Overview and Definition

Abdominal migraine (AM) is a debilitating condition characterized by paroxysmal (sudden, recurring) episodes of abdominal pain accompanied by vasomotor symptoms (changes in blood vessel function causing pallor, flushing, or temperature changes), leading to a significant reduction in quality of life. While more commonly observed in children, AM is increasingly recognized in adults, though it remains rare and less well understood in this population.

Epidemiology

The prevalence and clinical outcomes of AM in adults are unclear due to limited and conflicting literature. Among children with recurrent abdominal pain, the estimated prevalence of AM ranges from 2.4% to 4.1%, with a mean age of onset of around seven years.

A longitudinal study from the UK that followed 54 children diagnosed with AM found that the condition resolved in approximately 61% of participants over an 8-10-year period. However, a significant proportion continued to experience recurrent abdominal pain during migraine attacks into adulthood.

Pathophysiology

Although the exact pathophysiology (how the disease works in the body) of AM is unclear, several contributing mechanisms have been proposed, including visceral hypersensitivity (increased sensitivity of internal organs), altered gut motility (abnormal movement of the digestive tract) - now referred to as "Disorders of Gut-Brain Interaction" - and psychological factors that influence the hypothalamic-pituitary-adrenal axis (the body's stress response system).

Additionally, it is hypothesized that AM shares pathophysiological mechanisms with traditional migraine. Activation of the trigeminovascular system can lead to neurogenic inflammation and the release of proinflammatory peptides such as substance P, vasoactive intestinal peptide (VIP), and calcitonin gene-related peptide (CGRP).

Pediatric Presentation

Abdominal migraine is characterized by recurrent episodes of abdominal pain in an otherwise healthy child who is normal between attacks. The pain is typically midline or poorly localized, moderate to severe in intensity, and associated with at least two additional features such as anorexia, nausea, vomiting, or pallor.

Headache is not a prominent feature during attacks and may be overlooked if the child is not asked about it. Photophobia or phonophobia are uncommon. Most children stop having attacks by early adolescence, but rarely attacks may persist into adulthood.

Adult Presentation

Adult patients with AM often experience symptoms similar to those observed in children, particularly episodes of chronic abdominal pain. A distinguishing characteristic of AM is its paroxysmal (sudden, episodic) nature, which sets it apart from many other gastrointestinal disorders that typically present with chronic, more frequent symptoms.

AM also shares clinical features with several adult-onset conditions, including cyclic vomiting syndrome (CVS), irritable bowel syndrome (IBS), cannabinoid hyperemesis syndrome, narcotic bowel syndrome, functional dyspepsia (FD - chronic indigestion), and centrally mediated abdominal pain syndrome (CAPS - chronic widespread abdominal pain).

Diagnostic Criteria

Currently, there are no established guidelines for diagnosing or managing AM in adults. Diagnosis should be based on a thorough medical history, physical examination, and appropriate investigations. AM is a diagnosis of exclusion.

Differential Diagnosis

The many causes of acute abdominal pain need to be considered in the differential diagnosis. Testing is determined by the history and physical examination, but the search for a mechanical process such as obstruction, kidney disorder, infection, or metabolic condition may be necessary.

Patient history should exclude "alarm symptoms" such as unexplained weight loss, melena (black, tarry stools indicating bleeding), rectal bleeding, or altered bowel habits, which may indicate more serious underlying pathology requiring further invasive investigations.

Management and Treatment

The approach to treatment depends on the patient's age, symptom severity, and individual response to therapy. Patient education and reassurance are central to management and represent the first-line treatment.

Diet modification appears to play a significant role in managing AM in children, with up to 93% reporting at least one food type that worsens their gastrointestinal symptoms. However, the effectiveness of these dietary interventions in adults with AM remains unclear.

Prognosis and Long-term Outcomes

Most children with abdominal migraine evolve to develop migraine headaches. In one study of 54 children with abdominal migraine who were followed for 7 to 10 years, current or previous migraine headache was identified in 70 percent.

The true prevalence of AM in adults remains uncertain due to frequent misdiagnosis and underdiagnosis. Many adult patients undergo extensive investigations and multiple consultations before receiving an accurate diagnosis.

References