Modulation of the bulbocavernosus reflex during voiding: loss of inhibition in upper motor neuron lesions

The bulbocavernosus reflex (BCR) is a sacral segmental reflex which is suppressed throughout most of micturition. The BCR was evaluated by recording the associated EMG activity using a concentric needle electrode placed in the external urethral sphincter. The influence of the central nervous system (CNS) on the BCR was studied in 29 neurologically normal individuals and in 33 patients with upper motor neuron (UMN) lesions and voiding dysfunction. Ninety percent (26/29) of the neurologically normal patients did not have a BCR during most of micturition. By comparison, all the patients with an UMN lesion had a positive BCR beginning early during voiding. The finding of suprasegmental modulation of the BCR during voiding demonstrated by external urethral sphincter EMG was a more sensitive although slightly less specific sign of UMN bladder dysfunction than detrusor sphincter dyssynergia; uninhibited bladder contractions were neither sensitive nor specific for UMN lesions.     

Electrophysiological analysis of pudendal neuropathy following traction

Pudendal neuropathy is an unusual but important complication of orthopedic surgical procedures involving traction on the fracture table. We describe the clinical and electrophysiological features in six patients presenting with perineal sensory disorders and sexual dysfunction following surgical repair of femoral fracture, hip dislocation, or intra-articular foreign body, in which the traction table was used. All underwent electrophysiological recordings: bulbocavernosus muscle electromyography (EMG), measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), sensory conduction velocity of the dorsal nerve of the penis (SCVDNP), and pudendal nerve terminal motor latencies (PNTMLs). Signs of denervation localized to the territory of the pudendal nerve were found in 3 patients, normal BCRL in 6, abnormal SEPPNs in 4, and abnormal SCVDNPs and PNTMLs in all cases. The outcome at 2-year follow-up was good, except in one patient with initially unrecordable PNTML. Perineal electrophysiological examination can thus confirm the pudendal neuropathy and give prognostic information.     

EMG, single fibre EMG and sacral reflexes in assessment of sacral nervous system lesions.

EMG of pelvic floor muscles, single fibre EMG of external anal sphincter and both bulbocavernosus and anal reflexes were investigated in 31 men without sacral nervous system lesions and in 12 patients with neurogenic erectile impotence, of whom one had slight loss of sensitivity to pinprick in the lower sacral dermatomes. EMG and single fibre EMG abnormalities have been found concomitantly in eight patients and six of these had also prolonged bulbocavernosus reflex latencies. In two patients the prolonged bulbocavernosus reflex latency was the only abnormality. Single fibre EMG of anal sphincter muscle seems to be superfluous in routine evaluation of sacral nervous system lesions.     

Lower urinary tract dysfunction in Machado-Joseph disease: a study of 11 clinical-urodynamic observations

OBJECTIVES: Machado-Joseph disease (MJD), or hereditary spinocerebellar ataxia type 3, is the most common dominantly inherited ataxia. However, lower urinary tract (LUT) dysfunction in MJD has not been fully delineated. We investigated LUT dysfunction in MJD by clinical-urodynamic observations. METHODS: In 24 genetically diagnosed MJD, we recruited all 11 patients with LUT symptoms (six men, five women; age, 18-61 [mean 48] years; disease duration, 2-24 [mean 9] years; voiding difficulty, 7, urinary incontinence, 4). Urodynamic studies consisted of uroflowmetry, measurement of post-void residuals and electromyography (EMG)-cystometry. Neurophysiology tests consisted of motor unit potential (MUP) analysis of the sphincter and extremity muscles, tibial nerve somatosensory evoked potentials (SEP) and nerve conduction studies (NCS) of the extremities. RESULTS: Urodynamic abnormalities were seen in all 11 patients studied. Maximum or average flow rate was decreased in five. Post-void residual was noted in three but residual urine volume > 100 ml was noted in only one patient. Maximum urethral closure pressure was low in one and high in one of five patients studied. EMG-cystometry during filling showed detrusor overactivity in five, impaired bladder sensation in four, low compliance detrusor in one, uninhibited sphincter relaxation in one and incompetent urethra in one. Voiding phase abnormalities included detrusor areflexia in three and detrusor-sphincter dyssynergia in two. Bethanechol supersensitivity of the bladder was noted in one of three patients studied. Bulbocavernosus reflex was absent in two of five patients studied. MUP analysis showed neurogenic changes in six of nine sphincter muscles and in all six extremity muscles studied. Five patients had prolonged or absent cortical response in SEP and four had sensory axonal neuropathy in NCS, which were relevant to the impaired bladder sensation. CONCLUSION: In the present study, a half of MJD patients had LUT symptoms and they showed various urodynamic abnormalities. Detrusor overactivity, impaired bladder sensation, and neurogenic sphincter EMG were common findings, and large post-void residuals were rare. These findings are relevant to central and peripheral nervous system pathology of MJD.     

