W. J. Adie and his "pyknolepsy," a century ago

On November 8, 1923, William John Adie described an unusual disorder to the Section of Neurology of the Royal Society of Medicine. The condition comprised frequent momentary stereotyped impairments of consciousness that occurred in children, did not respond to antiseizure medications, and did not develop into epilepsy, as that term was then commonly understood, since no convulsive seizures occurred. After some time, the episodes terminated spontaneously, leaving the sufferer unhandicapped and neurologically intact. Almost certainly, Adie had described the present-day entity of childhood absence epilepsy. He termed it "pyknolepsy," knowing that the name "pyknolepsie" had been used for a similar disorder in Germany from 1916 onwards, though not reported elsewhere. Following Adie's account, published in 1924, reports of the disorder appeared in the English and French-language literature and continued to be published in German. It became increasingly accepted that pyknolepsy was a form of epilepsy that was part of Lennox's petit mal triad. The word pyknolepsy itself never became widely used and is now largely forgotten. Adie never took up the topic in print again. However, he had awakened English-language readers to one component in a broadening of the concept of what constituted epilepsy.