Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Histomorphometric results of different grafting materials and effect of healing time on bone maturation after sinus floor augmentation: a systematic review and meta-analysis.

The aim of this systematic review was to evaluate histomorphometric variables, the amount of new bone (NB), residual graft (RG) particles and soft tissue (ST), related to various grafting materials and assess the effect of graft healing time on different histomorphometric outcomes. Studies that were published before October 2015 were electronically and manually searched in three databases. We included human studies that reported the amount of NB, RG and ST in the biopsies taken from the grafted sinuses. Based on the applied grafting materials, extracted data were categorized into different groups. Furthermore, extracted data were classified into three groups based on healing time: (i) ≤ 4.5 mo; (ii) 4.5-9 mo; and (iii) ≥ 9-13.5 mo. The search provided 791 titles. Full text analysis was performed for 258 articles resulting in 136 studies that met the inclusion criteria. Autogenous bone (AB) resulted in the highest amount of NB and lowest amount of RG compared to other grafting materials. Based on this meta-analysis, a significant difference was noticed in the amount of NB formation in grafts with a healing time of > 4.5 mo when compared to the grafts with less healing time. However, when comparing biopsies taken at 4.5-9 mo of healing (average = 6.22 mo) to the ones taken at ≥ 9-13.5 mo (average = 10.36 mo), no significant difference was noticed in the amount of NB formation of various grafts except allografts that resulted in a significantly higher percentage of NB at 9.5 mo of healing. Based on histomorphometric analysis, AB results in the highest amount of NB formation in comparison to the other grafting materials. Bone substitute materials (allografts, alloplastic materials and xenografts) seem to be good alternatives to autogenous bone and can be considered as grafting materials to avoid disadvantages related to AB, including morbidity rate, limited availability and high volumetric change. Combining AB with alloplastic materials and xenografts brings no significant advantages regarding NB formation.

Depressive symptoms account for differences between self-reported versus polysomnographic assessment of sleep quality in women with myofascial TMD.

Patients with temporomandibular disorder (TMD) report poor sleep quality on the Pittsburgh Sleep Quality Index (PSQI). However, polysomnographic (PSG) studies show meagre evidence of sleep disturbance on standard physiological measures. The present aim was to analyse self-reported sleep quality in TMD as a function of myofascial pain, PSG parameters and depressive symptomatology. PSQI scores from 124 women with myofascial TMD and 46 matched controls were hierarchically regressed onto TMD presence, ratings of pain intensity and pain-related disability, in-laboratory PSG variables and depressive symptoms (Symptoms Checklist-90). Relative to controls, TMD cases had higher PSQI scores, representing poorer subjective sleep and more depressive symptoms (both P < 0·001). Higher PSQI scores were strongly predicted by more depressive symptoms (P < 0·001, R2 = 26%). Of 19 PSG variables, two had modest contributions to higher PSQI scores: longer rapid eye movement latency in TMD cases (P = 0·01, R2 = 3%) and more awakenings in all participants (P = 0·03, R2 = 2%). After accounting for these factors, TMD presence and pain ratings were not significantly related to PSQI scores. These results show that reported poor sleep quality in TMD is better explained by depressive symptoms than by PSG-assessed sleep disturbances or myofascial pain. As TMD cases lacked typical PSG features of clinical depression, the results suggest a negative cognitive bias in TMD and caution against interpreting self-report sleep measures as accurate indicators of PSG sleep disturbance. Future investigations should take account of depressive symptomatology when interpreting reports of poor sleep.

Validity of self-reported sleep bruxism among myofascial temporomandibular disorder patients and controls.

Sleep bruxism (SB), primarily involving rhythmic grinding of the teeth during sleep, has been advanced as a causal or maintenance factor for a variety of oro-facial problems, including temporomandibular disorders (TMD). As laboratory polysomnographic (PSG) assessment is extremely expensive and time-consuming, most research testing this belief has relied on patient self-report of SB. The current case-control study examined the accuracy of those self-reports relative to laboratory-based PSG assessment of SB in a large sample of women suffering from chronic myofascial TMD (n = 124) and a demographically matched control group without TMD (n = 46). A clinical research coordinator administered a structured questionnaire to assess self-reported SB. Participants then spent two consecutive nights in a sleep laboratory. Audiovisual and electromyographic data from the second night were scored to assess whether participants met criteria for the presence of 2 or more (2+) rhythmic masticatory muscle activity episodes accompanied by grinding sounds, moderate SB, or severe SB, using previously validated research scoring standards. Contingency tables were constructed to assess positive and negative predictive values, sensitivity and specificity, and 95% confidence intervals surrounding the point estimates. Results showed that self-report significantly predicted 2+ grinding sounds during sleep for TMD cases. However, self-reported SB failed to significantly predict the presence or absence of either moderate or severe SB as assessed by PSG, for both cases and controls. These data show that self-report of tooth grinding awareness is highly unlikely to be a valid indicator of true SB. Studies relying on self-report to assess SB must be viewed with extreme caution.

