PubMed Health⌕ Search

Biomedical subjects

M Himelfarb

Publications and source records attributed to M Himelfarb.

6 recordsLinked to original sources
PubMed1993

[Diagnosis of Arnold-Chiari malformation by electronystagmography].

3 patients with Arnold-Chiari malformation with vertigo as the sole clinical presentation are described. 2 of them had been undiagnosed for many years despite repeated examinations, including CT scans. The third patient was diagnosed 2 weeks following the initial vertiginous attack. Downbeating nystagmus demonstrated by electronystagmography, indicating a pathological lesion at the craniocervical junction, was the key finding that led to the diagnoses. Following this finding, CT scan directed to the craniocervical junction showed the typical image of Arnold-Chiari malformation. The cases presented emphasize the important contribution of electronystagmography in the evaluation of vertigo due to intracranial lesions. However, computerized imaging examination remains the main diagnostic tool for intracranial pathologic processes.

Adult↗
PubMed1989

Are seismic communication signals transmitted by bone conduction in the blind mole rat?

The anatomy of the middle ear of the blind mole rat, a subterranean rodent that uses seismic signals for long distance communication, is described qualitatively and quantitatively. The ossicular chain is of the parallel type with a lever arms ratio of 0.55 and an effective areal ratio of stapedial footplate to eardrum of 0.09. Assuming an ideal mechanical transform, the calculated fraction of acoustical energy theoretically transmitted to the cochlea, indicate low efficiency for airborne sounds. This is in accordance with the relatively high electrophysiological and behavioral threshold, shown previously. We suggest that a unique morphology of the middle ear and of the articulation between the lower jaw and the skull, as well as a peculiar 'jaw listening behavior' enable seismic vibrations to be transmitted to the inner ear mainly by bone conduction, thereby compensating for the limitation in receiving airborne signals.

Animals↗
PubMed1985

Familial pemphigus vulgaris.

A case of familial pemphigus vulgaris is described in an uncle and his niece who developed the disease 18 years apart. The man died from pemphigus in 1964. The diagnosis was confirmed histopathologically in both cases, but immunofluorescent microscopic studies were performed only in the woman because the technique was not available in 1964. HLA typing in the woman and her daughter and sister showed A 26, BW 38 and DRW 4 in all of them. Clinical disease did not develop in the other family members.

Female↗
PubMedDate not supplied

Evidence for intracochlear impedance changes following ethacrynic acid administration.

The effects of intra-arterial 30-, 40-, and 50-mg/kg doses of ethacrynic acid upon cochlear function in guinea pigs were studied for periods of three to five hours. Cochlear potentials recorded in the first turn included the endocochlear potential, whole nerve response, cochlear microphonics, and summating potentials in scala media, scala tympani, and scala vestibuli. Evidence of organ of Corti damage at 50 mg/kg was found in addition to electrical impedance changes in the cochlear membranes at all dose levels.

Animals↗
PubMedDate not supplied

Study of neural excitation in the guinea pig cochlea using low-frequency acoustic modulation.

A low-frequency tone has been shown to modulate the amplitudes of cochlear microphonic (CM) and whole nerve (N1) response to a high-frequency tone pip. Whereas the N1 responses was always reduced and had two maxima per cycle of the low-frequency signal, the CM response changed from a single- to a double-maxima pattern as the modulator intensity was increased.

Acoustic Stimulation↗