Base teórica A síndrome do túnel do carpo (STC) é uma lesão compressiva nervosa mais comum que afeta o nervo mediano observada na prática clínica. Existem muitas técnicas eletrofisiológicas para diagnosticar a STC, mas a maioria dispende muito tempo, é dolorosa e tem sensibilidade variada. Objetivo Avaliar a acurácia de um método eletrofisiológico de investigação da STC e correlaciona-lo com aspectos clínicos. Métodos Pacientes do ambulatório de Neurologia com critérios clínicos para STC foram submetidos a uma bateria de testes clínicos e neurofisiológicos. Primeiramente, nós aplicamos o Questionário de Síndrome do túnel do Carpo de Boston e Escala visual analógica (EVA). Após, realizamos o método eletrofisiológico convencional de avaliação sensitiva do nervo mediano e ulnar. Posteriormente, outro médico eletrofisiologista, cegado para as avaliações anteriores, realizou a técnica de estimulação simultânea dos nervos mediano e radial no polegar com registro simultâneo de ambos potenciais na região punho. Os dados foram agrupados em STC leve, moderada e grave, baseados na latência motora do nervo mediano. Resultados A latência entre picos (LEP), obtida pela técnica em estudo, foi diferente entre os grupos baseados na classificação de gravidade da STC (Bonferroni; p<0.001). A velocidade de condução nervosa sensitiva do nervo mediano, obtida através da técnica standard, apresentou também diferentes valores entre os grupos. Houve correlação entre LEP e velocidade de condução nervosa sensitiva do mediano (Sperman; r=-0.52; p<0.01), bem como entre LEP e velocidade de condução nervosa sensitiva do mediano com o desconforto causado pela STC mensurado pela Escala visual analógica (EVA). A duração e o desconforto causado pela técnica de estimulação simultânea do nervo mediano e radial estão reduzidos quando comparados com a técnica padrão (t Student; p< 0.001 para as duas comparações). Conclusão A técnica de estimulação simultânea do nervo mediano e radial é acurada, sensível, tolerável e não somente útil no diagnóstico da STC, mas também na definição da gravidade. Então, seu uso deve ser encorajado na prática clínica. / Background Carpal tunnel syndrome (CTS) is the most common nerve entrapment observed in clinical practice affecting the median nerve at the wrist level. There are many electrophysiological ways to diagnose CTS, but most of them are time consuming, painful and have variable sensitivity. Objective To evaluate the accuracy of an electophysiologic method of CTS investigation and to correlate it with clinical symptoms. Methods Patients at the clinic outpatient Neurology with CTS clinical criteria underwent a battery of clinical and neurophysiological tests. First, we applied the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and Visual analogue scale (VAS). After, we performed a standard method of analysis of the median and ulnar nerves. Posteriorly, a blinded neurophysiologist performed an orthodromic median-radial nerve simultaneous stimulation at the thumb with recording of both action potentials at the lateral aspect of the wrist. Data were grouped for mild, moderate and severe CTS, based on median motor latency. Results The interpeak latency (IPL), obtained with study technique, was different in groups based on CTS classification severity (Bonferroni. p<0.001). The median nerve conduction velocity, obtained with the standard approach, was also of different level among groups. There were correlation between IPL and median nerve conduction velocity (Sperman; r=-0.52; p<0.01), as well as, there was a significant correlation between IPL and median nerve conduction velocity with the discomfort caused by CTS and measured with VAS. However, the duration and unpleasantness caused by median-radial nerve simultaneous stimulation technique were reduced when compared to standard approach (t Student <0.001 for both comparisons). Conclusion The orthodromic median-radial nerve simultaneous stimulation technique is accurate, sensitive, tolerable and not only useful for CTS diagnosis but also for its severity assessment. Therefore, its use should be encouraged in clinical practice.