Oxidative burst intensity of peripheral phagocytic cells and periodontitis in Down syndrome.

BACKGROUND: This study investigated the oxidative burst function of peripheral phagocytic cells (granulocytes and monocytes) and assessed the relation between oxidative burst and periodontal status in adult individuals with Down syndrome (DS) vs. other groups. METHODS: Of 55 DS individuals (18-56 years old), 74 individuals with mental retardation (MR) and 88 medically healthy controls (HC) participated in the study. The MR and HC groups were age, race and gender matched with the DS group. Gingival index, plaque index, probing depth, attachment level and bleeding on probing were recorded for each subject. Whole blood was collected for granulocyte/monocyte oxidative burst tests. Oxidative burst was determined by flow cytometry in terms of percentage of cells actively involved in oxidative burst, and oxidative intensity (magnitude of ROIs per cell). RESULTS: The basal oxidative burst intensity of DS granulocytes was higher than that of HC and MR granulocytes (p = 0.05). The Escherichia coli stimulated oxidative burst intensity of DS monocytes was higher than that of HC and MR monocytes (p = 0.05). Regression analysis controlling for age, sex, race and plaque levels showed a significant association between monocyte oxidative burst intensity and loss of periodontal attachment in DS subjects (p < 0.01). Regression analysis also showed a significant association between granulocyte oxidative burst intensity and bleeding on probing in all subjects (p < 0.05). CONCLUSIONS: Oxidative burst activity of peripheral monocytes and granulocytes is elevated in DS affected individuals and may contribute to periodontal tissue inflammation and loss of periodontal attachment in this susceptible group.

Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study.

Patients with temporomandibular muscle and joint disorder (TMJD) increasingly seek and receive treatment for their pain with botulinum toxin (BoNTA; botulinum toxin A). Used intramuscularly in therapeutic doses, it produces localised paresis. Such paresis creates risk of reduced bone mineral density, or 'disuse osteopenia'. Animal studies have frequently used BoNTA as a model of paralysis to induce bone changes within short periods. Osteopenic effects can be enduring in animals but have yet to be studied in humans. This is the first study in humans to examine bone-related consequences of BoNTA injections in the masticatory muscles, comparing oral and maxillofacial radiologists' ratings of trabecular bone patterns in the condyles of patients with TMJD exposed to multiple masticatory muscle injection sessions with BoNTA to a sample of patients with TMJD unexposed to masticatory muscle injections with BoNTA. Cone-beam computed tomography (CBCT)-derived images of bilateral condyles were evaluated in seven patients with TMJD receiving 2+ recent BoNTA treatment sessions for facial pain and nine demographically matched patients with TMJD not receiving BoNTA treatment. Two oral and maxillofacial radiologists evaluated CBCT images for evidence of trabecular changes consistent with osteopenia. Both evaluators noted decreased density in all participants exposed to BoNTA and in none of the unexposed participants (P < 0.001). No other abnormalities associated with reduced loading were detected. These findings need replication in a larger sample and over a longer time period, to ensure safety of patients with TMJD receiving multiple BoNTA injections for their pain.

Masticatory muscle sleep background electromyographic activity is elevated in myofascial temporomandibular disorder patients.

