Long-term clinical, electrophysiological and urodynamic effects of chronic intrathecal baclofen infusion for treatment of spinal spasticity

Seventeen patients with severe disabling spinal spasticity were selected and treated by chronic intrathecal baclofen infusion using an implanted programmable pump. Nine patients were tetraparetic, seven were paraplegic and one paraparetic. Patients were regularly followed for 5 to 69 months (mean 37.5 months). The clinical efficacy of baclofen was estimated by means of evaluation of: hypertonia, spasms, pain and functional disability. All patients experienced significant amelioration of quality of life secondary to reduction of hypertonia, spasms and pain related to contractures. Neurogenic pain improved in 3 cases and remained unchanged in 3 others. In patients whose motor functions were partially preserved, various degrees of motor improvement were detected. Electrophysiological recordings of Polysynaptic flexion reflexes (FR) were obtained to control conditions, and under intrathecal baclofen, in order to quantify the spinal excitability responsible for spontaneous or induced spasms. Flexion reflex threshold was increased and amplitude proved to be very significantly reduced by chronic baclofen infusion in all our patients. Twelve patients with neurogenic bladder dysfunction were also evaluated by a clinically oriented questionnaire and by quantitative urodynamic recordings, before and after pump implantation. In patients with normal micturition, this was not changed by intrathecal baclofen. In patients with spastic bladder, intrathecal baclofen produced a decrease of detrusor hypertonia and hyperactivity in 50% of cases, with reduction of leakage and increase in functional bladder capacity.

Anatomical findings in microsurgical vascular decompression for trigeminal neuralgia. Correlations between topography of pain and site of the neuro-vascular conflict

We here report on the anatomical findings in a series of 350 patients with trigeminal neuralgia (TN) and operated on using a microsurgical key-hole approach to the CPA. In 5.7% there was a tumour or a vascular malformation, in 2.3% a mega-vertebro-basilar-artery. Among the remaining 322 (= real idiopathic TN), only 3.1% had no visible compressive factor, whilst 96.9% had one (or several) conflicting vessel(s): SCA in 90%, AICA in 23.6%, a vein in 24.7%. In 35.7% of the patients, several neurovascular conflicts (NVC) were found. Beside the NVC(s), a global atrophy of the entire root was seen in 67% of the cases. Degree of severity of the NVC and its site along the root were studied. The site of the conflict was: anteriorly to the root when pain was in V1, anteriorly and superiorly when in V2, superiorly and posteriorly when in V3.

[Neurosurgical treatments of chronic pain]

During these last years the methods and the indications of analgesic neurosurgery have respectively changed toward greater multiplicity and more selectivity. The conservative methods of neurostimulation have acquired a prominent place in some types of pain from neuropathic origin. Their aim is to reinforce inhibitory fibre function. Whatever the technique used, stimulation of peripheral nerves, of posterior funiculi of the spinal cord, of the thalamus or the cerebral cortex, it will be effective only if the target structures are not totally, anatomically and functionally, destroyed. Intrathecal morphine administration, has been shown to be useful to control some cancer-induced pain. Lastly, the techniques of interrupting the pathways of pain, achieving greater selectivity in their effects, remain the preferred treatment for some types of localised pain having precise mechanisms.

Effect of antibiotic therapy on the antibiotic resistance of faecal Escherichia coli in patients attending general practitioners

To analyse the influence of antibiotic therapy on the faecal flora of patients from general practice with complaints of a respiratory tract infection (RTI), 189 paired faecal specimens were collected, before and after completing antibiotic treatment (n = 129) and symptomatic treatment (n = 60). Faecal specimens were examined for the prevalence and degree of resistance to amoxycillin, apramycin, ciprofloxacin, nalidixic acid, neomycin, nitrofurantoin, oxytetracycline, sulphamethoxazole and trimethoprim. In the antibiotic-treated group a significant increase in the prevalence of resistance to amoxycillin post-treatment from 50% to 64% (P < 0.05, Wilcoxon) was observed. In the symptomatic treated group no significant differences in the prevalence of resistance were found. Using discriminant analysis, amoxycillin and doxycycline therapy contributed to an increased prevalence of resistance to amoxycillin and oxytetracycline, respectively. In the antibiotic-treated group Escherichia coli isolates post-treatment had a significantly increased resistance rate to amoxycillin (15%-23%) and to neomycin (2%-6%) (P < 0.05, Wilcoxon). Logistic regression analysis showed a cross resistance to neomycin and kanamycin, and for kanamycin cross-resistance to apramycin, neomycin and streptomycin occurred.

