Advances in the treatment of neuropathic pain with hyperbaric oxygen.

Neuropathic pain (NPP) refers to the pain caused by primary or secondary injury or dysfunction of the peripheral or central nervous system, and usually requires multidisciplinary treatment. However, most pharmacological and non-pharmacological interventions can only temporarily and/or moderately improve pain-related symptoms, and they often produce unbearable adverse reactions or cause drug resistance. Hyperbaric oxygen (HBO2) therapy has been widely used in the clinical treatment of some diseases due to its advantages of safety, few side effects, no resistance, and non-invasiveness. In recent years, increasing numbers of basic and clinical studies have been conducted to investigate the efficacy and mechanism of HBO2 in the treatment of NPP, and great progress has been made in this field. In this paper, we briefly introduce the pathogenesis of NPP and therapeutic effects of HBO2 and summarize the mechanisms underlying the effects of HBO2 in treating NPP, which may provide reference for the clinical treatment of pain with HBO2.

Mi experiencia clínica con efalizumab en el Hospital de Conxo / My clinical experience with efalizumab in the Hospital of Conxo

La psoriasis en placas es una enfermedad crónica que en sus formas moderadas y graves precisa tratamiento sistémico. La necesidad de tratamiento, generalmente prolongado, hace que muchos medicamentos indicados para el tratamiento de la psoriasis no puedan ser utilizados de forma continuada y tengan que ser sustituidos por otros fármacos diferentes pero también con un uso limitado, tanto por sus posibles efectos secundarios, como por su teratogenicidad, el tiempo de uso y la dosis acumulada, entre otros motivos. Los fármacos biológicos han sido diseñados para el control a medio y largo plazo de la enfermedad. Efalizumab es un medicamento que se ha demostrado eficaz y seguro en los pacientes que presentan una psoriasis moderada a grave. Presentamos nuestros resultados en un grupo de 50 pacientes, nuestros casos especiales, la forma en que hemos tratado los efectos secundarios debidos a efalizumab y los debidos a la enfermedad (AU)

Psoriasis in plaques is a chronic disease that requires systemic treatment in its moderate and severe forms. Because the need for treatment is generally prolonged, many medications indicated for its treatment cannot be used continuously and have to be replaced by other different drugs, but also with a limited use, both due to their possible side effects, their teratogenicity, the time of use and accumulated dose, among other reasons. The biological drugs have been designed for middle and long term control of the disease. Efalizumab is a drug that has been shown to be effective and safe in patients who have moderate-to-severe psoriasis. We present our results in a group of 50 patients, our special cases, the form in which we have treated the side effects due to Efalizumab and those due to the disease (AU)

A neuronal correlate of secondary hyperalgesia in the rat spinal dorsal horn is submodality selective and facilitated by supraspinal influence.

Tissue injury produces hyperalgesia not only in the injured area (primary hyperalgesia) but also outside of it (secondary hyperalgesia). In the present investigation, the submodality selectivity and the contribution of supraspinal influence to a neural correlate of the secondary hyperalgesia induced by neurogenic inflammation was studied in the presumed pain relay neurons of the rat spinal dorsal horn. Mechanically and thermally evoked responses to wide-dynamic range (WDR) neurons of the spinal dorsal horn were recorded under sodium pentobarbital anesthesia in rats. Neurogenic inflammation was induced by application of mustard oil outside of the receptive fields of WDR neurons. To study the contribution of supraspinal influence to mustard oil-induced changes in neuronal responses, the spinal cord was transected at a midthoracic level or lidocaine was microinjected into the rostroventromedial medulla (RVM). Furthermore, the antidromically evoked compound volley in the sural nerve was determined to reveal excitability changes in the central terminals of primary afferent A-fibers induced by mustard oil. The results indicate that mustard oil adjacent to the receptive fields of spinal WDR neurons significantly enhanced their responses to mechanical but not to noxious heat stimuli, without a significant influence on their spontaneous activity. Both high- and low-threshold mechanoreceptive input to WDR neurons was equally facilitated, whereas mechanoreceptive input to spinal dorsal horn neurons mediating innocuous messages (low-threshold mechanoreceptive neurons) was not changed. Mustard oil in a remote site (forepaw) did not produce any hyperexcitability to responses evoked by hindpaw stimulation. Spinal transection or lidocaine block of the RVM significantly attenuated the mustard oil-induced mechanical hyperexcitability in spinal dorsal horn neurons. Mustard oil had no significant effect on a compound volley in the sural nerve induced by intraspinal stimulation of sural nerve terminals at a submaximal intensity. The selective mechanical hyperexcitability in spinal WDR neurons, without a change in their spontaneous activity, can be explained by a heterosynaptic facilitatory action on presynaptic terminals mediating mechanical signals to these nociceptive spinal neurons. These findings indicate that brain stem-spinal pathways, involving the RVM, do not only suppress nociception but under some pathophysiological conditions concurrent facilitatory influence may predominate and lead to enhancement of mechanical hyperexcitability. The descending facilitatory feed-back loop to nociceptive spinal neurons may help to protect the wounded tissue and thus promote healing.

