RESUMO
BACKGROUND: Giant cell tumor of the tendon sheath is the most common form of giant cell tumors and is the second most common soft tissue tumor of the hand region after ganglion cyst. Magnetic resonance imaging is the diagnostic tool of choice for both diagnosis and treatment planning. The current standard treatment of choice is simple excision. The main concern about the treatment is related to the high recurrence rates. Besides incomplete excision, there is no consensus concerning the effect of other risk factors on recurrence. The literature lacks detailed reports on surgical excision of these tumors with a standardized surgical treatment and an appropriate patient follow up. The aim of this study was to investigate the recurrence rate and the associated recurrence risk factors for giant cell tumor of tendon sheath of the hand following a standardized treatment. METHODS: The records of patients treated for giant cell tumor of tendon sheath of the hand treated by the same hand surgeon were evaluated retrospectively. The features obtained from preoperative magnetic resonance imaging, final physical examination, patients' age and sex, anatomical site of the tumor, relationship of the tumor with bone, joint or neurovascular structures, bone invasion, recurrence after surgery and complications like skin necrosis, digital neuropathy or limitation in range of motion were documented. Chi-square test was used to compare categorical variables. RESULTS: Fifty patient were included in the study. The average follow-up time was 84 months. Three recurrences (6%) were recorded. The only significant risk factor for the recurrence was tumor adjacency to the interphalangeal joints of the fingers other than thumb. No major or minor complications were encountered in the postoperative period. CONCLUSION: With adequate surgical exposure and meticulous dissection provided by the magnification loupes, we were able demonstrate one of the lowest recurrence rates in the literature. Well-designed studies combining the recurrence rates of several hand surgery centers implementing a standardized treatment are needed to better demonstrate the associated risk factors for recurrence.
Assuntos
Tumor de Células Gigantes de Bainha Tendinosa/diagnóstico , Tumor de Células Gigantes de Bainha Tendinosa/cirurgia , Mãos/cirurgia , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/cirurgia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Mãos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Adulto JovemRESUMO
PURPOSE: Magnetic resonance (MRI) is a valuable imaging method which can detect pre-operative rotator cuff tear characteristics accurately. However, tendon degeneration almost always necessitates a certain amount of debridement during arthroscopic repair, which alters tear size and shape. The aim of this study is to question the accuracy of the pre-operative tear size and classification in MRI and its relation to the tear size and type of the debrided tendon during arthroscopic repair. METHODS: A retrospective survey was performed to identify shoulders that underwent arthroscopic rotator cuff repair. Rotator cuff tears with an adequate history, a standard pre-operative MRI, and available surgical video records with appropriate measurements were included. Traumatic tears, calcifying tendonitis, isolated subscapularis tears, and revisions were excluded. In total, 60 shoulders' (30 males, 27 females; age 55.2 [35-73]) preoperative MRIs and intra-operative measurements were analyzed by orthopaedic surgeons and radiologists. Tear width and type were recorded. Interdisciplinary and intradisciplinary consistency of measurements and classifications were analyzed. Tear width measured on pre-operative MRI and after debridement were compared. RESULTS: Average measured tear width was 9 ± 5.3 mm on MRI. Surgeons (9.98 ± 4.6 mm) measured tears significantly wider than radiologists (7.71 ± 6.6 mm). Radiologists (ICC, 0.930; CI, 0.883-0.959) showed superior consistency on MRI than surgeons (CI, 0.502; CI, 0.105-0.726). Average tear width measured after debridement (29.3 ± 9.6 mm) was significantly higher than tear width measured on pre-operative MRI (p < 0.0001). None of the researchers assessing tear type on pre-operative MRI showed agreement with surgeons assessing intra-operative data. CONCLUSIONS: There were significant differences between the pre-operative tear characteristics on MRI and the debrided tendon characteristics during surgery, which were extensive enough to classify the tear in a different category.
