GETTING YOUR BRAIN WIRED FOR AN AMBULATORY EEG

                                                                                   

AMBULATORY  EEG

Introduction

Ambulatory electroencephalography (AEEG) monitoring is a relatively recent technology that allows prolonged electroencephalographic (EEG) recording in the home setting.^[1] Its ability to record continuously for up to 72 hours increases the chance of recording an ictal event or interictal epileptiform discharges. AEEG is a less expensive alternative to inpatient monitoring, with costs that are 51-65% lower than a 24-hour inpatient admission for video/EEG monitoring.^[2]

Continuous cardiac monitoring was first described by Holter in 1961.^[3] The development of portable EEG recording proved more problematic than the Holter monitor because of the need for signal amplification and multichannel recording. A multichannel portable recorder was developed in the early 1970s. This technology was later adapted to EEG recording, and miniature preamplifiers that could be worn on the head were developed.^{[4, 5]}

Early clinical investigations documented the ability of AEEG to record identifiable focal and generalized epileptiform activity.^{[6, 7]} In 1982, Ives introduced a 16-channel AEEG that utilized signal multiplexing.^[8] The 16 channels allowed improved spatial resolution and localization but recorded discrete samples rather than continuous EEG.

In 1983, a cassette tape AEEG system was introduced; it used off-head preamplifiers that had continuous 8-channel recording capability, real-time identification, and gain and filter adjustments.^{[9, 10, 11, 12]}

In the past decade, computer technology has enabled portable recording of up to 36 channels with sampling rates of up to 400 Hz. Currently, numerous AEEG systems are available commercially (see the image below).

Components of an ambulatory EEG system.
                                   What is causing my all-too-frequent apparent absence seizures? Today Thomas took me once again to the Western General for yet another in a series of madcap adventures, To my surprise, a couple of dozen wires were glued to my skull for a 24 EEG. This is my fourth diagnostic test since the gobsmacking advice which I received at the same illustrious institution in March
                                       PREVIOUS STRANGE ADVICE FROM A CONSULTANT NEUROLOGIST
                                                       Afterwards, Thomas took me for a slap up meal in Silverknowes                                                                                

                                      WIth apologies to Donald Trump, and with no intentipn to give offence to the waiter or anybody else