Rectal hyposensitivity: evaluation of anal sensation in female patients with refractory constipation with and without faecal incontinence.

Rectal hyposensitivity (RH) is commonly found in patients with intractable constipation, faecal incontinence or both. Anal sensation may also be blunted in these conditions. We aimed to determine whether RH is associated with anal hyposensitivity, which may reflect a combined viscero-somatic neuropathy. One hundred and fifty-eight female patients with chronic constipation underwent physiological investigation including rectal sensation to volumetric balloon distension, and distal anal mucosal sensation to electrostimulation. Data were also obtained from 32 healthy female volunteers. Anal mucosal electrosensory thresholds were significantly higher in patients compared with volunteers (median: 2.4 mA, range: 0.4-19.6 vs 1.1 mA, range: 0.1-4.2, respectively), although the patient group was older (P < 0.0001), but there was no difference (P = 0.572) in the incidence of blunted anal sensation between those with normal rectal sensation (n = 113, 20% abnormal) and RH (n = 45, 24% abnormal). Irrespective of rectal sensory function, there was a strong association between symptom duration (P = 0.012) and anal hyposensitivity. One-fifth of constipated female patients had evidence of diminished anal sensation. However, the presence of RH was not associated with an increased frequency of anal hyposensitivity, thereby suggesting that different aetiopathogenic mechanisms underlie the development of anal and rectal hyposensitivity. Further studies in carefully selected, homogenous patient populations are necessary to elucidate these mechanisms.     

Sympathetic (electrodermal) activity during repeated maximal rectal distensions in patients with irritable bowel syndrome and constipation

Abstract  Irritable bowel syndrome (IBS) is associated with visceral hypersensitivity, stress and autonomic dysfunction. Sympathetic activity during repeated events indicates excitatory or inhibitory mechanisms such as sensitization or habituation. We investigated skin conductance (SC) during repetitive rectal distensions at maximal tolerable pressure in patients with IBS and chronic constipation. Twenty-seven IBS patients, 13 constipation patients and 18 controls underwent two sets of isobaric rectal distensions. First, maximal tolerable distension was determined and then it was repeated five times. Skin conductance was measured continuously. Subjective symptom assessment remained steady in all groups. The baseline values of SC were higher in IBS patients than in patients with constipation and significantly lower in constipation patients than in controls. The maximal SC response to repetitive maximal distensions was higher in IBS patients compared with constipation patients. The amplitude of the initial SC response decreased successively with increased number of distensions in patients with IBS and constipation but not in controls. Irritable bowel syndrome and constipation patients habituated to maximal repetitive rectal distensions with decreasing sympathetic activity. Irritable bowel syndrome patients had higher sympathetic reactivity and baseline activity than constipation patients. A lower basal SC in constipation patients compared with controls suggests an inhibition of the sympathetic drive in constipation patients.     

Movement-related cortical potentials in patients with cerebellar degeneration

We studied the topographic distribution of scalp-recorded, averaged movement-related cortical potentials occurring immediately before and after the onset of voluntary movements in six patients with cerebellar degenerative disease. We placed 26 electrodes on the scalp overlying the sensorimotor area and recorded cortical potentials related to abduction of the index finger. The amplitudes and latencies of the potentials were normal in all patients except two, in whom the negative slope (NS') was absent. All patients had an abnormal topographic pattern of potentials compared with normal subjects. The initial slope of motor potential (isMP), which was focal and contralateral in the normal subjects, was diffuse and bilateral in the patients. The topography of the frontal peak of motor potential (fpMP) was more posterior in the patients than in normal subjects. The patterns found in this preliminary study indicate a derangement of sensorimotor cortex activity in voluntary movement as a consequence of cerebellar dysfunction.     

Brain function in patients with cerebral fat embolism evaluated using somatosensory and brain-stem auditory evoked potentials

Summary In two victims of traffic accidents with broken bones and fat embolism, serial recordings of somatosensory evoked potentials (SEPs) and brain-stem auditory evoked potentials (BAEPs) were examined to assess brain function. Initial SEPs and BAEPs revealed normal subcortical components, while the late cortical components of SEPs were abolished, findings indicative of diffuse dysfunction of grey rather than of white matter. As the neurological functions became normal, the late components appeared. It is concluded that while absent late components of SEPs do reflect cortical dysfunction, they are not necessarily associated with a poor prognosis. Repetitive recordings of SEPs appear to be a useful tool for assessing the neurological condition and the prognosis of patients with cerebral fat embolism.     