The Holmes-Adie plus syndrome

A clinical syndrome of tonic pupil associated with tendon areflexia was first described by Holmes and Adie; autonomic neuropathy and peripheral neuropathy can be associated. The postulated mechanism of areflexia in Holmes-Adie syndrome is a synaptic disorder of the spinal reflex pathways. We report a case of a Holmes-Adie syndrome variant with hitherto unreported cranial neuropathy. A 41 year old woman developed insidious onset of sensory symptoms related to her left trigeminal and chorda tympani nerves over a few months. Physical examination showed generalised tendon areflexia and a left sided Adie’s pupil. Imaging did not reveal any structural abnormality. Electrophysiological studies demonstrated an absent blink reflex on stimulating the left supraorbital and infraorbital nerves. These findings were suggestive of a dysfunction affecting the brain stem reflex arc. The pathophysiological process of Holmes-Adie syndrome may be more widespread than previously thought.     

肌电图对糖尿病周围神经病的诊断价值

目的：探讨神经肌电图在糖尿病性周围神经病（DPN ）诊断中的应用价值。方法：选择我院2012年1月～2014年6月收治的200例DPN患者的临床资料,分析肌电诱发电位仪对患者的相关神经进行检测的结果。结果：在200例DPN患者中,神经电图总异常率高达71．5％。且随着病程的延长,其EM G异常率的发生逐渐增加。病程在1年以内的患者EM G异常率为40．8％,而病程在10年以上者异常率达到92．2％。病程在1年以内的患者H反射异常率为46．9％,而病程在10年以上者H反射异常率达到94％。其次是腓总神经运动传导速度（MCV）、腓浅神经感觉传导速度（SCV）异常率,分别是43．1％和58．8％,均超过40％。EM G结果提示：病程＜1年组拇短展肌、肱二头肌、胫前肌、趾总伸肌EM G异常率均为0,病程≥10年组异常率分别为17．6％、9．8％、21．5％、31．4％,同样随病程延长而异常率增加。结论：EM G在诊断DPN中具有较高的准确性,有利于早期发现和进行治疗。     

Postpartum lumbosacral plexopathy limited to autonomic and perineal manifestations: clinical and electrophysiological study of 19 patients

The objective was to describe perineal electrophysiological findings and to determine their diagnostic value in a type of lumbosacral plexopathy after vaginal delivery, which only involves the lower part of the plexus (S2-S4). Consecutive female patients referred to an outpatients' urodynamic clinic were the source. Nineteen previously healthy women, 13 multiparae and six para 1, were investigated. Mean age was 33.7 (SD 5.4) (range 28-41) years. All of them presented with urinary (stress incontinence 14, dysuria five), anorectal (faecal incontinence eight, dyskesia one), or sexual dysfunctions (hypoorgasmia or anorgasmia six) after vaginal delivery. No associated lower limb sensory or motor deficits were noted. All the patients had electrophysiological recordings (bulbocavernosus muscle EMG, measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), and pudendal nerve terminal motor latencies (PNTMLs)). Cystometry and urethral pressure profile (UPP) were performed in the 14 patients with stress urinary incontinence. Perineal electrophysiological examination disclosed signs of denervation in the perineal muscles in all the cases, prolonged BCRLs in 17/19, and abolished BCRLs in 2/19, abnormal SEPPN in 1/19, and normal PNTMLs in all the patients. Urodynamic investigations disclosed low urethral closure pressure for age (< 50 cm H(2)O) in half of the patients. In conclusion, Lower postpartum lumbosacral plexopathy is evoked when perineal sensory disturbances whether or not associated with urinary or faecal incontinence persist after a history of a difficult vaginal delivery. Electrophysiological investigations precisely identify the site of the lesion and demonstrate distal innervation integrity.     