Base teórica A síndrome do túnel do carpo (STC) é uma lesão compressiva nervosa mais comum que afeta o nervo mediano observada na prática clínica. Existem muitas técnicas eletrofisiológicas para diagnosticar a STC, mas a maioria dispende muito tempo, é dolorosa e tem sensibilidade variada. Objetivo Avaliar a acurácia de um método eletrofisiológico de investigação da STC e correlaciona-lo com aspectos clínicos. Métodos Pacientes do ambulatório de Neurologia com critérios clínicos para STC foram submetidos a uma bateria de testes clínicos e neurofisiológicos. Primeiramente, nós aplicamos o Questionário de Síndrome do túnel do Carpo de Boston e Escala visual analógica (EVA). Após, realizamos o método eletrofisiológico convencional de avaliação sensitiva do nervo mediano e ulnar. Posteriormente, outro médico eletrofisiologista, cegado para as avaliações anteriores, realizou a técnica de estimulação simultânea dos nervos mediano e radial no polegar com registro simultâneo de ambos potenciais na região punho. Os dados foram agrupados em STC leve, moderada e grave, baseados na latência motora do nervo mediano. Resultados A latência entre picos (LEP), obtida pela técnica em estudo, foi diferente entre os grupos baseados na classificação de gravidade da STC (Bonferroni; p<0.001). A velocidade de condução nervosa sensitiva do nervo mediano, obtida através da técnica standard, apresentou também diferentes valores entre os grupos. Houve correlação entre LEP e velocidade de condução nervosa sensitiva do mediano (Sperman; r=-0.52; p<0.01), bem como entre LEP e velocidade de condução nervosa sensitiva do mediano com o desconforto causado pela STC mensurado pela Escala visual analógica (EVA). A duração e o desconforto causado pela técnica de estimulação simultânea do nervo mediano e radial estão reduzidos quando comparados com a técnica padrão (t Student; p< 0.001 para as duas comparações). Conclusão A técnica de estimulação simultânea do nervo mediano e radial é acurada, sensível, tolerável e não somente útil no diagnóstico da STC, mas também na definição da gravidade. Então, seu uso deve ser encorajado na prática clínica. / Background Carpal tunnel syndrome (CTS) is the most common nerve entrapment observed in clinical practice affecting the median nerve at the wrist level. There are many electrophysiological ways to diagnose CTS, but most of them are time consuming, painful and have variable sensitivity. Objective To evaluate the accuracy of an electophysiologic method of CTS investigation and to correlate it with clinical symptoms. Methods Patients at the clinic outpatient Neurology with CTS clinical criteria underwent a battery of clinical and neurophysiological tests. First, we applied the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and Visual analogue scale (VAS). After, we performed a standard method of analysis of the median and ulnar nerves. Posteriorly, a blinded neurophysiologist performed an orthodromic median-radial nerve simultaneous stimulation at the thumb with recording of both action potentials at the lateral aspect of the wrist. Data were grouped for mild, moderate and severe CTS, based on median motor latency. Results The interpeak latency (IPL), obtained with study technique, was different in groups based on CTS classification severity (Bonferroni. p<0.001). The median nerve conduction velocity, obtained with the standard approach, was also of different level among groups. There were correlation between IPL and median nerve conduction velocity (Sperman; r=-0.52; p<0.01), as well as, there was a significant correlation between IPL and median nerve conduction velocity with the discomfort caused by CTS and measured with VAS. However, the duration and unpleasantness caused by median-radial nerve simultaneous stimulation technique were reduced when compared to standard approach (t Student <0.001 for both comparisons). Conclusion The orthodromic median-radial nerve simultaneous stimulation technique is accurate, sensitive, tolerable and not only useful for CTS diagnosis but also for its severity assessment. Therefore, its use should be encouraged in clinical practice.

Base teórica A síndrome do túnel do carpo (STC) é uma lesão compressiva nervosa mais comum que afeta o nervo mediano observada na prática clínica. Existem muitas técnicas eletrofisiológicas para diagnosticar a STC, mas a maioria dispende muito tempo, é dolorosa e tem sensibilidade variada. Objetivo Avaliar a acurácia de um método eletrofisiológico de investigação da STC e correlaciona-lo com aspectos clínicos. Métodos Pacientes do ambulatório de Neurologia com critérios clínicos para STC foram submetidos a uma bateria de testes clínicos e neurofisiológicos. Primeiramente, nós aplicamos o Questionário de Síndrome do túnel do Carpo de Boston e Escala visual analógica (EVA). Após, realizamos o método eletrofisiológico convencional de avaliação sensitiva do nervo mediano e ulnar. Posteriormente, outro médico eletrofisiologista, cegado para as avaliações anteriores, realizou a técnica de estimulação simultânea dos nervos mediano e radial no polegar com registro simultâneo de ambos potenciais na região punho. Os dados foram agrupados em STC leve, moderada e grave, baseados na latência motora do nervo mediano. Resultados A latência entre picos (LEP), obtida pela técnica em estudo, foi diferente entre os grupos baseados na classificação de gravidade da STC (Bonferroni; p<0.001). A velocidade de condução nervosa sensitiva do nervo mediano, obtida através da técnica standard, apresentou também diferentes valores entre os grupos. Houve correlação entre LEP e velocidade de condução nervosa sensitiva do mediano (Sperman; r=-0.52; p<0.01), bem como entre LEP e velocidade de condução nervosa sensitiva do mediano com o desconforto causado pela STC mensurado pela Escala visual analógica (EVA). A duração e o desconforto causado pela técnica de estimulação simultânea do nervo mediano e radial estão reduzidos quando comparados com a técnica padrão (t Student; p< 0.001 para as duas comparações). Conclusão A técnica de estimulação simultânea