Tourette's Syndrome cervical dystonia induced occipital neuralgia remedied by peripheral nerve stimulation: A case report / Síndrome de Tourette, distonia cervical induzida por neuralgia occipital remediada por estimulação nervosa periférica: relato de caso

BACKGROUND: Dystonia is uncommon in Tourette's syndrome, and occipital neuralgia secondary to Tourette's dystonia is more rare, affecting quality of life. Occipital peripheral nerve stimulation (PNS) is an excellent alternative by being adjustable and minimally invasive. Our case demonstrates occipital PNS as an effective option for refractory Tourette's dystonia. CASE PRESENTATION: A thirty-four-year-old male with poorly controlled Tourette's cervical dystonia presented with severe occipital neuralgia. Various medications were prescribed including propranolol and amitriptyline, and bilateral third-occipital nerve rhizotomies and occipital nerve blocks were trialed. Distal nerve blocks at the occipital protuberance were most effective. Therefore, an occipital PNS trial was done, and a PNS was implanted with no complications. Upon follow-up, the patient reported drastic pain reduction. CONCLUSION: Our case illustrates neuromodulation benefits for a rare presentation of refractory occipital neuralgia secondary to Tourette's-related dystonia. Occipital PNS should be considered for refractory cases because it is safe, easy to implant, and effective.

FUNDAMENTO: A distonia é incomum na síndrome de Tourette, e a neuralgia occipital secundária à distonia de Tourette é mais rara, afetando a qualidade de vida. A estimulação do nervo periférico occipital (SNP) é uma excelente alternativa por ser ajustável e minimamente invasiva. Nosso caso demonstra o SNP occipital como uma opção eficaz para a distonia de Tourette refratária. APRESENTAÇÃO DO CASO: Um homem de 34 anos com distonia cervical de Tourette mal controlada apresentou neuralgia occipital grave. Vários medicamentos foram prescritos, incluindo propranolol e amitriptilina, e foram testadas rizotomias bilaterais do nervo terceiro-occipital e bloqueios do nervo occipital. Os bloqueios dos nervos distais na protuberância occipital foram mais eficazes. Portanto, foi feito um ensaio de PNS occipital e um PNS foi implantado sem complicações. Após o acompanhamento, o paciente relatou redução drástica da dor. CONCLUSÃO: Nosso caso ilustra os benefícios da neuromodulação para uma apresentação rara de neuralgia occipital refratária secundária à distonia relacionada a Tourette. O PNS occipital deve ser considerado para casos refratários porque é seguro, fácil de implantar e eficaz.

Study of the potential toxicity of adrenaline to neurons, using the SH-SY5Y human cellular model

Abstract Prolonged overexposure to catecholamines causes toxicity, usually credited to continuous adrenoceptor stimulation, autoxidation, and the formation of reactive pro-oxidant species. Non-differentiated SH-SY5Y cells were used to study the possible contribution of oxidative stress in adrenaline (ADR)-induced neurotoxicity, as a model to predict the toxicity of this catecholamine to peripheral nerves. Cells were exposed to several concentrations of ADR (0.1, 0.25, 0.5 and 1mM) and two cytotoxicity assays [lactate dehydrogenase (LDH) release and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction] were performed at several time-points (24, 48, and 96h). The cytotoxicity of ADR was concentration- and time-dependent in both assays, since the lowest concentration tested (0.1mM) also caused significant cytotoxicity at 96h. N-acetyl-cysteine (1mM), a precursor of glutathione synthesis, prevented ADR-induced toxicity elicited by 0.5mM and 0.25mM ADR following a 96-h exposure, while the antioxidant Tiron (100µM) was non-protective. In conclusion, ADR led to mitochondrial distress and ultimately cell death in non-differentiated SH-SY5Y cells, possibly because of ADR oxidation products. The involvement of such processes in the catecholamine-induced peripheral neuropathy requires further analysis.

