Mastoid subperiosteal abscess.

Subperiosteal abscess was the indication for surgery in every child with acute mastoiditis who underwent mastoidectomy at our institution since 1972. Nineteen such patients are discussed herein. Positive bacteriologic findings included Streptococcus pyogenes in three patients, Streptococcus pneumoniae in three patients, Mycobacterium tuberculosis in two patients, and enterococcus in the one patient with cholesteatoma.

Acute mastoiditis in children: a review of 54 cases.

Fifty-four children with acute mastoiditis were managed at the Los Angeles County-University of Southern California Medical Center from 1972 through 1982. Our criteria for the diagnosis of acute mastoiditis are acute or subacute otitis media, postauricular swelling and erythema, protrusion of the auricle, and clouding of mastoid air cells on radiographs. Thirty-one (57%) recovered with conservative therapy consisting of early myringotomy and intravenous antibiotic, usually ampicillin.

Electrical stimulation of the brain. II. Effects on the blood-brain barrier.

Acute and chronic studies of the effects of electrical stimulation on the blood-brain barrier (BBB) of the cat cerebral cortex are reported. The findings emphasize the importance of avoiding direct-coupled, monophasic waveforms in stimulating nervous tissue. Biphasic waveforms with balanced charges in each half-wave of the stimulating pulse can be used for up to 36 hours of continuous stimulation if the charge per phase (Q/ph) does not exceed 0.