Damage to the innervation of the voluntary anal and periurethral sphincter musculature in incontinence: an electrophysiological study.

In 40 women with idiopathic (neurogenic) faecal incontinence, 20 of whom also had stress urinary incontinence, single fibre EMG studies showed an increased fibre density in the external anal sphincter muscle. All these patients showed excessive descent of the pelvic floor on straining. The mean terminal motor latencies in the pudendal and perineal nerves, measured by a digitally-directed intrarectal stimulating technique, were increased when compared with 20 control subjects (p less than 0.01). The perineal nerve terminal motor latency was more markedly increased in the 20 patients with double incontinence than in those with faecal incontinence alone (p less than 0.01). These results provide direct electrophysiological evidence of damage to the innervation of the pelvic floor musculature in idiopathic faecal and double incontinence, and imply that idiopathic stress urinary incontinence may have a similar cause.     

Clinical, urodynamic and neurophysiological findings in patients with neuropathic bladder due to a lumbar intervertebral disc protrusion

Sacral nerve roots are affected in 1 to 15% of reported cases of lumbar disc protrusions (mainly posterior) (Scott, 1965). Urinary retention is the commonest symptom. In the last 6 years, we have observed 22 patients (18 males and 4 females) with a neuropathic bladder due to this condition in the acute phase. They underwent intermittent catheterisation (IC), and manoeuvres such as Credé and Valsalva's at fixed times. Almost all obtained a balanced bladder. (Follow-up: 24 months.) The most common urodynamic finding at the onset was bladder areflexia with severe denervation of the perineal floor. At follow-up, 65% still had bladder areflexia and 29% normoreflexia, all with normal compliance. Perineal floor innervation showed a fair recovery, mainly in the efferent part. An hypothesis is presented to explain why this kind of neuropathic bladder has a normal compliance.     

Components of the neural circuitry of the vaginocavernosus reflex in rabbits

In mammals the mechanisms underlying female sexual and reproductive biology are poorly understood. Little attention has been paid to striated muscles and their neural regulation. The aim of the present study was to describe the components of the vaginocavernosus reflex in adult rabbits. It was found that mechanical stimulation of the glans of the clitoris and the perineal vagina induced electromyographic (EMG) responses in bulbocavernosus (Bcm) and ischiocavernosus (Icm) muscles. Unilateral and bilateral nerve transection indicated that the clitoral nerve is the main afferent path of the reflex and that it recruits ipsilateral and contralateral perineal motoneurons. Injection of horseradish peroxides‐wheat germ agglutinin (HRP‐WGA) into the Bcm and Icm labeled spinal motoneurons scattered in L7 and S1 segments. According to the results of this study and previous work, the elements of the vaginocavernosus reflex may be described as follows. Mechanical receptors are located in the glans clitoris and in the wall of the perineal vagina. The main afferent pathway is the clitoral nerve. It activates ipsilateral and contralateral Bcm and Icm motoneurons in lumbosacral segments. Axons of efferent neurons travel through the clitoral and ischiocavernosus nerves, and the effectors are the Bcm and Icm perineal muscles. Identification of neural components of the vaginocavernosus reflex in rabbits will allow the use of this animal as a model to assess the physiological characteristics of the perineal motoneurons as well as the contribution of the Bcm and Icm in female urogenital functions. J. Comp. Neurol. 518:199–210, 2010. © 2009 Wiley‐Liss, Inc.     

Urinary frequency in a case of Neuro-Behcet disease involving the brainstem - clinical, electrophysiological and urodynamic features

