fMRI after Phalloplasty with Nerve Anastomosis in a Trans-Man Patient

We report on a case of a trans-man patient, who underwent penile reconstruction with the use of a radial forearm flap, urethroplasty, vaginectomy and scrotoplasty, insertion of testicle implants, and penile erection implants, similar to previously described methods. One of the requirements for an ideal phalloplasty is the preservation of erogenous sensitivity, which is often demanded by the patients for fulfilling their sexual well-being. For the first time known to us, we use a functional magnetic resonance imaging following radial forearm flap phalloplasty with nerve anastomosis to assess the cortical activation after clitoral stimulation. The patient was poked with a plastic pen on the neophallus and the groin. Regular block design with T1 and BOLD-T2* images were used. The results contradict the classic Penfield and Rasmussen homunculus, that is, the activations in the primary somatosensory cortex (S1) were bilateral with a left-sided dominance in the lateral parts of the medial postcentral gyrus (same region as the groin), and no activations were observed in the mesial parts of the postcentral gyrus. We also reported bilateral activations with a left-sided dominance in the secondary somatosensory cortex (S2) and near Broca’s area at the sylvian fissure just posterior to ramus ascendens. Our findings are similar to previous studies reporting on imaging related to genital sensitivity.