Descrição do plexo braquial do cachorro-do-mato (Cerdocyon thous Linnaeus, 1766)

The Cerdocyon thous is a canid that has a wide distribution in South America and, besides some general aspects, its morphology is little known in the literature, especially regarding the nervous system. With the aim of elucidating the anatomical composition of brachial plexus, we studied three male specimens from Paragominas-PA, donated to the Morphological Laboratory of Animal Research (LaPMA), Federal Rural University of Amazonia (UFRA), after death by trampling. The animals were fixed in an aqueous solution of 10% formaldehyde for bilateral dissection of the origin of the brachial plexus. The brachial plexus of C. thous is derived from the last three cervical nerves and the first thoracic nerve (C6-T1). The main nerves that compose it, with their respective origins were the suprascapular nerve, subscapular nerve and musculocutaneous nerve (C6-C7), axillary nerve (C7-C8), radial nerve (C7-T1 and C7-C8), median nerve, ulnar nerve, thoracodorsal and thoracic lateral nerve (C8-T1). We conclude that the brachial plexus of C. thous is similar to that described for the domestic dogs, showing small differences in the composition of some nerves.

Management of desmoid-type fibromatosis involving peripheral nerves

Desmoid-type fibromatosis is an uncommon and aggressive neoplasia, associated with a high rate of recurrence. It is characterized by an infiltrative but benign fibroblastic proliferation occurring within the deep soft tissues. There is no consensus about the treatment of those tumors. We present a surgical series of four cases, involving the brachial plexus (two cases), the median nerve and the medial brachial cutaneous nerve. Except for the last case, they were submitted to multiple surgical procedures and showed repeated recurrences. The diagnosis, the different ways of treatment and the prognosis of these tumoral lesions are discussed. Our results support the indication of radical surgery followed by radiotherapy as probably one of the best ways to treat those controversial lesions.

Differential cellular FGF-2 upregulation in the rat facial nucleus following axotomy, functional electrical stimulation and corticosterone: a possible therapeutic target to Bell's palsy

Abstract Background The etiology of Bell's palsy can vary but anterograde axonal degeneration may delay spontaneous functional recovery leading the necessity of therapeutic interventions. Corticotherapy and/or complementary rehabilitation interventions have been employed. Thus the natural history of the disease reports to a neurotrophic resistance of adult facial motoneurons leading a favorable evolution however the related molecular mechanisms that might be therapeutically addressed in the resistant cases are not known. Fibroblast growth factor-2 (FGF-2) pathway signaling is a potential candidate for therapeutic development because its role on wound repair and autocrine/paracrine trophic mechanisms in the lesioned nervous system. Methods Adult rats received unilateral facial nerve crush, transection with amputation of nerve branches, or sham operation. Other group of unlesioned rats received a daily functional electrical stimulation in the levator labii superioris muscle (1 mA, 30 Hz, square wave) or systemic corticosterone (10 mgkg-1). Animals were sacrificed seven days later. Results Crush and transection lesions promoted no changes in the number of neurons but increased the neurofilament in the neuronal neuropil of axotomized facial nuclei. Axotomy also elevated the number of GFAP astrocytes (143% after crush; 277% after transection) and nuclear FGF-2 (57% after transection) in astrocytes (confirmed by two-color immunoperoxidase) in the ipsilateral facial nucleus. Image analysis reveled that a seven days functional electrical stimulation or corticosterone led to elevations of FGF-2 in the cytoplasm of neurons and in the nucleus of reactive astrocytes, respectively, without astrocytic reaction. Conclusion FGF-2 may exert paracrine/autocrine trophic actions in the facial nucleus and may be relevant as a therapeutic target to Bell's palsy.

Resultado da neurotização do nervo ulnar para o músculo bíceps braquial na lesão do plexo braquial

OBJETIVO: Avaliar de forma crítica os fatores que influenciam os resultados da neurotização do nervo ulnar no ramo motor do músculo bíceps braquial, visando a restauração da flexão do cotovelo em pacientes com lesão do plexo braquial. MÉTODOS: 19 pacientes, 18 homens e uma mulher, com idade média de 28,7 anos foram avaliados entre fevereiro de 2003 e maio de 2007. Oito pacientes apresentavam lesão das raízes C5-C6 e 11, das raízes C5-C6-C7. O intervalo de tempo médio entre a injúria e o tratamento cirúrgico foi 7,5 meses. Quatro pacientes apresentavam fraturas cervicais associadas à lesão do plexo braquial. O seguimento pós-operatório foi de 15,7 meses. RESULTADO: Oito pacientes recuperaram força de flexão do cotovelo MRC grau 4; dois, MRC grau 3 e nove, MRC < 3. Não houve prejuízo da função prévia do nervo ulnar. CONCLUSÃO: Os resultados da cirurgia de neurotização do nervo ulnar no ramo motor no músculo bíceps braquial são dependentes: do intervalo decorrido entre a lesão do plexo e o tratamento cirúrgico, da presença de fraturas associadas da coluna cervical e côndilo occipital, da função residual das raízes de C8-T1 após o trauma e do acometimento da raiz de C7. Sinais de reinervação manifestados até 3 meses no pós cirúrgico mostram melhores resultados ao longo prazo. Nível de Evidência: IV, Série de Casos.