Despite theoretical speculation and strong clinical belief, recent research using laboratory polysomnographic (PSG) recording has provided new evidence that frequency of sleep bruxism (SB) masseter muscle events, including grinding or clenching of the teeth during sleep, is not increased for women with chronic myofascial temporomandibular disorder (TMD). The current case-control study compares a large sample of women suffering from chronic myofascial TMD (n = 124) with a demographically matched control group without TMD (n = 46) on sleep background electromyography (EMG) during a laboratory PSG study. Background EMG activity was measured as EMG root mean square (RMS) from the right masseter muscle after lights out. Sleep background EMG activity was defined as EMG RMS remaining after activity attributable to SB, other orofacial activity, other oromotor activity and movement artefacts were removed. Results indicated that median background EMG during these non-SB event periods was significantly higher (P < 0·01) for women with myofascial TMD (median = 3·31 µV and mean = 4·98 µV) than for control women (median = 2·83 µV and mean = 3·88 µV) with median activity in 72% of cases exceeding control activity. Moreover, for TMD cases, background EMG was positively associated and SB event-related EMG was negatively associated with pain intensity ratings (0-10 numerical scale) on post-sleep waking. These data provide the foundation for a new focus on small, but persistent, elevations in sleep EMG activity over the course of the night as a mechanism of pain induction or maintenance.

Subgingival microbiota in adult Down syndrome periodontitis.

BACKGROUND AND OBJECTIVE: The subgingival microbiota in Down syndrome and non-Down syndrome adults receiving periodic dental care was examined for 40 bacterial species using checkerboard DNA-DNA hybridization and the results were related to clinical periodontal attachment loss. MATERIAL AND METHODS: A total of 44 Down syndrome, 66 non-Down syndrome mentally retarded and 83 mentally normal adults were clinically evaluated. This involved, for each subject, the removal of subgingival specimens from three interproximal sites on different teeth; all subgingival samples per subject were then pooled and assessed for the presence and levels of 40 bacterial species using species-specific whole-genomic DNA probes and checkerboard DNA-DNA hybridization. Significant group differences in species proportions averaged across subjects were evaluated using the Kruskal-Wallis test, and associations between subgingival species and mean subject attachment loss within Down syndrome and non-Down syndrome subject groups were quantified using Pearson correlation and multiple linear regression analysis. RESULTS: Down syndrome subjects exhibited greater attachment loss than non-Down syndrome subjects (p=0.05). Most microbial species were present in Down syndrome subjects at levels similar to non-Down syndrome subjects, except for higher proportions of Selenomonas noxia, Propionibacterium acnes, Streptococcus gordonii, Streptococcus mitis and Streptococcus oralis in Down syndrome subjects compared with non-Down syndrome study subjects, higher proportions of Treponema socranskii in Down syndrome subjects compared with non-Down syndrome mentally retarded subjects, and higher proportions of Streptococcus constellatus in Down syndrome subjects compared with mentally normal subjects. Down syndrome adults classified with periodontitis revealed higher subgingival levels of T. socranskii than Down syndrome subjects with no periodontitis (p=0.02). Higher subgingival proportions of S. constellatus, Fusobacterium nucleatum ssp. nucleatum, S. noxia and Prevotella nigrescens showed significant positive correlations (r=0.35-0.42) and higher proportions of Actinomyces naeslundii II and Actinomyces odontolyticus showed negative correlations (r=-0.36 to -0.40), with increasing mean subject attachment loss in Down syndrome adults. CONCLUSION: Individuals with Down syndrome show higher levels of some subgingival bacterial species and specific associations between certain subgingival bacterial species and loss of periodontal attachment. These findings are consistent with the notion that certain subgingival bacteria may contribute to the increased level of periodontal disease seen in Down syndrome individuals and raise the question as to the reason for increased colonization in Down syndrome.

Phagocytic cell activity and periodontitis in Down syndrome.

BACKGROUND: This study investigated the phagocytic function of peripheral granulocytes and monocytes from adult individuals with Down syndrome (DS) and assessed the relation between phagocytic function and periodontal status. METHODS: Fifty-five DS individuals (18-56 years old), 74 mentally retarded individuals, and 88 medically healthy controls (HC) participated in the study. Gingival inflammation index, plaque index, probing depth, periodontal attachment level (AL), and bleeding on probing were taken for each subject. Whole blood was collected for granulocyte/monocyte phagocytosis tests. Phagocytic function was determined by flow cytometry in terms of percentage of cells actively involved in phagocytosis, and phagocytic intensity (magnitude of the bacterial staining per cell). RESULTS: Phagocytic intensity of both granulocytes and monocytes was comparable in HC and DS subjects. While AL was directly related to phagocytic intensity of both granulocytes (r = 0.14, P = 0.03) and monocytes (r = 0.2, P = 0.003) in all subjects, this relationship was stronger in DS than in other subjects, even after controlling for known risk factors for periodontitis (P < 0.05). Monocyte phagocytic intensity was the only necessary predictor of AL (P = 0.003), indicating a similar relationship between AL and phagocytic activity in either cell type. CONCLUSIONS: While granulocyte and monocyte phagocytic intensities are similar in Down and non-DS individuals, phagocytic intensity was associated with more AL in DS than non-DS individuals.

