Titin founder mutation is a common cause of myofibrillar myopathy with early respiratory failure

OBJECTIVE

Titin gene (TTN) mutations have been described in eight families with hereditary myopathy with early respiratory failure (HMERF). Some of the original patients had features resembling myofibrillar myopathy (MFM), arguing that TTN mutations could be a much more common cause of inherited muscle disease, especially in presence of early respiratory involvement.

METHODS

We studied 127 undiagnosed patients with clinical presentation compatible with MFM. Sanger sequencing for the two previously described TTN mutations in HMERF (p.C30071R in the 119th fibronectin-3 (FN3) domain, and p.R32450W in the kinase domain) was performed in all patients. Patients with mutations had detailed review of their clinical records, muscle MRI findings and muscle pathology.

RESULTS

We identified five new families with the p.C30071R mutation who were clinically similar to previously reported cases, and muscle pathology demonstrated diagnostic features of MFM. Two further families had novel variants in the 119th FN3 domain (p.P30091L and p.N30145K). No patients were identified with mutations at position p.32450.

CONCLUSIONS

Mutations in TTN are a cause of MFM, and titinopathy is more common than previously thought. The finding of the p.C30071R mutation in 3.9% of our study population is likely due to a British founder effect. The occurrence of novel FN3 domain variants, although still of uncertain pathogenicity, suggests that other mutations in this domain may cause MFM, and that the disease is likely to be globally distributed. We suggest that HMERF due to mutations in the TTN gene be nosologically classified as MFM-titinopathy.

Auditory neuropathy spectrum disorder: its prevalence and audiological characteristics in an Indian tertiary care hospital

OBJECTIVE

Auditory neuropathy spectrum disorder (ANSD) has become a well accepted clinical entity. ANSD has now become easy to recognize with advent of test battery approach for hearing loss evaluation. However, little is known about its epidemiology and aetiology, especially its prevalence and incidence in India. This study was conducted to determine the prevalence and audiological characteristics of ANSD in our tertiary care hospital at New Delhi, India.

METHODS

We prospectively enrolled all the paediatric cases i.e. less than 12years of age referred to our outpatient department for hearing evaluation. All the cases were evaluated using complete audiological test battery consisting of pure tone audiometry (PTA), impedance audiometry, acoustic reflexes, otoacoustic emissions (OAE), and brain stem evoked response audiometry (BERA). The instrument used was GSI Audera. BERA with both condensation and rarefaction polarity was performed in cases with absent wave V even at highest intensity levels. The criteria used for diagnosis of ANSD was normal or near normal cochlear hair cells (sensory) function (preservation of otoacoustic emissions and/or cochlear microphonics) and absent or abnormal auditory nerve function (absent or severely abnormal auditory brainstem potentials). A repeat test battery was performed after 3months on the diagnosed cases of auditory neuropathy. Based on their behavioural findings the appropriate management programme was formulated.

RESULTS

A total of 487 paediatric cases were referred for hearing evaluation. 183 (37.6%) cases showed absent BERA and 26(5.3%) cases fulfilled the diagnostic criteria for ANSD. Repeat examination after 3months revealed presence of OAE's in 57.6% (15/26) cases while cochlear microphonics were present in all the 26 cases.

CONCLUSION

The prevalence of ANSD in our study is 5.3% and in children diagnosed with severe to profound hearing loss is 14%. Presence of cochlear microphonics with absent BERA seems to be reliable criteria for diagnosing ANSD.

Altered interictal saccadic reaction time in migraine: a cross-sectional study

AIMS

The underlying mechanisms of migraine remain poorly understood, partly because we lack objective methods for quantitative analysis of neurological function. To address this issue, we measured interictal saccadic latency in migraineurs and controls.

METHODS

In a cross-sectional study, we compared interictal saccadic latency distributions of 12,800 saccades in 32 migraineurs with 32 age- and sex-matched controls.

RESULTS

The variability of migraineurs' reaction time distributions was significantly smaller (σ = 1.01 vs. 1.13; p < 0.05) compared with controls. In addition, a smaller proportion of migraineurs generated 'early' saccades (31% vs. 56%: p < 0.05). Sensitivity/specificity analysis demonstrated the potential benefit of this technique to diagnostic discrimination.

CONCLUSIONS

The migraineur's brain behaves significantly differently from that of a control during the interictal period. By analysing whole distributions, rather than just means, data can be related directly to current neurophysiological models: specifically, the observed decrease in variability suggests a functional deficit in the noradrenergic systems influencing the cerebral cortex. From a clinical perspective, this novel method of characterising neurological function in migraine is more rapid, practicable, inexpensive, objective and quantitative than previous methods such as evoked potentials and transcranial magnetic stimulation, and has the potential both to improve current diagnostic discrimination and to help guide future research into the underlying neural mechanisms.

Combined laryngocele secondary to localized laryngeal amyloidosis

Laryngocele is a benign condition due to abnormal dilatation of the laryngeal saccule. Localized amyloidosis causing laryngocele is a rare entity with few reports in the literature. We present a young male patient with a large combined laryngocele secondary to laryngeal amyloidosis.

