Tumor progression in tympanojugular paragangliomas: the role of radiotherapy and wait and scan

INTRODUCTION

Tympanojugular paragangliomas (TJ PGLs) are rare tumors characterized by bone infiltration and erosion and a close relationship with critical structures, such as cranial nerves and internal carotid artery. For these reasons, their management represents a tough challenge. Since the fifties, radio-therapy (RT) has been proposed as an alternative treatment aimed at avoiding tumor progression. However, the indolent nature of the tumor, characterized by slow growth, is a crucial factor that needs to be considered before offering radiation.

METHODS

This study aims to examine tumor progression in RT patients through a systematic review of the literature and in TJ PGL patients who underwent solely wait and scan at our department.

RESULTS

The rate of tumor progression in the RT group was 8.9%, while in the wait and scan cohort was 12.9%. This data suggests the innate slow growth of PGLs. However, it is not possible to draw certain conclusions because of the wide heterogeneity of the studies.

CONCLUSION

When complete surgical excision of TJ PGLs is not feasible, appropriate counseling and patient selection, including comprehensive tumor classification, should be performed before proposing RT to control tumor progression, since wait and scan may represent a reasonable option in selected cases.

Audiovestibular Findings in Patients with Concurrent Superior Canal Dehiscence and Vestibular Schwannoma

OBJECTIVE

To describe the clinical-instrumental findings in case of concurrent superior canal dehiscence (SCD) and ipsilateral vestibular schwannoma (VS), aiming to highlight the importance of an extensive instrumental assessment to achieve a correct diagnosis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Five patients with concurrent SCD and VS.

INTERVENTION

Clinical-instrumental assessment and imaging.

MAIN OUTCOME MEASURE

Clinical presentation, audiovestibular findings, and imaging.

RESULTS

The chief complaints were hearing loss (HL) and unsteadiness (80%). Other main symptoms included tinnitus (60%) and pressure-induced vertigo (40%). Mixed-HL was identified in three patients and pure sensorineural-HL in 1, including a roll-over curve in speech-audiometry in two cases. Vibration-induced nystagmus was elicited in all cases, whereas vestibular-evoked myogenic potentials showed reduced thresholds and enhanced amplitudes on the affected side in three patients. Ipsilesional weakness on caloric testing was detected in three patients and a bilateral hyporeflexia in one. A global canal impairment was detected by the video-head impulse test in one case, whereas the rest of the cohort exhibited a reduced function for the affected superior canal, together with ipsilateral posterior canal impairment in two cases. All patients performed both temporal bones HRCT scan and brain-MRI showing unilateral SCD and ipsilateral VS, respectively. All patients were submitted to a wait-and-scan approach, requiring VS removal only in one case.

CONCLUSION

Simultaneous SCD and VS might result in subtle clinical presentation with puzzling lesion patterns. When unclear symptoms and signs occur, a complete audiovestibular assessment plays a key role to address imaging and diagnosis.

Superior petrosal vein sacrifice in translabyrinthine approach for resection of vestibule schwannoma

PURPOSE

The aim of this study was to evaluate the safety and surgical outcome of superior petrosal vein (SPV, Dandy's vein) sacrifice in translabyrinthine approach (TLA) for resection of vestibule schwannoma (VS) as compared with SPV preservation, with further investigation of preoperational factors associated with the implement of SPV sacrifice.

METHODS

The authors prospectively collected data from patients surgically treated for VS through TLA between June 2021 and April 2022 at the Gruppo Otologico.

RESULTS

There were 30 and 49 patients in SPV sacrifice and preservation groups, respectively. SPV sacrifice group had significantly larger tumor size (2.46 vs. 1.40 cm), less percentage of solid tumor (26.7% vs. 83.7%), higher incidence of brainstem compression (80% vs. 26.5%), and higher percentage of facial numbness (20.0% vs. 4.1%) than SPV preservation group. Gross total resection (GTR) rates were 73.3% after SPV sacrifice and 87.8% after SPV preservation. Facial nerve preservation rates were similar. No complication related with SPV sacrifice was observed. Logistic regression analysis showed tumor size and complete solid consistency as significant risk factors associated with SPV sacrifice. ROC curve further demonstrated tumor size as a fair predictor (AUC = 0.833), with optimum cutoff value of 1.68 cm.

CONCLUSION

SPV sacrifice via TLA as needed is a safe and effective maneuver for removal of relatively large VS. Tumor size and consistency can be used as a guidance in preoperational decision-making, with cutoff value of 1.68 cm and cystic formation as predictive indicators.

Monitoring the Epidemiology of Otitis Using Free-Text Pediatric Medical Notes: A Deep Learning Approach

Free-text information represents a valuable resource for epidemiological surveillance. Its unstructured nature, however, presents significant challenges in the extraction of meaningful information. This study presents a deep learning model for classifying otitis using pediatric medical records. We analyzed the Pedianet database, which includes data from January 2004 to August 2017. The model categorizes narratives from clinical record diagnoses into six types: no otitis, non-media otitis, non-acute otitis media (OM), acute OM (AOM), AOM with perforation, and recurrent AOM. Utilizing deep learning architectures, including an ensemble model, this study addressed the challenges associated with the manual classification of extensive narrative data. The performance of the model was evaluated according to a gold standard classification made by three expert clinicians. The ensemble model achieved values of 97.03, 93.97, 96.59, and 95.48 for balanced precision, balanced recall, accuracy, and balanced F1 measure, respectively. These results underscore the efficacy of using automated systems for medical diagnoses, especially in pediatric care. Our findings demonstrate the potential of deep learning in interpreting complex medical records, enhancing epidemiological surveillance and research. This approach offers significant improvements in handling large-scale medical data, ensuring accuracy and minimizing human error. The methodology is adaptable to other medical contexts, promising a new horizon in healthcare analytics.