Assuntos
Imageamento por Ressonância Magnética , Lesões do Manguito Rotador/diagnóstico por imagem , Lesões do Manguito Rotador/cirurgia , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/cirurgia , Adulto , Idoso , Artroscopia , Desbridamento , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Estudos RetrospectivosRESUMO
STUDY DESIGN: Case report. INTRODUCTION: Development of extensor tendon adhesions is a common complication after intra-articular metacarpal head fracture. Whenever these adhesions cannot be mobilized by rehabilitation, tenolysis should be considered. However, the decision for tenolysis is often delayed. When the rehabilitation program comes to a plateau and clinical examination may not be sufficient to find out the cause, dynamic ultrasound (US) can show where the gliding mechanism is disrupted and help clinicians to give an accurate decision for determining the next steps. PURPOSE OF THE STUDY: To determine the role of dynamic US during hand rehabilitation. METHODS: A 22-year-old woman presented with a fifth metacarpal intra-articular head fracture. Ten days after the surgery (open reduction and internal fixation) the hand rehabilitation program was commenced. After the third week, the metacarpophalangeal (MP) joint range of motion (ROM) gradually diminished. Dynamic US near the level of fifth MP joint revealed diminished extensor tendon excursion and capsular thickening. RESULTS: Considering physical and sonographic findings, surgical tenolysis and capsular release was planned. After surgery, the DIP, PIP and MP joints reached full passive ROM. CONCLUSION(S): Ultrasound is a quick and practical way to diagnose tendon adhesions. With this report, the authors suggest that clinicians may use dynamic US, especially in times when the patient comes to plateau during hand rehabilitation. LEVEL OF EVIDENCE: IV.
Assuntos
Fraturas Intra-Articulares/cirurgia , Ossos Metacarpais/cirurgia , Complicações Pós-Operatórias , Tendões/diagnóstico por imagem , Aderências Teciduais/diagnóstico por imagem , Feminino , Fixação Interna de Fraturas , Humanos , Articulação Metacarpofalângica/fisiopatologia , Redução Aberta , Amplitude de Movimento Articular/fisiologia , Adulto JovemRESUMO
PURPOSE: Latarjet, which is a coracoid bone block procedure, is an effective treatment for anterior shoulder instability with glenoid bone loss. During this reconstructive procedure the subscapularis may be tenotomized or be split to expose the glenoid neck. The aim of this study was to assess the effect of subscapularis management on functional outcomes and internal and external rotation durability and strength. Hypothesis is that the subscapularis split approach will result in better functional results and superior internal rotation strength and endurance. METHODS: The study included 48 patients [median age 30 (range 16-69); 42 males, 6 females], who underwent a modified Latarjet procedure for anterior shoulder instability. There were 20 patients in the subscapularis tenotomy group and 28 patients in the subscapularis split group. The groups were compared isokinetically using a computerized dynamometer for internal and external rotation durability and strength. At the latest follow-up, the patients were evaluated with the American Shoulder and Elbow Surgeons (ASES) and ROWE scores for functional outcomes. RESULTS: At a median follow-up period of 25 (range 12-73) months after the Latarjet procedure, the internal rotation durability was significantly higher in the split group (p = 0.045). However, a statistically significant difference could not be found for internal and external rotational strengths (n.s.). There was also no significant difference between the final ASES and ROWE scores (n.s.). CONCLUSION: Although both approaches offer promising results, the subscapularis split approach appears to provide better internal rotation durability compared to subscapularis tenotomy. Therefore, the subscapularis split approach may be more preferable for the management of the subscapularis muscle during Latarjet procedure. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.
