Effect of Cerebellar Fastigial Nucleus Stimulation Combined With Sling Exercise on Motor Function in Hemiplegic Stroke Patients

This study delivers an in-depth technical and mechanistic elaboration of a novel central-peripheral synergistic rehabilitation paradigm for post-stroke hemiplegia, focusing on the combined application of Fastigial Nucleus Stimulation (FNS) and Sling Exercise Training (SET). It primarily expands on the neurophysiological rationale, technical intervention characteristics, synergistic working mechanisms, optimized trial design logic, standardized quality control and core innovative connotations of the combined intervention, avoiding repetitive descriptions of basic trial elements including participant eligibility, outcome measures, sample size calculation and statistical analysis plans. Targeting the key technical bottleneck of conventional post-stroke rehabilitation-non-specific central neural regulation and superficial muscle activation that fails to reverse pathological neural plasticity-this study focuses on the core deficit of cerebello-thalamo-cortical circuit dysfunction and insufficient deep sensorimotor pathway activation, aiming to develop a targeted, high-efficiency combined rehabilitation technical system.

Persistent motor dysfunction after stroke is not limited to superficial limb movement impairment, but essentially stems from defective central motor regulation and disrupted trunk deep sensorimotor integration. Conventional physical therapy mainly concentrates on passive joint protection and superficial limb functional training, which can only prevent secondary complications such as muscle atrophy and joint contractures. However, it lacks targeted modulation of the central balance and motor coordination hub, and cannot reverse stroke-induced neural plasticity inhibition. This leads to persistent deficits in core stability, proprioceptive acuity and dynamic balance, fundamentally restricting the recovery of fine motor skills and daily living function. To address this clinical technical gap, the present study constructs a bidirectional rehabilitation loop integrating precise central neuromodulation and high-sensitivity peripheral sensorimotor training, realizing organic combination of central neural priming and peripheral sensory feedback remodeling.

FNS is a refined, anatomically targeted non-invasive cerebellar neuromodulation technique with unique advantages over broad cortical stimulation modalities. It precisely targets the fastigial nucleus, the core functional node of the cerebellar motor regulatory network, to specifically activate the cerebello-thalamo-cortical neural circuit. This intervention upregulates the excitability of motor-associated cortical regions, enhances local cerebral microperfusion in motor functional areas, and reverses the post-stroke inhibitory state of endogenous neural plasticity. The high-frequency, low-intensity stimulation paradigm adopted in this study is technically optimized for stroke neural repair. It stably induces activity-dependent neural remodeling without triggering cortical over-excitation or neural fatigue, effectively improving the central nervous system's capacity for sensory information integration and precise motor command output, and building a favorable neurophysiological microenvironment for peripheral motor function reconstruction.

SET represents an upgraded sensorimotor integration training technology that breaks the inherent limitations of traditional planar rehabilitation training. By creating an unstable suspension mechanical environment, SET actively triggers autonomous fine regulation of deep trunk stabilizers, including the transversus abdominis and multifidus muscles, which are rarely activated by conventional training methods. The continuous unbalanced mechanical stimulation generated during training elicits high-density proprioceptive afferent signals from trunk and limb muscles, tendons and joints, activates complete human closed kinetic chains, and drives use-dependent functional reorganization of the sensorimotor cortex. Compared with conventional peripheral training, SET significantly improves the accuracy of somatic sensory input and the efficiency of neuromuscular recruitment, serving as a core technical means to improve dynamic balance, trunk control and gait symmetry in post-stroke patients.

The prominent technical innovation of this research lies in the "central priming + peripheral reinforcement" synergistic intervention mechanism, which targets the self-perpetuating pathological vicious cycle of post-stroke motor dysfunction. Central circuit damage after stroke disrupts normal motor command generation, inducing peripheral disuse muscle atrophy and proprioceptive degradation; in turn, distorted peripheral sensory feedback fails to provide effective remodeling stimuli for the central nervous system, further aggravating motor control disorders. The combination of FNS and SET effectively interrupts this pathological cycle. FNS pre-activates and primes the central cerebello-thalamo-cortical pathway to enhance central neural sensitivity to peripheral sensory signals. On this optimized central neural basis, SET delivers high-fidelity, multi-dimensional proprioceptive afferent input, which acts on the primed central circuit, strengthens synaptic connection efficacy via Hebbian plasticity, and produces superposed and amplified therapeutic effects-achieving a genuine synergistic "1+1>2" effect beyond the simple additive efficacy of single interventions.

A rigorous randomized, double-blind, sham-controlled parallel-group design is adopted in this study to ensure objective and accurate verification of the synergistic therapeutic effect, with optimized sham intervention settings to eliminate systematic bias. The sham FNS protocol applies subthreshold low-intensity current that produces identical cutaneous sensory perception without activating neuronal circuits, while sham SET maintains consistent suspension posture and environmental conditions as active training but excludes voluntary neuromuscular contraction. This standardized double sham-control system effectively isolates placebo effects and individual intervention efficacy, enabling accurate differentiation of the independent therapeutic contributions of FNS-mediated central neuromodulation and SET-mediated peripheral sensorimotor training, and providing reliable technical verification for the specific synergistic effect of central-peripheral co-intervention.

All intervention procedures implement unified standardized technical specifications to ensure trial homogeneity and reproducibility. FNS stimulation adopts standardized bilateral mastoid positioning to precisely target fastigial nucleus projection areas, with all stimulation parameters optimized based on existing neuromodulation mechanism evidence to guarantee stable and effective central neural priming. All SET interventions are delivered by professionally certified rehabilitation therapists, with real-time individualized adjustment of training difficulty based on patients' motor control level and fatigue status. The progressive unstable suspension training mode ensures sustained, graded sensorimotor stimulation, avoiding the dual defects of insufficient stimulus intensity and excessive training load existing in fixed conventional training protocols.

A full-process safety and quality control system is established to standardize intervention implementation and protect participant safety. For FNS neuromodulation, real-time sensory monitoring is conducted throughout stimulation sessions; mild adverse reactions such as local tingling and headache are managed by parameter adjustment or temporary stimulation suspension to ensure good neurological tolerance. For SET training, pre-experiment equipment safety inspection and whole-process therapist supervision are mandatory to prevent muscle strain, excessive fatigue and fall risks. Individualized training intensity matching is implemented for patients with different motor function levels to balance training efficacy and safety. All adverse events are recorded in detail and managed hierarchically to ensure standardized and consistent trial implementation.

In summary, this study focuses entirely on technical innovation, neurophysiological mechanisms and synergistic principles of combined central-peripheral rehabilitation, without redundant description of routine trial baseline elements. Its core research value lies in elucidating the synergistic rehabilitation mechanism between fastigial nucleus central neuromodulation and deep core peripheral sensorimotor activation, establishing a standardized, safe and minimally invasive combined rehabilitation technical system, and providing high-level mechanistic and clinical evidence for optimizing individualized rehabilitation strategies for post-stroke hemiplegia.