Association between rainfall and Escherichia coli in live bivalve molluscs harvested in Sardinia, Italy

Rainfall is generally accepted as one of the most important factors associated with an increased level of E. coli in bivalve molluscs. Performing microbiological risk assessment is relevant to official control authorities to determine the sanitary status of harvesting areas and, therefore, develop monitoring strategies and identify management practices that could be used to improve the quality and safety of the final product. The present study aimed to investigate the impact of rainfall on the content of E. coli in bivalve molluscs farmed in Sardinia (Italy). Enumeration of E. coli was performed according to the Most Probable Number (MPN) method (ISO 16649-3) on 1,920 bivalve samples collected from 7 regional counties between 2018 and 2020. Bivalve molluscs samples included 955 mussels (Mytilus galloprovincialis), 500 oysters (Crassostrea gigas), 325 clams (Ruditapes decussatus), 94 warty venus (Venus verrucosa), and 46 lagoon cockles (Cerastoderma glaucum). Rainfall data were obtained by the Department of Meteorology of the ARPA Sardegna. For each sampling site, GPS coordinates were used to identify gauge stations within catchment areas. Cumulative rain (mm) was recorded 1, 3, 5, 7, and 15 days before sampling, among which the 7-day cumulative rain was the strongest predictor of E. coli counts. Several thresholds of 7-day cumulative rain (from <10 mm up to >300 mm) before sampling were used to estimate the chances of a non-compliant sample (E. coli levels above the limit for sanitary class A; 230 MPN/100 g). The 7-day cumulative rain was positively associated with the chances of non-compliance. When the 7-day cumulative rain before sampling was >300 mm, 80.5 % of the samples were non-compliant, and the odds of a non-compliant sample were 23.6 times higher, as compared to samples harvested when the 7-day cumulative rainfall was <10 mm. Precipitation data could be a useful tool for interpreting anomalous results from official control authorities and reduce the costs that originate from closure of production areas.

Impaired Vestibulo-Ocular Reflex on Video Head Impulse Test in Superior Canal Dehiscence: "Spontaneous Plugging" or Endolymphatic Flow Dissipation?

Surgical plugging of the superior semicircular canal (SSC) represents an effective procedure to treat disabling symptoms in superior canal dehiscence (SCD), despite resulting in an impaired vestibulo-ocular reflex (VOR) gain for the SSC. On the other hand, SSC hypofunction on video head impulse test (vHIT) represents a common finding in patients with SCD exhibiting sound/pressure-induced vertigo, a low-frequency air-bone gap (ABG), and enhanced vestibular-evoked myogenic potentials (VEMPs). "Spontaneous canal plugging" has been assumed as the underlying process. Nevertheless, missing/mitigated symptoms and/or near-normal instrumental findings would be expected. An endolymphatic flow dissipation has been recently proposed as an alternative pathomechanism for SSC VOR gain reduction in SCD. We aimed to shed light on this debate by comparing instrumental findings from 46 ears of 44 patients with SCD exhibiting SSC hypofunction with post-operative data from 10 ears of 10 patients with SCD who underwent surgical plugging. While no difference in SSC VOR gain values was found between the two groups (p = 0.199), operated ears developed a posterior canal hypofunction (p = 0.002). Moreover, both ABG values (p = 0.012) and cervical/ocular VEMP amplitudes (p < 0.001) were significantly higher and VEMP thresholds were significantly lower (p < 0.001) in ears with SCD compared to operated ears. According to our data, canal VOR gain reduction in SCD should be considered as an additional sign of a third window mechanism, likely due to an endolymphatic flow dissipation.

Late complications of cochlear implant: a case report of necrotizing meningoencephalitis similar to a CPA tumor

OBJECTIVE

Report a case of localized necrotizing meningoencephalitis as the cause of functional hearing loss after cochlear implant (CI) surgery.

CASE REPORT

A 12-year-old with bilateral CI presented to our quaternary center due to severe functional hearing loss after 11 years since left ear CI surgery. CT with contrast was conducted showing a CPA tumor-like mass. Pre-operative computed tomography (CT) scans and magnetic resonance imaging (MRI) performed at the age of 1 year showed no inner ear abnormalities and in particular no evidence of a tumor in the cerebellopontine angle (CPA).

CONCLUSION

Following removal of the CI and the mass, histopathological, immunohistochemical and cultural examinations revealed a necrotizing meningoencephalitis, with the CI electrode as the focus.

Management of Vestibular Schwannoma with Normal Hearing

INTRODUCTION

This work aimed to study the management of vestibular schwannoma (VS) patients with normal hearing (NH).

METHODS

A retrospective study was undertaken in a Quaternary referral center for skull base pathologies. Among 4,000 VS patients 162 met our strict audiological criteria for NH. These patients were divided into 2 management groups, wait and scan (W&S) (45/162, 25%) and operated patients (123/162, 75%), and 6 patients were included in both groups.

RESULTS

Our management strategy achieved the goals for treatment of VS. First goal, all tumors were completely removed except for 2 intentional residuals. Second goal, facial nerve (FN) function preservation (House Brackmann I, II, and III) was 95.9%. Third goal, possible hearing preservation (HP) attempts occurred in (50/122) (40.9%) with an HP rate in 44% of the patients. Additionally, there were only 2 cases of postoperative complications with no CSF leakage. The prospect of HP in NH patients did not differ with respect to tumor size. However, patients with normal preoperative ABR seemed to have better chances of HP and good FN function and vice versa. HP rate was superior for the MCFA as opposed to the RS + RLA. W&S group demonstrated hearing stability in 88.9% of the patients and FN function stability of HB I in 100% of the patients.

CONCLUSIONS

Surgical resection is a reasonable and definitive management option for VS with NH. Nevertheless, choosing to manage cases with observation remains an appropriate management option for NH patients. ABR might be considered as an adjuvant tool indicating better prognosis for HP.

Analysis of Prognostic Factors Impacting Pediatric Acute Mastoiditis Outcomes

BACKGROUND

This study aimed to investigate the outcomes of pediatric patients with acute mastoiditis while examining the role of intravenous steroid therapy, patient demographics, and serum inflammatory values as prognostic factors.

METHODS

This study is a single-center retrospective observational study including 73 consecutive patients treated for acute mastoiditis in the course of the 10-year study period (January 2010 to December 2019).

RESULTS

Data analysis showed that patients requiring surgical treatment (14%) had a 3-fold higher C-reactive protein value at admission compared to those treated conservatively (P < .001). Receiver operating characteristic analysis revealed that a C-reactive protein cut-off of ≥98.7 had a sensitivity and specificity of 100% and 74.6%, respectively, for predicting the need for surgery (area under the curve=0.927, P < .001). The duration of symptoms before hospitalization was nearly 2 days shorter in male patients (P=.031), and the use of intravenous steroid therapy significantly shortened the length of hospitalization (P=.023), by 1.4 days on average.

CONCLUSION

Intravenous steroid therapy may be useful in decreasing the length of hospital stay. Mastoiditis tends to present more severely in male patients, and monitoring C-reactive protein values during treatment correlated well with the need for surgery.

The otologic approach in the management of posterior petrous surface meningiomas

PURPOSE

Report our experience in the management of posterior petrous surface meningiomas (PPSMs), and identify features that affect hearing, facial nerve (FN) function, and control of the disease.

