Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 423
Filtrar
1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3432-3435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018741

RESUMO

Many advances have been made with imaging of implanted neural devices; however, the ability to image whole nerve samples remains limited. Further, few imaging modalities are well suited for visualizing both whole devices in vivo and individual microelectrodes within a nerve. In this study, we used micro-computed tomography (micro-CT) to evaluate Wireless Floating Microelectrode Arrays (WMFAs) implanted in rat sciatic nerve at the level of whole devices and individual electrodes. WFMAs were also used to track selective recruitment of plantar flexion and dorsiflexion of the rear paw, which was achieved by each implanted device (n=6) during chronic implantation. Evoked limb motion was correlated to end-of-study assessments using micro-CT to visualize electrode locations within the fascicular structure of the sciatic nerve. Results of this study show that micro-CT imaging can provide valuable assessments of microelectrode arrays implanted in peripheral nerves for both whole devices visualized in vivo and individual electrodes visualized in whole nerve tissue samples.Clinical relevance- This work informs the use of micro-computed tomography as a tool for correlating neural device performance with physical attributes of the implant location.


Assuntos
Nervo Isquiático , Animais , Eletrodos Implantados , Microeletrodos , Ratos , Nervo Isquiático/diagnóstico por imagem , Microtomografia por Raio-X
2.
PLoS Genet ; 16(6): e1008841, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544203

RESUMO

Hypomyelination, a neurological condition characterized by decreased production of myelin sheets by glial cells, often has no known etiology. Elucidating the genetic causes of hypomyelination provides a better understanding of myelination, as well as means to diagnose, council, and treat patients. Here, we present evidence that YIPPEE LIKE 3 (YPEL3), a gene whose developmental role was previously unknown, is required for central and peripheral glial cell development. We identified a child with a constellation of clinical features including cerebral hypomyelination, abnormal peripheral nerve conduction, hypotonia, areflexia, and hypertrophic peripheral nerves. Exome and genome sequencing revealed a de novo mutation that creates a frameshift in the open reading frame of YPEL3, leading to an early stop codon. We used zebrafish as a model system to validate that YPEL3 mutations are causative of neuropathy. We found that ypel3 is expressed in the zebrafish central and peripheral nervous system. Using CRISPR/Cas9 technology, we created zebrafish mutants carrying a genomic lesion similar to that of the patient. Our analysis revealed that Ypel3 is required for development of oligodendrocyte precursor cells, timely exit of the perineurial glial precursors from the central nervous system (CNS), formation of the perineurium, and Schwann cell maturation. Consistent with these observations, zebrafish ypel3 mutants have metabolomic signatures characteristic of oligodendrocyte and Schwann cell differentiation defects, show decreased levels of Myelin basic protein in the central and peripheral nervous system, and develop defasciculated peripheral nerves. Locomotion defects were observed in adult zebrafish ypel3 mutants. These studies demonstrate that Ypel3 is a novel gene required for perineurial cell development and glial myelination.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Bainha de Mielina/patologia , Neurogênese/genética , Proteínas Supressoras de Tumor/genética , Animais , Plexo Braquial/diagnóstico por imagem , Criança , Análise Mutacional de DNA , Modelos Animais de Doenças , Embrião não Mamífero , Feminino , Mutação da Fase de Leitura , Substância Cinzenta/diagnóstico por imagem , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/diagnóstico por imagem , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Imagem por Ressonância Magnética , Neuroglia/patologia , Oligodendroglia , Nervo Isquiático/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Sequenciamento Completo do Exoma , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
3.
Diabetes ; 69(4): 713-723, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31974140