[Veterinary surveillance in animal shelters--defects and potentials]

Looking after the stock of local animal shelters takes a considerable part of the field of activity of veterinarians. Because of the recent situation on the job market it is of interest for the veterinary profession to provide and extend this scope of duties. In order to give a comprehensive survey of the possibilities of curative and preventive herd advising in animal shelters, 369 managers of German animals shelters were asked to answer a questionnaire containing 92 answers, concerning the situation in the animal shelter. The answers of 144 animal shelters go to prove the following results. In 41% of the animal shelters veterinarians are visiting for rounds in regular intervals, 46% of the shelters are calling the veterinarians only if needed. 1% of the animal shelters bring sick animals into the clinic and 1% does not provide any medical care for the animals. At the moment 11% of the questioned animal shelters offer positions for veterinarians. In these case a significantly better, mainly preventive medical care is found compared to shelters without regular medical care. Deworming (98%) and vaccinations (91%) are provided routinely for dogs being brought to the animal shelter recently. In 46% of the animal shelters employees vaccinate dogs during the absence of a veterinarian. Therefore, 36% of the animal shelters bring new dogs into contact with the others without a soundness examination. Even though 60% of the animal shelters dispose quarantine units, dogs are only isolated for 7 days in average in 15% of the animal shelters. The most common disease of dogs in animal shelters is diarrhoea.(ABSTRACT TRUNCATED AT 250 WORDS)

Tropism of serotonergic neurons towards glial targets in the rat ependyma

During development, recognition mechanisms between neurons and their targets are necessary for the formation of the neuronal network. Neural connections are synaptic or non-junctional. Both types of communication can be found between neurons and glial elements in the periventricular walls. Serotonergic fibers form synaptic contacts on the specialized ependymocytes of the subcommissural organ, a structure which forms the roof of the third ventricle at its junction with the aqueduct. A network of non-junctional fibers containing both GABA and serotonin spread between the cilia of the classical ependymocytes in the ventricles. These anatomical, morphological and biochemical features suggest a tropism and specific recognition mechanisms between glial elements and serotonergic neurons. This hypothesis can be tested by the study of the innervation of the subcommissural organ and the classical ependyma by grafted embryonic neurons after a chemical destruction of the serotonergic endogenous innervation. Solid implants or cell suspensions prepared from embryonic metencephalon were transplanted to either the third ventricle or the periventricular gray matter in 5,7-dihydroxytryptamine denervated rats. Grafted serotonergic neurons were able to reinnervate the classical ependyma and the subcommissural organ. The fibers forming the supraependymal plexus were non-junctional and contained both serotonin and GABA while those innervating the subcommissural organ formed synaptic contacts and contained only serotonin. The signals capable of inducing the ependymal innervation were specific for serotonergic neurons since catecholaminergic neurons present in the grafts were unable to innervate either classical or specialized ependymocytes. These results demonstrate that glial cells are targets for serotonergic neurons and that the morphological and biochemical characteristics of the serotonergic innervation are closely related to the target cell phenotype.

Synthesis of recombinant baculoviruses expressing the outer capsid protein VP2 of five BTV serotypes and the induction of neutralizing antibodies to homologous and heterologous BTV serotypes

DNA representing RNA segment L2 of 5 different bluetongue virus (BTV) serotypes (BTV-1, -2, -11, -13 and -17) corresponding to the gene that codes for the BTV neutralization antigen VP2, have been inserted individually into baculovirus transfer vectors in lieu of the 5' coding region of the polyhedrin gene of Autographa california nuclear polyhedrosis virus (AcNPV). After co-transfection of Spodoptera frugiperda cells with wild-type AcNPV DNA in the presence of the derived transfer vector DNAs, polyhedrin-negative recombinant baculoviruses were recovered. When S. frugiperda cells were infected with each of these viruses, protein was made similar in size and antigenic properties to the authentic BTV VP2 protein. To evaluate the biological activities of these proteins, antibodies were raised to them in guinea pigs. The neutralization capabilities of these antisera were tested against homologous and, for two of the higher titered sera, heterologous BTV serotypes. Each antiserum neutralized the infectivity of the homologous virus serotype. In heterologous virus challenges, the serum raised to the VP2 protein of BTV-13 also neutralized the infectivity of BTV-1, and to lesser extents BTV-3, -16, -8 and -9 (BTV-2, -10, -11, -15 were not tested). The serum raised to the VP2 of BTV-17 neutralized BTV-20 and -21, and to lesser extents BTV-4 and -8 (again, BTV-2, -10, -11, -15 were not tested).