The Effect of Anakinra on Acrylamide-induced Peripheral Neuropathy and Neuropathic Pain in Rats

Abstract Acrylamide is a neurotoxic compound. Moreover, anakinra is an interleukin-1 (IL-1) receptor antagonist used in rheumatoid arthritis treatment. This study investigated the effect of anakinra on acrylamide-related neuropathy and neuropathic pain. Acrylamide exposure caused a significant decrease in the pain threshold; an increase in malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß) levels; and a decrease in total glutathione (tGSH) values in the sciatic nerve. This indicates hyperalgesia presence, oxidative stress, and peripheral nerve tissue inflammation. Anakinra treatment significantly reduced the MDA, IL-1ß, and TNF-α levels, and increased the pain threshold and mean tGSH values. The analgesic effect of anakinra was 67.9% at the first hour, increasing to 74.9% and 76.7% at the second and third hours, respectively. The group receiving acrylamide exhibited histopathological changes (e.g., swollen and degenerated axons, hypertrophic and hyperplasic Schwann cells, and congested vessels). The use of anakinra significantly improved these morphological changes. Anakinra is concluded to reduce neuropathic pain and prevent neurotoxic effect of acrylamide on peripheral nerves due to its analgesic, antioxidant, and anti-inflammatory properties

Plexopatía braquial secundaria a tumor maligno de la vaina del nervio periférico / Brachial plexopathy secondary a malignant tumor of the peripheral nerve sheath

Introducción: el plexo braquial puede verse afectado por patología neoplásica tanto primaria como secundaria. Los tumores primarios del plexo braquial son entidades poco frecuentes, aunque algunos, como el tumor maligno de la vaina del nervio periférico pueden tener un comportamiento agresivo. Caso clínico: se presenta una mujer de 31 años con disestesias y debilidad progresiva en el miembro superior izquierdo. El estudio neurofisiológico mostró afectación del plexo braquial izquierdo. En la resonancia magnética se observó una masa de tejido blando que invadía el plexo braquial. El estudio histológico fue compatible con un tumor maligno de la vaina del nervio periférico. Conclusiones: el tumor maligno de la vaina del nervio periférico es un tumor altamente agresivo que puede aparecer en pacientes sin datos clínicos de neurofibromatosis tipo 1. Debe mantenerse un elevado nivel de sospecha con el objetivo de no retrasar el diagnóstico para así poder realizar un tratamiento lo más conservador posible.

Introduction. Malignant peripheral nerve sheath tumor (MPNST) are sarcomas that are rarely located in the upper limb. Clinical case. We present a 31- year-old woman with progressive dysesthesia and weakness of the left upper limb. The neurophysiological study showed damage in the left brachial plexus. A soft tissue mass that was invading the plexus was observed in the magnetic resonance image. The anatomopathological study was compatible with MPNST diagnosis. Conclusions. Intrinsic tumors of the brachial plexus are uncommon. A MPNST is an extremely aggressive mesenchymal tumor that is seldom rooted in the brachial plexus.

Electrophysiological Evaluation of the Incidence of Martin-Gruber Anastomosis in Healthy Subjects

The Martin - Gruber Anastomosis (MGA) is probably the most well known of the anastomotic anomalies that occur at various levels between the median and ulnar nerves. It is formed by motor axons from the median nerve or its branch anterior interosseous nerve that cross in the upper forearm to join the ulnar nerve. The purpose of this study was to establish the frequency of MGA in healthy subjects and to draw the attention of clinicians working in the neurophysiological laboratory to the presence of this anastomosis, and thus to avoid possible misinterpretations of data from needle electromyography (EMG) and nerve conduction studies. 100 volunteers (60 women and 40 men) were selected for the study. Surface recording electrodes were placed on the right hand thenar, hypothenar and on the first dorsal interosseous (FDI) muscles. The median and ulnar nerves were stimulated supramaximally at the wrist and at the elbow and compound muscle action potentials (CMAPs) were recorded and their amplitudes evaluated. MGA was found in 27 of the 100 subjects. The type of anastomosis most frequently seen was type II, which was observed in 21 subjects. Type I anastomosis was observed in three, type I + type II in two and type III anastomosis in one subject. It can thus be concluded that MGA is frequently encountered and it should be borne in mind that abnormal innervation models may influence the electrophysiological findings and thus give rise to faulty interpretations, especially in the case of median and ulnar nerve lesions.

Electromiografía y velocidad de conducción nerviosa / Electromyography and neural conduction velocity

Electromiografía es el estudio clínico del potencial de acción de la actividad elétrica del músculo esquelético, recogida por medio de un electrodo de aguja. Se describe la aplicación clínica en los procesos miopáticos y neurogénicos. Complemento de este estudio es la velocidad de conducción nerviosa (VCN), tanto periférica como sensorial. Requiere de la aplicación de un estímulo eléctrico en el nervio que se desea explorar, obteniendo la respuesta en el tendón del nervio inervado por ese nervio. La conducción nerviosa sensorial se obtiene estimulando un nervio mixto o cutáneo. La aplicación clínica tanto de la conducción motora como sensorial, es para localizar alteraciones del nervio periférico, enfermedades musculares y neuromusculares