[Vestibular dysfunction in the postpartum period following gestosis]

The state of the vestibular system was evaluated in 30 postpartum women following gestosis and 25 controls after uncomplicated pregnancy. Examination using the electronystagmographic technique failed to reveal spontaneous nystagmus (Ny) in the latter group whereas 13.3% and 30% women of the former group had it with the eyes open and closed respectively. Provocative functional tests significantly improved detectability of Ny. Hyperventilation was associated with Ny in 80% and 12% of the women after complicated and uneventful pregnancy respectively while orthostatic test revealed Ny in 63% and 12% of them. Active head rotation with closed eyes produced well-apparent experimental Ny in women of both groups, but it was significantly more pronounced in the former one. Post-gestosis women displayed markedly impaired reaction in vestibular-ocular reflex suppression test. It is concluded that 80% of the women with complicated pregnancy exhibited vestibular dysfunction of central origin in the postpartum period.

[High-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis.]

The goal of the present study was to explore high-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis. The guinea pigs were randomly divided into four groups (group 1, 2, 3 and control group, n=20). The animals of treated groups received gentamicin subcutaneously (50 mg/kg per day) for 1 week (group 1), 2 weeks (group 2) and 3 weeks (group 3), respectively. The animals of control group were administered with equal volume of saline subcutaneously. Videonystagmography (VNG) evoked by ice water or high-frequency rotations, and vestibular evoked potential (VsEP) evoked by low- and high-frequency rotations were recorded after the administration. After VNG and VsEP were examined, the cristae of the horizontal semicircular canals were prepared for scanning and transmission electron microscopy. The results are as follows: (1) In VNG examination, after ice water stimulation, no obvious nystagmus was observed in the animals of group 3, and there was no significant difference in nystagmus frequency and duration among group 1, 2 and control group (P>0.05). After high- frequency rotations, no obvious nystagmus was yet observed in the animals of group 3. There were significant differences in the nystagmus frequency and duration of the VNG waves between the experimental group 2 and control group (P<0.01), and no difference was found between group 1 and control group (P>0.05). (2) In VsEP examination, there was no significant difference in the parameters of VsEP among group 1, 2 and control group (P>0.05), and VsEP was not observed in group 3 after low-frequency rotations. After high- frequency rotations, compared with control group, the latencies and amplitudes of P1 and P2 in group 2 significantly decreased (P<0.01), while no changes were found in group 1 (P>0.05). Group 3 had no response of VsEP to high-frequency rotations. (3) Electron microscopy was used to observe the crista hair cells of the four groups. In control group, the hair cells were normal. In group 1, almost normal appearance with slight edema of the hair cells was shown. In group 2, some hair cells in the central top of the crista necrosed, but other hair cells in the peripheral area showed normal appearance. In group 3, vestibular hair cells were entirely impaired or necrosis. These results show gentamicin selectively induces high-frequency rotation sensation function damage of the crista of the horizontal semicircular canal. The damage is concentrated on the central top area and then subsequently extended to the peripheral area of vestibular crista. It can be inferred that the hair cells in the central top area of the crista are involved in high-frequency rotation vestibular perception.

Age-dependent effects of RPE65 gene therapy for Leber's congenital amaurosis: a phase 1 dose-escalation trial

BACKGROUND

Gene therapy has the potential to reverse disease or prevent further deterioration of vision in patients with incurable inherited retinal degeneration. We therefore did a phase 1 trial to assess the effect of gene therapy on retinal and visual function in children and adults with Leber's congenital amaurosis.

METHODS

We assessed the retinal and visual function in 12 patients (aged 8-44 years) with RPE65-associated Leber's congenital amaurosis given one subretinal injection of adeno-associated virus (AAV) containing a gene encoding a protein needed for the isomerohydrolase activity of the retinal pigment epithelium (AAV2-hRPE65v2) in the worst eye at low (1.5 x 10(10) vector genomes), medium (4.8 x 10(10) vector genomes), or high dose (1.5 x 10(11) vector genomes) for up to 2 years.

