Prehospital transdermal glyceryl trinitrate for ultra-acute ischaemic stroke: data from the RIGHT-2 randomised sham-controlled ambulance trial

BACKGROUND

The effect of transdermal glyceryl trinitrate (GTN, a nitrovasodilator) on clinical outcome when administered before hospital admission in suspected stroke patients is unclear. Here, we assess the safety and efficacy of GTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2).

METHODS

RIGHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4 hours of onset. The primary outcome was a shift in scores on the modified Rankin scale (mRS) at day 90. Secondary outcomes included death; a global analysis (Wei-Lachin test) containing Barthel Index, EuroQol-5D, mRS, telephone interview for cognitive status-modified and Zung depression scale; and neuroimaging-determined 'brain frailty' markers. Data were reported as n (%), mean (SD), median [IQR], adjusted common OR (acOR), mean difference or Mann-Whitney difference (MWD) with 95% CI.

RESULTS

597 of 1149 (52%) patients had a final diagnosis of ischaemic stroke; age 75 (12) years, premorbid mRS>2 107 (18%), Glasgow Coma Scale 14 (2) and time from onset to randomisation 67 [45, 108] min. Neuroimaging 'brain frailty' was common: median score 2 [2, 3] (range 0-3). At day 90, GTN did not influence the primary outcome (acOR for increased disability 1.15, 95% CI 0.85 to 1.54), death or global analysis (MWD 0.00, 95% CI -0.10 to 0.09). In subgroup analyses, there were non-significant interactions suggesting GTN may be associated with more death and dependency in participants randomised within 1 hour of symptom onset and in those with more severe stroke.

CONCLUSIONS

In patients who had an ischaemic stroke, ultra-acute administration of transdermal GTN in the ambulance did not improve clinical outcomes in a population with more clinical and radiological frailty than seen in previous in-hospital trials.

Effects of blood pressure and tranexamic acid in spontaneous intracerebral haemorrhage: a secondary analysis of a large randomised controlled trial

Background

Tranexamic acid reduced haematoma expansion and early death, but did not improve functional outcome in the tranexamic acid for hyperacute spontaneous intracerebral haemorrhage-2 (TICH-2) trial. In a predefined subgroup, there was a statistically significant interaction between prerandomisation baseline systolic blood pressure (SBP) and the effect of tranexamic acid on functional outcome (p=0.019).

Methods

TICH-2 was an international prospective double-blind placebo-controlled randomised trial evaluating intravenous tranexamic acid in patients with acute spontaneous intracerebral haemorrhage (ICH). Prerandomisation baseline SBP was split into predefined ≤170 and >170 mm Hg groups. The primary outcome at day 90 was the modified Rankin Scale (mRS), a measure of dependency, analysed using ordinal logistic regression. Haematoma expansion was defined as an increase in haematoma volume of >33% or >6 mL from baseline to 24 hours. Data are OR or common OR (cOR) with 95% CIs, with significance at p<0.05.

Results

Of 2325 participants in TICH-2, 1152 had baseline SBP≤170 mm Hg and were older, had larger lobar haematomas and were randomised later than 1173 with baseline SBP>170 mm Hg. Tranexamic acid was associated with a favourable shift in mRS at day 90 in those with baseline SBP≤170 mm Hg (cOR 0.73, 95% CI 0.59 to 0.91, p=0.005), but not in those with baseline SBP>170 mm Hg (cOR 1.05, 95% CI 0.85 to 1.30, p=0.63). In those with baseline SBP≤170 mm Hg, tranexamic acid reduced haematoma expansion (OR 0.62, 95% CI 0.47 to 0.82, p=0.001), but not in those with baseline SBP>170 mm Hg (OR 1.02, 95% CI 0.77 to 1.35, p=0.90).

Conclusions

Tranexamic acid was associated with improved clinical and radiological outcomes in ICH patients with baseline SBP≤170 mm Hg. Further research is needed to establish whether certain subgroups may benefit from tranexamic acid in acute ICH.