Peri-operative Replacement of Exogenous Steroids (PREdS): a national audit of current peri-operative prescribing for patients taking therapeutic steroids

INTRODUCTION

Approximately 1% of the UK population take oral corticosteroids for ≥ 28 days each year, for broadly two reasons: deficiency in corticosteroid requiring replacement; or therapeutic corticosteroid for inflammatory conditions. Acute deficiency can occur at times of physiological stress (e.g. surgery), potentially leading to major complications. The Association of Anaesthetists' 2020 consensus guideline provides detailed advice for the management of glucocorticoids during the peri-operative period for patients with adrenal insufficiency. This national audit aimed to assess compliance with this guideline.

METHODS

Data were collected from 59 Trusts over 14 consecutive days for all eligible patients undergoing procedures under the care of an anaesthetist. Patients who were prescribed ≥ 5 mg oral prednisolone equivalents pre-operatively, in whom supplementary corticosteroid would be indicated, were compared with those prescribed < 5 mg oral prednisolone equivalents.

RESULTS

Operations for 21,731 patients were audited: 277 (1.3%) patients were taking therapeutic corticosteroids. Detailed peri-operative data were collected for all patients receiving therapeutic corticosteroids: 201/277 (73%) were ASA physical status ≥ 3; 184/277 (66%) underwent elective procedures; and 252/277 (91%) were prescribed prednisolone pre-operatively, of whom 219/277 (79%) were prescribed ≥ 5 mg oral prednisolone equivalents. In the patients who were prescribed ≥ 5 mg oral prednisolone equivalents, 186/219 (85%) received pre-operative glucocorticoid supplementation and 97/219 (42%) received it postoperatively; however, only 67/219 (31%) and 43/219 (20%) respectively received glucocorticoid supplementation according to the guidelines. Overall, peri-operative prescribing was compliant in 19/219 (9%) patients. A similar proportion, 30/219 (14%), received no supplementation. In the patients taking < 5 mg oral prednisolone equivalents pre-operatively, 28/58 (48%) received inappropriate supplementation.

CONCLUSIONS

Despite 125/277 (45%) of anaesthetists reporting Association of Anaesthetists' guidelines use, compliance remained low, with adherence in only 27/125 (22%) patients. Further research is required to identify the correct peri-operative strategy for patients taking therapeutic corticosteroids.

Does intermittent nutrition enterally normalise hormonal and metabolic responses to feeding in critically ill adults? A protocol for the DINE-Normal proof-of-concept randomised parallel-group study

INTRODUCTION

Over half of patients who spend >48 hours in the intensive care unit (ICU) are fed via a nasogastric (NG) tube. Current guidance recommends continuous delivery of feed throughout the day and night. Emerging evidence from healthy human studies shows that NG feeding in an intermittent pattern (rather than continuous) promotes phasic hormonal, digestive and metabolic responses that are important for effective nutrition. It is not yet known whether this will translate to the critically ill population. Here, we present the protocol for a proof-of-concept study comparing diurnal intermittent vs continuous feeding on hormonal and metabolic outcomes for patients in the ICU.

METHODS AND ANALYSIS

The study is a single-centre, prospective, randomised, open-label trial comparing intermittent enteral nutrition with the current standard practice of continuous enteral feeding. It aims to recruit participants (n=30) needing enteral nutrition via an NG tube for >24 hours who will be randomised to a diurnal intermittent or a continuous feeding regimen with equivalent nutritional value. The primary outcome is peak plasma insulin/c-peptide within 3 hours of delivering the morning intermittent feed on the second study day, compared with that seen in the continuous feed delivery group at the same time point. Secondary outcomes include feasibility, tolerability, efficacy and metabolic/hormonal profiles.

ETHICS AND DISSEMINATION

We obtained ethical approval from the Wales Research Ethics Committee 3 prior to data collection (reference 23/WA/0297). We will publish the results of this study in an open-access peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT06115044.

The fragility index in randomised controlled trials of interventions for aneurysmal subarachnoid haemorrhage: A systematic review

Background

Fragility analysis supplements the p-value and risk of bias assessment in the interpretation of results of randomised controlled trials. In this systematic review we determine the fragility index (FI) and fragility quotient (FQ) of randomised trials in aneurysmal subarachnoid haemorrhage.

Methods

This is a systematic review registered with PROSPERO (ID: CRD42020173604). Randomised controlled trials in adults with aneurysmal subarachnoid haemorrhage were analysed if they reported a statistically significant primary outcome of mortality, function (e.g. modified Rankin Scale), vasospasm or delayed neurological deterioration.

Results

We identified 4825 records with 18 randomised trials selected for analysis. The median fragility index was 2.5 (inter-quartile range 0.25-5) and the median fragility quotient was 0.015 (IQR 0.02-0.039). Five of 20 trial outcomes (25%) had a fragility index of 0. In seven trials (39.0%), the number of participants lost to follow-up was greater than or equal to the fragility index. Only 16.7% of trials are at low risk of bias.

Conclusion

Randomised controlled trial evidence supporting management of aneurysmal subarachnoid haemorrhage is weaker than indicated by conventional analysis using p-values alone. Increased use of fragility analysis by clinicians and researchers could improve the translation of evidence to practice.