The Histopathology of Oral Cancer Pain in a Mouse Model and a Human Cohort.

Oral cancer patients often have severe, chronic, and mechanically induced pain at the site of the primary cancer. Oral cancer pain is initiated and maintained in the cancer microenvironment and attributed to release of mediators that sensitize primary sensory nerves. This study was designed to investigate the histopathology associated with painful oral cancers in a preclinical model. The relationship of pain scores with pathologic variables was also investigated in a cohort of 72 oral cancer patients. Wild-type mice were exposed to the carcinogen, 4-nitroquinoline 1-oxide (4NQO). Nociceptive (pain) behavior was measured with the dolognawmeter, an operant device and assay for measuring functional and mechanical allodynia. Lesions developed on the tongues and esophagi of the 4NQO-treated animals and included hyperkeratoses, papillomas, dysplasias, and cancers. Papillomas included lesions with benign and dysplastic pathological features. Two histologic subtypes of squamous cell carcinomas (SCCs) were identified-SCCs with exophytic and invasive components associated with papillary lesions (pSCCs) and invasive SCCs without exophytic histology (iSCCs). Only the pSCC subtype of tongue cancer was associated with nociceptive behavior. Increased tumor size was associated with greater nociceptive behavior in the mouse model and more pain experienced by oral cancer patients. In addition, depth of invasion was associated with patient-reported pain. The pSCC histology identifies 4NQO-induced tongue cancers that are expected to be enriched for expression and release of nociceptive mediators.

Nuclear F-actin Cytology in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma.

Oral cavity cancer has a low 5-y survival rate, but outcomes improve when the disease is detected early. Cytology is a less invasive method to assess oral potentially malignant disorders relative to the gold-standard scalpel biopsy and histopathology. In this report, we aimed to determine the utility of cytological signatures, including nuclear F-actin cell phenotypes, for classifying the entire spectrum of oral epithelial dysplasia and oral squamous cell carcinoma. We enrolled subjects with oral potentially malignant disorders, subjects with previously diagnosed malignant lesions, and healthy volunteers without lesions and obtained brush cytology specimens and matched scalpel biopsies from 486 subjects. Histopathological assessment of the scalpel biopsy specimens classified lesions into 6 categories. Brush cytology specimens were analyzed by machine learning classifiers trained to identify relevant cytological features. Multimodal diagnostic models were developed using cytology results, lesion characteristics, and risk factors. Squamous cells with nuclear F-actin staining were associated with early disease (i.e., lower proportions in benign lesions than in more severe lesions), whereas small round parabasal-like cells and leukocytes were associated with late disease (i.e., higher proportions in severe dysplasia and carcinoma than in less severe lesions). Lesions with the impression of oral lichen planus were unlikely to be either dysplastic or malignant. Cytological features substantially improved upon lesion appearance and risk factors in predicting squamous cell carcinoma. Diagnostic models accurately discriminated early and late disease with AUCs (95% CI) of 0.82 (0.77 to 0.87) and 0.93 (0.88 to 0.97), respectively. The cytological features identified here have the potential to improve screening and surveillance of the entire spectrum of oral potentially malignant disorders in multiple care settings.

Prevalence of myofascial temporomandibular disorder in US community women.

This study estimates the prevalence of the myofascial subtype of temporomandibular disorders (M-TMD) defined by Research Diagnostic Criteria (RDC), and relates that prevalence to the surveyed report of facial pain. From among 20 000 women selected at random in the NY metropolitan area who completed a telephone survey of facial pain, 2000 were invited for an RDC/TMD examination; 782 examinations were completed. Prevalence was estimated in analyses that were weighted to correct sampling biases. Differences among demographic strata were evaluated with logistic regression. The prevalence of M-TMD was estimated to be 10.5% (95% CL = 8.5-13.0%). Prevalence was significantly higher among younger women, among women of lower socio-economic status, among Black women, and among non-Hispanic women. The report of facial pain in the telephone survey (10.1%) had high specificity for M-TMD diagnosis (94.7%), but low sensitivity (42.7%). M-TMD is a fairly common disorder among American women. Among those reporting facial pain during the last month, half met RDC palpation criteria for M-TMD; thus, a formal physical examination is imperative to establish this diagnosis. Prevalence varies with age, socio-economic status, race and Hispanic ethnicity. A substantial number of RDC-diagnosed cases of M-TMD did not report facial pain in the survey; the reason for this requires further study.

