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BACKGROUND: Extraforaminal lumbar disc herniation (EFLDH) accounts for 7%-12% of all lumbar disc herniations. We report on a surgical technique for EFLDH, which requires only minimal resection of the facet joint and also allows access to the preforaminal space, if necessary. METHODS: The medical records of 61 consecutive patients treated with disc fragment herniectomy through a facet joint quadrantectomy for EFLDH at the Universitair Ziekenhuis Brussel were critically evaluated with respect to preoperative clinical signs and symptoms, surgery-related complications and outcome at 6 weeks after intervention. Patient satisfaction after the surgery was evaluated using the MacNab classification. RESULTS: The prevalence of leg pain decreased from 100% before the intervention to 19.7% at follow-up. Only 9 patients (14.8%) suffered from residual motor deficit at follow-up, compared with 37 patients (60.7%) in the preoperative situation. The postoperative improvement was highly significant for all parameters (P < 0.0001) and this evolution is also reflected in the MacNab classification showing 62.3% excellent, 23.0% good, 13.1% fair, and only 1.6% poor satisfaction. Using logistic regression analysis, only the presence of a preoperative sensory deficit was found to be an independent predictor for excellent patient satisfaction on the MacNab classification. CONCLUSIONS: Disc fragment herniectomy through a facet joint quadrantectomy for EFLDH is a safe and minimal invasive technique resulting in very satisfactory results. Preservation of facet joint stability and the possibility to convert to a classic approach to reach for preforaminal components, if necessary, are major advantages of this technique.

Dear Editor, Severe kyphoscoliosis is a deformity with fixed spinal vertebrae that does not allow traction, suspension, or side bending of the spine [1]. Treatment of rigid scoliosis in adults involves correction of complex three-dimensional deformities and restoring balance to the spine but is challenging due to a high rate of associated neurological complications [2]. Spinal cord stimulation (SCS) involves a minimally invasive procedure and might be an alternative pain-relieving therapeutic option with lower risks than spinal correction surgery, especially in patients with increased preoperative risk factors [3]. SCS delivered at 10kHz (HF10) may be preferable over conventional SCS for treatment of back pain [4], but studies examining its use in patients with kyphoscoliosis are lacking. We describe a patient with severe kyphoscoliosis who suffered from back pain for many years but refused spinal correction surgery. A treatment with high-frequency SCS diminished the burden of pain, and the patient was able to return to work. To our knowledge, this is the first report of an “unoperated back” patient who was efficiently treated with high-frequency SCS. A woman age 57 years presented with severe idiopathic kyphoscoliosis and progressive therapy-resistant back pain …

Item does not contain fulltext BACKGROUND: Motor cortex stimulation (MCS) was introduced in the early 1990s by Tsubokawa and his group for patients diagnosed with drug-resistant, central neuropathic pain. Inconsistencies concerning the details of this therapy and its outcomes and poor methodology of most clinical essays divide the neuromodulation society worldwide into "believers" and "nonbelievers." A European expert meeting was organized in Brussels, Belgium by the Benelux Neuromodulation Society in order to develop uniform MCS protocols in the preoperative, intraoperative, and postoperative courses. METHODS: An expert meeting was organized, and a questionnaire was sent out to all the invited participants before this expert meeting. An extensive literature research was conducted in order to enrich the results. RESULTS: Topics that were addressed during the expert meeting were 1) inclusion and exclusion criteria, 2) targeting and methods of stimulation, 3) effects of MCS, and 4) results from the questionnaire. CONCLUSIONS: Substantial commonalities but also important methodologic divergencies emerged from the discussion of MCS experts from 7 European Centers. From this meeting and questionnaire, all participants concluded that there is a need for more homogenous standardized protocols for MCS regarding patient selection, implantation procedure, stimulation parameters, and follow-up-course.