RESUMO

Clinical studies have suggested that changes in peripheral nerve microcirculation may contribute to nerve damage in diabetic polyneuropathy (DN). High-sensitivity troponin T (hsTNT) assays have been recently shown to provide predictive values for both cardiac and peripheral microangiopathy in type 2 diabetes (T2D). This study investigated the association of sciatic nerve structural damage in 3 Tesla (3T) magnetic resonance neurography (MRN) with hsTNT and N-terminal pro-brain natriuretic peptide serum levels in patients with T2D. MRN at 3T was performed in 51 patients with T2D (23 without DN, 28 with DN) and 10 control subjects without diabetes. The sciatic nerve's fractional anisotropy (FA), a marker of structural nerve integrity, was correlated with clinical, electrophysiological, and serological data. In patients with T2D, hsTNT showed a negative correlation with the sciatic nerve's FA (r = -0.52, P < 0.001), with a closer correlation in DN patients (r = -0.66, P < 0.001). hsTNT further correlated positively with the neuropathy disability score (r = 0.39, P = 0.005). Negative correlations were found with sural nerve conduction velocities (NCVs) (r = -0.65, P < 0.001) and tibial NCVs (r = -0.44, P = 0.002) and amplitudes (r = -0.53, P < 0.001). This study is the first to show that hsTNT is a potential indicator for structural nerve damage in T2D. Our results indirectly support the hypothesis that microangiopathy contributes to structural nerve damage in T2D.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico por imagem , Angiopatias Diabéticas/diagnóstico , Neuropatias Diabéticas/diagnóstico , Imagem por Ressonância Magnética/métodos , Nervo Isquiático/diagnóstico por imagem , Troponina T/sangue , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas/sangue , Angiopatias Diabéticas/diagnóstico por imagem , Neuropatias Diabéticas/sangue , Neuropatias Diabéticas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Anesthesiology ; 132(4): 854-866, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31996555

RESUMO

BACKGROUND: The basic perineural catheter design has changed minimally since inception, with the catheter introduced through or over a straight needle. The U.S. Food and Drug Administration recently cleared a novel perineural catheter design comprising a catheter attached to the back of a suture-shaped needle that is inserted, advanced along the arc of its curvature pulling the catheter past the target nerve, and then exited through the skin in a second location. The authors hypothesized that analgesia would be noninferior using the new versus traditional catheter design in the first two days after painful foot/ankle surgery with a primary outcome of average pain measured with the Numeric Rating Scale. METHODS: Subjects undergoing painful foot or ankle surgery with a continuous supraparaneural popliteal-sciatic nerve block 5 cm proximal to the bifurcation were randomized to either a suture-type or through-the-needle catheter and subsequent 3-day 0.2% ropivacaine infusion (basal 6 ml/h, bolus 4 ml, lockout 30 min). Subjects received daily follow-up for the first four days after surgery, including assessment for evidence of malfunction or dislodgement of the catheters. RESULTS: During the first two postoperative days the mean ± SD average pain scores were lower in subjects with the suture-catheter (n = 35) compared with the through-the-needle (n = 35) group (2.7 ± 2.4 vs. 3.4 ± 2.4) and found to be statistically noninferior (95% CI, -1.9 to 0.6; P < 0.001). No suture-style catheter was completely dislodged (0%), whereas the tips of three (9%) traditional catheters were found outside of the skin before purposeful removal on postoperative day 3 (P = 0.239). CONCLUSIONS: Suture-type perineural catheters provided noninferior analgesia compared with traditional catheters for continuous popliteal-sciatic blocks after painful foot and ankle surgery. The new catheter design appears to be a viable alternative to traditional designs used for the past seven decades.


Assuntos
Anestesia por Condução/métodos , Bloqueio Nervoso Autônomo/métodos , Cateteres de Demora , Dor Pós-Operatória/prevenção & controle , Nervo Isquiático/diagnóstico por imagem , Técnicas de Sutura , Adulto , Idoso , Anestésicos Locais/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Dor Pós-Operatória/diagnóstico por imagem , Nervo Isquiático/cirurgia , Ultrassonografia de Intervenção/métodos
5.
World Neurosurg ; 134: e1085-e1092, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31778837

