Chapter 13: Migraine Equivalent or Episodic Syndromes in Children

INTRODUCTION

In recent years, the polygenic nature of migraine has been explored, and up to 39 genes have been associated with migraine.¹ These genes are widely expressed in the entire body and affect all major systems. As a result, children who are diagnosed with migraine in later years may present with different phenotypes in younger years. The 2018 International Classification of Headache Disorders, Third Edition (ICHD-3) guidelines described these different phenotypes as migraine equivalent or episodic syndromes associated with migraine.² According to one survey, up to 40% of children diagnosed with episodic syndromes will develop migraine as adults. Types of migraine equivalent or episodic syndromes include the following:

• Infant colic

• Benign paroxysmal torticollis

• Benign paroxysmal vertigo

• Alternating hemiplegia of childhood

• Cyclic vomiting syndrome

• Abdominal migraine

These types are discussed in the following sections.

INFANT COLIC

Before more complex communication skills are developed in infants, crying may be the most important communication skill and may have survival benefits, but inconsolable crying may be a challenging experience for caregivers and may have a secondary cause. According to ICHD-3, infant colic is defined as “recurrent episodes of irritability, fussing or crying from birth to 4 months of age with episodes lasting > 3 hours/day, episodes > 3/days in a week for over 3 weeks, in otherwise healthy infant.”²

Parents with migraine have a 5-fold risk of having a baby with infant colic, which supports the strong genetic basis of migraine. The pathophysiology of infant colic is not clear, but it is hypothesized that gastrointestinal (GI) inflammation, change in gut bacteria, or feeding techniques may cause GI distress in those who are genetically predisposed.³ No study has definitively identified the etiologic basis of infant colic. The most important thing to consider is that diagnosis of infant colic requires exclusion of other causes of inconsolable crying. Because risk of shaken baby syndrome is associated with age-related crying, identifying cases of infant colic may help to identify high-risk infants.⁴

BENIGN PAROXYSMAL TORTICOLLIS

The ability of an infant to hold their neck in the first 3 to 4 months of life is considered an important milestone. It helps an infant to observe their surroundings and interact with others and may aid in their posture. According to ICHD-3, benign paroxysmal torticollis is defined as:

• Recurrent episodes of head tilt to either side within the first year of life (most commonly after ability to hold neck) with spontaneous remission in an otherwise healthy infant

• Each episode may last for minutes to days

• These attacks may be associated with any of the following symptoms:

  • Pallor

  • Irritability

  • Malaise

  • Vomiting

  • Ataxia

Historically, nystagmus may be associated with this condition, but it is not ...