The role of left prefrontal transcranial magnetic stimulation in episodic migraine prophylaxis

DOI: https://doi.org/10.1186/s41983-019-0140-5

Abstract-Summary The aim of the study was to examine the prophylactic role of repetitive transcranial magnetic stimulation (rTMS) on the frequency, and severity of migraine attacks in episodic migraineurs who failed medical treatment.

The primary outcome measure was the achievement of 50% reduction in the

number of migraine attacks.

The study revealed that 69.2% of the active treatment group achieved 50% or more reduction in the number of migraine attacks versus 25% of cases in the control group (p = 0.02).

The absolute number of migraine attacks was reduced by 3.1 vs 1.5 in the active

and control group, respectively.

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The number of cases with severe HIT-6 scores was reduced by 46.2% in active

treatment group versus a 7.1% reduction in the control group (p = 0.02).

High-frequency rTMS applied to LDLPFC can reduce the number of migraine attacks by 50% or more in almost 70% of a sample of episodic migraineurs with a concomitant decrease in functional disability.

Extended: The primary outcome measure was defined as the reduction of

migraine attack frequency by at least 50% after rTMS sessions.

The number of patients with severe HIT-6 score (60 or more) was reduced by 46.2% (6/13 cases) in the active treatment group and by only 7.1% (1/14 cases) in the control group (p = 0.02).

High-frequency rTMS applied over the LDLPFC was used by Brighina et al. in

an open-label sham-controlled study (n = 12) that recruited chronic migraineurs.

Introduction Migraine is classified into an episodic and a chronic form based on the frequency of migraine attacks per month.

Episodic migraine, which is considered as the milder form, has an annual conver-

sion rate of 2.5% to chronic migraine [22].

Most of the work done on the prophylactic role of rTMS targeted chronic migraineurs with conflicting results, apart from one study that recruited episodic and chronic migraineurs and reported positive results [477–489]

In an effort towards resolving this conflict and clarifying the best responders to

rTMS, we decided to work only on cases with episodic migraine.

This placebo-controlled pilot study examined the prophylactic role of LDLPFC

high-frequency rTMS in a group of episodic migraineurs.

Methods They were not involved in patient assessments, follow-up, or data analysis.

Four patients dropped out during the treatment phase and follow-up (three from the control group and one from the active treatment group) due to lack of response and travel.

The active treatment group received 5 rTMS sessions, delivered over one week. Each rTMS session consisted of a single train of 900 total pulses over 3  min

duration given at 5-Hz frequency and 100% motor threshold intensity.

There was no change in the treatments received by the patients for 2  months

before active enrollment and during the study period.

Patients were followed up for one month before receiving rTMS, and for another

month after the sessions by a headache diary.

The primary outcome measure was defined as the reduction of migraine attack

frequency by at least 50% after rTMS sessions.

Results Regarding the inter-group comparisons, a 50% reduction in migraine attacks and migraine days was achieved in 69.2% (9/13 cases) of the active treatment group versus a 25% (4/16) (p = 0.02) and 31.2% reduction (5/16) (p = 0.048) in the control group in both outcome measures, respectively.

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A clinically significant decrease in disability as measured by a 5 points reduction in HIT-6 score was achieved in 84.6% (11/13) of active cases vs 50% 8/16 of con- trols (p = 0.058).

The absolute HIT-6 score reduction was 15.3(13.1) vs 6.1(5.2) in the active and

control groups, respectively.

The number of patients with severe HIT-6 score (60 or more) was reduced by 46.2% (6/13 cases) in the active treatment group and by only 7.1% (1/14 cases) in the control group (p = 0.02).

Discussion The 6 cases in the active group achieved a significant reduction of migraine attacks (> 50%) [489].

Another study recruited 14 chronic migraine cases, who received 23 rTMS ses- sions over the LDLPFC on alternate days failed to show a significant improvement in the active treatment group [477].

Their results showed a 50% reduction of migraine days in 65–70% of cases in

both treatment groups in the first month after therapy [490].

Our study showed a reduction of 50% or more in migraine frequency and

migraine days in almost 70% of the active treatment group.

More work is needed at the bench side to better understand the correlation between the observed changes in neurotransmitter and neural activation studies in healthy and migraine cases, the clinical phenomenology of migraine, the rTMS stimulation parameters, and the clinical response to rTMS.

Acknowledgement A machine generated summary based on the work of Amin, Randa; Emara, Tamer; Ashour, Samia; Hemeda, Mahmoud; Salah Eldin, Nahed; Hamed, Salma; Shouman, Sara; Shouman, Mohamed. 2020 in The Egyptian Journal of Neurology, Psychiatry and Neurosurgery.

Occipital Nerve Stimulation in Chronic Migraine: The Relationship Between Perceived Sensory Quality, Perceived Sensory Location, and Clinical Efficacy—A Prospective, Observational, Non-Interventional Study