0000000001285787
AUTHOR
Ina M. Tarkka
Effects of exercise and diet interventions on obesity-related sleep disorders in men: study protocol for a randomized controlled trial.
Abstract Background Sleep is essential for normal and healthy living. Lack of good quality sleep affects physical, mental and emotional functions. Currently, the treatments of obesity-related sleep disorders focus more on suppressing sleep-related symptoms pharmaceutically and are often accompanied by side effects. Thus, there is urgent need for alternative ways to combat chronic sleep disorders. This study will investigate underlying mechanisms of the effects of exercise and diet intervention on obesity-related sleep disorders, the role of gut microbiota in relation to poor quality of sleep and day-time sleepiness, as well as the levels of hormones responsible for sleep-wake cycle regulati…
European core curriculum in neurorehabilitation.
Item does not contain fulltext To date, medical education lacks Europe-wide standards on neurorehabilitation. To address this, the European Federation of NeuroRehabilitation Societies (EFNR) here proposes a postgraduate neurorehabilitation training scheme. In particular, the European medical core curriculum in neurorehabilitation should include a two-year residency in a neurorehabilitation setting where trainees can gain practical experience. Furthermore, it should comprise six modules of classroom training organized as weekend seminars or summer/winter schools. In conclusion, after defining the European medical core curriculum in neurorehabilitation, the next activities of the EFNR will be…
Long-Term Physical Activity May Modify Brain Structure and Function: Studies in Young Healthy Twins
Background: Physical activity (PA) is said to be beneficial to many bodily functions. However, the effects of PA in the brain are still inadequately known. The authors aimed to uncover possible brain modulation linked with PA. Here, they combine 4 of their studies with monozygotic twins, who were within-pair discordant in PA for a minimum of 1 year. Methods: The authors performed brain imaging, brain electrophysiology, and cardiovascular and body composition assessments, and collected questionnaire-based data. The present synopsis elucidates the differences associated with differing PA history in conditions without genetic variability. They present new structural and electrophysiological re…
Older Age Increases the Amplitude of Muscle Stretch-Induced Cortical Beta-Band Suppression But Does not Affect Rebound Strength
Healthy aging is associated with deterioration of the sensorimotor system, which impairs balance and somatosensation. However, the exact age-related changes in the cortical processing of sensorimotor integration are unclear. This study investigated primary sensorimotor cortex (SM1) oscillations in the 15–30 Hz beta band at rest and following (involuntary) rapid stretches to the triceps surae muscles (i.e., proprioceptive stimulation) of young and older adults. A custom-built, magnetoencephalography (MEG)-compatible device was used to deliver rapid (190°·s−1) ankle rotations as subjects sat passively in a magnetically-shielded room while MEG recorded their cortical signals. Eleven young (age…
Visual processing in patients with age-related macular degeneration performing a face detection test
Purpose: People with age-related macular degeneration (AMD) have difficulties in familiar face recognition and facial expression discrimination. Our aim was to evaluate the visual processing of faces in AMD patients and whether this would be improved by anti-vascular endothelial growth factor therapy. This was a prospective interventional cohort study. Patients: Twelve patients with monocular wet AMD and 6 control subjects were recruited. Face detection processes were studied using cortical event-related potentials (ERPs). Patients received 3 bevacizumab intravitreal injections to the single affected eye. At baseline and 4–6 weeks after the last injection, clinical presentation and ERPs of …
Physical activity does not inevitably improve quality of life in young adults with type 1 diabetes
Relationships between exercise, glucose control and diabetes dependent quality of life (DDQoL) are not straightforward. We investigated the DDQoL of 99 persons with type 1 diabetes and linked it to individual amount of weekly physical activity and HbA1c. Physically active lifestyle was not associated with better DDQoL or glucose control.
