Cluster Analysis of Migraine-Associated Symptoms (CAMS) across the lifespan: a cross-sectional study

Headache-associated symptoms (e.g., sensory sensitivity, nausea) are used to classify primary headache disorders and define treatment outcomes. We developed Cluster Analysis of Migraine-Associated Symptoms (CAMS) to provide an aggregate measure that captures relationships between several headache-associated symptoms. CAMS reveals that a greater number of symptoms, particularly if they include symptoms of autonomic and vestibular dysfunction, are associated with older age and greater headache burden in children and adolescents. Here, we aim to determine if CAMS is generalizable to adults.

The Penn Online Evaluation of Migraine (POEM) survey collected headache characteristics on participants ([Formula: see text]18 years) who reported headache. CAMS models were generated based on the presence or absence of 12 headache-associated symptoms. Three models were compared: the original CAMS model developed for children and adolescents, a model generated with adult data, and a comparison pediatric model for data collected across the same timeframe as the adult data. Changes in CAMS as a function of age and headache burden were measured.

CAMS generated from the adult (n = 350) and pediatric comparison (n = 471) datasets were consistent with the original CAMS model (n = 6,662). Across models, the first dimension (CAMS 1; 25.4-31.0% explained variance) represented the absence or abundance of symptoms; the second dimension (CAMS 2; 10.8-11.6% explained variance) separated the typical symptoms of migraine (photophobia, phonophobia, nausea/vomiting) and osmophobia, from vestibular symptoms (vertigo, imbalance, lightheadedness, tinnitus, diplopia). CAMS symptom number increased throughout childhood and adolescence, reaching a plateau in early adulthood. A greater number of symptoms and more autonomic and vestibular symptoms were associated with greater headache burden and allodynia.

CAMS is generalizable across the lifespan, providing a reliable outcome measure that aggregates information about many headache-associated symptoms. Greater symptom number that includes vestibular symptoms is associated with increased headache burden and allodynia.