Is congenital melanocytic naevus a link between Hirayama disease and moyamoya pattern: a new syndrome or a co-incidence?

A 22-year-old man presented with a history of progressive weakness and wasting of the right hand and forearm for 12 months followed by similar symptoms in the left upper limb for the past 5 months. He also gave a history of episodes of loss of consciousness for the past 5 years with a frequency of one per 3 months. On examination, there were melanocytic naevi-one large lesion in the nape of the neck and multiple satellite lesions. On investigation, the cervical cord MRI was normal. The brain MRI and angiography showed a moyamoya pattern. Thus, this patient had congenital melanocytic naevi with Hirayama disease and moyamoya pattern. He was treated with extracranial-intracranial bypass for moyamoya disease. During 6-month follow-up, he has been stable. Although moyamoya syndrome has been associated with several systemic diseases and conditions, the coexistence of a moyamoya pattern with Hirayama disease and melanocytic naevi has not been described so far.