Academic Exchange · Stroke & Acupuncture

Acupuncture for Post-Stroke Sequelae: A Narrative Review of Neurologic Mechanisms and Key Acupoints

Summary and clinical–mechanistic discussion based on: Zhang et al., Brain Research Bulletin, 2024.

1. Introduction

Stroke is a leading cause of long-term disability and is frequently followed by complex neurologic sequelae, including motor dysfunction, swallowing disorders, sensory disturbances, and psychiatric or cognitive impairments. These conditions arise from ischemic neural injury, disruption of structural and functional networks, excitotoxicity driven by excessive glutamate (Glu), neuroinflammation, and impaired neuroplasticity.

Over the past two decades, acupuncture has attracted increasing interest as an adjunctive strategy in post-stroke rehabilitation. Preclinical and clinical studies suggest that acupuncture can modulate neuroplasticity, re-organize cortical networks, regulate neurotransmitters such as Glu and γ-aminobutyric acid (GABA), attenuate inflammatory cascades, and improve regional cerebral blood flow and energy metabolism. This review synthesizes evidence on acupuncture’s mechanisms and highlights major acupoints used for stroke-related motor, swallowing, sensory, emotional, cognitive, and language dysfunctions.

2. Motor Dysfunction

2.1 Post-stroke hemiparesis

Post-stroke hemiparesis, characterized by reduced voluntary motor control on the side contralateral to the cerebral lesion, is among the most common and disabling sequelae. Clinically it presents with muscular flaccidity, sluggish limb movements, and inability to perform daily activities with the affected limb. Recovery depends heavily on restoration of upper and lower limb motor circuits, where acupuncture and electroacupuncture have been extensively applied.

The acupoints ST36 (Zusanli) and GB34 (Yanglingquan) are frequently used, alone or in combination, for post-stroke motor rehabilitation. Scalp acupuncture over the bilateral “anterior parietal–temporal oblique region” is also commonly employed for central limb motor dysfunction. Functional MRI studies indicate that acupuncture at GB34 can modulate inter-subject functional correlations in brain regions related to motor and sensory imagery of the limbs, face, tongue, and larynx, with stronger responses in the early post-stroke phase.

2.1.1 Clinical evidence

Randomized controlled trials (RCTs) have shown that patients receiving scalp acupuncture in addition to conventional rehabilitation achieve greater improvements in Fugl–Meyer Assessment (FMA), manual muscle testing (MMT), activities of daily living (ADL), Barthel Index, and NIH Stroke Scale scores compared with control groups. Patients with milder baseline impairment show broader cortical responses to acupuncture, especially in contralateral upper and lower limb cortices, highlighting the importance of residual plasticity.

2.1.2 Basic mechanisms: CST remodeling and neuroplasticity

The corticospinal tract (CST) is the principal motor conduction pathway from cortex to spinal motor neurons, and the extent of CST involvement by infarction is strongly correlated with motor prognosis. In rodent middle cerebral artery occlusion (MCAO) models, electroacupuncture at ST36 and PC6 (Neiguan) reduces modified Neurological Severity Scores and infarct volume, while enhancing expression of neuroplasticity-associated proteins such as GAP-43 and synaptophysin (SYN). These changes promote CST axonal sprouting in cervical segments C1–C4 and support cortical reorganization. Diffusion MRI studies in humans further indicate that scalp acupuncture combined with low-frequency repetitive transcranial magnetic stimulation increases CST fractional anisotropy, consistent with improved white matter integrity and better motor outcomes.

2.2 Post-stroke spasticity (PSS)

PSS is a major complication that can cause pain, abnormal posture, reduced range of motion, and difficulties with hygiene and mobility. Standard management includes stretching, splinting, oral antispastic agents, and botulinum toxin-A injections, but these approaches are limited by cost, side effects, and transient efficacy. Acupuncture has therefore emerged as an attractive adjunctive option.

Clinical trials have shown that electroacupuncture combined with biofeedback, or added to standard rehabilitation, can reduce spasticity scores, increase muscle strength, and improve gait parameters. Improvements in Clinical Spasticity Index (CSI) and Modified Ashworth Scale (MAS) scores are accompanied by better FMA and Barthel Index outcomes.