BACKGROUND: The incidence of chronic subdural hematoma (CSDH) is increasing, but optimal treatment remains controversial. Recent meta-analyses suggest burr hole (BH) drainage is the best treatment because it provides optimal balance between recurrence and morbidity. Mini-craniotomy may offer supplementary technical advantages while maintaining equal or better outcomes. This study investigates the outcome of mini-craniotomy as the sole treatment in patients with CSDH. METHOD: We analyzed all patients operated on for CSDH with mini-craniotomy in our neurosurgical center between 2005-2010. Baseline patient characteristics (age, sex, comorbidities, imaging characteristics, known risk factors for development of CSDH and neurological examination at presentation) and outcomes (mortality, complications, recurrence and neurological examination at discharge) were recorded. RESULTS: One hundred twenty-six adult patients were included, mean age was 73.9 (range 18 to 95) years old, and the sex ratio (M:F) was 2:1. Eighty-four percent of the patients showed clinical improvement at discharge, as shown by a decrease in the Markwalder score postoperatively (with 57 % Markwalder 0 and 23 % Markwalder 1). Recurrence rate was 8.7 %. Overall complication rate was 34.1 % (27.8 % medical complications and 6.3 % surgical complications). In-hospital mortality was 13.5 % (8.7 % due to pulmonary infections and 1.6 % to surgical complications). Preoperative Markwalder grade correlated significantly with complication rate, as did the presence of a neurodegenerative disease (p = 0.018). Factors significantly related to mortality in univariate analysis were arterial hypertension (p = 0.038), heart failure (p = 0.02), renal failure (p = 0.017), neurodegenerative disease (p = 0.001), cerebrovascular accident (p = 0.008) and coagulopathy (p = 0.019). Multivariate analysis was not able to confirm any significant relationship. CONCLUSION: This is the first published series of CSDH in which all consecutive patients were operated on by mini-craniotomy. The invasiveness and complication rate of mini-craniotomy are equal to those of burr hole treatment, but visualization is superior, resulting in lower recurrences. A randomized controlled trial is indicated to identify the best surgical strategy for the treatment of CSDH.

Background - Essential hyperhidrosis is characterised by an overactivity of the sympathetic fibres passing through the upper dorsal sympathetic ganglia D2-D3. Anatomical interruption at the D2-D3 level is a highly effective treatment for essential hyperhidrosis but also causes (partial) cardiac denervation and, after surgical sympathicolysis, important impairment of cardiopulmonary exercise function has been observed. The purpose of this study was to compare the results of cardiopulmonary exercise testing between patients with essential hyperhidrosis and a normal control population, and to examine the effects of thoracoscopic D2-D3 sympathicolysis on cardiopulmonary exercise capacity in patients with essential hyperhidrosis. Methods - Maximal, symptom limited incremental exercise tests were performed in 26 patients with severe essential hyperhidrosis one week before and one month after D2-D3 thoracoscopic sympathicolysis, and in 14 age and sex matched healthy volunteers. D2-D3 thoracosopic sympathicolysis was performed using a simplified one stage bilateral procedure. Results - Palmar hyperhidrosis was relieved in every patient, confirming the D2-D3 denervation. A higher peak heart rate (7%) was seen in the patient group than in the normal subjects, but all other cardiovascular, metabolic, and respiratory parameters were similar. After D2-D3 thorascopic sympathicolysis, heart rate at rest (13%) and at peak exercise (7%) were reduced, together with an increase in oxygen pulse. All other parameters remained unchanged. Conclusions - Sympathetic overactivity relevant to cardiovascular function in essential hyperhidrosis is evident only during sympathetic stimulation. D2-D3 thoracoscopic sympathicolysis causes a small and asymptomatic reduction in maximal and resting heart rate and is not associated with a decrease in exercise capacity, in contrast with the detrimental effects on exercise capacity of open surgical sympathectomy.

✓ A case of solitary dorsal intramedullary schwannoma diagnosed by magnetic resonance imaging and treated surgically is reported. The authors review the previously published cases. The possible etiology of the tumor as well as some difficulties encountered in the diagnostic procedure and treatment are discussed.

