Cavernous Nerve Injury by Radiation Therapy May Potentiate Erectile Dysfunction in Rats.

PURPOSE/OBJECTIVES: Radiation-induced erectile-dysfunction (RiED) is one of the most common side effects of radiation therapy (RT) and significantly reduces the quality of life (QoL) of cancer patients. Approximately 50% of prostate cancer patients experience RiED within 3 to 5 years after completion of RT. A series of vascular, muscular, and neurogenic injuries after prostate RT lead to RiED; however, the precise role of RT-induced neurogenic injury in RiED has not been fully established. The cavernous nerves (CN) are postganglionic parasympathetic nerves located beside the prostate gland that assist in penile erection. This study was designed to investigate the role of CN injury, tissue damage, and altered signaling pathways in an RiED rat model. METHODS AND MATERIALS: Male rats were exposed to a single dose of 25 Gy prostate-confined RT. Erectile function was evaluated by intracavernous pressure (ICP) measurements conducted both 9 and 14 weeks after RT. Neuronal injury was evaluated in the CN using quantitative polymerase chain reaction, conduction studies, transmission electron microscopy, and immunoblotting. Masson trichrome staining was performed to elucidate fibrosis level in penile tissues. RESULTS: There were significant alterations in the ICP (P<.0001) of RT rats versus non-RT rats. TEM analysis showed decreased myelination, increased microvascular damage, and progressive axonal atrophy of the CN fibers after RT. Electrophysiologic analysis showed significant impairment of the CN conduction velocity after RT. RT also significantly increased RhoA/Rho-associated protein kinase 1 (ROCK1) mRNA and protein expression. In addition, penile tissue showed increased apoptosis and fibrosis 14 weeks after RT. CONCLUSIONS: RT-induced CN injury may contribute to RiED; this is therefore a rationale for developing novel therapeutic strategies to mitigate CN and tissue damage. Moreover, further investigation of the RhoA/ROCK pathway's role in mitigating RiED is necessary.

Incidence of pre- and postoperative urinary dysfunction associated with deep infiltrating endometriosis: relevance of urodynamic tests and therapeutic implications.

Although many series have been published on the management of digestive or urinary deep infiltrating endometriosis (DIE), few data exist on pre- and postoperative urinary dysfunction (UD) and urodynamic tests. Hence, the objective of this review was to evaluate the pre- and postoperative incidence of UD and the contribution of urodynamic tests as well as their therapeutic implications. Studies published between January 1995 and April 2012, available in the databases Medline, Embase or the Cochrane Library and responding to a key word algorithm were selected. Studies were classified according to their level of evidence in the Canadian Task Force classification. Sixty-three studies were included in this review. The incidence of preoperative UD is unknown in patients with DIE without colorectal involvement but ranges from 2% to 48% in patients with colorectal endometriosis. About half of all the patients had abnormal urodynamic test results. DIE surgery is associated with a risk of urinary dysfunction mainly corresponding to de novo voiding dysfunction in 1.4% to 29.2% of cases with a mean value of 4.8%. The rate of persistent voiding dysfunction ranges from 0 to 14.7% with a mean value of 4.6%. Risk factors of postoperative UD are the need for partial colpectomy, parametrectomy and patients requiring colo-anal anastomosis. For patients with urinary tract endometriosis, the incidence of preoperative UD is comprised between 24.4% and 79.2% with a rate of postoperative voiding dysfunction ranging from 0% to 16.9% with a mean value of 11.1%. Prevention of postoperative UD is based on nerve-sparing surgery. Treatment of voiding dysfunction requires self-catheterization. There is a lack of data on medical treatment and surgical techniques to manage postoperative UD. More effort needs to be made to detect preoperative UD associated with DIE. Preoperative evaluation by urodynamic tests and possibly electrophysiology could be of interest especially in patients with risk factors. The current review underlines the difficulties of establishing clear recommendations due to heterogeneity of the studies and the absence of a consensual definition of UD.

The nervus intermedius: a review of its anatomy, function, pathology, and role in neurosurgery.

