JNNP: The greater occipital nerve blocks the pain signals in the trigeminal nerve and cervical spinal complex

Drug blockade of the greater occipital nerve (GON) has been shown to be effective for cluster headache, trigeminal neuralgia, and may be effective for migraine
.
But the evidence for migraine is still not so conclusive, because one of the placebo-controlled studies was negative

Most of the trigeminal nerve and occipital lobe pain signals share the same neurons in TCC, so TCC is the interaction site responsible for the clinical efficacy of GON blocking
.
Therefore, this article began to study this interaction in healthy volunteers, exploring the impact of GON block on detection and pain threshold, through quantitative sensory testing (QST) and thermal trigeminal nerve stimulation, and using functional magnetic resonance technology to measure blood indirectly The oxygenation level of brainstem neuron activity changes caused by the stimulation depends on the signal

QST test location description

This study is a randomized, placebo-controlled, double-blind crossover study

Response of the spinal trigeminal nucleus to painful stimuli

When comparing the interventions with lidocaine and placebo, the CDL and thermal detection limits of each trigeminal nerve branch and the QST of cold pain threshold and warm thermal pain threshold showed no significant difference (p>0.
05)

The interaction between the trigeminal nerve and the occipital lobe input in the TCC may occur at the C2 level.
The painful signal converges on the same nucleus, passes through the contralateral side, and then is transmitted to a higher processing center
.
The application of lidocaine-GON block may reduce neuronal input from the occipital nerve and affect the summary of neuronal activity transmitted to higher processing centers without affecting the peripheral trigeminal nerve itself

HoffmannJ ,MehnertJ ,KooEM , et alGreater occipital nerve block modulates nociceptive signals within the trigeminocervical complex Journal of Neurology, Neurosurgery & Psychiatry