Sensory-motor interregulation in the elderly with stroke
1.1 Characteristics of sensory-motor interregulation in elderly patients with stroke Precise upper limb movement requires coordinated neural activity of the sensory and motor systems. Perceptual-motor interregulation refers to the process of integrating the sense of self and the external environment to form a movement, and reasonably coordinating feedforward and feedback. Upper body somatic senses include superficial senses (temperature, pain, touch, pressure), deep senses and proprioception (kinesis, position, vibration), complex senses (two-point discrimination, figure, etc.). Upper body motor functions include gross motor (such as arm movement) and fine motor (such as writing). Perception-motor interregulation is inseparable from sensorimotor integration (SMI) centers, which often exist in the basal ganglia, thalamus, cerebellum, and cerebral cortex. Sensorimotor integration in the cerebral cortex is accomplished through connections to subcortical structures (such as the thalamus) and intracortical regions. After receiving peripheral sensory input, the thalamus conducts information to layer 4 of the somatoprimary sensory cortex (S1) and primary motor cortex (M1), and neurons in this layer excitably project to layers 2 and 3 of S1 and M1 The horizontal connection of the sensory cortex completes the information transmission between the primary sensory cortex and the motor cortex.
In addition to somatosensory, special senses such as vision also play an important role in sensory-motor interregulation. Visual information passing through the thalamus to the cortex can activate the visual-perceptual bidirectional neurons in the posterior parietal cortex, and facilitate the corresponding neurons of S1, thereby improving the sensitivity and recognition of human touch. Imaging studies have shown that peripheral tactile stimuli elicit increased activity in the visual cortex, implying a bidirectional link between vision and touch. In addition, visual feedback can control the information from the proprioception to the cerebral cortex, and update the physical and mental diagrams stored in the cortex, helping the human body complete the "perception-processing-response" process.
The central nervous system damage in elderly stroke patients is most common in the basal ganglia, thalamus and other parts. The damage to these parts will destroy the SMI, thereby affecting the process of sensory-motor interregulation in patients, resulting in sensory and motor disorders. A cross-sectional study showed that the tactile sense and two-point discrimination of the affected side of the upper limbs in elderly stroke patients were significantly impaired, and the tactile impairment was related to motor function. Studies of stroke outcomes have shown that greater sensorimotor cortical connectivity and better proprioception are associated with better motor outcomes. The above research results suggest that in rehabilitation treatment, the sensory and motor dysfunction of elderly stroke patients should not be treated alone, but a combination of the two is needed to obtain a better functional prognosis.
1.2 Sensitive-motor interregulation method of elderly stroke M1 and S1 have significant bilateral cross-control characteristics with the limbs. At the same time, there are a large number of fiber connections through the corpus callosum in the equal brain regions of the bilateral cerebral hemispheres, which makes the bilateral cerebral hemispheres dynamic. Functional linkages and mutual constraints. The normal left-right balance pattern is an important basis for the normal function of the upper and lower limbs. The sensory-motor dysfunction in elderly stroke patients may be due to the imbalance between the left and right hemispheres of the brain. The excitability of the healthy hemisphere is enhanced while the excitability of the affected brain is suppressed. Based on this theory, sensory-motor interregulation in elderly stroke needs to help patients restore the correct left-right balance mode. The condition of bilateral limbs should be comprehensively considered in the rehabilitation assessment, and the unbalanced relationship in elderly stroke patients should be assessed. In the post-stroke soft paralysis period, the patient needs to maintain the correct good limb position; in the rehabilitation period, it is necessary to carry out check and balance training on the sensorimotor function of the agonist and antagonist muscles, and at the same time, non-invasive brain function adjustment techniques such as repetitive transcranial magnetic stimulation (rTMS) can be used. ), transcranial direct current stimulation (tDCS), etc. to directly adjust the imbalance between the left and right hemispheres of the brain.
Spike timing-dependent plasticity (STDP) is a mechanism by which the sensorimotor system modulates connections between presynaptic and postsynaptic neurons based on their relative firing patterns. For STDP, repeated firing of presynaptic neurons a few milliseconds before postsynaptic neurons can strengthen the synaptic connection between them, called long-term potentiation (LTP); if the postsynaptic neuron is activated first, then The synapse is then inhibited, known as long-term depression (LTD). Based on this mechanism, elderly stroke patients can regulate sensory-motor function by strengthening the SMI site. Sensory-motor system timed activity refers to timed paired stimuli acting on the sensory-motor system and is the most common method of strengthening SMI sites. Timing paired stimulation is a method of collecting at two different parts so that the two stimuli can arrive at the SMI synchronously. Studies have shown that cortical stimulation combined with muscle stimulation can effectively improve sensory-motor regulation in stroke patients. Timing paired stimulation should be combined with the "central-peripheral-central" closed-loop rehabilitation theory, that is, through central interventions such as non-invasive brain stimulation, mirror therapy, brain-computer interface technology, motor imagery therapy, etc. to directly stimulate sensory-motor brain regions , to activate functional brain regions and improve synaptic plasticity; through peripheral interventions such as Bobath technology, proprioceptive neuromuscular facilitation technology, peripheral electrical stimulation technology, etc., to perform rehabilitation treatments for patients in different periods.