The effect of shoulder variation on IMRT and SmartArc for Head and Neck Cancer

Purpose: First, to determine an average and maximum displacement of the shoulder relative to isocenter over the course of treatment. Second, to establish the dosimetric effect of shoulder displacements relative to correct isocenter alignment on the dose delivered to the target and the surrounding structures for head and neck cancer patients. Method and Materials: The frequency of shoulder shifts of various magnitudes relative to isocenter was assessed for 4 patients using image registration software. The location of the center of the right and left humeral head relative to isocenter (usually C2) was found daily from CT on rails scans, and was compared to the location of the humeral heads relative to isocenter on the initial simulation CT. Three Baseline head and neck IMRT and SmartArc plans were generated in Pinnacle based on simulation CTs. The CT datasets (external contour and boney structures) were then modified to represent shifts of the shoulder (relative to isocenter) between 3 mm and 15 mm in the SI, AP, and LR directions. The initial plans were recalculated on the image sets with shifted shoulders. Results: On average, shoulder variation was 2-5 mm in each direction, although displacements of over 1 cm in the inferior and posterior directions occurred. Shoulder shifts induced perturbations in the dose distribution, although generally only for large shifts. Most substantially, large, superior shifts resulted in coverage loss by the 95% isodose line for targets in the lower neck. Inferior shifts elevated the dose to the brachial plexus by 0.6-4.1 Gy. SmartArc plans showed similar loss of target coverage as IMRT plans. Conclusions: The position of the shoulder can have an impact on target coverage and critical structure dose. Shoulder position may need to be considered for setup of head and neck patients depending on target location.

Avaliação da acurácia da ressonância magnética no diagnóstico das lesões traumáticas do plexo braquial

A lesão do plexo braquial é considerada a alteração neural mais grave das extremidades. A principal causa é o trauma de alta energia, especialmente acidentes envolvendo veículos a motor. Por este motivo, as lesões traumáticas do plexo braquial são cada vez mais frequentes. O presente estudo avaliou a acurácia da ressonância magnética (RM) no diagnóstico das lesões traumáticas do plexo braquial no adulto, utilizando o achado intraoperatório como padrão-ouro. Também foi avaliada a acurácia da neurografia pesada em difusão (neurografia DW) em relação à RM convencional e a capacidade de diferenciação dos três tipos de lesão: avulsão, ruptura e lesão em continuidade. Trinta e três pacientes com história e diagnóstico clínico de lesão traumática do plexo braquial foram prospectivamente estudados por RM. Os achados obtidos pela RM sem e com o uso da neurografia DW, e os achados de exame clínico foram comparados com os achados intraoperatórios. A análise estatística foi feita com associação de significância de 5%. Observou-se alta correlação entre a RM com neurografia DW e a cirurgia (rs=0,79), e baixa correlação entre a RM convencional e a cirurgia (rs=0,41). A correlação interobservador foi maior para a RM com neurografia DW (rs = 0,94) do que para a RM sem neurografia DW (rs = 0,75). Os resultados de sensibilidade, acurácia e valor preditivo positivo foram acima de 95% para as RM com e sem neurografia DW no estudo de todo o plexo. As especificidades foram, em geral, maiores para a neurografia DW (p < 0,05). Em relação à diferenciação dos tipos de lesão, a RM com neurografia DW apresentou altas acurácias e sensibilidades no diagnóstico da avulsão/rotura, e alta especificidade no diagnóstico da lesão em continuidade. A acurácia da RM (93,9%) foi significativamente maior que a do exame clínico (76,5%) no diagnóstico das lesões de todo o plexo braquial (p < 0,05).

