Effects of familiar music exposure on deliberate retrieval of remote episodic and semantic memories in healthy aging adults

Familiar music facilitates memory retrieval in adults with dementia. However, mechanisms behind this effect, and its generality, are unclear because of a lack of parallel work in healthy aging. Exposure to familiar music enhances spontaneous recall of memories directly cued by the music, but it is unknown whether such effects extend to deliberate recall more generally - e.g., to memories not directly linked to the music being played. It is also unclear whether familiar music boosts recall of specific episodes versus more generalised semantic memories, or whether effects are driven by domain-general mechanisms (e.g., improved mood). In a registered report study, we examined effects of familiar music on deliberate recall in healthy adults ages 65-80 years (N = 75) by presenting familiar music from earlier in life, unfamiliar music, and non-musical audio clips across three sessions. After each clip, we assessed free recall of remote memories for pre-selected events. Contrary to our hypotheses, we found no effects of music exposure on recall of prompted events, though familiar music evoked spontaneous memories most often. These results suggest that effects of familiar music on recall may be limited to memories specifically evoked in response to the music (Preprint and registered report protocol at https://osf.io/kjnwd/).

129 RE-THINKING THE MEMORY CONSENSUS MEETING: A QUALITY IMPROVEMENT INITIATIVE

Background

As part of our memory clinic service, weekly consensus meetings are held to allow for multidisciplinary diagnostic evaluation of new cases. As part of a local Quality Improvement (QI) initiative, we reviewed how this meeting could be streamlined to maximise efficiency and improve diagnostic accuracy in light of increasing referrals and patient complexity. Here we describe the development and initial implementation of this QI project.

Methods

A structured QI approach was taken to develop SMART (Specific, Measurable, Achievable, Realistic, Timely) goals. All professional stakeholders (from disciplines including geriatric medicine, neurology and psychiatry of later life) who attend the weekly consensus meeting were surveyed anonymously with a response rate of 80% (n=8). Information was gathered on areas that worked well, areas that needed improvement and suggestions for meeting enhancement. In addition, participants were asked at a single meeting to subjectively rate the complexity of eleven cases presented into the following categories: low, medium and high. Data were collated and presented to the memory clinic staff for further refinement.

Results

Four key actions were identified for implementation: formal allocation of a meeting chair, improvement of access to imaging from outside hospitals, revision of current proforma to streamline case discussions, and proposal to discuss patients in order of new assessment, return assessment and review of significant results. During the rating of case complexity, there was substantial variation among respondents.

Conclusion

This initial phase has been used to develop SMART goals to improve the consensus meeting structure. We identified that patient complexity would be an inefficient method to order case discussion. Implementation of action steps are ongoing, with positive feedback from staff to date.

Supporting sAFE and GradUAl ReDuctIon of loNG-term BenzodiaZepine Receptor Agonist uSe: development of the SAFEGUARDING-BZRAs toolkit using a co-design approach

Introduction

Long-term benzodiazepine receptor agonist (BZRA) use (>3 months) persists worldwide and poses risks of harm. Effective interventions are needed to address this issue.

Aim

To develop an intervention to support discontinuation of long-term benzodiazepine receptor agonist (BZRA) use.

Methods

The intervention development process built on previous qualitative work that used the Theoretical Domains Framework (TDF) to explore perceived barriers and facilitators to discontinuing long-term BZRA use (1). A co-design approach was used whereby lay individuals and professionals worked as equals during the research process based on principles of authentic participation and collaboration (2). The co-design team included five ‘experts by lived experience’ with experience of long-term BZRA use who previously provided input on other related work as patient and public involvement representatives or responded to an expression of interest call on social media. Two online co-design team meetings were held. During the first meeting, a summary of previous findings was presented together with a long-list of behaviour change techniques (BCTs) generated using established mapping matrices in which BCTs were reliably allocated to the TDF. Each team member independently documented their decision as to whether each BCT should be included in a short-list for potential inclusion in the final intervention using online polling software. The a priori decision rule was that 70% of team members had to agree regarding the inclusion/exclusion of a BCT. All other BCTs were then discussed at a follow-up meeting. A finalised list of BCTs for inclusion in the intervention was agreed at the second meeting using a consensus-based approach involving the same decision rule. Potential ways in which BCTs could be operationalised were then discussed.