2.2.1 Modulation of neurotransmitter balance (Glu/GABA)

One core mechanism of PSS is an imbalance between excitatory Glu and inhibitory GABA in central motor circuits. Several key acupoints have been shown to modulate this balance:

• A seminal study by Liu et al. demonstrated that acupuncture at GV26 (Shuigou/Renzhong) preserves post-stroke neurotransmitter homeostasis. Treatment significantly reduced excessive Glu release into cerebrospinal fluid while maintaining endogenous GABAergic inhibition, thereby providing a neuroprotective effect against stroke-induced injury.
• Another study targeting DU14 (Dazhui), BL26 (Guanyuanshu), and RN12 (Zhongwan) in MCAO rats showed marked decreases in Glu expression and up-regulation of GABA in the brainstem. These changes were associated with improved muscle tone and reduced spasticity in the affected limbs, underscoring the therapeutic potential of neurotransmitter modulation in stroke recovery.

In addition, animal work suggests that electroacupuncture can reduce the proportion of type I muscle fibers in spastic muscles, normalize muscle architecture, and improve sonographic parameters such as pennation angle, fascicle length, and muscle thickness. Together with normalization of Hmax/Mmax ratios, these findings indicate that acupuncture can exert bidirectional regulation on muscle tone through both central and peripheral mechanisms.

3. Swallowing Dysfunction (Post-stroke Dysphagia)

Post-stroke dysphagia (PSD) is highly prevalent, affecting up to 80–90% of stroke survivors in the acute and subacute phases. It is linked to lesions involving cortical and subcortical swallowing networks and is strongly influenced by reorganization of bilateral cortical representations of pharyngeal musculature.

The primary acupoint for swallowing dysfunction in the reviewed work is RN23 (Lianquan), often combined with DU16 (Fengfu). RN23 is traditionally indicated for dysphagia, aphasia, loss of voice, hoarseness, and other stomatognathic disorders, and is located in a region richly innervated by cranial nerves involved in swallowing.

3.1 Motor and sensory conduction pathways from CV23/RN23

Animal studies show that electroacupuncture at RN23 enhances local field potentials in the primary motor cortex (M1) of the non-infarcted hemisphere, particularly affecting layer 5 pyramidal neurons that project to swallowing musculature. This leads to increased motor conduction velocity of the hypoglossal nerve, stronger electromyography signals in the mandibuloglossus muscle, reduced swallowing muscle paralysis, increased substance P release, and restoration of drinking ability.

From a sensory perspective, electroacupuncture at RN23 improves blood perfusion and neuronal activity in the primary sensory cortex (S1). TRPV1 channels, highly expressed in sensory neurons near RN23, are up-regulated, contributing to local perfusion changes. Collectively, these findings support a dual-pathway model in which RN23 influences PSD recovery via motor (M1–hypoglossal) and sensory (TRPV1–S1) conductions.

4. Sensory Dysfunction

Post-stroke sensory dysfunction commonly manifests as pain syndromes, most notably central post-stroke pain (CPSP) and hemiplegic shoulder pain (HSP). These conditions are often severe, persistent, and resistant to conventional analgesics, substantially limiting quality of life.

4.1 Central post-stroke pain (CPSP)

CPSP is a neuropathic pain syndrome arising from lesions in central somatosensory pathways. It typically presents as burning, throbbing, or tingling pain affecting the hemibody, and is usually treated with analgesics, antidepressants, or anticonvulsants such as carbamazepine, often with limited efficacy and considerable side effects.

Acupuncture has been reported to provide analgesic effects comparable to oral carbamazepine with fewer adverse reactions. In CPSP rat models established by cobra venom injection into the ventral posterior lateral (VPL) nucleus, electroacupuncture at LI11 (Quchi) and LI10 (Shousanli) increased mechanical pain thresholds and modulated multiple pathways, including oxytocin signaling, cAMP signaling, and GABAergic synaptic transmission. A key pain-related molecule, ADCY1, was up-regulated in CPSP animals and normalized by electroacupuncture, suggesting an important molecular target in chronic pain modulation.

4.2 Hemiplegic shoulder pain (HSP)

HSP predominantly affects the hemiplegic side and is often associated with frozen shoulder and shoulder subluxation. Frozen shoulder arises from capsular adhesions and stiffness, sometimes secondary to PSS, while subluxation is caused by flaccidity or reduced tone in stabilizing shoulder muscles, leading to downward displacement of the humeral head.

