Introduction

Migraine is a common health condition affecting millions of people around the globe. People with migraine can either have the chronic or episodic form of the condition. Some individuals endure less frequent forms of headaches, while others suffer more consistent forms of chronic migraine. This article will help you to understand the differences between the two, the symptoms, diagnosis, and treatment to get you the help you need to manage the symptoms. So let's dive straight into the article, say goodbye to the throbbing pain and hello to a life of freedom and comfort.

Importance of understanding the differences between episodic and chronic migraines 

To understand the difference between the two, it's essential to first understand what migraine is. A migraine is a very bad headache usually occurring with a throbbing pain on one side of the head. Migraines can be episodic or chronic. An episodic migraine is recurrent but less frequent, occurring on less than 15 days in a month, whereas chronic migraine occurs for more than 15 days per month with more severe symptoms.

Purpose and scope of the article

The main purpose of the article is to inform individuals dealing with this condition to understand the difference between episodic and chronic migraine and to recognise the signs and symptoms, duration, frequency, diagnosis, and effective treatment plans, as well as to raise awareness about this condition. 

Definitions and diagnostic criteria

Episodic migraine 

Episodic migraine is diagnosed in individuals who have 0 to 14 days of headache per month¹. Its symptoms can range from mild to severe. Individuals with episodic migraines may experience remission, maintain their current condition, or progress to high-frequency episodic or chronic migraines over time.² Episodic migraine can be disruptive but its symptoms are manageable by taking medication and making some lifestyle adjustments. 

Diagnostic criteria 

Diagnosing migraines involves several steps as there's no single test for it. Doctors will ask about the severity of symptoms, how often they occur how long, and any triggers you may have noticed. They'll also check if you have a family history of migraines or other medical conditions. A physical examination, blood tests, and possibly an MRI or CT scan may be done to rule out other issues.

Chronic migraine 

Chronic migraine is a common daily headache accompanied by frequent headache attacks with at least 15 or more days of headache per month.³ The quality of life is significantly reduced in individuals with this condition, and comorbidities are much more common compared to episodic migraine.⁴

Diagnostic criteria 

Diagnosing chronic migraines requires a detailed patient interview and neurological examination. Sometimes, additional tests are required to rule out other types of long-term headaches and secondary headache disorders.⁵

Frequency and duration of episodic and chronic migraine

Episodic migraine (EM) means having up to and including 14 headache days per month, whereas chronic migraine (CM) means having 15 or more headache days per month. 

CM is specifically defined as having headaches for at least 15 days a month for 3 months, with 8 of those days being migraines that either aren’t accompanied by an aura or don’t respond to migraine treatments. 

EM and CM are connected in a complicated way. About 2.5% of people with EM develop CM each year, and about 26% of those with CM can revert back to having EM over 2 years.¹

Symptoms and severity

On average, individuals with chronic migraine (CM) experience longer duration of headache attacks compared to those with episodic migraine (EM), even when treated. Furthermore, chronic migraine patients are more prone to experiencing severe painful symptoms than episodic migraine sufferers.¹

Migraine can affect individuals of all ages, including children, teenagers, and adults, and typically progresses through four stages: 

• Prodrome
• Aura 
• Attack
• Post-drome

Not everyone experiences all these stages of a migraine.

During the prodrome stage, which occurs one or two days before a migraine, individuals may notice some subtle changes that signal an ongoing migraine, such as: 

• Constipation
• Mood swings
• Food cravings
• Neck stiffness
• Increased urination
• Fluid retention
• Frequent yawning.

Some individuals may experience an aura before or during migraines. Auras are often visual but can also involve other disturbances, with symptoms gradually developing over several minutes and lasting up to an hour. Examples of migraine auras include:

• Visual disturbances
• Vision loss
• Pins and needles sensations
• Weakness or numbness in the face or body
• Difficulty speaking.

The attack phase of migraine typically lasts between 4 to 72 hours if left untreated, with frequency varying from person to person. Symptoms during a migraine attack may include: 

• Throbbing pain in the head, on one or both sides
• Sensitivity to light, sound, smell, and touch
• Nausea and vomiting

Following a migraine attack, individuals may experience a postdrome phase where they may feel drained, confused, or washed out for up to a day. Some individuals may report feeling disturbed, and sudden head movements could trigger pain again.

Triggers and risk factors

Research findings and clinical observations indicate a transformation from episodic migraine (EM) to chronic migraine (CM). Approximately 2.5% of individuals with EM transition to CM each year. Since not all individuals with EM progress to CM, it is important to identify those who are at high risk for this transition. 