Results

Thirty BCTs were discussed and six BCTs were excluded. For example, team members recommended avoiding ‘Social comparison’ as individual circumstances and experiences of discontinuation and associated withdrawal symptoms are unique and not directly comparable. Given the number of included BCTs, the co-design team recommended presenting them as a toolkit. The SAFEGUARDING-BZRAs (Supporting sAFE and GradUAl ReDuctIon of loNG-term BenzodiaZepine Receptor Agonist uSe) toolkit comprises 24 BCTs: ‘Goal setting (behaviour)’, ‘Review behaviour goal(s)’, ‘Review outcome goal(s)’, ‘Feedback on behaviour’, ‘Self-monitoring of behaviour’, ‘Social support (practical)’, ‘Social support (emotional)’, ‘Information about health consequences’, ‘Monitoring of emotional consequences’, ‘Information about emotional consequences’, ‘Prompts/cues’, ‘Habit reversal’, ‘Graded tasks’, ‘Pros and cons’, ‘Comparative imagining of future outcomes’, ‘Social reward’, ‘Self-reward’, ‘Reduce negative emotions’, ‘Distraction’, ‘Adding objects to the environment’, ‘Body changes’, ‘Verbal persuasion about capability’, ‘Focus on past success’ and ‘Credible source’. The toolkit includes recommendations targeted at primary care-based clinicians for operationalising each BCT to support BZRA discontinuation.

Conclusion

The SAFEGUARDING-BZRAs toolkit has been developed using a systematic, theory-based approach that addresses identified limitations of previous research (e.g. lack of detailed intervention description). In terms of limitations, it is possible that a different group of individuals may have developed a different type of intervention. To overcome this, a priori decision rules were used for decision making. Further research is needed to assess the toolkit’s usability and acceptability by service users and clinicians.

References

(1) Lynch et al. Health Expect. [in press] DOI: 10.1111/hex.13392.

(2) O’Donnell et al. BMC Health Serv Res. 2019;19(1):797

CD8 encephalitis with CSF EBV viraemia and HIV drug resistance, a case series

Introduction

CD8 encephalitis is a relatively recently described condition in the setting of HIV infection. It is becoming increasingly recognised in recent years though is still likely underdiagnosed.

Methods

We present three cases of encephalitis in HIV-positive black African females initially presenting with neurological pathology. Two cases concern recent presentations of patients attending HIV services at a large tertiary referral hospital and the third case involves a retrospective analysis of an archived case.

Results and discussion

MRI brain demonstrated periventricular white matter changes in 2 cases and a cerebellar lesion in the third case. CSF examination revealed lymphocytosis and elevated protein levels. CSF HIV viral load analysis showed viral escape along with new antiretroviral drug resistance mutations. CSF flow cytometry studies demonstrated a reversed CD4:CD8 ratio with a high CD8⁺ cells percentage. All patients had EBV DNA detected in their CSF. Brain biopsy in two patients confirmed CD8 encephalitis and also revealed isolated cells demonstrating EBV positivity by in-situ hybridization using EBER (Epstein–Barr virus-encoded small RNAs). Treatment with steroids and ART optimisation led to significant clinical and radiological improvements in all cases.

Discussion

CD8 encephalitis should be considered as a cause of neurological symptoms and confusion in the HIV-positive patient, particularly if poor ART adherence or viral resistance are suspected. Brain biopsy should be considered in HIV-positive patients with encephalopathy of uncertain cause. Early treatment with high-dose corticosteroids when suspecting this diagnosis is essential for a favourable outcome. The prognosis is variable but can be favourable even following severe encephalopathy. The presence of new INSTI mutations in the CSF but absent peripherally in two INSTI-era patients is a novel finding for this case series in the context of CD8 encephalitis. The role played by EBV in this disease remains unclear and warrants further investigation.

