Sphenoid sinus mucocele causing ptosis with pupil-spared ophthalmoplegia: A hint on carotid artery Doppler ultrasound.

Objective: Sphenoid sinuses mucocele (SSM) is an uncommon cause of orbital apex syndrome (OAS). Diagnosis of neurological complications in SSM might be delayed when the expansion of mucocele beyond the sinuses is not evident in conventional sinuses imaging.Methods: We present a case of a 76-years old man with spared-pupil ophthalmoplegia associated with ptosis caused by a unilateral left SSM in which internal carotid artery Doppler ultrasound showed distal sub-occlusion waves pattern.Results: Sinus occupation was noted in the magnetic resonance imaging (MRI) and was further evaluated in computed tomography (CT) scan and MR angiography. Nor CT or MR angiography showed clear evidence of neighboring structures compression. Doppler ultrasound of internal carotid showed high-resistance waveforms and decreased wave velocities helping diagnosis. Structures compression was confirmed intra-operatively and the patient was discharged asymptomatic after sphenoid sinus drainage.Conclusion: In this first report of carotid Doppler ultrasound findings in a patient with a neurological presentation of a sphenoid sinus mucocele, a high-resistance waveform of the internal carotid may help differentiate uncomplicated sinusitis from invasive mucocele.