Jefferson Becker

What symptoms are truly caused by median nerve compression in carpal tunnel syndrome

OBJECTIVE This study aims to identify the symptoms, signs and distributions which are associated with neurophysiological carpal tunnel syndrome (N-CTS), defined by the finding of a median nerve lesion at the wrist through neurophysiologic studies, and to compare them with those of patients with sensory or motor complaints in the upper limbs whose electrophysiologic investigation did not show evidence of this syndrome. METHODS A cross-sectional study was performed, with prospective gathering of data, following a predetermined protocol. We included all patients older than 12 years who were referred for nerve conduction studies and electromyography of at least one of the upper limbs between August 2001 and January 2003. The patients answered a clinicoepidemiologic questionnaire and painted the areas in which they felt pain and those in which they felt paresthesia, and were also examined to test for classical signs CTS. RESULTS A neurophysiological diagnosis of CTS was reached in 1549 upper limbs (39%). Approximately 6% of the upper limbs with N-CTS and 16% of those without median nerve lesion do not have any hand or wrist symptoms (P<0.001). Paresthesia, pain, hand weakness and cramps were the symptoms statistically associated to N-CTS, with paresthesia being the one with the greatest power of association. This is usually felt in median innervations territory, and is frequently extended to the whole hand, but without association with N-CTS when felt in proximal region. CONCLUSIONS One concludes that the most characteristic manifestation of carpal tunnel syndrome (CTS) is paresthesia. Pain also occurs very frequently but it is less specific, and weakness, meanwhile, seems to have a low frequency. We believe that the variability in the clinical presentation of CTS is largely due to the presence of associated diseases and our results provide information which could help to better define the clinical criteria used in the diagnosis of this syndrome.

Prediction of the neurophysiological diagnosis of carpal tunnel syndrome from the demographic and clinical data

OBJECTIVE To use demographic and clinical data to identify the clinical pattern that best predicts the diagnosis of carpal tunnel syndrome (CTS), as defined by neurophysiologic studies. METHODS A diagnostic cross-sectional study in 2535 consecutive patients (3907 upper limbs) older than 12 years old who were referred for nerve conduction studies in the upper limbs between August 2001 and January 2003 in 3 university hospitals and 2 private neurophysiology services in the state of Rio Grande do Sul, Brazil. RESULTS A neurophysiologic diagnosis of CTS was established in 39.1% of these upper limbs. The presence of paresthesias or pain at least 2 of the first 4 digits in association with one of the following: female gender, symptoms worsening at night or on awakening, an BMI > or =30, thenar atrophy, or other sign (Tinels, Phalens, or Reversed Phalens signs); were the best pattern associated with the diagnosis. CONCLUSIONS We have found that the clinical picture alone does not seem sufficient, in majority of the population, to correctly predict the diagnosis of CTS, as defined by median nerve neuropathy at the carpal tunnel. We believe that a compressive lesion of the median nerve at the carpal tunnel can be present both in patients with no typical symptoms of CTS (including asymptomatic individuals) and in patients in which neurophysiologic studies are negative. SIGNIFICANCE Further studies separating patients into these groups will allow us to identify the long-term prognosis as well as the ideal therapeutic approach for each of these clinical situations.