Rectal hyposensitivity is uncommon and unlikely to be the central cause of obstructed defecation in patients with high‐grade internal rectal prolapse

Background There are several causes of obstructed defecation one of which is thought to be internal rectal prolapse. Operations directed at internal prolapse, such as laparoscopic ventral rectopexy, may improve obstructed defecation symptoms significantly. It is not clear whether the obstructed defecation with internal prolapse is a mechanical phenomenon or whether it results changes in rectal sensitivity. This study aimed to evaluate rectal sensory function in patients with obstructed defecation and high‐grade internal rectal prolapse. Methods This study represents a retrospective review of a prospectively collected database of patients attending a tertiary referral pelvic floor unit. Patients with high‐grade (recto‐anal) intussusception formed the basis of this study. Rectal sensory function was determined by intrarectal balloon inflation. Three parameters (sensory threshold, urge to defecate and maximum tolerated volumes) were recorded. Abnormal sensitivity was defined as partial (one or two parameters abnormal) or total (all three abnormal). Key Results Four hundred and eight patients with high‐grade internal rectal prolapse both with and without obstructed defecation symptoms were studied. Two hundred and forty one (59%) had normal sensation. Eighteen (4%) had total hyposensitivity and three (1%) total hypersensitivity. A further 96 (24%) had partial hyposensitivity whilst 50 (12%) had partial hypersensitivity. Neither hypersensitivity nor hyposensitivity differed between patients with and without symptoms of obstructed defecation. Conclusions & Inferences Rectal hyposensitivity is relatively uncommon in patients with high‐grade internal rectal prolapse and obstructed defecation. Internal rectal prolapse may cause obstructed defecation through a mechanical process. It does not appear that rectal hyposensitivity plays a significant part in the pathological process.     

大脑语言运动区手术中的神经电生理监测(附52例分析)

目的研究大脑语言运动区病变手术中神经电生理监测的方法。方法对52例病变位于语言运动区的病人采用术中唤醒全麻，联合监测皮质体感诱发电位、直接皮质电刺激、肌电图及脑电图，同时行显微手术切除病变。结果全切除42例，次全切除10例。术中记录到典型的皮质体感诱发电位38例，其中波形倒置23例，最大波幅者20例。皮质电刺激与体感诱发电位所判定的中央前回位置完全相符者33例．皮质体感诱发电位不典型者电刺激阳性5例。肌电图变化与肌肉运动相符者20例，肌电图出现反应波而未见肌肉运动者10例。脑电图示癫痫波20例，广泛性慢波40例。术后症状改善或消失47例。结论语言运动区病变采用术中唤醒全麻，联合监测皮质体感诱发电位、直接皮质电刺激、肌电图与脑电图等神经电生理指标，有助于在最大限度保留脑功能的前提下全切除病变．保证手术安全．明显减少术后功能障碍的发生。     

Rectal sensorimotor characteristics in female patients with idiopathic constipation with or without paradoxical sphincter contraction

Patients with chronic constipation fulfilling the Thompson criteria can show paradoxical sphincter contraction. Aim of this study was to evaluate rectal sensorimotor characteristics in patients with constipation with or without paradoxical sphincter contraction. Thirty female patients with chronic constipation and 22 female controls were investigated with anal manometry and rectal barostat. Paradoxical sphincter contraction was shown with manometry as a paradoxical increase of anal pressure during straining. Visceral sensitivity and compliance were tested by intermittent and continuous pressure-controlled distension. Patients were classified according to their sensations and compliance into normal, hypersensitive, reduced compliant, insensitive or excessive compliant rectum. Postprandial rectal response (PRR) and phasic volume events (PVEs) were registered for 1 h after a 600-kCal meal. Paradoxical sphincter contraction was found in 13 (43%) patients. In these patients, rectal sensitivity scores were higher (P = 0.045) than in patients without paradoxical contractions, but rectal compliance was not different. In 90% of patients an abnormal rectal sensitivity or compliance was found: excessively compliant in 35%, reduced compliant in 10%, hypersensitive in 27% and hyposensitive in 17%. Both patients with constipation (11%; P = 0.042) and controls (25%; P = 0.002) exhibited the presence of a postprandial rectal response. This response was not significantly different between idiopathic constipation, paradoxical sphincter contraction and controls. Patients with rectal hypersensitivity had lower response than other patients (P = 0.04). Patients with constipation had fewer basal PVEs compared controls (P = 0.03). Postprandial PVEs increased in both patients (P = 0.014) and controls (P < 0.001). Postprandial rectal response and PVE were not different in patients with or without paradoxical sphincter contraction. A total of 90% of female patients with idiopathic constipation show an abnormality in rectal sensation or compliance. The postprandial rectal response was comparable between patients with constipation and controls, however, PVEs were diminished. Patients with paradoxical sphincter contraction had higher rectal sensitivity but an unaltered compliance and postprandial rectal response. Future trials should investigate whether the classification of rectal abnormalities in patients with constipation has clinical importance.     

Aberrant functional brain network dynamics in patients with functional constipation

The aberrant static functional connectivity of brain network has been widely investigated in patients with functional constipation (FCon). However, the dynamics of brain functional connectivity in FCon patients remained unknown. This study aimed to detect the brain dynamics of functional connectivity states and network topological organizations of FCon patients and investigate the correlations of the aberrant brain dynamics with symptom severity. Eighty‐three FCon patients and 80 healthy subjects (HS) were included in data analysis. The spatial group independent component analysis, sliding‐window approach, k‐means clustering, and graph‐theoretic analysis were applied to investigate the dynamic temporal properties and coupling patterns of functional connectivity states, as well as the time‐variation of network topological organizations in FCon patients. Four reoccurring functional connectivity states were identified in k‐means clustering analysis. Compared to HS, FCon patients manifested the lower occurrence rate and mean dwell time in the state with a complex connection between default mode network and cognitive control network, as well as the aberrant anterior insula–cortical coupling patterns in this state, which were significantly correlated with the symptom severity. The graph‐theoretic analysis demonstrated that FCon patients had higher sample entropy at the nodal efficiency of anterior insula than HS. The current findings provided dynamic perspectives for understanding the brain connectome of FCon and laid the foundation for the potential treatment of FCon based on brain connectomics.     