METHODS

Retrospective case series of 131 patients surgically managed for PPSMs. FN status, hearing and tumour radicality were assessed and compared between patients with tumours of different locations (Desgeorges classification) and internal auditory canal involvement (IAC).

RESULTS

At the time of surgery 74.8% of patients had a hearing loss. Hearing was mostly unserviceable in tumors attached to the meatus. Pure tone audiometry did not correlate to IAC extension, while speech discrimination scores were statistically worse when the tumor occupied the IAC (unpaired t test, p = 0.0152). Similarly, extrameatal tumors undergoing removal by otic preserving techniques maintained postoperative hearing, whereas hearing worsened significantly in tumors involving the IAC (paired t test, p = 0.048). The FN was affected preoperatively in 11.4% of cases. Postoperative FN palsy was significantly correlated to the IAC involvement (Fisher's exact test, p = 0.0013), while it was not correlated to tumor size. According to the Desgeorges classification, a postoperative FN palsy complicated the majority of anteriorly extending tumors and, two-fifths of meatus centred tumors. 75% of posterior located tumors had a postoperative FN grade I HB.

CONCLUSIONS

Since the involvement of the IAC by the tumor affects both hearing and FN function, the IAC is of primary importance in PPSMs and should be studied and addressed as much as the tumor location in the CPA.

Proactive Risk Assessment Through Failure Mode and Effect Analysis (FMEA) for Haemodialysis Facilities: A Pilot Project

Haemodialysis (HD) is one of the methods for renal replacement therapy in the management of advanced chronic kidney disease through an osmosis process that allows purification of blood in the dialysis machine. The complexity of the dialytic procedure often requires the presence of a multi-specialist, multi-disciplinary team. The dialysis process is an important target for clinical risk management. Failure Mode and Effect Analysis (FMEA) is a proactive technique, considered a purposeful and dynamic tool for clinical risk management. FMEA is noted in five phases that allow a preliminary assessment of a definite process through identification and classification of risk priorities. This study represents the first of a two-phase project where FMEA is applied to HD in the setting of San Feliciano Hospital. The dialysis center performs ~12,000 dialysis sessions per year. The dialysis process is divided into different stages. A total of 31 failure modes were identified in the whole dialysis stages; more than 2/3 of the failure modes were related to the only connecting of the patient to the dialysis machine. The first phase of the study clearly remarked that the most critical step of the dialytic process is represented by the connection between the patient and the machine, as expected. Indeed, in order to have the dialysis set up, an arteriovenous fistula must be surgically created prior to the procedure and it is one of the most important issues in the HD process because of the necessity of a constant revision of it. FMEA application to HD is a useful tool, easy to be implemented and it is likely to nimbly reveal the practical and potential solutions to the critical steps of the procedure.

Comparison of Lower Cranial Nerve Function Between Tympanojugular Paraganglioma Class C1/C2 With and Without Intracranial Extension: A Four-Decade Experience

OBJECTIVE

To compare preoperative and postoperative lower cranial nerve (LCN) function between Class C1 and C2 tympanojugular paraganglioma (TJP) with/without intracranial intradural (Di)/extradural (De) extensions, according to the experience of a single surgeon over four decades.

STUDY DESIGN

Retrospective review.

SETTING

Quaternary referral center for otology and skull base surgery.

MATERIAL AND METHODS

A chart review was conducted of all the patients operated for C1/C2 TJPs from September 1983 to December 2018. The tumors were classified as: Limited-Group (C1/C2 without Di/De extensions) and Extended-Group (C1/C2 with Di/De extensions).

RESULTS

Of 159 patients, 107 (67.3%) were women; the mean age at surgery was 46.5 years. The Limited-Group (56.6%) comprised C1 (41.1%) and C2 (58.9%) tumors; the Extended-Group (43.4%) comprised C1+Di/De (14.5%) and C2+Di/De (85.5%) tumors. The prevalence of preoperative LCN palsy was 11.9 times higher in Extended than Limited tumors: 61.9% versus 4.9% (p < 0.05). The risk for postoperative LCN palsy was 4.7 times greater in Extended than Limited tumors: 29.2% versus 12.9%, p = 0.01.

CONCLUSION

Especially in younger patients, complete removal of Limited C1/C2 tumors, before they extend intracranially, reduces the risk of dysfunctionality of LCNs and the burden of residual tumor. The incidence of new tumors increased over four decades. However, new-postoperative LCN palsy did not occur in any Limited C1/C2 tumors operated after the year 2000, and declined to less than 10% of Extended C1/C2 tumors.

Long term outcomes of canal wall up and canal wall down tympanomastoidectomies in pediatric cholesteatoma

Cholesteatomas in children have a more aggressive growth pattern compared to adults, which leads to a higher incidence of both residual and recurrent disease. A staged canal wall-up or a canal wall-down tympanomastoidectomy (CWUT and CWDT, respectively) is selected depending on the extent of the disease and condition of the middle ear (ME) cleft and mastoid. Endoscopic ear surgery (EES) has been recently introduced as an adjuvant tool for the treatment of this pathology even in the pediatric population.

OBJECTIVES

To analyze long term outcomes of CWUT and CWDT in the pediatric population, focusing on residual and recurrence rates of cholesteatoma and hearing results. A literature review including cases treated with EES were discussed.

MATERIAL AND METHODS

Pediatric patients treated for cholesteatoma involving both the ME and mastoid with a follow-up (FU) of at least 4 years were retrospectively analyzed in a quaternary referral center for otology and lateral skull base surgery. Patients were grouped according to the surgical technique (CWUT versus CWDT). Rates of residual and recurrent cholesteatoma after each surgical technique were reported and compared. Mean Air-Bone Gap (ABG) of 0.5-1-2-4 KHz was measured and reported before the first surgery and at the last post-operative FU.

RESULTS

Two-hundred and thirty-six cases fulfilled our inclusion criteria. The mean FU was 100.4 ± 44.2 months (median 89 months). One-hundred and five (44.5%) cases underwent a CWUT, whereas 131 (55.5%) a CWDT. A second stage surgery was performed in 73.5% of CWUT and 58.7% of CWDT. Among the CWUT group, residual cholesteatoma occurred in 22 (21%) ears and recurrence in 24 (22.9%). Patients undergoing CWDT showed lower rates of both residual and recurrent cholesteatoma (7.6% and 2.3%, respectively). ABG improvement was noted for both groups, even though CWUT showed better post-operative hearing results.

CONCLUSIONS

The CWDT technique offers a definite surgical therapy, with minimal residual and recurrence rates and audiological results comparable to the CWUT technique. EES must still prove its added benefit or equivalence to pure microscopic approaches.