Essential hyperhidrosis (EH) is caused by an unexplained overactivity of the sympathetic fibers which pass through the upper dorsal sympathetic ganglia D2 and D3. Since the D2 and D3 ganglia are also involved in the sympathetic cardiac innervation, cardiocirculatory autonomic function may also be abnormal in EH. In order to study the function of the sympathetic nervous system in EH, and to assess the effects of thoracoscopic sympathicolysis, cardiocirculatory autonomic function tests were performed in 13 consecutive patients with EH, before (baseline) and 6 weeks after the thoracoscopic intervention. Baseline data were also compared with data obtained from 13 matched healthy volunteers: EH patients showed an increased heart rate at rest, but only in the standing position (94 +/- 18.5 vs 78 +/- 10.9 bpm, P

A simplified one-time bilateral thoracoscopic T2-T3 sympathicolysis technique using single-lumen endotracheal intubation with high frequency jet ventilation and electrocautery destruction ("sympathicolysis") of the sympathetic ganglia was applied in 100 consecutive patients with severe essential hyperhidrosis (EH). Providing a pleural space can be created, this technique was proven simple and safe, and short-term clinical results were excellent: palmar hyperhidrosis was cured in 98% of patients, and axillar and plantar improvement was achieved in 62 and 65% of patients, respectively. Side-effects and complications were minor (compensatory hyperhidrosis) or self-limiting (pain). These data confirm the safety and efficacy of thoracoscopic sympathetic interventions for the treatment of EH, and support the evolution toward simplified methodologies.

Motor cortex electric stimulation has been reported to be effective for the treatment of central post-stroke pain and trigeminal neuropathic pain. Five patients with pain due to injury of the trigeminal nerve and with abnormalities of facial sensibility, as well as two patients suffering of a post-stroke thalamic pain, were subjected to stimulation applied epidurally on the motor cortex. Quadripolar electrodes were implanted under local anaesthesia and the precise location of the motor cortex was determined on three-dimensional surface MRI the day prior to surgery. In our experience, correct topographic localization of the electrode on the motor cortex seems to be crucial to obtain pain reduction.

Motor cortex electric stimulation has been reported to be effective for the treatment of central post-stroke pain and trigeminal neuropathic pain. Five patients with pain due to injury of the trigeminal nerve and with abnormalities of facial sensibility, as well as two patients suffering of a post-stroke thalamic pain, were subjected to stimulation applied epidurally on the motor cortex. Quadripolar electrodes were implanted under local anaesthesia and the precise location of the motor cortex was determined on three-dimentional surface MRI the day prior to surgery. In our experience, correct topographic localization of the electrode on the motor cortex seems to be crucial to obtain pain reduction.

Microdialysis was used to study the biotransformation of L-dopa in intact and denervated striata of rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra. Microdialysis probes were placed in the intact and in the denervated striatum. Observations were then made on freely moving rats. Extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid; HVA) were monitored before, during and after the local administration of L-dopa via the microdialysis probe for 20 min. A dose-dependent increase in extracellular dopamine levels was seen in intact striatum after application of L-dopa in concentrations ranging between 100 nmol/l and 10 mumol/l. In the denervated striatum, the severity of the lesion influenced dopamine formation, so that no dose-effect relation could be established. The effects of the continuous intra striatal infusion of nomifensine, tetrodotoxin or benserazide on the L-dopa-induced dopamine outflow revealed that in the intact striatum this dopamine release is mainly voltage dependent. It was concluded that in the denervated striatum other cells of non-neuronal origin and containing aromatic L-amino acid decarboxylase make a major contribution to the increase in extracellular dopamine levels. Furthermore, L-dopa itself shows no dopamine-releasing properties, at least under the present experimental conditions.

