Abstracts

Rationale: Epilepsy is the most common serious neurological disease after stroke. At least 1 in 26 people will at some point in their life suffer a seizure and ~1% of the world population suffer chronic epilepsy, with recurring seizures. Seizures are caused by intermittent brain electrical disturbances, which whilst brief and often infrequent cause significant disability, injury, and death.

The accurate diagnosis of epilepsy in a patient who has suffered a seizure, or those who have “black-outs” where the diagnosis remains uncertain, is complicated because conventional diagnosis relies on ‘long term' (5-7 days) in-patient video EEG (VEEG) monitoring, performed in a specialized epilepsy monitoring unit (EMU) or ambulatory EEG (AEEG) monitoring at home.

Unfortunately, VEEG and AEEG involve invasive scalp-based electrodes installed by training persons, a low yield of capture events given the infrequency of seizure events and often poor signal to noise due to moving cables and poor electrode interfacing.

Alternatively, patients monitor and self-report their seizure activity in an out-patient setting, this is unreliable with both over and under-reporting of events, complicating management and appropriate therapy.

The current shortcomings in the accurate diagnosis of epilepsy contribute to patients being misdiagnosed. Without an accurate means of objectively assessing these patients using long-term monitoring, many patients suffer from an impaired quality of life due to inadequate clinical management or overtreatment.

We are developing a new sub scalp device called Minder®, capable of significantly extending the data capture period and providing clinicians with more information to aid diagnosis and management.

Methods: Minder consists of a sub-scalp lead containing 4 recording electrodes. The electrodes sense and transmit neural events to the implanted processing unit. This implanted processor, also implanted sub-scalp process the brain signals and transmits them through the coil to the externally worn coil and wearable processor. The signal is then transmitted via Bluetooth link to a smart phone. The smart phone allows the signals to be transferred to the cloud where clinicians can have access allowing them to review the data.

Patients were enrolled into a study to evaluate the ultra-long-term EEG recordings from the minder and to compare these signals to the standard 10-20 scalp-based systems. During the evaluation patient underwent a minimum of two VEEG or AEEG monitoring sessions that lasted 7 days each. The Minder system was also recording at these times.

Results: We compared the recording from the Minder system to those captured at the same time with a 10-20 scalp system in an out-patient setting. Minder recordings were able to identify similarly clinically important EEG signals when compared to the 10-20 recordings. These included interictal epileptiform discharges, seizure activity, and sleep architecture.

Conclusions: We have described an ultra-long-term EEG recording system that will enable clinicians to collect EEG data from patients for weeks, months, and years, potentially improving the diagnosis and management of epileptic disorders.

Funding: Please list any funding that was received in support of this abstract.: Study was supported by Epiminder.