A Risk Score Model for Locoregional Recurrence Following Upfront Surgery for Pancreatic Adenocarcinoma: Implications for Adjuvant Therapy

AIMS

The aims of the study were to identify predictors of locoregional failure (LRF) following surgery for pancreatic adenocarcinoma, develop a prediction risk score model of LRF and evaluate the impact of postoperative radiation therapy (PORT) on LRF.

MATERIALS AND METHODS

A retrospective review was conducted on patients with stages I-III pancreatic adenocarcinoma who underwent surgery at our institution (2005-2016). Univariable and then multivariable analyses were used to evaluate clinicopathological factors associated with LRF for patients who did not receive PORT. The risk score of LRF was calculated based on the sum of coefficients of the predictors of LRF. The model was applied to the entire cohort to evaluate the impact of PORT on the high- and low-risk groups for LRF.

RESULTS

In total, 467 patients were identified (median follow-up 22 months). Among patients who did not receive PORT (n = 440), predictors of LRF were pN+, involved or close ≤1 mm margin(s), moderately and poorly differentiated tumour grade and lymphovascular invasion. After adding patients who received PORT, the 2-year LRF in the high-risk group was 57% for patients who did not receive PORT (n = 242) and 32% among patients who received PORT (n = 22), with an absolute benefit to LRF of 25% (95% confidence interval 5-52%, P = 0.07). The 2-year overall survival for the high-versus the low-risk group was 36% versus 67% (P < 0.001).

CONCLUSION

This risk group classification could be used to identify pancreatic adenocarcinoma patients with higher risk of LRF who may benefit from PORT. However, validation and prospective evaluation are warranted.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Modelling the impact of a national scale-up of interventions on hepatitis C virus transmission among people who inject drugs in Scotland

BACKGROUND AND AIMS

To reduce hepatitis C virus (HCV) transmission among people who inject drugs (PWID), Scottish Government-funded national strategies, launched in 2008, promoted scaling-up opioid substitution therapy (OST) and needle and syringe provision (NSP), with some increases in HCV treatment. We test whether observed decreases in HCV incidence post-2008 can be attributed to this intervention scale-up.

DESIGN

A dynamic HCV transmission model among PWID incorporating intervention scale-up and observed decreases in behavioural risk, calibrated to Scottish HCV prevalence and incidence data for 2008/09.

SETTING

Scotland, UK.

PARTICIPANTS

PWID.

MEASUREMENTS

Model projections from 2008 to 2015 were compared with data to test whether they were consistent with observed decreases in HCV incidence among PWID while incorporating the observed intervention scale-up, and to determine the impact of scaling-up interventions on incidence.

FINDINGS

Without fitting to epidemiological data post-2008/09, the model incorporating observed intervention scale-up agreed with observed decreases in HCV incidence among PWID between 2008 and 2015, suggesting that HCV incidence decreased by 61.3% [95% credibility interval (CrI) = 45.1-75.3%] from 14.2/100 person-years (py) (9.0-20.7) to 5.5/100 py (2.9-9.2). On average, each model fit lay within 84% (10.1/12) of the confidence bounds for the 12 incidence data points against which the model was compared. We estimate that scale-up of interventions (OST + NSP + HCV treatment) and decreases in high-risk behaviour from 2008 to 2015 resulted in a 33.9% (23.8-44.6%) decrease in incidence, with the remainder [27.4% (17.6-37.0%)] explained by historical changes in OST + NSP coverage and risk pre-2008. Projections suggest that scaling-up of all interventions post-2008 averted 1492 (657-2646) infections over 7 years, with 1016 (308-1996), 404 (150-836) and 72 (27-137) due to scale-up of OST + NSP, decreases in high-risk behaviour and HCV treatment, respectively.

CONCLUSIONS

Most of the decline in hepatitis C virus (HCV) incidence in Scotland between 2008 and 2015 appears to be attributable to intervention scale-up (opioid substitution therapy and needle and syringe provision) due to government strategies on HCV and drugs.

