Isolated Uhthoff phenomenon as first manifestation of multiple sclerosis: a case report

BACKGROUND: The Uhthoff phenomenon (UP) is a temporary worsening of neurological symptoms due to an increase in body temperature, commonly observed in demyelinating diseases, especially multiple sclerosis (MS). CASE PRESENTATION: A 37-year-old female presented with a four-year history of transient vision impairment in the right eye, particularly during dancing. Visual evoked potentials (VEP) revealed prolonged P100 latency and reduced amplitude of the right eye. Optical coherence tomography (OCT) confirmed thinning of the macular ganglion cell and inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) in the right eye with significant inter-eye differences, consistent with a unilateral optic nerve lesion. Magnetic resonance imaging (MRI) findings of periventricular, pons and spinal cord lesions, along with positive oligoclonal bands in cerebrospinal fluid, confirmed MS diagnosis. CONCLUSIONS: This case underscores the importance of recognizing UP as a potential early indicator of MS. Specific diagnostic tools, such as OCT, VEP, and MRI, can be used to objectify optic nerve involvement and should be considered to identify underlying demyelinating conditions. Early diagnosis of MS can facilitate a timely initiation of therapies and improve patient outcomes. It is essential for clinicians to consider UP for better clinical management of MS.