A photochemical technique was used to create central nervous system ischaemia in rats. Changes in blood flow in the spinal cord were assessed by laser Doppler flowmetry. The Th11 spinal cord segment was irradiated by an argon ion laser after intravenous injection of an organic dye, erythrosin B, to rats with or without a laminectomy. In the group of laminectomized rats, laser irradiation for 5 s did not influence cord blood flow, but 10 s irradiation caused a 25% decrease of blood flow, which normalized within 20 min. Decreases of 50 and 80% in spinal cord blood flow were noted after 20 s and after 1 min of laser irradiation, respectively, with no recovery observed after 20 min. In the group of rats without a laminectomy, 1 min of laser irradiation caused approximately a 25% decrease of spinal cord blood flow, which gradually recovered within 12 min, whereas 5 min of laser irradiation caused a more severe reduction of spinal cord blood flow (45 %) with some recovery was observed 30 min later. We could thus confirm that the interaction between a photosensitizing dye and laser irradiation reduced the regional spinal cord blood flow and the extent of this effect could be modified by varying the duration of laser irradiation. The present results therefore provide further support for using this photochemical technique to create animal models of central nervous system ischaemia.

A high-performance liquid chromatographic assay with electrochemical detection is described for the simultaneous determination of levodopa, 3-O-methyldopa, dopamine, dihydroxyphenylacetic acid, homovanillic acid, 3-methoxytyramine, noradrenaline, adrenaline, 3-methoxy-4-hydroxyphenylethylene glycol and 5-hydroxyindoleacetic acid in rat brain dialysates. Samples are obtained in vivo using the microdialysis technique. Microdialysis probes are placed in the brain area to be studied and neurochemicals are collected by perfusion of the probe with modified Ringer's solution. Direct injection of the dialysates allows rapid and reliable results to be obtained.

We have examined the effects of dopamine on prolactin gene expression using quantitative in-situ hybridization histochemistry in different pituitary cell (sub)populations separated according to their density on a discontinuous Percoll gradient. Administration of dopamine resulted in a drastic reduction in hybridization of 35S-labelled DNA probe complementary to prolactin mRNA in total pituitary cells and in lactotrophs with low density. In contrast, dopamine significantly stimulated mRNA accumulation in prolactin-secreting cells with high density compared with other cell layers. The combined use of Percoll gradient and quantitative in-situ hybridization is a valuable and sensitive method with which to examine prolactin-secreting cell response to a given stimulation. Prolactin-secreting cells with high and low density clearly show functional heterogeneity in their response to dopamine. Journal of Endocrinology (1992) 132, 401–409

Microdialysis, in association with ion-pair reversed-phase high-performance liquid chromatography with electrochemical detection, was applied in vitro for the determination and quantification of levodopa and 3-O-methyldopa in blank spiked plasma and blood. The method presented gave accurate results; the calibration graphs for plasma were linear over the range of the expected values for both compounds. When using a dialysis probe with a membrane length of 1.6 cm at a 5 microliters min-1 perfusion speed, the recovery rate in plasma for levodopa was 30.1% and 68.5% for 3-O-methyldopa. However, less reproducible results were obtained for plasma levodopa levels in the range of 0.5 microliter ml-1 and lower. The microdialysis technique was subsequently successfully applied for the continuous intravenous monitoring of levodopa and 3-O-methyldopa in a levodopa-treated dogs.

Electric spinal cord stimulation (SCS) is widely used as a treatment modality for ischemic pain in peripheral arterial insufficiency. The background for the therapeutic effect may be a temporary inhibition of sympathetically maintained peripheral vasoconstriction. In this series of experiments, the involvement of different types of cholinergic and adrenergic receptor subclasses in the vasodilatory effect was explored in anesthetized rats. The microcirculation in hindlimb skin and hamstring muscle was studied by the laser Doppler technique. The ganglionic blocker hexamethonium as well as the nicotinic receptor antagonist chlorisondamine abolished the effect in both vascular beds, whereas the muscarinic receptor antagonists pirenzepine and atropine were ineffective. Among the adrenergic receptor active compounds, phentolamine, prazosine (an alpha 1-receptor antagonist), and clonidine in high doses suppressed the SCS-induced vasodilation. Yohimbine (an alpha 2-receptor antagonist) did not alter the effect. The beta-adrenergic compounds had a differential effect on muscle and skin perfusion. Atenolol, a beta 1-receptor antagonist, inhibited SCS-induced vasodilation only in the skin, whereas the beta 2-receptor antagonist butoxamine selectively depressed the muscle response. The vasodilatory effect of SCS in the animal model used here seems to a large extent to be mediated by an inhibitory effect on peripheral vasoconstriction maintained via efferent sympathetic activity involving nicotinic transmission in the ganglia and the postganglionic alpha 1-adrenoreceptors. The involvement of beta-receptors seems to be different in skin and muscle, beta 1 being more important for the changes in the skin and beta 2 being more important for those in muscle. The high-intensity antidromic response, earlier believed to explain how SCS exerted its vasodilatory effect, was resistant to cholinergic and adrenergic manipulations and seems to depend on entirely different mechanisms.

