Perilymphatic fistula induced by barotrauma.

The association between diving, barotrauma, and the production of perilymphatic fistula has been known for almost 20 years. Forty-eight cases of round and oval window fistulas following diving have been reviewed and essentially corroborate previous findings. Any patient with a history of diving and subsequent sensorineural hearing loss within 72 hours should be suspected of having a round or oval window perilymphatic fistula and surgical exploration and closure of the fistula should be undertaken. Patients who have a loss of hearing, vertigo, nausea, or vomiting following a decompression dive should be re-compressed and if symptoms do not clear, exploration should be performed. Surgical treatment should be executed as soon as possible after the diagnosis is suspected for the best possible results.     

Perilymphatic fistula in the guinea pig

Clinical reports on perilymphatic fistulae (PLF) of the round window membrane (RWM) have shown different degrees of hearing loss. However, the hearing can also be entirely unaffected. Experimentally induced PLF of the RWM in animals showed results similar to those of the clinical reports, although some researchers have concluded that perforation of the RWM per se does not necessarily induce significant hearing loss. The purpose of the present study was to clarify if, and how, PLF of RWM in the guinea pig actually affects the auditory action potentials. During 1 h of observation following perforation of the RWM, the immediate and continuous effect of the PLF was evaluated. In more than 50% of the animals, different amounts of threshold shift were obtained. In another group of guinea pigs an attempt was made to clarify the findings by reducing the cerebrospinal fluid pressure before perforating the RWM.     

Perilymphatic fistula: a New Hampshire experience

Thirty-five patients with perilymphatic fistulas (PLFs) are presented. Of this group of 35 patients (39 ears), 4 patients did not have fistulas that could be observed with certainty but were presumed to have fistulas by virtue of their excellent response to surgical repair. Our case reports provide examples of the great variety and possible classifications of presentations and symptom complexes that lead one to suspect the diagnosis of perilymphatic fistula. Comments on diagnostic and therapeutic modalities and on postoperative care and counseling are included. The age range of patients in our series is 3 to 67 years. Four patients are under age 20, and an additional three patients probably developed their symptoms prior to age 20 but presented later. Twenty-three (79%) of 29 patients with spontaneous PLFs began having symptoms closely related to some event involving physical or mechanical stress, and a high percentage (76%) had symptoms aggravated by physical stress. Six are believed to have fistulas of congenital origin. There is a sibling pair and a mother and son in the series; these four people had bilateral fistulas.     

Perilymphatic fistula in children with preexisting sensorineural hearing loss

Progression of preexisting sensorineural hearing loss (SNHL) in infants and children has been considered an indication for fistula exploration: is this approach warranted? On exploring 36 middle ears in 26 such children, we found a perilymphatic fistula (PLF) in four ears (11%). Although there was radiographic evidence of inner-ear deformity in one half of these children, a definite fistula was found in only four of 18 radiographically abnormal ears explored (22%). Even in the four patients with a history of an “event” that could implicate a fistula such as exertion or barotrauma, a fistula was found in only one. There are a number of possible causes for progression of a preexisting SNHL, and surgical exploration of the middle ear should not be recommended on the basis of progression alone. Instead, exploration for a suspected PLF should be strongly considered when there is also a history of an “event,” and/or radiographic evidence of inner-ear abnormalities. Even under these conditions, one should be aware that fistulae are not likely to be found.     

Perilymphatic fistula in pediatric patients with a preexisting sensorineural loss

A specific group of 28 children (38 ears) with a preexisting sensorineural hearing loss (SNHL) was studied to determine if a perilymphatic fistula (PLF) was the cause of a progression in their hearing loss. A PLF was identified surgically in six of these ears, but there was no evidence of any defect found in 32 ears. The symptoms shared by the cases in which a fistula was found included a traumatic event (including exertion), CT scan evidence of inner ear defects, hearing threshold decreases of 25 to 30 dB, and vertigo or postural instability.     