Rhabdomyolysis: a genetic perspective

Rhabdomyolysis (RM) is a clinical emergency characterized by fulminant skeletal muscle damage and release of intracellular muscle components into the blood stream leading to myoglobinuria and, in severe cases, acute renal failure. Apart from trauma, a wide range of causes have been reported including drug abuse and infections. Underlying genetic disorders are also a cause of RM and can often pose a diagnostic challenge, considering their marked heterogeneity and comparative rarity.In this paper we review the range of rare genetic defects known to be associated with RM. Each gene has been reviewed for the following: clinical phenotype, typical triggers for RM and recommended diagnostic approach. The purpose of this review is to highlight the most important features associated with specific genetic defects in order to aid the diagnosis of patients presenting with hereditary causes of recurrent RM.Abstract in PortugueseA rabdomiólise (RM) é um evento agudo e grave, caracterizado por danos do músculo esquelético com a liberação, em grande quantidade, de componentes intracelulares para a corrente sanguínea. Uma vasta gama de causas tem sido relatada, incluindo trauma, abuso de drogas e infecções. Doenças hereditárias também podem causar RM, mas muitas vezes representam um desafio diagnóstico, considerando a sua heterogeneidade e raridade. Por fim, diversas doenças neuromusculares costumam estar associadas com níveis de CK cronicamente elevados, dificultando a identificação correta dos episódios de RM.Nesse artigo, revisamos os diversos defeitos genéticos associados à RM. Cada gene foi revisado abrangendo os seguintes: fenótipo clínico, gatilhos para RM e abordagem diagnóstica. O objetivo desta revisão é destacar as características mais importantes associados a defeitos genéticos específicos, a fim de auxiliar o diagnóstico de pacientes com causas hereditárias de RM recorrente.

Th17 Cells Pathways in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders: Pathophysiological and Therapeutic Implications

Several animal and human studies have implicated CD4+ T helper 17 (Th17) cells and their downstream pathways in the pathogenesis of central nervous system (CNS) autoimmunity in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), challenging the traditional Th1-Th2 paradigm. Th17 cells can efficiently cross the blood-brain barrier using alternate ways from Th1 cells, promote its disruption, and induce the activation of other inflammatory cells in the CNS. A number of environmental factors modulate the activity of Th17 pathways, so changes in the diet, exposure to infections, and other environmental factors can potentially change the risk of development of autoimmunity. Currently, new drugs targeting specific points of the Th17 pathways are already being tested in clinical trials and provide basis for the development of biomarkers to monitor disease activity. Herein, we review the key findings supporting the relevance of the Th17 pathways in the pathogenesis of MS and NMOSD, as well as their potential role as therapeutic targets in the treatment of immune-mediated CNS disorders.

Hypocalcemic myopathy without tetany due to idiopathic hypoparathyroidism: case report

UNLABELLED Myopathy due to idiopathic hypoparathyroidism is very unusual. We report on a 30 years-old man referred with complaints of sporadic muscle pain and mild global weakness for 10 years. His physical examination showed normal strength in distal muscle and slightly weakness in the pelvic and scapular girdles with no atrophy. Deep muscle reflexes were slightly hypoactive. Trousseaus and Chvosteks signs were absent. He had bilateral cataract and complex partial seizures. His laboratory tests showed decreased ionised and total calcium and parathyroid hormone and increased muscle enzymes. EMG and muscle biopsy was compatible with metabolic myopathy. After treatment with calcium and vitamin D supplementation he showed clinical, neurophysiological and laboratorial improvement. IN CONCLUSION patients with muscle symptoms, even when non-specific and with normal neurological examination, should have serum calcium checked, as myopathy due to idiopathic hypoparathyroidism, even being rare, is treatable and easy to diagnose.

Prevalence of amyotrophic lateral sclerosis in the city of Porto Alegre, in Southern Brazil

OBJECTIVE To determine the prevalence of amyotrophic lateral sclerosis (ALS) in the city of Porto Alegre, Brazil. METHOD We conducted an extensive investigation in clinics and hospitals that provide specialized assistance to these patients, contacted neurologists and the regional association of people with ALS. RESULTS On July 31, 2010, 70 patients were alive and diagnosed with amyotrophic lateral sclerosis. Considering the population living in the city in the same period (1,409,351), the estimated prevalence was 5.0 cases per 100,000 people (95% CI, 3.9-6.2), being higher for men (5.2/100,000 95% CI, 3.6-7.2) than for women (4.8/100,000 95% CI, 3.4-6.5). The prevalence increased with age peaking in the age group 70-79 years in both genders. CONCLUSION The prevalence of ALS in the city of Porto Alegre is similar to that reported in other parts of the world.