RESUMO

OBJECTIVE: We explored the diagnostic performance of ultrasound examinations in the diagnosis of piriformis syndrome (PS). METHODS: In our single-center retrospective study, 52 patients with a diagnosis of PS and 50 healthy volunteers were enrolled to undergo ultrasound examination of the piriformis and sciatic nerve. The thicknesses of the piriformis and the diameter of the sciatic nerve were measured to compare the differences between the patients with PS and healthy volunteers. The diagnostic performance of ultrasound examinations was assessed by constructing a receiver operating characteristic curve and calculating the area under the curve. RESULTS: In patients with PS, the piriformis and sciatic nerve were enlarged on the abnormal side compared with the asymptomatic side, accompanied by a decreased echo intensity and an unclear perineurium. In addition, the piriformis thickness and sciatic nerve diameter of those with PS were significantly greater than were those of the healthy volunteers. The diagnostic performance of ultrasonography was significant. The area under the receiver operating characteristic curve for piriformis thickness and sciatic nerve diameter to discriminate between the abnormal and asymptomatic sides was 0.778 and 0.871, respectively. CONCLUSION: Ultrasound examinations can assist in the clinical diagnosis of PS and have the potential to be an alternative method for the diagnosis of PS for most musculoskeletal clinicians.


Assuntos
Músculo Esquelético/diagnóstico por imagem , Síndrome do Músculo Piriforme/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Adulto , Estudos de Casos e Controles , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Tamanho do Órgão , Síndrome do Músculo Piriforme/patologia , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Nervo Isquiático/patologia , Ultrassonografia
6.
World Neurosurg ; 134: e1053-e1061, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31760186

RESUMO

OBJECTIVE: Lesions affecting the sciatic nerve (SN) can mimic lumbar radiculopathy. In patients presenting with sciatica, approximately 10% have a nondiscogenic etiology. Through neurological examination and imaging, it may be possible to confirm nondiscogenic sciatica (NDS). This study aims to present a series of 6 patients with infragluteal NDS, highlighting clinical and imaging aspects that may suggest this diagnosis. METHODS: This is a retrospective study of 6 patients treated for NDS from 2010 to 2018. The mean and median ages were 41.2 and 38.5 years, respectively, with all patients female. RESULTS: All patients presented with sciatic pain, tenderness to deep infragluteal palpation, and a positive Tinel's sign related to the SN. Four patients were referred for surgical treatment, whereas 1 underwent pharmacological therapy and 1 underwent incisional biopsy and radiotherapy. In our series, 6 different causes for NDS were diagnosed: 1 nontumorous cause: extrauterine endometriosis and 5 tumors: metastasis from rectal adenocarcinoma, low-grade sarcoma, schwannoma, high-grade sarcoma, and myxoma. CONCLUSIONS: Differentiating between discogenic and NDS can be challenging for clinicians. When patients present with sciatic pain, a Tinel's sign related to the SN elicited at the deep infragluteal region, tenderness to deep infragluteal palpation, occasionally with an SN motor deficit and imaging findings of the lumbar spine that do not justify a discogenic source, the cause should be considered nondiscogenic and they should be scheduled for magnetic resonance imaging of the gluteal and pelvic region.


Assuntos
Adenocarcinoma/secundário , Endometriose/diagnóstico por imagem , Mixoma/diagnóstico por imagem , Neurilemoma/diagnóstico por imagem , Neoplasias do Sistema Nervoso Periférico/diagnóstico por imagem , Neoplasias Retais/patologia , Sarcoma/diagnóstico por imagem , Ciática/etiologia , Adenocarcinoma/complicações , Adenocarcinoma/diagnóstico por imagem , Adulto , Endometriose/complicações , Endometriose/patologia , Feminino , Humanos , Imagem por Ressonância Magnética , Mixoma/complicações , Mixoma/patologia , Neurilemoma/complicações , Neurilemoma/patologia , Doenças do Sistema Nervoso Periférico/complicações , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Doenças do Sistema Nervoso Periférico/patologia , Neoplasias do Sistema Nervoso Periférico/complicações , Neoplasias do Sistema Nervoso Periférico/patologia , Exame Físico , Estudos Retrospectivos , Sarcoma/complicações , Sarcoma/patologia , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/patologia , Adulto Jovem
7.
Diabetes ; 69(3): 436-447, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31826867