Intravascular large B-cell lymphoma presenting clinically as rapidly progressive dementia

BACKGROUND

In patients presenting with rapidly progressive dementia, prion disease may enter the differential diagnosis. The commonest malignancies masquerading as prion disease are primary CNS lymphoma and intravascular large B-cell lymphoma, both rare and difficult to diagnose without brain biopsy.

CASE PRESENTATION

This 82-year-old lady with a past history of hypertension, presented with rapidly progressive cognitive impairment and ataxia. The possibility of sCJD was raised. Brain biopsy was carried out. Western blot for prion protein was negative. Brain biopsy showed intravascular large B-cell lymphoma. She died shortly afterwards.

CONCLUSION

The clinical presentation of intravascular large B-cell lymphoma is diverse. Patients may present as in this case with dementia, seizures, and myoclonus leading to a clinical diagnosis of sCJD. The diagnosis here was made at biopsy but is made at autopsy in over 50% of cases.

Chronic traumatic encephalopathy: a potential late and under recognized consequence of rugby union?

The association between exposure to head injury and increased risk of neurodegenerative disease, specifically chronic traumatic encephalopathy (CTE), is widely recognized. Historically, this was largely considered a phenomenon restricted to boxers, with more recent case series identifying further 'high risk' individuals, such as former American footballers, or military personnel. However, in all cases thus far reported, it is clear that it is the exposure to head injury which is associated with increased dementia risk, and not the circumstances or environment of exposure. As such, there is considerable potential for under-recognition of CTE in patients presenting with neurodegenerative disease, particularly where head injury exposure might have been historical and through sport. This article reviews current understanding of CTE and, via an illustrative case in rugby union, highlights the value of a detailed history on head injury and also draws attention to imaging studies in assessing patients with neurodegenerative disease.

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10(-1) mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Risk of transmission associated with sharing drug injecting paraphernalia: analysis of recent hepatitis C virus (HCV) infection using cross-sectional survey data

Sharing injecting paraphernalia (containers, filters and water) poses a risk of transmitting the hepatitis C virus (HCV). The prevalence of, and risk of HCV from, such behaviour has not been extensively reported in Europe. People who inject drugs (PWID) were recruited in cross-sectional surveys from services providing sterile injecting equipment across Scotland between 2008 and 2010. Participants completed a questionnaire and provided a blood spot for anonymous testing. Logistic regression was used to examine the association between recent HCV infection (anti-HCV negative and HCV-RNA positive) and self-reported measures of injecting equipment sharing in the 6 months preceding interview. Twelve per cent of the sample reported sharing needles/syringes, and 40% reported sharing paraphernalia in the previous 6 months. The adjusted odds ratios (AOR) for sharing needles/syringes (+/- paraphernalia), and sharing only paraphernalia in the last 6 months were 6.7 (95% CI 2.6-17.1) and 3.0 (95% CI 1.2-7.5), respectively. Among those who reported not sharing needles/syringes, sharing containers and filters were both significantly associated with recent HCV infection (AOR 3.1, 95% CI 1.3-7.8 and 3.1, 95% CI 1.3-7.5, respectively); sharing water was not. We present the first study to apply a cross-sectional approach to the analysis of the association between sharing paraphernalia and incident HCV infection and demonstrate consistent results with previous longitudinal studies. The prevalence of paraphernalia sharing in our study population is high, representing significant potential for HCV transmission.

Interference between competing pathways in atomic harmonic generation

We investigate the influence of the autoionizing 3s3p(6)nℓ resonances on the fifth harmonic generated by 200-240 nm laser fields interacting with Ar. To determine the influence of a multielectron response we develop the capability within time-dependent R-matrix theory to determine the harmonic spectra generated. The fifth harmonic is affected by interference between the response of a 3s electron and the response of a 3p electron, as demonstrated by the asymmetric profiles in the harmonic yields as functions of wavelength.