The theory of "hand-brain perception" originally proposed that "hand-brain perception" can be used to start the task state of "hand-brain movement". Based on the theory of multisensory integration, this task state promotes the occurrence and execution of motor behavior through different forms of sensory stimulation. For example, designing homework activities to teach patients how to dress and comb hair, etc., the therapist needs to conduct joint training on listening, speaking, reading, writing, touch, recognition and other functions, which is more conducive to the recovery of patients' sensory-motor functions. In addition, in the operation activities, it is advocated to design task-oriented game training, and combine game equipment with upper and lower limb functional training equipment to train patients' attention, visual tracking and motor functions. Rehabilitation training also needs to be completed in tasks in a rich environment. Through stimulation tools or rehabilitation techniques, visualization or masking, it can help the sensory-motor neurons in the brain of elderly stroke patients to analyze and integrate, thereby promoting the recovery of sensory-motor function.
1.3 Sensory-motor interregulation in elderly stroke patients Falls are a common and serious problem in elderly stroke patients. Hospitalized elderly stroke patients are prone to falls when training alone without the supervision of physicians and therapists. Elderly stroke patients returning to their families and society also have various falls risks. The function of maintaining balance in the human body requires the participation of three links: sensory input, central integration, and motor control. These links involve the complex operation of four organs: the visual organ, the proprioceptive organs, the vestibular organs of the inner ear, and the cerebellum. Vision helps the human body to determine the spatial position; the proprioceptors are distributed in the nerve endings of the joints and muscles of the limbs, helping the human body to feel its own position and movement direction information; the vestibular organ of the inner ear acts as an "accelerator", which can help the human body feel the body when the external position changes The movement of the body; the cerebellum plays the role of movement regulation and maintaining body balance. The fall problem of elderly stroke patients is actually a manifestation of the imbalance of sensory-motor interregulation.
Based on the relationship between perception and movement, the fall problem of elderly stroke patients should start from the source, so as to better prevent falls in elderly stroke patients and help patients restore their balance function. If the patient's vision has problems, the patient should be helped to perform balance function training on the premise of visual rehabilitation. Training should be done step by step, and a balance training program that suits the patient's condition should be designed based on the three-level balance. The training method based on the closed-loop theory is also helpful for balance function training. The research published by Koch et al. in JAMA Neurology showed that intermittent θ burst stimulation of the cerebellum combined with lower limb physical therapy can effectively improve the lower limb balance function of stroke patients. The closed-loop training methods of other modes need further research to prove their effectiveness and safety.
1.1 Characteristics of sensory-motor interregulation in elderly patients with stroke Precise upper limb movement requires coordinated neural activity of the sensory and motor systems. Perceptual-motor interregulation refers to the process of integrating the sense of self and the external environment to form a movement, and reasonably coordinating feedforward and feedback. Upper body somatic senses include superficial senses (temperature, pain, touch, pressure), deep senses and proprioception (kinesis, position, vibration), complex senses (two-point discrimination, figure, etc.). Upper body motor functions include gross motor (such as arm movement) and fine motor (such as writing). Perception-motor interregulation is inseparable from sensorimotor integration (SMI) centers, which often exist in the basal ganglia, thalamus, cerebellum, and cerebral cortex. Sensorimotor integration in the cerebral cortex is accomplished through connections to subcortical structures (such as the thalamus) and intracortical regions. After receiving peripheral sensory input, the thalamus conducts information to layer 4 of the somatoprimary sensory cortex (S1) and primary motor cortex (M1), and neurons in this layer excitably project to layers 2 and 3 of S1 and M1 The horizontal connection of the sensory cortex completes the information transmission between the primary sensory cortex and the motor cortex.
In addition to somatosensory, special senses such as vision also play an important role in sensory-motor interregulation. Visual information passing through the thalamus to the cortex can activate the visual-perceptual bidirectional neurons in the posterior parietal cortex, and facilitate the corresponding neurons of S1, thereby improving the sensitivity and recognition of human touch. Imaging studies have shown that peripheral tactile stimuli elicit increased activity in the visual cortex, implying a bidirectional link between vision and touch. In addition, visual feedback can control the information from the proprioception to the cerebral cortex, and update the physical and mental diagrams stored in the cortex, helping the human body complete the "perception-processing-response" process.
The central nervous system damage in elderly stroke patients is most common in the basal ganglia, thalamus and other parts. The damage to these parts will destroy the SMI, thereby affecting the process of sensory-motor interregulation in patients, resulting in sensory and motor disorders. A cross-sectional study showed that the tactile sense and two-point discrimination of the affected side of the upper limbs in elderly stroke patients were significantly impaired, and the tactile impairment was related to motor function. Studies of stroke outcomes have shown that greater sensorimotor cortical connectivity and better proprioception are associated with better motor outcomes. The above research results suggest that in rehabilitation treatment, the sensory and motor dysfunction of elderly stroke patients should not be treated alone, but a combination of the two is needed to obtain a better functional prognosis.