RESUMO

Studies on magnetic resonance neurography (MRN) in diabetic polyneuropathy (DPN) have found proximal sciatic nerve lesions. The aim of this study was to evaluate the functional relevance of sciatic nerve lesions in DPN, with the expectation of correlations with the impairment of large-fiber function. Sixty-one patients with type 2 diabetes (48 with and 13 without DPN) and 12 control subjects were enrolled and underwent MRN, quantitative sensory testing, and electrophysiological examinations. There were differences in mechanical detection (Aß fibers) and mechanical pain (Aδ fibers) but not in thermal pain and thermal detection clusters (C fibers) among the groups. Lesion load correlated with lower Aα-, Aß-, and Aδ-fiber but not with C-fiber function in all participants. Patients with lower function showed a higher load of nerve lesions than patients with elevated function or no measurable deficit despite apparent DPN. Longer diabetes duration was associated with higher lesion load in patients with DPN, suggesting that nerve lesions in DPN may accumulate over time and become clinically relevant once a critical amount of nerve fascicles is affected. Moreover, MRN is an objective method for determining lower function mainly in medium and large fibers in DPN.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Neuropatias Diabéticas/diagnóstico por imagem , Condução Nervosa , Nervo Isquiático/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/etiologia , Neuropatias Diabéticas/fisiopatologia , Eletrodiagnóstico , Feminino , Hemoglobina A Glicada/metabolismo , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fibras Nervosas Mielinizadas/fisiologia , Fibras Nervosas Amielínicas/fisiologia , Nociceptividade/fisiologia , Dor/fisiopatologia , Nervo Isquiático/fisiopatologia , Índice de Gravidade de Doença , Tato/fisiologia
8.
J Radiol Case Rep ; 14(12): 1-13, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33717399

RESUMO

A 41-year-old Asian male with NF1 and bilateral sciatic plexiform neurofibromas, presented with unintentional weight loss, increasing size of a left thigh mass associated with increasing pain and radiculopathy. MRI of the left thigh demonstrated imaging features suspicious of malignant transformation. The patient had a new left lung mass, demonstrating avid FDG uptake, raising suspicion for metastasis. Surgical resection of the left thigh mass confirms malignant transformation in a preexisting sciatic plexiform neurofibroma. Diagnosis of malignant transformation in a nerve sheath tumour can be challenging. MRI remains the main preferred imaging modality in the evaluation of these tumours. Imaging features that raise suspicion for malignant transformation are discussed. Although none of these are specific for malignant transformation, studies suggest that the presence of two to four of these features should prompt further investigations.


Assuntos
Neurofibroma Plexiforme/patologia , Neurofibromatose 1/patologia , Nervo Isquiático/patologia , Neoplasias da Coluna Vertebral/patologia , Adulto , Humanos , Imagem por Ressonância Magnética , Masculino , Neurofibroma Plexiforme/diagnóstico por imagem , Neurofibromatose 1/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Nervo Isquiático/diagnóstico por imagem , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X
9.
Pan Afr Med J ; 37: 233, 2020.
Artigo em Francês | MEDLINE | ID: mdl-33552351

RESUMO

Schwannomas of the sciatic nerve are rare tumors. They are mainly manifested by sciatic neuralgia rather than by sensory-motor deficits. We report the case of a 30-year-old female patient with right buttock pain for 1 year. Palpation revealed a positive Tinel sign. A magnetic resonance imaging (MRI) was performed which objectified a roughly rounded, regular mass of 2 cm in diameter in intimate contact with the large sciatic nerve. A complete excision of the tumor was carried out. This excision allowed the pain to disappear and the pathology examination concluded with a plexiform schwannoma.


