Citations

The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino‐autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures.

AbstractThe histone deacetylases (HDACs) occur in 11 different isoforms, and these enzymes regulate the activity of a large number of proteins involved in cancer initiation and progression. The discovery of isoform‐selective HDAC inhibitors (HDACIs) is desirable, as it is likely that such compounds would avoid some of the undesirable side effects found with the first‐generation inhibitors. A series of HDACIs previously reported by us were found to display some selectivity for HDAC6 and to induce cell‐cycle arrest and apoptosis in pancreatic cancer cells. In the present work, we show that structural modification of these isoxazole‐based inhibitors leads to high potency and selectivity for HDAC6 over HDAC1–3 and HDAC10, while unexpectedly abolishing their ability to block cell growth. Three inhibitors with lower HDAC6 selectivity inhibit the growth of cell lines BxPC3 and L3.6pl, and they only induce apoptosis in L3.6pl cells. We conclude that HDAC6 inhibition alone is insufficient for disruption of cell growth, and that some degree of class 1 HDAC inhibition is required. Moreover, the highly selective HDAC6Is reported herein that are weakly cytotoxic may find use in cancer immune system reactivation.

AbstractBackgroundSymptoms suggestive of gastroparesis are non‐specific and conflicting reports exist regarding the ability of symptoms to predict the presence of gastroparesis. Our aim, therefore, was to evaluate the relationships between gastroparetic symptoms and their impact on quality of life and determine their relationship with clinical factors and gastric emptying.MethodsGastric emptying scintigraphy, sociodemographic features, health care resource utilization, gastroparetic symptoms, and quality of life using validated questionnaires were obtained from consecutive patients referred for gastric emptying testing (GET). Descriptive analyses were conducted and logistic regression was performed to evaluate associations with abnormal gastric emptying after controlling for other covariates.Key ResultsTwo hundred and sixty‐six patients participated (195 females; mean age, 49.1 ± 17.6 years); 75% met Rome III criteria for functional dyspepsia. Gastric emptying was delayed in 28.2% at 4 h; the delay was mild in 48%, moderate in 20% and severe in 32%. Nausea/emesis and postprandial fullness, but not bloating, were significantly greater in those with delayed emptying. Postprandial fullness was most severe. Weak correlations were identified between symptom severity and the severity of gastric emptying delay. Quality of life was also lower in the delayed emptying group. Logistic regression analysis demonstrated associations between delayed gastric emptying and lower quality of life and increased symptom severity.Conclusions & InferencesIn patients referred for GET, gastroparetic symptoms were more severe in those with delayed emptying. A decrease in quality of life in those with delayed gastric emptying was also present; this was not related to the severity of the delay in gastric emptying.

Aim: Missing data, particularly missing variables, can create serious analytic challenges in observational comparative effectiveness research studies. Statistical linkage of datasets is a potential method for incorporating missing variables. Prior studies have focused upon the bias introduced by imperfect linkage. Methods: This analysis uses a case study of hepatitis C patients to estimate the net effect of statistical linkage on bias, also accounting for the potential reduction in missing variable bias. Results: The results show that statistical linkage can reduce bias while also enabling parameter estimates to be obtained for the formerly missing variables. Conclusion: The usefulness of statistical linkage will vary depending upon the strength of the correlations of the missing variables with the treatment variable, as well as the outcome variable of interest.

Midcervical contusion injuries disrupt descending ipsilateral excitatory bulbospinal projections to phrenic motoneurons, compromising ventilation. We hypothesized that a unilateral contusion injury at C3 versus C5 would differentially impact phrenic activity reflecting more prominent disruption of ipsilateral descending excitatory drive to more caudal segments of the phrenic motor pool with more cranial injuries. Phrenic motoneuron counts and evidence of diaphragm muscle denervation at individual neuromuscular junctions (NMJ) were evaluated at 14 days post-injury after unilateral contusion injury (100 kDynes). Whole body plethysmography and chronic diaphragm EMG were measured before the injury and at 3, 7, and 14 days post-injury. Contusion injuries at either level resulted in a similarly sized cavity. C3 contusion resulted in loss of 39 ± 13% of ipsilateral phrenic motoneurons compared with 13 ± 21% after C5 contusion ( p = 0.003). Cervical contusion injuries resulted in diaphragm muscle denervation (C3 contusion: 17 ± 4%; C5 contusion: 7 ± 4%; p = 0.047). The pattern of denervation revealed segmental innervation of the diaphragm muscle, with greater denervation ventrally after C3 contusion and dorsally after C5 contusion. Overall, diaphragm root mean square electromyography activity did not change ipsilaterally after C3 or C5 contusion, but increased contralaterally (∼11%) after C3 contusion only on the first day post-injury ( p = 0.026). Similarly, there were no significant changes in breathing parameters during eupnea or exposure to hypoxia (10% O 2 ) – hypercapnia (5% CO 2 ) at any time post-injury. Unilateral midcervical contusions minimally impair ventilatory behaviors despite phrenic motoneuron loss and diaphragm muscle denervation.

Objective To survey neurology residency program directors (PDs) on trainee exposure, supervision, and credentialing in procedures widely utilized in headache medicine. Background Clinic‐based procedures have assumed a prominent role in headache therapy. Headache fellows obtain procedural competence, but reliance on fellowship‐trained neurologists cannot match the population eligible for treatments. The inclusion of educational modules and mechanisms for credentialing trainees pursuing procedural competence in residency curricula at individual programs is not known. Methods A web‐based survey of US neurology residency PDs was designed by the American Headache Society (AHS) procedural special interest section in collaboration with AHS and American Academy of Neurology's Headache and Facial Pain section leadership. The survey addressed exposure, training, and credentialing in: (1) onabotulinumtoxinA (onabotA) injections, (2) extracranial peripheral nerve blocks (PNBs), and (3) trigger point injections (TPIs). Results Fifty‐five PDs (42.6%) completed the survey. Compared to noncompleters, survey completers were more likely to feature headache fellowships at their institutions (38.2% vs 10.8%, P =0.0002). High exposure (onabotA=90.9%, PNBs=80.0%, TPIs=70.9%) usually featured hands‐on patient instruction (66.2%) and lectures (55.7%). Supervised performance rates were high (onabotA=65.5%, PNBs=60.0%, TPIs=52.7%), usually in continuity clinic (60.0%) or headache elective (50.9%). Headache specialists (69.1%) or general neurology (32.7%) faculty most commonly trained residents. Formal credentialing was uncommon (16.4‐18.2%), mostly by documenting supervised procedures (25.5%). Only 27.3% of programs permitted trainees to perform procedures independently. Most PDs felt procedural exposure (80.0‐90.9%) and competence (50.9‐56.4%) by all trainees was important. Conclusions Resident exposure to procedures for headache is high, but credentialing mechanisms, while desired by most PDs, are not generally in place. Implementation of a credentialing process may ensure trainees enter practice with the ability to perform procedures safely and effectively.