do nervo mediano e radial é acurada, sensível, tolerável e não somente útil no diagnóstico da STC, mas também na definição da gravidade. Então, seu uso deve ser encorajado na prática clínica. / Background Carpal tunnel syndrome (CTS) is the most common nerve entrapment observed in clinical practice affecting the median nerve at the wrist level. There are many electrophysiological ways to diagnose CTS, but most of them are time consuming, painful and have variable sensitivity. Objective To evaluate the accuracy of an electophysiologic method of CTS investigation and to correlate it with clinical symptoms. Methods Patients at the clinic outpatient Neurology with CTS clinical criteria underwent a battery of clinical and neurophysiological tests. First, we applied the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and Visual analogue scale (VAS). After, we performed a standard method of analysis of the median and ulnar nerves. Posteriorly, a blinded neurophysiologist performed an orthodromic median-radial nerve simultaneous stimulation at the thumb with recording of both action potentials at the lateral aspect of the wrist. Data were grouped for mild, moderate and severe CTS, based on median motor latency. Results The interpeak latency (IPL), obtained with study technique, was different in groups based on CTS classification severity (Bonferroni. p<0.001). The median nerve conduction velocity, obtained with the standard approach, was also of different level among groups. There were correlation between IPL and median nerve conduction velocity (Sperman; r=-0.52; p<0.01), as well as, there was a significant correlation between IPL and median nerve conduction velocity with the discomfort caused by CTS and measured with VAS. However, the duration and unpleasantness caused by median-radial nerve simultaneous stimulation technique were reduced when compared to standard approach (t Student <0.001 for both comparisons). Conclusion The orthodromic median-radial nerve simultaneous stimulation technique is accurate, sensitive, tolerable and not only useful for CTS diagnosis but also for its severity assessment. Therefore, its use should be encouraged in clinical practice.

Neurography is the most objective and reliable measure of the peripheral nerve function, and it is used to diagnose both local and generalized neuropathies. Neurography can measure both motor and sensory nerve functions. The principle for sensory neurgraphy is to stimulate over the nerve and record proximal or distal from the stimulated electrode. At the Department of Clinical Neurophysiology, University Hospital Uppsala, a problem has been identified, in that young adult patients tend to show unexpected abnormal neurography values in relation to the expected, indicated by the reference limits, without clinical correlates. This concerns foremost the sensory amplitudes in median and ulnar nerves. The hypothesis is that the requirement of young adults’ amplitudes is too high. A reference material better including more subjects in this age group may solve the problem. Sensory nerve conduction studies were performed in 33 subjects, aged 15-30. The nerve functions were tested on median, ulnar and radial nerves. Surface electrodes were used for both recording and stimulation. The result shows that the presently used reference material for some nerves indeed has too high requirement for young adults. After increasing the reference material for younger age groups, the new reference limits has been changed and this should cause fewer false positive findings.

Data from the McMaster Occupational Biomechanics Laboratory were consolidated to evaluate overall trends relating to tissue motion and blood flow in the carpal tunnel. Regarding tissue motion, displacements of the flexor digitorum superficialis (FDS) tendon and its subsynovial connective tissue (SSCT) were found to decrease with greater movement speed and a flexed wrist posture. Notably, changes to shear outcomes including relative tendon-SSCT displacement, the shear strain index (SSI), and maximum velocity ratio (MVR) demonstrate that greater movement speed contributes to SSCT damage according to the shear strain mechanism of injury theorised to promote carpal tunnel syndrome (CTS). Median nerve blood flow was also found to be implicated by wrist flexion, and appeared to decrease with greater CTS severity status. Finally, induced blood flow alteration of the carpal tunnel was found to elicit a median nerve blood flow response similar to the level found in CTS subjects, confirming its effectiveness as an intervention to study tissue motion in a CTS-like state. The influence of altered blood flow on tissue motion was differential, where the higher supradiastolic condition altered FDS displacement, and the lower subdiastolic condition affected SSCT displacement and SSI. These findings provide valuable evidence for changes in median nerve blood flow—and by extension, the local fluid environment within the carpal tunnel—not only being a consequence of SSCT fibrosis characteristic of CTS, but potentially also acting as a cause for said changes in carpal tunnel tissue motion. / Thesis / Master of Science in Kinesiology / This thesis aimed to evaluate and summarize key findings from the McMaster Occupational Biomechanics Laboratory relating to tissue motion and blood flow in the carpal tunnel. Performing repetitive finger movements faster and with a flexed wrist posture were found to decrease the distance travelled of the underlying finger tendon. Blood flow of the median nerve, which is implicated in carpal tunnel syndrome (CTS), is higher with forceful exertion and flexed wrist posture, and lower with greater severity of CTS. Finally, altering blood flow to the carpal tunnel was found to create a CTS-like environment, affected tissue motion in the carpal tunnel, and promoted movement disparity between these tissues that is associated with injury. This suggests that fluid/blood flow changes affecting the carpal tunnel is a plausible mechanism for increasing the likelihood of developing CTS.

