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1.
BMJ Open Ophthalmol ; 9(1)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38565231

RESUMEN

BACKGROUND: Pterygium is a common ocular surface disorder that requires surgical intervention for treatment. Conjunctival autografts are preferred over simple excision due to lower recurrence rates. This systematic review and meta-analysis compared the modified sutureless glue-free (MSGF) method with conventional sutures (CS) for conjunctival autograft fixation in primary pterygium surgery. METHODS: A comprehensive search was conducted in MEDLINE, Embase, CENTRAL, Google Scholar and ClinicalTrials.gov for randomised controlled trials (RCTs) comparing MSGF and CS conjunctival autografts. Outcome measures included operation time, recurrence and postoperative complications. Standardised mean difference (SMD) and risk ratio (RR) were used for continuous and dichotomous outcomes, respectively. RESULTS: 11 RCTs involving 833 participants were included. The analysis revealed that MSGF had a significantly shorter operation time compared with CS (SMD -3.704, 95% CI -5.122 to -2.287, p<0.001). CS was associated with a higher risk of foreign body sensation (RR 0.22, 95% CI 0.06 to 0.74, p=0.01). MSGF was associated with a higher risk of graft dehiscence (RR 9.01, 95% CI 2.74 to 29.68, p=0.000) and graft retraction (RR 2.37, 95% CI 1.17 to 4.77, p=0.02). No significant differences were found in recurrence, graft haemorrhage, granuloma, Dellen and conjunctival oedema. CONCLUSION: Using the MSGF technique in conjunctival autograft fixation for pterygium surgery reduces operation time by relying solely on the patient's blood for fixation. However, it increases the risk of graft dehiscence and retraction. However, CS is linked to a higher likelihood of experiencing foreign body sensations. Understanding the learning curve and surgeon familiarity with novel techniques is crucial for optimising patient care and surgical outcomes, while individualised decision-making is necessary considering the advantages and disadvantages of each approach. Further research is warranted to minimise complications and optimise surgical outcomes.


Asunto(s)
Conjuntiva/anomalías , Cuerpos Extraños , Pterigion , Humanos , Pterigion/cirugía , Autoinjertos , Adhesivo de Tejido de Fibrina , Recurrencia , Conjuntiva/cirugía , Suturas
5.
Am J Case Rep ; 25: e943514, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38622861

RESUMEN

BACKGROUND Unintentional medication-blister ingestion is rare but frequently leads to intestinal perforation. The diagnosis of intestinal perforation following blister ingestion is often delayed because of an unreliable history and nonspecific clinical presentation. The purpose of this case report is to raise awareness about a rare but difficult diagnosis and its importance in avoiding potentially fatal events. CASE REPORT Herein, we describe successful cases of surgical and endoscopic removal after blister ingestion. The first case was that of a polymorbid 75-year-old man who presented with acute onset of abdominal pain in the right upper quadrant and epigastric regions. No indication of the cause was observed on initial computed tomography (CT). The patient developed an acute abdomen, and emergency laparotomy was performed, during which 2 small perforations were observed in the terminal ileum, and an empty tablet blister was retrieved. The second patient was a 55-year-old man who presented with a considerable lack of awareness. On the initial CT, a subdural hematoma, aspiration, and an unidentified foreign body in the stomach were observed. Gastroscopy was performed after emergency craniotomy. In addition to the initial foreign body, a second object, which had gone unnoticed on the initial CT, was found and removed from the esophagus. CONCLUSIONS With an increased risk of perforation and difficult clinical and radiological diagnoses, prophylactic measures and special awareness of high-risk patients are particularly important.


Asunto(s)
Cuerpos Extraños , Perforación Intestinal , Masculino , Humanos , Anciano , Persona de Mediana Edad , Perforación Intestinal/etiología , Perforación Intestinal/cirugía , Perforación Intestinal/diagnóstico , Vesícula , Íleon , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía , Ingestión de Alimentos
6.
BMC Pediatr ; 24(1): 246, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582899