Assuntos
Processo Coracoide/cirurgia , Instabilidade Articular/cirurgia , Manguito Rotador/cirurgia , Luxação do Ombro/cirurgia , Articulação do Ombro/cirurgia , Adolescente , Adulto , Idoso , Transplante Ósseo , Dissecação , Feminino , Humanos , Instabilidade Articular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Dinamômetro de Força Muscular , Amplitude de Movimento Articular , Procedimentos de Cirurgia Plástica/métodos , Recuperação de Função Fisiológica , Estudos Retrospectivos , Rotação , Ombro/fisiopatologia , Ombro/cirurgia , Luxação do Ombro/fisiopatologia , Articulação do Ombro/fisiopatologia , Tenotomia , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Transfer of the latissimus dorsi tendon to the posterosuperior part of the rotator cuff is an option in active patients with massive rotator cuff tears to restore shoulder elevation and external rotation. However, it is unknown whether this treatment prevents progression of cuff tear arthropathy. QUESTIONS/PURPOSES: The purpose of this study was to determine whether the observed improvement in shoulder function in the early postoperative period with latissimus dorsi tendon transfer for irreparable rotator cuff tears will be permanent or will deteriorate in the midterm period (at 1-5 years after surgery). METHODS: During a 6-year period, we performed 11 latissimus dorsi tendon transfers in 11 patients for patients with massive, irreparable, chronic tears of the posterosuperior part of the rotator cuff (defined as > 5 cm supraspinatus and infraspinatus tendon tears with Goutallier Grade 3 to 4 fatty infiltration on MRI), for patients who were younger than 65 years of age, and had high functional demands and intact subscapularis function. No patients were lost to followup; minimum followup was 12 months (median, 33 months; range, 12-62 months). The mean patient age was 55 years (median, 53 years; range, 47-65 years). Shoulder forward elevation, external rotation, and Constant-Murley and American Shoulder and Elbow Surgeons scores were assessed. Pain was assessed by a 0- to 10-point visual analog scale. Acromiohumeral distance and cuff tear arthropathy (staged according to the Hamada classification) were evaluated on radiographs. RESULTS: Shoulder forward elevation, external rotation, Constant-Murley scores, and American Shoulder and Elbow Surgeons scores improved at 6 months. However, although shoulder motion values and Constant-Murley scores remained unchanged between the 6-month and latest evaluations, American Shoulder and Elbow Surgeons scores decreased in this period (median, 71; range, 33-88 versus median, 68; range, 33-85; p = 0.009). Visual analog scale scores improved between the preoperative and 6-month evaluations but then worsened (representing worse pain) between the 6-month and latest evaluations (median, 2; range, 0-5 versus median, 2; range, 1-6; p = 0.034), but scores at latest followup were still lower than preoperative values (median, 7; range, 4-8; p = 0.003). Although acromiohumeral distance values were increased at 6 months (median, 8 mm; range, 6-10 mm; p = 0.023), the values at latest followup (median, 8 mm; range, 5-10 mm) were no different from the preoperative ones (mean, 7 mm; range, 6-9 mm; p > 0.05). According to Hamada classification, all patients were Grade 1 both pre- and postoperatively, except one who was Grade 3 at latest followup. CONCLUSIONS: The latissimus dorsi tendon transfer may improve shoulder function in irreparable massive rotator cuff tears. However, because the tenodesis effect loses its strength with time, progression of the arthropathy should be expected over time. Nevertheless, latissimus dorsi tendon transfer may help to delay the need for reverse shoulder arthroplasty for these patients. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
Assuntos