Micturitional disturbances are reported in 5-20% of patients with Behcet disease (BD) affecting the central nervous system. However, corresponding data regarding urodynamic and electrophysiological findings are limited. A patient with known BD presented with dysarthria, diplopia and urinary frequency (36 times/day). MRI revealed an extensive lesion involving the lateral and tegmental pons, reaching the pontomedullary junction. Auditory evoked potentials indicated a left-side lesion between superior olivary nucleus and superior colliculus. Blink reflex examination indicated a location caudal to the left trigeminal root. Pudendal nerve somatosensory evoked potentials and transcranial magnetic stimulation of the perineal muscles were slightly affected. Bulbocavernosus reflex latencies were normal. EMG of the bulbocavernosus muscles showed a normal maximal voluntary contraction activity. Urodynamic studies revealed normal urine volume, maximum flow rate and residual volume. After intravenous administration of methylprednisolone diplopia and dysarthria resolved within 3 weeks. Urinary frequency remained almost unchanged for the first 8 weeks, but clearly improved during the following months. We assume that the present case of urinary frequency is the result of vasculitic lesion affecting the pontine micturition inhibitory area on the ground of Neuro-Behcet disease.     

Micturitional disturbance in subacute myelo-optico-neuropathy (SMON)

BACKGROUND: Micturitional disturbance is known to occur in subacute myelo-optico-neuropathy (SMON). However, its pathophysiology is uncertain and few data are available concerning urodynamic findings. We described our results of micturitional histories and urodynamic studies in patients with SMON. METHODS: A history of urinary symptoms was obtained from six patients with SMON (two men, four women; age, 49-72 years, mean 60 years; duration of illness, 14-25 years, mean 19 years). All patients underwent urodynamic studies including measurement of post-micturition residuals, urethral pressure profilometry, cystometry and simultaneous sphincter electromyography. RESULTS: All patients had micturitional symptoms including voiding symptoms in four, filling symptoms in four and urge urinary incontinence in a patient. Urodynamic studies revealed an increased maximum urethral closure pressure in two of four patients studied, decreased bladder volume at first sensation in two, detrusor hyperreflexia in three, absent bulbocavernosus reflex in a patient, and none had detrusor-sphincter dyssynergia or post-micturition residuals. Repeated urodynamic study (10 years after initial study) in a patient with detrusor hyperreflexia showed the same findings. CONCLUSION: Our results indicate that supranuclear pelvic nerve dysfunction to be mainly responsible for the micturitional disturbance in patients with SMON.     

Bladder dysfunction in subacute combined degeneration

Objective   In view of the paucity of studies on micturition disturbance in subacute combined degeneration (SACD), this prospective study reports micturition disturbance in SACD and correlations with urodynamic and MRI findings. Methods   SACD was diagnosed by clinical features and low serum B12 level (< 211 pg/ml) and/or megaloblastic bone marrow. Micturition disturbances were categorized into voiding and storage symptoms and scored using the American Urological Association Symptoms (AUAS) score. Spinal MRI and urodynamic studies were carried out. Patients were treated with vitamin B12 1000 μg daily i.m. and outcome was defined at 6 months into complete, partial and poor. Results   Eight patients with SACD aged 53.8 (44–70) years were included; 2 of whom were females. The mean duration of illness was 2.2 (1–120) months. All had walking difficulty, 2 were wheelchair bound and 4 bedridden. Lower limb spasticity and joint position impairment were present in all; ankle reflex was absent and pinprick sensation reduced distally in 4 patients each. T2 hyperintensity in the posterior spinal cord was present in 5 and in subcortical white matter in 2 patients. Five patients had storage, 7 voiding and 4 had both dysfunctions. AUAS score was 14.63 (4–35). On urodynamic study, detrusor areflexia was present in 2, neurogenic detrusor overactivity with high pressure voiding in 3 and normal in 2 patients. The urinary symptoms improved in all (AUAS score 3.67). Repeat urodynamic study in 2 patients, who had detrusor areflexia improved. At 6 mo, 3 patients had complete, 4 partial and 1 poor recovery. Conclusion   Bladder symptoms occur in advanced cases of SACD; both de trusor areflexia and neurogenic detrusor overactivity with high pressure voiding occur and respond to B12 therapy.     

癌性Lambert-Eaton肌无力综合征四例临床及电生理研究

目的研究癌性Lambert－Eaton肌无力综合征（LEMS）临床及电生理特征。方法回顾性地评价了4例病理证实的癌性LEMS（例1、2为小细胞性肺癌，例3为肾上腺癌，例4为乳腺癌）的临床和电生理资料。结果面神经、腋神经及尺神经重复电刺激示，诱发电位起始波幅减小（0．4～0．7mV）；5Hz以下低频刺激后波幅递减16％～54％（对照：小于15％），但在10Hz以上高频刺激后波幅递增120％～657％（对照：小于65％）；例2和例3肌电图和神经传导速度测定示，多发周围神经源性损害，以感觉神经纤维轴索损害为主。结论观察结果表明，部分癌性LEMS患者的神经肌肉接头和周围神经可同时受累。     

Urodynamic and neurophysiological evaluation in Parkinson's disease and multiple system atrophy.

