1.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
2.Regulatory roles of eugenol in paraquataltered SNCA/LZTS3/MAPT in the cerebellum of Wistar rats
Obinna Onwe UCHEWA ; Augustine Oseloka IBEGBU ; Samuel Okoronkwo OKAFOR ; Joseph Alo NWAFOR ; Ogugua Augustine EGWU
Laboratory Animal Research 2025;41(1):57-70
Background:
The Microtubules-associated protein tau (MAPT), alpha-synuclein (SNCA), and leucine zipper tumor suppressor 3 (LZTS3) genes are implicated in neurodegeneration and tumor suppression, respectively. This study investigated the regulatory roles of eugenol on paraquat-altered genes.
Results:
Forty male Wistar rats divided into five groups of eight rats were used. The control group received normal saline; the Paraquat (PQ)-untreated group received only Paraquat. The low dose of eugenol was 200 mg/kg, the medium dose of eugenol was 400 mg/kg, and the high dose of eugenol was 600 mg/kg. All groups except the control group received 10 mg/kg of PQ orally for 14 days at one-day intervals, allowing PQ in the rats for 28 days.Eugenol treatment started on the 29th and lasted 14 days. Motor impairments were determined using wire string and beam-walk; biomarkers were estimated using cerebellar homogenates, while frozen cerebellum was used to study LZTS3, MAPT, and SNCA gene expression. LZTS3 was significantly suppressed in the PQ-untreated group and highly expressed in the eugenol-treated group. The MAPT and SNCA genes were overexpressed in the PQ-untreated group compared to the control group. Eugenol significantly decreased the expression of these genes compared to that in the PQ-untreated group. Antioxidants were reduced considerably, and oxidative stress markers were increased significantly, which could have caused increased protein fibrillation and reduced limb functionality. Histology revealed that eugenol mitigated the alterations caused by Paraquat.
Conclusions
PQ can enhance tumor expression in addition to causing neurotoxicity, which decreases limb functionality, while eugenol, an antioxidant, can mitigate the effects of PQ.
3.The Utilization of Navigation and Emerging Technologies With Endoscopic Spine Surgery: A Narrative Review
Abhinav K. SHARMA ; Rafael Garcia DE OLIVEIRA ; Siravich SUVITHAYASIRI ; Piya CHAVALPARIT ; Chien Chun CHANG ; Yong H. KIM ; Charla R. FISCHER ; Sang LEE ; Samuel CHO ; Jin-Sung KIM ; Don Young PARK
Neurospine 2025;22(1):105-117
Endoscopic spine surgery (ESS) is growing in popularity worldwide. An expanding body of literature demonstrates rapid functional recovery with reduced morbidity compared to open techniques. Both full endoscopic spine surgery, or uniportal endoscopy, and unilateral biportal endoscopy (UBE) can be employed in conjunction with various navigation and enabling technologies for assistance with localization of anatomic orientation and assessment of the intraoperative target spinal pathology. This review article describes various navigation technologies in ESS, including 2-dimensional (2D) fluoroscopic imaging, 2D fluoroscopic navigation, 3-dimensional C-arm navigation, augmented reality, and spinal robotics. Employment of enabling navigation and emerging technology with the registration of patient-specific anatomy enables clear delineation of anatomic landmarks and facilitation of a successful procedure. Additionally, avoidance of common pitfalls during use of navigation systems in ESS is discussed in this review.
4.Open Versus Minimally Invasive Spine Surgery in the Treatment of Single-Level Degenerative Lumbar Spondylolisthesis: An AO Spine Global Cross-Sectional Study
Luca AMBROSIO ; Sathish MUTHU ; Samuel K. CHO ; Micheal S. VIRK ; Juan P. CABRERA ; Patrick C. HSIEH ; Andreas K. DEMETRIADES ; Stipe ĆORLUKA ; S. Tim YOON ; Gianluca VADALÀ ;
Neurospine 2025;22(1):40-47
Objective:
This study aims to assess global trends in the use of open surgery versus minimally invasive surgery (MIS) for the treatment of single-level L4–5 degenerative lumbar spondylolisthesis (DLS).
Methods:
A cross-sectional online survey issued by the AO Spine Knowledge Forum Degenerative was conducted among AO Spine members between July and September 2023. Participants were presented with 3 clinical cases of L4–5 grade 1 DLS, each with varying degrees of stenosis and instability. The survey captured surgeon demographics and preferences for open versus MIS approaches. Statistical analysis, including chi-square tests and logistic regression, was performed to explore associations between surgical choices and surgeon demographics.