BACKGROUND: Geniculate neuralgia, although uncommon, can be a debilitating pathology. Unfortunately, a thorough review of this pain syndrome and the clinical anatomy, function, and pathology of its most commonly associated nerve, the nervus intermedius, is lacking in the literature. Therefore, the present study aimed to further elucidate the diagnosis of this pain syndrome and its surgical treatment based on a review of the literature. METHODS: Using standard search engines, the literature was evaluated for germane reports regarding the nervus intermedius and associated pathology. A summary of this body of literature is presented. RESULTS: Since 1968, only approximately 50 peer-reviewed reports have been published regarding the nervus intermedius. Most of these are single-case reports and in reference to geniculate neuralgia. No report was a review of the literature. CONCLUSIONS: Neuralgia involving the nervus intermedius is uncommon, but when present, can be life altering. Microvascular decompression may be effective as a treatment. Along its cisternal course, the nerve may be difficult to distinguish from the facial nerve. Based on case reports and small series, long-term pain control can be seen after nerve sectioning or microvascular decompression, but no prospective studies exist. Such studies are now necessary to shed light on the efficacy of surgical treatment of nervus intermedius neuralgia.

Remodeling of the guinea pig intrinsic cardiac plexus with chronic pressure overload.

Chronic pressure overload (PO) is associated with cardiac hypertrophy and altered autonomic control of cardiac function, in which the latter may involve adaptations in central and/or peripheral cardiac neural control mechanisms. To evaluate the specific remodeling of the intrinsic cardiac nervous system following pressure overload, the descending thoracic aorta artery of the guinea pig was constricted approximately 20%, and the animals recovered for 9 wk. Thereafter, atrial neurons of the intrinsic cardiac plexus were isolated for electrophysiological and immunohistochemical analyses. Intracellular voltage recordings from intrinsic cardiac neurons demonstrated no significant changes in passive membrane properties or action potential depolarization compared with age-matched controls and sham-operated animals, but afterhyperpolarization duration was increased in PO animals. Neuronal excitability, as determined by the number of action potentials produced with depolarizing stimuli, was differentially increased in phasic neurons derived from PO animals in response to exogenously applied histamine compared with sham and age-matched controls. Conversely, pituitary adenylate cyclase-activating polypeptide-induced increases in intrinsic cardiac neuron evoked AP frequency were similar between control and PO animals. Immunohistochemical analysis demonstrated a twofold increase in the percentage of neurons immunoreactive for neuronal nitric oxide synthase in PO animals compared with control. The density of mast cells within the intrinsic cardiac plexus from PO animals was also increased twofold compared with preparations from control animals. These results indicate that congestive heart failure associated with chronic pressure overload induces a differential remodeling of intrinsic cardiac neurons and upregulation of neuronal responsiveness to specific neuromodulators.

Mydriatic pupil in giant cell arteritis.

A mydriatic pupil has been infrequently reported as a manifestation of giant cell arteritis. We report a patient with acute, evolving pupil dilation who was diagnosed with biopsy-proven giant cell arteritis. We document the time course for the development of pupillary near-light dissociation and denervation hypersensitivity. We discuss the possible mechanisms leading to mydriasis, including 1) parasympathetic dysfunction due to ischemia of the ciliary ganglion and post-ganglionic parasympathetic fibers and 2) direct iris ischemia. Repeated episodes of pupil dilation in this patient suggested ongoing microvascular insufficiency.

Arachnoid cyst causing third cranial nerve palsy manifesting as isolated internal ophthalmoplegia and iris cholinergic supersensitivity.

An 8-month-old boy presented with anisocoria, a sluggishly reactive right pupil, and cholinergic supersensitivity as the only signs of what proved months later to be compressive third cranial nerve palsy due to an arachnoid cyst. Tonic constriction and dilation, segmental iris sphincter palsy, aberrant regeneration phenomena, ductional deficits, and ptosis were absent. The initial diagnosis was postganglionic internal ophthalmoplegia attributed to a viral ciliary ganglionopathy. Nineteen months later, he had developed an incomitant exodeviation and a supraduction deficit. Brain MRI revealed a mass consistent with an arachnoid cyst compressing the third cranial nerve in the right interpeduncular cistern. Resection of the cyst led to a persistent complete third cranial nerve palsy. This is the second reported case of prolonged internal ophthalmoplegia in a young child as a manifestation of a compressive third cranial nerve palsy. Our patient serves as a reminder that isolated internal ophthalmoplegia with cholinergic supersensitivity is compatible with a preganglionic compressive third nerve lesion, particularly in a young child.

Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis.

In this study, we used a well-established animal model to investigate changes in the peptidergic and parasympathetic innervation of the bladder following chronic bladder inflammation. Adult female Sprague-Dawley rats were injected with either 70 mg/kg cyclophosphamide diluted in saline, i.p., once every 3 days or saline. After 10 days, all animals were tested for urinary frequency and number of low volume voids, as well as symptoms of spontaneous pain. At the end of 12 days, all animals were perfused with histological fixatives and the urinary bladders processed for immunofluorescence using antibodies against calcitonin gene-related peptide and the vesicular acetylcholine transporter as markers, respectively, of peptidergic primary afferent fibers and parasympathetic efferent fibers. We show that animals treated with cyclophosphamide had inflamed bladders and displayed high urinary frequency as well as some indicators of spontaneous pain, such as piloerection and a rounded-back posture. Furthermore, they had a significant increase in the density of both parasympathetic and peptidergic sensory fibers in the bladder mucosa and an increase in peptidergic sensory fibers in the detrusor muscle. Based on these results, we suggest that peripheral sprouting of parasympathetic and peptidergic fibers could be a mechanism responsible for sensitization of the bladder, leading to urinary symptoms. Since we observed that the parasympathetic and peptidergic fibers often wrapped around one another and that their varicosities were very close, these two fiber populations may be interacting with each other to lead to and maintain sensitization. Future studies are required to establish the role of this fiber sprouting in bladder symptoms.

Role of spinal nitric oxide synthase-dependent processes in the initiation of the micturition hyperreflexia associated with cyclophosphamide-induced cystitis.

The aim of this study was to examine the participation of nitrergic neurotransmission in the initiation of micturition hyperreflexia associated to cyclophosphamide (CP)-induced cystitis in rats. Micturition threshold volume was significantly reduced 4 h after CP administration (100 mg/kg, i.p.); this reduction was attenuated by intra-arterially injected N(G)-nitro-l-arginine-methyl ester (l-NAME), a non selective nitric oxide synthase (NOS) inhibitor, but not by intravesical infusion of S-methyl-l-thiocitrulline (l-SMTC), another structurally different NOS inhibitor. Interestingly, l-NAME failed to affect micturition threshold volume in normal rats. The magnitude of isolated detrusor strips contractions elicited by either carbachol or nerve activation was significantly reduced in CP-treated rats but was unaffected by the addition of N(G)-nitro-l-arginine (l-NOARG), a nonselective NOS inhibitor. In contrast, intrathecal l-NAME and l-SMTC but not N(G)-nitro-d-arginine-methyl ester (d-NAME) administration augmented the micturition threshold volume in CP-treated rats in an l-arginine preventable manner. As with the systemic injection, intrathecal l-NAME also did not affect the micturition threshold volume in normal rats. Four hours after CP injection, the number of neuronal NOS immunoreactive or nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) positive neurons in spinal lumbosacral segments (L6-S2) was not altered whereas the number of c-Fos immunoreactive neurons increased significantly in the dorsal gray commissural nucleus (DGC), the parasympathetic sacral nucleus (PSN) and lamina X of these segments. Ca(2+)-dependent, but not Ca(2+)-independent NOS activity increased significantly in spinal L6-S2 segments but not in thoracic segments of CP-treated rats. These data indicate that the micturition hyperreflexia observed in the initial hours of CP-induced cystitis is associated with an increase in Ca(2+)-dependent NOS activity in spinal L6-S2 segments suggesting an increased production of nitric oxide (NO). The increased production of NO in these spinal segments appears to be necessary for the initiation of the micturition hyperreflexia.

Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy?

The cardinal ligament (CL) of the uterus is present as a specific part of the parametrium when the pararectal and paravesical spaces are developed surgically. According to usual nerve-sparing radical hysterectomy (the Tokyo method), the CL is divided into two parts, the vascular part for dissection and the nerve part that contains the pelvic splanchnic nerve (PSN) as a major target for nerve sparing. In contrast, we hypothesized that the CL and another structure outside of the usual area for surgical dissection, that is, the lateral rectal ligament, are mutually continuous and that the PSN runs through the lateral ligament rather than the CL. In the present study, a combination of routine dissection, fresh cadaver dissection and in situ sectional anatomy revealed that: (i) the CL did not contain the PSN; (ii) a well-defined fascial structure existed in the bottom or dorsal margin of the CL area; and (iii) the pelvic plexus was separated from vascular components of the CL. The present results provide a new perspective for nerve-sparing radical hysterectomy with extensive lateral parametrial dissection of the CL.

