Experiences of combined visual training and arm activation in the rehabilitation of unilateral visual neglect: A clinical study

This study reports a rehabilitation training for unilateral visual neglect combining a visual training programme and arm activation. Four cases of left visual neglect are presented with differing arm use. Neglect impairment was assessed using seven neuropsychological tests at weekly intervals for nine weeks: three weeks before, during and after the treatment period. In addition, one patient was followed over a longer time period. The treatment consisted of both a visual training programme and simultaneous arm activation. Considerable improvement in three of the four patients was observed in article reading. Moreover, all patients showed some improvement on three cancellation tests, whereas there was no improvement on other tests. In particular, the patients who had full hand or shoulder movement showed improvement in their performance. These results point out the usefulness of combined visual training and arm activation in the rehabilitation of visual neglect.     

Physical exercise increases adult hippocampal neurogenesis in male rats provided it is aerobic and sustained

Key points

• Aerobic exercise, such as running, enhances adult hippocampal neurogenesis (AHN) in rodents.
• Little is known about the effects of high‐intensity interval training (HIT) or of purely anaerobic resistance training on AHN.
• Here, compared with a sedentary lifestyle, we report a very modest effect of HIT and no effect of resistance training on AHN in adult male rats.
• We found the most AHN in rats that were selectively bred for an innately high response to aerobic exercise that also run voluntarily and increase maximal running capacity.
• Our results confirm that sustained aerobic exercise is key in improving AHN.

Abstract

Aerobic exercise, such as running, has positive effects on brain structure and function, such as adult hippocampal neurogenesis (AHN) and learning. Whether high‐intensity interval training (HIT), referring to alternating short bouts of very intense anaerobic exercise with recovery periods, or anaerobic resistance training (RT) has similar effects on AHN is unclear. In addition, individual genetic variation in the overall response to physical exercise is likely to play a part in the effects of exercise on AHN but is less well studied. Recently, we developed polygenic rat models that gain differentially for running capacity in response to aerobic treadmill training. Here, we subjected these low‐response trainer (LRT) and high‐response trainer (HRT) adult male rats to various forms of physical exercise for 6–8 weeks and examined the effects on AHN. Compared with sedentary animals, the highest number of doublecortin‐positive hippocampal cells was observed in HRT rats that ran voluntarily on a running wheel, whereas HIT on the treadmill had a smaller, statistically non‐significant effect on AHN. Adult hippocampal neurogenesis was elevated in both LRT and HRT rats that underwent endurance training on a treadmill compared with those that performed RT by climbing a vertical ladder with weights, despite their significant gain in strength. Furthermore, RT had no effect on proliferation (Ki67), maturation (doublecortin) or survival (bromodeoxyuridine) of new adult‐born hippocampal neurons in adult male Sprague–Dawley rats. Our results suggest that physical exercise promotes AHN most effectively if the exercise is aerobic and sustained, especially when accompanied by a heightened genetic predisposition for response to physical exercise.

Abbreviations

AHN

adult hippocampal neurogenesis

BDNF

brain‐derived neurotrophic factor

BrdU

bromodeoxyuridine

HIT

high‐intensity interval training

HRT

high‐response trainer

LRT

low‐response trainer

RW

running wheel

Sed

sedentary

TBS

Tris‐buffered saline

V˙O2max

maximal oxygen uptake

     

Effects of tissue-engineered articular disc implants on the biomechanical loading of the human temporomandibular joint in a three-dimensional finite element model