Perilymphatic fistula: differential diagnosis from Menière's disease

Records of 77 patients who had surgically proven perilymphatic fistula (PLF) from 1979 through 1988 were reviewed. During this period, 16 patients had a fluctuating hearing loss in association with spells of vertigo. Ten of these patients had been diagnosed as having Menière's disease by at least one otolaryngologist before exploration for PLF. Audio-vestibular functions were compared between these PLF patients and those with classic Menière's disease. The following factors are associated with a high incidence of PLF: (1) Low frequencies hearing loss which has father deterioration within few days; (2) A rapidly fluctuating low frequencies hearing loss with wide variability; (3) Very long duration of positional nystagmus; (4) Absence of canal paresis. PLFs often mimicked Menière's disease, although these patients did not have classic Menière's symptoms. This study emphasizes this overlap.     

Perilymphatic fistula following trans-tympanic trauma: a clinical case presentation and review of the literature

The perilymphatic fistula is constituted by an anomalous connection between the perilymphatic space and the middle ear. The principal accuses are to be sought in the intracranial pressure increasement, cranial traumas, barotraumas, congenital anomalies, trans-tympanic traumas, etc. Stapes's dislocation in the vestibule and the fracture of the platina are the most frequent pathogenic mechanisms. In clinical practice, the diagnosis remains a problem rather debated, even if the clinical pattern, the laboratory investigations, the diagnostic images and the tympanic exploration, all together can confirm, in the majority of the cases, the diagnostic suspect. This article presents a clinical case of a transtympanic trauma with perilymphatic fistula caused by a foreign body. The peculiarity of this case must be set in relation with both the aetiopathogenesis of the labyrinthine lesion and the severity of the symptomatology caused by it.     

Perilymphatic fistula: an unusual cause of of Méniére's syndrome in a prepubertal child

Non-traumatic, spontaneous perilymph fistula of the oval window is an unusual cause of Ménière's syndrome in a child. In this case, all of the audio-vestibular criteria for a diagnosis of Ménière's syndrome (or clinical endolymphatic hydrops), including a temporary threshold shift after the glycerol test, were demonstrated. At exploratory tympanotomy, a perilymph fistula, demonstrated at the footplate margins was plugged with fat. There was significant immediate postoperative and six-month follow-up improvement in perception of pure tone, speech reception threshold (SRT) and discrimination score.     

Perilymphatic gusher and stapes surgery. A predictable complication?

The cases of 3 patients who had 'perilymph gushers' following stapes surgery are reported. The similarities in their clinical histories and examinations are discussed. All 3 were males and had progressive mixed deafness presenting in early childhood. Polytomography revealed anomalies in both the vestibule and internal auditory meatus in 1 patient; the stapedial reflex was unexpectedly large in all 3. Further preoperative evaluation of these features in other patients and patients affected by the X-linked deafness syndrome is indicated in order to assess the validity of the above criteria.     

Low-frequency hearing loss after spinal anesthesia. Perilymphatic hypotonia?

Audiological tests were conducted on 34 patients before and after undergoing an operation under spinal anesthesia. One of these patients developed a considerable unilateral hearing loss in the low-frequency range, which persisted until an epidural blood-patch was given. Unexpectedly, we also found a general small significant threshold shift at 500 Hz, which has never before been described in the literature. The biological mechanism is discussed and the results suggest that the explanation of the hearing loss could be an endolymphatic hydrops resulting from perilymphatic hypotonia due to loss of liquor, during and after the spinal anesthesia.     

Perilymphatic gushers: myths and reality

The term perilymphatic gusher refers to the escape of inner ear fluid under pressure through the oval window, generally during surgery for otosclerosis. It also appears during cochlear implantation. We reviewed the morphological aspects of the temporal bone of patients with perilymphatic gusher. The cases of three patients with the features of cerebrospinal fluid leaks under pressure cited in the literature are described. Anatomic and pathologic features are discussed in the light of knowledge of molecular genetics.     

