Martin W. Stenekes

In vivo three-dimensional reconstruction of human median nerves by diffusion tensor imaging.

The in vivo assessment of axonal projections of the peripheral nervous system has been severely limited by the lack of noninvasive techniques. We examined whether MR diffusion tensor imaging with fiber tracking of the human median nerve is feasible. The median nerve was examined with a 3-T MRI scanner in wrists of three healthy volunteers and the wrist of a patient after median nerve repair. In vivo three-dimensional (3D) reconstruction of axonal projections of the median nerve could be achieved in healthy volunteers with intact median nerves and a patient with a transected median nerve using diffusion tensor imaging combined with fiber tracking. The median nerve could be visualized and correlated well to the expected location on T1-weighted images in the patient and all volunteers. The transected median nerve in the patient could be detected up to the site of repair one month postoperatively, whereas the nerve could not be detected more distally immediately after repair. Two months postoperatively, it could clearly be tracked more distally, indicating nerve regeneration. Diffusion tensor imaging can detect the median nerve in healthy individuals as well as up to the lesion site in a patient with a complete transection of the median nerve.

Effects of motor imagery on hand function during immobilization after flexor tendon repair.

OBJECTIVE To determine whether motor imagery during the immobilization period after flexor tendon injury results in a faster recovery of central mechanisms of hand function. DESIGN Randomized controlled trial. SETTING Tertiary referral hospital. PARTICIPANTS Patients (N=28) after surgical flexor tendon repair were assigned to either an intervention group or a control group. INTERVENTION Kinesthetic motor imagery of finger flexion movements during the postoperative dynamic splinting period. MAIN OUTCOME MEASURES The central aspects of hand function were measured with a preparation time test of finger flexion in which subjects pressed buttons as fast as possible following a visual stimulus. Additionally, the following hand function modalities were recorded: Michigan Hand Questionnaire, visual analog scale for hand function, kinematic analysis of drawing, active total motion, and strength. RESULTS After the immobilization period, the motor imagery group demonstrated significantly less increase of preparation time than the control group (P=.024). There was no significant influence of motor imagery on the other tested hand function (P>.05). All tests except kinematic analysis (P=.570) showed a significant improvement across time after the splinting period (P</=.001). CONCLUSIONS Motor imagery significantly improves central aspects of hand function, namely movement preparation time, while other modalities of hand function appear to be unaffected.

Functional dominance of finger flexion over extension, expressed in left parietal activation.

Sensory stimuli may elicit a widely distributed parietal-premotor circuitry underlying task-related movements such as grasping. These stimuli include the visual presentation of an object to be grasped, as well as the observation of grasping performed by others. In this study, we used functional Magnetic Resonance Imaging (fMRI) to test whether the performance of simple finger flexion, contrasted to extension, might similarly activate higher-order circuitry associated with grasping. Statistical Parametric Mapping (SPM) showed that flexion, compared to extension, was related with significant activation of the left posterior parietal cortex and posterior insula, bilaterally. This pattern supported our hypothesis that simple finger flexion has a specific relation with circuitry involved in preparing manual tasks. Although the two motor conditions showed major overlap in the primary motor cortex, increased flexion-related activation at the precentral motor-premotor junction further supported its association with higher-order motor control.

Foreign body reaction triggered by cytotoxic T lymphocyte-associated protein 4 blockade 25 years after dermal filler injection

Foreign body reactions are regularly seen as a late complication of cosmetic treatment with synthetic dermal fillers. Often this foreign body reaction is triggered by a systemic infection, but other systemic triggers are also reported. In this case report, we present a woman in her 60s who was treated with ipilimumab for metastatic melanoma. After two courses of treatment she developed painless facial nodules. A foreign body reaction to dermal fillers was suspected because the patient had received cosmetic treatment with dermal fillers 25 years previously. This reaction was confirmed by excision and histological examination. In the absence of other known triggers, this case revealed immunotherapy (ipilimumab) and subsequent activation of the adaptive immune system as potential triggers of foreign body reactions to dermal fillers. Immunotherapy is increasingly used as anticancer treatment for an increasing number of tumour types. Furthermore, synthetic dermal fillers have frequently been used in the past. Therefore, physicians should be aware of this late‐occurring complication of synthetic filler treatment in patients who develop skin lesions during immunotherapy.