Regional Anesthesia in TraumaMedicine

Regional anesthesia is an established method to provide analgesia for patients in the operating room and during the postoperative phase. While regional anesthesia offers unique advantages, as shown by the recent military experience, it is not commonly utilized in the prehospital or emergency department setting. Most often, regional anesthesia techniques for traumatized patients are first utilized in the operating room for procedural anesthesia or for postoperative pain control. While infiltration or single nerve block procedures are often used by surgeons or emergency medicine physicians in the preoperative phase, more advanced techniques such as plexus block procedures or regional catheter placements are more commonly performed by anesthesiologists for surgery or postoperative pain control. These regional techniques offer advantages over intravenous anesthesia, not just in the perioperative phase but also in the acute phase of traumatized patients and during the initial transport of injured patients. Anesthesiologists have extensive experience with regional techniques and are able to introduce regional anesthesia into settings outside the operating room and in the early treatment phases of trauma patients.

Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery

Hypersensitivity to a variety of sensory Stimuli is a feature of persistent whiplash associated disorders (WAD). However, little is known about sensory disturbances from the time Of injury until transition to either recovery or symptom persistence. Quantitative sensory testing (pressure and thermal pain thresholds, the brachial plexus provocation test), the sympathetic vasoconstrictor reflex and psychological distress (GHQ-28) were prospectively measured in 76 whiplash Subjects within 1 month of injury and then 2, 3 and 6 months post-injury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (30). Sensory and sympathetic nervous system tests were also measured in 20 control subjects. All whiplash groups demonstrated local mechanical hyperalgesia in the cervica spine at 1 month post-injury. This hyperalgesia persisted in those with moderate/severe symptoms at 6 months but resolved by 2 months in those who had recovered or reported persistent mild symptoms. Only those with persistent moderate/severe symptoms at 6 months demonstrated generalised hypersensitivity to all sensory tests. These changes Occurred within 1 month of injury and remained Unchanged throughout the Study period. Whilst no significant group differences were evident for the sympathetic vasoconstrictor response, the moderate/severe group showed a tendency for diminished sympathetic reactivity. GHQ-28 scores of the moderate/severe group were higher than those of the other two groups. The differences in GHQ-28 did not impact on any of the sensory measures. These findings suggest that those with persistent moderate/severe symptoms at 6 months display, soon after injury, generalised hypersensitivity suggestive of changes in central pain processing mechanisms. This phenomenon did not Occur in those who recover or those with persistent mild symptoms. (C) 2003 International Association for the Study of Pain. Published by Elsevier Science B.V. All rights reserved.

Characterization of acute whiplash-associated disorders

Study Design. An experimental study of motor and sensory function and psychological distress in subjects with acute whiplash injury. Objectives. To characterize acute whiplash injury in terms of motor and sensory systems dysfunction and psychological distress and to compare subjects with higher and lesser levels of pain and disability. Summary of Background Data. Motor system dysfunction, sensory hypersensitivity, and psychological distress are present in chronic whiplash associated disorders ( WAD), but little is known of such factors in the acute stage of injury. As higher levels of pain and disability in acute WAD are accepted as signs of poor outcome, further characterization of this group from those with lesser symptoms is important. Materials and Methods. Motor function ( cervical range of movement [ ROM], joint position error [JPE]; activity of the superficial neck flexors [EMG] during a test of craniocervical flexion), quantitative sensory testing ( pressure, thermal pain thresholds, and responses to the brachial plexus provocation test), and psychological distress (GHQ-28, TAMPA, IES) were measured in 80 whiplash subjects ( WAD II or III) within 1 month of injury, as were 20 control subjects. Results. Three subgroups were identified in the cohort using cluster analysis based on the Neck Disability Index: those with mild, moderate, or severe pain and disability. All whiplash groups demonstrated decreased ROM and increased EMG compared with the controls ( all P < 0.01). Only the moderate and severe groups demonstrated greater JPE and generalized hypersensitivity to all sensory tests ( all P < 0.01). The three whiplash subgroups demonstrated evidence of psychological distress, although this was greater in the moderate and severe groups. Measures of psychological distress did not impact on between group differences in motor or sensory tests. Conclusions. Acute whiplash subjects with higher levels of pain and disability were distinguished by sensory hypersensitivity to a variety of stimuli, suggestive of central nervous system sensitization occurring soon after injury. These responses occurred independently of psychological distress. These findings may be important for the differential diagnosis of acute whiplash injury and could be one reason why those with higher initial pain and disability demonstrate a poorer outcome.

