Our present literature is teeming with symptomatology and case reports of lethargic encephalitis. Since v. Economo, 1 in the spring of 1917, reported his first thirteen cases in detail, similar clinical conditions have been observed on the Eastern Continent as well as in this country. It first manifested itself on our Eastern coast in the fall of 1918 (Abrahamson 2 ), gradually spreading westward. In the spring and summer of 1919, cases were reported throughout the Middle West (Bassoe, 3 Riggs, 4 Hammes 5 ), and in October, 1919, it appeared almost simultaneously in Portland (House 6 ), in Seattle and in Tacoma (Winslow 7 ). We have had an opportunity to observe twenty-seven cases, six of which occurred since the recent influenza epidemic and in which the clinical picture differed somewhat from those observed earlier. The onset was usually gradual. Severe diffuse headaches, disappearing rapidly after the first four to ten days, occurred eleven times in our series. Asthenia, lethargy,