Manguito Rotador/cirurgia , Articulação do Ombro/cirurgia , Músculos Superficiais do Dorso/cirurgia , Traumatismos dos Tendões/cirurgia , Transferência Tendinosa/métodos , Tenodese/métodos , Idoso , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Radiografia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/fisiopatologia , Lesões do Manguito Rotador , Lesões do Ombro , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/fisiopatologia , Dor de Ombro/etiologia , Músculos Superficiais do Dorso/diagnóstico por imagem , Músculos Superficiais do Dorso/fisiopatologia , Traumatismos dos Tendões/diagnóstico , Traumatismos dos Tendões/fisiopatologia , Transferência Tendinosa/efeitos adversos , Tenodese/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVE: This study aimed to investigate the effects of the accompanying ulnar styloid fracture and 2 different postoperative rehabilitation protocols on the final outcomes following surgical treatment of distal radius fractures. METHODS: In this retrospective study, 47 patients (11 male, 35 female; mean age=52.6 years, age range=24-85) who underwent plate fixation for distal radius fractures were divided into 4 groups based on the presence of an ulnar styloid fracture and type of rehabilitation. To evaluate clinical outcomes, wrist range of motion (ROM), grip strength, lateral pinch strength, disabilities of the arm, shoulder, and hand (DASH) questionnaire scores and visual analog scale (VAS) scores were obtained at the final follow-up. The rehabilitation exercises of the patients in groups 1 and 2 were carried out in the physical therapy room by the hand therapist during the postoperative 2 months. Patients in groups 3 and 4 were supplied with videos of the exercises of each phase and instructed to carry out those exercises at home routinely. RESULTS: Patients who received home rehabilitation programs demonstrated greater grip strength loss. Patients without accompanying ulnar styloid fractures had better DASH and VAS scores. Final wrist ROM and the duration for return to preinjury activity level did not differ among groups. CONCLUSION: This study has suggested that accompanying ulnar styloid fractures may worsen the functional outcomes after plate fixation of distal radius fractures. Home-based programs may provide patients with adequate overall wrist function with certain drawbacks compared to rehabilitation under direct supervision.
Assuntos
Fraturas do Rádio , Fraturas da Ulna , Fraturas do Punho , Traumatismos do Punho , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Fixação Interna de Fraturas/métodos , Articulação do Punho/cirurgia , Traumatismos do Punho/cirurgia , Amplitude de Movimento Articular , Fraturas do Rádio/cirurgia , Placas Ósseas , Resultado do TratamentoRESUMO
BACKGROUND: Patients with obstetrical brachial plexus palsy (OBPP) sequela exhibit adduction and internal rotation contractures. The muscular imbalance may result in secondary bony changes. Tendon transfers and muscular releases may improve shoulder function in these patients. The aim of this study is to evaluate the functional and radiological results of pectoralis major tendon Z-plasty with transfer of latissimus dorsi and teres major tendons to rotator cuff tendons without release of subscapularis muscle in patients with mild sequela of OBPP. MATERIALS AND METHODS: Twenty-six consecutive patients, who were treated with tendon transfer and met the eligibility criteria, were included in the study. No additional humeral osteotomy or subscapularis tenotomy was performed. Functional evaluation is made according to range of motion and Mallet scoring system. Preoperative radiologic evaluation was made according to the grading system of Waters. RESULTS: A significant increase in shoulder function was found in all patients. Postoperative radiographs revealed glenohumeral congruity was maintained in all patients. Improvement in shoulder abduction and external rotation was higher in patients who were operated before the age of 7. DISCUSSION/CONCLUSION: Pectoralis major tendon lengthening with transfer of latissimus dorsi and teres major tendons to rotator cuff is an effective and reproducible technique and can improve shoulder functions in patients with OBPP. Subscapularis release is not always required to overcome internal rotation contracture. Secondary glenohumeral changes might also be prevented with this approach.
