Spinal cord stimulation in chronic pain: evidence and theory for mechanisms of action.

Well-established in the field of bioelectronic medicine, Spinal Cord Stimulation (SCS) offers an implantable, non-pharmacologic treatment for patients with intractable chronic pain conditions. Chronic pain is a widely heterogenous syndrome with regard to both pathophysiology and the resultant phenotype. Despite advances in our understanding of SCS-mediated antinociception, there still exists limited evidence clarifying the pathways recruited when patterned electric pulses are applied to the epidural space. The rapid clinical implementation of novel SCS methods including burst, high frequency and dorsal root ganglion SCS has provided the clinician with multiple options to treat refractory chronic pain. While compelling evidence for safety and efficacy exists in support of these novel paradigms, our understanding of their mechanisms of action (MOA) dramatically lags behind clinical data. In this review, we reconstruct the available basic science and clinical literature that offers support for mechanisms of both paresthesia spinal cord stimulation (P-SCS) and paresthesia-free spinal cord stimulation (PF-SCS). While P-SCS has been heavily examined since its inception, PF-SCS paradigms have recently been clinically approved with the support of limited preclinical research. Thus, wide knowledge gaps exist between their clinical efficacy and MOA. To close this gap, many rich investigative avenues for both P-SCS and PF-SCS are underway, which will further open the door for paradigm optimization, adjunctive therapies and new indications for SCS. As our understanding of these mechanisms evolves, clinicians will be empowered with the possibility of improving patient care using SCS to selectively target specific pathophysiological processes in chronic pain.

Diffuse hepatic haemangiomatosis: A case report and review of literature

@#Hepatic haemangioma is a solitary liver lesion and prevalent among the female patients. We report a case of diffuse hepatic haemangiomatosis in a 62-year-old man, who was referred for an incidental finding of multiple liver nodules. History and physical examinations were unremarkable. Computed tomography and magnetic resonance imaging of the liver were performed and showed multiple haemangiomatosis. In view of the rarity of this condition in men, a liver biopsy was done and confirmed haemangiomas. Available published literature on diffuse hepatic haemangiomatosis was reviewed.

Inflammation During Gestation Induced Spatial Memory and Learning Deficits: Attenuated by Physical Exercise in Juvenile Rats.

BACKGROUND: Gestational infections induced inflammation (GIII) is a cause of various postnatal neurological deficits in developing countries. Such intra uterine insults could result in persistent learning-memory disabilities. There are no studies elucidating the efficacy of adolescence exercise on spatial learning- memory abilities of young adult rats pre-exposed to inflammatory insult during fetal life. AIMS AND OBJECTIVES: The present study addresses the efficacy of physical (running) exercise during adolescent period in attenuating spatial memory deficits induced by exposure to GIII in rats. MATERIALS AND METHODS: Pregnant Wistar dams were randomly divided into control and lipopolysaccharide (LPS) groups, injected intra peritoneally (i.p) with saline (0.5ml) or lipopolysaccharide (LPS) (0.5mg/kg) on alternate days from gestation day 14 (GD 14) till delivery. After parturition, pups were divided into 3 groups (n=6/group) a) Sham control and LPS group divided into 2 subgroups- b) LPS and c) LPS exercise group. Running exercise was given only to LPS exercise group during postnatal days (PNDs) 30 to 60 (15min/day). Spatial learning and memory performance was assessed by Morris water maze test (MWM), on postnatal day 61 to 67 in all groups. RESULTS: Young rats pre-exposed to GIII and subjected to running exercise through juvenile period displayed significant decrease in latency to reach escape platform and spent significant duration in target quadrant in MWM test, compared to age matched LPS group. Results of the current study demonstrated that exercise through juvenile/adolescent period effectively mitigates gestational inflammation-induced cognitive deficits in young adult rats. CONCLUSION: Inflammation during gestation impairs offspring's spatial memory and learning abilities. Whereas, early postnatal physical exercise attenuates, to higher extent, cognitive impairment resulted from exposure to LPS induced inflammation during intrauterine growth period.

Protective effect of light emitting diode phototherapy on fluorescent light induced retinal damage in Wistar strain albino rats.