A qualitative study on the consequences of workplace violence in psychiatric settings

Background

Violence against health care workers in psychiatric settings presents worrying data in the literature. Violence effects for healthcare professionals and organizations are absence from work for injury or illness, decreased job satisfaction and lower quality of work. The aim of the study was to identify the consequences of violence on health, work habits and performance of nurses who work with psychiatric patients.

Methods

The study was carried out by using a semi-structured interview with 12 nurses from different hospital and territorial psychiatric settings in Southern Italy. The interviews were conducted from July to October 2020 by telephone and recorded with the consent of the participants. The collected data were transcribed and analyzed.

Results

The data show that 91.7% of the interviewees were assaulted by patients. Eight nurses (66.7%) were aggressed several times and six (50%) suffered physical violence. The narratives revealed that patients mainly suffered from drug addiction and that half of them were on pharmacological treatment. Nurses reported feelings of anger, helplessness, fear and frustration; five nurses experienced health consequences, including low mood, anxiety, stress and nervousness. Some of them described pain from physical injuries and permanent effects caused by the assault. An attacked nurse has been absent from work for injury. The aggressions resulted in a change of nurses' work habits and performances; they were more careful after the aggression and modified their approach to the patient. Some of them developed skills and strategies to protect themselves and avoid aggression, others developed greater faith in the efficacy of the prescribed drug. However, the events also caused job dissatisfaction.

Conclusions

Aggression has a negative impact on nurses' health and work performance. Healthcare organizations should take into account the self-protection strategies identified by professionals and support them to prevent violence.

Key messages

Violence at work compromises nurses' health and work performance in psychiatric settings. Safer work settings could improve nurses' job satisfaction and the quality of patient care.

Resting Energy Expenditure in the Elderly: Systematic Review and Comparison of Equations in an Experimental Population

Elderly patients are at risk of malnutrition and need an appropriate assessment of energy requirements. Predictive equations are widely used to estimate resting energy expenditure (REE). In the study, we conducted a systematic review of REE predictive equations in the elderly population and compared them in an experimental population. Studies involving subjects older than 65 years of age that evaluated the performance of a predictive equation vs. a gold standard were included. The retrieved equations were then tested on a sample of 88 elderly subjects enrolled in an Italian nursing home to evaluate the agreement among the estimated REEs. The agreement was assessed using the intraclass correlation coefficient (ICC). A web application, equationer, was developed to calculate all the estimated REEs according to the available variables. The review identified 68 studies (210 different equations). The agreement among the equations in our sample was higher for equations with fewer parameters, especially those that included body weight, ICC = 0.75 (95% CI = 0.69-0.81). There is great heterogeneity among REE estimates. Such differences should be considered and evaluated when estimates are applied to particularly fragile populations since the results have the potential to impact the patient's overall clinical outcome.

SARS-CoV-2 systemic infection in a kidney transplant recipient: sequence analysis in clinical specimens

OBJECTIVE

Herein we report clinical and virological data in a patient with COVID-19 infection and a prior history of kidney transplantation who had a good clinical recovery despite systemic infection.

PATIENTS AND METHODS

Reverse transcriptase quantitative PCR analysis for the RdRp, N and E target genes detected viral RNA in different types of biological specimens. Whole viral genome sequences were obtained and analyzed from respiratory tract, feces and blood.

RESULTS

Viral sequences showed high (~99.9%) homology with the Wuhan seafood market pneumonia virus. Phylogenetic analysis assigned of the SARS-CoV-2 strains to clade G. A rare variant in the orf1ab gene was present in both sequences, while a missense variant was detected only in viral RNA from stool.

CONCLUSIONS

The evolution of the COVID-19 systemic infection in the patient presented here was favorable to the hypothesis that immunosuppressive therapy in organ transplant recipients might be involved in viral dissemination. A missense mutation was present in only one specimen from the same patient implying the occurrence of a mutational event in viral RNA, which is suggestive for the presence of an active virus, even though viral isolation is necessary to demonstrate infectivity.

Management of squamous cell carcinoma of the temporal bone: long-term results and factors influencing outcomes

OBJECTIVE

Temporal bone squamous cell carcinoma (TBSCC) is a rare, aggressive tumor. Surgery, alone or combined with radiotherapy, represent the mainstay of treatment. To report our experience in the treatment of TBSCC and evaluate the disease-specific survival, identifying the factors influencing this outcome.

MATERIALS AND METHODS

A retrospective study was performed on 66 patients between 1993 and 2018. Patients were staged according to the University of Pittsburgh-modified TNM staging system. Nine cases (13.6%) were Stage I, 7 cases (10.6%) Stage II, 20 cases (30.3%) Stage III and 30 cases (45.5%) Stage IV. Twenty-four patients underwent lateral temporal bone resection (LTBR) and 42 patients underwent subtotal temporal bone resection (STBR).

RESULTS

One hundred percent of Stage I and II patients showed no evidence of disease (NED) after a median follow-up of 101 months (range 1-289 months). NED resulted in 88.2% of Stage III (mean follow-up 80.3 months; range 8-257) and 46.4% of stage IV (mean follow-up 50.6 months; range 3-217). Pittsburgh Stage or involvement of mastoid, facial nerve, medial wall of the middle ear, temporomandibular joint and middle fossa dura emerged as negative prognostic factors. The highest mortality rate occurred in the first 2 years after treatment, due to local recurrence.

CONCLUSIONS

Prognosis of TBSCC can be excellent in early stage tumors, employing a LTBR. In more advanced cases, prognosis is poor. STBR with adjuvant radiotherapy represents the treatment of choice, offering acceptable survival rates. Given the rarity of the pathology, many controversies still exist concerning optimal management.

The endolymphatic sac tumor: challenges in the eradication of a localized disease

OBJECTIVE

Identify the critical points that lead to recurrences and lack of radicality in endolymphatic sac tumors (ELSTs).

STUDY DESIGN

Retrospective case study and review of the literature.

SETTING

Tertiary referral center.

PATIENTS

Thirteen cases of ELST were included in the study and their preoperative, intraoperative and postoperative data were analyzed and compared to a review of the literature.

INTERVENTION(S)

Therapeutical.

MAIN OUTCOME MEASURE(S)

Prevalence of recurrent and residual tumors, comparison to the literature and analysis of ELST characteristics.