Risk factors can be divided into those that can be easily changed (modifiable) and those that are not modifiable. Examples of non-modifiable risk factors include:

• Age
• Gender
• Race
• Education level/socioeconomic status
• Prior head injury

Recognising modifiable risk factors for the progress to CM, such as: 

• Obesity
• Depression
• Medication overuse 

is crucial. Below are brief discussions on potential modifiable risk factors and their connections to the transition from EM to CM.

Obesity is linked to frequent headaches and can increase the risk of episodic migraines (EM) progressing to chronic migraines (CM). 

Depression, anxiety, and chronic pain disorders are more commonly associated with CM than EM. Stressful life events such as divorce, job changes, or problems with children are linked to chronic daily headaches. Research shows that those with chronic daily headaches often had major life changes or accidents in the year before or the same year their headaches started.

Overuse of acute medications is a high-risk factor for poor migraine diagnosis.

High caffeine consumption modestly increases the risk of developing chronic headaches, most notably in women, and individuals under 40.¹

Impact on quality of life

Migraines and other headaches can significantly impact a person's ability to work, leading to decreased productivity and strained interpersonal relationships. Many individuals continue to work despite debilitating and painful symptoms, which can affect their work performance and productivity, finances, relationships, and mental health. This productivity loss also results in economic losses for companies and the economy as a whole.

Treatment and management

There are two main treatment approaches for chronic and episodic migraine:

• Acute treatment, and
• Preventive treatment

Acute treatment

Migraine attacks often require acute medication due to their severe and disabling nature, which is usually accompanied by symptoms such as sensitivity to light and sound. The main difference between chronic migraine (CM) and episodic migraine (EM) is the frequency of headache days, not the specific symptoms. 

Both CM and EM patients use acute treatments such as:

• Analgesics (pain relief)
• NSAIDs (non-steroidal anti-inflammatory drugs: pain relief, such as ibuprofen)
• Migraine-specific medications, such as triptans and ergot derivatives

It's important to treat symptoms as early as possible in both CM and EM patients, although those with CM often respond less effectively to triptans. Additionally, overusing medications that contain barbiturates and opiates is a significant concern, especially for CM patients due to the risk of developing dependence on these medications. It's important to monitor and limit the use of these drugs and educate patients on the risks of medication overuse and the potential progression to CM.¹

Preventive treatment

Several drug classes are used to prevent migraines, including: 

• Antihypertensives (β-blockers, ACE inhibitors)
• Antiepileptics (topiramate, valproate)
• Antidepressants (tricyclics)

While these are effective for episodic migraines (EM), only topiramate has shown efficacy for chronic migraines (CM) in clinical trials. 

Onabotulinumtoxin-A injections are more effective for CM, but not for EM. Other 

less-studied options for CM include: 

• Gabapentin
• Pregabalin
• Fluoxetine
• Tizanidine, zonisamide, and memantine¹

FAQ’s

What is the main difference between episodic and chronic migraine?

The main difference is that episodic migraine occurs for up to and including 14 days in a month, whereas chronic migraine can occur for 15 or more days per month.

What causes episodic migraine to turn into chronic migraine?

The main risk factors for progression from episodic to chronic migraine are overuse of medication, high levels of stress, sleep disturbances, obesity, caffeine intake, and other comorbidities such as depression and anxiety.

Are the symptoms different for chronic and episodic migraine?

The symptoms are the same for both, including common symptoms such as nausea, vomiting, and sensitivity to light. The main difference between chronic and episodic migraine is the frequency of headaches.

Can lifestyle changes help to manage both chronic and episodic migraines?

Yes, lifestyle changes can help manage the severity of symptoms. Ensuring adequate sleep, avoiding stress, and avoiding known triggers can help manage both.

Can chronic migraine revert back to episodic?

Yes, with effective treatment and some lifestyle changes chronic migraine can revert back to episodic migraine.

What should I do if I think I have chronic migraine?

You can consult with your healthcare provider and let them know your symptoms. With proper diagnosis and treatment, you may be able to lead a headache-free life. 

Summary

Migraine, a painful headache, is just like an unwelcome storm that can disrupt your day, leaving you in agony and pain and turning a good day upside down. It is known that episodic migraine can transform into chronic if not taken seriously, but there are treatments that can be used to allow you to live a headache-free life. Our healthcare providers can use behavioural and medication-based interventions to help patients maintain a healthy lifestyle and lower the risk of developing chronic migraines (CM).