BACKGROUND: Artificial light at night alters retinal physiology. Several studies have shown that light emitting diode phototherapy protects the retina from the damaging effects of acute light exposure. OBJECTIVE: The aim of this study has been to elucidate the protective effects of 670 nm LED light on retinal damage induced by chronic fluorescent light in Wistar rats. METHODS: Male Wistar albino rats were divided into four groups: group 1 were control (CL), group 2, 3 and 4 were exposed to fluorescent light (FL), LED preexposure+fluorescent light exposure (LL) and only LED light exposure (OL) respectively. All animals were maintained in their specific exposure regime for 30 days. Fluorescent light of 1800 lx was exposed between 8 pm to 8 am. Rats were exposed to therapeutic LED light of 670 nm of 9 J/cm2 at 25 mW/cm2 for 6 min duration. Histopathological changes in the retina were studied. RESULTS: Animals of the FL group showed a significant reduction in the outer nuclear layer thickness and cell count in addition to the total thickness of the retina. LL group which were exposed to 670 nm LED prior to exposure to fluorescent light showed a significant decrease in the degree of damage. CONCLUSIONS: 670 nm LED light preexposure is protective to retinal cells against fluorescent light-induced damage.

Abnormal branching pattern of the axillary artery and its clinical significance / Patrón de ramificación anormal de la arteria axilar y su significado clínico

The increasing use of invasive diagnostic and interventional procedures in cardiovascular diseases makes it important that the type and frequency of vascular variations are well documented and understood. Sound knowledge of neurovascular variations is important for surgeons who remove axillary lymph nodes, to anesthesiologists, and orthopedic surgeons, considering the frequency of procedures done in this region. An unusual variation in the branching pattern of axillary artery was observed on the left side of a 60 year old female cadaver. In the present case the course and distribution of the first and second part of the axillary artery were normal. But a rare case of unusual origin of subscapular, anterior and posterior circumflex humeral, profunda brachii artery and ulnar collateral arteries from a common trunk were found on the left side during routine dissection. This common trunk was found arising from the third part of the axillary artery and at its commencement it was found passing between the two roots of the median nerve. Cases with this kind of variations should be examined or operated carefully during surgical or electrophysiological procedures.

El incremento del uso de diagnósticos invasivos y procedimientos de intervención en las enfermedades cardiovasculares hace que sea importante que el tipo y la frecuencia de las variaciones vasculares estén bien documentados y entendidos. Un buen conocimiento de las variaciones neurovasculares es importante para los cirujanos que extirpan linfonodos axilares, para anestesiólogos y cirujanos ortopédicos, considerando la frecuencia de los procedimientos realizados en esta región. Una inusual variación en el patrón de ramificación de la arteria axilar se observó en el lado izquierdo de un cadáver de sexo femenino de 60 años de edad. En el presente caso, el curso y la distribución de la primera y segunda parte de la arteria axilar fueron normales. Sin embargo, fue encontrado en el lado izquierdo, durante la disección de rutina, un caso raro, de origen inusual, de las arterias subescapular cirunflejas humerales anterior y posterior, braquial profunda y arterias colaterales ulnares desde un tronco común. Este tronco común se encontró derivado de la tercera parte de la arteria axilar y en su comienzo se comprobó que pasaba entre las dos raíces del nervio mediano. Los casos con este tipo de variaciones deben ser examinados u operados cuidadosamente durante procedimientos quirúrgicos o electro fisiológicos.

Effect of diagnostic ultrasound during the fetal period on learning and memory in mice.