RESULTS

Diagnosis was made 26 ± 17 months after the onset of symptomatology, and an ELST was preoperatively suspected in only six cases. At the time of surgery, 10 patients suffered from hearing loss. Preoperative symptoms or audiometry could not predict labyrinth infiltration, although speech discrimination scores were significantly associated with labyrinth infiltration (p = 0.0413). The labyrinth was infiltrated in 8 cases (57.1%), and in 7 cases (46.7%) the tumor eroded the carotid canal, whereas 6 cases (40%) presented an intradural extension. A gross total resection was achieved in 11 cases. There were two residual tumors, one of which because of profuse bleeding, and one recurrence (23.1%). A mean of 22.8% of recurrent or residual tumors are described in the literature based on 242 published cases, in more than half of the cases as a consequence of subtotal tumor resection (STR).

CONCLUSIONS

Recurrence derives mostly from the difficulty to identify the extension of the tumor due to the extensive bone infiltration. Accurate diagnosis and correct preoperative planning, with embolization when possible, will facilitate surgery and avoid STR due to intraoperative bleeding. Long follow-ups are important in order to avoid insidious recurrences.

Study of submerged cases of violence on healthcare workers in an emergency department

Background

Violence at work has negative effects on both workers and organizations. Among healthcare workers, nurses are the professionals most at risk, especially those who work in emergency departments. However, literature data are estimated to be the tip of the iceberg. The study aims at analyze violence events that are not reported by professionals via common reporting system, in order to measure the real extent of the problem and allow the organizations introducing adequate prevention measures.

Methods

The study took place in November 2016 in an emergency department in Southern Italy. A retrospective analysis was carried out by reviewing both the delivery registers (DR) used by nurses and doctors during the service, and the reports of security guards (RSG), in the period between 2011 and 2015.

Results

The results show that violence frequency was higher than that present in the risk management reporting (only one case). In the DR, 40 violence events were reported, yet in the RSG, 109 cases were registered. More nurses (n = 33) than doctors (n = 8) reported violence events in the DR. In the RSG, guards reported the same number of cases involving nurses, and 26 cases for doctors. In 50 cases, the professional involved was not specified. The violence type was physical (5 DR vs 13 RSG), physical threats or attempted violence (4 DR vs 13 RSG), and verbal (24 DR vs 67 RSG). Weapons (e.g., knife, hammer, syringe) were used in 2 cases as reported in DR and in 4 cases according to RSG. The aggressor was mainly the patient (15 DR vs 83 RSG) and the companion (14 DR vs 16 RSG). The shifts with more frequency of events are afternoon (15 DR vs 40 RSG) and night (12 DR vs 48 RSG).

Conclusions

The data show an amount of submerged cases and highlight a discrepancy between report of professionals and violence events where security guards intervened.

Key messages

Under-reporting violence cases require attention by the organizations. Prevention and protection strategies must be implemented. The use of the reporting system must be improved.

Comparison of fall risk assessment scales in the triage of an Italian emergency department

Background

Falls in hospital are adverse events with serious consequences for the patient. Fall risk assessment requires easy tools that are suitable for the specific clinical context. This is important to quickly identify preventing measures. The aim of the study is to identify an appropriate scale for assessing fall risk in patients from an emergency department.

Methods

For the fall risk assessment in the emergency department, three scales were identified in literature: Kinder 1, MEDFRAT, and Morse. MEDFRAT and Morse classify the patient in high, moderate, and low risk; Kinder 1 split patients “at risk” (also when there is only one positive item) and “non-risk” (in which all items are negative). The study was carried out in July 2019 in an Italian emergency department. Patients who arrived in triage were assessed for the fall risk using the three scales.

Results

On a sample of 318 patients, the used scales show different levels of fall risk. For Kinder 1, 83.02% is at risk and 16.98% is not at risk; for MEDFRAT, 14.78% is at high risk, 15.09% moderate, and 70.13% low risk; for Morse, 8.81% is at high risk, 35.53% moderate, and 56.66% low risk. As Kinder 1 implies as “high risk” that all items of the questionnaire are positive, to compare Kinder 1 to the other scales with three measurements, we assumed only one positive response as “moderate risk”, all negative responses as “low risk”. Thus, Kinder 1 shows no cases at high risk, 83.02% moderate risk, and 16.98% low risk. All the scales show that the moderate-high risk increases with age. MEDFRAT and Morse have concordant percentages for young (13.6%), elderly (61.2%), and long-lived (66.6%) people. Kinder 1, 59%, 96.7%, and 100%, respectively.

Conclusions

The comparison between scales shows inhomogeneity in identifying the level of risk. MEDFRAT and Morse appear more reliable and consistent.

Key messages

An appropriate assessment scale is important to identify the fall risk level. Identifying accurate fall risk levels allows for implementing specific prevention actions.

Meningiomas of the Internal Auditory Canal

OBJECTIVE

Identify and define specific preoperative and postoperative characteristics of intracanalicular meningiomas (ICMs) in order to improve their diagnosis and management, and to differentiate them from intrameatal vestibular schwannomas (IMVSs).

METHODS

Preoperative symptomatology, magnetic resonance imaging (MRI), and postoperative outcomes of 28 ICMs were analyzed. The results were compared to the literature and IMVSs treated by our group.

RESULTS

Anacusis and progressive hearing loss were more frequent in the present population than the cases reviewed (P = .0064 and P = .0001, respectively). Hearing loss affected more than 90% of the patients, with anacusis in 32.1% of the cases. Facial palsy affected 17.9% of the patients. In comparison to IMVSs, preoperative anacusis was more associated to meningiomas (P = .0037), and the facial nerve was more compromised in ICMs than IMVSs, both preoperatively (P = .0011) and at follow-up (P < .0001). According to a re-evaluation of preoperative MRIs and comparison with IMVSs, linear tumor borders, and linear morphology along the internal auditory canal wall, but not the presence of a dural tail, were significantly more present in ICMs (P = .0035, P = .0004, P = .1963, respectively). These characteristics could have led to a correct preoperative diagnosis in 61% of our cases.

CONCLUSION

Contrariwise to IMVSs, the frequent preoperative anacusis and facial palsy demonstrate the more aggressive nature of ICMs, which also carry a higher risk of postoperative facial palsy and difficulty to preserve hearing. An attentive evaluation of imaging should ease diagnosis, and asymptomatic or stable ICMs should be enrolled in a wait-and-scan protocol.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E413-E419, 2021.

The effect of superior canal dehiscence size and location on audiometric measurements, vestibular-evoked myogenic potentials and video-head impulse testing

PURPOSE

To correlate objective measures of audio-vestibular function with superior canal dehiscence (SCD) size and location in ears with SCD and compare results with literature.

