Cluster Headache as the Index Event in MS: A Case Report

We report a 42‐year‐old woman who presented with cluster headache (CH) in association with other neurological symptoms as the index event of new onset multiple sclerosis (MS). Her initial symptoms were left‐sided headache with ipsilateral lacrimation and nasal congestion associated with ipsilateral facial numbness. A subsequent similar headache attack was also associated with ipsilateral arm ataxia and gait ataxia. She had many additional short headache attacks without focal neurological symptoms. Her cluster‐like headache attacks have not recurred since intiation of dimethyl fumarate. Our patient illustrates that cluster‐like headache attacks can occur as a first symptom of MS, in our patient in association with other neurological symptoms. A striking finding in our patient was a large demyelinating lesion in the brachium pontis ipsilateral to the headaches, although additional supratentorial demyelinating lesions were also present. Although CH associated with MS is rare, our patient and the two other reported patients with MS and CH with similar ipsilateral brachium pontis lesions suggest that the lesions in this location may have played a role in the generation of the cluster‐like attacks.