Spontaneous neuronal hyperactivity in the medial and intralaminar thalamic nuclei of patients with deafferentation pain

Electrical activity was recorded from single cells in the thalamus of 10 patients with chronic pain associated with deafferentation. Under local anesthesia, these patients underwent either electrode implantation or thalamotomy for treatment of their pain. In eight of the 10 patients, single units were identified as discharging spontaneously in high-frequency, often rhythmic, bursts. The discharges were of two types: short bursts comprised of two to six spikes with a burst frequency of one to four per second; and long trains of 30 to 80 spikes of similar frequency. Reconstruction of electrode trajectories indicated that recordings were made from the region corresponding to the lateral aspect of the mediodorsal thalamic nucleus, the central lateral nucleus, a small part of the central median nucleus, and the parafascicular nucleus. In the eight patients in whom spontaneous neuronal burst activity was exhibited, it was impossible to study activity evoked by natural cutaneous stimulation due to the continuous spontaneous neuronal discharges. Both animal and human studies have suggested that pain related to deafferentation is accompanied by spontaneous hyperactivity in the dorsal horn of the spinal cord and in the ventral posterior thalamic nuclei. The authors present evidence of spontaneous neuronal hyperactivity in the intralaminar thalamic nuclei of patients with pain related to deafferentation. The findings suggest that spontaneous neuronal discharge in patients with pain related to deafferentation is more widespread in the central nervous system than has been previously appreciated. The results have important implications for the surgical treatment of chronic pain.     

Dissociated mesencephalic responses to medial and ventral thalamic nuclei stimulation in rats. Relationship to analgesic mechanisms

To investigate the mechanism of analgesia noted with electrical stimulation of the thalamic sensory relay nucleus and medial thalamus, modulations of neuronal activities in the periaqueductal gray matter (PAG) were studied in response to electrical stimulations of the ventroposterolateral nucleus (VPL) and parafascicular nucleus (Pf) and to peripheral noxious stimulations in rats. Extracellular single-unit activities were recorded from 102 neurons in the PAG and the adjacent area in animals under halothane anesthesia. A large population (83%) of the PAG neurons reacted to Pf stimulations with a predominantly excitatory response, whereas smaller numbers (43%) responded to VPL stimulations. There was a significant correlation between the response characteristics of Pf and noxious stimulations, whereas no correlation was found between VPL and noxious stimulations. The PAG neurons that were verified antidromically to project to the nucleus raphe magnus showed a similar pattern of response. The excitatory response to the Pf stimulation was partially attenuated by systemic administration of naloxone, whereas that to the VPL stimulation was not affected. These results suggest that part of the analgesic mechanism of medial thalamus stimulation involves activation of the descending pain suppression system by exciting the PAG neurons through the opioid system, while the analgesia produced by sensory relay nucleus stimulation does not involve the PAG neurons or the opioid system.     

Convergent and complementary projections of the caudal paralaminar thalamic nuclei to rat temporal and insular cortex

Thalamic nuclei adjacent to the medial geniculate body play a pivotal role in processing of sensory stimuli during emotional situations. These nuclei, which include the suprageniculate nucleus (SG), the posterior intralaminar nucleus (PIN), the peripeduncular nucleus (PP) and the medial division of the medial geniculate body (MGm), project to both cortex and amygdala, but target areas and the extent of the projection of individual nuclei are not known yet. The aim of the present study was to analyze the contribution of individual nuclei to the cortical projection with modern sensitive tracing techniques. Small injections of Miniruby or PHA-L were made into single thalamic nuclei. All thalamic nuclei have in common a projection into the upper portion of layer I of the temporal aspect of the cortical mantle. Furthermore, SG, PIN, MGm and PP each demonstrated a convergent projection to lower layer III and to layer IV of the ectorhinal and visceral cortex. Only MGm projects to layer VI of primary auditory and temporal association cortices. Within the perirhinal cortex zones of convergence and divergence exist. The present results demonstrate a differential thalamocortical projection of single thalamic nuclei to those cortical areas which are involved in the transmission of sensory signals to the amygdala via the thalamocortico-cortical pathway and to the hippocampus via the entorhinal cortex. The thalamic nuclei are thus in a position to activate the amygdala and to modulate the information flow of the thalamocortico-cortical pathway to both amygdala and hippocampus.     

Pathologic changes in biliary dyskinesia

Purpose

For children with upper abdominal pain and evaluation for acalculous biliary disease, laparoscopic cholecystectomy is an accepted treatment with inconsistent outcomes. The purpose of this study was to identify predictors of outcomes.