Local acupoints TE14 (Jianliao) and LI15 (Jianyu) are frequently used to treat HSP, shoulder arthritis, paralytic shoulder pain, and contracture. Electroacupuncture at these sites improves pain and shoulder function by dredging meridians, activating blood circulation, strengthening periarticular musculature, and preventing joint dislocation. Musculoskeletal ultrasound studies show that acupuncture can reduce acromiohumeral distance (AHD), acromion–greater tuberosity (AGT), and acromion–lesser tuberosity (ALT) indices, reflecting improved joint alignment and reduced subluxation.

5. Multifaceted Dysfunction: Mood, Cognition, and Language

A substantial proportion of stroke survivors experience not only physical deficits but also psychiatric and cognitive sequelae, including post-stroke depression (PSD), post-stroke cognitive impairment (PSCI), and post-stroke aphasia (PSA). These conditions significantly reduce quality of life and complicate rehabilitation.

5.1 Post-stroke depression (PSD)

PSD is the most common psychiatric complication after stroke. Proposed mechanisms include reduced monoamine neurotransmitters (serotonin, norepinephrine, dopamine), impaired neurotrophic responses, HPA-axis-related inflammation, oxidative stress, and glutamatergic excitotoxicity.

Several acupoints have been investigated for PSD, particularly along the Du (governor) vessel. GV20 (Baihui), which “governs the brain” in traditional theory, is a high-frequency point in depression and cognitive studies. Combined protocols often include GV26 (Shuigou), GV24 (Shenting), and DU14 (Dazhui). Clinical RCTs show that electroacupuncture can improve Hamilton Rating Scale for Depression (HRSD), Zung Self-Rating Depression Scale (SDS), NIHSS, Barthel Index, and TCM syndrome scores, with efficacy increasing over time.

In MCAO plus chronic stress rat models, electroacupuncture at GV20, GV26, GV24, and DU14 improved depression-like behaviours, reduced ultrastructural damage in hippocampal CA1 neurons, and increased levels of norepinephrine, serotonin (5-HT), and dopamine. Work on the “Si Guan” (“Four Gates”) acupoint combination has demonstrated antidepressant effects comparable to fluoxetine, with both interventions up-regulating brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the hippocampus. Additional studies show that electroacupuncture can lower pro-inflammatory cytokines (IL-6, TNF-α), enhance glutathione (GSH) levels, raise 5-HT expression, and improve depression-related behaviours, suggesting a combined anti-inflammatory, antioxidative, and monoaminergic mechanism.

5.2 Post-stroke cognitive impairment (PSCI)

PSCI refers to new cognitive deficits emerging 3–6 months after stroke, distinct from pre-existing decline. It commonly affects abstract reasoning, memory, and orientation. No medications are currently approved specifically for PSCI; cholinesterase inhibitors used in Alzheimer’s disease and vascular dementia have yielded inconclusive results in this population.

Acupuncture at acupoints innervated or modulated via trigeminal pathways, notably EX-HN3 (Yintang) and GV20 (Baihui), has been shown to improve spatial learning and recognition memory in MCAO rats, as assessed by the Morris water maze and novel object recognition tests. Electroacupuncture at GV20 and DU24 (Shenting region) ameliorates cognitive deficits while suppressing hippocampal inflammation, including down-regulation of NF-κB, IL-1, TNF-α, iNOS, and COX-2.

Beyond inflammation, PSCI is tightly linked to impaired cerebral energy metabolism, including abnormal blood flow, mitochondrial function, and glucose utilization. Acupuncture has been shown to increase intracortical blood flow, enhance mitochondrial respiratory control ratio and membrane potential, boost activity of respiratory complexes I, II, and IV, reduce oxidative stress injury, and up-regulate key glycolytic and pentose pathway enzymes such as hexokinase, pyruvate kinase, and glucose-6-phosphate dehydrogenase. At the synaptic level, acupuncture can increase synapse number, restore synaptic morphology and transmission, and enhance synaptic plasticity, thereby improving learning and memory.

