Facial nerve involvement in recurrent painful ophthalmoplegic neuropathy (RPON) represents one of the least documented – and arguably atypical – aspects of this already poorly characterized condition, particularly when associated with the simultaneous involvement of multiple cranial nerves.

Kim et al. ^{Reference Kim, Kang, Lee and Lee1} make a highly valuable contribution to broadening the understanding of such neuropathic clinical manifestations, with specific regard to the potential – albeit exceptional – involvement of the seventh cranial nerve in the context of RPON. Of considerable interest are the diagnostic investigations performed, described in detail for each individual patient. Beyond the diagnosis itself and the distinctive nature of the cases reported, the article stands out for the systematic diagnostic pathway proposed within the differential diagnosis. A clinical reasoning process that should consistently be followed in cases of cranial nerve palsy is carefully documented by the authors, who guide the reader toward the proposed diagnostic conclusion only after other causes of cranial nerve palsy have been systematically excluded.

The differential diagnosis with Tolosa–Hunt syndrome (THS) deserves particular attention. While RPON characteristically demonstrates cranial nerve enhancement within the cisternal (subarachnoid) segment on contrast-enhanced MRI, THS typically involves the cavernous sinus, superior orbital fissure or orbit. ^{Reference Kim, Lee, Lee, Choi and Kim2,Reference Frattini, Iodice and Spagnoli3} Furthermore, whereas involvement of the optic nerve or branches of the trigeminal nerve may occur in THS in addition to the ocular motor nerves, simultaneous involvement of these structures is very rarely reported in the context of RPON. ^{Reference Furia, Liguori and Donadio4,5}

Equally noteworthy is the presentation of patient photographs, which may more effectively guide the clinician in diagnosis and iconographic comparison. The chronological sequence of events, supported by timelines that facilitate an understanding of disease progression, further highlights how manifestations of facial nerve involvement in RPON may follow a recurrent course, at times requiring treatment with intravenous corticosteroids. The correlation between facial neuropathy and RPON remains to be definitively established, and further studies will be necessary to this end; nevertheless, this article provides an excellent foundation from which to proceed.