Morphometric changes over the whole brain in caffeine-containing combination-analgesic-overuse headache

Area of Science:

• Neuroimaging
• Neurology
• Neuroscience

Background:

• Medication-overuse headache (MOH) is a prevalent condition often treated with combination analgesics containing caffeine.
• Excessive caffeine intake in analgesics is suspected to contribute to MOH pathogenesis, but underlying brain changes are not fully understood.

Purpose of the Study:

• To investigate brain morphometric alterations in patients with MOH associated with excessive consumption of caffeine-containing combination analgesics.
• To identify specific brain regions affected and correlate these changes with clinical variables such as headache frequency and duration.

Main Methods:

• Magnetic resonance imaging (MRI) T1-weighted images were acquired from 32 MOH patients overusing caffeine analgesics and 26 matched controls.
• Automatic volume algorithms were used to analyze brain region volumes across the whole brain using a neuromorphometrics template.

Main Results:

• MOH patients showed reduced volumes in the cerebellum and optic chiasm.
• Increased volumes were observed in the right lateral orbital gyrus, left calcarine, bilateral middle occipital gyrus, right superior parietal lobe, and right temporal transverse gyrus.
• Volume increases were more pronounced in patients with lower headache frequency (10-20 days/month) and without psychological comorbidities.

Conclusions:

• Brain morphometric changes in areas related to emotion, cognition, vision, and pain processing suggest their involvement in the development of MOH from caffeine-containing analgesic overuse.
• Specific volume changes in visual processing areas and volume gain in patients with less severe headache and fewer comorbidities may characterize MOH related to caffeine analgesic overuse.