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Biomedical subjects

P Froehlich

Publications and source records attributed to P Froehlich.

29 records · Page 2Linked to original sources

A clinical study of human type IV collagen as tympanic membrane grafting material. Preliminary noncomparative study.

OBJECTIVE: To evaluate tolerance for this middle-ear implant and its effectiveness in eardrum healing under various pathologic conditions. SETTING: A 12- to 18-month follow-up case series at an institutional referral center offering hospitalized care. PATIENTS: Twenty-six eligible volunteers suffering from tympanic perforation or tympanic pocket retraction class II and III in Tos' classification. INTERVENTION: Patients underwent implantation with the type IV collagen film (film called "MTY" from the French membrane tympanique). The surgical procedure was similar to those using the temporal aponeurosis or the tragal perichondrium. OUTCOME MEASURE: Anatomic criteria was determined by otoscopy, and functional audiometric criteria was determined by air-borne gap measurements and by effects on cochlear function. RESULTS: Twenty-two of 26 patients were completely healed after 6 months, with no subsequent evolution. Nineteen of 26 subjects underwent a 1-year postoperative audiometric follow-up examination: 13 (68%) had an air-borne gap less than 10 dB, four (21%) had between 11 and 20 dB, and two (11%) had between 21 and 30 dB. Adverse effects included one patient whose MTY fell into the middle ear, three patients with transient myringitis, and one patient with otitis media with effusion. CONCLUSIONS: A human type IV collagen film may be a possible alternative to autologous tissue in tympanic membrane reconstruction. This new biomaterial was tested on patients with various diseases common in clinical otology, and demonstrated a good biocompatibility of MTY in the different pathologic conditions of chronic otitis media. A future randomized, controlled trial will randomly allocate patients to receive either MTY collagen film or tissue from the temporal aponeurosis.

Adolescent↗

Lack of association between transiently evoked otoacoustic emission amplitude and experimentation linked-factors (repeated acoustic stimulation, cerebrospinal fluid pressure, supine and sitting positions, alertness level).

Changes in transiently evoked otoacoustic emissions (TEOAEs) occur during sleep and during tasks requiring attention. This can be due to a central nervous system effect on the cochlea. But, an additional or dominant influence by non-controlled factors is possible. In this paper, the effect of click-stimulus repetition, lying and sitting positions, state of alertness (awake or asleep) and CSF pressure variation on TEOAE features were studied. None of these factors affected TEOAE amplitude. In 2 subjects, TEOAE amplitude increased considerably during the night while remaining stable in 7 subjects during daytime sleep. This may be due to circadian variations of TEOAE amplitude.

Acoustic Stimulation↗

Transiently evoked otoacoustic emission amplitudes change with changes of directed attention.

The effect of a visual and of an auditory task on the cochlea was studied by transiently evoked otoacoustic emissions (TEOAEs). TEOAE amplitude decreased during visual and auditory attention for all 13 subjects tested. The decreased TEOAE activity was noted predominantly within the 960 to 1920 Hz range during visual attention and within the 1920-2880 Hz range during auditory attention. Selective attention, by way of the olivocochlear medial efferent system, modifies cochlear micromechanical properties. Visual and auditory attention act on different areas of the cochlear partition.

Adult↗

Cleft larynx: management and one-stage surgical repair by anterior translaryngotracheal approach in two children.

Cleft larynx is a rare congenital anomaly which is now being reported with increasing frequency. It is characterized by a midline posterior defect. Two children underwent laryngeal cleft repair by an anterior translaryngeal approach. Tracheotomy was avoided and closure of the anterior laryngofissure was carried out over the nasotracheal tube. The patients were cared for in a pediatric intensive care unit until extubation. Extubation was performed on day 8. The older child had few functional problems and did well whereas the younger child did poorly. In this latter case, the initially successful surgical result was impaired by post-operative aspiration, due to numerous possible factors: gastroesophageal reflux secondarily controlled by Nissen fundoplication, disturbed swallowing as a result more of the cleft repair work than of the surgical approach, or else immaturity of the suction-swallowing reflex.

Child, Preschool↗

Role of long-term stenting in treatment of pediatric subglottic stenosis.

Twelve cases of childhood subglottic stenosis diagnosed either acquired or congenital were treated using an endolaryngotracheal Montgomery T-tube. Stenting lasted on average 5.6 months. Tracheotomy closure was possible in 75% of cases on average 15.3 months after diagnosis. Tube-linked complications involved the child pulling out, forward migration of the tube out, lower tracheal migration of the tube, clogging and the formation of granulation tissue at its superior extremity. Comparison of outcomes with those for laryngeal surgery (cricoid split, laryngotracheal reconstruction) found in the literature, suggests that long-term T-tube stenting is the optimal treatment for subglottic stenosis where tracheomalacia precludes laryngeal surgery.

Airway Obstruction↗

Sleep and active cochlear micromechanical properties in human subjects.

In this paper the effect of sleep on the cochlea is studied by transiently evoked otoacoustic emissions (TEOAEs). Amplitude increases considerably (e.g., 4 dB) and the effect of a contralateral noise on the TEOAEs decreases during the night. These modifications can be related to sleep, although there is no link to electroencephalographic sleep stage. During sleep onset, the effect of contralateral noise disappears: this could correspond to a functional rest of the auditory pathway during that period.

Acoustic Stimulation↗

[Treatment of recurrence of pleomorphic adenomas of the parotid gland].

This is a retrospective study of 10 patients who underwent surgery for a first or multiple recurrence of pleomorphic adenoma (P.A.). Recurrence may come more than 10 years after an initial episode. During initial surgery, the risk of recurrence is related to pre-operative dissemination and to failure to identify tumoral prolongations in the parotid gland. Recurrence is generally multifocal. In 2 cases, carcinoma developed in association with P.A. Treatment of benign recurrence is surgical: it consists of totalizing the previous parotidectomy. If the previous parotidectomy has been total, tumorectomy is carried out. In all cases, surgery preserves the facial nerve trunk.

Adult↗

Variability of the influence of a visual task on the active micromechanical properties of the cochlea.

The effect of a visual task on the active micromechanical properties of the cochlea studied by the evoked otoacoustic emissions (EOAEs) has been the subject of only one published study (Brain Research, 44 (1988) 380-383). In order to examine the reliability of this effect, a similar study has been run on 16 subjects. A significant decrease in EOAEs during a visual task was obtained for 3 subjects. The two subjects whose decrease was the most significant were tested again one month later and the same effect was found. This striking interindividual variability is discussed in terms of olivo-cochlear neuronal excitability.

Acoustic Stimulation↗

[Effect of attention on audition. Contribution of the study of the olivocochlear efferent system].

It is possible by studying the Evoked Otoacoustic Emissions (EOAEs) to detect an effect of selective attention on the cochlea. The authors present the main data of the literature and the results of their works. They show an effect of visual attention as well as auditory attention on the EOAEs. This effect is not the same whether attention is visual or auditory. There is a result of selective attention as early as the cochlear level.

Attention↗