What Is a Confusional Migraine?

A confusional migraine, also known as an acute confusional migraine (ACM), is a rare type of migraine that primarily affects children and teenagers. Approximately 10 percent of school-aged children have migraines. Of this group, one in six have migraines that classify as an ACM. Researchers have noted that ACMs may be underdiagnosed, so this number may be higher.

Non-ACM migraines, in contrast, are surprisingly common. About 12 in every 100 people in the United States have non-ACM migraines.

Although migraines have been studied for many years, ACMs are still in the early stage of medical research. Only a small number of case studies can be found in medical literature. Several researchers have recommended that ACMs be added to the official International Classification of Headache Disorders as a “migraine variant.” This may help pediatricians and others more easily recognize this type of migraine.

What Are the Symptoms of an ACM?

ACMs take their name from their main symptom, which is a state of intense confusion that occurs suddenly and lasts longer than the headache. The average episode is approximately five hours. Generally speaking, an episode can be as short as 30 minutes or as long as 24 hours.

During an ACM, you may experience symptoms that include:

  • a headache
  • memory loss
  • anxiety
  • agitation
  • blurred vision
  • dizziness
  • speech impairment
  • disorientation, or a loss of a sense of place and time

Episodes are often followed by a period of deep sleep and recovery. Afterward, you may not remember what occurred, although you’re alert as it’s happening. The symptoms fade after the episode.

Read more: Severe and acute migraines: Coping with vertigo and nausea »

What Are the Causes of an ACM?

It isn’t clear what causes an ACM, and research about what might trigger this is ongoing. More ACM cases are being studied with neuroimaging. One possible cause is a bump on the head, which is reported in about 40 percent of ACMs. Emotional stress and strenuous exercise have also been suggested as triggers. In contrast, triggers for other types of migraine have been well-documented. Common migraine triggers are:

  • environmental factors, such as odors, noise, bright lights
  • food or drinks, such as salty foods or wine
  • psychological factors, such as increased stress
  • physiological factors, such as exercise that provokes migraine activity in the brain

Read more: Migraine triggers and how to avoid them »

Who Is at Risk?

Having a family history of migraine attacks is the leading risk factor for ACM. About four out of five people who have migraines also have a family history of migraines. If one of your parents had migraines, you have a 50 percent chance of developing them. If both of your parents had migraines, your chance of having them increases to 75 percent.

You may also be at risk if you experience other types of migraines. About 50 percent of ACMs occur in people who’ve previously had one or more episodes of the more prevalent types of migraines.

How Is an ACM Diagnosed?

A doctor often must first eliminate the possibility of other conditions that show similar symptoms. Doctors may rule out epileptic seizures, stroke, and encephalitis before coming to an ACM diagnosis. Transient global amnesia syndrome must also be ruled out in adults.

According to a 2012 review of ACMs, doctors should consider screening for electrolytes, glucose levels, and drugs. If you don’t have a history of migraines, your doctor may order imaging tests such as an MRI or CT scan of your brain. If they suspect you have an infection, they may recommend a spinal tap.

Your doctor may also use the length of your episode and the symptoms present to rule out any other conditions. It’s important that your doctor considers your personal health history and your family’s medical history.

How Is an ACM Treated?

You should seek immediate medical care if you’re having symptoms of an ACM. Your doctor will determine what exactly is causing these symptoms and whether they’re the result of an ACM or another underlying condition.

Case studies have shown that ACMs can be treated with medications used for common migraines, as well as other drugs. This can include:

  • over-the-counter painkillers
  • topiramate (Topamax)
  • intravenous (IV) valproic acid
  • IV prochlorperazine
  • high-flow oxygen therapy

What to Expect After an ACM Episode

Episodes usually don't last long. The average episode lasts five hours. All symptoms are resolved after the episode, and you probably won’t have any memory of the event.

About one in four people who experience an ACM will have one or more subsequent episodes. More commonly, future migraine episodes will be of the non-ACM variety. Non-ACM migraines have specific triggers and a known pattern of development.

A doctor may prescribe medication to help prevent you future ACM or non-ACM migraines. Medication may also be used to lessen migraine severity.

Can You Prevent Further ACM Episodes?

Because the triggers of ACMS aren’t fully known, there aren’t specific guidelines for preventing new ACM episodes. Researchers have reported a small number of cases in which sodium valproic acid and intravenous valproic acid successfully eased an ACM episode and deterred further episodes. Valproic acid reduces brain excitability, which is thought to be a factor in migraine susceptibility.

If you have further attacks of any non-ACM migraines, there are some things that you can do. Keeping a log or journal is a first step to help manage migraines. You should keep a record of:

  • when your migraines tend to occur
  • what precedes your migraines
  • how long the migraines last
  • what symptoms you experience
  • what helps alleviate the pain

You and your doctor can use this information to develop an individualized treatment plan.

In addition to avoiding or limiting interaction with your known triggers, you can also take pain medication as soon as you suspect a migraine is about to occur.

You may also be interested in joining a migraine support group online or in person to see how others cope with migraines.