Testing the cognitive effects of tadalafil. Neuropsychological secondary outcomes from the PASTIS trial.

Cerebral small vessel disease (SVD) is a major cause of cognitive impairment in older people. As secondary endpoints in a phase-2 randomised clinical trial, we tested the effects of single administration of a widely-used PDE5 inhibitor, tadalafil, on cognitive performance in older people with SVD. In a double-blinded, placebo-controlled, cross-over trial, participants received tadalafil (20 mg) and placebo on two visits ≥ 7 days apart (randomised to order of treatment). The Montreal Cognitive Assessment (MOCA) was administered at baseline, alongside a measure to estimate optimal intellectual ability (Test of Premorbid Function). Then, before and after treatment, a battery of neuropsychological tests was administered, assessing aspects of attention, information processing speed, working memory and executive function. Sixty-five participants were recruited and 55 completed the protocol (N = 55, age: 66.8 (8.6) years, range 52-87; 15/40 female/male). Median MOCA score was 26 (IQR: 23, 27], range 15-30). No significant treatment effects were seen in any of the neuropsychological tests. There was a trend towards improved performance on Digit Span Forward (treatment effect 0.37, C.I. 0.01, 0.72; P = 0.0521). We did not identify significant treatment effects of single-administration tadalafil on neuropsychological performance in older people with SVD. The trend observed on Digit Span Forward may help to inform future studies. Clinical trial registration: http://www.clinicaltrials.gov. Unique identifier: NCT00123456, https://eudract.ema.europa.eu. Unique identifier: 2015-001,235-20NCT00123456.

Reframing postconcussional syndrome as an interface disorder of neurology, psychiatry and psychology.

Persistent symptoms following a minor head injury can cause significant morbidity, yet the underlying mechanisms for this are poorly understood. The shortcomings of the current terminology that refer to non-specific symptom clusters is discussed. This update considers the need for a multi-dimensional approach for the heterogenous mechanisms driving persistent symptoms after mild traumatic brain injury. Relevant pathophysiology is discussed to make the case for mild traumatic brain injury to be conceptualized as an interface disorder spanning neurology, psychiatry and psychology. The relevance of pre-injury factors, psychological co-morbidities and their interaction with the injury to produce persistent symptoms are reviewed. The interplay with psychiatric diagnoses, functional and somatic symptom disorder presentations and the influence of the medicolegal process is considered. The judicious use and interpretation of investigations given the above complexity is discussed, with suggestions of how the explanation of the diagnostic formulation to the patient can be tailored, including insight into the above processes, to aid recovery. Moving beyond the one-dimensional concept of 'postconcussional syndrome' and reframing the cause of persistent symptoms following mild traumatic brain injury in a bio-psycho-socio-ecological model will hopefully improve understanding of the underlying contributory mechanistic interactions and facilitate treatment.

The PASTIS trial: Testing tadalafil for possible use in vascular cognitive impairment.

INTRODUCTION: There are few randomized clinical trials in vascular cognitive impairment (VCI). This trial tested the hypothesis that the PDE5 inhibitor tadalafil, a widely used vasodilator, increases cerebral blood flow (CBF) in older people with symptomatic small vessel disease, the main cause of VCI. METHODS: In a double-blind, placebo-controlled, cross-over trial, participants received tadalafil (20 mg) and placebo on two visits ≥7 days apart (randomized to order of treatment). The primary endpoint, change in subcortical CBF, was measured by arterial spin labelling. RESULTS: Tadalafil increased CBF non-significantly in all subcortical areas (N = 55, age: 66.8 (8.6) years) with greatest treatment effect within white matter hyperintensities (+9.8%, P = .0960). There were incidental treatment effects on systolic and diastolic blood pressure (-7.8, -4.9 mmHg; P < .001). No serious adverse events were observed. DISCUSSION: This trial did not identify a significant treatment effect of single-administration tadalafil on subcortical CBF. To detect treatment effects may require different dosing regimens.

Test-retest reliability of arterial spin labelling for cerebral blood flow in older adults with small vessel disease.

Cerebral small vessel disease (SVD) is common in older people and is associated with lacunar stroke, white matter hyperintensities (WMH) and vascular cognitive impairment. Cerebral blood flow (CBF) is reduced in SVD, particularly within white matter.Here we quantified test-retest reliability in CBF measurements using pseudo-continuous arterial spin labelling (pCASL) in older adults with clinical and radiological evidence of SVD (N=54, mean (SD): 66.9 (8.7) years, 15 females/39 males). We generated whole-brain CBF maps on two visits at least 7 days apart (mean (SD): 20 (19), range 7-117 days).Test-retest reliability for CBF was high in all tissue types, with intra-class correlation coefficient [95%CI]: 0.758 [0.616, 0.852] for whole brain, 0.842 [0.743, 0.905] for total grey matter, 0.771 [0.636, 0.861] for deep grey matter (caudate-putamen and thalamus), 0.872 [0.790, 0.923] for normal-appearing white matter (NAWM) and 0.780 [0.650, 0.866] for WMH (all p<0.001). ANCOVA models indicated significant decline in CBF in total grey matter, deep grey matter and NAWM with increasing age and diastolic blood pressure (all p<0.001). CBF was lower in males relative to females (p=0.013 for total grey matter, p=0.004 for NAWM).We conclude that pCASL has high test-retest reliability as a quantitative measure of CBF in older adults with SVD. These findings support the use of pCASL in routine clinical imaging and as a clinical trial endpoint.All data come from the PASTIS trial, prospectively registered at: https://eudract.ema.europa.eu (2015-001235-20, registered 13/05/2015), http://www.clinicaltrials.gov (NCT02450253, registered 21/05/2015).