FINDINGS

AAV2-hRPE65v2 was well tolerated and all patients showed sustained improvement in subjective and objective measurements of vision (ie, dark adaptometry, pupillometry, electroretinography, nystagmus, and ambulatory behaviour). Patients had at least a 2 log unit increase in pupillary light responses, and an 8-year-old child had nearly the same level of light sensitivity as that in age-matched normal-sighted individuals. The greatest improvement was noted in children, all of whom gained ambulatory vision. The study is registered with ClinicalTrials.gov, number NCT00516477.

INTERPRETATION

The safety, extent, and stability of improvement in vision in all patients support the use of AAV-mediated gene therapy for treatment of inherited retinal diseases, with early intervention resulting in the best potential gain.

FUNDING

Center for Cellular and Molecular Therapeutics at the Children's Hospital of Philadelphia, Foundation Fighting Blindness, Telethon, Research to Prevent Blindness, F M Kirby Foundation, Mackall Foundation Trust, Regione Campania Convenzione, European Union, Associazione Italiana Amaurosi Congenita di Leber, Fund for Scientific Research, Fund for Research in Ophthalmology, and National Center for Research Resources.

[Clinical features of multiple canal involvement in benign paroxysmal positional vertigo]

OBJECTIVE

To describe a series of patients with multiple canal involvement in benign paroxysmal positional vertigo (BPPV), with respect to diagnosis and management.

METHODS

Ninety-five individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of multiple positional nystagmus as confirmed by video-oculographic examination. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal.

RESULTS

Ninety-five patients showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV. Fourteen patients (14.7%) had bilateral canal BPPV. Six patients had bilateral posterior canal. Six patients had bilateral horizontal canal, and two patients had bilateral anterior canal. Fifty-three patients (55.8%) had torsional, up-beating nystagmus with down-beating nystagmus, which suggested possible affected both of posterior and anterior canals. Twenty patients (21.1%) had torsional up-beating nystagmus and horizontal direction nystagmus, which suggested possible affected both of posterior and horizontal canals. Five patients had down-beating nystagmus with horizontal nystagmus, which suggested affected both of anterior and horizontal canals. Three patients had torsional up-beating with down-beating and horizontal nystagmus, which suggested possible affected multiple canals. Treatment given to the patients varied according to the canal affected, started with the canal that elicited a strong positional nystagmus and vertigo, and 93.7% (89/95) of patients were symptom free or improved.

CONCLUSIONS

It has been found that multi-canal BPPV is not a rate observation in clinic, and most of them affected posterior and anterior canals. Treatment of multi-canal BPPV can be effective using repositioning maneuver.

[The clinical value of dynamic posturography in the peripheral vertigo]

OBJECTIVE

To explore the clinical value of dynamic posturography in the diagnosis of peripheral vertigo.

METHOD

One hundred and sixty peripheral vertigo patients with full clinical documents in vertigo clinic of our hospital from May 2007 to May 2008 were retrospectively analyzed in this study. All the patients firstly underwent the inspection of static and dynamic posturography and then were subjected to caloric test using videonystagmography. The results were conducted a comparative analysis. Surface of the statokinesigram (SSKG) was selected as assessment parameter of static posturography. The result of sensory organization test (SOT) were selected as assessment parameters of dynamic posturography. The unilateral weakness was selected as assessment parameter of caloric test. Twenty normal subjects were selected as control.

RESULT

Among the 160 cases with peripheral vertigo, results of SOT in dynamic posturography were abnormal in 144 cases, with a sensitivity of 90.0%; caloric test was abnormal in 110 cases, with a sensitivity of 68.8%; static posturography was abnormal in 76 cases, with a sensitivity of 47.5%. There existed a statistically significant difference between dynamic posturography and caloric test or static posturography. There were 40 patients (25.0%) who had normal caloric test results in which dynamic posturography findings were abnormal. Among the 20 cases of normal people, results of SOT in dynamic posturography were abnormal in only one case (5.0%).