RESUMEN

BACKGROUND: Button battery (BB) ingestions (BBI) are increasingly prevalent in children and constitute a significant, potentially life-threatening health hazard, and thus a pediatric emergency. Ingested BBs are usually charged and can cause severe symptom within 2 h. Discharged BBs ingestion is very rare and protracted symptom trajectories complicate diagnosis. Timely imaging is all the more important. Discharged BBs pose specific hazards, such as impaction, and necessitate additional interventions. CASE PRESENTATION: We present the case of a previously healthy 19-month-old girl who was admitted to our pediatric university clinic in Germany for assessment of a three-month history of intermittent, mainly inspiratory stridor, snoring and feeding problems (swallowing, crying at the sight of food). The child's physical examination and vital signs were normal. Common infectious causes, such as bronchitis, were ruled out by normal lab results including normal infection parameters, negative serology for common respiratory viruses, and normal blood gas analysis, the absence of fever or pathological auscultation findings. The patient's history contained no evidence of an ingestion or aspiration event, no other red flags (e.g., traveling, contact to TBC). Considering this and with bronchoscopy being the gold standard for foreign body (FB) detection, an x-ray was initially deferred. A diagnostic bronchoscopy, performed to check for airway pathologies, revealed normal mucosal and anatomic findings, but a non-pulsatile bulge in the trachea. Subsequent esophagoscopy showed an undefined FB, lodged in the upper third of the otherwise intact esophagus. The FB was identified as a BB by a chest X-ray. Retrieval of the battery proved extremely difficult due to its wedged position and prolonged ingestion and required a two-stage procedure with consultation of Ear Nose Throat colleagues. Recurring stenosis and regurgitation required one-time esophageal bougienage during follow-up examinations. Since then, the child has been asymptomatic in the biannual endoscopic controls and is thriving satisfactorily. CONCLUSION: This case describes the rare and unusual case of a long-term ingested, discharged BB. It underscores the need for heightened vigilance among healthcare providers regarding the potential hazards posed by discharged BBIs in otherwise healthy children with newly, unexplained stridor and feeding problems. This case emphasizes the critical role of early diagnostic imaging and interdisciplinary interventions in ensuring timely management and preventing long-term complications associated even to discharged BBs.


Asunto(s)
Cuerpos Extraños , Femenino , Humanos , Lactante , Ingestión de Alimentos , Esofagoscopía , Esófago , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico por imagen , Ruidos Respiratorios/etiología
7.
Artículo en Inglés | MEDLINE | ID: mdl-38631862

RESUMEN

Intrathoracic needles are rarely used in clinical practice. They can migrate within the body, injure large blood vessels and other organs, and cause severe complications. We report an interesting case of intrathoracic needle removal using video-assisted thoracoscopic surgery. The needle was inserted under the left clavicle, penetrated the mediastinum, and migrated into the right thoracic cavity. Although pneumothorax developed during the disease course, no severe complications were observed. This rare case illustrates the course of needle migration from the mediastinum into the thoracic cavity. Prompt imaging and surgical removal of foreign bodies are necessary in cases of intrathoracic foreign bodies.


Asunto(s)
Cuerpos Extraños , Migración de Cuerpo Extraño , Cavidad Torácica , Humanos , Mediastino , Resultado del Tratamiento , Cavidad Torácica/cirugía , Cuerpos Extraños/cirugía , Cirugía Torácica Asistida por Video/métodos , Migración de Cuerpo Extraño/cirugía
9.
Spinal Cord Ser Cases ; 10(1): 28, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38653970

RESUMEN

INTRODUCTION: Retained shrapnel from gunshots is a common occurrence; however, retained shrapnel within the spinal canal is exceedingly uncommon. Guidelines for removal and treatment of these cases are a difficult topic, as surgical removal is not necessarily without consequence, and retention can lead to possible further injury or a secondary disease process of plumbism, which can be difficult to diagnose in this population. CASE PRESENTATION: This case report provides a unique example of a young patient with retained shrapnel from a gunshot. This patient suffered an initial spinal cord injury due to a gunshot and secondarily presented with abdominal pain, fatigue, elevated blood lead levels, and was diagnosed with plumbism. This was addressed with operative removal of shrapnel and posterior instrumented spinal fusion, resulting in decreased lead levels and symptom resolution postoperatively. DISCUSSION: Lead toxicity risk in patients with retained shrapnel, particularly in the spine, warrants vigilant monitoring. While management guidelines lack consensus, symptomatic lead toxicity may necessitate intervention. Residual neurological deficits complicate evaluation, emphasizing individualized management decisions.