Trial registration number

ISRCTN93732214.

Remote platelet function testing using P-selectin expression in patients with recent cerebral ischaemia on clopidogrel

Background

Antiplatelet agents reduce recurrence after cerebral ischaemia but are not effective in all patients, in part because of treatment resistance. The primary aim was to assess the proportion of patients who are insensitive to clopidogrel. The secondary aim was to assess the association between insensitivity to clopidogrel and recurrent cerebrovascular events.

Methods

Following written informed consent, independent patients with a recent non-cardioembolic ischaemic stroke or transient ischaemic attack, and taking clopidogrel, were enrolled. Platelet function was assessed with remote measurement of surface expression of P-selectin (CD62P) using commercial kits sensitive to aspirin or clopidogrel. Participants’ general practitioners provided details on recurrent vascular events at least 90 days later. Data are mean (SD) and median [IQR]. Resistance was defined as: aspirin median fluorescence (MF) >500 units, clopidogrel MF >860 units. Non-parametric descriptors and tests were used.

Results

63 patients were recruited: mean age 64 (13.7) years, women 47%. At baseline, 59 (95%) patients were taking clopidogrel alone with 3 (5%) on combined clopidogrel and aspirin. Assessment of platelet surface P-selectin revealed: aspirin test 528 [317, 834], >500 54.8%; clopidogrel test 429 [303, 656], >860 11.3%. No participants on aspirin and clopidogrel showed aspirin resistance. Thirteen (20.6%) patients had a recurrent cerebrovascular event; those with an ischaemic stroke had a non-significantly higher baseline P-selectin using the clopidogrel test as compared with those with no recurrence: 626 [380, 801] versus 406 [265, 609], p=0.08.

Conclusions

Remote measurement of platelet function assessed using the platelet surface expression of P-selectin is feasible. 11% of patients taking clopidogrel showed resistance. No significant associations were noted between clopidogrel resistance and recurrent ischaemic events.

Improving the likelihood of neurology patients being examined using patient feedback

We aimed to establish whether recall of elements of the neurological examination can be improved by use of a simple patient assessment score.

In a previous study we demonstrated that in-patients referred to neurology at two United Kingdom (UK) hospitals were not fully examined prior to referral; we therefore designed a larger quality improvement report with 80% power to detect a 10% increase in tendon hammer or ophthalmoscope use following an educational intervention.

In-patients referred to neurology over a four month period (in hospitals in the UK (10), Jordan (1), Sweden (2), and the United Arab Emirates (1)) were asked whether they recalled being examined with a tendon hammer (T), ophthalmoscope (O), and stethoscope (S) since admission. The results were disseminated to local medical teams using various techniques (including Grand Round presentations, email, posters, discounted equipment). Data were then collected for a further four month period post-intervention.

Pre-intervention and post-intervention data were available for 11 centres with 407 & 391 patients in each arm respectively. Median age of patients was 51 (range 13-100) and 49 (range 16-95) years respectively, with 44.72% and 44.76% being male in each group. 264 patients (64.86%) recalled being examined with a tendon hammer in the pre-intervention arm, which significantly improved to 298 (76.21%) (p<0.001). Only 119 patients (29.24%) recollected examination with an ophthalmoscope pre-intervention, which significantly improved to 149 (38.11%)(p=0.009). The majority of patients (321 (78.87%)) pre-intervention recalled examination with a stethoscope, which significantly improved to 330 (84.4%) to a lesser extent (p=0.045).

Results indicate that most patients are not fully examined prior to neurology referral yet a simple assessment score and educational intervention can improve recall of elements of the neurological examination and thus the likelihood of patients being examined neurologically. This is the largest and - to our knowledge - only study to assess this issue. This has implications for national neurological educators.