METHODS

We retrospectively evaluated 242 patients exhibiting SCD and/or extremely thinned bone overlying superior canals (SC) on CT scans and selected 73 SCD patients (95 ears with SCD). Data concerning audiometry, impedance audiometry, video-head impulse test (vHIT), cervical vestibular-evoked myogenic potentials (cVEMPs) and ocular VEMPs (oVEMPs) to air- (AC) and bone-conducted (BC) stimuli were collected for each pathologic ear and correlated with dehiscence size and location.

RESULTS

AC pure-tone average (PTA) (p = 0.013), low-frequency air-bone gap (ABG) (p  < 0.001), AC cVEMPs amplitude (p = 0.002), BC cVEMPs amplitude (p < 0.001) and both AC and BC oVEMPs amplitude (p < 0.001) positively correlated with increasing SCD size. An inverse relationship between dehiscence length and both AC cVEMPs and oVEMPs thresholds (p < 0.001) and SC vestibulo-ocular reflex (VOR) gain (p < 0.001) was observed. Dehiscences at the arcuate eminence (AE) exhibited lower SC VOR gains compared to SCD along the ampullary arm (p = 0.008) and less impaired BC thresholds than dehiscences at the superior petrosal sinus (p = 0.04).

CONCLUSION

We confirmed that SCD size affects AC PTA, ABG and both amplitudes and thresholds of cVEMPs and oVEMPs. We also described a tendency for SC function to impair with increasing SCD size and when dehiscence is located at the AE. The latter data may be explained either by a spontaneous canal plugging exerted by middle fossa dura or by a dissipation through the dehiscence of mechanical energy conveyed to the endolymph during high-frequency impulses.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

(Ab)use of Health Claims in Websites: The Case of Italian Bottled Waters

The massive use of web marketing makes the monitoring of nutrition and health claims used in advertising campaigns much more difficult. The present study aimed at reviewing the website content for bottled waters produced in Italy to assess (i) if nutrition and health claims are reported, (ii) what types of nutrition and health claims are reported most frequently, and (iii) if the nutrition and health claims could be considered appropriate according to the current regulation in the field. A review of the website content of the 253 bottled waters produced in Italy and reported in the annual report of Bevitalia 2016–2017 was conducted. For each brand, indications related to the preventive, curative or therapeutic properties of the water reported were examined. Bottled waters that included potentially misleading information apparently not consistent with the European Directive on the exploitation and marketing of natural mineral waters were identified. Forty bottled waters with uncertain website content were identified. The information reported in the websites referred most often to beneficial effects for urinary tract and cardiovascular systems. Present results highlight, using the bottled water case study, that website content sometimes happens to deliver misleading information to consumers, also thanks to uncertain regulation in this sensitive field.

Superior canal dehiscence with tegmen defect revealed by otoscopy: Video clip demonstration of pulsatile tympanic membrane

Superior canal dehiscence is a pathologic condition of the otic capsule acting as aberrant window of the inner ear. It results in reduction of inner ear impedance and in abnormal exposure of the labyrinthine neuroepithelium to the action of the surrounding structures. The sum of these phenomena leads to the onset of typical cochleo-vestibular symptoms and signs. Among them, pulsatile tinnitus has been attributed to a direct transmission of intracranial vascular activities to labyrinthine fluids. We present the first video-otoscopic documentation of spontaneous pulse-synchronous movements of the tympanic membrane in two patients with superior canal dehiscence. Pulsating eardrum may represent an additional sign of third-mobile window lesion.

Surgical Strategy and Facial Nerve Outcomes in Petrous Bone Cholesteatoma

Objective: To review the classification and management of petrous bone cholesteatomas (PBCs) at our center and the outcomes of facial nerve (FN) management in these lesions. Methods: This was a retrospective study. The setting was a quaternary referral center for skull base pathology in Italy. A total of 200 patients with 201 PBCs were included in the study. All patients diagnosed radiologically with PBCs were classified according to the Sanna classification. All patients were surgically treated and followed up with radiology. The main outcome measures - classification of PBCs, the surgical approach used, disease control, and FN outcomes - were analyzed. Results: Supralabyrinthine PBCs were the most common type with 92 cases (45.8%) followed by the massive PBCs with 72 cases (35.8%). Preservation of preoperative FN function was highest in the infralabyrinthine (72.2%) and infralabyrinthine-apical (73.3%) types. The transotic approach was used in 66 cases (32.8%) in this series. The modified transcochlear approach type A was applied in 55 cases (27.3%). Active management of the nerve (rerouting, anastomosis, or grafting) was required in 53 cases (26.4%). Postoperatively, of the 116 cases with FN House-Brackmann grade I and II, 107 cases (92.2%) retained the same grade or improved. Recurrence was seen in 7 cases (3.5%). The mean duration of follow-up was 6.3 years. Conclusions: Radical disease clearance must take precedence over hearing and FN preservation in PBCs. Active FN management, including rerouting, end-to-end anastomosis, and cable nerve grafting, routinely come to play in the surgical management of PBCs, and the postoperative FN results after such interventions can be satisfactory in most cases.

3,4-Dihydro-2-Alkoxy-6-Benzyl-4-Oxopyrimidines (DABOs): A New Class of Specific Inhibitors of Human Immunodeficiency Virus Type 1

A series of novel 3,4-dihydro-6-benzyl-4-oxopyrimidines substituted at both the C-5 and the C-2 positions were synthesized as potential anti-HIV agents. Preparation of the title compounds was achieved by condensation of O-methylisourea with methyl 2-alkyl-4-phenylacetylacetate and subsequent displacement of the methoxy group by reaction with a series of linear, ramified and cyclic alkoxy groups containing from three to six carbon units. Methyl 2-alkyl-4-phenylacetylacetates were prepared by alkylation of methyl 4-phenylacetylacetate, which was obtained starting from Meldrum's acid and phenacetyl chloride. Acid hydrolysis of 3,4-dihydro-6-benzyl-2-methoxy-4-oxopyrimidines furnished the corresponding 1,2,3,4-tetrahydro-6-benzyl-2,4-dioxopyrimidines. In acutely infected MT-4 cells, compounds 3e, 3o, 3q and 3r showed an anti-HIV-1 activity as potent and/or selective as HEPT and ddl. Unlike HEPT, the replacement of a methyl for an hydrogen atom at position C-5 of 3,4-dihydro-2-alkoxy-6-benzyl-4-oxopyrimidines (DABOs) did not abolish the antiviral activity, as well as the substitution of the C-5 methyl for an ethyl group did not increase the potency. However, similarly to HEPT and its derivatives, DABOs targeted the HIV-1 reverse transcriptase and neither inhibited the multiplication of HIV-2 in acutely infected MT-4 cells, nor that of HIV-1 in chronically infected H9/IIIB cells.

