Motor Cortex Plasticity and the Effect of Deep Intramuscular Needling Stimulation Therapy (DIMST) in Osteoarthritis Pain

Hospital de Clinicas de Porto Alegre

Status: Completed

Conditions: Chronic Pain; Knee Osteoarthritis

Treatments: Procedure: DIMST; Procedure: Placebo-sham

Study type: Interventional

Funder types: Other

Identifiers

NCT01855958

11-0013

Details and patient eligibility

About

The aim of this study is to evaluate the cortical excitability in pain of knee osteoarthritis (OA), as well as the effect of one session of a kind of electroacupuncture (deep needling intramuscular stimulation therapy - DIMST) in this pain and the cortical excitability after the intervention.

The hypothesis is that cortical excitability is altered in this condition, confirming the findings already described in other chronic pain conditions. The investigators also believe that a session DIMST can reduce pain and alter cortical excitability, restoring its previous activity will occur from chronic pain.

Full description

Recent developments in the treatment of chronic pain have shown that the primary motor cortex (M1) is an effective target for neural brain stimulation techniques, such as transcranial magnetic stimulation (TMS). Due to these promising initial results, the plasticity of M1 has also been investigated as a potential marker for chronic pain. TMS studies using single or paired pulse shown changes in M1 plasticity in neuropathic pain and fibromyalgia pain compared to healthy subjects. Thus, there is a decrease in the inhibitory activity of chronic pain that can take a state as shown uninhibited by measuring TMS indexed intracortical inhibition (ICI) and cortical silent period (CSP). Based on these experimental data and clinical studies have been focused on the effects of neuromodulation techniques in M1 excitability. The techniques used to stimulate the peripheral nervous system was investigated using different approaches. The DIMST is a therapy applied to treat peripheral chronic syndromes that may have central components such as myofascial pain. During DIMST, the needles are applied to the spinal segment associated with nerve roots dermatome corresponding to the pathology. This treatment can also be effective in the treatment of diseases that have major peripheral components such as OA. OA is a major cause of suffering and disability in the elderly, having an inflammatory component, such as a factor that contributes to the symptoms and progression of the disease. There is evidence that OA could lead to sensitization central and segmental, but these effects on M1 plasticity and other central components are not completely known.

Therefore, researchers proposed to evaluate the plasticity of M1 in this chronic pain condition and also the effect of bottom-up DIMST in pain and cortical excitability.

Enrollment: 26 patients

Sex: Female

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Women with over 18 years old, with chronic pain because of primary osteoarthritis of the knee.
• Pain stable for at least three months. Score greater than or equal to 3 cm (0 cm = "no pain" and "worst possible pain" = 10cm) on VAS for pain perception at baseline.
• No contraindications to electro acupuncture or transcranial magnetic stimulation.
• Naive in acupuncture treatment.

Exclusion criteria

• Clinically significant or unstable disorder, medical or psychiatric.
• Presence of neurological or rheumatic comorbidity.
• Pregnancy.
• Having performed surgery in the knee to be treated in the last 6 months, or be planning surgery for the next semester.
• Having performed with corticosteroid infiltration in the last six weeks or are using this.
• Having performed with hyaluronic acid infiltration.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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26 participants in 2 patient groups

DIMST

Experimental group

Description:

The investigators used acupuncture needles with guide tubes (Suzhou Huanqiu Acupuncture Medical Appliance Co. Ltd., 218, China) that were 40 mm in length and 0.25 mm in diameter. The needling in DIMST was applied using an electro acupuncture device (Cosmotron, São Paulo, Brazil) in the dermatomes corresponding to the nerve roots involved in the knee (L1, L2, L3, L4, L5, S1, and S2). DIMST using was administered maintaining a distance from the spinous process line of 2 cm. The anatomic sites of peripheral DIMST were the muscles vastus medialis, rectus femoris, vastus lateralis, tibialis anterior; and the pes anserinus bursae. All subjects received one 30min session using a frequency of 2 Hz.

Treatment:

Procedure: DIMST

Placebo-sham

Sham Comparator group

Description:

The investigators used the same electro acupuncture device (Cosmotron, Sao Paulo, Brazil), which was previously set to prevent the current to pass through the electrodes. Subjects were informed that it would be a stimulus of low intensity and high frequency that they probably would not have any sense of it. The electrodes were placed on the same points where the active stimulation was applied while the nerve stimulation unit was left in front of the subject, for 30 minutes. This positioning ensured that the intermittent diode simulating the electrical stimulus was visible and audible.

Treatment:

Procedure: Placebo-sham