Dry Needling for Chronic Pain: Unraveling Central Sensitization Through Neurophysiological Mechanisms and Clinical Evidence

Introduction: The Enduring Challenge of Chronic Pain. Millions of individuals worldwide suffer from chronic pain, a widespread and debilitating condition that markedly reduces quality of life and creates significant economic burdens. Unlike acute pain, which typically resolves as tissues heal, chronic pain often persists due to complex changes within the nervous system. Dry needling (DN) is a well-established, evidence-based approach for managing chronic pain. It influences more than just the affected muscles. This blog aims to analyze the intricate role of dry needling in the treatment of chronic pain, including its effects on central sensitization (CS). We will explore the neurophysiological and molecular mechanisms involved supported by substantial fMRI evidence of altered brain processing and high-quality randomized controlled trials (RCTs). Our goal is to provide a comprehensive, evidence-based understanding to improve clinical decision-making, highlighting DN’s potential to address the fundamental causes of chronic pain.

The Enigma of Chronic Pain: Central Sensitization (CS) Defined and Understood

Chronic pain is characterized as pain that persists or recurs for a period exceeding three months. It presents a considerable challenge for healthcare professionals to accurately diagnose and effectively manage. A distinctive feature of chronic pain is the ongoing mismatch between the extent of tissue damage and the severity of pain experienced. This discrepancy often indicates Central Sensitization (CS), a principal factor in chronic pain, commonly classified as nociplastic or neuropathic pain. This phenomenon occurs when the central nervous system processes pain signals in an atypical manner, notwithstanding the absence of conclusive evidence of actual or impending tissue injury.

What is the definition of Central Sensitization (CS)? Central sensitization (CS) is characterized by an amplification of neural signaling within the central nervous system (CNS), resulting in hypersensitivity to pain. Mendell ³ elucidates the historical identification of a neural “windup,” recognized as the initial evidence of activity-dependent plasticity within spinal nociceptive pathways, and its evolution into the concept of central sensitization. This pioneering research demonstrated the plasticity of dorsal horn neurons’ responses to nociceptive stimuli, indicating that repetitive C-fiber stimulation increases neuronal discharge, reflecting alterations in synaptic efficacy and neuronal excitability.

The pathophysiology of chronic pain syndrome, as detailed by Mohabbat and Wilkinson¹ and Nijs et al.², indicates a transition from predominantly peripheral pain mechanisms to a state characterized by central nervous system hypersensitivity. Mohabbat and Wilkinson¹ highlight that disorders based on CS involve structural, functional, and neurochemical alterations within the central nervous system that enhance pain perception. They maintain that chronic pain may originate from continuous peripheral sensory input, thereby modifying the processing of stimuli by the brain and spinal cord, resulting in extensive, migratory symptoms that can occasionally occur in non-anatomic distributions.

This appears as:

Hyperalgesia: An enhanced pain response to a harmful stimulus.
Allodynia: Pain elicited by a stimulus that is typically non-painful.
Referred Pain: Discomfort felt in a location distant from the actual source, often due to the enlargement of receptive fields in dorsal horn neurons. Mendell further elucidates that these phenomena, particularly the expansion of receptive fields, are direct consequences of heightened neural signaling in the dorsal horn.
Reduced Pain Thresholds: Individuals with Central Sensitization (CS) frequently exhibit diminished pressure pain thresholds (PPTs) in both proximal and distal regions.

Ma et al.⁴ (2024) provide an exhaustive examination of the molecular and cellular pathways behind CS, particularly with neuropathic pain (NP):

Glutamatergic Excitatory Transmission: In central sensitization, there is an elevated concentration of excitatory amino acid neurotransmitters, predominantly glutamate (Glu), in the spinal dorsal horn. This leads to heightened activation of N-methyl-D-aspartate receptors (NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR), resulting in increased neuronal excitability. Mendell elucidates that the NMDA receptor is crucial, highlighting that its Mg²⁺ blockade can be mitigated through temporal summation of synaptic depolarization, thereby further enhancing postsynaptic excitability.
Reduced Inhibitory Control: Concurrently, the concentrations of inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA) and glycine (Gly) diminish, impairing the central nervous system’s ability to suppress pain signals. This aligns with Mohabbat and Wilkinson’s description of a decline in typical descending (inhibitory/downregulatory) signaling from the central nervous system.
Activation of Glial Cells: Microglia and astrocytes, essential glial cells in the central nervous system, become activated. These cells secrete several neuroactive chemicals and pro-inflammatory cytokines (such as IL-1β and TNF-α), which further stimulate neuronal excitability and contribute to the persistence of central sensitization (CS). Mohabbat and Wilkinson assert that alterations in cytokine levels and immunological activation are significant pathological factors that initiate chronic stress.
Neurotrophic Factors: Brain-Derived Neurotrophic Factor (BDNF) and its receptor TrkB are crucial. Excessive BDNF in the spinal cord might induce maladaptive plasticity, so reinforcing pain circuits and potentially resulting in chronic pain. Mendell further asserts that BDNF may contribute to central sensitization, particularly in the presence of peripheral inflammation or nerve injury.
Dysfunction of Ion Channels: Modifications in ion channels, particularly P2X4 receptors, play a significant role in the development and maintenance of central sensitization (CS), increasing neuronal excitability and perpetuating a cycle of hyperalgesia.