Functional MRI and motor behavioral changes obtained with constraint-induced movement therapy in chronic stroke
Background: The clinical benefits of intensive stroke rehabilitation vary individually. We used multimodal functional imaging to assess the relationship of clinical gain and imaging changes in patients with chronic stroke whose voluntary motor control improved after constraint-induced movement therapy (CIMT). Methods: Eleven patients (37.6 ± 36.8 months from stroke) were studied by functional MRI (fMRI), transcranial magnetic stimulation (TMS), and behavioral assessment of hand motor control (Wolf Motor Function Test) before and after 2 weeks of CIMT. Individual and group-level changes in imaging and behavioral parameters were investigated. Results: Increase in fMRI activation in the sen…
Gait Impairment in a Rat Model of Focal Cerebral Ischemia
The availability of proper tests for gait evaluation following cerebral ischemia in rats has been limited. The automated, quantitative CatWalk system, which was initially designed to measure gait in models of spinal cord injury, neuropathic pain, and peripheral nerve injury, is said to be a useful tool for the study of motor impairment in stroke animals. Here we report our experiences of using CatWalk XT with rats subjected to transient middle cerebral artery occlusion (MCAO), during their six-week followup. Large corticostriatal infarct was confirmed by MRI in all MCAO rats, which was associated with severe sensorimotor impairment. In contrast, the gait impairment was at most mild, which i…
Cardiorespiratory Fitness, Physical Activity, and Insulin Resistance in Children
Purpose Few studies have investigated the independent and joint associations of cardiorespiratory fitness (CRF) and body fat percentage (BF%) with insulin resistance in children. We investigated the independent and combined associations of CRF and BF% with fasting glycemia and insulin resistance and their interactions with physical activity (PA) and sedentary time among 452 children age 6 to 8 yr. Methods We assessed CRF with a maximal cycle ergometer exercise test and used allometrically scaled maximal power output (Wmax) for lean body mass (LM) and body mass (BM) as measures of CRF. The BF% and LM were measured by dual-energy X-ray absorptiometry, fasting glycemia by fasting plasma glucos…
Effects of intensive therapy using gait trainer or floor walking exercises early after stroke.
Objective: To analyse the effects of gait therapy for patients after acute stroke in a randomized controlled trial. Methods: Fifty-six patients with a mean of 8 days post-stroke participated in: (i) gait trainer exercise; (ii) walking training over ground; or (iii) conventional treatment. Patients in the gait trainer exercise and walking groups practiced gait for 15 sessions over 3 weeks and received additional physiotherapy. Functional Ambulatory Category and several secondary outcome measures assessing gait and mobility were administered before and after rehabilitation and at 6-month follow-up. Patients also evaluated their own effort. Results: Walking ability improved more with intensive…
Ten-year resistance training background modulates somatosensory P3 cognitive brain resonse in older men : a magnetoencephalograpy study
The brain electrophysiological component P3, associated with good cognitive abilities, deteriorates during healthy aging. Both cognitive functions and P3 component amplitude respond positively to exercise, but the effects of resistance training on P3 are much less studied. Short-term resistance training interventions in older adults indicate modulation towards larger P3 amplitude, but this association has not been studied with a longitudinal study design. We investigated magnetoencephalographically recorded P3 (P3m) in a unique study design of nine aged men (mean age 77.7 y) with quasi-supervised resistance training background over a 10-year period and eight controls of similar age (mean ag…
Changes in neurophysiologic markers of visual processing following beneficial anti-VEGF treatment in macular degeneration
Pasi Vottonen,1 Kai Kaarniranta,1,2 Ari Pääkkönen,3 Ina M Tarkka41Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland; 2Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 3Department of Clinical Neurophysiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 4Department of Health Sciences, University of Jyväskylä, Jyväskylä, FinlandPurpose: Antivascular endothelial growth factor (VEGF) agents have been shown to improve visual acuity and prevent vision loss in exudative age-related macular degeneration. As the vision im…
Alterations in visual and auditory processing in hemispatial neglect: An evoked potential follow-up study
Hemispatial neglect is common after cerebrovascular stroke in the right hemisphere. Cortical electrophysiological studies, especially investigations of both visual and auditory processing in subjects with neglect are sparse. Our purpose was to assess whether and to which extent subjects with neglect may show impairments in both visual and auditory processing. Thereby, we assessed the evolution of changes in sensory processing and neglect symptoms over a 6 month follow-up period. Twenty-one stroke subjects with hemispatial neglect were studied at baseline, 3 weeks later and at 6 months follow-up. At enrollment, 12 patients were in Acute/subacute and 9 were in the chronic stage of stroke. Vis…
Motor Action Execution in Reaction-Time Movements
OBJECTIVE Reaction-time movements are internally planned in the brain. Presumably, proactive control in reaction-time movements appears as an inhibitory phase preceding movement execution. We identified the brain activity of reaction-time movements in close proximity to movement onset and compared it with similar self-paced voluntary movements without external command. DESIGN We recorded 18 healthy participants performing reaction-time and self-paced fast index finger abductions with 306-sensor magnetoencephalography and electromyography. Reaction-time movements were performed as responses to cutaneous electrical stimulation delivered on the hand radial nerve area. Motor field and movement-…
Long-Term Response to Cholinesterase Inhibitor Treatment Is Related to Functional MRI Response in Alzheimer's Disease.
