An unusual diagnostic route: Pediatric case of a mesencephalic cavernoma presenting as cluster headache

Cluster headaches are characterized by painful unilateral periorbital attacks accompanied by dysautonomic symptoms. Although cluster headaches are classified as a primary headache disorder, a few cases of inflammatory, vascular or neoplastic conditions have been reported to cause or mimic cluster headaches. This raises the question as to the possible causal relationship between symptoms and an underlying structural lesion that may potentially interfere with the trigemino-autonomic reflex. We hereby report the first pediatric case of a brainstem cavernoma causing cluster headache-like symptoms. Of note, the child experienced pain relief after surgery. With regards to the pathophysiology, the observed ptosis observed in our child during the painful crises might be explained by mass effect of the cavernorma on the cisternal portion of the third cranial nerve. In addition, chronic inflammation of mesencephalic and motor nuclei of the trigeminal nerve by thalamo-pedoncular edema surrounding the lesion may have participated to painful pathways. This case illustrates that cluster headaches may occasionally be secondary to an underlying lesion. This advocates the need for MRI screening, especially as neurosurgical intervention may offer significant symptomatic relief and an improvement in the quality of life of these patients.