Inhibition of chondrogenesis and endochondral mineralization in vitro by different calcium channel blockers

Limb bud mesenchymal cells from mouse embryos grown at high density at the medium/air interphase undergo chondrogenesis and form numerous nodules of mature cartilage. Addition of beta-glycerophosphate (5 mM) induced endochondral mineralization within these nodules. Ca2+ accumulation, matrix formation and alkaline phosphatase activity were recorded for each culture. Treatment with the L-type channel-specific blockers nifedipine and verapamil during the entire culture period caused an inhibition of mineralization. Sequential treatment reduced mineralization only when added during the early part of the culture period in the course of chondrogenesis. In all cases, matrix formation, estimated by alcian blue binding, was concomitantly diminished. Lanthanum acetate, which blocks Ca2+ channels non-specifically, also reduced Ca2+ accumulation in the cultures when added continuously. After sequential treatment, Ca2+ content was only diminished when the cultures were treated in the last part of the culture period during mineralization. Matrix formation was not altered by lanthanum acetate, but alkaline phosphatase was decreased. These results show that chondrogenic differentiation is under control of L-type Ca2+ channels, whereas matrix calcification depends on intracellular Ca2+ accumulation mediated by lanthanum-sensitive Ca2+ channels. This points to the importance of intracellular Ca2+ accumulation in the process of endochondral mineralization.

Anatomical findings observed during microsurgical approaches of the cerebellopontine angle for vascular decompression in trigeminal neuralgia (350 cases)

The authors report the anatomical pathological findings collected from 1979 to 1992 in a series of 350 consecutive patients referred because of apparently idiopathic trigeminal neuralgia (TN) and operated on using a microsurgical keyhole approach of the cerebellopontine angle. In 20 cases (5.7%) the cause of the TN was a tumor or a vascular malformation, in 8 (2.3%) an atherosclerotic huge vertebrobasilar artery, all actually corresponding to symptomatic TN. Among the 322 others (= real idiopathic TN), only 10 (3.1%) had no visible compressive factor whilst 312 (96.9%) had one (or several) conflicting vessel(s): superior cerebellar artery in 90%, anterior inferior cerebellar artery in 23.6%, and a vein in 24.7%. In 35.7% of the patients, several neurovascular compressions (NVC) were found in association. Site(s) along the root, location around its surface and degree of severity of the conflicts were carefully studied. Of prime importance is the fact that, beside the localized lesions due to the NVC(s), a moderate to marked global atrophy of the entire root was frequently seen (in 67% of the cases) indicating that the NVC might not be the sole pathogenetic agent of the disease.

Intraoperative monitoring of spinal cord SEPs during microsurgical DREZotomy (MDT) for pain, spasticity and hyperactive bladder

Since 1972, MDT has been performed in 234 patients with chronic pain, 140 with hyperspasticity and 12 with hyperactive neurogenic bladder. In the last 64 patients, the evoked electrospinogram has been recorded intraoperatively from the surface of the spinal cord, to monitor the electrophysiological effects produced by the surgical lesioning, not only on the conduction of lemniscal fibers when entering the dorsal column, but also on the postsynaptic responses of the dorsal horn cells. The decrease in amplitude of the latter responses (N13 or N22) was well correlated with (1) the depth and the width of the DREZ lesion, and (2) the number of spinal segments operated on. In most cases, amplitude was reduced in the order of 2/3, which was considered the best value.

The effect of sustained phonation at high and low pitch on vocal jitter and shimmer

Looking for possible signs of vocal fatigue, acoustic waveform perturbation was measured in normal female subjects during sustained phonation at various fundamental frequencies (Fo). At none of the pitch levels a rise of the jitter or the shimmer was found after 25 min of vocalization. On the other hand, an effect of Fo was seen from the start: above the habitual speaking Fo of our subjects' voices there was a tendency for the jitter to be higher and for the shimmer to be lower.