<b><i>Background:</i></b> Treatment of Alzheimer's disease (AD) with cholinesterase inhibitors (ChEI) enhances cholinergic activity and alleviates clinical symptoms. However, there is variation in the clinical response as well as system level changes revealed by functional MRI (fMRI) studies. <b><i>Methods:</i></b> We investigated 18 newly diagnosed mild AD patients with fMRI using a face recognition task after a single oral dose of rivastigmine, a single dose of placebo and 1-month treatment with rivastigmine. The clinical follow-up took place at 6 and 12 months. <b><i>Results:</i></b> MMSE score difference between bas…
Twin studies on the association of physical activity with cognitive and cerebral outcomes
Regular physical activity (PA) offers positive effects on the human body. However, the effects of PA on cognition and in the brain are less clear. In this paper, we narratively review the relationship of PA with cognition and dementia, first from general perspective and then through genetically informed studies on the topic. Then we move on to imaging studies on exercise and brain anatomy first by presenting an overall picture of the topic and then discussing brain imaging studies addressing PA and brain structure in twins in more detailed way. Regarding PA and cognition or dementia, genetically informed studies are uncommon, even though the relationship between PA and cognitive ageing has …
Detecting differences with magnetoencephalography of somatosensory processing after tactile and electrical stimuli.
Abstract Background Deviant stimuli within a standard, frequent stimulus train induce a cortical somatosensory mismatch response (SMMR). The SMMR reflects the brain’s automatic mechanism for the detection of change in a somatosensory domain. It is usually elicited by electrical stimulation, which activates nerve fibers and receptors in superficial and deep skin layers, whereas tactile stimulation is closer to natural stimulation and activates uniform fiber types. We recorded SMMRs after electrical and tactile stimuli. Method 306-channel magnetoencephalography recordings were made with 16 healthy adults under two conditions: electrical (eSMMR) and tactile (tSMMR) stimulations. The SMMR proto…
Virtual reality based robotic therapy for stroke rehabilitation: An initial study
The stroke rate will increase as the population ages. Lots of methods on stroke rehabilitation have been developed in the world. The therapy method based on the mirror box illusion helps the limb practice after stroke. Mirror therapy could be combined to virtual reality (VR) rehabilitation to enhance its effect, using robot to realize the position and force manipulation. Robotic device provide one way to regulate the amount and intensity of movement of the plegic limb and to focus more time on more task-specific and complex functional movements. The purpose of this study is to propose a robot assistant for stroke rehabilitation by utilizing virtual reality technology and sensory feedback, t…
Longitudinal study on modulated corticospinal excitability throughout recovery in supratentorial stroke
Corticospinal excitability (CSE) is modulated by stroke-induced lesions affecting the brain. This modulation is known to be dependent on the timing of the evaluation, and strongest abnormalities are often found in the acute stage. Our study aimed to characterize changes in CSE asymmetry between the affected and the unaffected hemisphere (AH and UH) during the first month after stroke onset and at 6 month follow-up. Neuronavigated transcranial magnetic stimulation (nTMS) was used to assess the CSE of the abductor pollicis brevis (APB) muscle of the hand and tibialis anterior (TA) muscle of the leg in 16 patients over 5 time-points. AH excitability recovered significantly during 6 months, whe…
Functional electrical therapy for hemiparesis alleviates disability and enhances neuroplasticity
Impaired motor and sensory function is common in the upper limb in humans after cerebrovascular stroke and it often remains as a permanent disability. Functional electrical stimulation therapy is known to enhance the motor function of the paretic hand; however, the mechanism of this enhancement is not known. We studied whether neural plasticity has a role in this therapy-induced enhancement of the hand motor function in 20 hemiparetic subjects with chronic stroke (age 53 ± 6 years; 7 females and 13 males; 10 with cerebral infarction and 10 with cerebral haemorrhage; and time since incident 2.4 ± 2.0 years). These subjects were randomized to functional electrical therapy or conventional phys…
Hemispatial neglect reflected on visual memory
PURPOSE Recent studies of hemispatial neglect have revealed both lateralized and nonlateralized attention mechanisms contributing to the syndrome. In addition, neglect patients show impaired spatial working memory and diminished working memory capacity. The aim of this study was to investigate, how neglect would be reflected in their performances in commonly used clinical visual memory tests. METHODS Twelve patients with right hemisphere lesions and left neglect and twelve matched controls were assessed with the Behavioural Inattention Test, the visual reproduction of the WMS-R, the object memory test, the Rey figure test and the list learning test. Visuo-spatial span was explored with the …
Long-term physical activity modulates brain processing of somatosensory stimuli: Evidence from young male twins.
