Central Sensitisation

medicine

Definition

Central Sensitisation

Central sensitisation is the amplification of neuronal signalling within the central nervous system that elicits pain hypersensitivity.

In migraine, once established within the thalamus and higher cortical centres, peripheral interventions such as triptans become largely ineffective.

Mechanism

Progression from peripheral to central

Early in a migraine attack, pain signals originate from trigeminal nerve terminals and meningeal nociceptors. If the attack is not aborted promptly, sustained nociceptive input causes functional changes in the spinal trigeminal nucleus and thalamus.

This lowers the firing threshold of central neurons and expands receptive fields.

Clinical Manifestations

Cutaneous allodynia

The most reliable clinical marker is cutaneous allodynia, in which normally non-painful stimuli become painful.

Other signs include prolonged headache duration, resistance to acute medication, and a perceived paradoxical worsening after taking a drug that acts only peripherally.

Therapeutic Implication

Triptan timing

Triptans are effective only when administered early, before central sensitisation is established. Once central pathways dominate, gepants, ditans, or non-pharmacological interventions are preferred.