Kinematic analysis of hand movements after tendon repair surgery: a new assessment using drawing movements

Stenekes MW, Nicolai J-PA, Geertzen JHB, Mulder T: Kinematic analysis of hand movements after tendon repair surgery: a new assessment using drawing movements. Am J Phys Med Rehabil 2008;87:169–176. Objective:Although several hand outcome tests exist to judge skill level after hand injury, currently none give insight into how tasks are performed by looking at kinematic parameters. In this article, the clinical value of analyzing kinematic parameters related to the drawing of a triangle on a graphics tablet by healthy subjects and patients with hand injury is discussed. Design:In a first experiment 10 healthy subjects drew the triangles as accurately as possible at various speeds. In a second experiment, 67 healthy subjects and 12 patients with flexor tendon injury were measured repeatedly. Results:In the first experiment, the analysis showed a high linear correlation between speed and accuracy for each individual (Pearson correlation coefficient ≥0.762, P ≤ 0.01). The data led to a formula to standardize deviation for drawing speed, so that different measurements can be compared. In the second experiment, these two measurements correlated well (Pearson correlation coefficient = 0.909, P < 0.001), although a learning effect was noticed (5.4% improvement on average). In healthy subjects the dominant hand performed significantly better than the nondominant hand (P < 0.001). Patients performed significantly worse with their injured hand after 6 wks of dynamic splinting than did healthy subjects (P = 0.003). With their uninjured hand, they performed better than the controls. Six weeks after removal of the splint, no kinematic differences could be discovered between patients and controls. Conclusion:The results show that kinematic parameters of hand movements may be of additional value for assessing functional recovery from hand injury.

Body mass index, chronological age and hormonal status are better predictors of biological skin age than arm skin autofluorescence in healthy women who have never smoked

As life expectancy is increasing and healthy ageing becomes more and more important, skin ageing is a growing topic of interest from both a medical and a commercial point of view. The urgency to unravel the causes of skin ageing is rising. However, there is a lack of objective, simple, noninvasive methods to assess biological skin age – a term introduced to describe how old someone looks, covering both the appearance and function of the skin. A rapid, noninvasive assessment of biological skin age would greatly facilitate the execution of the studies required to find the causes of skin ageing.

Paralytic ectropion treatment with lateral periosteal flap canthoplasty and introduction of the ectropion severity score

Background: Paralytic ectropion patients suffer from impairment of function and appearance of the lower eyelid and are at high risk of developing an exposure keratitis. A canthoplasty procedure can reduce the horizontal eyelid laxity and elevate the lower eyelid. We used a periosteal flap from the outer orbit to create a new canthal ligament. This study investigates the long-term outcomes of this technique. Methods: Cross-sectional outcome study in which 30 cases of paralytic ectropion are treated with a lateral periosteal flap canthoplasty after adequate eyelid shortening. At the desired canthal height, a periosteal flap from the outer temporal orbital rim is mobilized around the rim and sutured in a double-breasted fashion to a tarsal strip. Effect of the operation is measured by comparing preoperative and postoperative photographs for signs of ectropion. For this purpose, a new photograph-based scoring method [the Ectropion Severity Score (ESS)] was developed and evaluated. Results: The ESS proved to be reliable and sensitive to the presence of ectropion. Significant improvement of the ectropion sequelae was measured after a mean follow-up period of 2 years. In 3 cases (13%), a revision procedure was necessary because of relapse of lower eyelid sagging after a mean time of 1.9 years. In these cases, the periosteal flap could be reused. Conclusions: The ESS is a useful instrument to score the severity of paralytic ectropion. The periosteal flap canthoplasty is an effective procedure, with durable results in paralytic ectropion patients. The same periosteal flap can be used in a revision procedure.

Rare causes of closed rupture of the flexor tendon

Abstract Closed injuries to the flexor tendon are relatively rare. We present three rare causes of closed injury to the flexor tendon. Early recognition and adequate treatment by a specialised hand surgeon are crucial for the prognosis of such cases. Delayed diagnosis and treatment often require secondary reconstruction of the flexor tendon, which results in a worse functional outcome.

What to do with non-replanted hands?

We describe a method for the preparation of amputated limbs to obtain a specimen for anatomical study of the arteries and the skeleton. The procedure is particularly applicable to hands, and prevents the destruction of a perfect hand that cannot be replanted.