A Clinical Decision Aid for Diagnosing Transient Loss of Consciousness

NCT05367999 | Completed

• 1 other identifier: STH20060
• Study Type: observational
• Target: 186
• Locations: 1 country
• Sites: 2

Brief Summary

BACKGROUND: Transient loss of consciousness (TLOC) - defined as spontaneous disruption of consciousness not due to head trauma and with complete recovery - has a lifetime prevalence of 50%. It is one of the commonest neurological complaints in primary and emergency care. Over 90% of TLOC is due to either syncope, epilepsy or dissociative seizures (DS, also known as 'Psychogenic Nonepileptic Seizures'). The rapid and accurate distinction of these diagnoses is vital to allow appropriate further management but at least 20-30% of patients are not managed optimally or misdiagnosed. We have previously demonstrated that, in patients with established diagnoses of epilepsy, syncope, or DS, an automated classifier using only information from 36 questions based on patient experience and lay witness reports (the initial Paroxysmal Event Profile, iPEP) could accurately diagnose 86.0% of patients (with 100% sensitivity and 91.7% specificity for syncope) AIMS: To calibrate the iPEP for discrimination between syncope, epilepsy, and DS in patients newly presenting with TLOC, validate its performance in an independent sample, and to explore acceptability of the use of such a tool to people with TLOC and witnesses. METHODS: Nested qualitative-quantitative prospective single-centre development and validation of the iPEP in patients presenting to Emergency Departments, syncope or epilepsy clinics with first presentations of TLOC, with semi-structured interviews conducted with a purposive sample of participants from the quantitative study. The iPEP will be calibrated using a previously-described procedure for variable selection and training of Random Forest (RF) classifiers, and validated with assessment of overall classification accuracy, alongside sensitivity, specificity, positive and negative predictive values, and area under receiver-operating curve for each of the three target diagnoses. Performance will be evaluated against a benchmark set by results from previous research in patients with established diagnoses of epilepsy, syncope, and DS. OUTPUTS: Results will be submitted for publication in academic and professional literature. If performance from feasibility can be replicated in validation, the iPEP will be suitable to begin process of registration as a medical device for implementation in clinical pathways to minimise inappropriate referrals and treatment, streamline patient pathways, and enable earlier ordering of appropriate investigations to ensure prompt and appropriate diagnosis and management. If pilot performance could be replicated in this population and proportional savings from current estimated costs of misdiagnosis achieved, this could potentially save £63.9 million of annual UK healthcare expenditure.

Conditions

Consciousness Disorder

Keywords

TLOC; Seizures; Epilepsy; Syncope

Outcome Measures

Primary Outcomes (1)

• AUC for syncope

  We will compare classifier-predicted diagnoses against final diagnoses obtained by expert consensus review of medical records. We will define performance in terms of AUC for cardiogenic syncope.

  6 months post-presentation

Secondary Outcomes (1)

• Overall classifier accuracy

  6 months post-presentation

Other Outcomes (1)

• Participant experience

  6-month follow-up

Study Arms (1)

Patients presenting with TLOC

A concurrent nested qualitative-quantitative design is used. Patients first presenting to an ED with TLOC (and witnesses) who have contributed to the quantitative part of this project will be offered participation in a qualitative interview study after completion of the iPEP during the initial study procedure. Capturing variation based on diagnosis, gender, age and participant/witness role, a purposive sample of participating participants and witnesses will be invited to semi-structured interviews in which they will be prompted to discuss their experiences of using the iPEP and their views on the accuracy in describing their peri-episodal experiences.

Diagnostic Test: initial Paroxysmal Event Profile

Interventions

initial Paroxysmal Event Profile DIAGNOSTIC_TEST

The initial Paroxysmal Event Profile (iPEP) was derived from the paroxysmal event profile (PEP) and paroxysmal event observer (PEO) to provide a diagnostic tool aiming to differentiate between the most common underlying reasons for TLOC presentations: syncope, epilepsy, and dissociative seizures. The iPEP is a 35-item questionnaire developed from the PEP and PEO.5,25 The 5-point frequency scales used in response to each symptom in the PEP and PEO have been replaced with a binary 'present'/'not present' classification in recognition of the fact that the target patient group may have experienced only one or a few episodes of TLOC.

Patients presenting with TLOC

Eligibility Criteria

• Age: 16 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of screened admissions to the Emergency Department and Acute Medical Unit presenting with TLOC, as well as all new patients referred to the Neurology and Cardiology departments with TLOC.

You may qualify if:

• Patients first presenting with TLOC
• Referred to secondary care for diagnostic evaluation OR given firm diagnosis of syncope in accordance with European Society of Cardiology guidelines for syncope presentations not requiring further investigation
• Adult over the age of 16 years
• Able to complete iPEP questionnaire independently
• Participants do not need to be native English speaker but do need to have sufficient English language ability to complete iPEP without support

You may not qualify if:

• Unable to give informed consent to participation in research
• Unable to complete iPEP independently
• Previous specialist (neurological or cardiological) assessment of TLOC
• No firm clinical diagnosis of TLOC (and its cause) at end of 6-month follow-up period
• Evidence of previous specialist (neurological or cardiological) assessment of TLOC.

Sponsors & Collaborators

• Sheffield Teaching Hospitals NHS Foundation Trust: lead

Study Sites (2)

Royal Hallamshire Hospital

Sheffield, South Yorkshire, S10 2JF, United Kingdom

Location

Northern General Hospital

Sheffield, South Yorkshire, S5 7AT, United Kingdom

Location

MeSH Terms

Conditions

Consciousness Disorders; Seizures; Epilepsy; Syncope

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Neurocognitive Disorders; Mental Disorders; Brain Diseases; Central Nervous System Diseases; Unconsciousness

Study Officials

• Markus Reuber

  Honorary Consultant Neurologist

  PRINCIPAL INVESTIGATOR

• Alistair Wardrope

  Specialty Registrar in Neurology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 19, 2022
• First Posted: May 10, 2022
• Study Start: February 9, 2022
• Primary Completion: June 30, 2023
• Study Completion: June 30, 2023
• Last Updated: January 3, 2024

Record last verified: 2024-01

Data Sharing

• IPD Sharing: Will not share

Locations

GB (2)