The purpose of this study was to evaluate biomechanical loading of the temporomandibular joint when using a biodegradable laminate implant to replace the articular disc and to test the hypothesis that the use of the implant reduces stress distribution in the condyle, implant, and glenoid fossa. A finite element model of a female human mandible, including the temporomandibular joint, which had two standard endosseous implants inserted bilaterally in the premolar region, was constructed from computed tomography scan images using a commercially available finite element software. The disc, condyle, and glenoid fossa were arbitrarily divided into five regions: the anterior, posterior, medial, lateral, and central. The disc was then replaced with a poly-L/DL-lactide biodegradable laminate. The finite element model was then used to predict principal and Von Mises stresses. The use of poly-L/DL-lactide implant resulted in remarkable reduction in Von Mises stresses (approximately threefold) in the anterior, central, and medial regions of the mandibular condyle in comparison with slight to moderate stress reductions in the corresponding regions of the implant and glenoid fossa. The mandibular condyle also demonstrated the largest total displacement in all directions followed by the implant and glenoid fossa. The use of an alloplastic implant such as the bioresorbable, poly-L/DL-lactide laminate to replace the articular disc reduces loading of the mandibular condyle rather than the implant and glenoid fossa. These findings lead to support the hypothesis that the mandibular condyle more likely functions as a shock absorber than the disc. The use of bioresorbable laminate implants might prove an efficient technique to replace the articular disc and promote normal function of the temporomandibular joint.     

Dual contrast in computed tomography allows earlier characterization of articular cartilage over single contrast

Cationic computed tomography contrast agents are more sensitive for detecting cartilage degeneration than anionic or non-ionic agents. However, osteoarthritis-related loss of proteoglycans and increase in water content contrarily affect the diffusion of cationic contrast agents, limiting their sensitivity. The quantitative dual-energy computed tomography technique allows the simultaneous determination of the partitions of iodine-based cationic (CA4+) and gadolinium-based non-ionic (gadoteridol) agents in cartilage at diffusion equilibrium. Normalizing the cationic agent partition at diffusion equilibrium with that of the non-ionic agent improves diagnostic sensitivity. We hypothesize that this sensitivity improvement is also prominent during early diffusion time points and that the technique is applicable during contrast agent diffusion. To investigate the validity of this hypothesis, osteochondral plugs (d = 8 mm, N = 33), extracted from human cadaver (n = 4) knee joints, were immersed in a contrast agent bath (a mixture of CA4+ and gadoteridol) and imaged using the technique at multiple time points until diffusion equilibrium. Biomechanical testing and histological analysis were conducted for reference. Quantitative dual-energy computed tomography technique enabled earlier determination of cartilage proteoglycan content over single contrast. The correlation coefficient between human articular cartilage proteoglycan content and CA4+ partition increased with the contrast agent diffusion time. Gadoteridol normalized CA4+ partition correlated significantly (P < .05) with Mankin score at all time points and with proteoglycan content after 4 hours. The technique is applicable during diffusion, and normalization with gadoteridol partition improves the sensitivity of the CA4+ contrast agent.     

Clinical value of ultrasound in the evaluation of dyspepsia in primary health care

OBJECTIVE: In general practice, upper abdominal ultrasound (US) is widely used in the evaluation of patients with dyspepsia. However, there is a dearth of published data on the role of US in the dyspepsia work-up. There are no data on the use of US as a follow-up study in functional dyspepsia. The aims of this study were to assess the role of US in evaluating dyspepsia, and to assess the long-term clinical relevance of minor findings revealed by US in patients with functional dyspepsia. MATERIAL AND METHODS: Four hundred consecutive dyspeptic patients were recruited. At baseline, all patients underwent gastroscopy and US. Patients were divided into two groups: "endoscopy-negative patients" and "endoscopy-positive patients". "The endoscopy-negative" group included all cases in which the final diagnoses could not be settled after gastroscopy. US was repeated after 6-7 years in patients who had functional dyspepsia. RESULTS: In the endoscopy-negative group, gallstones were detected in 21 patients, but this was considered to be a cause of symptoms in 9 patients. No malignant lesions were detected by US in the endoscopy-negative group. In the endoscopy-positive group, a malignant tumor in the kidney was suspected in 3 patients. Only one of these tumors turned out to be an incidental small carcinoma. Moreover, several minor findings were shown by US: usually these consisted of abnormal echogenicity of the liver. During the follow-up period, 6 patients developed gallstones. At the end of the follow-up period, two clinically significant findings were diagnosed: a small renal cancer and hydronephrosis. CONCLUSIONS: This study shows that the wide, untargeted use of abdominal US in the evaluation of patients with dyspepsia following a gastroscopy is not necessary. Repeated US examination in cases of functional dyspepsia is not recommended, and rarely changes the diagnosis.