Results:
A total of 943 surgeons responded, with 479 completing the survey. Open surgery was the preferred approach in all 3 cases (58.8%, 57.3%, and 42.4%, respectively), particularly in cases involving central and bilateral foraminal stenosis. MIS was the second most common choice, particularly for unilateral foraminal stenosis with mild instability (38.8%). Surgeons’ preferences varied significantly by region, age, and fellowship training, with younger and fellowship-trained surgeons more likely to prefer MIS.
Conclusion
The study highlights the continued predominance of open surgery for DLS, especially in complex cases, despite the growing acceptance of MIS. Significant regional and demographic variations in surgical preferences suggest the need for tailored guidelines and standardized training protocols to optimize patient outcomes. Future research should focus on the long-term efficacy of these approaches and the impact of evolving technologies on surgical decision-making.
5.Radial Type Low-Intensity Extracorporeal Shockwave Therapy Enhances Penile Microvascular Perfusion in an Aging Rat Model: A Novel Interventional Strategy to Treat Erectile Dysfunction
Saager Tilak CHAWLA ; Jad SHAHAN ; Nolan SOUTIPAN ; Samuel Ryan SORKHI ; Yong Sun CHOI ; Woong Jin BAE ; Sae Woong KIM ; Tung-Chin HSIEH ; Mahadevan Raj RAJASEKARAN
The World Journal of Men's Health 2025;43(2):396-406
Purpose:
Physiological aging is associated with microvascular dysfunction, including in the penis, and this may contribute to age-related erectile dysfunction (ED). Low-intensity extracorporeal shockwave therapy (Li-ESWT) is a non-invasive intervention for ED, but its effect on penile microvascular function, remains unclear. Our objectives are to (i) evaluate the effect of Li-ESWT (specifically radial type ESWT [rESWT]) on penile microvascular perfusion (PMP) in aging rats, (ii) elucidate a possible mechanism, and (iii) evaluate its impact on angiogenic and smooth muscle biomarkers in cavernosal tissue.
Materials and Methods:
Male rats (n=9; 15–18 months) were anesthetized and subjected to rESWT while monitoring PMP. The nitric oxide (NO) pathway involvement was assessed by measuring the effect of rESWT on PMP following an intracavernosal injection of N(G)-nitroarginine methyl ester (L-NAME) (NO synthase inhibitor). To elucidate the cellular mechanism, another group of rats received repeated rESWT (n=4) or no treatment (n=4) three times/week for two weeks. Rats were euthanized at the end of the study and penile tissues were analyzed for angiogenic markers (vascular endothelial growth factor-A [VEGF-A], endothelial nitric oxide synthase [eNOS]) and smooth muscle content (α-actin) using immunostaining, Western blot, and quantitative polymerase chain reaction (qPCR).
Results:
rESWT resulted in more than a 2-fold increase in PMP (from 68.5 arbitrary units; 163.7 AU). L-NAME injection produced a <40%–50% decrease (185.3 to 101.0 AU) in rESWT-induced PMP response. Immunostaining revealed increased α-actin, eNOS, and VEGF-A in the cavernosum and these findings were confirmed by qPCR and Western blot results.
Conclusions
rESWT improved PMP, which may be mediated via increased VEGF expression, which stimulates the NO/cyclic guanosine monophosphate pathway, resulting in sustained PMP. rESWT devices could offer a safe, non-invasive treatment for age-related ED.
6.A viable alternative to local flaps in the hand? A case report demonstrating the successful use of NovoSorb Biodegradable Temporising Matrix in hand trauma
Iain ROY ; Robert MANTON ; Samuel COULSON-WOODLEY ; Patrick GOON
Archives of hand and microsurgery 2025;30(2):110-113
Soft tissue reconstruction is a common requirement in managing hand trauma, and an eclectic mixture of flaps has been described for when vascularized tissue is required. The authors report the novel use of NovoSorb Biodegradable Temporising Matrix (NovoSorb BTM; PolyNovo Biomaterials) for a finger defect that would have ordinarily necessitated coverage by vascularized tissue. The patient made a positive and timely recovery, with return to his premorbid level of functioning. The authors have continued to utilize NovoSorb BTM in a number of cases and found it to represent a robust and versatile addition to our reconstructive quiver for managing soft tissue defects in the hand.