Methods

One hundred sixty-seven children underwent laparoscopic cholecystectomy at a single children's hospital. Radiographic findings, histopathology, family history, and demographics (sex, age, height, weight, body mass index-for-age percentile) were evaluated as predictors of postoperative symptomatic resolution using a binomial probability model. The data for radiologic studies and pathologic specimens were obtained via re-review in a blinded fashion.

Results

Of 167 children, 43 (25.7%) had a preoperative diagnosis of biliary dyskinesia and 41 (95.3%) had documented follow-up. Mean follow-up was 8.4 months. Twenty-eight patients (68.3%) had symptom resolution. Ejection fraction less than or equal to 15%, pain upon cholecystokinin injection, and a family history of biliary disease were not predictors of symptomatic resolution. Nonoverweight patients (body mass index-for-age <85th percentile) were more likely to have symptom resolution than their overweight counterparts (odds ratio, 2.13). Most patients (68.3%) had a pathologic gallbladder on blinded review. However, this did not correlate with outcome.

Conclusions

Most gallbladders removed for biliary dyskinesia are pathologic. Being overweight can be considered a relative contraindication to cholecystectomy for biliary dyskinesia.     

Treatment of levodopa-induced dyskinesia

Levodopa provides the most effective symptomatic treatment for Parkinson's disease (PD). Initiation of treatment of PD too early and/or very aggressive treatment with large doses of levodopa results in severe motor fluctuations and dyskinesias in 30% of patients with PD. Chronic levodopa treatment over a period of 9 years or more will invariably result in disabling motor fluctuations in 90% of PD patients. The motor fluctuations and associated dyskinesia are due to progressive dopamine denervation, an unregulated pattern of release of dopamine in the synapse, fluctuating levels of receptor sensitivity, and fluctuating levels of dopamine receptor stimulation. Once the dyskinesias are established, they are difficult to treat. The current medical therapy is a by-product of several explorative open-label trials, as well as a few blinded and double-label placebo-controlled clinical trials, of varying duration in a small number of patients. These studies suggest that amantadine, a glutamate antagonist, may be the most effective, easily available, and inexpensive medical treatment for levodopa-induced dyskinesia. Several other drugs, already approved for other medical ailments, also have been tried but not evaluated in large-scale clinical trials. None of these drugs is approved by the US Food and Drug Administration specifically for levodopa-induced dyskinesia. By far, the most effective treatment of levodopa-induced dyskinesia appears to be deep brain stimulation, with globus pallidus interna or the subthalamic nucleus as the two major targets of placement of electrodes.     

内源性大麻素的中枢镇痛位点

内源性大麻素(endocannabinoids,EC)在机体具有广泛的生理作用,其中EC通过作用于中枢和外周神经系统的CB1受体可产生镇痛效应.现综述内源性大麻素系统(endocannabinoid system,ECS)的特性在慢性痛和应激性镇痛(stressinduced analgesia,SIA)中的作用,以及支持EC在棘上水平导水管周围灰质(periaqueductal graymatter,PAG)、延脑头端腹内侧区(rostral ventromedial medulla,RVM)和杏仁核镇痛的行为学、神经生理学和神经解剖学证据.     

Neuropsychological disturbances in thalamic hemorrhage--clinical study

Neuropsychological disturbances are frequently associated with hemorrhagic stroke of the thalamus. MATERIAL AND METHOD: We present our personal findings on 117 patients admitted in the Ist Neurological Clinic, la?i with hemorrhagic stroke of the thalamus. RESULTS: Transcortical aphasia for the left-sided strokes and anosognosia or hemi-neglect were among the most prominent clinical features, especially for large thalamic hemorrhage. Visual or tactile extinction, memory disturbances, agitation and hallucinosis were also exhibited in various proportions.     

A comprehensive screen of genes implicated in craniosynostosis

Recent advances in human molecular genetics have identified mutations in the TWIST, FGFR-1, FGFR-2 and FGFR-3 genes to be important causes of craniosynostosis. Despite this, however, mutations cannot be identified in the majority of patients. This study reports the first comprehensive screen of mutations in TWIST, FGFR-1, FGFR-2 and FGFR-3 genes in a cohort of patients with craniosynostosis. This has led to the identification of Saethre-Chotzen syndrome to be a new microdeletion disorder and reports the first example of a gene-environment interaction leading to craniosynostosis. In addition, investigation of the expression patterns of the Fgfr and Twist genes in the normal developing mouse coronal suture has identified the TWIST protein to be important in cranial suture initiation and biogenesis. These findings have significant clinical implications and will form the basis of future attempts to develop novel therapies aimed at inhibiting cranial suture fusion.     