情感性障碍患者脑诱发电位变异与自杀行为的相关性研究

目的探讨情感性障碍患者脑诱发电位(BEP)变异与自杀行为的关系。方法应用国产脑诱发电位仪,记录了41例抑郁症、24例躁狂发作患者和33名正常对照者的3种脑诱发电位。结果与正常对照组相比,抑郁症和躁狂发作组均出现脑诱发电位主成分波幅降低,抑郁症VEP/P2潜伏期延迟[正常对照组(194±19)m s,抑郁症自杀史阳性组(212±22)m s,抑郁症自杀史阴性组(209±17)m s,P<0.01]。两组患者的BEP改变主要与患者有无自杀行为史有关。结论脑诱发电位临床价值得到了初步证实,与自杀行为相关的生物学指标研究中需进一步追踪随访。     

脑干听觉诱发电位及体感诱发电位在重型颅脑损伤患者预后评估中的作用

目的 分析探讨脑干听觉诱发电位(BAEP)及体感诱发电位(SEP)与重型颅脑损伤病人预后的关系.方法 对33 例重型颅脑损伤患者早期行BAEP 及SEP 测定并进行动态监测,同时行头颅CT 检查并记录GCS 评分.结果 BAEP 及SEP 预测预后的敏感性、特异性、准确性均较高.BAEP、SEP 异常程度低,则预后较好;异常程度高,则预后不良.结论 BAEP、SEP 可以比较准确地评估重型颅脑损伤患者的预后.     

Evaluation of afferent pain pathways in adrenomyeloneuropathic patients

Objective

Patients with adrenomyeloneuropathy may have dysfunctions of visual, auditory, motor and somatosensory pathways. We thought on examining the nociceptive pathways by means of laser evoked potentials (LEPs), to obtain additional information on the pathophysiology of this condition.

体感诱发电位对重型颅脑创伤患者预后预测作用的Meta分析

目的 分析体感诱发电位对重型颅脑创伤患者预后的评估作用.方法 将1980,1月～2012,4月发表在MEDLINE,EMBASE,OVID,Cochrane libraries数据库中相关的英文文献进行汇总和Meta分析,并将体感诱发电位对预后的评估价值与格拉斯哥昏迷评分(GCS评分)做比较.结果 检索共发现10篇文献符合入选标准并纳入meta分析,其中6篇进行了与GCS评分比较.体感诱发电位预测良好预后的灵敏度为0.69(95％ CI,0.63～0.74)、特异度0.73(95％CI,0.68-0.78)、阳性似然比2.71 (95％ CI,1.77～4.15);对不良预后的预测灵敏度为0.58(95％ CI,0.50 ～0.66),特异度0.82(95％CI,0.77 ～0.86),阳性似然比3.61(95％ CI,2.38-5.47).分析发现体感诱发电位在预测患者预后时特异度高于GCS评分,其中对不良预后预测的灵敏度与GCS相当,但对良好预后预测的灵敏度不如GCS.结论 体感诱发电位对重型颅脑创伤患者预后有良好的预测价值.     

Characterization of cortical potentials evoked by oesophageal balloon distention and acid perfusion in patients with functional heartburn

Oesophageal visceral hypersensitivity is thought to be important in generating symptoms in functional heartburn (FH). However, the neurophysiological mechanisms involved are poorly understood. The aim of this study was to compare the characteristics of oesophageal cortical evoked potentials (CEPs) induced by balloon distension and acid perfusion in FH and controls. We studied 21 FH patients and 12 healthy volunteers. Oesophageal mechanical stimulation was performed using the specially constructed mechanical pump. CEPs were recorded using the 10-20 international system of electroencephalogram recording. Oesophageal distention elicited recognizable, reproducible and muti-peak CEPs. CEP latencies for N1, P1 and N2 components were significantly shorter (P = 0.016, P = 0.003 and P = 0.031, respectively) in FH than in controls before perfusion. Acid perfusion significantly decreased the latencies of N1, P1 and N2 (P = 0.022, P = 0.007 and P = 0.041, respectively) and significantly increased the amplitude of P1-N2 components (P = 0.020) in FH patients, but not in controls. In conclusion, cortical evoked potential responses evoked by oesophageal distention and acid perfusion were greater in FH than in controls, suggesting that dysfunction of visceral neural pathways and/or alterations in cortical processing may produce and mediate oesophageal hypersensitivity in FH. These findings provide the evidence that central sensitization contributes to the development and maintenance of oesophageal hypersensitivity.