Pain-free and pain-controlled survival after sectioning the nervus intermedius in nervus intermedius neuralgia: a single-institution review.

OBJECTIVE: Nervus intermedius neuralgia (NIN) or geniculate neuralgia is a rare facial pain condition consisting of sharp, lancinating pain deep in the ear and can occur alongside trigeminal neuralgia (TN). Studies on the clinical presentation, intraoperative findings, and ultimately postoperative outcomes are extremely limited. The aim of this study was to examine the clinical presentation and surgical findings, and determine pain-free survival after sectioning of the nervus intermedius (NI). METHODS: The authors conducted a retrospective chart review and survey of patients who were diagnosed with NIN at one institution and who underwent neurosurgical interventions. Pain-free survival was determined through chart review and phone interviews using a modified facial pain and quality of life questionnaire and represented as Kaplan-Meier curves. RESULTS: The authors found 15 patients with NIN who underwent microsurgical intervention performed by two surgeons from 2002 to 2016 at a single institution. Fourteen of these patients underwent sectioning of the NI, and 8 of 14 had concomitant TN. Five patients had visible neurovascular compression (NVC) of the NI by the anterior inferior cerebellar artery in most cases where NVC was found. The most common postoperative complaints were dizziness and vertigo, diplopia, ear fullness, tinnitus, and temporary facial nerve palsy. Thirteen of the 14 patients reportedly experienced pain relief immediately after surgery. The mean length of follow-up was 6.41 years (range 8 months to 14.5 years). Overall recurrence of any pain was 42% (6 of 14), and 4 patients (isolated NIN that received NI sectioning alone) reported their pain was the same or worse than before surgery at longest follow-up. The median pain-free survival was 4.82 years ± 14.85 months. The median pain-controlled survival was 6.22 years ± 15.78 months. CONCLUSIONS: In this retrospective review, sectioning of the NI produced no major complications, such as permanent facial weakness or deafness, and was effective for patients when performed in addition to other procedures. After sectioning of the NI, patients experienced 4.8 years pain free and experienced 6.2 years of less pain than before surgery. Alone, sectioning of the NI was not effective. The pathophysiology of NIN is not entirely understood. It appears that neurovascular compression plays only a minor role in the syndrome and there is a high degree of overlap with TN.

More lateral and anterior prefrontal coil location is associated with better repetitive transcranial magnetic stimulation antidepressant response.

BACKGROUND: The left dorsolateral prefrontal cortex (DLPFC) is the most commonly used target for transcranial magnetic stimulation (TMS) in the treatment of depression. The "5-cm rule" is an empiric method used for probabilistic targeting of the DLPFC in most clinical trials. This rule may be suboptimal, as it does not account for differences in skull size or variations in prefrontal anatomy relative to motor cortex location. This study is a post hoc analysis of data from a large repetitive TMS (rTMS) trial in which we examined the variability of coil placement and how it affects antidepressant efficacy. METHODS: Fifty-four depressed subjects enrolled in a randomized, single-site trial received either active rTMS or sham for 3 weeks. Prior to treatment initiation, investigators placed vitamin E capsules at the point of stimulation and used a high-resolution magnetic resonance imaging (MRI) scan to image these fiducials relative to anatomy. We employed a semiautomated imaging-processing algorithm to localize the cortical region stimulated. RESULTS: Active TMS significantly reduced Hamilton Depression Rating Scale (HDRS) scores. A linear model for this improvement involving the coordinates of the stimulated cortex location, age, and treatment condition was highly significant. Specifically, individuals with more anterior and lateral stimulation sites were more likely to respond. CONCLUSIONS: These results suggest that within the general anatomical area targeted by the 5-cm rule, placing the TMS coil more laterally and anteriorly is associated with improved response rates in TMS depression studies. Controlled studies testing this anatomical hypothesis are needed.