Assuntos
Traumatismos do Nascimento/complicações , Neuropatias do Plexo Braquial/cirurgia , Plexo Braquial/cirurgia , Músculo Esquelético/cirurgia , Osteotomia/métodos , Transferência Tendinosa/métodos , Adolescente , Traumatismos do Nascimento/fisiopatologia , Traumatismos do Nascimento/cirurgia , Plexo Braquial/lesões , Plexo Braquial/fisiopatologia , Neuropatias do Plexo Braquial/etiologia , Neuropatias do Plexo Braquial/fisiopatologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Músculo Esquelético/fisiopatologia , Músculos Peitorais/fisiopatologia , Músculos Peitorais/cirurgia , Amplitude de Movimento Articular , Articulação do Ombro/fisiopatologia , Articulação do Ombro/cirurgia , Fatores de Tempo , Resultado do TratamentoRESUMO
Elevated Reactive Oxygen Species (ROS) generated by the conventional cancer therapies and the endogenous production of ROS have been observed in various types of cancers. In contrast to the harmful effects of oxidative stress in different pathologies other than cancer, ROS can speed anti-tumorigenic signaling and cause apoptosis of tumor cells via oxidative stress as demonstrated in several studies. The primary actions of antioxidants in cells are to provide a redox balance between reduction-oxidation reactions. Antioxidants in tumor cells can scavenge excess ROS, causing resistance to ROS induced apoptosis. Various chemotherapeutic drugs, in their clinical use, have evoked drug resistance and serious side effects. Consequently, drugs having single-targets are not able to provide an effective cancer therapy. Recently, developed hybrid anticancer drugs promise great therapeutic advantages due to their capacity to overcome the limitations encountered with conventional chemotherapeutic agents. Hybrid compounds have advantages in comparison to the single cancer drugs which have usually low solubility, adverse side effects, and drug resistance. This review addresses two important treatments strategies in cancer therapy: oxidative stress induced apoptosis and hybrid anticancer drugs.
Assuntos
Neoplasias , Estresse Oxidativo , Antioxidantes , Apoptose , Humanos , Oxirredução , Espécies Reativas de OxigênioRESUMO
Osteosarcoma (OS) is the second most common primary malign bone neoplasm after multiple myeloma. Despite systemic chemotherapy, OS may give rise to local recurrences and metastases. Resistance to chemotherapy is not rare and is likely to occur in a high number of patients. Novel therapeutic approaches are required in order to efficiently treat osteosarcoma. Tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) and proteasome inhibitors (epoxomicin, MG132, bortezomib) represent new promising approaches in cancer treatment. The aim of our study is to elucidate the effects of epoxomicin alone or in combination with TRAIL in two TRAIL-resistant OS cell lines, Saos-2 and MG-63 namely. We determined the cytotoxic effects of epoxomicin and/or TRAIL on these two types of OS cells using dimethylthiazolyl 2,5 diphenyltetrazolium bromide (MTT) test and measured apoptosis markers such as pro-apoptotic Bax levels and caspase-3, -8, -9 activities. We used TUNEL assay to demonstrate apoptosis. We investigated dose and time dependent survival rates of OS cells and determined LD50 doses of epoxomicin and TRAIL on OS cell viability after 24, 48, and 72 hour incubations. Concurrent incubation with TRAIL and epoxomicin for 24 hour significantly increased caspase-3, caspase-8, caspase-9 activities and Bax protein levels. Our study demonstrated that the combination of TRAIL with epoxomicin enhances apoptosis, and overcomes TRAIL resistance, denoting promising results for OS therapy in the future.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Ósseas/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Osteossarcoma/patologia , Inibidores de Proteassoma/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Caspases/metabolismo , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Oligopeptídeos/farmacologia , Regulação para Cima , Proteína X Associada a bcl-2/metabolismoRESUMO
OBJECTIVE: The aim of this study was to describe the surgical technique for resection of the distal quarter of the scaphoid and compare the results of patients treated by resection with patients treated by resection with insertion of a pyrocarbon implant. METHODS: The study included 9 wrists treated by resection-only and 8 wrists treated by resection with implant. Average follow-up period was 77 (range: 24 to 130) months. Wrist motion and pinch strength were measured and pain was evaluated using the visual analog scale (VAS). Radiographic classification was performed according to Crosby's classification system and the radiolunate (RL) angle was measured pre- and postoperatively. RESULTS: Postoperative VAS pain scores were 2.1 and 2.6 in the in the resection-only and implant group, respectively. Pain scores decreased significantly in both groups (p=0.007 and p=0.01, respectively). The mean RL angle increased from 14º to 30º in the resection-only group (p=0.008). In the STPI implant group, there was an increase in the mean RL angle from 21º to 23º; however, this difference was not significant (p=0.75). CONCLUSION: Application of a pyrocarbon implant appears to be useful for pain relief and may help prevent secondary deformities in the treatment of scaphotrapezial trapezoidal arthritis.