Assuntos
Neurilemoma/diagnóstico por imagem , Neoplasias do Sistema Nervoso Periférico/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Adulto , Feminino , Humanos , Imagem por Ressonância Magnética , Neurilemoma/patologia , Neurilemoma/cirurgia , Neoplasias do Sistema Nervoso Periférico/patologia , Neoplasias do Sistema Nervoso Periférico/cirurgia , Nervo Isquiático/patologia
10.
Kathmandu Univ Med J (KUMJ) ; 18(70): 176-180, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33594026

RESUMO

Background Sciatic nerve block used for various surgeries below knee and for maintenance of analgesia demonstrates wide variability regarding its bifurcation into tibial and common peroneal nerves, frequently accounting for incomplete nerve blocks. Objective To determine the variation of sciatic nerve bifurcation among Nepalese volunteers. Method This cross sectional study was conducted in the Department of Anesthesiology of Kathmandu Medical College Teaching Hospital from March to May 2019, where 110 healthy volunteers underwent ultrasonography of sciatic nerve starting from popliteal fossa to its bifurcation. The distance between the bifurcation of sciatic nerve from popliteal crease and depth of the nerve at that point from the skin were measured. Result The mean distance at which sciatic nerve bifurcated from the popliteal crease was 5.42 ± 1.37 cm. Most commonly, the sciatic nerve bifurcated at a distance of 5-7 cm from the popliteal crease in 110 limbs (50.45%). However, in 80 limbs (36.69%), the bifurcation was found at less than 5 cm from the popliteal crease. The depth of the nerve from the skin at the point of bifurcation was 1.72 ± 0.54 cm, with results showing it was deeper in females compared to males (p value < 0.001). Conclusion This study showed that though the distance of sciatic nerve bifurcation from the popliteal crease in our study group was coherent with the published literature of 5-12 cm; many volunteers also had this bifurcation at distances less than 5 cm. Females showed nerves to be deeper at the point of bifurcation than males.


Assuntos
Bloqueio Nervoso , Nervo Isquiático , Estudos Transversais , Feminino , Humanos , Masculino , Nervo Fibular , Nervo Isquiático/diagnóstico por imagem , Voluntários
11.
J Comput Assist Tomogr ; 43(6): 953-957, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31738201

RESUMO

PURPOSE: Compression of the sciatic nerve in its path along the piriformis muscle can produce sciatica-like symptoms. There are 6 predominant types of sciatic nerve variations with type 1 being the most common (84.2%), followed by type 2 (13.9%). However, there is scarce literature on the prevalence of sciatic nerve variation in those diagnosed with sciatica. MATERIALS AND METHODS: The charts of 95 patients clinically diagnosed with sciatica who had a magnetic resonance imaging of the pelvis/hip were retrospectively studied. All patients had T1-weighted axial, coronal, and sagittal images. Magnetic resonance imagings were interpreted separately by 2 board-certified fellowship-trained musculoskeletal radiologists to identify the sciatic nerve variant. RESULTS: Seven cases were excluded because of inadequate imaging. Of the remaining 88 patients, 5 had bilateral sciatica resulting in a sample size of 93 limbs. Fifty-two (55.9%) had type 1 sciatic nerve anatomy, 39 (41.9%) had type 2, and 2 (2.2%) had type 3. The proportions of type 1 and 2 variations were significantly different from the normal distribution (P < 0.001), whereas type 3, 4, 5, and 6 variants were not (P = 1.00). CONCLUSIONS: There is strong statistical significance regarding the relationship between sciatic nerve variation and the clinical diagnosis of sciatica. Preoperative magnetic resonance imaging can be considered in sciatica patients to prevent iatrogenic injury in pelvic surgery.


Assuntos
Síndrome do Músculo Piriforme/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Nervo Isquiático/diagnóstico por imagem , Ciática/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Estudos Retrospectivos , Nervo Isquiático/patologia , Tíbia/diagnóstico por imagem , Tíbia/inervação
12.
J Comput Assist Tomogr ; 43(6): 976-980, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31688247

RESUMO

Endometriosis (EN) is a common gynecological condition characterized by the presence of functional endometrium located outside the uterine cavity. Sciatic nerve (SN) is rarely affected by EN. Magnetic resonance imaging allows a direct visualization of the spinal and SN, and it is the modality of choice for the study of SN involvement in extrapelvic EN. We report a case of an endometrioma located in the right SN with a systematic review of the literature.