1.2 Sensitive-motor interregulation method of elderly stroke M1 and S1 have significant bilateral cross-control characteristics with the limbs. At the same time, there are a large number of fiber connections through the corpus callosum in the equal brain regions of the bilateral cerebral hemispheres, which makes the bilateral cerebral hemispheres dynamic. Functional linkages and mutual constraints. The normal left-right balance pattern is an important basis for the normal function of the upper and lower limbs. The sensory-motor dysfunction in elderly stroke patients may be due to the imbalance between the left and right hemispheres of the brain. The excitability of the healthy hemisphere is enhanced while the excitability of the affected brain is suppressed. Based on this theory, sensory-motor interregulation in elderly stroke needs to help patients restore the correct left-right balance mode. The condition of bilateral limbs should be comprehensively considered in the rehabilitation assessment, and the unbalanced relationship in elderly stroke patients should be assessed. In the post-stroke soft paralysis period, the patient needs to maintain the correct good limb position; in the rehabilitation period, it is necessary to carry out check and balance training on the sensorimotor function of the agonist and antagonist muscles, and at the same time, non-invasive brain function adjustment techniques such as repetitive transcranial magnetic stimulation (rTMS) can be used. ), transcranial direct current stimulation (tDCS), etc. to directly adjust the imbalance between the left and right hemispheres of the brain.
Spike timing-dependent plasticity (STDP) is a mechanism by which the sensorimotor system modulates connections between presynaptic and postsynaptic neurons based on their relative firing patterns. For STDP, repeated firing of presynaptic neurons a few milliseconds before postsynaptic neurons can strengthen the synaptic connection between them, called long-term potentiation (LTP); if the postsynaptic neuron is activated first, then The synapse is then inhibited, known as long-term depression (LTD). Based on this mechanism, elderly stroke patients can regulate sensory-motor function by strengthening the SMI site. Sensory-motor system timed activity refers to timed paired stimuli acting on the sensory-motor system and is the most common method of strengthening SMI sites. Timing paired stimulation is a method of collecting at two different parts so that the two stimuli can arrive at the SMI synchronously. Studies have shown that cortical stimulation combined with muscle stimulation can effectively improve sensory-motor regulation in stroke patients. Timing paired stimulation should be combined with the "central-peripheral-central" closed-loop rehabilitation theory, that is, through central interventions such as non-invasive brain stimulation, mirror therapy, brain-computer interface technology, motor imagery therapy, etc. to directly stimulate sensory-motor brain regions , to activate functional brain regions and improve synaptic plasticity; through peripheral interventions such as Bobath technology, proprioceptive neuromuscular facilitation technology, peripheral electrical stimulation technology, etc., to perform rehabilitation treatments for patients in different periods.
The theory of "hand-brain perception" originally proposed that "hand-brain perception" can be used to start the task state of "hand-brain movement". Based on the theory of multisensory integration, this task state promotes the occurrence and execution of motor behavior through different forms of sensory stimulation. For example, designing homework activities to teach patients how to dress and comb hair, etc., the therapist needs to conduct joint training on listening, speaking, reading, writing, touch, recognition and other functions, which is more conducive to the recovery of patients' sensory-motor functions. In addition, in the operation activities, it is advocated to design task-oriented game training, and combine game equipment with upper and lower limb functional training equipment to train patients' attention, visual tracking and motor functions. Rehabilitation training also needs to be completed in tasks in a rich environment. Through stimulation tools or rehabilitation techniques, visualization or masking, it can help the sensory-motor neurons in the brain of elderly stroke patients to analyze and integrate, thereby promoting the recovery of sensory-motor function.
1.3 Sensory-motor interregulation in elderly stroke patients Falls are a common and serious problem in elderly stroke patients. Hospitalized elderly stroke patients are prone to falls when training alone without the supervision of physicians and therapists. Elderly stroke patients returning to their families and society also have various falls risks. The function of maintaining balance in the human body requires the participation of three links: sensory input, central integration, and motor control. These links involve the complex operation of four organs: the visual organ, the proprioceptive organs, the vestibular organs of the inner ear, and the cerebellum. Vision helps the human body to determine the spatial position; the proprioceptors are distributed in the nerve endings of the joints and muscles of the limbs, helping the human body to feel its own position and movement direction information; the vestibular organ of the inner ear acts as an "accelerator", which can help the human body feel the body when the external position changes The movement of the body; the cerebellum plays the role of movement regulation and maintaining body balance. The fall problem of elderly stroke patients is actually a manifestation of the imbalance of sensory-motor interregulation.
Based on the relationship between perception and movement, the fall problem of elderly stroke patients should start from the source, so as to better prevent falls in elderly stroke patients and help patients restore their balance function. If the patient's vision has problems, the patient should be helped to perform balance function training on the premise of visual rehabilitation. Training should be done step by step, and a balance training program that suits the patient's condition should be designed based on the three-level balance. The training method based on the closed-loop theory is also helpful for balance function training. The research published by Koch et al. in JAMA Neurology showed that intermittent θ burst stimulation of the cerebellum combined with lower limb physical therapy can effectively improve the lower limb balance function of stroke patients. The closed-loop training methods of other modes need further research to prove their effectiveness and safety.
