Involvement of Satellite Cell Activation via Nitric Oxide Signaling in Ectopic Orofacial Hypersensitivity.

: The mechanical head-withdrawal threshold (MHWT) was significantly reduced following inferior alveolar nerve transection (IANX) in rats. Nitrate and nitrite synthesis was dramatically increased in the trigeminal ganglion (TG) at 6 h after the IANX. The relative number of neuronal nitric oxide synthase (nNOS)-immunoreactive (IR) cells was significantly higher in IANX rats compared to sham-operated and N-propyl-L-arginine (NPLA)-treated IANX rats. On day 3 after NPLA administration, the MHWT recovered considerably in IANX rats. Following L-arginine injection into the TG, the MHWT was significantly reduced within 15 min, and the mean number of TG cells encircled by glial fibrillary acidic protein (GFAP)-IR cells was substantially higher. The relative number of nNOS-IR cells encircled by GFAP-IR cells was significantly increased in IANX rats. In contrast, after NPLA injection into the TG, the relative number of GFAP-IR cells was considerably reduced in IANX rats. Fluorocitrate administration into the TG significantly reduced the number of GFAP-IR cells and prevented the MHWT reduction in IANX rats. The present findings suggest that following IANX, satellite glial cells are activated via nitric oxide (NO) signaling from TG neurons. The spreading satellite glial cell activation within the TG results in mechanical hypersensitivity of face regions not directly associated with the trigeminal nerve injury.

Intranasal self-administration of local anesthetic (ropivacaine) for sphenopalatine ganglion block, for treatment of second trigeminal branch neuralgia secondary to maxillary sinus curettage: A case report. / Autoadministración intranasal de anestésico local (ropivacaína) para bloqueo del ganglio esfenopalatino, para tratamiento de neuralgia de la segunda rama del trigémino secundaria a curetaje del seno maxilar: informe de un caso.

Trigeminal neuralgia (TN) is a severe and often underestimated facial pain that affects quality of life. Pharmacological treatment is insufficient for pain control in 30% of cases and, although intervention techniques may be effective, there is a possibility of relapse and associated complications. The second division of the trigeminal nerve (V2) runs through the sphenopalatine ganglion (SPG), which is anatomically accessible to blocking due to its superficial location in the nasal cavity. We report a clinical case of a patient with uncontrolled V2 TN that was put on ambulatory self-administered SPG block with nasal swabs soaked in 0.75% ropivacaine. In the follow-up visits, we confirmed that this adjuvant treatment provided a significant pain relief over 24hours with a decrease in the number of exacerbations.