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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.
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Neurocirurgia , Humanos , Feminino , América Latina , Bibliometria , Procedimentos Neurocirúrgicos , MéxicoRESUMO
Background and Importance Brainstem lesions may be unresectable or unapproachable. Regardless, the histopathological diagnosis is fundamental to determine the most appropriate treatment. We present our experience with transfrontal stereotactic biopsy technique for brainstem lesions as a safe and effective surgical route even when contralateral transhemispheric approach is required for preservation of eloquent tissue. Clinical Presentation Twenty-five patients underwent surgery by transfrontal approach. Medical records were reviewed for establishing the number of patients who had postoperative histopathological diagnosis and postoperative complications. Twenty-four patients (18 adults and 7 children) had histopathological diagnosis. There were 18 astrocytomas documented, of which 12 were high grade and 6 low grade. The other diagnoses included viral encephalitis, post-renal transplant lymphoproliferative disorder, nonspecific chronic inflammation, Langerhans cell histiocytosis, and two metastases. No case was hindered by cerebrospinal fluid loss or ventricular entry. Complications included a case of mesencephalic hemorrhage with upper limb monoparesis and a case of a partially compromised third cranial nerve in another patient without associated bleeding. Conclusion Stereotactic biopsy of brainstem lesions by transfrontal ipsilateral or transfrontal transhemispheric contralateral approaches is a safe and effective surgical approach in achieving a histopathological diagnosis in both pediatric and adult populations.
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OBJECTIVE: Prelemniscal radiation (Raprl) lesions and deep brain stimulation effectively control motor symptoms of Parkinson disease, but individual variations in the stereotactic location of its fiber components constitute a significant concern. The objective of this study was to determine individual variations in the stereotactic location of fiber tracts composing Raprl. METHODS: Raprl fiber composition was determined in a group of 10 Parkinson patients and 10 matched controls using 3T magnetic resonance imaging, brain imaging processed for diffusion-weighted images, tract density imaging, and constrained spherical deconvolution. The stereotactic position of the point of maximal proximity (PMP), which is the point where the most significant number of fibers is concentrated in the smallest volume in the tractography, was evaluated in the right and left hemispheres of the same person, between individuals and between patients and controls for each tract in coordinates "x," "y," and "z." The stereotactic coordinates at which PMP of all tracts meet were statistically determined, representing the recommended aim for this target. RESULTS: Stereotactic coordinates of the 3 fiber tracts composing Raprl, cerebellar-thalamic-cortical, globus pallidus-peduncle-pontine nucleus, and mesencephalic-orbital frontal cortex, did not vary between right and left hemispheres in the same person and between patients and controls. In contrast, PMP variability between individuals was significant, mainly for the mesencephalic-orbitofrontal tract. Therefore, probabilistic tractography can better determine individual variations to plan electrode trajectories. CONCLUSIONS: Individual PMP variations for fiber tracts in Raprl, identified by probabilistic tractography, provide a platform for planning the stereotactic approach to conform volumes for deep brain stimulation and lesions.
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Estimulação Encefálica Profunda , Doença de Parkinson , Substância Branca , Encéfalo , Estimulação Encefálica Profunda/métodos , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/terapia , TálamoRESUMO
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.
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Aggressive behavior in patients with intellectual disability can be resistant to pharmacological treatment and have detrimental consequences to themselves, family members, and caregivers. Hypothalamic deep brain stimulation (DBS) has been used to improve this type of behavior in severe and refractory cases. Here, we present the description and analysis of DBS of the posteromedial hypothalamus (PMH) and its long-term impact as treatment to improve severe and refractory aggressive behaviors, even with previous bilateral hypothalamotomy without improvement in patients with intellectual disability. Eleven patients underwent bilateral DBS of the PMH. Their medical records were reviewed, and the impact on behavior was measured using preoperative and postoperative Modified Overt Aggression Scale (MOAS) during the last follow-up medical visit. Nine of 11 patients presented a significant decrease in the severity of aggressive behavior, with a preoperative and postoperative MOAS average value of 50.5 and 18.7, respectively. An overall improvement of 63% was seen with a mean follow-up time of 4 years. A patient who previously underwent a bilateral hypothalamotomy via radiofrequency was included in this group. During follow-up, 3 patients presented deterioration of symptoms subsequent to pulse generator depletion but made a full clinical recovery after battery replacement. We posit that DBS of the PMH may be a safe and effective in improving severe and refractory aggressive behavior in patients with long-term intellectual disability.
