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Recent bioterror attacks and other world events have foc used the medical community's attention on agents that might be used in biological warfa re. One ofthese potential biological weapons is Francisella tularen sis, a gramnegative coccobacillus that is one of the most inf ectious bacteria known. Ftularensis can cause seve re, even f atal, syste mic tularemia. Unde r normal circums tances, F tularensis is transmitted by infected ticks, insects, and other animals. As a weapo n ofterrorism, the bacterium would likely be disseminated as an ae rosol and contracted by inhala tion. Because many cases of tularemia are cha racterized by head and neck symptoms, otolaryngologists should befamilia r with the diagnosis and mana gement of this disease. In this article, we describe a case of zoonotic tularemia that manifested as a neck mass, and we review the pathophysiology, diagnosis, and treatm ent of tularemia. We also summarize what is known about its potential as a biol ogical weapon.

Presently devised single channel devices generate relatively primitive sensation of hearing. They provide some enhancement of communication skills for the totally deaf. Definite psychological advantages for the totally deaf have been observed. Pitch discrimination is by the mechanism of "periodicity pitch." No "place" pitch encoding is possible. The recognition of complex sounds is not possible. Multiple segments of auditory nerve must be stimulated in a manner which will stimulate the complex patterns of neural activity necessary for speech discrimination. Electrodes can be optimized and the pathophysiological consequences of electrical stimulation can be determined in experimental animals. The perceptual consequences of electrical stimulation, however, can best be determined in man himself. How much we will have to rely on known and future methods of aural rehabilitation will depend upon how well perceptual speech patterns can be generated by electrical stimulation of the auditory nerve.

Neurophysiological and anatomical studies in cats have been directed toward determining the feasibility of development of a multichannel acoustic nerve stimulation prosthesis with potential application as an aid for profoundly deaf individuals with surviving acoustic nerve. From recording experiments taking advantage of the binaural frequency response characteristics of neurons within the central nucleus of the inferior colliculus, the pattern of excitation across the acoustic nerve array can be defined for any intracochlear electrode array. These single-unit studies reveal that it is possible to excite a series of restricted sectors of the acoustic nerve array from within the scala tympani, with appropriately positioned electrodes mounted in silastic carriers that fill the scala (displace perilymph). Precisely constructed electrode arrays in carriers molded to fill the scala can be fabricated using dies of the scala made from soft-metal cochlear casts. Implantation of these multichannel electrode arrays does not lead to significant direct destruction of the acoustic nerve in prior normal or prior neomycin-deafened ears, over a time course of many months. [Supported by NIH Grant NS-11804.]

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