Effect of Sonic Resin Composite Delivery on Void Formation Assessed by Micro-computed Tomography.

OBJECTIVES: The aim of this study was to quantify the internal void volume formation in commercially available, resin composites inserted using conventional or sonic insertion methods, and analyzed using three-dimensional (3D) micro-computed tomography (µCT). METHODS AND MATERIALS: Four resin composites were evaluated: one conventional (Herculite, Ultra, Kerr Corporation, Orange, CA, USA), one flowable bulk fill (SureFil SDR Flow, Dentsply International, York, PA, USA), and two packable bulk fill (SonicFill, Kerr Corporation, and Tetric EvoCeram Bulk Fill, Ivoclar Vivadent Inc, Schaan, Liechtenstein). Eight groups were evaluated according to each resin composite type and insertion method (conventional or sonic; n=5). Forty ABS 3D-printed cylindrical molds, 5.0 mm in diameter and 4.0 mm in depth, were fabricated. For the conventional resin composite, the mold was filled incrementally (two layers), while for bulk-fill resin composites, insertion was performed in a single increment. The sonic insertion method was performed using a specific handpiece (SonicFill Handpiece, Kerr Corporation). Resin composites were light cured using a multipeak light-emitting diode light-curing unit (VALO, Ultradent Products Inc, South Jordan, UT, USA) in its regular mode. Samples were evaluated by µCT, and data were imported into software (Amira, version 5.5.2, VSG, Burlington, MA, USA) for 3D reconstruction, from which the percentage of void volume was calculated. Data were analyzed using two-way analysis of variance and Tukey post hoc test at a preset alpha of 0.05. RESULTS: The conventional insertion method resulted in reduced porosity, compared with sonic insertion, for SureFil SDR Flow and Tetric EvoCeram bulk fill. The sonic insertion method did not demonstrate any influence on void formation for Herculite Ultra or SonicFill. CONCLUSION: Results suggest that the sonic insertion method might increase void formation during resin composite delivery, depending on restorative material brand.

Gingival Fluid Inflammatory Biomarkers and Hypertension in African Americans.

Hypertension and periodontitis are highly prevalent among African Americans. This cross-sectional study investigated the relationships among inflammatory biomarkers in the gingival fluid, periodontitis, and blood pressure in these individuals. Twenty-one subjects who reported a diagnosis of hypertension and a comparison group of 26 nonhypertensive participants were enrolled. All were African Americans, non-cigarette smoking, and free from other systemic illness. Blood pressure and body mass index were assessed. A comprehensive periodontal examination was performed. Gingival fluid was collected from 3 healthy sites and 3 diseased sites when available. Samples were assessed for 8-isoprostane, interleukin 1ß, monocyte chemoattractant protein 1, tumor necrosis factor-alpha (TNFα), C-reactive protein (CRP), and matrix metalloproteinase 8. Regardless of hypertension status, diseased sites were associated with increased levels of these biomarkers. CRP and TNFα levels were also significantly higher in hypertensive than nonhypertensive individuals without diseased sites. After adjusting for demographics and body mass index, periodontal attachment loss was higher among hypertensive than nonhypertensive subjects. TNFα and CRP levels and hypertension were in the same association pathway with attachment loss. Elevated blood pressure may increase the risk of periodontitis through a localized inflammatory mechanism. Knowledge Transfer Statement: The results of this study can be used by clinicians to better understand the etiology and pathogenesis of periodontitis in hypertensive individuals in general and African Americans in particular. The information could lead to better management of periodontal disease.

Microcomputed Tomography Evaluation of Polymerization Shrinkage of Class I Flowable Resin Composite Restorations.