Goat casein genotypes are associated with milk production traits in the Sarda breed

The aim of the current work was to analyze, in the Sarda breed goat, genetic polymorphism within the casein genes and to assess their influence on milk traits. Genetic variants at the CSN1S1, CSN2, CSN1S2 and CSN3 gene loci were investigated using PCR-based methods, cloning and sequencing. Strong alleles prevailed at the CSN1S1 gene locus and defective alleles also were revealed. Null alleles were evidenced at each calcium-sensitive gene locus. At the CSN3 gene locus, we observed a prevalence of the CSN3 A and B alleles; the occurrence of rare alleles such as CSN3 B'', C, C', D, E and M; and the CSN3 S allele (GenBank KF644565) described here for the first time in Capra hircus. Statistical analysis showed that all genes, except CSN3, significantly influenced milk traits. The CSN1S1 BB and AB genotypes were associated with the highest percentages of protein (4.41 and 4.40 respectively) and fat (5.26 and 5.34 respectively) (P < 0.001). A relevant finding was that CSN2 and CSN1S2 genotypes affected milk protein content and yield. The polymorphism of the CSN2 gene affected milk protein percentage with the highest values recorded in the CSN2 AA goats (4.35, at P < 0.001). The CSN1S2 AC goats provided the highest fat (51.02 g/day) and protein (41.42 g/day) (P < 0.01) production. This information can be incorporated into selection schemes for the Sarda breed goat.

CD4⁺ but not CD8⁺ T cells revert the impaired emotional behavior of immunocompromised RAG-1-deficient mice

An imbalanced immune system has long been known to influence a variety of mood disorders including anxiety, obsessive-compulsive disorders and depression. In this study, we sought to model the impact of an immunocompromised state on these emotional behaviors using RAG-1⁻/⁻ mice, which lack T and B cells. We also investigated the relative contribution of CD4⁺ or CD8⁺ T cells to these manifestations using RAG-1⁻/⁻/OT-II and RAG-1⁻/⁻/OT-I transgenic mice, respectively. Our results show that RAG-1⁻/⁻ mice present a significant increase in digging and marble-burying activities compared with wild-type mice. Surprisingly, these anxiety-like behaviors were significantly reverted in RAG-1⁻/⁻/OT-II but not RAG-1⁻/⁻/OT-I transgenic mice. Immunodepletion experiments with anti-CD4 or anti-CD8 in C57/BL6 mice or repopulation studies in RAG-1⁻/⁻ mice did not reproduce these findings. Microarray analysis of the brain of RAG-1⁻/⁻ and RAG-1⁻/⁻/OT-II mice revealed a significantly different gene fingerprint, with the latter being more similar to wild-type mice than the former. Further analysis revealed nine main signaling pathways as being significantly modulated in RAG-1⁻/⁻ compared with wild-type mice. Taken together, these results suggest that life-long rather than transient immunodeficient conditions influence the emotional behaviors in mice. Most interestingly, these effects seem to correlate with a specific absence of CD4⁺ rather than CD8⁺ T cells. Validation of these findings in man might provide new clues on the mechanism by which early life immune modulation might impact mood response in adults and provide a further link between immune and emotional well-being.

Evidence for a role of a dopamine/5-HT6 receptor interaction in cocaine reinforcement

The putative 5-HT6 receptor agonist ST1936 has been shown to increase extracellular dopamine (DA) in the n.accumbens (NAc) shell and in the medial prefrontal cortex (PFCX). These observations suggest that 5-HT6 receptors modulate DA transmission in mesolimbic and mesocortical terminal DA areas. To investigate the behavioral counterpart of this interaction we studied in rats 1) the ability of ST1936 to maintain i.v. self-administration in fixed ratio (FR) and progressive ratio (PR) schedules of reinforcement; 2) the effect of 5-HT6 receptor blockade on cocaine stimulated overflow of DA in dialysates from the PFCX and from the NAc shell and on cocaine i.v. self-administration. ST1936 was i.v. self-administered at unitary doses of 0.5-1 mg/kg on an FR1 and PR schedule of reinforcement, with breaking point of about 4. Pretreatment with the 5-HT6 antagonist SB271046 reduced by about 80% responding for ST1936. SB271046 also reduced cocaine-induced increase of dialysate DA in the NAc shell but not in the PFCX and impaired i.v. cocaine self-administration. These observations indicate that ST1936 behaves as a weak reinforcer and suggest that 5-HT6 receptors play a role in cocaine reinforcement via their facilitatory interaction with DA projections to the NAc shell. This novel 5-HT/DA interaction might provide the basis for a new pharmacotherapeutic strategy of cocaine addiction.

Ocular vestibular evoked myogenic potentials in patients with acoustic neuroma

To assess the usefulness of vestibular testing in patients with acoustic neuroma, considering two main aspects: to compare diagnostic sensitivity of the current vestibular tests, especially considering ocular vestibular evoked myogenic potentials (OVEMPs) and to identify pre-operative localization of the tumor (inferior vestibular nerve vs. superior vestibular nerve) only with the help of vestibular electrophysiological data. Twenty-six patients with unilateral acoustic neuroma (mainly intracanalicular type) were studied with a full audio-vestibular test battery (pure tone and speech audiometry, caloric bithermal test, vibration-induced nystagmus test (VIN), cervical and OVEMPs). 18 patients (69 %) showed abnormal caloric responses. 12 patients (46.2 %) showed a pattern of VIN test suggestive of vestibular asymmetry. 16 patients (61.5 %) showed abnormal OVEMPs (12 only to AC, 4 both to AC and BC). 10 patients (38.5 %) showed abnormal cervical vestibular evoked myogenic potentials (5 both to AC and BC, 5 only to AC). In one case, results of vestibular evoked potentials and caloric test were confirmed by intra-operative and post-operative findings. Results of electrophysiological tests in AN patients could be helpful for planning the proper surgical approach, considering that sensitivity of every exam is quite low in intracanalicular lesion; clinical data allow a better interpretation of vestibular evoked myogenic potentials.