Many epidemiological studies have named pinching, deviated wrist postures, and repetitive motion as ergonomic risk factors in the development of carpal tunnel syndrome (CTS). Evidence suggests that hypervascularization of the median nerve and increased intraneural blood flow proximal to the carpal tunnel result in response to ergonomic risk factors (finger pressing and deviated wrist postures). The purposes of this study were to 1) determine the effect of a pinch posture, with and without force exerted by the finger, thumb, or both and 2) determine the effect of repetitive wrist flexion and extension on intraneural blood flow velocity in the median nerve proximal to the carpal tunnel. Eleven healthy and eleven CTS symptomatic individuals participated in this study and completed three components: 15 pinch posture force trials, 3 repetitive wrist motion trials, and 3 static wrist posture trials. Intraneural blood flow was measured using pulse wave Doppler during each trial. Main effects of pinch posture force (F4,80 = 21.397, p < 0.001) and wrist posture (F2,40 = 14.545, p < 0.001) were observed. Trials where force was applied by the finger (2.21 cm/s), thumb (2.22 cm/s) or both (2.34 cm/s) produced higher intraneural blood flow velocities than trials with no force (1.79 cm/s) or relaxed hand (1.89 cm/s). Trials performed in flexion (2.24 cm/s) were greater than neutral (2.06 cm/s) and extension (1.97 cm/s). No interactions or main effects of time were found in response to repetitive wrist motion. These results suggest that at low force levels (6 N) it’s not how the force is applied but rather that the force is being applied that has an effect on the median nerve. Additionally these results suggest that the contribution of repetitive motion to the development of CTS may not be directly to the median nerve. / Thesis / Master of Science (MSc)

INTRODUÇÃO: A recuperação de sensibilidade protetora na mão deve fazer parte da estratégia na reconstrução cirúrgica das lesões completas do plexo braquial. Existem poucos nervos doadores de fibras sensitivas disponíveis e há poucos trabalhos relacionados na literatura. Um possível doador é o nervo intercostobraquial (NICB), que é o ramo cutâneo lateral do segundo nervo intercostal que inerva a pele da região póstero-medial do braço e da axila. OBJETIVOS: Avaliar a viabilidade anatômica de utilização do NICB como doador de fibras sensitivas para a contribuição do cordão lateral para o nervo mediano (CLNM) e comparar o número de fibras do NICB e da CLNM, para analisar a compatibilidade anatômica entre esses nervos. MÉTODOS: Trinta cadáveres adultos não fixados foram dissecados no Serviço de Verificação de Óbitos da Capital da Universidade de São Paulo, São Paulo, Brasil. Dados de sexo, altura e peso foram registrados. O NICB e o plexo braquial infraclavicular à direita foram expostos e parâmetros anatômicos como número de ramos na origem, diâmetro e divisões no curso do NICB foram mensurados, caracterizados e registrados, assim como o diâmetro da CLNM. As distâncias entre a origem do NICB e seu ponto de divisão e ponto de coaptação com a CLNM também foram medidas e registradas. Fragmentos de nervos foram retirados dos últimos dez espécimes para análise histomorfométrica com contagem do número de fibras de quatro nervos: NICB, nervo supraclavicular (NSC), terceiro nervo intercostal (3ºNIC) e CLNM. RESULTADOS: Oito cadáveres eram do sexo feminino e 22 do masculino. A média de idade, altura e peso foram, respectivamente, 62 anos, 166 cm e 59,5 Kg. O diâmetro médio do NICB na sua origem foi de 2,1 mm e no seu ponto de coaptação de 2,7 mm. O diâmetro médio da CLNM foi de 3,7 mm. Vinte e oito (93,3%) NICBs apresentaram-se como tronco único em sua origem e, em seu trajeto na axila, 22 deles (73,3%) se dividiram em 2 ramos, sete (23,3%) dividiram-se em três ramos e um atingiu