Lethargic Encephalitis

For the past nine years we have had at the research laboratory of the health department of New York City a meningitis division, the function of the members of which is to see in consultation all kinds of meningeal conditions for differential diagnosis and treatment.In this connection we have seen over 1,000 cases of meningitis of various kinds, 600 or more cases of poliomyelitis and over 700 cases of men- ingism with various diseases, besides small numbers of cases of unmer- ous other conditions, so that we have had a fairly good background for the study of a new type of meningeal or cerebral disease.Last October, as a member of the research laboratory of the health department of New York City, I began to see a new type of disease.The majority of these patients gave a history of influenza followed in a varying length of time by headache, drowsiness and apathy, usually accompanied by a low irregular fever, strongly suggesting a slowly developing tuberculous meningitis.One of the earliest patients, "X," showed extreme restlessness instead of drowsiness, marked muscular weakness and some paralysis of the cranial nerves.These conditions suggested a variety of diagnoses.Meningism seemed possible in cer¬ tain instances, perhaps caused by some gastro-intestinal disorder, or it may have followed, instead of accompanied, influenza ; this, however, was ruled out as the spinal fluid showed a marked increase in the protein elements and cejls instead of being normal, as is the rule in meningism.Syphilitic disease was suspected, especially in "X," but this was disproved by the negative Wassermann test and by the char¬ acter of the gold chlorid curve.Brain tumor must be differentiated in certain of the more severe cases, and this differentiation has proved a stumbling block to some very eminent neurologists.Tuberculous meningitis was considered in many cases, but this diagnosis was dis¬ carded because of failure to find the tubercle bacillus either by smear or by animal inoculation, the normal reduction of Fehling's solution and the favorable termination.In some instances the encephalitic type of poliomyelitis was suggested by the clinical picture and by the spinal fluid findings, but this type is rare even in epidemics of poliomyelitis.