Overview

Picture this: you’re going about your day when suddenly, a throbbing pain erupts inside your head. You feel an immense wave of nausea wash over you as your vision is obstructed with bright flashes and blind spots. Light becomes too bright, and the sounds around you too loud. For over a billion people around the world, this isn’t just a scenario - it’s the reality of living with migraines.¹ 

If you or someone you know suffers from migraines, you're likely familiar with the challenge of finding effective pain relief. While painkillers or preventative medications are often the go-to, they don’t always work for all of us, and not everyone can use them. These medications treat the symptoms rather than what scientists believe to be the cause of migraine: abnormal brain activity. But what if there was a treatment that did address this root cause of migraine?² 

Harnessing the power of electromagnetic waves to target nerve cell activity in the brain, TMS offers a drug-free, non-invasive approach to not only relieving but potentially preventing your migraines. TMS appears to be a promising tool for numerous neurological disorders and mental illnesses, currently standing as a NICE-approved therapy for treatment-resistant depression. Could its use for migraine relief share the same trajectory? Read on to discover what the science so far has to say.^3,4,5,6 

Understanding Migraines

A migraine isn’t just a bad headache. It’s a complex condition characterised by a severe, recurring headache affecting one or both sides of the head, commonly accompanied by symptoms such as nausea and a heightened sensitivity to light (photophobia) and sound (phonophobia). It can last anywhere from hours to days. ^1,7,8 

Two major types exist, distinguished by the symptoms you experience before the attack:

• Migraine with aura: A migraine aura is a set of symptoms that serve as warning signs for the imminent onset of a migraine. Accordingly, they tend to take place before a migraine attack but may also be present during the episode, lasting around 30-60 minutes. These symptoms include:
  • Visual disturbances, e.g. flashes, flickers or arcs of light, seeing zig-zag patterns, temporary vision loss (blindspots or scotomas)
  • Changes in your sense of smell
  • Tinnitus
  • Increased sensitivity to touch (allodynia)
  • Tingling or numbness in the face and hands
  • Weakness on one side of the face or body
  • Difficulty speaking (dysphasia) 
  • Dizziness⁸ 

• Migraine without aura: This describes migraines that aren’t preceded or accompanied by the symptoms of aura, as experienced by the majority (75%) of people with migraines ⁷

Be sure to seek immediate medical attention if your migraine persists for more than 72 hours or if your aura lasts longer than one hour at a time.

Migraines can also be classified based on how often they occur.

• Episodic migraine: Headaches taking place for up to 14 days per month
• Chronic migraine: 15 or more headache days per month (8 of these having migraine symptoms) for at least three months.⁹ 

With its temporary disabling effects and the little predictability for when it might strike, it’s not hard to imagine the potentially life-altering impact of migraines. Although there are several other types of migraine, TMS aims to treat acute and chronic migraine both with and without aura.^2,3

What is transcranial magnetic stimulation (TMS)?

To better understand TMS, let’s break down the title. ‘Transcranial’ describes how and where the treatment is delivered; ‘trans-’ means across; ' cranial’ refers to the cranium (kray-nee-um) - the bones that form your head. The following term, magnetic, explains exactly what’s being delivered across your cranium: magnetic or electromagnetic waves. Finally, the noun ‘stimulation’ informs us of the purpose of the treatment - to activate nerve cells. But what do our nerve cells have to do with migraines? 

Nerve cells, also known as neurons, relay information between the body and the brain through electrical signals, allowing us to process and respond to incoming information from our surroundings (sensory stimuli). These neurons' activity level in the outer part of the brain (the cortex) is known as cortical excitability. If these neurons are overly active or ‘hyper-excitable’, they’re more likely to fire electrical signals for a given stimulus - a phenomenon known as cortical hyperexcitability. Think of your brain as a speaker and the world around you as a voice in a connected microphone. When your brain's excitability is heightened, the speaker’s volume dial is stuck on high, making everything much louder than usual.¹⁰ 

The increased brain activity can affect various functions, including perception, movement, and sensation. Although the biological origins of migraines aren’t completely understood, this abnormal brain activity is thought to be linked to its onset. ¹⁰ 

Therefore, TMS aims to regulate these neurons' activity via very small, painless electrical currents. This can be done either to reduce the severity of symptoms during an active episode of migraine with aura (single-pulse or sTMS) or to help prevent them from developing in the first place (repetitive or rTMS). While sTMS involves the delivery of single electromagnetic pulses, rTMS uses recurring pulses.^11,12  

How TMS works for migraines 

NICE guidelines and select NHS clinics offer useful information regarding what to expect from TMS for migraines. Although the exact process will vary from person to person, below is a general overview of what TMS treatment typically involves.

• To deliver the magnetic waves or pulses to the neurons in your brain, a tabletop or handheld TMS device is placed against the scalp.
• The electromagnetic coil is positioned where your pain is strongest (usually pre-determined by an MRI or EEG scan in a process called mapping).
• The device then releases painless pulses in short bursts (e.g. 10-20 seconds) with similarly short intervals (e.g. 30 seconds) in between - the strength, duration, pattern and timing in between these pulses are adjusted to your individual needs.

