Surgical treatment of vertigo by utriculostomy: an experimental study in sheep.

The objective of this study was to develop and test an endolabyrinthic microsurgical procedure for treatment of vertigo, the utriculostomy. This involves the application of local heat for obtaining a fistula in the membranous labyrinth, so as to establish communication between the endolymphatic and perilymphatic spaces at the utricle level. Before the procedure, an experimental model using quail eggs was built for pre-evaluation, and macroscopic and histological studies were performed in the temporal bones of three healthy sheep. Following this, the utriculostomy was performed through the oval window in 12 sheep. A microthermocautery was conceived by the first author and developed at Hospital de Clinicas de Porto Alegre. This equipment allows for control of temperature and duration of exposure to heat. Three months after the surgery, the animals were killed. A histological study of the temporal bones was performed to assess whether communication had been created between the endolymphatic and perilymphatic spaces, or whether a neomembrane had developed in the cauterized region. Histological sections of the vestibule of eight animals (three normal, five surgical) were analysed. All non-surgical cases presented a normal utricle wall. Three surgical cases (60%) presented a neomembrane. The absence of identifiable perforations in the utricle wall and the presence of neomembrane areas in 60% of the operated bones suggest that utriculostomy is a promising procedure for the treatment of Meniere's disease.

[Cavernous hemangioma of the internal auditory canal. Apropos of a case]. / Hémangiome caverneux intracanalaire. A propos d'un cas.

A case of cavernous hemangioma in the internal auditory canal was reported. There were no specific symptoms or physical or neurotological findings to differentiate from acoustic neuroma. The clinical and surgical aspects of this rare tumor were reviewed and discussed.

Effects of gender and head size on the auditory brainstem response.

Fifty audiologically normal young adults, 25 men and 25 women, were submitted to the auditory brainstem response (ABR) test. The mean latencies of the waves I, II, III, IV and V and the interpeak latencies (IPLs) I-III, I-V and III-V were calculated and compared to the normative values published by other groups. We have observed a great similarity among these values, specially in the interpeak latencies. The latencies of the principal ABR parameters were compared between the sexes showing significant differences in all the waves, particularly in the wave V. No significant correlations were found among the values when the head size and the ABR principal components latencies were confronted.

Sudden vertigo of central origin.

Intense vertiginous attacks with sudden onset and of several months' duration were observed in a group of patients following viral infection. Neurotological examination revealed different types of signs of involvement of the central vestibular apparatus. All of these patients became dizzier when medicated with vestibular depressor drugs, and could obtain symptomatic relief with corticosteroids. They became asymptomatic after a period of 3-4 months from the onset of the disease, but the signs of central vestibular involvement persisted for 6-12 months.

Controlled clinical trial of pentoxifylline versus cinnarizine in the treatment of labyrinthine disorders.

Seventy-six patients with labyrinthine diseases of vascular origin were treated in a 6-week double-blind comparative study with either 400 mg pentoxifylline ('Trental') or 75 mg cinnarizine 3-times daily. Clinical evaluations, supported by audiological tests and vectornystagmography, were carried out before and after treatment. Statistical analysis of the results showed pentoxifylline to be globally superior to cinnarizine and especially to have a more intense antivertiginous effect. No significant differences were observed between the two drugs in respect of tinnitus and hearing loss therapy. Side-effects were occasional, mild and well tolerated in the pentoxifylline group, and more pronounced and frequent with cinnarizine.

The Mondini dysplasia - a clinical study.

The authors describe a clinical approach to the diagnosis and treatment of sensory-neural hearing loss associated to the Mondini dysplasia. The first element of diagnostic suspicion was represented either by a history of fluctuant and progressive hearing loss or by electrocochleography patterns showing multiple-peaked acoustic nerve action potentials similar to those observed in Ménière's disease. Confirmation of the diagnosis was obtained by temporal bone polytomography. An endolymphatic subarachnoid shunt was performed in 22 ears of 18 patients. The results, although preliminary, suggest that the shunt effectively contributes to stabilize the hearing and arrest the further progression of the hearing loss.

Vestibular decruitment. A study of the phenomenon in a normal population.

Vestibular decruitment is a phenomenon characterized by the presence of less intense responses following stronger vestibular stimulation, and its presence has been considered as indicative of central vestibular pathology. In this study conducted in 24 normal individuals, with normal caloric responses, decruitment was observed in 58.3% of the cases. These decruitments were of types I and II as defined by Torok. Type III decruitment was not seen in these patients. In view of the present findings the actual meaning of the phenomenon must be investigated in larger numbers of patients with peripheral or central vestibular disorders.

Flunarizine and cinnarizine as vestibular depressants. A statistical study.

The authors analysed the vestibular depressant activity of flunarizine and cinnarizine, as compared to a placebo, in 58 patients with peripheral labyrinthine disorders. The activity of the medications was judged by the reduction of the average velocity of the slow phase of the post-caloric nystagmus, before and after treatment. In spite of being administered in a smaller dosis, flunarizine appeared to have a more intense vestibular supressant activity, as judged by different statistical tests.