CONCLUSION

With its superior sensitivity and specificity, dynamic posturography has been an objective and reliable approach in the diagnosis of peripheral vertigo. It can help to confirm the presence of abnormalities in some peripheral vertigo patients whose caloric results are normal.

The development of binocular function in infancy

Binocular function in infancy can be assessed by means of the visual evoked potential (VEP) induced by a dynamic random dot pattern which alternates between a binocularly correlated and an anticorrelated state. A VEP time-locked to the alternation can only be produced by binocular interaction in the cortex. This interaction becomes detectable at around three months of age. Optokinetic nystagmus (OKN) in monocular viewing becomes symmetrical in nasal and temporal directions around the same age. Animal analogues and clinical cases suggest that this may also be an indicator of cortical binocularity. These techniques may be applicable to clinical assessment of binocular function in young infants.

Optokinetic nystagmus

Optokinetic nystagmus (OKN), one of the phenomena examined in order to analyse balance and sight disturbances, is manifest in two types: The cortical and the subcortical OKN. Their main distinction is in the velocities. They are also transmitted via different nervous pathways. This paper introduces a method to record the OKN of the two eyes individually. While joint OKN-recordings of both eyes together may mask disturbances of one eye, the separate recordings could reveal them. The discussion deals with applications of OKN-examination to ergophthalmology e.g. in cases of industrial solvent intoxications.

A historical vignette (13). "Who are you, Nystagmus"? A semantic and historical approach

"Who are you, Nystagmus?" A semantic and historical approach. Initially, the need to name nystagmus was logically satisfied by the use of the metaphor of a galloping horse, "hippus". Later, nictatio, oeil d'hypocrite and souris embodied the presumed connection between blinking and the rhythmic involuntary movements of the eyeball. Blinking was also considered by Boissier as an inseparable companion of the unsteadiness of the eyeballs. Since drowsiness is a good example of a state accompanied by blinking, it makes sense, strange though it may seem, to use the Greek word for drowsiness, "nustagmos", to refer to the instable movement of the eyeballs. From a poetic point of view and in the light of the rapid phase of the phenomenon, nystagmus can be thought of as "a modern Sisyphus, the operator of the eternal return".

Converting apogeotropic into geotropic lateral canalolithiasis by head-pitching manoeuvre in the sitting position

Liberatory treatment of lateral canalolithiasis is more effective for the geotropic, than for the apogeotropic forms and, therefore, it is worthwhile attempting to convert the apogeotropic forms into the geotropic forms. In 36 cases of apogeotropic lateral canalolithiasis, one to five Head-Pitch Manoeuvres were performed in the sitting position (Head-Pitch Test) in the attempt to transform apogeotropic into geotropic lateral canalolithiasis. The Head Pitch Test was performed by a quick 60 degrees forward-flexion and a slow maximal backward-extension of the head. The Head-Pitch Test was effective in 36.1% of cases, less than the repeated Head-Rolling in the supine position, but it was always well tolerated by patients. The quick 60 degrees forward-flexion of the head can evoke a horizontal nystagmus beating towards the healthy side in apogeotropic lateral canalolithiasis and towards the affected side in geotropic lateral canalolithiasis (Bow Nystagmus). Slow backward-extension of the head can evoke a horizontal nystagmus beating towards the affected side in apogeotropic lateral canalolithiasis and toward the healthy side in geotropic lateral canalolithiasis (Lean Nystagmus). Conversion from apogeotropic to geotropic lateral canalolithiasis by the Head-Pitch Test was effective when Bow and Lean Nystagmus changed directions or when the Head-Pitch Test evoked Bow Nystagmus toward the affected side and Lean Nystagmus toward the healthy side. Conversion occurred in 10 patients during the 60 degrees forward-flexion of the head. In contrast, in 3 patients, it occurred during extension of the head, when a "Lean Nystagmus" toward the healthy side appeared. In addition, Pseudospontaneous Nystagmus and Positioning Nystagmus that arose when the patient moved from the sitting to the supine position changed direction or were evoked ex-novo, both directed toward the healthy side. In all cases, Pagnini-McClure diagnostic manoeuvre confirmed the transformation with a Positional Paroxysmal Horizontal Geotropic Nystagmus, which was more intense when the affected ear was brought down. The Head-Pitch Test can be used as the method of choice to transform apogeotropic into geotropic lateral canalolithiasis. However, anterior flexion of the head in the geotropic forms must be avoided since involuntary and harmful transformations from the geotropic into the apogeotropic form can occur, moving otoliths towards the anterior arm and cupula.

