Thank you to HealthCMI for this interesting article.

Acupuncture alleviates sciatica and MRIs reveal that acupuncture causes important pain relief related changes in brain functional connectivity. Affiliated Huashan Hospital of Fudan University researchers gathered objective and subjective data in a controlled clinical trial consisting of patients suffering from sciatica. Visual Analogue Scale (VAS) scores indicate that acupuncture produces significant decreases in both pain intensity levels and frequency of pain. Additionally, MRIs show that acupuncture restores pain-free connectivity related activity in the brain; acupuncture changed the functional state of the brain such that patients had greater resting states.

The researchers determined that acupuncture regulates the default mode network (DMN). In addition, the DMN regulation induced by acupuncture treatment correlates to significant reductions in pain for sciatica patients. The DMN is a complex of interconnected activated and deactivated brain regions and the DMN is at its peak activity level when the brain is at rest. Acupuncture facilitated key changes to the brain to allow for the resting state to return. The research indicates that sciatica-related pain disturbs the normal DMN pattern and that acupuncture restores the pattern.

Using functional magnetic resonance imaging (fMRI), the research team discovered that acupuncture “raises negative activation in the brain’s default mode network (DMN) of chronic sciatica patients, especially in the dorsal medial prefrontal cortex and anterior cingulate cortex.” [1] The cingulate cortex and the frontal cortex are known to be involved in pain-related subjective perception and cognition, memory, emotional responses, and attentional responses. [2]

Prior research confirms that decreased negative activation in the DMN is associated with increased pain. Another fMRI study compared chronic lower back pain patients with healthy volunteers. The results showed that patients with chronic lower back pain had significantly decreased negative activation in the default mode network (DMN) of the brain. [3] Negative activation is a form of functional connectivity found during the brain’s resting state. [4]

Symptoms
In the Affiliated Huashan Hospital of Fudan University sciatica research, Visual Analogue Scale (VAS) scores of the acupuncture treatment and control groups were compared before and after treatments. VAS was implemented as an instrument for assessing the intensity and frequency of pain. The scores in the acupuncture treatment group decreased from 5.6 ±1.3 before treatment to 1.2 ±0.8 after treatment. There was a statistically significant difference before and after treatment and the acupuncture group significantly outperformed the control group. The subjective data demonstrates that acupuncture reduces both pain intensity and frequency for patients with sciatica.

Brain Functional Connectivity
The researchers found that negative activation of the DMN in the healthy control group included the following regions: bilateral posterior cingulate, cuneus, precuneus, inferior parietal lobule, dorsal medial prefrontal cortex, and dorsal lateral prefrontal cortex. Prior to acupuncture, the treatment group showed decreased negative activation in the DMN regions as well, including the dorsal medial prefrontal cortex, dorsal lateral prefrontal cortex, anterior cingulate cortex, and precuneus. After acupuncture treatment, the negative activation in these regions increased. Acupuncture produced significant improvements towards the DMN activity found in the healthy control group; however, a slight decrease in negative activation in the precuneus of chronic sciatic patients persisted.

Design
The Fudan University researchers (Li et al.) used the following study design. A total of 20 subjects participated in the study and were divided into two groups, with 10 subjects in each group. The treatment group subjects were selected from the Department of Integrated Traditional and Western Medicine, the Affiliated Huashan Hospital of Fudan University. All were diagnosed with chronic sciatica. The control group subjects included only healthy volunteers. The following selection criteria were applied for the treatment group subjects:

• Consistent with the diagnostic criteria of chronic sciatica: radiating pain in the sciatic nerve distribution area (i.e., buttocks, posterior thigh, posterior lateral lower leg, lateral dorsum of the foot).
• Chronic lower extremity pain for more than 3 months.
• No sedative or analgesic drugs were taken 24 hours before or during acupuncture treatment.
• No acupuncture treatment within 0.5 years before the study.
• The visual analogue scale (VAS) score was ≥5 points.
• Informed consent was signed for each subject.

The following exclusion criteria were applied:

• History of spinal fractures, tumors, and intervertebral disc surgery.
• History of nervous and mental disorders.
• Contraindications for MRI examination (i.e., claustrophobia).

The statistical breakdown for each group was as follows. The treatment group was comprised of 5 males and 5 females. The mean age of the treatment group was 39.5 ±6.0 years. The control group was comprised of 5 males and 5 females. The mean age of the control group was 37.7 ±5.1 years. Both groups were equivalent in all relevant demographics, setting the basis for a fair comparison of results. Only the treatment group received acupuncture treatment. Both groups were scanned twice using fMRIs, once before acupuncture and once after 10 sessions of acupuncture treatment.

Acupuncture Procedure
The primary acupoints selected for the treatment of chronic sciatica were the following:

• BL40 (Weizhong)
• GB30 (Huantiao)

Additional secondary acupoints were added based on symptom presentation. For lower back pain, the following acupoints were added:

• BL23 (Shenshu)
• BL25 (Dachangshu)

For pain radiating to the posterior lower leg, the following acupoint was added:

• BL57 (Chengshan)

Manual acupuncture was applied prior to the application of electroacupuncture. After deqi was achieved at the acupoints, the acupuncture needles were connected to an electroacupuncture device (2 Hz，2–4 mA, 10 V). The needles were retained for 30 minutes starting from the initiation of electroacupuncture stimulation. One 30 minute electroacupuncture session was administered twice daily, 3 times weekly, for a grand total of 10 sessions for each participant. To learn more about acupuncture procedures to alleviate sciatica, visit the following online course:

Lower Back Pain and Sciatica >

Summary
Subjective clinical and objective MRI data indicates that acupuncture is effective for the treatment of chronic sciatica. According to the research, common protocols involve the application of acupoints Weizhong (BL40) and Huantiao (GB30) for this condition. Patients interested in learning more about acupuncture are recommended to contact a local licensed acupuncturist.

References:
[1] Li J, Dong JC, Le JJ, et al. Effects of acupuncture on default mode network images of chronic sciatica patients in the resting network state [J]. Chinese Journal of Integrated Traditional and Western Medicine, 2012, 32(12):1624-1627.
[2] Vogt BA, Derbyshire S, Jones AK. Pain processing in four regions of human cingulate cortex localized with co-registered PET and MR imaging [J]. Eur J Neurosci, 1996, 8 (7): 1461 – 1473.
[3] Baliki MN, Geha PY, Apkarian AV, et al. Beyond feeling: chronic pain hurts the brain, disrupting the default mode network dynamics[J]. J Neurosci, 2008, 28 (6) :1398 – 1403.
[4] Raichle ME, MacLeod AM, Snyder AZ, et al. A default mode of brain function[J]. Proc Natl Acad Sci USA, 2001, 98(2): 676 – 682.