Absent vestibular evoked myogenic potentials in vestibular neurolabyrinthitis. An indicator of inferior vestibular nerve involvement?

BACKGROUND: Benign paroxysmal positioning vertigo (BPPV) is generally thought to be caused by canalolithiasis in the posterior semicircular canal, an organ that is innervated by the inferior vestibular nerve. We hypothesized that absent vestibular evoked myogenic potentials (VEMPs) would indicate involvement of the inferior vestibular nerve and that posterior semicircular canal-type BPPV could not develop after vestibular neurolabyrinthitis (VNL) in patients with absent VEMPs. OBJECTIVE: To find out if VEMPs could be helpful in evaluating involvement of the inferior vestibular nerve in acute VNL. DESIGN: We reviewed the VEMP findings in 47 patients (34 men and 13 women) with acute VNL, 10 of whom had then developed posterior semicircular canal-type BPPV. RESULTS: While p13-n23, the first positive-negative peak of the VEMP, was ipsilaterally present on stimulation of the unaffected side in all patients, it was absent on the affected side in 16 patients (34%). The absence or presence of p13-n23 was independent of the results of caloric tests, pure tone audiometry, and auditory brain-stem responses. Typical posterior semicircular canal BPPV developed in 10 of the 47 patients after the acute attack of VNL, always on the same side as the neurolabyrinthitis. The p13-n23 potentials were preserved on stimulation of the affected ear in all 10 patients with BPPV. CONCLUSIONS: These results suggest that if VEMPs are absent from an ear that has suffered acute VNL, then posterior semicircular canal BPPV is unlikely to develop as a consequence of the VNL. The reason for this appears to be that the absence of VEMPs is due to involvement of the inferior vestibular nerve or involvement of the structures that it innervates.

[The role of activation of lipid peroxidation of the tissues in response of the body to nociceptive stimuli]. / Rol' aktivatsii perekisnogo okisleniia lipidov tkanei v reaktsii organizma na notsitseptivnye stimuly.

Taking into consideration that activation of free radical processes is an indispensable consequence of any extreme action on man and animals and that lipid peroxidation (LPO) metabolites may play a role of original "primary mediators of stress", an attempt was made to define LPO participation in body response to nociceptive stimuli. Investigations carried out in patients belonging to different nosological groups, differing in the intensity of pain, established the presence of a direct relationship between the potency of painful action and LPO activation. LPO activation was also observed in experiments on animals exposed to painful tourniquetting of the limbs. The data obtained allowed a conclusion about possible participation of free radical lipid peroxidation processes in the formation of nociception. This may be confirmed by the circumstance that reflexotherapy determined remarkable LPO activation together with removal of the painful syndrome.

Encephalomyeloneuropathy with ganglionitis of the myenteric plexuses in the absence of cancer.

A 55-year-old woman presented with rapidly progressive brainstem dysfunction which led to death within a month. She also had constipation for three weeks, and barium enema showed ileus. Subacute encephalomyelitis predominantly involving the medulla and pons correlated with the patient's initial symptoms. In addition, ganglionitis of the myenteric plexuses explained the constipation and ileus. Ganglioradiculoneuropathy was another finding. The presence of abundant neuronophagia in the brainstem, dorsal root ganglia, and myenteric plexuses raised the speculation that a putative virus, toxic agent, or immune reaction possessed special affinity for neurons and ganglion cells. The neuropathological findings were similar to paraneoplastic changes, but no neoplasm was found.

[Effect of electrostimulation of the medial portion of the hypothalamus of cats on features of sciatic nerve fiber restructuring in experimental neuritis]. / Vliianie élektrostimuliatsii srednego otdela gipotalamusa koshek na osobennosti perestroika nervnykh volokon sedalishchnogo nerva pri éksperimental'nom nevrite.

In order to study the processes of rearrangement in nerve fibers of the ischiatic nerve and its nervi nervorum at experimentally induced neuritis, the middle part of the hypothalamus was electrically stimulated in 74 mature cats. Twenty three cats were electrically stimulated with alternating current of a rectangular form, 50 Hz 1 m/sec, 1.5 V, for 30 min on each side of the hypothalamic subtubercle. Seven days after electrode implantation, the experimental neuritis was produced by inserting aseptic mica plates subepineurally into the ischiatic nerve. Samples of the nerve stem were taken from the traumatized area and histological sections and film preparations were made. The material was treated after Foot, Ramon y Cajal, Rasskazova, Bielschowsky-Gross-Kampos, Sokoliansky, McManus. As demonstrated the analysis of the preparations, at early stages of the experiments the nerve fibers were preserved better under the electrostimulation than in the intact hypothalamus. However, by the 60th day, resulting from the pathology of the diencephalon, some distrophic changes developed in the peripheral nerve. Lateral branching processes were forming on the axonal cylinders. Nervi nervorum were spreading and forming long and dense wrappings around the endoneural sheaths where they terminated with loops simulating Perroncito's spirals.