The present study aimed to characterize the pattern and volume of polymerization shrinkage of flowable resin composites, including one conventional, two bulk fill, and one self-adhesive. Standardized class I preparations (2.5 mm depth × 4 mm length × 4 mm wide) were performed in 24 caries-free human third molars that were randomly divided in four groups, according to the resin composite and adhesive system used: group 1 = Permaflo + Peak Universal Bond (PP); group 2 = Filtek Bulk Fill + Scotchbond Universal (FS); group 3 = Surefil SDR + XP Bond (SX); and group 4 = Vertise flow self-adhering (VE) (n=6). Each tooth was scanned three times using a microcomputed tomography (µCT) apparatus. The first scan was done after the cavity preparation, the second after cavity filling with the flowable resin composite before curing, and the third after it was cured. The µCT images were imported into three-dimensional rendering software, and volumetric polymerization shrinkage percentage was calculated for each sample. Data were submitted to one-way analysis of variance and post hoc comparisons. No significant difference was observed among PP, FS, and VE. SX bulk fill resin composite presented the lowest values of volumetric shrinkage. Shrinkage was mostly observed along the occlusal surface and part of the pulpal floor. In conclusion, polymerization shrinkage outcomes in a 2.5-mm deep class I cavity were material dependent, although most materials did not differ. The location of shrinkage was mainly at the occlusal surface.

Attention, memory, and motor skills as childhood predictors of schizophrenia-related psychoses: the New York High-Risk Project.

OBJECTIVE: Childhood neurobehavioral deficits in offspring of schizophrenic, affectively ill, and psychiatrically normal parents were evaluated as predictors of schizophrenia-related psychoses in adulthood. METHOD: The offspring were tested with neurobehavioral measures at 7-12 years of age and assessed in mid-adulthood for axis I diagnoses. The relationships of childhood deficits in attention, verbal memory, and gross motor skills to adulthood schizophrenia-related psychoses were examined in separate path analyses by using logistic regression equations. Sensitivity and specificity were determined for each of the childhood dysfunctions. RESULTS: For the offspring of schizophrenic parents, childhood deficits in verbal memory, gross motor skills, and attention identified 83%, 75%, and 58%, respectively, of the subjects with schizophrenia-related psychoses; 50% were identified by all three variables combined. False positive rates in subjects who did not develop schizophrenia-related psychoses ranged from 18% for those with deficits in attention during childhood to 28% for those with deficits in memory. The three variables had low deficit rates in the offspring of the other two parental groups and were not associated with other psychiatric disorders in any group. CONCLUSIONS: Schizophrenia-related psychoses in adulthood are distinguished in subjects at risk for schizophrenia by childhood deficits in verbal memory, gross motor skills, and attention. The findings suggest that deficits in these variables are relatively specific to schizophrenia risk and may be indicators of the genetic liability to schizophrenia.

A placebo-controlled study of fluoxetine versus imipramine in the acute treatment of atypical depression.

OBJECTIVE: The atypical subtype of depression appears to be both well validated and common. Although monoamine oxidase inhibitors are effective in treating atypical depression, their side effects and prescription-associated dietary restrictions reduce their suitability as a first-line treatment. The objective of this study was to estimate the efficacy of the selective serotonin reuptake inhibitor (SSRI) fluoxetine in the treatment of major depression with atypical features. METHOD: One hundred fifty-four subjects with DSM-IV major depression who met the Columbia criteria for atypical depression were randomly assigned to receive fluoxetine, imipramine, or placebo for a 10-week clinical trial. Imipramine was included because its known efficacy for treatment of atypical depression helped to calibrate the appropriateness of the study group. RESULTS: In both intention-to-treat and completer groups, the effectiveness of both fluoxetine and imipramine was significantly better than that of placebo. The two medications did not differ from each other in effectiveness. Significantly more patients dropped out of treatment with imipramine than with fluoxetine. Before treatment, patients on average rated themselves as very impaired on psychological dimensions of general health and moderately impaired on physical dimensions, compared with population norms. The self-ratings of patients who responded to treatment essentially normalized on these measures. CONCLUSIONS: Despite earlier data that SSRIs might be the treatment of choice, fluoxetine appeared to be no better than imipramine in the treatment of atypical depression, although fluoxetine was better tolerated than imipramine.

Central poststroke pain and Wallenberg's lateral medullary infarction: frequency, character, and determinants in 63 patients.

