 32 patients were asked about rheumatic symptoms (localisation and character of pain, synovitis, carpal tunnel syndrome, influence of dialysis membrane on pain) and examined clinically. Bilateral pain of the shoulders or wrists was complained by most of the patients. 24 of the 32 patients had signs of secondary hyperparathyroidism besides beta 2M-amyloidosis. 29 patients had a carpal tunnel syndrome, 23 of whom had to be operated. beta 2M-amyloid was histochemically demonstrated in all of these 23 cases. Renal transplantation led to immediate pain relief in 3 out of 3 patients, a change of the dialysis membrane (high-flux membrane) improved chronic pain in the majority of patients.

The aetiology of carpal tunnel syndrome in about 50% of patients is not clear. These patients are frequently older woman. Measurements of the carpal tunnel cross-sectional area in eleven female patients revealed a narrow carpal tunnel as compared with female or male controls. Primary carpal tunnel stenosis as a cause of entrapment of the median nerve is postulated.