Clinical observation of the effect of prophylaxis on allodynia in patients with migraine

Ultrasound-Guided Combined Greater Occipital Nerve Block at the C2 Level with Trapezius Trigger Point Injection and Supraorbital-Supratrochlear Nerve Block: More Effective on Allodynia and Disability in Chronic Migraine

Background

Chronic migraine (CM) patients with cutaneous allodynia (CA) show a poor response to treatment. Long-term studies have yet to be conducted to demonstrate the efficacy of blocks on CA. This study evaluated the improvement in allodynia and disability in CM treated with ultrasound (US)-guided blocks.

Methods

In this prospective, non-randomized comparative study, 60 CM patients with CA were evaluated for the clinical effectiveness of the therapy using the numeric rating scale (NRS), headache impact test-6 (HIT-6), brush allodynia test, and allodynia symptom checklist (ASC-12). At the first visit, tenderness in the nerve or trapezius muscle was confirmed in the intervention group. US-guided greater occipital nerve block (GONB), GONB, and trapezius muscle injection (TPI), or GONB, TPI, and peripheral trigeminal nerve block (PTNB), respectively, were performed four times once a week for a month. Initial and third-month assessments were performed.

Results

The ASC-12 scores decreased in the GONB+TPI+PTNB and GONB groups more than the GONB+TPI group (mean rank, respectively, 26.86, 27.40, 38.39; P = 0.018). The decrease in HIT-6 scores was greater in the GONB+TPI+PTNB group than in the GONB group (mean rank, respectively, 21.98, 39.95, P < 0.017) in the first month. In the third month, the GONB+TPI+PTNB group scored HIT-6 significantly lower than GONB and GONB+TPI (mean rank: 18.84, 38.73, 35.61; P < 0.001).

Conclusions

GONB+TPI+PTNB was more successful in alleviating allodynia and disability.

Is Allodynia a Determinant Factor in the Effectiveness of Transcranial Direct Current Stimulation in the Prophylaxis of Migraine?

OBJECTIVES

Allodynia, the clinical marker of central sensitization, affects even simple daily living activities and increases the tendency for migraine to be more resistant to treatment and have a chronic course. Migraine that impairs quality of life can often be treated with variable pharmaceutical agents, but with various side effects. Transcranial direct current stimulation (tDCS) is a potential alternative treatment for migraine prophylaxis.

MATERIALS AND METHODS

Seventy-seven patients diagnosed with migraine (48 with allodynia and 29 without allodynia) were included in the study. Randomly, 41 of the 77 patients received sham stimulation and 36 patients underwent three sessions of anodal left primary motor cortex stimulation for 2 mA, 20 min. Migraine attack characteristics (frequency, severity, and duration) and analgesic drug use were followed with headache diaries for one month after the stimulation.

RESULTS

After tDCS, migraine attack frequency (p = 0.021), the number of headache days (p = 0.005), duration of attacks (p = 0.008), and symptomatic analgesic drug use (p = 0.007) decreased in patients receiving active tDCS, compared to the sham group. The therapeutic gain of tDCS was calculated as 44% (95% confidence interval [CI]: 22-60%) for headache days and 76% (95% CI: 55-86) for headache duration. Response to tDCS treatment was higher in patients without allodynia (60% vs. 24%; p = 0.028) and allodynia came out as an independent predictor of response to tDCS with logistic regression analysis. Side effects were rare and similar to the sham group.

CONCLUSIONS

tDCS is a safe, efficacious, and fast method for migraine prophylaxis. However, the administration of tDCS before allodynia occurs, that is, before central sensitization develops, will provide increased responsiveness to the treatment.

SIGNIFICANCE

tDCS is more effective before the development of allodynia, but it also improves the quality of life even after the development of allodynia.

Prevalence and characteristics of cutaneous allodynia in probable migraine

Cutaneous allodynia (CA) is a pain in response to non-nociceptive stimulation and a marker of central sensitisation. Probable migraine (PM) is a migraine subtype that fulfils all but one criterion of migraine. Headache intensity and the disability of individuals with PM are similar or lower than individuals with migraine. This study compared CA prevalence and characteristics of PM and migraine using a nationally representative sample in Korea. The Allodynia Symptom Checklist-12 (ASC-12) was used to assess CA (ASC-12 score ≥ 3). PM and migraine prevalence were 11.6% and 5.0%, respectively. CA prevalence did not significantly differ between PM and migraine (14.5% vs. 16.0%, p = 0.701). Participants with PM with CA reported a higher monthly headache frequency (3.3 ± 4.3 vs. 1.8 ± 3.6, p = 0.044), more severe headache intensity (Visuals Analogue Scale, 6.0 [4.0–7.0] vs. 5.0 [3.0–6.0], p = 0.002), and higher impact of headache (Headache Impact Test-6, 56.3 ± 7.2 vs. 48.3 ± 8.0, p < 0.001) than those without CA. Multiple regression analyses revealed that headache frequency and intensity, anxiety, and depression were significant factors for CA in participants with PM. In conclusion, CA prevalence among participants with PM and migraine were comparable. Anxiety, depression, and headache frequency and intensity were significant factors for CA in participants with PM.