BRCA1 and BRCA2 germline mutations in Sardinian breast cancer families

20118

Background: Germline alterations in the BRCA1 and BRCA2 genes highly predispose to breast and ovarian cancer. In families with BRCA1/2 mutations, identification of mutation carriers is clinically rilevant in view of the options for surveillance and prevention. The general aim of the present research is to contribute to the molecular epidemiology of BRCA1/2 genes in the italian region of Sardinia as a prerequisite for a prevention program based on DNA analysis. Methods: Fifty-two of 172 patients diagnosed with primary invasive breast carcinomas (n = 150) or ovarian cancer (n = 18) and 4 male with breast cancer referring to our departments between 2003 and 2005, had a positive family history for breast and/or ovarian cancer and were selected for BRCA1/2 mutation screening by denaturing high-performance liquid chromatography and DNA sequencing. Onehundred DNAs from healthy women originating from the same geographical area were used as population controls. Results: We identified 7 BRCA sequence alterations: 3 were already described polymorphisms while 4 novel BRCA variants were found in 11 out of 52 (21%) probands. The BRCA23951del3insAT is a novel deleterious mutation which leads to protein truncation at codon 1258 and co-occurred with the missense BRCA2S2546P in 6 probands originating from the same village and in none of the controls. Segregation analysis suggested the cis-position of the two mutations. All mutation carriers shared a common disease-associated BRCA2 haplotype indicating the presence of a founder effect. The BRCA2N272I was first observed in our population and was found in 3 unrelated probands and in none of 200 control chromosomes. The missense BRCA1E1352K mutation was present in 3 patients from two unrelated families with breast and ovarian cancer cases in three generations. Conclusions: In the present study, BRCA2 are more recurrent than BRCA1 mutations as reported for the northern part of the island. Our findings provide new epidemiological data that may be useful in defining the prevalence, mutational spectrum and penetrance of BRCA1/2 in the genetically homogeneous population of Sardinia. A comprehensive map of the BRCA mutations may facilitate screening/testing for inherited risk of breast cancer.

No significant financial relationships to disclose.

Genetic analysis of the 2q33 region containing CD28-CTLA4-ICOS genes: association with non-Hodgkin's lymphoma

There is strong evidence that altered immunological function entails an increased risk of lymphoma, although the current knowledge of aetiological factors for lymphomas is limited. The CTLA4 gene encodes a receptor that provides a negative signal to the T-cell once an immune response is initiated and completed. We analysed the 2q33 chromosomal region harbouring CD28, CTLA4 and ICOS genes, which are closely linked and have related functions in immune regulation, for association in 100 non-Hodgkin's lymphoma (NHL) patients and in 128 healthy controls; both groups originated from Sardinia. There was a strong association of the CTLA4 49A and the 3'-untranslated region (AT)(82) alleles with NHL [odds ratio (OR) = 2, 95% confidence interval (CI) = 1.2-3.2, and OR = 1.6, 95% CI = 1.1-2.4 respectively]. CTLA4-318C:49A:(AT)(82) was the most represented haplotype in the studied population and was associated with NHL (P = 0.0029, OR = 1.76, 95% CI = 1.2-2.5). Strong linkage disequilibrium was detected between CD28, CTLA4 and ICOS and a 'common' haplotype was found very frequently among NHLs. However, no independent association between CD28, ICOS, D2S72 markers and NHL was observed. Our findings enable CTLA4 from adjacent functionally related genes as the true causative risk gene for NHL susceptibility at least in Sardinian patients.

Differential activation of dopamine release in the nucleus accumbens core and shell after acute or repeated amphetamine injections: A comparative study in the Roman high- and low-avoidance rat lines

The selectively bred Roman high- and low-avoidance rats differ in emotionality and responsiveness to the motor effects of acute and repeated psychostimulant administration. These lines also show drastic differences in the neurochemical responses of their mesolimbic dopamine systems to addictive drugs. The nucleus accumbens is critically involved in the locomotor activation produced by psychostimulants and in the augmentation of this effect observed upon repeated drug administration (i.e. behavioral sensitization), although there is not a general consensus as to whether the nucleus accumbens-core or the nucleus accumbens-shell is preferentially involved in such alterations. This study was designed to evaluate the effects of acute amphetamine (0.20 mg/kg, s.c.) on dopamine output in the nucleus accumbens-shell and nucleus accumbens-core of the Roman lines under basal conditions (i.e. naïve rats) and after the repeated administration of amphetamine (1 mg/kg, s.c. x 10 days) or saline. We show that (1) in naïve rats, amphetamine caused a larger increment in dopamine output in the nucleus accumbens-shell vs the nucleus accumbens-core only in the Roman high-avoidance line; (2) repeated amphetamine elicits behavioral sensitization in Roman high-avoidance, but not Roman low-avoidance, rats; (3) in sensitized Roman high-avoidance rats, amphetamine provokes a larger increment in dopamine output in the nucleus accumbens-core, and an attenuated dopaminergic response in the nucleus accumbens-shell, as compared with Roman high-avoidance rats repeatedly treated with saline; and (4) such neurochemical changes are not observed in the mesoaccumbens dopaminergic system of the sensitization-resistant Roman low-avoidance line. We propose that (1) Roman high-avoidance and Roman low-avoidance rats differ in the vulnerability to develop psychostimulant sensitization, (2) the nucleus accumbens-core and nucleus accumbens-shell subserve distinct functional roles in this phenomenon, and (3) comparative studies in the Roman lines may provide insight into the influence of neural substrates and genetic background on the individual vulnerability to addiction.

Differential neurochemical properties of central serotonergic transmission in Roman high- and low-avoidance rats

The selective breeding of Roman high- (RHA/Verh) and low-avoidance (RLA/Verh) rats for rapid versus poor acquisition of active avoidant behaviour has produced two behavioural phenotypes with different performances in a variety of animal models of anxiety, in which RLA/Verh rats are consistently more fearful than RHA/Verh rats. In addition, these two lines display different functional properties of brain neurotransmitters like serotonin (5-HT), known to be involved in the expression of anxiety- and depression-related behaviours. Therefore, we used brain microdialysis and [3H]-citalopram binding autoradiography to characterize further the neurochemical properties of 5-HTergic transmission in the two lines. No significant line-related differences were detected in the basal 5-HT output in the frontoparietal cortex (FPCx). In contrast, the increase in the cortical 5-HT output elicited by the systemic administration or the local application, via reverse dialysis, of chlorimipramine and fluoxetine was more robust in RHA/Verh than in RLA/Verh rats. Moreover, the binding signal of [3H]-citalopram to 5-HT re-uptake sites was more intense in the FPCx of RHA/Verh rats than in their RLA/Verh counterparts. These findings suggest that the functional tone of the 5-HTergic projection to the FPCx is stronger in the RHA/Verh line relative to the RLA/Verh line. It is proposed that RLA/Verh rats may be used as a model with heuristic value for studying the role of 5-HTergic transmission in anxiety and in the anxiolytic effects of monoamine re-uptake inhibitors.