Compliance to oseltamivir and subsequent occurrence of self-reported adverse drug reactions among nursery and primary school children following exposure to Influenza A(H1N1)v

During the containment phase of Influenza A(H1N1)v, a nursery, a primary school and an afterschool club were closed after two pupils were found confirmed cases. Classmates were prescribed postexposure oseltamivir. Compliance was expected to be low. The objective of this study was to assess compliance, the number of children developing adverse drug reactions (ADRs) and the reasons for stopping the course prematurely. We conducted a survey among parents of all classmates of the two cases. Parents were asked about compliance and adverse drug events in a questionnaire or underwent a telephone interview. Response was high, 88%. Seventy-nine percent of the children were compliant to the prescribed dose of oseltamivir. One in four children experienced at least one ADR. Children who took a higher daily dose (treatment dose) developed significantly more often ADRs. No children developed Influenza A(H1N1)v. We found that a high overall compliance to prescribed oseltamivir can be achieved in very young children (1-11 years). The proportion of children developing ADRs was much lower than described in two other recent UK investigations. Possibly, this is related to the socioeconomic status of the population under investigation.

Pulmonary hypertension in children and adolescents with sickle cell disease

The prevalence of pulmonary hypertension (PHTN) in the pediatric sickle cell disease (SCD) population is not known despite its high prevalence in adult patients. Our hypothesis was that increased pulmonary artery pressures (PAPs) would be found in SCD children and adolescents, especially those with a history of pulmonary complications: acute chest syndrome, obstructive sleep apnea, asthma, and reactive airway disease. Fifty-two SCD children, 23 of whom had underlying pulmonary disease, were screened for PHTN, which was defined as a tricuspid regurgitant jet velocity (TRV) of at least 2.5 m/s. Twenty-four (46.15%) SCD patients had increased PAP (i.e., TRV > or =2.5 m/s), and 6 (11.5%) had significant PHTN (i.e., TRV > or =3.0 m/s). Pulmonary disease was marginally associated with PHTN (odds ratio 2.80 and confidence interval 0.88 to 8.86; p = 0.0795). As in adult SCD patients with PHTN, this complication was correlated with the degree of hemolysis as manifested by significantly higher lactate dehydrogenase and bilirubin, lower hemoglobin and hematocrit levels, and a strong association with Hb-SS phenotype. However, after statistical adjustment for age and sex, increased serum LDH was not associated with the development of PHTN. Further studies are needed to clarify the prevalence and mechanisms of PHTN in pediatric and adolescent patients with SCD.

Diversity of needle exchange provision in the UK: findings from a national survey

Needle exchanges are key to reducing transmission of bloodborne viruses (BBVs) in injecting drug users (IDUs) through the provision of sterile

Prevalence of, and risk factors for, hepatitis C virus infection among recent initiates to injecting in London and Glasgow: cross sectional analysis

Our aim was to compare the prevalence of antibody to hepatitis C virus (anti-HCV) among recently initiated injecting drug users (IDUs) in London and Glasgow, and to identify risk factors which could explain differences in prevalence between the cities. Complementary studies of community recruited IDUs who had initiated injection drug use since 1996 were conducted during 2001-2002. Data on HCV risk behaviours were gathered using structured questionnaires with identical core questions and respondents were asked to provide an oral fluid specimen which was tested anonymously for anti-HCV but was linked to the questionnaire. Sensitivities of the anti-HCV assays for oral fluid were 92-96%. Prevalence of anti-HCV was 35% (122/354) in London and 57% (207/366) in Glasgow (P < 0.001). Multifactorially, factors significantly associated with raised odds of anti-HCV positivity were increasing length of injecting career, daily injection, polydrug use, having had a needlestick injury, and having served a prison sentence. In addition lower odds of anti-HCV positivity were associated with non-injection use of crack cocaine and recruitment from drug agencies. After adjustment for these factors, the increased odds of anti-HCV associated with being a Glasgow IDU were diminished but remained significant. HCV continues to be transmitted among the IDU population of both cities at high rates despite the availability of syringe exchange and methadone maintenance. Effectiveness of harm reduction interventions may be compromised by inadequate coverage and failure to reduce sufficiently the frequency of sharing different types of injecting equipment, as well as the high background prevalence of HCV, and its high infectivity. Comprehensive action is urgently required to reduce the incidence of HCV among injectors.

