High-frequency spinal cord stimulation (10 kHz) alters sensory function and nerve fiber density in painful diabetic neuropathy: a pilot prospective open-label study

OBJECTIVE

Spinal cord stimulation at 10 kHz has provided effective pain relief and improved function in painful diabetic peripheral neuropathy. This study aims to confirm the clinical outcomes for 10-kHz spinal cord stimulation treatment of painful diabetic peripheral neuropathy and explore its impact on objective quantitative measures of nerve pathology and function.

METHODS

This single-academic center, prospective, open-label, observational study examined the pain relief success of 10-kHz spinal cord stimulation in patients >18 years of age with diabetic peripheral neuropathy. Patients underwent skin biopsies to measure intra-epidermal nerve fiber densities and corneal confocal microscopy measurements before implantation and at the 3-, 6-, and 12-month follow-up visits. Numerical rating scale for pain, visual analog scale, neuropathy pain scale, Short Form-36, and Neuropen (pin prick and monofilament) assessments were also conducted.

RESULTS

Eight patients met the criteria and were enrolled in the study. A successful trial was achieved in 7 subjects, and 6 completed the study. Significant pain relief (P < .001) was achieved at all follow-up visits. Neurological assessments showed reduced numbers of "absent" responses and increased "normal" responses from baseline to 12 months. Both proximal and distal intra-epidermal nerve fiber densities were higher at 12 months than at baseline (P < .01). Confocal microscopy measurements showed a steady increase in nerve density from baseline (188.8% increase at 12 months; P = .029).

CONCLUSIONS

We observed pain relief and improvements in sensory function after stimulation that were accompanied by increases in lower-limb intra-epidermal nerve fiber density and corneal nerve density. Further evaluation with a blinded and controlled study is needed to confirm the preliminary findings in this study.

The Role of Gender in Neurosurgical Residency Applicants' Letters of Recommendation

BACKGROUND

Letters of recommendation (LORs) are one of the most important components of the neurosurgical residency application. Studies in other fields and surgical subspecialties have found gender bias.

OBJECTIVE

To determine whether neurosurgical LORs contain significant linguistic gendered differences.

METHODS

We performed a retrospective review and linguistic analysis of all LORs submitted on behalf of applicants offered an interview invitation to a single neurosurgical residency program at an academic medical center between 2015-2016 and 2018-2019.

RESULTS

A total of 599 letters from 156 applicants (120 males and 36 females) were included. Background demographics, including United States Medical Licensing Examination (USMLE) Step 1 score and publications, were not significantly different between applicants. Male faculty authored 93% of all letters. Female faculty were more likely to write letters for female applicants than male applicants (12.1% vs 5.5%, P < .001). Letters for women were significantly longer (334 words vs 277 words, P < .001). Overall, 1754 agentic terms and 854 communal terms were coded. Letters for men contained significantly fewer agentic terms (10.7 vs 13.1, per applicant, P < .01) and communal terms (5.2 vs 6.4, P < .034). This difference, however, is nonsignificant when word count was used as a covariate. Female applicants were more significantly likely to be labeled "Outstanding" (2.4 vs 1.6 mentions per applicant).

CONCLUSION

Overall, there are more similarities than differences between genders in LORs for neurosurgical applicants. This finding is at odds with what has previously been reported in most other surgical specialties.

Neuromodulation for Chronic Pelvic Pain: A Single-Institution Experience With a Collaborative Team

BACKGROUND

Secondary to the complex care, involved specialty providers, and various etiologies, chronic pelvic pain patients do not receive holistic care.

OBJECTIVE

To compare our general and neuromodulation cohorts based on referrals, diagnosis, and therapy and describe our neuromodulation patients.

METHODS

A multidisciplinary team was established at our center. The intake coordinator assessed demographics and facilitated care of enrolled patients. Outcomes were compared using minimal clinical important difference of current Numerical Rating Scale (NRS) between patients with neuropathic pain who received neuromodulation and those who did not. The neuromodulation cohort completed outcome metrics at baseline and recent follow-up, including NRS score (best, worst, and current), Oswestry Disability Index (ODI), Beck Depression Inventory, and Pain Catastrophizing Scale.

RESULTS

Over 7 yr, 233 patients were referred to our consortium and 153 were enrolled. A total of 55 patients had neuropathic pain and 44 of those were managed medically. Eleven underwent neuromodulation. A total of 45.5% patients of the neuromodulation cohort were classified as responders by minimal clinically important difference compared to 26.6% responders in the control cohort at most recent follow-up (median 25 and 33 mo, respectively). Outcome measures revealed improvement in NRS at worst (P = .007) and best (P = .025), ODI (P = .014), and Pain Catastrophizing Scale Rumination (P = .043).

CONCLUSION

Eleven percent of patients were offered neuromodulation. There were more responders in the neuromodulation cohort than the conservatively managed neuropathic pain cohort. Neuromodulation patients showed significant improvement at 29 mo in NRS best and worst pain, disability, and rumination. We share our algorithm for patient management.