The 100 Most Cited Articles on Functional Neurosurgery in Latin America: A Scientometric Analysis.

Significant progress has been made in Stereotactic and Functional Neurosurgery (SFN) within Latin America (LATAM), which can be attributed to the rapid advancements in technology and a growing pool of expertise. However, despite the growing importance of this field, a comprehensive scientometric analysis of LATAM contributions is still lacking. The aim of this study is to shed light on the top-cited articles in the field authored by LATAM researchers. A search of the Scopus database was performed using specific keywords in the field of SFN to retrieve the top 100 most cited articles. Only those with LATAM affiliation for the first or corresponding position were included. The 100 top-cited articles were published between 1978 and 2019 across 47 different journals. On average, these articles had a citation count of 97.2 citations. A total of 635 LATAM authors were identified, including 145 women. Notably, the 5 most productive and impactful authors were Velasco F., Velasco M., Velasco A.L., Cukiert A., and Jiménez F. Within the field of SFN, epilepsy accounted for 47% of the documents, while the remaining 53% encompassed research on psychiatric diseases, movement disorders, translational research, pain, and electrical mapping. Epilepsia emerged as the journal with the highest number of articles. Mexico and Brazil contributed the most articles, with the University of São Paulo and the Hospital General de Mexico being the most productive institutions. This scientometric analysis highlights the impactful research contributions from the region, identifies influential authors and institutions, and emphasizes the necessity for additional collaboration and exploration.

Minimally Invasive Retrosigmoidal Parasterional Burr-Hole Approach: Technique and Neuropathic Pain Amelioration after Microvascular Decompression of the Trigeminal Nerve.

BACKGROUND: Trigeminal neuralgia, a common condition in clinical practice, often occurs due to vascular compression caused by aberrant or ectopic arterial or venous vessels. Microvascular decompression through a minimally invasive retrosigmoidal approach has shown high rates of pain control, low complication rates, and excellent therapeutic results. OBJECTIVE: To describe the surgical technique and clinical outcomes in terms of pain relief after microvascular decompression of the trigeminal nerve through a minimally invasive retrosigmoidal parasterional burr-hole technique. METHODS: A group of patients with trigeminal neuralgia refractory to medical management who underwent microvascular decompression were examined. The records of the patients were considered retrospectively (2016-2018), and the outcomes were considered based on the Visual Analogue Scale (VAS) and the Barrow Neurological Institute Pain Scale (BNIPS) added to a technical note of the surgical technique for a minimally invasive retrosigmoidal parasterional burr-hole. RESULTS: Twenty-two patients were evaluated, and clinical assessment after surgical intervention showed a decrease in pain according to the VAS, resulting from an average preoperative state of 9.5 ± 0.37 to a postoperative condition of 1.32 ± 1.28, exhibiting statistically significant changes (p < 0.0001, d = 9.356). On the other hand, in relation to the BNIPS scale, a decrease from an average preoperative status of 4.55 ± 0.25 to a postoperative status at 12 months of 1.73 ± 0.54 was also demonstrated, showing significant changes (p < 0.0001, d = 3.960). CONCLUSION: Microvascular decompression of the trigeminal nerve through a minimally invasive retrosigmoidal parasterional burr-hole is feasible and can be a safe and effective technique for the management of pain. However, further research employing larger sample sizes and longer follow-up periods is necessary.

Neuropathic Pain and Positive Sensory Symptoms in Brachial Plexus Neuropathy: An Exploratory Study of Outcomes after Surgical Decompression and Proposal of a New Sensory Frequency of Symptoms Scale.

BACKGROUND: There are no articles that aim to evaluate the specific role of surgical decompression on the recovery of pain and positive sensory symptoms (PSS) in patients with brachial plexus neuropathy (BPN), as well as the relationship between pain and frequency of sensory manifestations. METHODS: A prospective before and after study was performed, considering the pain intensity through the visual analogue scale (VAS), and the frequency of PSS through a proposed new scale: Sensory Frequency of Symptoms Scale (SFSS). To compare the patients before and after the intervention, a paired T-test, a Wilcoxon signed-rank test, and Cohen's D test were made, coupled with a Spearman analysis in order to establish the relationship between pain and PSS. RESULTS: Sixteen patients were included in the study, the clinical evaluation showed changes in pain according with VAS, going from a mean preoperative state of 8.19 to 1.31 after surgery, showing significant changes (84%, p < 0.00006, Δ = 2.776). Within the PSS, a significant decrease was observed in paresthesias (74%, p < 0.0001, Δ = 1.645), dysesthesias (80%, p < 0.002, Δ = 1.453), and allodynia (70%, p = 0.031, Δ = 0.635). Conversely, the preoperative correlation analysis between pain and dysesthesias/allodynia showed a low and non-significant relationship (R < 0.4, p > 0.05). CONCLUSIONS: Surgical decompression is an effective technique for the relief of pain and sensory manifestations in adult patients with BPN of compressive origin. No relationship was observed between pain and dysesthesias/allodynia. Therefore, during clinical evaluation, they should be considered as independent manifestations, highlighting the need to validate new scales.

Prognostic factors of unilateral prelemniscal radiations radiofrequency lesions: A surgical technique for the treatment of Parkinson's disease motor symptoms.

