| 1. |
- Björkman, Anders, et al.
(author)
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Cerebral reorganization in patients with brachial plexus birth injury and residual shoulder problems
- 2016
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In: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 7:DEC
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Journal article (peer-reviewed)abstract
- The functional outcome after a brachial plexus birth injury (BPBI) is based on changes in the peripheral nerve and in the central nervous system. Most patients with a BPBI recover, but residual deficits in shoulder function are not uncommon. The aim of this study was to determine cerebral activation patterns in patients with BPBI and also residual symptoms from the shoulder. In seven patients (six females and one male, aged 17-23 years) with a BPBI and residual shoulder problems (Mallet score IV or lower), the cerebral response to active movement of the shoulder and elbow of the injured and healthy arm was monitored using functional magnetic resonance imaging at 3 T. Movements, i.e., shoulder rotation or elbow flexion and extension, of the injured side resulted in a more pronounced and more extended activation of the contralateral primary sensorimotor cortex compared to the activation seen after moving the healthy shoulder and elbow. In addition, moving the shoulder or elbow on the injured side resulted in increased activation in ipsilateral primary sensorimotor areas an also increased activation in associated sensorimotor areas, in both hemispheres, located further posterior in the parietal lobe, which are known to be important for integration of motor tasks and spatial aspects of motor control. Thus, in this preliminary study based on a small cohort, patients with BPBI and residual shoulder problems show reorganization in sensorimotor areas in both hemispheres of the brain. The increased activation in ipsilateral sensorimotor areas and in areas that deal with both integration of motor tasks and spatial aspects of motor control in both hemispheres indicates altered dynamics between the hemispheres, which may be a cerebral compensation for the injury.
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| 2. |
- Björkman, Anders, et al.
(author)
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Cortical changes in dental technicians exposed to vibrating tools.
- 2010
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In: NeuroReport. - 1473-558X. ; 21, s. 722-726
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Journal article (peer-reviewed)abstract
- To study the cortical reorganization after long time exposure to hand-held vibrating tools, we investigated 10 dental technicians with sensory neuropathy after long time exposure to vibrating tools and 10 controls for cortical changes using functional magnetic resonance imaging at 3 T. The activated volumes corresponding to individual fingers in the hand area of S1 were significantly larger in the neuropathy group than in controls. Activation in the primary motor cortex did not differ significantly from controls. These changes are likely the result of cortical reorganization following long-term non-physiological sensory input and they can partly explain the symptoms seen in vibration-induced neuropathy.
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| 3. |
- Björkman, Anders, et al.
(author)
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Loss of inhibition in ipsilateral somatosensory areas following altered afferent nerve signaling from the hand
- 2018
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In: Neuroscience Research. - : Elsevier BV. - 0168-0102. ; 135, s. 32-36
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Journal article (peer-reviewed)abstract
- Cutaneous stimulation of the hand results in increased neural activity in the contralateral primary somatosensory cortex (S1) in humans, whereas an inhibition of neurons is seen in the ipsilateral S1.The aim of this study was to assess changes in neural activity in the S1 bilaterally, with a focus on the ipsilateral hemisphere, following altered afferent nerve signaling from the hand. Three cohorts, all with altered afferent nerve signaling from the hand, participated in the study. There were: 18 patients with traumatic median nerve injury, 10 patients with vibration induced neuropathy and 11 healthy subjects who had their dominant hand and wrist immobilized for 72 h. In addition, 36 healthy subjects were included as controls. Each subject was examined using functional magnetic resonance imaging at 3 T. All three study cohorts showed enlarged activation in the contralateral S1 during tactile stimulation compared to healthy controls. Moreover, inhibition of the ipsilateral S1 was significantly decreased or completely lost. Thus, somatosensory areas of both hemispheres respond to changed afferent nerve signaling from the hand. The loss of inhibition of neurons in the ipsilateral S1 suggests an important role of the ipsilateral hemisphere in the cerebral adaptation following a change in afferent nerve signaling.
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| 4. |
- Björkman, Anders, et al.
(author)
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Phantom digit somatotopy: a functional magnetic resonance imaging study in forearm amputees.
- 2012
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 36:1, s. 2098-2106
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Journal article (peer-reviewed)abstract
- Forearm amputees often experience non-painful sensations in their phantom when the amputation stump is touched. Cutaneous stimulation of specific stump areas may be perceived as stimulation of specific phantom fingers (stump hand map). The neuronal basis of referred phantom limb sensations is unknown. We used functional magnetic resonance imaging to demonstrate a somatotopic map of the phantom fingers in the hand region of the primary somatosensory cortex after tactile stump stimulation. The location and extent of phantom finger activation in the primary somatosensory cortex corresponded well to the location of normal fingers in a reference population. Stimulation of the stump hand map resulted in an increased bilateral activation of the primary somatosensory cortex compared with stimulation of forearm regions outside the stump hand map. Increased activation was also seen in contralateral posterior parietal cortex and premotor cortex. Ipsilateral primary somatosensory cortex activation might represent a compensatory mechanism and activation of the non-primary fronto-parietal areas might correspond to awareness of the phantom limb, which is enhanced when experiencing the referred sensations. It is concluded that phantom sensation elicited by stimulation of stump hand map areas is associated with activation of finger-specific somatotopical representations in the primary somatosensory cortex. This suggests that the primary somatosensory cortex could be a neural substrate of non-painful phantom sensations. The stump hand map phenomenon might be useful in the development of prosthetic hand devices.