Asunto(s)
Cuerpos Extraños , Intoxicación por Plomo , Traumatismos de la Médula Espinal , Heridas por Arma de Fuego , Humanos , Traumatismos de la Médula Espinal/diagnóstico , Cuerpos Extraños/complicaciones , Cuerpos Extraños/cirugía , Heridas por Arma de Fuego/complicaciones , Heridas por Arma de Fuego/cirugía , Masculino , Intoxicación por Plomo/diagnóstico , Intoxicación por Plomo/etiología , Plomo/sangre , Fusión Vertebral/métodos , Adulto
11.
J Int Med Res ; 52(3): 3000605241237890, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38497130

RESUMEN

Multi-slice computed tomography (MSCT) is the primary method for the detection and visualization of foreign bodies in the pulmonary artery because it provides high sensitivity and accuracy. It is very difficult to diagnose a patient with a non-iatrogenic pulmonary artery foreign body who does not have a history of a penetrating trauma. This case report describes a 36-year-old male that presented with coughing and haemoptysis. Based on conventional coronal and cross-sectional CT, the foreign body was misdiagnosed as pulmonary tuberculosis and pulmonary artery thrombosis. During treatment of the bronchial artery embolization and anti-tuberculosis therapy, the patient continued to experience haemoptysis. After further analysis of the pulmonary artery CT angiography images and curved multiplane reconstruction, an approximately 6-cm long toothpick was identified in the pulmonary artery with an unclear entry route. After surgery to remove the toothpick, symptoms of coughing and haemoptysis were resolved. This current case demonstrated that multiplane reconstruction in MSCT can improve the detection and visualization of pulmonary artery foreign bodies, which can aid in the diagnosis of pulmonary artery diseases of unknown cause.


Asunto(s)
Cuerpos Extraños , Arteria Pulmonar , Adulto , Humanos , Masculino , Angiografía , Tos , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía , Cuerpos Extraños/complicaciones , Hemoptisis/diagnóstico por imagen , Hemoptisis/etiología , Arteria Pulmonar/diagnóstico por imagen , Arteria Pulmonar/cirugía , Tomografía Computarizada por Rayos X/métodos
12.
Arq Bras Oftalmol ; 87(3): e20230033, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38537046

RESUMEN

PURPOSE: This study aims to compare the initial ocular discomfort symptoms resulting from trabeculectomy and Ahmed glaucoma valve implantation surgeries. METHODS: A prospective comparative study was conducted. The evaluation of ocular discomfort employed a questionnaire designed to identify the frequency and severity of distinct symptoms: ocular pain, general discomfort, tearing, foreign body sensation, and burning. This questionnaire was administered prior to surgery as a baseline, and subsequently at 7, 30, and 90 days post-surgery. Simultaneously, the Ocular Surface Disease Index (OSDI) was applied at these same time intervals. RESULTS: The study encompassed a total of 17 patients (9 undergoing trabeculectomy and 8 undergoing Ahmed glaucoma valve implantation). The Ahmed glaucoma valve implantation group exhibited higher tearing levels at baseline (p=0.038). However, no statistically significant differences in symptoms were observed between the two surgeries at 7 and 30 days post-surgery. At the 90-day mark following surgery, patients who had undergone trabeculectomy reported a significantly higher foreign body sensation (p=0.004). Although OSDI scores did not differ between groups at baseline, the trabeculectomy group showed significantly higher OSDI scores than the Ahmed glaucoma valve implantation group at 7, 30, and 90 days after surgery (p<0.05). CONCLUSION: Post-surgery, patients who had undergone trabeculectomy experienced increased foreign body sensation. Trabeculectomy appears to cause greater early postoperative ocular discomfort compared to the Ahmed glaucoma valve implantation group.


