Changes in blood neurotransmitter and steroid levels during evoked vertigo.

HYPOTHESIS AND BACKGROUND: Experimental evidence suggests that steroids as well as various neurotransmitters are critically involved in the functioning of the vestibular system in health and disease. Yet there are no pertinent human data. We hypothesized that changes in the serum levels of cortisol and plasma levels of excitatory and inhibitory neurotransmitters may occur during evoked vertigo. SUBJECTS AND METHODS: Ten healthy volunteers (median age 37, range 21-57) entered the study. Subjects were investigated at rest and at the time of maximal nystagmic reaction during caloric irrigation. The determination of glutamate, aspartate, and gamma-aminobutyric acid (GABA) was performed by reverse phase high-performance liquid chromatography, whereas cortisol measurements were performed with an immunoenzymatic assay with fluorescence polarization. RESULTS: During evoked vertigo, cortisol levels increased from a baseline value of 11.86 (+/-1.272) microg/dl to 14.375 (+/-2.183) microg/dl (p < 0.01), whereas all neurotransmitter levels decreased significantly. Glutamate levels, for instance, fell from a resting value of 25.99 (+/-6.30) ng/ml to 17.40 (+/-5.50) ng/ml (p < 0.001), and aspartate and GABA decreased as well. CONCLUSION: Evoked vertigo is consistently associated with an increase in steroid serum levels and accompanying decreases in the plasma levels of glutamate, aspartate, and GABA. The possible underlying mechanisms and the functional significance of these findings are discussed.

Management of tracheal stenosis with a titanium ring and nasal septal cartilage.

Surgical management of subglottic laryngeal and upper tracheal stenosis remains a formidable challenge. The significant number of proposed techniques only highlights the difficulties associated with effectively managing this problem. Between 1996 and 1999, seven patients with stenosis of the upper trachea were treated. The stenosis resulted from long-term intubation during intensive-care hospitalization in five patients and from tracheotomy complications in the other two. Six patients were male and one female, their ages ranging between 13 and 60 years. The mean postoperative observation period was 3 years (1.5-4.5 years). In all patients, the stenosis exclusively involved the upper tracheal segment, measuring from 2 to 5 cm in length. The stenotic area of the trachea is exposed, and the local application of a solution of mitomicin C for a duration of 4 min is performed. A graft consisting of cartilage and mucosa is harvested from the nasal septum and is fixed with sutures to a titanium semi-ring. After the fixation of the graft on the ring, the entire construct is placed on the stenosed segment of the exposed trachea. The graft must cover the anterior exposed face of the trachea with the lateral members of the semicircular titanium ring adjacent to the lateral walls of the trachea, externally. The lateral tracheal walls are attracted laterally with sutures and are attached on the edges of the semicircular titanium ring. Four of the patients in whom no tracheotomy had been performed preoperatively needed none at all intraoperatively, and they were decannulated normally at the end of the procedure. Tracheotomy was deemed necessary for one patient's safety and was maintained for 7 days. In one patient with a preoperative tracheotomy, the point of the tracheotomy was displaced lower on the trachea and was maintained there for 7 days. The course of management described here and employed on seven patients involves a safe surgical procedure with excellent results. The placement of the titanium ring offers very good support for the graft and maintains the patency of the tracheal lumen. The main reasons for the failure of techniques using only cartilage grafts are therefore avoided. The number of cases presented here is certainly too small to establish definite conclusions; however, the initial results are extremely satisfying and urge us to suggest the use of this method in indicated cases.

Ossiculoplasty with the use of autografts and synthetic prosthetic materials: a comparison of results in 165 cases.

One hundred and sixty-five cases of different kind of ossiculoplasty in patients suffering from chronic middle ear disease were performed at the ENT department of Papanikolaou Hospital in Thessaloniki, Greece, during the years 1988-1990. There were 40 cases of incus transposition, 47 cases in which polyethylene TORPs and PORPs were used and 77 cases of hydroxylapatite prostheses (41 TORPs and 37 double notch PORPs). Hearing success was defined as a post-operative air-bone gap of < 20 dB. According to this criterion 74 per cent of the incus transposition cases were successful, 61 per cent of the polyethylene TORPs, 65 per cent of the hydroxylapatite TORPs, 40 per cent of the polyethylene TORPs, and 89 per cent of the double notch hydroxylapatite PORPs. It is obvious that ceramic PORPs produced the best results, while there was no statistical difference, regarding the hearing improvement, among the different kinds of TORPs which were used. Extrusion rate and other kinds of complications are also discussed, as well as a case of severely damaged ceramic TORP, within two years due to middle ear infection.

Branchio-oto-renal dysplasia associated with tetralogy of Fallot.

Branchio-oto-renal dysplasia in its full expression consists of external ear malformations, cervical fistulas or cysts, preauricular pits, hearing loss of conductive sensorineural or mixed type, and renal anomalies. The syndrome is inherited in an autosomal dominant mode. We present a sporadic case of BOR dysplasia associated with tetralogy of Fallot in a 30-month-old girl. The clinical aspects of the disease are discussed briefly.