o braço como tronco único. As distâncias médias entre a origem do NICB e o seu ponto de ramificação e de coaptação à CLNM foram 23,8 mm e 54 mm, respectivamente. Todos os NICBs dissecados tinham extensão suficiente para alcançar a CLNM. Os números médios de fibras do NICB, NSC, 3ºNIC e CLNM foram 984, 693, 470 e 5273, respectivamente. A análise estatística mostrou diferença significativa entre o NICB e o 3ºNIC, e entre a CLNM (receptor) e os outros potenciais nervos doadores (NICB, NSC e 3ºNIC). CONCLUSÕES: A transferência do NICB como um doador de axônios sensitivos para a CLNM foi anatomicamente viável. O NICB apresenta número de fibras maior do que o 3ºNIC, mas sem diferença significativa em comparação com o NSC. Considerando a importância da recuperação da sensibilidade protetora na mão, esta técnica pode se tornar importante contribuição em doentes com lesões completas do plexo braquial / INTRODUCTION: Restoration of protective sensory function in the hand should be mandatory in the surgical reconstruction of complete brachial plexus lesions. There are few available donors and related papers in the literature are scanty. One possible donor is the intercostobrachial nerve (ICBN), which is the lateral cutaneous branch of the second intercostal nerve that supplies the skin of the medial and posterior parts of the arm and the skin of the axilla. OBJECTIVES: To evaluate the anatomical viability of using the ICBN as a donor of sensitive axons to the lateral cord contribution to the median nerve (LCMN) and to compare the number of fibers of the ICBN, and the LCMN, to analyze the anatomical compatibility between these nerves. METHODS: Thirty non-fixed adult cadavers were dissected at the Serviço de Verificação de Óbitos da Capital of University of São Paulo, São Paulo, Brazil. Data of sex, height and weight were registered. The right ICBN and infraclavicular brachial plexus were exposed and measurements of diameters of the ICBN and of the LCMN were performed. Number of branches at ICBN origin and number of divisions were registered. Distances between the origin of the ICBN and its point of division and point of coaptation to the LCMN were also measured. Histomorphometric analysis of the last ten specimens was performed with fibers counting of four distal nerves: ICBN, supraclavicular nerve (SCN), third intercostal nerve (3rdICN) and LCMN. RESULTS: Eight cadavers were female and 22 male. The mean age, height and weight were, respectively, 62 yo, 166 cm and 59,5 Kg. The mean diameter of the ICBN at its origin was 2,1 mm and at its point of coaptation was 2,7 mm, and the mean diameter of the LCMN was 3,7 mm. Twenty eight (93,3%) ICBNs had only one branch at their origin and, in their axillary course, 22 of them (73,3%) divided in 2 branches, seven (23,3%) divided in 3 branches and one reached the arm as a single nerve. The divisions of the ICBN occurred in a mean distance of 23,8 mm from their origin. The mean distance between the origin of the ICBN and its point of coaptation to the LCMN was 54 mm. All the ICBNs dissected had enough extension to reach the LCMN. The mean numbers of fibers of the ICBN, SCN, 3rdICN and LCMN were 984, 693, 470 and 5273, respectively. Statistical analysis demonstrated significant difference between the ICBN and the 3rdICN, and between the LCMN (recipient) and the other potential donor nerves (ICBN, SCN and 3rdICN). CONCLUSIONS: This study demonstrated the anatomical feasibility of the transfer of the ICBN as a donor of sensitive axons to the LCMN. The ICBN has a number of fibers greater than that of the ICN, but without significant difference in comparison to the SCN. Considering the importance of the recovery of protective sensibility in the hand, this technique may become an important contribution in the treatment of patients with complete lesions of the brachial plexus