Assuntos
Endometriose/diagnóstico por imagem , Nervo Isquiático/patologia , Ciática/diagnóstico por imagem , Adulto , Endometriose/complicações , Endometriose/cirurgia , Feminino , Humanos , Laparoscopia , Imagem por Ressonância Magnética/métodos , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/cirurgia , Ciática/etiologia , Ciática/cirurgia , Resultado do Tratamento
13.
Pan Afr Med J ; 33: 242, 2019.
Artigo em Francês | MEDLINE | ID: mdl-31692794

RESUMO

The sciatic nerve is the terminal branch of the sacral plexus. Sciatalgia is a nerve root pain. In most cases, sciatica originates from degenerative disc disease. Tumor involving the sciatic nerve is extremely rare. We here report the case of a 33-year old patient with nerve tumor detected on MRI performed for drug-resistant sciatica. Tumor involving the sciatic nerve is rare and diagnosis is difficult. MRI data are crucial for establishing an effective surgical approach.


Assuntos
Imagem por Ressonância Magnética/métodos , Neurilemoma/diagnóstico por imagem , Neurofibroma/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Nervo Isquiático/patologia , Ciática/diagnóstico
14.
BMC Musculoskelet Disord ; 20(1): 438, 2019 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-31564252

RESUMO

BACKGROUND: The aim of this study was to find out whether the shear wave elastography (SWE) findings of patients with unilateral lumbar disc herniation (LDH) were related to clinical characteristics. METHODS: For this purpose, the study group included patients (N = 20; 13 male, 7 female) with complaints of unilateral sciatica, with foraminal stenosis caused by one level of LDH (L4-L5 or L5-S1). An gender-and age-matched control group (N = 27; 16 male, 11 female) was included. All the patients were examined on both the axial and longitudinal planes bilaterally at the same level using a convex array probe (1- 6 MHz, Supersonic Imagine, Aix en Provence, France). RESULTS: The sciatic nerve stiffness measured on longitudinal planes of the affected side was significantly higher than unaffected side (p < 0.001) and the control group (P < 0.05). Furthermore, the symptom duration of unilateral LDH is positively correlated with the stiffness the sciatic nerve (r = 0.52, p = 0.019). CONCLUSION: According to these findings, ultrasound imaging can be considered as a useful tool to detect changes in the sciatic nerve due to disc herniation. This technique will have a promising prospect for many patients with unilateral LDH in monitoring stiffness during rehabilitation and before or after surgery.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Ciática/diagnóstico por imagem , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/terapia , Vértebras Lombares/diagnóstico por imagem , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Ciática/etiologia , Ciática/terapia , Resultado do Tratamento
15.
Sci Rep ; 9(1): 12641, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477751

RESUMO

Human peripheral nerves hold the potential to regenerate after injuries; however, whether a successful axonal regrowth was achieved can be elucidated only months after injury by assessing function. The axolotl salamander is a regenerative model where nerves always regenerate quickly and fully after all types of injury. Here, de- and regeneration of the axolotl sciatic nerve were investigated in a single and double injury model by label-free multiphoton imaging in comparison to functional recovery. We used coherent anti-Stokes Raman scattering to visualize myelin fragmentation and axonal regeneration. The presence of axons at the lesion site corresponded to onset of functional recovery in both lesion models. In addition, we detected axonal regrowth later in the double injury model in agreement with a higher severity of injury. Moreover, endogenous two-photon excited fluorescence visualized macrophages and revealed a similar timecourse of inflammation in both injury models, which did not correlate with functional recovery. Finally, using the same techniques, axonal structure and status of myelin were visualized in vivo after sciatic nerve injury. Label-free imaging is a new experimental approach that provides mechanistic insights in animal models, with the potential to be used in the future for investigation of regeneration after nerve injuries in humans.