Muscle architecture and torque production in stroke survivors: an observational study

Objective: Spasticity poststroke leads to muscle weakness and soft tissue contracture, however, it is not clear how muscle properties change due this motor neural disorder. The purpose was to compare medial gastrocnemius muscle architecture and mechanical properties of the plantarflexor muscles between stroke survivors with spasticity and healthy subjects. Methods: The study included 15 stroke survivors with ankle spasticity and 15 healthy subjects. An isokinetic dynamometer was used for the evaluation of maximal isometric plantarflexor torque and images of the medial gastrocnemius muscle were obtained using ultrasonography. Images were collected at rest and during a maximum voluntary contraction. Results: The affected limb showed reduced fascicle excursion (0.9 ± 0.7 cm), shorter fascicle length, and reduced muscle thickness (0.095 ± 0.010% of leg length and 1.18 ± 0.20 cm, at rest) compared to contralateral (1.6 ± 0.4 cm, 0.106 ± 0.015% of leg length and 1.29 ± 0.24 cm, respectively) and to healthy participants (1.8 ± 0.7 cm, 0.121 ± 0.019% of leg length and 1.43 ± 0.22 cm, respectively). The contralateral limb showed lower force (between 32 and 40%) and similar architecture parameters compared to healthy participants. Conclusion: The affected limb had a different muscle architecture that appears to result in lower force production. The contralateral limb showed a decrease in force compared to healthy participants due to the other neural impairments than muscle morphology. Spasticity likely leds to adaptations of muscle architecture in the affected limb and in force reductions in both limbs of stroke survivors.

Seasonal variation in prevalence of carpal tunnel syndrome

Introduction: The influence of cold temperatures on neuropathies has been reported previously, but its impact on carpal tunnel syndrome (CTS) is not well analyzed. Methods: We analyzed the frequency of CTS among neurophysiological evaluations according to seasonal variation in 9574 consecutive patients (4260 with CTS). Results: A higher frequency of CTS was found in the winter (50.8%), and the lowest number for CTS diagnosis was found in the summer (38.9%). In both autumn and spring the prevalence remained stable at an intermediate level between summer and winter at 42.8% and 43.5%, respectively. Conclusion: CTS frequency was much higher in winter in this center. Muscle Nerve 47: 925–927, 2013

Hypovitaminosis D association with disease activity in relapsing remitting multiple sclerosis in Brazil

Multiple sclerosis (MS) onset is believed to result from a combination of environmental and genetic factors. A prevailing theory addresses the influence of hypovitaminosis D in the development of MS. This research aimed to study the association between vitamin D serum levels and MS, as a prognostic and risk factor for the development and progression of the disease. A cross-sectional multicenter study was conducted in patients with relapsing-remitting MS (n=67), according to the revised McDonald criteria (2010), accompanied in three MS centers in different Brazilian states. A control group consisted of healthy volunteers (n=61). Blood collections were carried out in late summer and late winter. This seems to be the first study of this kind in Latin America. The vitamin D serum levels for MS patients (29.63±8.08) in summer were similar to the controls (29.71±8.28); however, in winter they were lower than the healthy individuals (24.05±7.47 vs 26.56±8.01). No significant difference between the three cities was observed. No association was noted between vitamin D serum levels and gender, race and age, nor correlation of these levels with the EDSS or disease duration. In contrast, a significant association was seen between deficient vitamin D serum levels in late winter with disease activity, characterized by the onset of relapses (19.73±5.69 vs 25.30±6.22) or Gd+ lesions (17.22±3.11 vs 22.79±7.22).

Nearly one-half of Brazilian patients with multiple sclerosis using natalizumab are DNA-JC virus positive

OBJECTIVE Natalizumab is a new and efficient treatment for multiple sclerosis (MS). The risk of developing progressive multifocal leukoencephalopathy (PML) during the use of this drug has created the need for better comprehension of JC virus (JCV) infection. The objective of the present study was to assess the prevalence of JCV-DNA in Brazilian patients using natalizumab. METHOD Qualitative detection of the JCV in the serum was performed with real-time polymerase chain reaction (PCR). RESULTS In a group of 168 patients with MS who were undergoing treatment with natalizumab, JCV-DNA was detectable in 86 (51.2%) patients. DISCUSSION Data on JCV-DNA in Brazil add to the worldwide assessment of the prevalence of the JCV in MS patients requiring treatment with natalizumab.