SUSAC'S SYNDROME: A CASE SERIES FROM A REGIONAL NEUROSCIENCES UNIT

The clinical triad of branch retinal artery occlusions, hearing loss and encephalopathy constitutes Susac's Syndrome. This rare, immune mediated, microangiopathic disorder shows a variable course with a preponderance of 3 to 1 for women, mainly in their 2nd to 4th decade. The condition relies on diagnosis and early aggressive immunosuppressive therapy to avoid severe sequale. Unfortunately, due to the paucity of experience, and a variable disease course, often lacking all elements of the triad concurrently, diagnosis continues to be delayed.

We present five cases (Age 34–45, M:F–1:4) seen at our regional neurosciences centre, which highlight the diagnostic differences and challenges and the variety of management techniques adopted. Three patients had a monophasic illness and two had a relapsing remitting course. In addition, we provide an up-to-date literature review on the pathophysiology, diagnosis and management of this rare and fascinating condition.

Susac's disease, otherwise described as retinocochleocerebral vasculopathy, RED-M (retinopathy, encephalopathy, deafness associated microangiopathy) and SICRET (small infarcts of cochlear, retinal and encephalic tissues), is a syndromic pathology requiring the recognition of a triad of deficits to make a diagnosis. The relevance of this and the difficulty in diagnosis is exemplified in the cases presented here.

PILOCYTIC ASTROCYTOMA: A CASE OF NOT SO BENIGN INTRACRANIAL HYPERTENSION

Idiopathic intracranial hypertension (IIH) is a condition of raised CSF pressure without any apparent structural lesion or problem with venous drainage. We present a lady who was initially diagnosed with IIH, but was later found to have an unusual brain tumour.

A 30 year old lady presented in 2012 with a three month history of headaches, nausea and vomiting, two weeks of blurred vision and one week of double vision on looking left. Visual acuity was 6/6 on the right and 6/9 on the left with a left relative afferent pupillary defect, bilateral papilloedema and left lateral rectus palsy. MRI showed ventriculomegaly. Lumbar puncture revealed normal constituents with an opening pressure of 60 cm H2O. In the absence of a space occupying lesion or venous occlusion a diagnosis of IIH was made. A ventriculoperitoneal shunt was inserted and she was discharged but didn't attend follow-up. She re-presented in May 2014 with headaches and intermittent left arm and leg numbness. An MRI revealed widespread CSF pathway infiltration, leptomeningeal enhancement, tonsillar descent and an extensive cervical syrinx. She underwent posterior fossa decompression and biopsy, which was histologically confirmed as pilocytic astrocytoma.

Ventriculomegaly is not a feature of IIH. This case illustrates the wide differential of raised CSF pressure and that careful assessment of brain imaging and CSF constituents is required prior to making what is, in effect, a diagnosis of exclusion.

THE TOS2 STUDY: AN INTERNATIONAL MULTI-CENTRE AUDIT ASSESSING THE STANDARD OF NEUROLOGICAL EXAMINATION

Having previously demonstrated that in-patients referred to neurology at two UK hospitals were not fully examined prior to referral, we designed an audit with 80% power to detect a 10% increase in tendon hammer or ophthalmoscope use following an educational intervention.

In-patients referred to neurology over a 4 month period in the UK, Jordan, Sweden and the United Arab Emirates were asked whether they recalled examination with a Tendon hammer, Ophthalmoscope and Stethoscope since admission. Results were disseminated to local medical teams and data were collected for a further 4 months. Pre and post-intervention data were available for 11 centres with 407 and 391 patients in each arm. 264 patients (64.86%) recalled examination with a tendon hammer pre-intervention, which significantly improved to 298 (76.21%) (p<0.001). 119 (29.24%) recollected ophthalmoscopy pre-intervention, which significantly improved to 149 (38.11%) (p=0.009). 321 (78.87%) recalled examination with a stethoscope pre-intervention, which significantly improved to 330 (84.4%) (p=0.045). Most patients were not fully examined prior to neurology referral, yet a simple assessment score and educational intervention can improve the standard of neurological examination. This is the largest and – to our knowledge – only study to assess the standard of neurological examination internationally. This has implications for national neurological educators.