Assuntos
Ambystoma mexicanum/fisiologia , Imageamento Tridimensional , Regeneração Nervosa/fisiologia , Nervos Periféricos/fisiologia , Recuperação de Função Fisiológica/fisiologia , Coloração e Rotulagem , Animais , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Traumatismos dos Nervos Periféricos/patologia , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/lesões , Nervo Isquiático/patologia , Processamento de Sinais Assistido por Computador , Análise Espectral Raman , Fatores de Tempo
16.
J Vis Exp ; (150)2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31524869

RESUMO

Single-fiber recording has been a classical and effective electrophysiological technique over the last few decades because of its specific application for nerve fibers in the central and peripheral nervous systems. This method is particularly applicable to dorsal root ganglia (DRG), which are primary sensory neurons that exhibit a pseudo-unipolar structure of nervous processes. The patterns and features of the action potentials passed along axons are recordable in these neurons. The present study uses in vivo single-fiber recordings to observe the conduction failure of sciatic nerves in complete Freund's adjuvant (CFA)-treated rats. As the underlying mechanism cannot be studied using in vivo single-fiber recordings, patch-clamp-recordings of DRG neurons are performed on preparations of intact DRG with the attached sciatic nerve. These recordings reveal a positive correlation between conduction failure and the rising slope of the after-hyperpolarization potential (AHP) of DRG neurons in CFA-treated animals. The protocol for in vivo single fiber-recordings allows the classification of nerve fibers via the measurement of conduction velocity and monitoring of abnormal conditions in nerve fibers in certain diseases. Intact DRG with attached peripheral nerve allows observation of the activity of DRG neurons in most physiological conditions. Conclusively, single-fiber recording combined with electrophysiological recording of intact DRGs is an effective method to examine the role of conduction failure during the analgesic process.


Assuntos
Gânglios Espinais/diagnóstico por imagem , Gânglios Espinais/fisiopatologia , Fibras Nervosas Amielínicas/fisiologia , Condução Nervosa/fisiologia , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/fisiopatologia , Animais , Adjuvante de Freund/farmacologia , Gânglios Espinais/efeitos dos fármacos , Masculino , Fibras Nervosas Amielínicas/efeitos dos fármacos , Condução Nervosa/efeitos dos fármacos , Ratos Sprague-Dawley , Nervo Isquiático/efeitos dos fármacos
17.
Pathologica ; 111(2): 67-69, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31388198

RESUMO

Peripheral nerve mucoid degeneration (PNMD) is a rare non-neoplastic degenerative condition characterized by endoneural deposit of mucoid matrix. Herein, we report a case of PNMD involving the sciatic nerve with preoperative features, surgical treatment and pathological findings.


Assuntos
Degeneração Neural/diagnóstico por imagem , Degeneração Neural/cirurgia , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Doenças do Sistema Nervoso Periférico/cirurgia , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/cirurgia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Nervo Isquiático/patologia
18.
Anaesthesist ; 68(9): 615-617, 2019 09.
Artigo em Alemão | MEDLINE | ID: mdl-31463544

RESUMO

Sonographically controlled blockade of the distal sciatic nerve is usually performed by placing the ultrasound probe on the dorsal side of the thigh. This requires positioning maneuvers (prone or side positioning) of the patient as well as additional assistance. In order to avoid these positioning maneuvers, a positioning aid with integrated ultrasound probe holder has been developed and its practicability was examined on patients with lower limb surgery. The sonographically controlled block of the sciatic nerve was performed with the patient under general anesthesia and in a supine position with the help of the new positioning aid with an integrated ultrasound probe holder. A total of >100 patients were treated, who underwent elective lower leg, ankle or foot surgery with a continuous blockade of the distal sciatic nerve using catheters for postoperative analgesia. The advantages are easy performance, hands-free needle movement and catheter placement. The disadvantages might be the need for in-plane catheter placement and a fixed ultrasound angle.