Mendell³ elaborates on the mechanisms by which neuropeptides, such as Substance P and CGRP, originating from nociceptors, stimulate neurokinin receptors on neurons in the spinal dorsal horn. This induces gradual depolarizations that are crucial for windup and central sensitization. He distinguishes that windup requires synchronous C-fiber volleys for homosynaptic facilitation. In contrast, central sensitization involves a more widespread barrage and may result from heterosynaptic facilitation, which builds over prolonged periods and decays more slowly. CS is fundamentally a neurophysiological condition that amplifies and prolongs the nervous system’s response to pain, even in the absence of new painful stimuli. Addressing this fundamental element is essential for effective chronic pain management.

Dry Needling: A Strategic Method for Modulating Central Sensitization

Considering the intricacies of central sensitization at a neurophysiological level, interventions must transcend mere symptom management; they should actively modify the central nervous system’s information processing. Dry needling (DN), a technique employing a slender filiform needle to penetrate myofascial structures or dysfunctional tissues, is an effective, evidence-based strategy to interrupt the cycle of chronic pain. Although frequently regarded as a localized intervention for musculoskeletal conditions, its substantial effects stem from its capacity to induce neural alterations that modulate central sensitization mechanisms.

The mechanism of dry needling in the control of central sensitization at a neurophysiological level:

Restoration of Inhibitory Control: DN has demonstrated the ability to alter neurotransmitter release in the spinal cord. DN initiates descending inhibitory pathways by activating peripheral nociceptors and mechanoreceptors. This results in an elevation of inhibitory neurotransmitters such as GABA and endogenous opioids. This restores spinal excitability to normal by mitigating the diminished inhibitory control observed in central sensitization. Research demonstrates that DN can increase levels of beta-endorphin and serotonin, which are crucial for descending pain modulation.
The mechanical stimulus of a needle can influence the glutamatergic system. DN can diminish the continuous influx of afferent signals that trigger NMDAR activation and synaptic potentiation in the dorsal horn by reducing peripheral nociceptive input from sensitive tissues. This mitigates the increased neuronal excitability indicative of CS. Moreover, direct needling of active trigger points may mechanically disrupt defective nociceptive circuits, thus reducing their involvement in excitatory transmission.
Mitigating Glial Cell Activation: Sustained peripheral input activates microglia and astrocytes, perpetuating neuroinflammation in the spinal cord. By diminishing this persistent afferent transmission and alleviating tissue discomfort, DN may indirectly attenuate glial activation. The reduction in pro-inflammatory cytokine release (e.g., IL-1β, TNF-α) helps diminish the neuroinflammatory milieu that sustains chronic stress.
The impact on neurotrophic factors and ion channels: While emerging evidence links diabetic neuropathy (DN) to specific changes in brain-derived neurotrophic factor (BDNF) or P2X4 receptors, the overall effect of DN on neural plasticity and ion channel function is suggested by its clinical efficacy in reducing hypersensitivity. DN likely aids in normalizing the expression and function of these critical components of CS by enhancing spinal cord stability, thereby reducing the likelihood of detrimental alterations. The local twitch response, commonly noted during DN, is hypothesized to rapidly desensitize muscle spindles and nociceptors, hence reducing abnormal afferent input that perpetuates central sensitization.

In addition to these specific cellular and molecular effects, dry needling elicits broader physiological changes, including improved blood circulation to the affected region, decreased muscular tension, and a segmental analgesic effect that has the potential to “reset” the body’s dysfunctional pain-processing mechanisms. Dry needling is an exceptional intervention for mitigating the underlying causes of chronic pain, especially in cases arising from central sensitization, owing to its multifaceted mechanisms of action. Temporarily reducing sensory hypersensitivity, which often complicates therapeutic exercise and movement, provides a “window of opportunity” for active rehabilitation and functional restoration.