胆囊功能紊乱的临床诊治进展

胆囊功能紊乱（GD）是指有胆道绞痛的典型临床表现,却没有可以用来解释这种临床表现的异常病理生理发现的胆囊疾病。近年来,临床上对该病的诊治正逐步趋向统一,笔者就GD的研究进展做一综述。     

Effects of laparoscopic cholecystectomy in normokinetic biliary dyskinesia

This is the largest single center retrospective study to date looking at response to laparoscopic cholecystectomy in patients with acalculous biliary disease. A chart review was completed on 1116 patients from 2009 to 2014 who had admitting diagnoses related to acalculous cholecystitis and biliary colic. Four hundred and seventy four patients were available for long term follow up (6 months or longer). Multiple factors were studied as related to cholescintigraphy scans with cholecystokinin administration (HIDA with CCK). Hyperkinetic, normokinetic and hypokinetic ejection fractions (EF), as well as reproduction of symptoms with administration of CCK were catagorized. ROME III criteria (Table 1) were used to describe cholecystitis/biliary colic symptoms. (1).It was found that rates of resolution of symptoms after laparoscopic cholecystectomy in normokinetic and hypokinetic were similar. It was also found that reproduction of symptoms after administration of CCK was a better predictor of favorable response to surgery than calculated ejection fraction.     

Bacteriological aspects implicated in abdominal surgical emergencies

The purpose of the present study was to establish the microbial etiology of abdominal surgical emergencies as well as the relationship between the bacterial etiology and the virulence factors produced by the respective isolated strains. 110 bacterial strains were isolated from 100 randomized clinical cases, operated during 2009-2010 in the First Surgical Clinic of the University Hospital of Bucharest. The clinical cases (sex ratio 52 M/48F aged between 22-85 years old) were classified into three risk groups, as related to their severity. The isolated strains were characterized by cultural, microscopic and biochemical methods. After identification, the bacterial strains were investigated for their virulence potential (adherence to abiotic surface and production of soluble virulence factors). RESULTS: The specimens were collected from different clinical pathologies: diffuse acute peritonitis, biliary duct infections, severe acute pancreatitis followed by septic processes etc. The 110 bacterial (72 aerobic and 38 anaerobic) strains were isolated only in 70 out of 100 cases. Out of these 70 cases, in 45 already submitted to pre-operatory empiric broad spectrum antibiotic therapy, there were isolated 74 strains, whereas in 25 cases without any treatment, there were isolated 36 strains. The etiology was either mono-specific or multi-specific (aerobic-anaerobic associations, especially in old persons). Out of the 30 negative culture cases, 16 were already submitted to pre-operatory parenteral empiric antibiotic therapy at the moment of specimen collection. The aerobic etiology was dominated by Enterobacteriaceae. The most frequent anaerobic species belonged to Clostridium, Peptococcus and Bacteroides genera. It is to be mentioned that the isolation of Bifidobacterium and Veillonella spp. in 11 (10%) severe cases of the studied abdominal surgical emergencies is pleading for the fact that in certain conditions, bacteria belonging usually to commensal gut flora can turn to pathogenic becoming responsive for life-threatening cases. All aerobic and anaerobic strains exhibited some of the following virulence factors: mucinase, esculinase, pore-forming toxins (lecithinase), proteolytic enzymes, adherence ability (slime factor). The presence of these virulence factors (VF) could explain the severity of the clinical aspects. CONCLUSIONS: The bacterial etiology of the abdominal surgical emergencies exhibited a very large spectrum, the highest number of strains being of endogenous origin (Enterobacteriaceae and anaerobic strains). It was demonstrated that the isolated strains produced (cell associated and soluble) VF proving in this way their role as important virulence sources in the hospital environment and explaining the large diversity and severity of the clinical abdominal pathology. The results of the present study are also pleading for periodical readjustments of the pre-operatory empiric antibiotic therapy.     

Surgical treatment of thalamic tumors

15 cases of thalamic tumor are presented. Among them, 6 cases were diagnosed by ventriculography and angiography before 1980. Since 1981, 9 cases were diagnosed by CT scan. Operation was refused in 3 cases. Lateral ventriculo and superior sagittal sinus shunt was performed in one case. Open biopsy by craniotomy followed by ventriculo-interhemispheric fissure shunt was done in 2 cases. Partial resection of tumor in 8 cases. Total resection was achieved in one case. The choice of treatment of thalamic tumors is discussed. The author prefers direct operation for that may got some tumor tissues and could made the actual diagnosis pathologically. The quantity of tumor removed is decided according to the situation. Raised intracranial pressure must be controlled by shunt, and preventing its infection is very important.