Microsurgical vascular decompression (MVD) in trigeminal and glosso-vago-pharyngeal neuralgias. A twenty year experience

Report of the results of treatment in 1380 cases with trigeminal neuralgia and 14 cases with glosso-vago-pharyngeal neuralgia. Trigeminal neuralgia was treated by percutaneous thermorhizotomy in 960 cases and by open micro-approach to the cerebellopontine angle in 420 cases. In cases treated by microsurgical vascular decompression, cure rate was 91%, partial relief 5%, failure 4%. Recurrence occurred in 6%. Glossopharyngial neuralgia was treated by percutaneous thermocoagulation of the Andersch ganglion in 3 cases and by a direct approach to the jugular foramen in 11 cases, in 9 of them with micro-vascular decompression. With microsurgical vascular decompression, all cases had total pain relief without recurrence.

Does microsurgical vascular decompression for trigeminal neuralgia work through a neo-compressive mechanism? Anatomical-surgical evidence for a decompressive effect

The positive effect of Microsurgical Vascular Decompression (MVD) on idiopathic trigeminal neuralgia still remains controversial between a decompressive mechanism and a "neo-compressive" one. This paper is a summary of a comparative study of the results on pain obtained with two technical modifications of the MVD procedure. The first consisted of interposition of a foreign material between the nerve and the transposed artery after dissection of the trigeminal nerve, whilst in the second the offending vessel(s) was dislodged without using any material touching the nerve. The two series of 60 patients in each were similar concerning the clinical features. Evaluation of results on neuralgia - with one year follow-up-in both series, shows that the technique used in the second group was not followed by a higher rate of recurrence than the technique used in the first group. On the contrary; 4.5% in the 2nd group compared to 10% in the first. This indicates that MVD would not act as a result of "neo-compression" of the nerve, but rather through a real decompressive mechanism.

Ablative neurosurgical procedures for the treatment of chronic pain

This article is devoted to ablative neurosurgical procedures used for the treatment of chronic pain. The authors detail only those procedures that are currently performed. The procedures are classified as those directed to the peripheral nerves, spinal roots and cranial nerves; the dorsal root entry zone; the ascending extra-lemniscal pathways. The authors have analyzed the results of their own series and those published in the literature. They concentrate on the rationale and neurophysiological effects of the operations.

Microsurgical ablative procedures in the peripheral nerves and dorsal root entry zone for relief of focal spasticity in the limbs

When spasticity is harmful and localized in the limb(s), ablative procedures in the peripheral nerves or the dorsal root entry zone (DREZ) can be useful. The authors report on the long-term results of (1) selective tibial neurotomy in a series of 62 spastic feet, and (2) microsurgical DREZ-tomy in a series of 69 patients affected with hyperspasticity in the entire upper or lower limb(s).

Pericallosal aneurysms

The authors report a series of 19 patients with one (17 cases) or two (2 cases) pericallosal aneurysms referred during the past 10 years. Of the 19 patients, 18 had a ruptured pericallosal aneurysm and one was asymptomatic. On admission two were graded I, four graded II, six graded III, and six graded IV. Of the latter group two patients died from rebleeding, and the asymptomatic patient would not undergo surgery. The 16 operated patients underwent surgery after a delay ranging from 6 to 90 days after hemorrhage (25 days on average). The delayed surgery allowed the patients to be operated on in better neurological status: seven were graded I or Ia, six graded II, three graded III, and none graded IV. The results were excellent (with resumption of their previous activity) in 11 cases (69%), good (autonomous but with a slight deficit) in 4 cases (25%), and bad in 1 case (6%). There was no operative mortality or morbidity.