Asunto(s)
Cuerpos Extraños , Implantes de Drenaje de Glaucoma , Glaucoma , Trabeculectomía , Humanos , Trabeculectomía/efectos adversos , Estudios Prospectivos , Presión Intraocular , Implantes de Drenaje de Glaucoma/efectos adversos , Glaucoma/etiología , Implantación de Prótesis/efectos adversos , Cuerpos Extraños/complicaciones , Cuerpos Extraños/cirugía , Resultado del Tratamiento , Estudios Retrospectivos
13.
Clin Toxicol (Phila) ; 62(2): 129-130, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38477964

RESUMEN

INTRODUCTION: Some tobacco sticks, such as TEREA™ heat sticks for IQOS ILUMA™, contain a blade. Both the nicotine part of the device and the micro-blade can be ingested by children. CASE SUMMARIES: We report two children, an 18-month-old boy and a 10-month-old girl, who ingested a heat stick containing a micro-blade. IMAGES: Radiography revealed the micro-blade to be in the child's mouth in the first case and the stomach in the second. Endoscopy was performed on the second child, confirming the presence of the blade in the stomach. CONCLUSION: We recommend performing a radiograph on all children who ingest tobacco sticks containing a micro-blade. If a metallic object is present, we recommend endoscopic removal to avoid traumatic lesions from the sharp edges.


Asunto(s)
Cuerpos Extraños , Calor , Productos de Tabaco , Femenino , Humanos , Lactante , Masculino , Ingestión de Alimentos , Cuerpos Extraños/diagnóstico por imagen , Radiografía , Productos de Tabaco/efectos adversos
14.
Open Vet J ; 14(2): 652-663, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38549572

RESUMEN

Background: Camels are subjected to a wide variety of nutritional deficiencies as they are largely dependent upon grazing desert plants. As a consequence, the syndrome of pica or depraved appetite is occasionally seen in dromedary camels. The condition is manifested as chewing or eating abnormal things such as wood, dirt, bones, stones, clothes, plastics, mud, sand, or other inanimate objects. Aim: This study was designed to investigate the clinical, ultrasonographic, and postmortem findings in dromedary camels with pica or depraved appetite. Methods: Twenty-five camels of 5 days to 15 years were examined. Owner complaints included depraved appetite, loss of body condition, regurgitation of stomach content, and partial or complete absence of feces. Symptoms described were present for a period varying between 3 days, up to 12 months. The stomach compartments and small and large intestines were scanned using ultrasonography from the right and left sides of the abdomen. Necropsy was carried out on six female and three male camels where the thoracic and abdominal organs were examined with special attention to the digestive system. Results: The affected animals had a history of gradual loss of body conditions, eating foreign objects, decreased or total absence of feces, and regurgitation of stomach content. Using ultrasound, the foreign body was imaged occluding completely or partially the intestines. Foreign bodies within the rumen could not be visualized with ultrasound. In cases where the rumen is impacted by sand, small pin-points revealing acoustic enhancement were imaged. Foreign bodies were removed from the rumen at exploratory rumenotomy (n = 11), laparotomy (n = 3), or at necropsy (n = 8) in the form of plastics, cloths, sand, mud, wool balls, robes, glasses, or even metallic objects which may be blunt or sharp. Sixteen (64%) of the camels were recovered while the remaining 9 (36%) did not survive. Conclusion: The syndrome of pica or depraved appetite is an important condition in dromedary resulting in the ingestion of objects other than normal feed. Substantial economic losses are expected as a result of this syndrome. Ultrasonography of the digestive system may help the clinician in some cases to localize of occluding foreign bodies in the intestines, while in the transabdominal scanning of the stomach is valuable only in cases of sand impaction.


Asunto(s)
Camelus , Cuerpos Extraños , Animales , Apetito , Pica , Arena , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/veterinaria
15.
Pediatr Surg Int ; 40(1): 93, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38551664

RESUMEN

PURPOSE: Inhalation of a foreign body is a real emergency in pediatric age and requires prompt diagnosis and treatment to reduce mortality. The objective of this study is to analyze clinical and radiological details, types, and localization of foreign bodies in patients conducted or to our hospital with suspected inhalation. METHODS: We conducted a retrospective analysis of all cases of foreign body inhalation admitted to our Pediatric Emergency Room between January 2009 and June 2022. RESULTS: 171 patients were included in the study. In 83 patients, the FB was detected. The mean age of presentation was 2.3 years (SD: ± 2). Cough (73%) and unilateral reduced breath sound (51%) were the most common clinical symptom and clinical sign. The most frequent localization was the right main bronchus (43%). The foreign bodies retrieved were vegetable (83%), of which peanut was the most common. Chest radiographs were normal in 25%. The mean duration of hospitalization was 5 days (± 2.9). Complications such as pneumothorax were seen in two cases. CONCLUSIONS: Foreign body inhalation represents a true pediatric emergency and still a challenge in clinical practice. The best way to manage it is an early diagnosis and removal by fully trained staff.