Alternobaric vertigo--really a hazard?

OBJECTIVE

To determine the prevalence of alternobaric vertigo (AV) in sport divers and to find out whether AV led to dangerous situations underwater. Furthermore, to examine whether objective neurootologic tests are associated with the manifestation of AV.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Sixty-three sport divers with an average diving experience of 10 years and 650 dives were questioned regarding their medical and diving history and the manifestation of vertigo during diving.

METHODS

Microscopic otoscopy, tympanometry, stapedius reflexes, hearing threshold for air and bone conduction, caloric video-oculography including analysis of the slow-phase velocity of the nystagmus, acoustic brain stem responses, and magnetic resonance imaging were performed to find possible differences between divers with and without AV.

RESULTS

We found 17 divers with AV (27%). There was no significant difference in all measured parameters apart from sex and history of middle ear equalization difficulty in divers with AV. Ten (59%) of 17 female divers and 7 (15%) of 46 male divers experienced AV, representing a significant sex difference (p < 0.001). Correlation with our divers' outpatient clinic revealed that female divers had a significantly higher incidence of middle ear equalization disorders which could be an explanation for the predominance of female divers with symptoms of AV. None of the divers reported any dangerous or life-threatening situations following AV. Whether AV leads to dangerous situations underwater remains unclear, but this hypothesis is not supported by our data.

CONCLUSION

Alternobaric vertigo is a common finding in divers. In our study group, female divers had a four-time higher risk to suffer AV. Our data do not support the thesis that AV is a life-threatening condition.

Screening for vestibular disorders: a study of clinicians' compliance with recommended practices

BACKGROUND

Dizziness and vertigo are very common patient complaints encountered by clinicians in both primary as well as specialty care in otolaryngology and neurology. Vestibular impairment is an underlying cause in as many as 45% of people complaining of dizziness. Most causes of vestibular impairment can be effectively treated; however, the diagnosis is frequently missed. The aim of this study was to examine clinical assessments used by providers in evaluating dizzy patients in outpatient clinics and the emergency department.

MATERIAL/METHODS

Computerized medical records of all patients receiving an ICD-9 diagnosis code for dizziness, including benign paroxysmal positional vertigo, Meniere's disease, and vestibular hypofunction over a six-month period at the Atlanta VA Medical Center were reviewed.

RESULTS

476 patients were identified and of these, 157 patients were included. Over two-thirds of providers (69%) used the patient's description of the dizziness for identifying the cause; however, significant variability was evident across disciplines, ranging from 84% of audiologists asking for a description of the dizziness to only 33% of geriatricians asking. 89% of providers did not evaluate a patient for BPPV by examining for positional nystagmus. Primary care clinicians referred 22% of dizzy patients to a specialist (neurotologist), geriatricians referred 17%, and emergency physicians referred only 16%.

CONCLUSIONS

Dizzy patients were not routinely screened for vestibular impairment based on available recommended practices, likely contributing to underdiagnosis and treatment. Results indicate a need for effective dissemination of guidelines to improve health care quality, increase awareness of medical risks, and enhance patient access to appropriate treatment.