A combined extraction system for the selective and quantitative isolation of the monoamines norepinephrine, epinephrine, dopamine, serotonin (5-hydroxytryptamine) and their metabolites 3-methoxy-4-hydroxyphenylethylene glycol, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid, homovanillic acid and 3-methoxytyramine from one single brain tissue sample is described. The extraction system is a combination of an ethyl acetate extraction for 3-methoxy-4-hydroxyphenylethylene glycol, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid and homovanillic acid, and two successive ion-pair extractions. In a first step, the catecholamines are quantitatively isolated by extracting with heptane—octanol (99:1) containing 0.25% tetraoctylammonium bromide as an ion-pairing agent in the presence of 0.2% diphenylborate. In a second step, 3-methoxytyramine and 5-hydroxytryptamine are isolated from the aqueous phase with di(2-ethylhexyl)phosphoric acid as counter-ion in chloroform. Dihydroxybenzylamine, isohomovanillic acid and 5-hydroxy-N-methyltryptamine are used as the internal standards.

Data are controversial concerning the time when PRL-synthesizing cells are detected for the first time in the rat pituitary. Using a very sensitive immunocytochemical technique, we could visualize only a few PRL cells before day 10 after birth. At that time, pituitary PRL was still 200 times less abundant than in the adult (on a tissue weight basis) whereas PRL mRNA per mg total RNA was only 80 times lower than in the adult. However, by in situ hybridization, we could demonstrate the presence of PRL mRNA in cells from fetal day 18 on. We have also followed the expression of GH gene in rat pituitary cells during development. In contrast to results obtained with PRL cells, quantitative analysis of cDNA probe hybridization to GH mRNA correlated well with measurements of immunostained cells. We found that PRL was released in the blood from fetal day 19 onwards. Thus, at that time PRL is synthesized and secreted but not stored. We therefore measured brain dopamine levels, and the data support the idea that the rise in dopamine levels after birth contributes to PRL storage. We confirmed in vitro that newborn pituitary cells can store PRL when cultured in the presence of dopamine.

Norepinephrine, epinephrine, dopamine, serotonin and their major catabolites were measured in 17 regions of the left hemisphere of two brains obtained from two brothers with Alzheimer's disease with very early onset. The clinical diagnosis was confirmed by histological examination of the right hemispheres and brain stems. The quantitative data were compared with our values in normal brains. In the patient suffering from the less severe dementia, there was a severe reduction of the serotonin concentration in all examined neocortical areas and its concentration was even below the detection limit in the nucleus amygdalis, hippocampus, caudate nucleus, putamen, globus pallidus and substantia nigra. In the other patient, who suffered from a more pronounced dementia with myoclonus, the serotonin concentration was below the detection limit in all examined structures. In contrast with these findings, the noradrenergic, adrenergic and dopaminergic systems appeared to be relatively unaffected by the disease process. Focusing our attention on the nuclei wherein the monoamine transmitter systems originate, it appeared that neuronal losses and neurofibrillary tangles clearly predominated in the substantia grisea subependymalis, the nucleus centralis superior and the nucleus raphe dorsalis, origin of the main serotonergic system. The serotonin deficiency sheds light on possible mechanisms of myoclonus in Alzheimer's disease.