Assuntos
Artrodese/métodos , Osteoartrite/cirurgia , Osso Escafoide/cirurgia , Articulação do Punho/cirurgia , Idoso , Feminino , Seguimentos , Humanos , Luxações Articulares , Masculino , Pessoa de Meia-Idade , Medição da Dor , Dor Pós-Operatória/diagnóstico , Radiografia , Amplitude de Movimento Articular , Resultado do Tratamento , Articulação do Punho/diagnóstico por imagemRESUMO
OBJECTIVE: Despite wide resection and systemic chemotherapy, bone tumors may present with local recurrences, metastases and pathological fractures. Application of bone cement containing antineoplastic drug to fill the defect after resection of metastatic lesions and to support implants has been suggested to prevent local tumor growth and implant failures. In this study, we aimed to demonstrate the effects of the addition of cisplatin which is a widely used antineoplastic drug for osteosarcoma, on the mechanical properties of bone cement, and to evaluate the cytotoxic effects of eluted cisplatin on Saos-2 cell culture. METHODS: Two cement samples were prepared by mixing 100 mg and 300 mg of cisplatin powder with 40 g cement powder. The bone cement of the control group did not contain cisplatin. Mechanical analyses included 4-point bending, compression and shear testing. For cytotoxicity analysis, samples were incubated in Dulbecco's Modified Eagle's medium for 15 days. Mediums were applied to Saos-2 cell culture and cell viability was measured. Surface analyses were performed by scanning electron microscope (SEM). RESULTS: The addition of cisplatin did not alter the mechanical properties of bone cement. It was observed that the eluted cisplatin had cytotoxic effects on Saos-2 cells. SEM analyses demonstrated cisplatin granules on the surface of cement samples. CONCLUSION: Cisplatin maintains its cytotoxic property when released from bone cement without compromising the mechanical stability. Application of cisplatin loaded bone cement may help local control of tumor growth. We believe that our study will shed light on to these new practices for the treatment of bone cancers and will encourage future studies.
Assuntos
Antineoplásicos/farmacologia , Cimentos Ósseos/química , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Portadores de Fármacos/química , Polimetil Metacrilato/química , Cimentos Ósseos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Osteossarcoma/tratamento farmacológico , Polimetil Metacrilato/farmacologia , Propriedades de SuperfícieRESUMO
Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. Electromyogram (EMG) is beneficial in supporting the diagnosis of CTS. We compared standard nerve conduction studies of EMG with median and ulnar motor nerve conduction studies from recordings of second lumbrical and interosseal muscles in supporting the diagnosis of CTS. In this study, a total of 242 patients were included, and a total of 375 hands were involved. Electrophysiologic CTSs were diagnosed in 283 hands of 161 patients. A significant association between second lumbrical-interosseal distal motor latency difference (2LI-MDLD) and CTS was found in this study. Statistically, every 0.1 increment in the 2LI-MDLD value was observed to increase the risk of disease by 1.74. When a cut-off of ≥ 0.5 for 2LI-MDLD is taken for predicting CTS, the sensitivity of the test is found to be 89.4% and specificity 84.4%. When the cut-off value for motor distal latency of second lumbrical of the median nerve (2L-MDL) was taken as ≥ 3.15 milliseconds in the diagnosis of CTS, the sensitivity of the test was 87.3%, and specificity 70.7%. Previous reports and our findings suggest that in CTS diagnosis, not only 2LI-MDLD value but also 2L-MDL value are easy and rapidly obtainable and offer additional information in very severe cases where compound muscle action potentials (CMAP) cannot be recorded from the abductor pollicis brevis (APB) muscle.