Neuroimaging Findings: fMRI Demonstrates the Impact of Dry Needling on the Brain

Functional Magnetic Resonance Imaging (fMRI) has yielded crucial insights into the influence of dry needling and acupuncture on brain activity and pain perception, providing objective evidence of their fundamental mechanisms. These research findings demonstrate that the effects of needling extend beyond local tissue, engaging intricate brain networks associated with pain processing, emotional regulation, and cognitive control.

Tong et al.⁵ (2025) conducted an extensive systematic review focusing on neuroimaging findings related to acupuncture for migraine. This review provides essential context by elucidating the brain regions and networks involved in both the acute and preventive effects of acupuncture within this particular population suffering from chronic pain. The middle frontal gyrus (MFG), precuneus, and postcentral gyrus were identified as the regions most directly affected. The majority of these regions are components of the default mode network (DMN), the central executive network (CEN), and the salience network (SN). Key regions associated with preventive effects include the precuneus, anterior cingulate cortex (ACC), and middle frontal gyrus (MFG), which are linked to the default mode network (DMN), salience network (SN), central executive network (CEN), and the descending pain modulatory system (DPMS). This research, in conjunction with an earlier systematic review and meta-analysis conducted by Huang et al. (2012), which thoroughly examined fMRI studies on acupuncture, provides further corroboration for the notion that acupuncture influences an extensive network of brain regions involved not only in somatosensory processing but also in affective and cognitive functions. Huang et al.’s meta-analysis demonstrated that acupuncture, in comparison to rest, consistently activated the supramarginal gyrus, secondary somatosensory cortex (SII), pre-supplementary motor area (pre-SMA), middle cingulate gyrus, insula, thalamus, and precentral gyrus, whereas deactivation was observed in areas such as the subgenual anterior cingulate, amygdala/hippocampal formation, ventromedial prefrontal cortex (vmPFC), nucleus accumbens, and posterior cingulate cortex (PCC).

These findings underscore the substantial neuromodulatory effects of needling procedures, which alter the brain’s mechanisms for pain processing in several ways:

Modulation of Pain Matrix Activity: Research by Dhond et al.⁷ (2007) showed that acupuncture in chronic pain patients caused deactivation of pain-related regions (such as the ACC and insula) and activation of areas linked to pain inhibition (such as the periaqueductal gray, PAG). Similar findings have been seen with dry needling, suggesting its potential to change how the brain processes harmful inputs.
The impact on the Default Mode Network (DMN): Chronic pain is frequently associated with altered functional connectivity within the Default Mode Network (DMN)⁸, a network comprising brain regions activated during rest and self-referential thought. Malfunctions within the DMN can affect an individual’s perception of pain and their cognitive and emotional responses to chronic discomfort. Evidence indicates that acupuncture and dry needling procedures facilitate the restoration of DMN activity and connectivity, thereby enhancing pain perception and alleviating related psychological distress. This normalization suggests a transition of the brain from an excessive focus on pain towards a more adaptable and balanced state.
Activation of Descending Pain Modulatory Systems: A significant finding from functional magnetic resonance imaging (fMRI) research is the stimulation of endogenous descending pain modulatory systems through needling therapies. The periaqueductal gray (PAG) and rostroventromedial medulla (RVM) are essential components of these systems, as they release neurotransmitters such as serotonin and norepinephrine that inhibit the transmission of pain signals to the spinal cord. The study conducted by Napadow et al.⁸ (2007) utilized fMRI to demonstrate that acupuncture stimulation activates specific brain regions associated with reported pain alleviation. This evidence suggests that dry needling (DN) can engage the body’s intrinsic analgesic mechanisms, thereby enhancing regulation over central sensitization.
Alterations in connectivity and neuroplasticity: Functional Magnetic Resonance Imaging (fMRI) has demonstrated that the functional connectivity among various brain regions can fluctuate, rather than solely the activity within a single region. For instance, dry needling (DN) has been shown to enhance connectivity between regions involved in sensory discrimination and those associated with emotional processing, indicating a more integrated and less distressing interpretation of sensory data. These alterations highlight the neuroplastic effects of dry needling, supporting a long-term recalibration of pain pathways that is vital for the management of chronic pain syndrome (CPS).
Differentiating between somatosensory and cognitive-affective processing: Some fMRI studies have aimed to clarify how needling affects the sensorimotor aspect of pain versus its cognitive-affective components. DN seems to decrease activity in regions linked to sensory intensity while also lowering activity in areas involved in the emotional experience of pain. This results in significant relief for sufferers of CS.