Leisure-time physical activity is a key contributor to physical and mental health. Yet the role of physical activity in modulating cortical function is poorly known. We investigated whether precognitive sensory brain functions are associated with the level of physical activity. Physical activity history (3-yr-LTMET), physiological measures and somatosensory mismatch response (sMMR) in EEG were recorded in 32 young healthy twins. In all participants, 3-yr-LTMET correlated negatively with body fat%, r = −0.77 and positively with VO2max, r = 0.82. The fat% and VO2max differed between 15 physically active and 17 inactive participants. Trend toward larger sMMR was seen in inactive compared to ac…
Comparison of the Behavioural Inattention Test and the Catherine Bergego Scale in assessment of hemispatial neglect.
The objective of the study was to correlate visual and behavioural assessments of hemispatial neglect caused by cerebrovascular accident. We assessed 17 consecutive right-hemisphere stroke patients with hemispatial neglect: the Catherine Bergego Scale (CBS) was used to evaluate neglect in spontaneous behaviour and the conventional subtests of the Behavioural Inattention Test (BIT C) were used to assess visual neglect. The proportional severity of both visual and behavioural neglect was calculated in each individual patient. Dissociations were found between mild neglect in visual screening tasks and moderate or severe neglect in behaviour, although in most patients, neglect was equally evide…
Bilateral activations in operculo‐insular area show temporal dissociation after peripheral electrical stimulation in healthy adults
Interhemispheric transfer is necessary for sensory integration and coordination of body sides. We studied how somatosensory input from one body side may reach both body sides. First, we investigated with 17 healthy adults in which uni‐ and bilateral brain areas were involved in consecutive stages of automatic sensory processing of non‐nociceptive peripheral stimulation. Somatosensory evoked fields (SEFs) to electrical stimulation were recorded with 306‐channel magnetoencephalography in two conditions. First, SEFs were registered following sensory radial nerve (RN) stimulation to dorsal surface of the right hand and second, following median nerve (MN) stimulation at the right wrist. Cortical…
Do adverse events after manual therapy for back and/or neck pain have an impact on the chance to recover? A cohort study.
Background: Manual therapy is a commonly used treatment for patients with back and neck pain. Studies have shown that manual therapy-related adverse events are mainly short in duration and mild or moderate by their intensity, affecting up to 50% of the patients. If the presence of adverse events has an impact on the chance to recover from back/neck pain is poorly understood. The aim of this study was to investigate if mild or moderate adverse events after manual therapy has an impact on the chance to recover from back/neck pain in men and women. Methods: A prospective cohort study of 771 patients with at least three treatment sessions in a randomized controlled trial performed in January 20…
European evidence-based recommendations for clinical assessment of upper limb in neurorehabilitation (CAULIN): data synthesis from systematic reviews, clinical practice guidelines and expert consensus
Abstract Background Technology-supported rehabilitation can help alleviate the increasing need for cost-effective rehabilitation of neurological conditions, but use in clinical practice remains limited. Agreement on a core set of reliable, valid and accessible outcome measures to assess rehabilitation outcomes is needed to generate strong evidence about effectiveness of rehabilitation approaches, including technologies. This paper collates and synthesizes a core set from multiple sources; combining existing evidence, clinical practice guidelines and expert consensus into European recommendations for Clinical Assessment of Upper Limb In Neurorehabilitation (CAULIN). Methods Data from systema…
Automatic auditory and somatosensory brain responses in relation to cognitive abilities and physical fitness in older adults
AbstractIn normal ageing, structural and functional changes in the brain lead to an altered processing of sensory stimuli and to changes in cognitive functions. The link between changes in sensory processing and cognition is not well understood, but physical fitness is suggested to be beneficial for both. We recorded event-related potentials to somatosensory and auditory stimuli in a passive change detection paradigm from 81 older and 38 young women and investigated their associations with cognitive performance. In older adults also associations to physical fitness were studied. The somatosensory mismatch response was attenuated in older adults and it associated with executive functions. So…
Acute Exercise Modulates Pain-induced Response on Sensorimotor Cortex ∼20 Hz Oscillation.