AIMS: To determine whether Parkinson's disease and multiple system atrophy each has a distinct pattern of micturition abnormalities and whether a urodynamic evaluation could be useful in the differential diagnosis between the two diseases. METHODS: Sixty two patients (30 with Parkinson's disease and 32 with multiple system atrophy) underwent a complete urodynamic evaluation and neurophysiological testing. RESULTS: Of the parkinsonian patients 36.6% had normal micturition findings with normal bladder sensitivity; 26.7% had delayed or incomplete pelvic floor relaxation; 26.7% had hyperreflexia with vesicosphincteric synergy; and 10% had hyperreflexia with vesicosphincteric synergy associated with incomplete pelvic floor relaxation. Parkinsonian patients with a normal urodynamic pattern had significantly less severe disease and a shorter duration of disease in years than those who had abnormal patterns. Patients with hyperreflexia had significantly higher severity of disease. All the patients with multiple system atrophy had hyperreflexia with synergy. Two urodynamic patterns were identified: hyperreflexia with vesicosphincteric synergy (90.6% of patients), and hyperreflexia with vesicosphincteric synergy and incomplete pelvic floor relaxation (in 9.4%). Hyperreflexia with synergy correlated neither with the severity nor with the duration of disease. Sphincter EMG analysis showed that all the parkinsonian patients had normal sphincter EMG whereas 24 of the 32 patients with multiple system atrophy had neurogenic signs. CONCLUSIONS: Urodynamic evaluation and sphincter EMG are both useful tests in the differential diagnosis between Parkinson's disease and multiple system atrophy. Urodynamic findings may be abnormal before patients with multiple system atrophy reach an advanced stage of the disease. Recordings of EMGs from perineal muscles become abnormal as the disease progresses in multiple system atrophy but not in Parkinson's disease.     

Micturitional disturbance in neuro-Behçet's syndrome

BACKGROUND: Micturitional disturbance is known to occur in neuro-Beh?et's syndrome (NBS). However, its pathophysiology is uncertain and few data are available concerning urodynamic findings. We describe our findings on micturitional histories and urodynamic studies in patients with NBS. METHODS: A history of urinary symptoms was obtained from nine patients with NBS [seven male, two female, aged 26 to 54 years; mean, 41 years]. Neurological and CT/MRI findings indicated that their lesions were located mainly in the cerebral cortex, basal ganglia, cerebellum, brainstem and the spinal cord. Symptomatic patients underwent urodynamic studies, including measurement of post-micturition residuals, urethral pressure profilometry and EMG cystometry. RESULTS: Six of the nine patients (67%) had urinary symptoms that included diurnal urinary frequency in five, sensation of urgency in five, urge urinary incontinence in five, voiding difficulty in five and nocturnal urinary frequency in four. None had urinary retention. Urodynamic studies performed in six patients showed post-micturition residuals in five (50-180 ml), increased maximum urethral closure pressure in two, decrease in four and increase in one of bladder capacities, detrusor hyperreflexia in five, decreased bladder sensation in one, brisk bulbocavernosus reflex in four, detrusor-sphincter dyssynergia in two and neurogenic sphincter EMG in one. CONCLUSION: Our results indicate that micturitional disturbance is not rare in patients with NBS. Supranuclear pelvic nerve dysfunction seems to be mainly responsible for the disturbance.     

Clinical and electrophysiological appraisal of the significance of radicular injury in back pain.

