Electroencephalography: maturing gracefully

Eighty-five years ago Hans Berger, working in Jena, Germany, used silver wires inserted under the scalp of human subjects to record a mysterious 10 Hz wobble. Later, he acquired a valve amplifier to drive his galvanometer and reported his discoveries between 1929 and 1935, including the changes in cerebral activity after eye closure, in Archiv für Psychiatrie und Nervenkrankheiten as “Über das Electrenkephalogramm des Menschen”. To suggest that the brain’s electrical activity was detectable outside the skull sorely tested the credulity of his contemporaries. However, by the time unilateral spikes were correlated with clonic jerking of the contralateral extremities and 3 Hz spike and wave with absence attacks, the importance and potential of Berger’s original rhythms were realised.

Would Hans be disappointed with the modern applications of his discovery? I think not. Admittedly, developments in EEG technology have been slow in comparison to the gargantuan, athletic strides made in structural imaging of the brain—but the EEG remains integral to clinical neurological practice,1 albeit with an intangible, even enigmatic, appeal to those of us who like to see our patients’ brain waves. Despite the limitations imposed by standard electrode placement, which preclude recording from basal or mesial cerebral regions, this “poor man’s functional imaging”, has matured to join a more sedate masters’ class. The EEG has the unique advantage in neurodiagnostics of not only spatial but also temporal resolution. On the other hand, Berger’s legacy has not fulfilled the hopes of subsequent generations of psychiatrists searching for an application in neurobehavioural disorders.2

Digital technology has replaced the paper, pen and ink machines which once spewed an impressively weighty ream of paper, later to lay dormant in vast musty corridors of hospital basements. Contemporary systems effortlessly record and store hours of EEG, with simultaneous …