Selective neurotomy of the tibial nerve for treatment of the spastic foot

One of the most frequent neurological sequelae seen by the specialist in rehabilitation is the spastic foot. Spasticity in the foot may be responsible for abnormal posture and painful or trophic disturbances impairing standing and walking. This disability can be corrected by a simple neurosurgical procedure, the selective tibial neurotomy. In this procedure, one sections the tibial nerve branches to the muscles sustaining spasticity, i.e., the soleus and/or the gastrocnemius nerves for equinus and ankle clonus or the posterior tibialis branch for varus and the flexor fascicles for tonic flexion of the toes. After microsurgical dissection of each tibial nerve branch at the lower part of the popliteal region and their identification with bipolar electrostimulation, the selected branches are partially sectioned under the operating microscope. The present series consists of 62 operations performed in 53 patients, 9 bilaterally and 44 unilaterally. Operation obtained complete suppression of the disabling spasticity that had been present for 2 to 17 years (4 on average), total pain relief, and consequently improvement of the residual voluntary movements (by achieving a better balance between agonist and antagonist muscles) in 51 of the 62 spastic feet (i.e., 82% of the cases). For all of these patients, the beneficial effects were long-lasting over the 1- to 10-year follow-up (3 years on average). Selective neurotomy of the tibial nerve should be considered only after failure of intensive prolonged kinestherapy and of all available medical treatment. It must take place, however, before the onset of irreversible articular disturbances and musculotendinous retractions, which require complementary orthopedic corrections.

Choroid plexectomy for the treatment of chronic infected hydrocephalus

Choroid plexectomy was performed for chronic infected hydrocephalus in 17 children via a direct open approach. In 16 cases, the CSF was sterilized soon after the plexectomy. In 37% of cases, the hydrocephalus was arrested without a shunt. The incidence of seizures did not increase after plexectomy. Removal of the choroid plexus was controlled by scintigraphy. Neuropsychological results were not encouraging, probably related to the long history of chronic ventricular infection. Surgical mortality was 6%. Choroid plexectomy should be considered as a possible treatment of chronic infected hydrocephalus in children.

A simple model of VA/Q distribution for analysis of inert gas elimination data

A general procedure for fitting compartments models of alveolar ventilation-perfusion ratio (VA/Q) distribution to inert gas elimination data is described. The method can be applied to any model consisting of a number of compartments ventilated and perfused in parallel, each compartment of the model having a fixed predetermined VA/Q ratio. The number of compartments and their VA/Q ratios required for adequately fitting real data have been examined. A 13-compartment model consisting of a shunt, a dead space, and 11 compartments equally spaced on a logarithmic scale from VA/Q of 0.01 to 100 was found to be suitable. The fitting procedure and the 13-compartment model form the basis of a method of analysis of inert gas elimination data. Essentially the method consists of calculating a sample of 30 distributions compatible with the data analyzed taking into account experimental errors in the inert gas measurements. From this sample, the averages and standard deviations of the flows to 13 zones on the VA/Q scale are estimated. The averages are estimates of the true flows to these zones, and the standard deviations give an indication of the range of flows compatible with the data. The method has some advantages over both the enforced-smoothing approach and the Monte Carlo linear programming scheme of Evans and Wagner (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 42: 889-898, 1977).

Improvement in ventilation-perfusion matching by almitrine in COPD

Almitrine, a peripheral chemoreceptor stimulating drug, was given 100 mg orally to six patients with advanced chronic obstructive pulmonary disease (COPD), and its effects on hemodynamics, blood gases, lung mechanics, and the distribution of ventilation/perfusion ratios (VA/Q), determined by the inert gas elimination technique, were investigated. Arterial Po2 increased from 52 +/- 4 to 59 +/- 3 mm Hg, mean +/- SEM, p less than 0.01, arterial Pco2 decreased from 46 +/- 3 to 43 +/- 3 mm Hg, p less than 0.05, and venous admixture from 30 +/- 6 to 19 +/- 3 percent, p less than 0.02. No change occurred in ventilation, variables of lung mechanics, systemic and pulmonary hemodynamics, except an increase in pulmonary vascular resistance (from 364 +/- 103 to 438 +/- 99 dyne.s.cm-5, p less than 0.05). A reduction in VA/Q inequality could be demonstrated with a redistribution of blood flow into the lungs by a diversion of 15 percent of total blood flow from units with low VA/Q (between 0.08 and 0.4) to units with normal VA/Q (between 0.5 and 1.8). These changes might be explained by an enhancement of hypoxic pulmonary vasoconstriction. Pharmacologic peripheral chemoreceptor stimulation, at an infra-ventilatory analeptic dosage, might be of therapeutic interest to patients with respiratory insufficiency due to VA/Q inequality.