Clinical electrophysiological studies were analysed in 60 consecutive patients with back pain with or without other evidence for a radiculopathy. These studies included needle EMG of relevant limb and paraspinal muscles as well as F responses and H reflexes recorded from the soleus muscle. Segmental denervation was found in 29 of the 60 patients. In 57 patients, abnormal slowing of the F response was present in 27, either unilaterally (25) or bilaterally (two). In 18 of 47 patients with H reflex studies, the H reflex was either unilaterally absent (12), asymmetrically prolonged (five), or bilaterally prolonged (one). Statistically significant (P less than 0.05) associations were found between (1) abnormalities of H reflexes and F responses, (2) F response slowing and radicular injury shown by EMG, (3) segmentally consistent radiographic defects and abnormalities of both H reflexes and F responses, and (4) depressed Achilles reflexes as well as sensory loss and abnormal H reflexes. No significant association, however, was present between abnormalities of EMG, F responses, or H reflexes and pain radiation by history or positive straight leg-raising tests. These data suggest that pain in radicular syndromes is related to the functioning of smaller afferent fibres.     

Direct and reflex responses in perineal muscles on electrical stimulation.

Responses in the external anal and urethral sphincters as well as in the bulbocavernosus muscle have been evoked by supramaximal electrical stimulation of the penis (or clitoris), perineum and the peri-anal region and recorded electromyographically in 82 male subjects 5 to 73 years old and in nine female subjects 18 to 55 years old, who had no systemic diseases or demonstrable sacral nervous system lesion. On perineal stimulation (including the penis or clitoris) reflex responses with a typical latency of 33 ms and which exhibit no habituation were obtained in all muscles examined. Stimulation of the peri-anal region gave habituating reflex responses with a typical latency of 55 ms in all muscles examined. On perineal, and sometimes also peri-anal stimulation, stable short latency responses with typical latencies of 5 and 13 ms were recorded; both were considered to be direct responses. The different evoked muscle responses obtained by stimulation in the perineal and peri-anal region have to be distinguished when the bulbocavernosus and anal reflexes are recorded for evaluation of sacral nervous system lesions.     

Positive salivary gland biopsy, Sjögren syndrome, and neuropathy: clinical implications

The relationship between neuropathy and Sj?gren syndrome has been predicated largely on sicca symptoms or serological abnormalities rather than salivary gland pathology. We reviewed consecutive neuropathy patients who had had a lip biopsy to identify features of the neuropathy that were associated with a positive lip biopsy suggesting Sj?gren syndrome. Twenty of 54 neuropathy patients were biopsy positive; 13 had a painful or nonspecific sensory neuropathy and only 4 were ataxic. Sicca symptoms were not associated with a positive biopsy (P = 0.14). Serological abnormalities were found more often in the biopsy-positive group (P = 0.008), but anti-Sj?gren syndrome A or B (anti-SSA or SSB) antibodies were detected in only 30%. There were no other clinical or electromyographic (EMG) features associated with a positive biopsy. From this experience, we conclude that: (1). most patients with neuropathy and a positive lip biopsy for Sj?gren syndrome have a painful, distal, sensory axonal neuropathy; (2). there are no clinical or EMG features that are predictive of a positive lip biopsy; (3). ataxic neuropathy is uncommon; and (4). the lack of sicca symptoms or anti-SSA or SSB antibodies in patients with neuropathy does not exclude Sj?gren syndrome based upon salivary gland pathology.     

Electrophysiological evaluation of genito-sphincteric dysfunction in multiple system atrophy

Thirteen patients with multiple system atrophy underwent multimodality neurophysiological evaluation, including sphincteric needle electromyography (EMG), sacral reflexes, pudendal nerve terminal latency, pudendal (PSEPs) and tibialis posterior nerve somatosensory evoked potentials (TPSEPs), and perineal motor evoked potentials (PMEPs). EMG revealed denervation or neurogenic changes, with reduction in spontaneous tonic activity at rest and abnormal pudendal nerve terminal latency in 10 patients (76.9%); anal reflex was delayed in 7 patients (53.8%). TPSEPs scalp responses were clearly abnormal in 4 patients (30.7%), whereas PSEPs exhibited changes in 9 (69.2%): in 6 patients responses were delayed at lumbar level (46.2%), and in 5 over the scalp (38.4%). PMEPs showed an increase in latency with a mild prolongation of central motor conduction time (CMCT) in 2 cases (15.3%); 1 patient had prolonged latencies following both cortical and sacral stimulation, but a normal CMCT. Even if diagnostic yield is not improved using these investigations they provide evidence of multiple lesion sites other than Onuf's nucleus.