The concentrations of the acidic dopamine (DA) catabolites homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) measured in human CSF are supposed to reflect the "turnover" of DA in the brain. The notion of "turnover" is, however, not synonymous with impulse nerve activity in the dopaminergic systems. Significant amounts of DOPAC and HVA could, indeed, be demonstrated in brain structures wherein dopaminergic innervation has not been documented. It must also be noted that DA is not only a neurotransmitter itself, but also a precursor of norepinephrine and epinephrine. Furthermore, in lumbar CSF, levels of biogenic amine catabolites partially reflect metabolism in the spinal cord and may have limited relevance to neurotransmission in the brain. To elucidate these points further, we determined the concentrations of DOPAC and HVA in 22 areas of six human brains and eight levels of six human spinal cords. The data were correlated with the concentration of DA. Quantitative determinations were done using HPLC with electrochemical detection, after solvent and ion-pair extraction. In this study, significant amounts of both DOPAC and HVA were demonstrated in brain structures not previously associated with dopaminergic innervation. The relatively lower DA concentration in these structures suggests that in these regions, the DOPAC and HVA concentrations are unrelated to dopaminergic neurotransmission. The possible role of capillary walls and glial cells in the catabolism of DA must be further evaluated. The demonstration of DOPAC and HVA in the spinal cord is another argument against the hypothesis that CSF levels of HVA and DOPAC reflect closely the activity of the dopaminergic systems in the brain.

A combined procedure based on reversed-phase liquid chromatography with electrochemical detection has been developed for the determination in the picomole range of the monoamines dopamine, norepinephrine, epinephrine and serotonin, and their major metabolites 3,4-dihydroxyphenylacetic acid, homovanillic acid, 3-methoxy-4-hydroxyphenylethylene glycol, 5-hydroxyindoleacetic acid, normetanephrine, metanephrine and 3-methoxytyramine. Sample pretreatment consists of the extraction of the neutral and acidic metabolites with ethyl acetate, followed by the extraction into heptane of the catecholamines with tetraoctylammonium bromide as counter-ion in the presence of diphenylborate. The residual supernatant is directly injected in the chromatographic system for quantification of serotonin, normetanephrine, metanephrine and 3-methoxytyramine.

We performed neurochemical quantitation of the catecholamines dopamine (DA), norepinephrine (NE) and epinephrine (E) and their major metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) in 22 cortical regions of 6 postmortem human brains. Statistical analysis indicated a clear regional difference for NE and E while DA and all the metabolites under study are homogeneously distributed over the cortex. These consistent regional differences suggest the possible role of NE and E as neurotransmitters or neuromodulators in human cerebral cortex.

Chronic intramuscular injections, particularly of narcotic analgesics, are an uncommon cause of myopathy. We report two patients with pentazocine- and meperidine-related myopathy. Narcotic-induced muscular fibrosis and contractures must be considered in patients with a pattern of muscle involvement that does not conform to any recognized myopathy, but allows for self-administration of injections. Trauma due to needle puncture, repetitive infections and a local myotoxic effect of the drugs probably contribute to these lesions.

Two patients presenting a relapsing form of sporadic brachial plexus neuropathy, the so-called Parsonage Turner syndrome, are reported. The diagnosis is based on clinical and electromyographic features. Recurrent attacks, although infrequently encountered, have been well described in the past. Sporadic cases of this syndrome must be differentiated from the familial varieties of neuralgic amyotrophy in which, two main subgroups of patients are distinguished: those showing facial dysmorphic features and those with findings of a tomaculous neuropathy predisposing them to pressure palsies. Apart from the obvious difference as regards familial occurrence, the familial and non-familial varieties of neuralgic amyotrophy differ in a number of respects: associated congenital defects, early age of onset and high rate of recurrence in the former. Finally some possible pathogenetic mechanisms of the syndrome are briefly reviewed.