The neuroimaging findings provide persuasive evidence that needling therapies are not merely supplementary; rather, they represent potent modalities for modulating nervous system function. Dry needling is a sophisticated method aimed at addressing the primary causes of chronic pain, including central sensitization, by altering cerebral activity, enhancing interconnectivity among diverse brain regions, and modifying pain signal transmission throughout the organism. This highlights its significance as an advanced clinical intervention within rehabilitation research and manual therapy.

Clinical Efficacy of Dry Needling for Chronic Pain: Evidence from Randomized Controlled Trials and Reviews

Data from randomized controlled trials and systematic reviews suggest that dry needling is effective for managing chronic pain. Neuroimaging can help reveal its primary effects, but strong clinical trials are necessary to confirm its ability to reduce pain and improve function in practice. Numerous high-quality RCTs and systematic reviews have examined the impact of dry needling on people with chronic musculoskeletal pain, many of whom exhibit signs of central sensitization. Let’s look at a few examples.

Dry Needling for Knee Osteoarthritis: Dunning et al.¹² (2018) conducted a multicenter randomized clinical trial to investigate the efficacy of periosteal electrical dry needling (DN) as an adjunct to exercise and manual therapy for knee osteoarthritis (OA). Knee osteoarthritis is a disorder frequently associated with elements of central sensitization, indicating that the pain is more severe than localized to the knee joint alone. The study randomly allocated 242 people to receive either electrical DN combined with manual therapy and exercise, or exclusively manual therapy and exercise. Dunning et al.¹² (2018) identified many significant findings:

Significant Enhancement in Disability: Participants who underwent electrical DN, manual therapy, and exercise exhibited markedly greater improvements in their disability (WOMAC Osteoarthritis Index) at both 6 weeks and 3 months compared to those who received only manual therapy and exercise. Effect sizes were modest at 6 weeks and substantial at 3 months, indicating that the treatment provided significant therapeutic advantages.
The electrical DN group exhibited significantly reduced knee pain (Numeric Pain Rating Scale) at both 6 weeks and 3 months. Patients who had electrical DN were 1.7 times more likely to have totally ceased pain medication after three months, indicating reduced drug dependence.
The successful outcome rates indicate that a significantly greater proportion of patients in the dry needling group (75%) achieved a favorable result compared to those in the non-dry needling group (18%). The number needed to treat (NNT) was low (1.78), indicating that dry needling is a highly effective intervention.

The findings provide strong evidence that electrical dry needling, applied with a defined periosteal procedure, can significantly enhance outcomes in patients with knee osteoarthritis, addressing both regional tissue pathology and possibly influencing central pain processing. The scientists noted that optimum needle depth and periosteal stimulation may be crucial for attaining these improved outcomes, potentially influencing deeper neurophysiological changes.

Dry Needling for Cervical Pain Induced by Mechanics: Aleid et al.¹³ (2025) conducted a comprehensive review and meta-analysis that aggregated data on the efficacy of dry needling (DN) in alleviating pain and enhancing functionality in patients with chronic mechanical neck pain. This condition often involves central sensitization, leading to sustained discomfort and heightened movement difficulties. The meta-analysis incorporated nine randomized controlled trials (RCTs) involving a total of 540 participants. Aleid et al.¹³ (2025) identified several significant findings:

The Pain Pressure Threshold (PPT) improved dramatically with DN, indicating a reduction in localized pain hypersensitivity, a common feature of centrally sensitized diseases.
Neck Impairment Index (NDI) Enhancement: The NDI score for the DN group significantly increased, indicating an overall improvement in neck function and a reduction in impairment.
Cervical Range of Motion (ROM): DN exhibited significant enhancements in cervical flexion and right rotation. Nonetheless, no significant disparities were observed in extension, left rotation, or lateral flexion, indicating that the effect was likely more localized or restricted to particular motions.
The review indicated that the DN group had significantly lower NPRS scores compared to the control group, hence substantiating its efficacy in pain alleviation.

The authors conclude that dry needling (DN) appears effective for the short-term alleviation of pain and enhancement of functional outcomes in cases of mechanical neck discomfort. This finding aligns with the conception that DN can mitigate central sensitization by modifying localized trigger points and reducing peripheral nociceptive input. The overall quality of evidence was acknowledged as a limitation because of the inclusion of studies with a high risk of bias; nevertheless, the consistent upward trends observed across numerous outcomes are promising.