UNLABELLED: Central poststroke pain (CPSP) is an infrequently recognized complication of lateral medullary infarction (LMI). We determined the frequency, nature, and predictors of this complication in 63 patients with LMI. The hypothesis tested was that the degree of clinical sensory loss and extent of infarction seen on MRI, both graded by a predetermined scoring scale, would be predictive of CPSP. We also performed quantitative sensory testing (QST) of thermal and pressure sensation thresholds in a subgroup of 19 patients (nine with CPSP and 10 without) to analyze in detail the spinothalamic and trigeminothalamic systems mediating these modalities from both sides of the face and body. We analyzed these results for specific markers of CPSP. RESULTS: CPSP developed in 25% (16/63) of the patients, all within 6 months. This was constant and severe with frequent allodynia, but responded in all cases to amitriptyline and recurred promptly on attempted weaning. CPSP affected the ipsilateral peri-orbital region most commonly, either alone or in combination with the contralateral limbs. Ipsilateral neurotrophic facial ulceration developed in two cases. CPSP correlated significantly (Fisher's exact test, p < 0.0002) with the degree of clinical sensory loss but not with the size of infarction seen on MRI (Fisher's exact test, p = 0.7). QST revealed a highly specific (100%) and sensitive (89%) finding for CPSP-thresholds from the check contralateral to the LMI were normal in eight of nine cases with CPSP and abnormal in all of the 10 cases without CPSP. Abnormalities in the face contralateral to the infarct are referable to the crossed trigeminothalamic tract in the medullary reticular formation medial to the infarcted lateral medulla. We conclude that this argues for the theory that central pain is caused by denervation sensitivity of the "paleo"-reticulothalamic connections due to a selective "neo"-spinothalamic lesion.

On the absence of correlation between responses to noxious heat, cold, electrical and ischemic stimulation.

Is a person's response to one noxious stimulus similar to his/her responses to other noxious stimuli? This long-investigated topic in pain research has provided inconclusive results. In the present study, 2 samples were studied: one using 60 healthy volunteers and the other using 29 patients with coronary artery disease. Results showed near-zero correlations between measures of heat, cold, ischemic, and electrical laboratory pains, as well as between these laboratory pains and an idiopathic pain, the latency to exercise-induced angina in the patients. Power analyses showed that the sample sizes were sufficient to detect a correlation of 0.50 or greater at the 0.05 level 99% of the time in the healthy volunteers, and between 80 and 85% of the time in the patients. Reliability analyses indicated retest correlations on the order of 0.60 for these measures, indicating that the lack of correlation between modalities was not due to unreliability within a measure. These studies fail to demonstrate alternate-forms reliability among these tests, and also fail to support the notion that a person can be characterized as generally stoical or generally complaining to any painful stimulus. In practice, this implies that a battery of tests should generally be used to assess pain sensitivity and also that assessments of one pain modality are not generally useful for making inferences about another.

Altered pain and visual sensitivity in humans: the effects of acute and chronic stress.

In the runner study, as measured by tourniquet ischemic pain, exercise stress produced hypoalgesia 20 minutes post-run, followed by hyperalgesia and euphoria at 30 minutes. The hypoalgesia and euphoria were reversed by naloxone. Exercise stress also produced a decrease in P(A), suggesting hypoalgesia to the thermal cutaneous stimulation. However, this analgesia was not naloxone reversible. Nor did exercise stress produce analgesia to cold-pressor pain. In the acupuncture study, noxious electrical stimulation of classical acupuncture sites failed to produce analgesia either during or after stimulation. However, expectation did produce a change in the pain report criterion, but only in the acupunctured arm. Noxious electrical stimulation (TENS) of the median nerve produced no analgesia outside of the related segmental area, that is, acute electrical pain did not produce generalized hypoalgesia. Thus, the effects of the stress produced by noxious electrical stimulation differ from that produced by exercise. In contrast to the results of the acute pain studies, chronic clinical pain, which combines mental stress and pain stress, produced strong hypoalgesia and anesthesia. Again, in contrast to the acute experimental pain studies, the emotional stress of mental illness produces hypoalgesia, but not anesthesia. Finally, the somatosensory system is not the only the sensory system affected by stress. Cold-pressor pain decreases visual sensitivity both during and for a few minutes following stimulation, and does not interfere with short-term (supra-digit span) memory.