7.Ruptured aneurysm of the medial posterior choroidal artery in the pineal region: A rare location easily missed
Samuel HALL ; Difei WANG ; Vishnu SURESH ; Nicholas BORG ; Diederik BULTERS
Journal of Cerebrovascular and Endovascular Neurosurgery 2025;27(1):66-70
Aneurysms of the pineal region are rare and theoretically could arise from the medial posterior choroidal artery (MPChoA) or lateral posterior choroidal arteries (LPChoA). A 64-year-old lady with subarachnoid haemorrhage (SAH) and intraventricular haemorrhage (IVH) due to a ruptured MPChoA aneurysm was treated with microsurgical aneurysm excision via an occipital interhemispheric approach. This case demonstrates the importance of being mindful of rare aneurysm locations when initial vascular imaging in SAH appears normal.
8.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
9.Regulatory roles of eugenol in paraquataltered SNCA/LZTS3/MAPT in the cerebellum of Wistar rats
Obinna Onwe UCHEWA ; Augustine Oseloka IBEGBU ; Samuel Okoronkwo OKAFOR ; Joseph Alo NWAFOR ; Ogugua Augustine EGWU
Laboratory Animal Research 2025;41(1):57-70
Background:
The Microtubules-associated protein tau (MAPT), alpha-synuclein (SNCA), and leucine zipper tumor suppressor 3 (LZTS3) genes are implicated in neurodegeneration and tumor suppression, respectively. This study investigated the regulatory roles of eugenol on paraquat-altered genes.
Results:
Forty male Wistar rats divided into five groups of eight rats were used. The control group received normal saline; the Paraquat (PQ)-untreated group received only Paraquat. The low dose of eugenol was 200 mg/kg, the medium dose of eugenol was 400 mg/kg, and the high dose of eugenol was 600 mg/kg. All groups except the control group received 10 mg/kg of PQ orally for 14 days at one-day intervals, allowing PQ in the rats for 28 days.Eugenol treatment started on the 29th and lasted 14 days. Motor impairments were determined using wire string and beam-walk; biomarkers were estimated using cerebellar homogenates, while frozen cerebellum was used to study LZTS3, MAPT, and SNCA gene expression. LZTS3 was significantly suppressed in the PQ-untreated group and highly expressed in the eugenol-treated group. The MAPT and SNCA genes were overexpressed in the PQ-untreated group compared to the control group. Eugenol significantly decreased the expression of these genes compared to that in the PQ-untreated group. Antioxidants were reduced considerably, and oxidative stress markers were increased significantly, which could have caused increased protein fibrillation and reduced limb functionality. Histology revealed that eugenol mitigated the alterations caused by Paraquat.
Conclusions
PQ can enhance tumor expression in addition to causing neurotoxicity, which decreases limb functionality, while eugenol, an antioxidant, can mitigate the effects of PQ.
10.The Utilization of Navigation and Emerging Technologies With Endoscopic Spine Surgery: A Narrative Review
Abhinav K. SHARMA ; Rafael Garcia DE OLIVEIRA ; Siravich SUVITHAYASIRI ; Piya CHAVALPARIT ; Chien Chun CHANG ; Yong H. KIM ; Charla R. FISCHER ; Sang LEE ; Samuel CHO ; Jin-Sung KIM ; Don Young PARK
Neurospine 2025;22(1):105-117
Endoscopic spine surgery (ESS) is growing in popularity worldwide. An expanding body of literature demonstrates rapid functional recovery with reduced morbidity compared to open techniques. Both full endoscopic spine surgery, or uniportal endoscopy, and unilateral biportal endoscopy (UBE) can be employed in conjunction with various navigation and enabling technologies for assistance with localization of anatomic orientation and assessment of the intraoperative target spinal pathology. This review article describes various navigation technologies in ESS, including 2-dimensional (2D) fluoroscopic imaging, 2D fluoroscopic navigation, 3-dimensional C-arm navigation, augmented reality, and spinal robotics. Employment of enabling navigation and emerging technology with the registration of patient-specific anatomy enables clear delineation of anatomic landmarks and facilitation of a successful procedure. Additionally, avoidance of common pitfalls during use of navigation systems in ESS is discussed in this review.

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