[Pathologies of the cervical spine anatomy as a possible cause of young patients vertigo]

Vertigo occurs in many diseases, especially in older people. It is a specific diagnostic problem in young people. In the paper, 86 young patients with incidental vertigo were clinically assessed. Electronystagmography, eye-tracking pattern test, optokinetic test and cervical spine X rays were used in examination. The results were compared with the control group of young and healthy people and also with the older patients group with degenerative changes of the cervical spine. In the examined group the disturbances of physiologic cervical lordosis were found in 33.8% and positional nystagmus in 23%. The vestibular tests and hearing were frequently normal. These results suggest that disturbances of physiologic cervical lordosis may be the cause of balance disturbances.

[Decrease of the slow phase velocities of postrotatory nystagmi as a result of the otolith organs stimulation]

Intact pigeons were rotated in darkness in a horizontal plane at various orientations relative to axis of rotation, which passed between labyrinths, or was displaced relative to them. Trapezoidal (tests 1) and triangular (tests 2) rotation programs were used. In the tests 1, positive and negative angular accelerations were separated by two-minute periods of rotation with constant angular velocity. Such periods were absent in the tests 2. Results of the canal-otolith interactions in the tests 1 and 2 were different only in postrotatory nystagmi: the peak velocities of the slow phases decreased in both postrotatory nystagmi in the tests 1, but only in one of them in the tests 2. Apparently, at oppositely directed postrotatory nystagmi, decrease of peak velocities in the tests 1 is provided with different mechanisms. At one of them the decrease of nystagmus velocity reflects a result of a summation of canal and otolithic signals on the interneurones of the semicircular canal reflex arches, whereas at another one it is related with long-lasting activity imbalance of these interneurones which is supported by otolithic afferentation during rotation at constant angular velocity.

[Frequently occurring forms of dizziness and their treatment]

Dizziness is not a unique clinical picture, but rather is the unspecific symptom of numerous diseases. Dizziness always develops when the real incoming vestibular, visual and somatosensory information contradict each other and the expected input signals. Disorders of the vestibular apparatus are the most frequent cause of dizziness; in contrast, cervicogenic causes play a secondary role. Dizziness syndromes usually have a favourable prognosis and can be successfully treated.

A comparison of two different techniques for oculomotor torque reduction

PURPOSE

To compare the results of two different surgical techniques: 'Cüppers technique', in which the torque of oculomotor rectus muscles is reduced by suturing the muscle to the globe in the posterior half of the globe; and 'Y-split recessions', in which the muscle torque is reduced by Y-splitting the rectus muscles, and reattaching the two halves at an angle to each other.

METHODS

We carried out a retrospective analysis of the outcome of surgery on 100 patients with infantile esotropia.

RESULTS

Both techniques show a sufficient reduction of strabismus angle variability, and minimal and maximal strabismus angle.

CONCLUSIONS

Both techniques achieve satisfactory results. In addition, the Y-split technique allows for accurate control of the muscle torque and requires no access to the posterior half of the eye, which can facilitate the surgical approach. For a reduction in muscle torque, the Y-split recession is a good alternative to the established Cüppers technique.

Vertical component of the caloric response, including a caloric second phase provoked by positional change: a preliminary report

We measured the horizontal and vertical components of caloric nystagmus in 120 ears of 60 vertiginous patients who had moderate to vigorous caloric first-phase response in both ears, no spontaneous nystagmus, and no severe disorders in the central nervous system. We provoked a caloric first phase in the supine position with 5 ml of water at 20 degrees C for 15 seconds. We provoked a caloric second phase by changing the position of a patient from supine to sitting after the end of the first phase. The horizontal component of the caloric second phase was recorded in 108 of 120 ears (90%). The vertical component was recorded in 57 of 120 ears (48%) during the caloric first phase and in 51 of 120 ears (43%) during the caloric second phase. We suspected that the vertical component of the caloric first phase was mainly due to the inhibition of the anterior semicircular canal.

Pathological localization of so-called posterior canal BPPV

OBJECTIVE

Based on the hypothesis that the origin of nystagmus is from the posterior canal (PC), the nystagmus in the head hanging and sitting position should be mirror images. To clarify the anatomical origin of positioning nystagmus in BPPV patients, we analyzed the positioning nystagmus of benign paroxysmal positioning vertigo (BPPV) patients three-dimensionally.

