How does acupuncture suppress focal epilepsy and improve epilepsy-induced sleep disruption?

Acupuncture therapy can control focal epilepsy and improve epilepsy-induced sleep disruption through modulation of opioid receptors in the brain, according to an epilepsy model study recently published in Journal of Biomedical Science.

In epilepsy, focal seizure refers to a seizure that starts in, and affects just a part of brain. It might affect a large part of hemisphere or just a small area of one of brain lobes. Symptoms of focal seizure depend on the affected brain area and their function. Some simple focal seizures are sometime called “warnings” or “auras” because for some people simple focal seizure can develop into secondarily generalized seizure. So it is important to have an effective treatment for focal seizure and prevent it develop into more severe generalized seizure. Acupuncture is effective in treat focal epilepsy. However the underlying mechanism is unclear.

Recently scientists in Taiwan, China tried to elucidate the mechanism of acupuncture action on a focal epilepsy model with sleep disruption. Before acupuncture epileptic model showed a focal epilepsy and decreased rapid eye movement sleep and non rapid eye movement sleep. Acupuncture at acupoint BL20 with low-frequency 30 min a day for 3 consecutive days suppressed focal epilepsy and epilepsy-induced sleep disruption. The therapeutic effect of electroacupuncture was blocked by naloxone, an opioids receptor antagonist.

The authors suggest that low-frequency electroacupuncture is beneficial to focal epilepsy and its action is modulated through brain opioid receptors.

Reference:

Yi PL et al., Low-frequency electroacupuncture suppresses focal epilepsy and improves epilepsy-induced sleep disruptions. J Biomed Sci. 2015 Jul 7;22(1):49. doi: 10.1186/s12929-015-0145-z.    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4491875/

Potential mechanisms of acupuncture treatment for epilepsy

Although acupuncture including auricular acupuncture is very effective in treating epilepsy the mechanism underlying its effectiveness is not clear. Recently many biomedical studies of acupuncture on epileptic models may help to shed light on those issues.

Epilepsy has been recognized as a disorder of brain excitability characterized by recurrent unprovoked seizures that arise from abnormal, excessive and synchronous activities of clusters of nerve cells in the brain. Epileptic hyperexcitability is believed involved in many factors, among them the important determinant is the intrinsic electrogenic property of neurons that depend on the function of ion channels, such as Na+, K+ and Ca+ channels in cell membrane. In particular, Na+ channels are responsible for the initiation and propagation of action potential, and are critical determinants of intrinsic neuronal excitability. Many studies reported that acupuncture stimulation at specific acupoints increased the release of opioid peptides and their receptors including delta-opioid receptors, which were reported to have inhibited Na+ channel activity, leading to acupuncture’s antiepileptic effect.

A brain region, the thalamus is also believed to play an important role in the epilepticgenesis. Because the close connection between brain cortex and thalamus and the abnormal hypersynchronized oscillation in the thalamocortical network being linked to some forms of epilepsy. It has been reported that acupuncture stimulation at acupoint GV14 inhibited epileptiform activities in the ventral lateral thalamic neurons.

These studies suggest that acupuncture signals generated from activation of receptors surrounding acupoint conveyed to the spinal cord or medullar, then projected to the thalamus, activated opioid system leading to the inhibition of epileptic hyperexcitability.

References:

Chen S et al., Acupuncture for Refractory Epilepsy: Role of Thalamus. Evidence-Based Complementary and Alternative Medicine. Volume 2014 (2014), Article ID 950631, 8 pages.   http://www.hindawi.com/journals/ecam/2014/950631  

Chao D et al., From Acupuncture to Interaction between 𝛿-Opioid Receptors and Na+ Channels: A Potential Pathway to Inhibit Epileptic Hyperexcitability. Evidence-Based Complementary and Alternative Medicine. Volume 2013, Article ID 216016, 17 pages. 
http://www.hindawi.com/journals/ecam/2013/216016/ 

Acupuncture therapy for drug-resistant epilepsy

Epilepsy is a neurological disorder where recurrent seizures are caused by abnormal electrical discharges from the brain and incurs devastating effects on both patients and their families. Most seizures can be controlled by a single antiepileptic drug. Unfortunately some patients require more than one antiepileptic medication to control their seizures. Drug-resistant epilepsy is a seizure that has failed to respond to at least one monotherapy treatment with a standard antiepileptic drug. Vagus nerve stimulation has been used to drug-resistant epilepsy. During the process of vagus nerve stimulation, the left vagus nerve was stimulated by an implanted electrode which sometimes causes the safety and practicability issues.

Acupuncture techniques can be classified in two major categories: one is non-invasive technique, including acupressure, auricular acupuncture and transcutaneous electrical stimulation; and the other is invasive technique, including needles and electroacupuncture. Recently as transcutaneous auricular vagus nerve stimulation is used as an alternative therapy for drug-resistant epilepsy. In a pilot study, 47 of 50 patients with drug-resistant epilepsy completed the 24-week treatment, during treatment 3 patients dropped off. After 8-week treatment 6 of 47 patients (12%) showed no seizure and 12 patients (24%) had reduced seizure frequency. By the end of 24-week treatment, 8 patients (16%) were seizure free and 19 patients (38%) displayed reduction in seizure frequency.

The results of the study showed that transcutaneous auricular vagus nerve stimulation, one type of acupuncture therapies, is effective in suppress epileptic seizures and is a safe and economical treatment option for drug-resistant epilepsy.

Reference:

P Rong et al., (2014) Chin Med J, 127 (2):300-304.
http://www.ncbi.nlm.nih.gov/pubmed/24438620