Management of traumatic brain injury (TBI): a clinical neuroscience-led pathway for the NHS.

Following hyperacute management after traumatic brain injury (TBI), most patients receive treatment which is inadequate or inappropriate, and delayed. This results in suboptimal rehabilitation outcome and avoidable detrimental chronic effects on patients' recovery. This worsens long-term disability, and magnifies costs to the individual and society. We believe that accurate diagnosis (at the level of pathology, impairment and function) of the causes of disability is a prerequisite for appropriate care and for accessing effective rehabilitation. An expert-led, integrated care pathway is needed to deliver accurate and timely diagnosis and optimal treatment at all stages during a TBI patient's care.We propose the introduction of a specialist interdisciplinary traumatic brain injury team, led by a neurosciences-trained brain injury consultant. This team would engage acutely and for a longer term after TBI to provide accurate diagnoses, which guides subsequent management and rehabilitation. This approach would also encourage more efficient collaboration between research and the clinic. We propose that the current major trauma network is leveraged to introduce and evaluate this proposal. Improvements to patient outcomes through this approach would lead to reduced personal, societal and economic impact of TBI.

All change: a stroke inpatient service's experience of a new clinical neuropsychology delivery model.

Adults presenting to stroke services are frequently faced with the challenge of adjusting to a different life following a stroke. Difficulties often include cognitive impairments, such as memory deficits, attention and language difficulties, and mood disturbances such as anxiety and depression. It has been highlighted that psychological care for this group is just as important as physical rehabilitation. Psychological expertise may therefore be required for the multitude of problems that occur after a stroke. UK National guidelines recommend routine assessment and management of mood and cognition after stroke. The aim of this study was to evaluate a new stroke clinical neuropsychology service developed by the Department of Neuropsychology and Clinical Health Psychology, in order to meet the needs of stroke survivors and their families referred into a large acute hospital. This involved using a different skill mix of staff across one post delivering a service in an acute inpatient stroke unit. This model was evaluated and results revealed that the model delivered increased patient access to neuropsychological support, an expansion in provision of clinical work, along with positive multidisciplinary team feedback. This finding is key as where resources are limited, clinical services may benefit from adopting a 'skill mix' model to meet the varying needs of their patients in a timely manner. This model serves to raise the value of psychology to medical services.

Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS): study protocol for a randomised controlled trial.

BACKGROUND: Cerebral small vessel disease is a common cause of vascular cognitive impairment in older people, with no licensed treatment. Cerebral blood flow is reduced in small vessel disease. Tadalafil is a widely prescribed phosphodiesterase-5 inhibitor that increases blood flow in other vascular territories. The aim of this trial is to test the hypothesis that tadalafil increases cerebral blood flow in older people with small vessel disease. METHODS/DESIGN: Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS) is a phase II randomised double-blind crossover trial. In two visits, 7-30 days apart, participants undergo arterial spin labelling to measure cerebral blood flow and a battery of cognitive tests, pre- and post-dosing with oral tadalafil (20 mg) or placebo. SAMPLE SIZE: 54 participants are required to detect a 15% increase in cerebral blood flow in subcortical white matter (p < 0.05, 90% power). Primary outcomes are cerebral blood flow in subcortical white matter and deep grey nuclei. Secondary outcomes are cortical grey matter cerebral blood flow and performance on cognitive tests (reaction time, information processing speed, digit span forwards and backwards, semantic fluency). DISCUSSION: Recruitment started on 4th September 2015 and 36 participants have completed to date (19th April 2017). No serious adverse events have occurred. All participants have been recruited from one centre, St George's University Hospitals NHS Foundation Trust. TRIAL REGISTRATION: European Union Clinical Trials Register: EudraCT number 2015-001235-20 . Registered on 13 May 2015.

Cognitive impairment in dual diagnosis inpatients with schizophrenia and alcohol use disorder.

Cognitive impairment has been found independently among individuals with schizophrenia and individuals with alcohol use disorders. Less is known about the nature and severity of cognitive impairment in patients with a dual diagnosis, though the co-occurrence of these disorders may further exacerbate cognitive impairment. The study investigates the possible additive effect of alcohol use disorder and schizophrenia on cognitive impairment among patients diagnosed with schizophrenia. Participants were inpatients with schizophrenia (n=30), inpatients with a dual diagnosis of schizophrenia and alcohol use disorder (n=30), and matched controls (n=30): all completed a comprehensive neuropsychological battery. Both patient groups were significantly impaired, relative to controls, across the battery. Dual diagnosis patients were significantly more impaired than schizophrenia patients on delayed verbal memory, and executive functioning, primarily set-shifting, working memory, and planning, and had higher psychiatric morbidity scores. The findings provide support for an additive effect of the two disorders on cognitive impairment. These cognitive deficits may affect capacity to engage in treatment, increase risk of relapse, and adversely affect treatment outcomes. An understanding of the cognitive profile of people with dual diagnosis may help to tailor treatment delivery to meet their specific needs, enhance cognitive strengths, accommodate deficits and improve treatment outcomes.