Background - Hand intense occupational activities have been associated with an increase in the incidence of carpal tunnel syndrome (CTS). CTS is characterized by an impairment of median nerve function. To date, a dose-response relationship between wrist activity and median nerve performance has not been documented. Since repetitive hand/wrist activity in the workplace has significant implications, it is important to establish a scientific basis for the aetiology of work-related carpal tunnel syndrome. Methods -- In a laboratory environment, twenty-seven clinically confirmed asymptomatic female subjects performed continuous repetitive wrist motion in the flexion-extension plane during which an angle of 120 degrees was subtended about the neutral wrist position. Four levels of wrist activity, corresponding with 0 (static), 22 (Iow), 38 (medium) and 49 (high) repetitions per minute, were prescribed. Wrist motion was recorded using a state-of-the-art 3D electromagnetic tracking system (HumanTRAC). Mathematical descriptors of wrist kinematics, including cycle time, amplitude, angular velocity and angular acceleration, were calculated. Sensory median nerve response to imposed physical stressors was monitored antidromically and recorded using a clinical electroneurometer every ten minutes throughout the simulated work activities. Near-nerve skin temperature was recorded at three sites along the distal sensory branch of the median nerve every twenty minutes. Results - After adjusting for changes in near-nerve skin temperature, a significant within-subject effect of duration of exposure (time) was detected. Sensory median nerve conduction velocity differed statistically by 2.1 ms-1 between the static and high wrist activity conditions after 120 minutes of exposure, signifying adverse effects on nerve conduction that are uniquely attributable to repetitive hand motion. Wrist activity measures of mean angular acceleration presented a highly significant association with nerve performance, where nerve conduction decreased as wrist activity increased. Using regression analysis, a maximum safe wrist-workload exposure limit of 0.91 repetitions per minute is proposed. Limitations of this result are discussed. A biomechanical model is presented to calculate the effect of physical risk factors on tendon forces at the wrist. This model offers a method by which findings of the study can be employed for workplace exposure surveillance and development of ergonomic workstation design recommendations. Conclusions -- Across the study population of clinically asymptomatic female participants, a change in median nerve performance was observed. This significant effect was evoked due to imposed physical stressors. A dose response relationship between work intensity, exposure time and median nerve conduction velocity was demonstrated. The research explored in this thesis presents a foundation for the future development of a "Dynamic Median Nerve Stress Test". This test would involve the performance of a repetitive motion activity of the wrist during which changes in the function of the median nerve are closely monitored. The Dynamic Median Nerve Stress Test might prove to be valuable both as a provocative clinical test as well as an important research tool.

Στην μελέτη μας - που σκοπό είχε την αναζήτηση των ηλεκτροφυσιολογιών παραμέτρων εκείνων οι οποίες πρωϊμώτερα καθίστανται παθολογικές σε αρχόμενη συμπιεστική βλάβη του μέσου νεύρου στον καρπό - εξετάσαμε συνολικά 72 ασθενείς (42 χέρια δεξιά, 30 αριστερά) από τους οποίους οι 66 ήταν γυναίκες και οι 6 άνδρες. Ο μέσος όρος ηλικίας των ασθενών ήταν 49.6±9.8 έτη. Όρος επιλογής των προς μελέτη ασθενών ήταν να παρουσιάζουν συμπτώματα και σημεία τέτοια ώστε κλινικά να τίθεται βάσιμα η υπόνοια συνδρομής καρπιαίου σωλήνα, ταυτόχρονα όμως, στον ηλεκτρονευρογραφικό έλεγχο η τιμή του τελικού