Severe illness and death among injecting drug users in Scotland: a case-control study

Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 'definite' and 32 'probable' cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia.

Repetitive TMS of the motor cortex improves ipsilateral sequential simple finger movements

BACKGROUND

Disruption of cortical function can improve behavior. Motor cortex (M1) transcallosal interactions are mainly inhibitory; after unilateral damage to M1, there is increased excitability of the unaffected M1. Repetitive transcranial magnetic stimulation (rTMS) of M1 produces a temporary reduction in cortical excitability in the same M1 that outlasts the duration of the rTMS train. The authors hypothesize that reducing cortical excitability of M1 by rTMS may improve motor performance in the ipsilateral hand by releasing the contralateral M1 from transcallosal inhibition.

METHODS

Sixteen healthy volunteers participated. Using a sequential key-pressing task with the index finger, motor performance was monitored before and after rTMS (1 Hz for 10 minutes with the intensity below motor threshold) applied to the ipsilateral M1, contralateral M1, ipsilateral premotor area, or vertex (Cz).

RESULTS

rTMS of M1 shortened execution time of the motor task with the ipsilateral hand without affecting performance with the contralateral hand. This effect outlasted rTMS by at least 10 minutes, was specific for M1 stimulation, and was associated with increased intracortical excitability in the unstimulated M1.

CONCLUSIONS

The authors' results support the concept of an interhemispheric "rivalry." They demonstrate the utility of repetitive transcranial magnetic stimulation to explore the functional facilitation of the unstimulated counterpart motor cortex, presumably via suppression of activity in the stimulated motor cortex and transcallosal inhibition.

Incidence of hepatitis C virus infection and associated risk factors among Scottish prison inmates: a cohort study

To gauge the incidence of hepatitis C virus (HCV) infection and associated risk factors among inmates during their imprisonment, the authors recruited adult males in a long-stay Scottish prison into a cohort study between April 1999 and October 2000. On two occasions (at 0 and 6 months), saliva was collected for anonymous HCV antibody testing and risk behavior data were obtained through a self-administered questionnaire. The participation rate was 85% at both initial recruitment (612/719) and follow-up (375/441; 171 men were ineligible for follow-up). For inmates who reported never having injected drugs, ever having injected drugs, having injected drugs during follow-up, and having shared needles/syringes during follow-up, HCV incidences per 100 person-years of incarceration risk were 1, 12, 19, and 27, respectively. Ever having injected drugs (relative risk = 13.0, 95% confidence interval: 1.5, 114.3) and having shared needles/syringes during follow-up (relative risk = 9.0, 95% confidence interval: 1.1, 71.7) were significantly associated with HCV seroconversion. The effectiveness of existing interventions, including the provision of bleach tablets for sterilizing injection equipment, was suboptimal. The development of methadone maintenance programs in prisons and the creation of drug courts to keep offending drug injectors out of prison might help to reduce transmission in this setting.

Paradoxical cerebral embolisation

Fat embolism occurs following fractures of a long bone or arthroplasty. We investigated whether paradoxical embolisation through a venous-to-arterial circulation shunt (v-a) could lead to cerebral embolisation during elective hip or knee arthroplasty.

Transcranial Doppler ultrasound (TCD), following the intravenous injection of microbubble contrast, identified the presence of a shunt in 41 patients undergoing hip (n=20) or knee (n=21) arthroplasty. Intra-operative cerebral embolism was detected during continuous TCD monitoring. Of the 41 patients, 34 had a v-a shunt of whom 18 had an embolism and embolism only occurred in patients with a shunt (p = 0.012). Spontaneous and larger shunts were associated with a greater number of emboli (rs = 0.67 and rs = 0.71 respectively, p < 0.01). Observations in two patients with large spontaneous shunts revealed 368 and 203 emboli and unexplained post-operative confusion and pancreatitis.

Paradoxical cerebral embolisation only occurred in patients with a shunt and may explain both postoperative confusion and fat embolism syndrome following surgery.