Asunto(s)
Broncoscopía , Cuerpos Extraños , Niño , Humanos , Lactante , Preescolar , Estudios Retrospectivos , Atención Terciaria de Salud , Aspiración Respiratoria/diagnóstico , Aspiración Respiratoria/terapia , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/cirugía
16.
Int J Pediatr Otorhinolaryngol ; 179: 111902, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38479070

RESUMEN

INTRODUCTION: Button battery (BB) ingestion injuries are a devastating and preventable event within the pediatric population. Efforts to reduce the prevalence of esophageal button battery ingestion injuries include primary preventative measures. It is integral to assess the public's baseline knowledge about BB injuries to tailor future primary prevention efforts. METHODS: This is a crowdsourcing survey-based study. Participants were notified through our institution's Twitter and Instagram accounts. RESULTS: There were 930 completed survey responses from May to June 2022. The survey found that 87% (791/910) knew that swallowing a BB could cause injury and 71% knew that it could cause death (642/905). Eight-five percent of respondents did not know what signs and symptoms to look for after BB ingestion, only 30% (99/340) of healthcare professionals felt they would know. Only 10.1% (94/930) of participants knew to give children over 12 months old honey after suspected BB ingestion. Thirty-four percent (311/930) knew that complications could still occur even after BB were removed. Seventy-seven percent (719/930) knew that a dead BB could cause injury but only 17% knew the correct way to dispose of a dead button battery (158/930). Only 8% (72/930) of participants were knew that wrapping dead BB in tape could potentially prevent injury. CONCLUSION: The current study reveals gaps in the public's understanding of BB injury including: the presentation of BB injuries; the delayed harm of BB impactions; management and mitigation strategies, and BB disposal methods. This survey provided imperative insights to help guide future education and primary prevention initiatives.


Asunto(s)
Enfermedades del Esófago , Cuerpos Extraños , Medios de Comunicación Sociales , Niño , Humanos , Lactante , Estudios Transversales , Cuerpos Extraños/epidemiología , Cuerpos Extraños/etiología , Cuerpos Extraños/prevención & control , Enfermedades del Esófago/complicaciones , Suministros de Energía Eléctrica , Ingestión de Alimentos
17.
J Emerg Med ; 66(4): e538-e539, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38485573
18.
Surg Laparosc Endosc Percutan Tech ; 34(2): 206-221, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38450728

RESUMEN

BACKGROUND: Foreign bodies within the pleura and pancreas are infrequent, and the approaches to their treatment still a subject of debate. There is limited knowledge particularly regarding glass foreign bodies. METHODS: We present a case involving large glass splinters in the pleura and pancreas, with an unknown entry point. In addition, a systematic review was conducted to explore entry hypotheses and management options. RESULTS: In addition to our case, our review uncovered eight incidents of intrapleural glass, and another eight cases of glass in other intrathoracic areas. The fragments entered the body through impalement (81%), migrated through the diaphragm after impalement (6%), or caused transesophageal perforation (19%) following ingestion. Eight instances of glass inside the abdominal cavity were documented, with seven resulting from impalement injuries and one from transintestinal migration. There were no recorded instances of glass being discovered within the pancreas. Among the 41 nonglass intrapancreatic foreign bodies found, sewing needles (34%) and fish bones (46%) were the most common; following ingestion, they had migrated through either a transgastric or transduodenal perforation. In all these cases, how the foreign bodies were introduced was often poorly recalled by the patient. Many nonglass foreign bodies tend to become encapsulated by fibrous tissue, rendering them inert, though this is less common with glass. Glass has been reported to migrate through various tissues and cavities, sometimes with a significant delay spanning even decades. There are cases of intrapleural migration of glass causing hemothorax, pneumothorax, and heart and major blood vessels injury. For intrapleural glass fragment management, thoracoscopy proved to be effective in 5 reported cases, in addition to our patient. Most intrapancreatic nonglass foreign bodies tend to trigger pancreatitis and abscess formation, necessitating management ranging from laparoscopic procedures to subtotal pancreatectomy. There have been only four documented cases of intrapancreatic needles that remained asymptomatic with conservative management. There is no direct guidance from the existing literature regarding management of intrapancreatic glass foreign bodies. Consequently, our patient is under observation with regular follow-ups and has remained asymptomatic for the past 2 years. CONCLUSIONS: Glass foreign bodies in the pleura are rare, and our report of an intrapancreatic glass fragment is the first of its kind. Impalement is the most likely method of introduction. As glass has significant migration and an ensuing complication potential, preventive removal of intrapleural loose glass should be considered. However, intrapancreatic glass fragment management remains uncertain.