Exercise affects positively on self-reported pain in musculoskeletal pain conditions possibly via top-down pain inhibitory networks. However, the role of cortical activity in these networks is unclear. The aim of the current exploratory study was to investigate the effects of acute exercise on cortical nociceptive processing and specifically the excitability in the human sensorimotor cortex. Five healthy adults (mean age 32.8 years) were recorded with a whole-head 306-channel magnetoencephalography (MEG, Elekta Neuromag® Triux™). Participant’s right hand third fingertip was stimulated electrically with an intracutaneous non-magnetic copper tip electrode before and immediately after an exerc…
Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History : Evidence from Monozygotic Twins
Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 ± 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent ele…
Effect of cholinergic stimulation in early Alzheimer's disease - functional imaging during a recognition memory task.
Treatment of Alzheimer's disease (AD) with acetylcholinesterase inhibitors (AChEI) enhances cholinergic activity and alleviates clinical symptoms. In the present functional magnetic resonance imaging (fMRI) study, we investigated the effect of the AChEI rivastigmine on cognitive function and brain activation patterns during a face recognition memory task. Twenty patients with newly-diagnosed mild AD were administered a single oral dose of placebo, a single dose of rivastigmine (acute), and twice-daily treatment with rivastigmine for 4 weeks (chronic). After each treatment, the patients underwent a facial recognition task during fMRI. The prefrontal areas known to be involved in face recogni…
Long-term physical activity modifies automatic visual processing
Electrophysiologically registered visual mismatch negativity (vMMN) is known to represent automatic visual processing in human visual cortex. Since physical activity (PA) is generally beneficial to cerebrovascular function, we wanted to find out if automatic visual processing is affected by PA. We investigated the connection between long-term leisure-time PA and precognitive visual processing in 32 healthy young males. Participants were divided into active (n = 16) and inactive (n = 16) group according to their leisure-time PA records from the past three years. vMMN was recorded with electroencephalogram using passive oddball paradigm with visual bars. Standard (90%) and deviant (10%) stimu…
Associations of disordered sleep with body fat distribution, physical activity and diet among overweight middle-aged men
This cross-sectional study aimed to investigate whether body fat distribution, physical activity levels and dietary intakes are associated with insomnia and/or obstructive sleep apnea among overweight middle-aged men. Participants were 211 Finnish men aged 30-65 years. Among the 163 overweight or obese participants, 40 had insomnia only, 23 had obstructive sleep apnea only, 24 had comorbid insomnia and obstructive sleep apnea and 76 were without sleep disorder. The remaining 48 participants had normal weight without sleep disorder. Fat mass, levels of physical activity and diet were assessed by dual-energy X-ray densitometry, physical activity questionnaire and 3-day food diary, respectivel…
Evidence of neuroplasticity in the human visual cortex following beneficial anti-VEGF treatment in exudative age-related macular degeneration
Purpose Anti-vascular endothelial growth factor (VEGF) agents have been shown to improve visual acuity and prevent vision loss in exudative age-related macular degeneration (AMD). As the vision improves relatively quickly in response to intravitreal injections, we wanted to know whether this improvement is reflected in electrophysiolocal markers of visual cortical processing. Methods Our interventional case series included 6 elderly patients who underwent injection treatment to the affected eye. Their visual acuity, tomographic images of retinal thickness and visual evoked potentials (VEP) were assessed before of the treatment and six weeks after the last injection. Results All patients sho…
Does chronic pain hinder physical activity among older adults with type 2 diabetes?