κινητικού χρόνου να μην υπερβαίνει τα 4.2 msec, ώστε να εξασφαλίζεται το αρχόμενο - μη προχωρημένο της συμπιεστικής συνδρομής. Στην μελέτη χρησιμοποιήθηκαν και 43 μάρτυρες (19 χέρια δεξιά, 24 χέρια αριστερά). Οι μάρτυρες επελέγησαν με κριτήρια την παντελή απουσία συμπτωμάτων και σημείων από το περιφερικό νευρικό σύστημα και με τον περιορισμό της ουδέποτε λήψης νευροτοξικών ουσιών. Από αυτούς οι 31 ήταν γυναίκες και οι 12 άνδρες, είχαν δε μέσο όρο ηλικίας 41.3±16.4 έτη. Τόσο στους ασθενείς όσο και στους μάρτυρες μελετήθηκαν οι αισθητικές αγωγιμότητες με την ορθοδρομική μέθοδο. Σε κάθε χέρι η μελέτη έγινε με ερεθισμό ένα προς ένα όλων των δακτύλων (1ου, 2ου, 3ου και 4ου) και καταγραφή με επιφανειακό ηλεκτρόδιο στον καρπό από το μέσο νεύρο επιπλέον ερεθίστηκε και ο 5ος δάκτυλος και κατεγράφη το αισθητικό δυναμικό στον καρπό από το ωλένιο νεύρο. Τα αποτελέσματα αυτών των καταγραφών αφορούσαν όλες τις παραμέτρους του αισθητικού δυναμικού (λανθάνων χρόνος, εύρος, διάρκεια) καθώς και αλλοιώσεις της μορφολογίας του, από όλους τους δακτύλους. Στη συνέχεια προχωρήσαμε σε πολλαπλές συσχετίσεις κάθε μιας παραμέτρου σε διαφορετικούς δακτύλους, διαφορετικών παραμέτρων στον ίδιο δάκτυλο, αλλά και σε διαφορετικούς δακτύλους καθώς και στην απαρίθμηση των ανώμαλων κυματομορφών όπου αυτές εμφανίζονταν. Η στατιστική επεξεργασία όλων αυτών των δεδομένων κατέληξε στην συγκρότηση μιας κλίμακος ευαισθησίας ως προς την εγκαιρότερη αλλοίωση ηλεκτροφυσιολογιών παραμέτρων σε αρχόμενη συνδρομή καρπιαίου σωλήνα. Συμπερασματικά από τη μελέτη μας προκύπτουν τα εξής: 1) Η ανάδειξη δικόρυφου δυναμικού ενεργείας σε ερεθισμό είτε του 4ου είτε του 1ου δακτύλου είναι συχνό και ισχυρό εύρημα ως προς την τεκμηρίωση αρχόμενης συνδρομής καρπιαίου σωλήνα. 2) Σε αρχόμενη συνδρομή καρπιαίου σωλήνα πρώιμα παρατείνεται ο λανθάνων χρόνος από 4ο και από 1ο δάκτυλο, αλλοιώνονται όλες οι παράμετροι από τον 4ο δάκτυλο και παρατείνεται ο λανθάνων χρόνος από 3ο δάκτυλο. Δεν υπήρξε διαφοροποίηση των παραπάνω αποτελεσμάτων που να συσχετίζονται με το φύλο ή την ηλικία. / The purpose of the present work was to investigate cases with early median nerve entrapment neuropathy (carpal tunnel syndrome) and to identify the most sensitive neurophysiological parameter by which an early diagnosis of the syndrome can be established. We examined 72 patients (42 right hands and 30 left hands) 66 women and 6 men. The mean age was 49.6±9.8 years. The inclusion criteria were symptoms and signs compatible with the diagnosis of carpal tunnel syndrome and the distal motor latency to be less than 4.2msec. We also examined 43 control subjects (19 right hands and 24 left hands) 31 women and 12 men with a mean age 41.3±16.4 years The control subjects were free of peripheral neurological problems. In all patients and control subjects we studied the sensory conduction parameters using the orthodrom method. In all hands we stimulated all five fingers and we recorded the sensory potentials from the wrist for both nerves (the median nerve for the 4 first fingers and the ulnar nerve for the 5th finger). In all patients and controls median distal motor latency, amplitude and duration of compound sensory nerve action potentials and sensory nerve conduction velocity of all five fingers were measured. The statistical analysis of the results showed the following conclusions. 1. Double peak potentials after stimulation of the 4th finger was the most sensitive test for detecting early carpal tunnel syndrome. Double peak potentials after stimulation of the 1st finger was a less frequent finding. 2. In early carpal tunnel syndrome there is a prolongation of the latency of the 4th and 1st finger Also there are changes in all parameters of the 4th finger potential and there is a prolongation of the latency of 3rd finger. Finally there were no differences between male and female measurements.