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Estimulação Encefálica Profunda , Deficiência Intelectual , Agressão , Humanos , Deficiência Intelectual/cirurgia , Resultado do TratamentoRESUMO
Individuals with Parkinson's disease (PD) suffer from motor and mental disturbances due to degeneration of dopaminergic and non-dopaminergic neuronal systems. Although they provide temporary symptom relief, current treatments fail to control motor and non-motor alterations or to arrest disease progression. Aiming to explore safety and possible motor and neuropsychological benefits of a novel strategy to improve the PD condition, a case series study was designed for brain grafting of human neural progenitor cells (NPCs) to a group of eight patients with moderate PD. A NPC line, expressing Oct-4 and Sox-2, was manufactured and characterized. Using stereotactic surgery, NPC suspensions were bilaterally injected into patients' dorsal putamina. Cyclosporine A was given for 10 days prior to surgery and continued for 1 month thereafter. Neurological, neuropsychological, and brain imaging evaluations were performed pre-operatively, 1, 2, and 4 years post-surgery. Seven of eight patients have completed 4-year follow-up. The procedure proved to be safe, with no immune responses against the transplant, and no adverse effects. One year after cell grafting, all but one of the seven patients completing the study showed various degrees of motor improvement, and five of them showed better response to medication. PET imaging showed a trend toward enhanced midbrain dopaminergic activity. By their 4-year evaluation, improvements somewhat decreased but remained better than at baseline. Neuropsychological changes were minor, if at all. The intervention appears to be safe. At 4 years post-transplantation we report that undifferentiated NPCs can be delivered safely by stereotaxis to both putamina of patients with PD without causing adverse effects. In 6/7 patients in OFF condition improvement in UPDRS III was observed. PET functional scans suggest enhanced putaminal dopaminergic neurotransmission that could correlate with improved motor function, and better response to L-DOPA. Patients' neuropsychological scores were unaffected by grafting. Trial Registration: Fetal derived stem cells for Parkinson's disease https://doi.org/10.1186/ISRCTN39104513Reg#ISRCTN39104513.
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Mesencéfalo , Células-Tronco Neurais , Doença de Parkinson , Putamen , Adolescente , Adulto , Idoso , Aloenxertos , Dopamina/metabolismo , Feminino , Seguimentos , Humanos , Masculino , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Mesencéfalo/cirurgia , Pessoa de Meia-Idade , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Células-Tronco Neurais/transplante , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Doença de Parkinson/cirurgia , Putamen/metabolismo , Putamen/patologia , Putamen/cirurgiaRESUMO
BACKGROUND: Selective improvement of symptoms may be required when treating Parkinson disease (PD) patients with a predominantly monosymptomatic clinical picture. OBJECTIVE: To define a target in prelemniscal radiation fibers (Raprl) related to the physiopathology of tremor evidenced by tractography. CASE REPORT: We report a patient with predominant unilateral rest and postural tremor, diagnosed as PD based on 80% improvement induced by the administration of L-DOPA/carbidopa, subsequently complicated by motor fluctuations, L-DOPA dyskinesia, and a reduced ON period. A stereotactic radiofrequency lesion was made for tremor control, and postoperative diffusion-weighted imaging (DWI) demonstrated the precise location and extension of the lesioned tract. RESULTS: Perfect control of the tremor was achieved with the patient OFF medication; this has lasted for 5 years, without hypotonia in the treated extremities. DWI revealed a 3.0-mm lesion at the base of the nucleus ventralis intermedius (Vim) interrupting cerebellar-Vim fibers sparing the cerebellar ventralis oralis posterior nucleus component. CONCLUSION: Selective improvement of symptoms is feasible in patients with a predominantly monosymptomatic PD clinical presentation.
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Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/cirurgia , Tremor/diagnóstico por imagem , Tremor/cirurgia , Núcleos Ventrais do Tálamo/diagnóstico por imagem , Núcleos Ventrais do Tálamo/cirurgia , Idoso , Carbidopa/uso terapêutico , Combinação de Medicamentos , Humanos , Levodopa/uso terapêutico , Masculino , Doença de Parkinson/tratamento farmacológico , Resultado do Tratamento , Tremor/tratamento farmacológicoRESUMO
La estimulación cerebral profunda (ECP) es una alternativa de manejo para los pacientescon distonía cervical, un síndrome de etiología múltiple, de presentación variada eincapacitante y refractario al manejo médico, que incluye la toxina botulínica. El artículopresenta el caso de una mujer de 56 años de edad con distonía cervical manifiesta conretrócolis e hiperextensión de columna dorsal, de cuatro años de evolución, consideradarefractaria al tratamiento y con indicación de ECP...
Deep brain stimulation (DBS) is a management alternative for patients with cervicaldystonia, syndrome of multiple etiology, presentation varied, disabling and refractoryto medical management, including botulinum toxin. A case of a 56 year old woman withcervical dystonia manifested by retrocollis and hyperextension dorsal spine of 4 yearsof evolution, considered resistant to treatment that is an indication of DBS is presented...