Asunto(s)
Cuerpos Extraños , Pleura , Humanos , Pleura/cirugía , Cuerpos Extraños/cirugía , Páncreas/cirugía , Toracoscopía/efectos adversos , Pancreatectomía/efectos adversos
19.
Radiographics ; 44(4): e230160, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38483831

RESUMEN

The epicardial space (ES) is the anatomic region located between the myocardium and the pericardium. This space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves. The epicardial fat represents the main component of the ES. This fat deposit has been a focus of research in recent years owing to its properties and relationship with coronary gossypiboma plaque and atrial fibrillation. Although this region is sometimes forgotten, a broad spectrum of lesions can be found in the ES and can be divided into neoplastic and nonneoplastic categories. Epicardial neoplastic lesions include lipoma, paraganglioma, metastases, angiosarcoma, and lymphoma. Epicardial nonneoplastic lesions encompass inflammatory infiltrative disorders, such as immunoglobulin G4-related disease and Erdheim-Chester disease, along with hydatidosis, abscesses, coronary abnormalities, pseudoaneurysms, hematoma, lipomatosis, and gossypiboma. Initial imaging of epicardial lesions may be performed with echocardiography, but CT and cardiac MRI are the best imaging modalities to help characterize epicardial lesions. Due to the nonspecific onset of signs and symptoms, the clinical history of a patient can play a crucial role in the diagnosis. A history of malignancy, multisystem diseases, prior trauma, myocardial infarction, or cardiac surgery can help narrow the differential diagnosis. The diagnostic approach to epicardial lesions should be made on the basis of the specific location, characteristic imaging features, and clinical background. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.


Asunto(s)
Tejido Adiposo , Cuerpos Extraños , Humanos , Tejido Adiposo/patología , Pericardio/diagnóstico por imagen , Miocardio , Ecocardiografía/métodos
20.
J Neural Eng ; 21(2)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38484397

RESUMEN

Objective.This study aims to characterize the time course of impedance, a crucial electrophysiological property of brain tissue, in the human thalamus (THL), amygdala-hippocampus, and posterior hippocampus over an extended period.Approach.Impedance was periodically sampled every 5-15 min over several months in five subjects with drug-resistant epilepsy using an investigational neuromodulation device. Initially, we employed descriptive piecewise and continuous mathematical models to characterize the impedance response for approximately three weeks post-electrode implantation. We then explored the temporal dynamics of impedance during periods when electrical stimulation was temporarily halted, observing a monotonic increase (rebound) in impedance before it stabilized at a higher value. Lastly, we assessed the stability of amplitude and phase over the 24 h impedance cycle throughout the multi-month recording.Main results.Immediately post-implantation, the impedance decreased, reaching a minimum value in all brain regions within approximately two days, and then increased monotonically over about 14 d to a stable value. The models accounted for the variance in short-term impedance changes. Notably, the minimum impedance of the THL in the most epileptogenic hemisphere was significantly lower than in other regions. During the gaps in electrical stimulation, the impedance rebound decreased over time and stabilized around 200 days post-implant, likely indicative of the foreign body response and fibrous tissue encapsulation around the electrodes. The amplitude and phase of the 24 h impedance oscillation remained stable throughout the multi-month recording, with circadian variation in impedance dominating the long-term measures.Significance.Our findings illustrate the complex temporal dynamics of impedance in implanted electrodes and the impact of electrical stimulation. We discuss these dynamics in the context of the known biological foreign body response of the brain to implanted electrodes. The data suggest that the temporal dynamics of impedance are dependent on the anatomical location and tissue epileptogenicity. These insights may offer additional guidance for the delivery of therapeutic stimulation at various time points post-implantation for neuromodulation therapy.


Asunto(s)
Estimulación Encefálica Profunda , Cuerpos Extraños , Humanos , Impedancia Eléctrica , Encéfalo/fisiología , Electrodos Implantados , Estimulación Encefálica Profunda/métodos
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