Physical and psychological factors predict outcome following whiplash injury

Predictors of outcome following whiplash injury are limited to socio-demographic and symptomatic factors, which are not readily amenable to secondary and tertiary intervention. This prospective study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds, brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK, IES) were measured in 76 acute whiplash participants. The outcome measure was Neck Disability Index scores at 6 months. Stepwise regression analysis was used to predict the final NDI score. Logistic regression analyses predicted membership to one of the three groups based on final NDI scores (< 8 recovered, 10-28 mild pain and disability, > 30 moderate/severe pain and disability). Higher initial NDI score (1.007-1.12), older age (1.03-1.23), cold hyperalgesia (1.05-1.58), and acute post-traumatic stress (1.03-1.2) predicted membership to the moderate/severe group. Additional variables associated with higher NDI scores at 6 months on stepwise regression analysis were: ROM loss and diminished sympathetic reactivity. Higher initial NDI score (1.03-1.28), greater psychological distress (GHQ-28) (1.04-1.28) and decreased ROM (1.03-1.25) predicted subjects with persistent milder symptoms from those who fully recovered. These results demonstrate that both physical and psychological factors play a role in recovery or non-recovery from whiplash injury. This may assist in the development of more relevant treatment methods for acute whiplash. (c) 2004 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Physical and psychological factors maintain long-term predictive capacity post-whiplash injury

Higher initial levels of pain and disability, older age, cold hyperalgesia, impaired sympathetic vasoconstriction and moderate post-traumatic stress symptoms have been shown to be associated with poor outcome 6 months following whiplash injury. This study prospectively investigated the predictive capacity of these variables at a long-term follow-up. Sixty-five of an initial cohort of 76 acutely injured whiplash participants were followed to 2-3 years post-accident. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds and brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK and IES) were measured. The outcome measure was Neck Disability Index (NDI) scores. Participants with ongoing moderate/severe symptoms at 2-3 years continued to manifest decreased ROM, increased EMG during cranio-cervical flexion, sensory hypersensitivity and elevated levels of psychological distress when compared to recovered participants and those with milder symptoms. The latter two groups showed only persistent deficits in cervical muscle recruitment patterns. Higher initial NDI scores (OR 1.00-1.1), older age (OR 1.00-1.13), cold hyperalgesia (OR 1.1-1.13) and post-traumatic stress symptoms (OR 1.03-1.2) remained significant predictors of poor outcome at long-term follow-up (r(2) = 0.56). The robustness of these physical and psychological factors suggests that their assessment in the acute stage following whiplash injury will be important. (c) 2006 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Orthopaedic anaesthesia for upper extremity procedures in a Nigerian hospital

Background General anaesthesia and regional anaesthesia have been used successfully for upper extremity orthopaedic procedures. Despite the advantages of regional anaesthesia, there is low utilisation in Nigeria. In this study, we assessed the types of anaesthesia employed for upper extremity surgeries in our centre. Methods After obtaining approval from the institutional ethics committee, all the patients who had upper extremity surgeries from 1 January 2011 to 31 December 2012 were included in this review. Both prospective and retrospective data were gathered. The choice of anaesthesia was at the discretion of the attending anaesthetist. Results A total of 226 patients with a male-to-female ratio of 1.6:1 and median age of 35.0 (range 2 – 89) years, had orthopaedic upper extremity procedures during the study period. Sixty-three cases (27.9%) had general anaesthesia, 5 (2.2%) combined regional and general anaesthesia while 158 (69.9%) had regional blocks. The regional blocks comprised 145 (89%) different approaches to the brachial plexus and 18 (11%) local anaesthetic infiltrations. The arm was the site mostly operated upon; while supraclavicular and axillary brachial plexus blocks were performed in equal amounts. In 14 (6.2%) patients, brachial plexus blocks were performed with spinal anaesthesia because of concomitant iliac crest bone grafts. While the duration of surgery did not differ significantly, regional anaesthesia provided a significantly longer duration of anaesthesia than general anaesthesia (251 ± 70.8 min versus 141.3 ± 65.5 min; p = 0.0000001). Conclusion There is a high use of regional anaesthesia for upper extremity orthopaedic surgeries in our centre, which is a positive development in a resource limited setting.

Placement of coiled catheters into the paravertebral space

There are conflicting results with regard to the use of catheter-based techniques for continuous paravertebral block. Local anaesthetic spread within the paravertebral space is limited and the clinical effect is often variable. Discrepancies between needle tip position and final catheter position can also be problematic. The aim of this proof-of-concept study was to assess the reliability of placing a newly developed coiled catheter in human cadavers. Sixty Tuohy needles and coiled catheters were placed under ultrasound guidance, three on each side of the thoracic vertebral column in 10 human cadavers. Computed tomography was used to assess needle tip and catheter tip locations. No catheter was misplaced into the epidural, pleural or prevertebral spaces. The mean (SD) distance between catheter tips and needle tips was 8.2 (4.9) mm. The median (IQR [range]) caudo-cephalad spread of contrast dye injectate through a subset of 20 catheters was 4 (4-5[3-8]) thoracic segments. All catheters were removed without incident. Precise paravertebral catheter placement can be achieved using ultrasound-guided placement of a coiled catheter.