Perilymphatic fistula of the round window after whiplash injury: another cause of inner ear conductive hearing loss

Perilymphatic fistula is usually associated with sudden or fluctuating sensorineural hearing loss. We present a case of whiplash injury in a patient who showed conductive hearing loss at low frequencies due to a perilymphatic fistula occurring in the round window. Although no middle ear pathology was found, the symptoms and laboratory findings were mimicking the so called “third mobile window” phenomenon, but without the presence of inner ear dehiscence. Following early surgical exploration with patching of the round window the hearing was restored and the patient was free of symptoms.     

Perilymphatic concentration of gentamicin administered intratympanically in guinea pigs.

Intratympanic gentamicin therapy has recently become popular for Meniere's disease, although the administration protocol remains controversial. To date, few studies have been conducted regarding the pharmacokinetics of drugs administered intratympanically. We measured gentamicin concentration in the perilymph close to the round window membrane using a microdialysis technique. A bolus of 0.5 mg gentamicin was put on the round window membrane or a clinically used solution of 5 mg gentamicin was placed in the tympanic bulla of guinea pigs. After 56 +/- 21 min of bolus administration, gentamicin concentration reached a maximum level of 2900 +/- 1200 microg/ml and then decreased, with a half-life of 117 +/- 47 min, characteristic of the kinetics expected with a one-compartment model. With solution administration, the maximum concentration did not differ, but the time to the maximum concentration and the half-life in the perilymph were longer, compared with the results of bolus administration. Our results suggest that even solution administration of gentamicin, which is simple and repeatable, provides a sufficient, stable and continuous supply to the perilymph.     

Perilymphatic effusion as a complication of otosclerosis

INTRODUCTION: Stapes gusher means the leakage of perilymphatic liquid when opening the perilymphatic cistern. The perilymphatic liquid with a high pressure gushes with a great flow out of the cistern when the stapedotomy is executed. Otosclerosis surgery sometime brings to light abnormal contact between the inner ear and the sub-arachnoidian spaces in patients who didn't presented ear malformations. It's a very rare event (1/1000) which is different from a much more common and more moderate form of perilymphatic liquids high pressure (1/200). About 4 clinical observations, we compared our experience with other authors in specialist reviews. PURPOSE OF THE STUDY: About four observations, we confronted our experience with that of the literature. MATERIAL AND METHODS: Retrospective study between 1971 and 1998. It was about 3 males and 1 female, without antecedent except one of them who had been operated 5 years before for the opposite ear without gusher but without good audiometric result. They presented a conductive deafness with no answer of the stapedial reflex. We had 4 geysers during the platinotomia which were sealed with some connective tissue. RESULTS: Two patients had a post operative complete sensory hearing loss, one, a sensitive decline of the conduction thresholds (average 50 dB), the last one kept his bone conduction level with a mild sensory hearing loss. The most recent case had a scanner preoperatively which had not shown abnormality except for the focus of otosclerosis. DISCUSSION: Perilymphatic gusher is an unpredictable event that can not be diagnosed before the surgery, nether with clinical facts nor radiological elements. This involves serious consequences concerning not only the continuation of the surgical operation and the prognostic of the hearing but also concerning the danger of secondary meningeal infections. The best way to proceed in case of favourable cases consists in fitting the ossicular prothesis into the stapedotomy, when it's not to wide. Pieces of muscle can be used in some cases, taped on with biologic glu. Various techniques are used to lower the pression of the cerebrospinal liquid: hypertonic solutes, diuretic drugs, lumbar diversion. In all cases, it is necessary to start a wide spectrum antibiotic treatment and a vaccination against pneumococcis. CONCLUSION: The surgeon has to know all the option of the treatment when confronted with this situation in order to try to avoid tricky defect of the inner ear.