INTRODUÇÃO: A recuperação de sensibilidade protetora na mão deve fazer parte da estratégia na reconstrução cirúrgica das lesões completas do plexo braquial. Existem poucos nervos doadores de fibras sensitivas disponíveis e há poucos trabalhos relacionados na literatura. Um possível doador é o nervo intercostobraquial (NICB), que é o ramo cutâneo lateral do segundo nervo intercostal que inerva a pele da região póstero-medial do braço e da axila. OBJETIVOS: Avaliar a viabilidade anatômica de utilização do NICB como doador de fibras sensitivas para a contribuição do cordão lateral para o nervo mediano (CLNM) e comparar o número de fibras do NICB e da CLNM, para analisar a compatibilidade anatômica entre esses nervos. MÉTODOS: Trinta cadáveres adultos não fixados foram dissecados no Serviço de Verificação de Óbitos da Capital da Universidade de São Paulo, São Paulo, Brasil. Dados de sexo, altura e peso foram registrados. O NICB e o plexo braquial infraclavicular à direita foram expostos e parâmetros anatômicos como número de ramos na origem, diâmetro e divisões no curso do NICB foram mensurados, caracterizados e registrados, assim como o diâmetro da CLNM. As distâncias entre a origem do NICB e seu ponto de divisão e ponto de coaptação com a CLNM também foram medidas e registradas. Fragmentos de nervos foram retirados dos últimos dez espécimes para análise histomorfométrica com contagem do número de fibras de quatro nervos: NICB, nervo supraclavicular (NSC), terceiro nervo intercostal (3ºNIC) e CLNM. RESULTADOS: Oito cadáveres eram do sexo feminino e 22 do masculino. A média de idade, altura e peso foram, respectivamente, 62 anos, 166 cm e 59,5 Kg. O diâmetro médio do NICB na sua origem foi de 2,1 mm e no seu ponto de coaptação de 2,7 mm. O diâmetro médio da CLNM foi de 3,7 mm. Vinte e oito (93,3%) NICBs apresentaram-se como tronco único em sua origem e, em seu trajeto na axila, 22 deles (73,3%) se dividiram em 2 ramos, sete (23,3%) dividiram-se em três ramos e um atingiu o braço como tronco único. As distâncias médias entre a origem do NICB e o seu ponto de ramificação e de coaptação à CLNM foram 23,8 mm e 54 mm, respectivamente. Todos os NICBs dissecados tinham extensão suficiente para alcançar a CLNM. Os números médios de fibras do NICB, NSC, 3ºNIC e CLNM foram 984, 693, 470 e 5273, respectivamente. A análise estatística mostrou diferença significativa entre o NICB e o 3ºNIC, e entre a CLNM (receptor) e os outros potenciais nervos doadores (NICB, NSC e 3ºNIC). CONCLUSÕES: A transferência do NICB como um doador de axônios sensitivos para a CLNM foi anatomicamente viável. O NICB apresenta número de fibras maior do que o 3ºNIC, mas sem diferença significativa em comparação com o NSC. Considerando a importância da recuperação da sensibilidade protetora na mão, esta técnica pode se tornar importante contribuição em doentes com lesões completas do plexo braquial / INTRODUCTION: Restoration of protective sensory function in the hand should be mandatory in the surgical reconstruction of complete brachial plexus lesions. There are few available donors and related papers in the literature are scanty. One possible donor is the intercostobrachial nerve (ICBN), which is the lateral cutaneous branch of the second intercostal nerve that supplies the skin of the medial and posterior parts of the arm and the skin of the axilla. OBJECTIVES: To evaluate the anatomical viability of using the ICBN as a donor of sensitive axons to the lateral cord contribution to the median nerve (LCMN) and to compare the number of fibers of the ICBN, and the LCMN, to analyze the anatomical compatibility between these nerves. METHODS: Thirty non-fixed adult cadavers were dissected at the Serviço de Verificação de Óbitos da Capital of University of São Paulo, São Paulo, Brazil. Data of sex, height and weight were registered. The right ICBN and infraclavicular brachial plexus were exposed and measurements of diameters of the ICBN and of the LCMN were performed. Number of branches at ICBN origin and number of divisions were registered. Distances between the origin of the ICBN and its point of division and point of coaptation to the LCMN were also measured. Histomorphometric analysis of the last ten specimens was performed with fibers counting of four distal nerves: ICBN, supraclavicular nerve (SCN), third intercostal nerve (3rdICN) and LCMN. RESULTS: Eight cadavers were female and 22 male. The mean age, height and weight were, respectively, 62 yo, 166 cm and 59,5 Kg. The mean diameter of the ICBN at its origin was 2,1 mm and at its point of coaptation was 2,7 mm, and the mean diameter of the LCMN was 3,7 mm. Twenty eight (93,3%) ICBNs had only one branch at their origin and, in their axillary course, 22 of them (73,3%) divided in 2 branches, seven (23,3%) divided in 3 branches and one reached the arm as a single nerve. The divisions of the ICBN occurred in a mean distance of 23,8 mm from their origin. The mean distance between the origin of the ICBN and its point of coaptation to the LCMN was 54 mm. All the ICBNs dissected had enough extension to reach the LCMN. The mean numbers of fibers of the ICBN, SCN, 3rdICN and LCMN were 984, 693, 470 and 5273, respectively. Statistical analysis demonstrated significant difference between the ICBN and the 3rdICN, and between the LCMN (recipient) and the other potential donor nerves (ICBN, SCN and 3rdICN). CONCLUSIONS: This study demonstrated the anatomical feasibility of the transfer of the ICBN as a donor of sensitive axons to the LCMN. The ICBN has a number of fibers greater than that of the ICN, but without significant difference in comparison to the SCN. Considering the importance of the recovery of protective sensibility in the hand, this technique may become an important contribution in the treatment of patients with complete lesions of the brachial plexus