METHODS

Twenty-six patients with BPPV participated in this study. The positioning nystagmus was recorded in complete darkness from the patient's left eye by means of an infrared CCD camera. We performed three-dimensional analysis of nystagmus using video image analysis system (VIAS). Subsequently, the rotation axis of the 3D eye movements of the positioning nystagmus was calculated.

RESULTS

Among the 26 patients tested, 20 patients demonstrated the axes of nystagmus in good or relatively good alignment to the PC axis. However, in 11 of these 20 patients there was poor alignment of the axis of nystagmus in the sitting position to the PC axis. In addition, six patients showed axes of nystagmus with poor alignment to the PC in the head hanging position. Among them, two patients exhibited axes of nystagmus in good alignment with the anterior canal, in spite of diagnosis of these patients as PC BPPV by experienced examiner based on the positioning nystagmus test.

CONCLUSION

These results demonstrated that only one-third of patients who were diagnosed as BPPV, could be diagnosed as true BPPV which originates from a PC pathology. Besides the possibility that the pathology may originate from the AC, it is still unclear which part of the inner ear may be the candidate site of origin of the pathology of BPPV in the other 15 patients.

[Benign paroxysmal positional vertigo with and without manifest positional nystagmus: an 18-month follow-up study of 70 patients]

BACKGROUND

In this follow-up study of approximately 18 months we assessed parameters of medical management in a sample of 70 patients suffering from benign paroxysmal positional vertigo.

METHODS

Apart from demographic data, we evaluated the time interval from the appearance of the first symptoms until a diagnostic positional manoeuvre was performed, the efficacy of liberatory manoeuvres, the prescription of medication, the use of technical diagnostic resources and the relapse rate.

RESULTS

None of the patients had received a diagnostic positioning test until then. Moreover, in one out of three cases a further unnecessary technical diagnostic procedure was carried out. There was a tendency for the right labyrinth to be more frequently affected, a fact that was statistically independent from age and sex, as well as from overall prognosis, which was characterized by a 15.6% recurrence rate. All patients with manifest positional nystagmus were successfully treated: 87.2% immediately after the repositioning manoeuvre and the rest within 10 days by self-performing Brandt-Daroff exercises. Our retrospective analysis revealed that, given a normal neuro-otological examination, a typical medical history without manifest positioning nystagmus leads safely to the correct diagnosis.

CONCLUSION

The delay between the onset of symptoms and the diagnosis of BPPV is very often unduly long. A focused medical history may be diagnostic even in the absence of nystagmus during the Dix-Hallpike manoeuvre.

Audiovestibular dysfunction in alcohol dependence. Are we worried?

PURPOSE

To study the audiovestibular function in patients of long-term alcohol dependence and compare these changes with social users of alcohol and complete abstainers.

MATERIAL AND METHODS

This was a prospective study of 20 randomly selected patients of long-term alcohol dependence fulfilling International Statistical Classification of Diseases, 10th Revision criteria of alcohol dependence. Audiovestibular function in this group was compared with social user of alcohol and complete abstainers.

RESULTS

Statistically significant elevations of thresholds were found at higher frequencies (4000 and 8000 Hz ) in the alcohol-dependent group (P < .001). Alcohol-dependent patients had elevated thresholds at 4 and 8 kHz. Brainstem-evoked response audiometry showed prolongation of latencies of waves I, III, and V alone with interpeak latencies of I-III and III-V. One third of alcohol-dependent patients had abnormal electronystagmographic (ENG) findings. Abnormal ENG findings were only seen in alcohol-dependent patients with vertigo. There was no significant correlation between duration of alcohol dependence and abnormal ENG.

CONCLUSIONS

Elevated thresholds at higher frequencies can be the only abnormality in alcohol-dependent patients. Presence of vertigo in alcohol-dependent patient may be associated with abnormal ENG findings. There is no correlation of duration of dependence and ENG abnormalities.