Assuntos
Bloqueio Nervoso/instrumentação , Bloqueio Nervoso/métodos , Nervo Isquiático/efeitos dos fármacos , Ultrassonografia de Intervenção/instrumentação , Ultrassonografia de Intervenção/métodos , Anestesia Geral , Humanos , Nervo Isquiático/diagnóstico por imagem
19.
World Neurosurg ; 129: e761-e766, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31203072

RESUMO

INTRODUCTION: The natural history of growth and radiologic progression of neuromuscular choristomas (NMCs) remain unknown. The purpose of this study was to describe the radiologic growth pattern of NMCs and to determine how the pattern of growth relates to clinical progression. METHODS: A retrospective review was performed for patients with a confirmed diagnosis of NMC and at least 2 years of radiologic (magnetic resonance imaging [MRI]) follow-up. Medical records, including physical examinations and radiologic studies, were reviewed in detail. The NMC length and transverse dimensions were compared between serial MRI examinations. RESULTS: Eleven patients with a mean radiologic follow-up time of 5.6 years (range 2-19 years) were identified. Motor deficits occurred in 10 patients (90%), sensory deficits in 5 patients (45%), and neuropathic pain in 4 (36%) patients. Eight patients (73%) presented with manifestations of limb undergrowth, 2 (18%) with congenital hip dysplasia, and 1 with a cavus foot deformity. Progression of motor and sensory deficits was observed in 5 (45%) and 1 (9%) patients, respectively. The maximal length and height of the NMC was significantly (P < 0.05) longer (initial 218 ± 118 mm vs. follow-up 270 ± 135 mm) and larger (20 ± 10 mm vs. 24 ± 14 mm) on the follow-up scan. MRI demonstrated abnormalities that were in continuity along the longitudinal extent of the NMC. CONCLUSIONS: According to this small but relatively long-term follow-up cohort, the growth pattern of this lesion is slow but progressive. We found a longitudinal continuity pattern of growth in all MRI scans, often spanning a great distance.


Assuntos
Plexo Braquial/diagnóstico por imagem , Coristoma/diagnóstico por imagem , Músculo Esquelético , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Nervo Isquiático/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
20.
Clin Anat ; 32(6): 836-850, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31125132

RESUMO

In pediatric patients, peripheral anesthetic blockade of the sciatic nerve is useful for postoperative pain relief after orthopedic procedures of the lower limb. The identification of the sciatic and its branches relative to the surrounding anatomical structures of the knee significantly contribute to the successful nerve blockade. However, reports have demonstrated complications arising from the inadequate and inconsistent understanding of the anatomy of the nerves in the knee region. In addition, the paucity of information regarding the location of the nerves of the knee throughout the pediatric development needs to be addressed in order for peripheral nerve blockades to become more readily used among the pediatric population. This clinical imaging study therefore aimed to document and analyze the relative morphometric relationship of the nerves in the knee region throughout the different stages of pediatric development. The locations of the sciatic, tibial, and common fibular nerves were measured in relation to relevant anatomical structures in 142 pediatric magnetic resonance imaging and computed tomography. A strong correlation was found between age and the distance from the common fibular nerve to the semitendinosus muscle, and thus can be used to predict stature. Significant differences were found between males and females, specifically after puberty, suggesting that sexual dimorphism emerges more distinctively at puberty. In order to predict the location of the nerves at the popliteal fossa, a regression formula using the patient's age and bicondylar width was created. These finding may have significant implications for popliteal approach of the sciatic nerve blockade in pediatric patients. Clin. Anat. 32:836-850, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Bloqueio Nervoso Autônomo/métodos , Articulação do Joelho/anatomia & histologia , Joelho/anatomia & histologia , Nervo Isquiático/anatomia & histologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Joelho/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Imagem por Ressonância Magnética , Masculino , Estudos Retrospectivos , Nervo Isquiático/diagnóstico por imagem , Fatores Sexuais , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...