OBJECTIVE: A group of patients with Parkinson's disease (PD) were managed with unilateral prelemniscal radiation radiofrequency lesions (U-Raprl). The current study aims to evaluate prognostic factors that could influence clinical response. METHODS: Patients previously diagnosed with PD managed with U-Raprl were included in the study, classifying them into two groups according to their percentage of clinical response ( 1.5), Age (p < 0.0001, ∆ = 2.38), Evolution (p < 0.0001, ∆ = 2.38), and post-operative UPDRS (p < 0.01, ∆ = 1.38). The qualitative analysis of the distribution regarding the responder group shows that those patients with an age under 58 years, an evolution fewer than 7 years, and a preoperative HYS score smaller than 2, showed a response ≥ 50% according to the UPDRS-III in all cases. CONCLUSION: U-Raprl is a highly effective procedure with a 5-year persistence of improvement. The most relevant prognostic factors to consider for a clinical response according to UPDRS-III greater than 50% are age under 58 years, less than 7 years of PD evolution, and HYS less or equal to 3.

Neuropathic Pain Relief after Surgical Neurolysis in Patients with Traumatic Brachial Plexus Injuries: A Preliminary Report.

Objective: To evaluate the usefulness of surgical neurolysis for neuropathic pain relief in patients with posttraumatic brachial plexus injury (BPI). Methods: A prospective, longitudinal, nonrandomized, self-controlled before and after study was performed to evaluate the pain changes according to their intensity using the Visual Analogue Scale (VAS), and the sensory recovery after surgery using the British Medical Research Council (BMRC) scale for sensory recovery. To establish significant changes, a paired T-test was performed, and in order to determine the magnitude of these changes, an effect size was measured. α = 0.05. Results: Ten patients were included with an average follow-up of 61.9 ± 53.62 months. The main mechanism of injury was vehicular trauma (70%). A significant decrease in pain after the surgical intervention was observed resulting from an average preoperative state according to VAS of 8.4 ± 1.58, to a postoperative state of 3.4 ± 3.27 (59.52%, p = 0.005, Δ = 1.572), added to a mean sensory improvement (25%) from 2.8 ± 1.62 to 3.5 ± 0.97 after surgery according to BMRC, without statistically significant changes (p=0.062), showing a moderate effect size (Δ = 0.413). Almost all patients showed improvement in the continuous and paroxysmal pattern of pain. No postoperative complications were observed. Discussion. These results suggest that in cases of BPI that originates from a compressive syndrome secondary to the posttraumatic fibrosis that surrounds the nerve structures causing strangulation and inducing hypernociception, the use of surgical neurolysis is an appropriate alternative for patients with medically refractory neuropathic pain.

Bibliometric Analysis of Mexican Publications on Stereotactic and Functional Neurosurgery From 1949 to 2021.

Background: Stereotactic and functional neurosurgery (SFN) is a rapidly evolving field and some emerging countries, especially Mexico, have made significant contributions to this discipline. A bibliometric analysis has never been performed in Latin America, and this would be particularly important to show the areas that remain poorly studied, and design research strategies for the future. Methods: Scopus was queried using keywords pertaining to functional neurosurgery, restricting the affiliation country to Mexico, and considering documents published after 1949. Added to the initial search, a complementary literature exploration by author, considering the publications of the most productive neurosurgeons, was performed. A descriptive statistical analysis was carried out. Results: From 5,109 articles, only 371 were eligible. Scientific production has gradually increased with time. Epilepsy (31%) and movement disorders (27.4%) were the most studied neurological conditions, whereas the other 41.6% corresponded to pain, behavior disorders, spinal cord injuries, neuromodulation, stereotactic biopsies, and SFN history. Level of evidence was predominantly level V (59.1%). Publication output is highly skewed to Mexico City, which represents 78.4% of national production. Relative to factors associated with impact of research, publications in English had more citations (28.5 mean citations per paper), and journals with an impact factor greater than one had more than 10 mean citations per paper. Conclusions: Mexico has experienced an increase in the productivity of SFN literature, addressing the most prevalent issues in the country (epilepsy and motor disorders). However, it is necessary to report studies with a higher level of evidence, as well as to decentralize the research collaborating with national institutions outside Mexico City. On the other hand, it is imperative to promote scientific production in English and in high-impact indexed journals to increase the visibility of our production. We would like to call upon our colleagues in other countries to reproduce our methodology, in order to determine the factors associated with the impact and productivity on SFN research.

A Case of Dentatotomy for Pain and Spasticity and Systematic Review.

BACKGROUND: Surgical interventions for spasticity aim to improve motor function and pain in cases that are refractory to medical treatment. Ablation of the cerebellar dentate nucleus (dentatotomy) may be a useful alternative. CASE REPORT: A 55-year-old male patient with spasticity, secondary to a traumatic cervical spinal cord injury with quadriparesis, had bilateral lumbar DREZotomy with an improvement that lasted for 6 years. Ten years after the DREZotomy, a progressive increased spasticity manifested as spastic diplegia (Ashworth 4) and spontaneous muscle painful spasms (Penn 4), as well as spasticity in the upper extremities, predominantly on the right side (Ashworth 3). A right radio frequency dentatotomy was performed with intraoperative electrophysiological monitoring. Spasticity scales were applied at the following times: preoperative and at 1 and 8 months after surgery. During the first month, the patient presented a clear decrease in spasticity ipsilateral to the side of lesioning (Ashworth 1) and of painful spasms in the lower extremities (Penn 1). After 8 months, spasticity ipsilateral to the injury decreased even more to Ashworth (0), but a progressive increase in muscle spasms of lower extremities was observed (Penn 2). CONCLUSION: Stereotactic dentatotomy may be an effective surgical alternative for management of spasticity associated with painful spasms in selected patients.