Nitric oxide synthase I and VIP-activated signaling are affected in salivary glands of NOD mice.

The autoimmune sialadenitis developed by non-obese diabetic (NOD) mice is considered a suitable model to study the ethiopathogenic mechanisms leading to sicca symptoms in Sjögren's syndrome (SS). Evidence supporting a neural rather than immune origin of the secretory dysfunction has been provided. As both nitric oxide and vasoactive intestinal peptide (VIP) are common messengers to nervous and immune systems mediating secretory and inflammatory responses, we examined nitric oxide synthase (NOS) activity with special focus on VIP-mediated effects in salivary glands of NOD mice. We found a decreased NOS activity and expression in major salivary glands of NOD mice with respect to control mice. In addition, there was a deficient VIP-activated signaling associated with a reduced saliva and amylase secretion in response to VIP. Our results support the hypothesis of an impaired balance of neuroimmune interactions in salivary glands as early events to take place in the progressive loss of secretory function of NOD mice.

Gustatory sweating: clinical implications and etiologic aspects.

PURPOSE: It was the aim of this study to provide detailed general information on the clinical picture of different kinds of gustatory sweating, including reevaluation of a series of patients who underwent parotidectomy, removal of the submandibular gland, or neck dissection. PATIENTS AND METHODS: This study summarizes the statements of 548 patients questioned about the occurrence of gustatory sweating after parotidectomy (n = 296), extirpation of the submandibular gland (n = 79), and neck dissection (n = 173). RESULTS: After parotidectomy, 45% of the patients had noticed gustatory sweating. In most of them (70%), the symptoms began within 6 months after surgery. Gustatory sweating developed in only one patient with submandibular extirpation (1.5%), and not at all after neck dissection. Most patients (52%) reported that the symptoms occurred independent of the kind of food ingested. These results show that the "masticatory component" is an important trigger for Frey's syndrome. Application of Minor's test localized gustatory sweating mainly in the region of previous parotid lobe removal, but also in other areas deriving their sensory supply from the auriculotemporal, greater auricular, and lesser occipital nerves. The size of the area affected by the sweating was similar after lateral and total parotidectomy. When evaluating clinical symptoms, subjective assessment by the patients seemed to play a major role. After submandibular extirpation and neck dissection, some patients reported gustatory sweating that was not verified by Minor's test. CONCLUSION: There is general agreement that the cause of gustatory sweating is sympathetic or parasympathetic innervation of previously denervated sweat glands, initiated by gustatory triggers. The location of the "erroneous innervation" depends on the type of lesion. In cases after parotidectomy, misdirected parasympathetic regeneration is the model integrating all known factors into a rational concept. For didactic and systematic-pragmatic reasons, a clinically oriented classification of gustatory sweating (types I to III) seems to be useful.

Oligotide, a new single-stranded oligodeoxyribonucleotide, preserves postsynaptic beta-adrenergic and cholinergic receptor functions in rabbit hearts after acute infarction.

Acute myocardial infarction was induced in New Zealand male albino rabbits. 3 days after surgery, the mortality rate and plasma CPK activity were reduced by 64% and 66% respectively by intravenous infusion of Oligotide (32 mg/kg/h for 6h), a single-stranded oligodeoxyribonucleotide of mammalian origin. Perfused hearts, obtained from Oligotide-treated rabbits 3 days after surgery, showed a strength of contraction in the range of that of hearts of sham-operated animals and an ameliorated postsynaptic beta-adrenergic and cholinergic receptor function. In addition, in these hearts, "ex vivo" treatment with Oligotide resulted in almost complete preservation of both adrenergic and cholinergic responses to their specific agonists. These data suggest that Oligotide by protecting the hearts from the ischemic damage and possibly by restricting left ventricular tissue necrosis may have normalized the biological responses of this organ to isoproterenol and preserved the integrity of coronary endothelial-dependent relaxant function.