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| 5. |
- Björkman, Anders, et al.
(author)
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Rapid cortical reorganisation and improved sensitivity of the hand following cutaneous anaesthesia of the forearm.
- 2009
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 29:4, s. 837-844
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Journal article (peer-reviewed)abstract
- The cortical representation of various body parts constantly changes based on the pattern of afferent nerve impulses. As peripheral nerve injury results in a cortical and subcortical reorganisation this has been suggested as one explanation for the poor clinical outcome seen after peripheral nerve repair in humans. Cutaneous anaesthesia of the forearm in healthy subjects and in patients with nerve injuries results in rapid improvement of hand sensitivity. The mechanism behind the improvement is probably based on a rapid cortical and subcortical reorganisation. The aim of this work was to study cortical changes following temporary cutaneous forearm anaesthesia. Ten healthy volunteers participated in the study. Twenty grams of a local anaesthetic cream (EMLA) was applied to the volar aspect of the right forearm. Functional magnetic resonance imaging was performed during sensory stimulation of all fingers of the right hand before and during cutaneous forearm anaesthesia. Sensitivity was also clinically assessed before and during forearm anaesthesia. A group analysis of functional magnetic resonance image data showed that, during anaesthesia, the hand area in the contralateral primary somatosensory cortex expanded cranially over the anaesthetised forearm area. Clinically right hand sensitivity in the volunteers improved during forearm anaesthesia. No significant changes were seen in the left hand. The clinically improved hand sensitivity following forearm anaesthesia is probably based on a rapid expansion of the hand area in the primary somatosensory cortex which presumably results in more nerve cells being made available for the hand in the primary somatosensory cortex.
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| 6. |
- Chemnitz, Anette, et al.
(author)
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Normalized activation in the somatosensory cortex 30 years following nerve repair in children- an fMRI study.
- 2015
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 42:4, s. 2022-2027
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Journal article (peer-reviewed)abstract
- The clinical outcome following a peripheral nerve injury in the upper extremity is generally better in young children than in teenagers and in adults, but the mechanism behind this difference is unknown. In twenty-eight patients with a complete median nerve injury sustained at the ages of 1-13 years (n=13) and 14-20 years (n=15), the cortical activation during tactile finger stimulation of the injured and healthy hands was monitored at a median time since injury of 28 years using functional magnetic resonance imaging (fMRI) at 3 Tesla. The results from the fMRI were compared with the clinical outcome and electroneurography. The cortical activation pattern following sensory stimulation of the median nerve innervated fingers was dependent on the patient's age at injury. Those injured at a young age (1-13 years) had an activation pattern similar to that of healthy controls. Furthermore, they showed a clinical outcome significantly superior (p=0.001) to the outcome in subjects injured at a later age, however, electroneurographical parameters did not differ between the groups. In subjects injured at age 14-20 years, a more extended activation of the contralateral hemisphere was seen in general. Interestingly, these patients also displayed changes in the ipsilateral hemisphere where a reduced inhibition of somatosensory areas was seen. This loss of ipsilateral inhibition correlated to increasing age at injury as well as to poor recovery of sensory functions in the hand. In conclusion, cerebral changes in both brain hemispheres may explain differences in clinical outcome following a median nerve injury in childhood or adolescence. This article is protected by copyright. All rights reserved.
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| 7. |
- Entrop, Joshua P., et al.
