Project title:

The development of a method for acceptable and reliable extra-cranial detection of seizures in adults with intellectual disability and treatment-resistant epilepsy.

Type of research:

Experimental investigation to be followed by an application for clinical trial funding.


Epilepsy occurs often in adults with intellectual disability (ID). Across all those with an IQ below 70 it has an average prevalence of around 30% and for those with severe or profound ID the prevalence of epilepsy exceeds 50%. In addition, compared to the general population, epilepsy in people with ID is more often associated with treatment refractoriness and serious outcomes including injury or death [1, 2].

In order to best manage epilepsy it is important to be able to establish when seizures actually occur. Seizure detection is important for determining seizure frequency, for monitoring responses to changes in antiepileptic drug therapy and for the differential diagnosis of repeated paroxysmal behavioural changes, which present significant diagnostic and management difficulties in a proportion of adults with ID. However, many people with epilepsy and ID, particularly those with more severe ID, are unable to report when they have had a seizure and yet cannot be continuously observed by carers, especially at night, hence a lot of seizures go unnoticed [3], and current assistive technologies such as bed mats to identify a seizure, are limited in their applicability, sensitivity and specificity.

Improving diagnosis and management of seizures is likely to reduce the relatively high rate of sudden death in epilepsy (SUDEP) in this clinical group and to reduce the very high rates of potentially unnecessary emergency hospital admissions for epilepsy. (In a recent analysis Glover and Evison (2013) [4] found that seizures occurring in people with epilepsy were the most common cause of potentially preventable emergency hospital admissions in people with ID, leading to significant burdens for the effected individuals, their families and carers, and to significant costs for the NHS). Although EEG/video telemetry is the gold standard for seizure detection, this approach is expensive and limited to specialist in-patient units. It is difficult to tolerate for people with more severe ID and it is not practical for long term use or for application in people’s homes.

Research aims:

The aim of this research is to develop a process and an algorithm for the automatic detection of seizures in adults with an intellectual disability and severe epilepsy, based on the combined analysis of heart rate variability and accelerometry data. The development of such methodology, if it were feasible and acceptable for use in adults with ID, could support improved diagnosis of paroxysmal behavioural symptoms of unclear origin and better monitoring of the effects of antiepileptic medication in those with difficult-to-treat seizures.

Proposed methods:

This project will aim to recruit 25 adults with ID and intractable epilepsy, each with a seizure frequency of 20 or more per month. Recordings of ambulatory EEG, along with physiological data comprising heart rate variability, accelerometry and respiratory rate will be acquired from these individuals for two separate periods each of 72 hours duration. Altogether, from the study sample as a whole, this project will aim to record data from a minimum of 100 seizures, a number consistent with those analysed in previous studies. The number of recording sessions will be extended if required to reach a total of 100 seizures.


The research involves collaboration within Cambridge from the University of Cambridge Depart of Engineering, the MRC Cognition and Brain Sciences Unit and the Addenbrookes Hospital Depart of Clinical Engineering. The research will also involve collaboration with clinical staff in Hertfordshire and an academic at the University of East Anglia. The research will involve the development of collaboration with an industry partner; Rescon Ltd – a research, development and consulting company with a focus on solving complex biomedical systems problems relating to human performance.

Epilepsy Action – the largest UK epilepsy charity – which acts to represent the interests of people with epilepsy and their families and carers will be a collaborator, and Patient and Public (PPI) involvement will also be obtained from the NIHR Research Design Service for the East of England, University of Essex.

CLAHRC East of England will provide a uniquely suitable environment in which to undertake this research, providing as it does a combination of clinicians with expertise in Intellectual Disability and epilepsy, academics and industry with excellent skills in bio-technology development and analysis of large multi-modal datasets, and importantly, a large population of potential participants and beneficiaries of the research – as the region includes both significant population centres together with areas of relatively low accommodation costs where residential settings for adults with severe intellectual disabilities tend to congregate. The research will be based in Cambridge as this is where both the clinical monitoring and the data analysis resources are located. However, recruitment will be in Cambridgeshire, Hertfordshire and Norfolk and intellectual input, research training and development of the research outputs will take place across all these sites. In Norfolk, Cambridgeshire and Hertfordshire the work will involve the community ID teams and individuals with ID and epilepsy and in each of these counties.

For further information on this project, please contact Dr Howard Ring, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge

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