BACKGROUND: An experiment was conducted to find out whether in utero exposure to diagnostic ultrasound leads to changes in postnatal behavior in adult mice. METHODS: A total of 15 pregnant Swiss albino mice were exposed to diagnostic levels of ultrasound (3.5 MHz, 65 mW/cm(2), intensity((spatial peak-temporal peak)) (I(SPTP))=1 mW/cm(2), intensity((spatial average-temporal average)) (I(SATA))=240 mW/cm(2)) for 30 min on day 14 or 16 of gestation. All exposed as well as control animals were left to complete gestation and parturition. Their offspring were used in our further studies. They were monitored during early postnatal life for standard developmental markers (such as pinna detachment, eye opening and fur development) and postnatal mortality was recorded up to 6 weeks of age. The litters were subjected to behavioral tests for learning and memory at 4 months of age. Representative animals from each group were sacrificed and the hippocampal region of the brain was assayed for biogenic amines, noradrenaline, dopamine, serotonin (5-HT) and 5-HT's metabolite, 5-hydroxy indoleacetic acid (5-HIAA), in order to determine whether ultrasound exposure produced any biochemical changes in the hippocampal region of the brain. Coronal sections from the dorsal hippocampus from the representative animals from each group were processed for staining and the number of neurons was counted. RESULTS: Neither the standard developmental markers (such as pinna detachment, eye opening and fur development) nor the postnatal mortality was affected by ultrasound exposure. However, there was a significant impairment in learning (hole board test) and memory functions (shuttle box test) in both the exposure groups. Significant reductions in the biogenic amines and the decrease in the neuronal density were found only in day 14th pc ultrasound-exposed group compared with the control animals. The 16th day exposure group is relatively resistant to ultrasound-induced impairment of brain functions. CONCLUSIONS: The results suggest that the early fetal brain is highly susceptible to induction of neurobehavioral changes by ultrasound exposure.

Variation in the Origin of Sternocleidomastoid Muscle: A Case Report / Variación en el Origen del Músculo Esternocleidomastoideo: Reporte de Caso

A rare case of additional slip in the origin of the clavicular head of sternocleidomastoid muscle was found during our routine dissection, on both sides of the neck in an elderly male cadaver. However, on both side of the same muscle no such additional slip of origin was found at the sternal head of the sternocleidomastoid near its origin nor at its insertion of the muscle.

Durante una disección de rutina, fue encontrado un raro caso de un fascículo adicional en el origen de la cabeza clavicular del músculo esternocleidomastoideo, en ambos lados del cuello, en un cadáver de un anciano de sexo masculino. Sin embargo, en ambos lados, no se encontró un fascículo adicional en el origen de la cabeza esternal ni en la inserción del músculo esternocleidomastoideo.

Ectopic Thyroid Tissue With a Rare Vascular Variation / Tejido Tiroideo Ectópico con una Rara Variación Vascular

Awareness of the variations and anomalous existence of some structures serve as useful guide for both in studies of human anatomy and in clinical practice today. Identification of ectopic thyroid tissue and variations in origin, number and course of the branches of the superior thyroid artery are of significant practical importance for the general, vascular surgeons and radiologist. Angiographic images with such vascular patterns may lead to confusion in interpretation. The relations of these vessels with the other structures are important for accurate diagnostic and invasive techniques and to prevent further complications during surgical interventions. In our routine dissections with the purpose of preparation of the teaching and museum specimens, it was observed that in one of the elderly male cadaver showed median thyroid tissue at a site other than in its usual pretracheal region. It was situated in the median plane extending from the hyoid bone to the front of cricoid cartilage. Normal thyroid gland in the pretracheal region was absent. Added to this rare anomaly a vascular anomaly was found in the same ectopic thyroid tissue. Solely the superior thyroid arteries supplied this median thyroid tissue. The inferior thyroid arteries were found to be absent on both sides supplying this median thyroid tissue.

Conocer la existencia de variaciones y anomalías de algunas estructuras, sirve usualmente como guía para estudios de anatomía humana y práctica clínica. La identificación de tejido tiroideo ectópico y variaciones en origen, número y curso de ramas de la arteria tiroidea superior son, por lo general, de importancia práctica significativa para cirujanos vasculares y radiólogos. Imágenes angiográficas con tales patrones vasculares pueden llevar a confusión en su interpretación. La relación de estos vasos con otras estructuras son importantes en un diagnóstico acucioso, en técnicas invasivas y para prevenir complicaciones durante intervenciones quirúrgicas. En una disección de rutina, con el propósito de preparar piezas anatómicas de museo para la enseñanza, se observó en un cadáver de sexo masculino, tejido tiroideo mediano en un sitio diferente a la región pretraqueal. Estaba situado en el plano mediano extendiéndose desde el hueso hiodes a la parte anterior del cartflago cricoides. La glándula tiroides normal en la región pretraqueal estuvo ausente. Agregada a estainusual variación, una rara anomalía vascular fue encontrada en el mismo tejido tiroideo ectópico, sólo las arterias tiroideas superiores irrigaban este tejido tiroideo mediano. No se encontraron arterias tiroideas inferiores irrigando este tejido.