(author)
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Reproduction patterns among classical Hodgkin lymphoma survivors treated with BEACOPP and ABVD in Sweden, Denmark and Norway-A population-based matched cohort study
- 2023
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In: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 153:4, s. 723-731
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Journal article (peer-reviewed)abstract
- Childbirth rates in classical Hodgkin lymphoma (cHL) survivors have historically been reduced compared to the general population. Understanding if contemporary treatment protocols are associated with reduced fertility is crucial as treatment guidelines shift toward more liberal use of intensive chemotherapy. We identified 2834 individuals aged 18-40 years with cHL in Swedish and Danish lymphoma registers, and in the clinical database at Oslo University Hospital diagnosed 1995-2018, who were linked to national medical birth registers. Cox regression adjusted for stage, performance status, year, and age at diagnosis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) contrasting time to first childbirth by treatment groups (ABVD, 2-4 BEACOPP, 6-8 BEACOPP) up to 10 years after diagnosis. Overall, 74.8% of patients were treated with ABVD, 3.1% with 2-4 BEACOPP and 11.2% with 6-8 BEACOPP. Adjusted HRs comparing childbirth rates in individuals treated with 6-8 BEACOPP, and 2-4 BEACOPP to ABVD were 0.53 (CI: 0.36-0.77) and 0.33 (CI: 0.12-0.91) for males, and 0.91 (CI: 0.61-1.34) and 0.38 (CI: 0.12-1.21) for females. Cumulative incidence of childbirths after 10 years was 19.8% (CI: 14.5%-27.0%) for males and 34.3% (CI: 25.8%-45.6%) for females treated with 6-8 BEACOPP. Proportions of children born after assisted reproductive technique (ART) treatments were 77.4% (CI: 60.2-88.6%) for males following 6-8 BEACOPP, and <11% for females. Among ABVD treated patients the corresponding proportions were 12.2% (CI: 8.5%-17.3%) and 10.6% (CI: 7.4%-14.9%). BEACOPP treatment is associated with decreased childbirth rates compared to ABVD in male, but not female, cHL patients, despite widespread access to ART in the Nordics.
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| 8. |
- Entrop, Joshua P., et al.
(author)
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Reproduction patterns among non-Hodgkin lymphoma survivors by subtype in Sweden, Denmark and Norway : A population-based matched cohort study
- 2023
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In: British Journal of Haematology. - : John Wiley & Sons. - 0007-1048 .- 1365-2141. ; 202:4, s. 785-795
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Journal article (peer-reviewed)abstract
- Previous studies concerning reproductive patterns among non-Hodgkin lymphoma (NHL) survivors are scarce and those available have reported conflicting results. Treatment regimens vary considerably between aggressive and indolent NHL and studies of reproductive patterns by subtypes are warranted. In this matched cohort study, we identified all NHL patients aged 18-40 years and diagnosed between 2000 and 2018 from the Swedish and Danish lymphoma registers, and the clinical database at Oslo University Hospital (n = 2090). Population comparators were matched on sex, birth year and country (n = 19 427). Hazard ratios (HRs) were estimated using Cox regression. Males and females diagnosed with aggressive lymphoma subtypes had lower childbirth rates (HRfemale: 0.43, 95% CI: 0.31-0.59, HRmale: 0.61, 95% CI: 0.47-0.78) than comparators during the first 3 years after diagnosis. For indolent lymphomas, childbirth rates were not significantly different from comparators (HRfemale: 0.71, 95% CI: 0.48-1.04, HRmale: 0.94, 95% CI: 0.70-1.27) during the same period. Childbirth rates reached those of comparators for all subtypes after 3 years but the cumulative incidence of childbirths was decreased throughout the 10-year follow-up for aggressive NHL. Children of NHL patients were more likely to be born following assisted reproductive technology than those of comparators, except for male indolent lymphoma patients. In conclusion, fertility counselling is particularly important for patients with aggressive NHL.
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| 9. |
- Johansson, Karin, et al.
(author)
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A Home-Based Weight Lifting Program for Patients with Arm Lymphedema Following Breast Cancer Treatment: A Pilot and Feasibility Study
- 2014
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In: Lymphology. - 0024-7766. ; 47:2, s. 51-64
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Journal article (peer-reviewed)abstract
- It is well documented that resistance exercise can be performed by patients with breast cancer-related arm lymphedema. The aim of this pilot study was to evaluate the feasibility and safety of a 12-week self-administered weight lifting program for arm and shoulder, and its influence on arm lymphedema status, upper extremity muscle strength, and disability. Twenty-three patients with breast cancer-related arm lymphedema performed the program 3 times/week. The weight resistance levels were individually adjusted for shoulder flexion and adduction, and elbow extension and flexion corresponding to a repetition range of 8-12 repetition maximum. A log book was used to evaluate adherence to the program, wearing of compression sleeve and perceived exertion. Measurements were performed before a 2-week control period without intervention, and before and after intervention, and with arm volume measurements every fortnight to check for adverse events. Results revealed no significant changes during the control period. Adherence to the intervention program was excellent, and two adverse events were registered during the first weeks. After intervention, an increase of shoulder and arm strength (measured by an isometric muscle strength device) was found in all exercises (p=0.001-0.003). A reduction of excess volume was shown, in ml (p=0.03) and percentage (p=0.005), measured by water displacement method. A tendency towards reduction (p=0.07) of fat tissue in the upper arm (n=10) in both arms was found measured by MRI. In this pilot study, we concluded that a home-based weight-lifting program performed by patients with breast cancer-related arm lymphedema is feasible and safe providing that the program includes regular follow-up for safety.
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| 10. |
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