Dry Needling for Chronic Lumbar Pain: A prospective, randomized, single-blinded trial conducted by Rajfur et al.¹⁴ (2022) examined the effectiveness of a novel dry needling protocol in alleviating pain intensity and enhancing functional capacity among individuals suffering from chronic low back pain (LBP) attributable to L5-S1 discopathy. Central sensitization often aggravates chronic low back pain. Forty patients were randomly allocated to two groups: an experimental group receiving dry needling grounded in the Five Regulatory Systems concept, and a control group receiving a placebo. Both groups were subjected to consistent medical treatment and participated in physical exercise. The study identified significant benefits within the DN group:

Substantial Pain Alleviation: The DN group exhibited markedly lower pain levels (assessed by the Visual Analog Scale, VAS) compared to the control group (p < 0.001) at all assessment intervals (immediately post-therapy, 1 month, and 3 months). The most effective analgesia occurred immediately following the treatment.
The experimental group demonstrated substantial differences in functional efficiency (Oswestry Disability Index, ODI) relative to the control group at all measurement intervals (p < 0.001). Post-treatment, the DN group exhibited a significant reduction in ODI scores, indicating improved functional capabilities.
The DN group showed a significant improvement in lower spine range of motion, as measured by the Schober test, compared with the control group.

Rajfur et al.¹⁴ found that the novel DN program, when combined with an exercise regimen, alleviated pain and improved function in patients with LBP. This indicates that DN can provide both immediate alleviation and sustained improvements. Furthermore, this suggests that it may be effective in addressing the diverse etiologies of chronic low back pain, such as central sensitization, by modulating both peripheral and central mechanisms involved in pain processing.

Conclusions

Chronic pain, intricately linked to central sensitization (CS), presents a considerable challenge within healthcare. Understanding the complex neurophysiological and molecular mechanisms underlying CS is essential for developing effective treatments. Dry needling for chronic pain is a well-supported, evidence-based intervention for cervical syndrome (CS) that significantly impacts both the peripheral and central nervous systems.

Functional magnetic resonance imaging (fMRI) findings offer substantial insights into the mechanisms through which dry needling and acupuncture activate and reset brain regions associated with pain processing, emotional regulation, and cognitive control. These therapies modify the pain matrix, restore normal functioning within the default mode network (DMN), activate descending pain-modulation systems, and promote beneficial neuroplastic changes. Systematic reviews and meta-analyses consistently demonstrate that dry needling can effectively influence both the physical and psychological dimensions of pain, establishing it as a comprehensive approach to pain management.

Moreover, substantial clinical evidence from randomized controlled trials demonstrates the tangible benefits of dry needling for particular chronic pain conditions. Dry needling significantly reduces disability, pain, and analgesic use in knee osteoarthritis. In instances of mechanical neck discomfort, it increases pain pressure thresholds, reduces neck impairment, and improves specific ranges of motion. It also alleviates chronic low back pain, thereby enhancing both comfort and productivity.

This body of research indicates that dry needling may serve as a sophisticated and precise clinical instrument. Dry needling is an advanced technique that alleviates symptoms, restores functionality, and enhances the quality of life for millions suffering from chronic pain by addressing the underlying reasons of persistent discomfort, including central sensitization. This dual strategy, addressing both peripheral and central body regions, renders dry needling a significant instrument in rehabilitation science and manual therapy. It additionally facilitates more targeted and efficient methods for managing chronic pain. Clinicians aspiring to excel in the treatment of chronic pain disorders must acquire these principles through recognized, evidence-based education. To receive this industry-leading evidence-based education, visit Structure & Function Education’s® course offerings, starting with Foundations in Dry Needling for Orthopedic Rehab & Sports Performance, or visit our upcoming courses page.

References

Brian Hortz, PhD AT

Born in Camden, NJ, Brian received a B.A. in physical education with a concentration in sports medicine from Denison University, a masters degree in sports medicine from Ohio University and his doctoral degree in Exercise Science from Ohio State University. Dr. Hortz is an Instructor and the Director of Research and Education for Structure & Function Education. He has been teaching with Structure & Function Education for several years. Dr. Hortz teaches the Foundations and Advanced courses. In addition to his work with Structure & Function Education, he also has a concierge practice and continues to work one-on-one with athletes to make them well.

Full Bio