5.3 Post-stroke aphasia (PSA)

PSA is an acquired impairment of language processing at morphological, phonological, syntactic, and lexical–semantic levels, typically due to lesions in the dominant hemisphere (often the left hemisphere in right-handed individuals). Approximately 30% of stroke patients develop aphasia. While pharmacotherapy, behavioural speech therapy, and stimulation techniques are used, acupuncture has emerged as a common complementary modality.

Acupuncture has been shown to improve repetition, spontaneous speech, reading, comprehension, and writing abilities. Resting-state fMRI studies indicate that electroacupuncture induces activation in frontal, temporal, parietal, and limbic regions, with activation patterns closely resembling those elicited by picture-naming tasks. In particular, the left inferior frontal gyrus (Broca’s area) shows significant activation, suggesting re-engagement of core language circuits.

Recent work has focused on the effects of HT05 (Tongli) and GB39 (Xuanzhong), among other points, on dynamic brain connectivity. During electroacupuncture at HT05 and GB39, increased connectivity has been observed among cerebellar, default mode, and language networks, which are all important for language and higher cognitive functions. At the molecular level, acupuncture appears to reduce neuronal apoptosis in affected hippocampal regions, promote repair of damaged neurons, and enhance synaptic plasticity via activation of BDNF/TrkB signaling, increased acetylcholine levels in the contralateral hemisphere, facilitation of NMDA receptor-mediated transmission in glutamatergic and dopaminergic neurons, and induction of long-term potentiation (LTP).

6. Summary of Main Acupoints

Stroke sequelae are multifaceted, involving motor, swallowing, sensory, emotional, cognitive, and language domains. Across the reviewed literature, several acupoints recur as “hubs” for specific dysfunctions:

• Motor dysfunction: ST36 and GB34 are core points for acupuncture/electroacupuncture, often combined with scalp acupuncture over the bilateral anterior parietal–temporal oblique region. These acupoints open meridians, activate collaterals and muscles, soothe tendons, and facilitate joint movement while promoting CST remodeling and improving brain functional connectivity.
• Spasticity and tone regulation: GV26, DU14, BL26, and RN12 have been shown in MCAO models to restore Glu/GABA balance, reduce excitotoxicity, and improve muscle tone. These points represent important mechanisms for post-stroke spasticity (PSS) management at the level of neurotransmitter modulation.
• Swallowing dysfunction (PSD): RN23, often combined with DU16, is a primary point for dysphagia, aphasia, and laryngeal disorders. Its therapeutic effects are mediated by improved swallowing response signals, enhanced motor and sensory cortical excitability, and increased local perfusion.
• Central post-stroke pain (CPSP): LI11 and LI10 are key forearm points shown to increase mechanical pain thresholds and modulate oxytocin, cAMP, and GABAergic pathways while normalizing ADCY1 expression.
• Hemiplegic shoulder pain (HSP): TE14 and LI15 are local shoulder points that dredge meridians, enhance circulation, reduce adhesions, strengthen musculature, and prevent shoulder dislocation. Ultrasound indices (AHD, AGT, ALT) support their role in improving joint alignment.
• Mood and cognition: GV20 (often with GV26, GV24, and DU14) is a high-frequency point for depression and PSCI. It helps “awaken” the brain, attenuate inflammatory responses, improve metabolic disturbances, and preserve hippocampal and white matter integrity.
• Cognitive and trigeminal-related modulation: EX-HN3, GV20, and DU24 play important roles in spatial learning, memory, and executive functions, partly through hippocampal anti-inflammatory effects, improved mitochondrial energy metabolism, and synaptic repair.
• Language (PSA): HT05 and GB39, together with scalp language-related regions, have been shown to activate Broca’s area, enhance dynamic connectivity among language and default mode networks, and promote neuroplasticity via BDNF/TrkB and cholinergic/NMDA-mediated mechanisms.

Taken together, these findings underscore acupuncture’s multifaceted role in addressing diverse post-stroke dysfunctions through targeted, network-level neuromodulation and peripheral musculoskeletal effects.

References

Zhang, Y., Tang, Y.-W., Peng, Y.-T., Yan, Z., Zhou, J., & Yue, Z.-H. (2024). Acupuncture, an effective treatment for post-stroke neurologic dysfunction. Brain Research Bulletin, 215, 111035.

Full text via ScienceDirect: https://www.sciencedirect.com/science/article/pii/S0361923024001680