This is a safe and painless procedure. The only sensation you’re likely to feel is tapping on your head accompanied by a clicking sound as pulses are sent from the device to your brain - you’ll likely be given earplugs to avoid discomfort caused by the sound. Anaesthesia or numbing isn’t necessary; you’ll remain awake throughout the session, which normally takes anywhere between 20 minutes to just under an hour, including set-up time.

Since the effects of TMS are temporary, treatment typically occurs across several routine sessions, e.g. five times per week for around four to six weeks - although the treatment course will again vary depending on your specific situation. 

Effectiveness of TMS for migraine treatment

So far, scientific studies and reviews of this research have shown that TMS may help to lessen:

• Migraine frequency 
• Pain severity
• Headache symptoms 
• Episode duration 
• Medication use 
• The number of headache days^{4,5,6,13,14,15}

Notably, TMS appeared effective for migraines with or without aura and across different age groups in these studies and those previously conducted - all without inducing serious adverse effects. ^4,5,16 

However, it’s important to bear in mind that studies vary across stimulation parameters, like frequency and intensity, as well as in the delivery site of stimulation. As a result, there’s currently no set protocol for delivering TMS, meaning that the effectiveness of the treatment might vary across providers, as noted by NICE.

Therefore, despite these promising findings, NICE guidelines recognise that there's still a gap in scientific understanding of key areas, including: 

• The optimal procedure for delivering TMS, including a maintenance regimen
• How does it compare to drug treatment, or what drugs would work best alongside it
• Long-term effectiveness

Nonetheless, specialists agree that the straightforward TMS procedure is beneficial given the minimal training required, and people who’ve tried TMS report an overall very positive experience. An sTMS device gained CE approval in Europe for home use following its demonstration of both immediate (after 2 hours) and sustained pain relief (after 48 hours) without any serious side effects in a clinical trial of 164 people experiencing migraine with aura.¹³ 

Although NICE recommendations state that TMS isn’t a cure for migraines and may only provide moderate or mild relief for some, it serves as a generally safe alternative for people who:

• Can’t take medications, e.g. due to interactions with other medicines or existing medical conditions
• Would prefer to reduce their use of medications
• Don’t benefit enough from common treatment methods

Remember, it’s essential to talk to your doctor before making any changes to your medication habits and/ or if you’re considering TMS for your migraine pain so that they can advise on what’s likely to work best for your individual needs.

Safety and side effects of TMS

Common side effects during or after TMS sessions

With TMS relying on a harmless form of electromagnetic waves, the treatment hasn’t been associated with any serious side effects. As reported by NICE and The Walton Centre, some may experience mild to moderate symptoms, including:

• Slight dizziness
• Drowsiness 
• Tiredness or sleepiness
• Muscle tremors
• A tingling sensation (paraesthesia)
• Runny nose (rhinorrhea) or sinusitis 
• Sensitivity to sound after treatment 
• Scalp discomfort 

Some less common side effects are:

• Nausea 
• Worsening of original symptoms (e.g. headache or migraine-related visual loss)
• In very rare cases, an epileptic seizure¹⁷ 

These effects are temporary and don’t require medical attention, tending to lessen over subsequent sessions of TMS.

Precautions and considerations for TMS treatment 

Metal implants 

As TMS works via magnetic fields, you may be asked to remove all jewellery and metal from your body before your session. For the same reason, TMS may not be suitable for you if you have metal of any kind in your head (apart from dental fillings or braces). Examples include: 

• Metal plates
• Cochlear implants
• Cardiac pacemakers
• Stents 
• Brain or spinal cord stimulators
• Aneurysm clips or coils
• Facial tattoos using metallic/ magnetic ink¹⁸ 

Seizure risk

Although, as noted, the chances of a seizure happening due to TMS is rare (about 1 per 60,000 sessions), you might not be eligible for TMS if:

• You’ve experienced epileptic fits in the past
• You’re on a high dose of medication that increases your risk of fits
• You have an existing medical condition that makes you more susceptible to fits¹⁷

Pregnancy 

Although there isn't substantial direct evidence regarding the safety of TMS for pregnant women with migraines, it's considered safe for pregnant women undergoing treatment for depression.

This may come as welcome news to those of you struggling with pain relief while navigating pregnancy-related medication restrictions. Again, however, you must reach out to your doctor if you’re pregnant and considering TMS for your migraines to find out what’s best for you. ^16,19 

Availability and access to TMS treatment

Certain sTMS devices designed for home use are CE-marked in Europe, meaning that they meet the European Union's health, safety and environmental protection requirements. However, they’re currently only available in certain areas of the UK on the NHS and only for those who have been classed as eligible by specialist clinicians, i.e. headache specialists, as recommended by NICE. If you choose to purchase an sTMS device, you’ll still need a prescription from your headache specialist, who’ll assess whether this treatment suits you.

Summary

Through its drug-free and non-invasive approach to the targeted modulation of abnormal brain activity, TMS is a relatively convenient alternative or supportive treatment option for both the alleviation and prevention of migraines. While TMS may not be suitable for everyone, and further research into its effectiveness is ongoing, its ease of use and minimal side effects make it a valuable addition to the migraine treatment landscape. With the guidance of your specialist doctor, TMS represents a promising step towards reclaiming migraine-free days and embracing your daily life to the fullest.