Background: Physical activity (PA) is a key component in management of type 2 diabetes (T2D). Pain might be a barrier to PA especially among older adults with T2D, but surprisingly few studies have investigated the association between chronic pain and PA. Our aim was to evaluate the prevalence of chronic pain among older adults with T2D and to examine the association between chronic pain and PA while taking important life-contextual factors into account. Methods: Data of this register-based, cross-sectional study were collected in a survey among adults with T2D (n=2866). In the current study, only respondents aged 65–75 years were included (response rate 63%, n=1386). Data were analysed by …
Comparison of TMS-induced arm acticvation and upper limb functional tests in hemiparetic stroke
Stroke has a major impact in the total cost of healthcare in the Western world as stroke is the most common cause of long-term disability [1]. In attempts to enhance motor recovery after stroke effective treatment strategies have been developed in recent years. Appropriate evaluation of the intervention programs requires comprehensive and accurate assessment of the residual abnormal function. In the present study we compare two well-known clinical functional scoring tests developed for the assessment of hemiparetic upper limb function due to stroke and navigated transcranial magnetic stimulation (nTMS), which measures involuntary target muscle response to cortical stimulation. The aim is to…
Best-corrected visual acuity and retinal thickness are associated with improved cortical visual processing in treated wet AMD patients
Purpose In response to anti-VEGF treatment for wet AMD retinal anatomy and visual acuity is often remedied. In our previous study, we showed that visual evoked potentials (VEP) improve following successful anti-VEGF treatment. The aim of this study was to investigate, how visual acuity and retinal thickness changes are reflected in VEP parameters. Moreover, we wanted to assess the feasibility of VEP as a novel monitoring tool for wet AMD patients. Methods A total of 16 patients and six control subjects were enrolled in this study. Patients received three bevacizumab intravitreal injections. At the beginning of the study and four to 6 weeks after the last injection, the best-corrected visual…
Physical Activity, Fitness, Glucose Homeostasis, and Brain Morphology in Twins
The main aim of the present study (FITFATTWIN) was to investigate how physical activity level is associated with body composition, glucose homeostasis, and brain morphology in young adult male monozygotic twin pairs discordant for physical activity.From a population-based twin cohort, we systematically selected 10 young adult male monozygotic twin pairs (age range, 32-36 yr) discordant for leisure time physical activity during the past 3 yr. On the basis of interviews, we calculated a mean sum index for leisure time and commuting activity during the past 3 yr (3-yr LTMET index expressed as MET-hours per day). We conducted extensive measurements on body composition (including fat percentage …
Design and protocol of Estrogenic Regulation of Muscle Apoptosis (ERMA) study with 47 to 55-year-old women's cohort : novel results show menopause-related differences in blood count
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Perimenopausal women show modulation of excitatory and inhibitory neuromuscular mechanisms.
Background Menopausal transition exposes women to an early decline in muscle force and motor function. Changes in muscle quality and function, especially in lower limbs, are crucial, as they expose individuals to increased risk of falls. To elucidate some of the related neuromuscular mechanisms, we investigated cortical inhibition and peripheral muscle twitch force potentiation in women during the early and late stages of perimenopause. Methods Participants were 63 women aged 48–55 years categorized as early (EP, n = 25) or late (LP, n = 38) perimenopausal according to serum follicle-stimulating hormone (FSH) levels and menstrual diaries. EP women had an irregular menstrual cycle and FSH 2…
Somatosensory mismatch response in young and elderly adults
Aging is associated with cognitive decline and alterations in early perceptual processes. Studies in the auditory and visual sensory modalities have shown that the mismatch negativity [or the mismatch response (MMR)], an event-related potential (ERP) elicited by a deviant stimulus in a background of homogenous events, diminishes with aging and cognitive decline. However, the effects of aging on the somatosensory MMR (sMMR) are not known. In the current study, we recorded ERPs to electrical pulses to different fingers of the left hand in a passive oddball experiment in young (22–36 years) and elderly (66– 95 years) adults engaged in a visual task. The MMR was found to deviants as compared to…
Gait reveals bilateral adaptation of motor control in patients with chronic unilateral stroke.
Background and aims: Functional brain imaging has shown that bilateral brain reorganization may occur after unilateral cerebral damage. The present study searched for evidence of bilateral motor control changes in gait in patients with chronic unilateral stroke. Methods: Gait variables (temporal and spatial parameters, footprint peak times (FPPT) and footfall times (FFT)) were recorded in 48 patients with chronic unilateral stroke at their preferred speed, and in 10 healthy volunteers walking from very slowly to very fast on a pressure sensor walkway. The data were divided into 4 groups according to gait velocity. The functional outcome of stroke was measured by the Barthel Index. Results: …
Older Age Increases the Amplitude of Muscle Stretch-Induced Cortical Beta-Band Suppression But Does not Affect Rebound Strength
Healthy aging is associated with deterioration of the sensorimotor system, which impairs balance and somatosensation. However, the exact age-related changes in the cortical processing of sensorimotor integration are unclear. This study investigated primary sensorimotor cortex (SM1) oscillations in the 15–30 Hz beta band at rest and following (involuntary) rapid stretches to the triceps surae muscles (i.e., proprioceptive stimulation) of young and older adults. A custom-built, magnetoencephalography (MEG)-compatible device was used to deliver rapid (190°·s−1) ankle rotations as subjects sat passively in a magnetically-shielded room while MEG recorded their cortical signals. Eleven young (age…