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Nystagmus is defined as rhythmic, most often involuntary eye movements. It normally consists of a slow (pathological) drift of the eyes, followed by a fast central compensatory movement back to the primary position (refixation saccade). The direction, however, is reported according to the fast phase. The cardinal symptoms are, on the one hand, blurred vision, jumping images (oscillopsia), reduced visual acuity and, sometimes, double vision; many of these symptoms depend on the eye position. On the other hand, depending on the etiology, patients may suffer from the following symptoms: 1. permanent dizziness, postural imbalance, and gait disorder (typical of downbeat and upbeat nystagmus); 2. if the onset of symptoms is acute, the patient may experience spinning vertigo with a tendency to fall to one side (due to ischemia in the area of the brainstem or cerebellum with central fixation nystagmus or as acute unilateral vestibulopathy with spontaneous peripheral vestibular nystagmus); or 3. positional vertigo. There are two major categories: the first is spontaneous nystagmus, i.e., nystagmus which occurs in the primary position as upbeat or downbeat nystagmus; and the second includes various types of nystagmus which are induced or modified by certain factors. Examples are gaze-evoked nystagmus, head-shaking nystagmus, positional nystagmus, and hyperventilation-induced nystagmus. In addition, there are disorders similar to nystagmus, such as ocular flutter or opsoclonus. The most common central types of spontaneous nystagmus are downbeat and upbeat, infantile, pure torsional, pendular fixation, periodic alternating, and seesaw nystagmus. Many types of nystagmus allow a precise neuroanatomical localization: for instance, downbeat nystagmus, which is most often caused by a bilateral floccular lesion or dysfunction, or upbeat nystagmus, which is caused by a lesion in the midbrain or medulla. Examples of drug treatment are the use of 4-aminopyridine for downbeat and upbeat nystagmus, memantine or gabapentin for pendular fixation nystagmus, or baclofen for periodic alternating nystagmus. In this article we are focusing on nystagmus. In a second article we will focus on central ocular motor disorders, such as saccade or gaze palsy, internuclear ophthalmoplegia, and gaze-holding deficits. Therefore, these types of eye movements will not be described here in detail.Unter einem Nystagmus versteht man rhythmische Augenbewegungen, die i. d. R. aus einer langsamen (ursächlichen bzw. pathologischen) Augendrift und einer schnellen kompensatorischen Rückstellbewegung (Rückstellsakkade) bestehen; die Richtung wird klinisch nach der schnellen Phase angegeben. Leitsymptome sind zum einen Verschwommensehen, „hüpfende oder laufende Bilder“ (Oszillopsien), verminderte Sehschärfe sowie manchmal Doppelbilder, die oft blickpositionsabhängig sind. Zum anderen können die Patienten, je nach Ursache, leiden unter 1. permanentem Schwankschwindel und Gangunsicherheit (wie beim Downbeat- [DBN] oder Upbeat-Nystagmus [UBN]), 2. Drehschwindel mit gerichteter Fallneigung (bei akutem Beginn) sowie 3. Lagerungsschwindel. Es lassen sich im Wesentlichen zwei Kategorien unterscheiden: 1. Spontannystagmus, d. h. ein Nystagmus, der in Geradeausblickposition auftritt, wie DBN oder UBN, und 2. verschiedene Nystagmusformen, die durch bestimmte Faktoren ausgelöst oder moduliert werden, wie Blickrichtungs-, Kopfschüttel-, Rebound-, Lagerungs-, hyperventilations- oder druckinduzierter Nystagmus. Daneben gibt es noch nystagmusähnliche schnelle Augenbewegungen wie Ocular Flutter oder Opsoklonus. Die häufigsten zentralen Formen eines Spontannystagmus sind DBN, UBN, infantiler Nystagmus, seltener sind Fixationspendelnystagmus, rein torsioneller, periodisch alternierender und See-saw-Nystagmus. Viele Nystagmusformen erlauben eine genaue anatomische Lokalisation, wie z. B. der DBN, der meistens auf einer beidseitigen zerebellären Flocculusläsion beruht oder der UBN auf einer Läsion im Mesenzephalon oder der Medulla oblongata. Beispiele einer Pharmakotherapie sind die Gabe von 4-Aminopyridin beim DBN und UBN, Memantin oder Gabapentin beim Fixationspendelnystagmus oder Baclofen beim periodisch alternierenden Nystagmus. Abschließend: in einem nachfolgenden Artikel werden in dieser Zeitschrift die häufigsten und klinisch relevanten zentralen Okulomotorikstörungen wie Sakkaden und Blickparesen, internukleäre Ophthalmoplegie oder Blickhaltedefekte dargestellt, sodass auf diese hier nicht detailliert eingegangen wird.

Benign paroxysmal positional vertigo (BPPV) is the most frequent form of vertigo seen in patients attending emergency departments. Leading symptoms are short attacks of vertigo provoked by head or body rotations. BPPV is caused by small calcium crystals, so-called otoconia, which are dislocated from the macula of the utricle mostly into the posterior semicircular canal. Free floating otoconia can move under the influence of gravity inside the semicircular canal (canalolithiasis) or adhere to the cupula (cupulolithiasis) causing displacement of the cupula. This results in positional nystagmus, whose directions and time courses are characteristic for the affected semicircular canal and the underlying cause. In recent years, however, a number of cases were reported, in which direction and times course of nystagmus differed from typical clinical findings. This may cause diagnostic problems.Der benigne periphere paroxysmale Lagerungsschwindel („benign paroxysmal positional vertigo“, BPPV) ist die häufigste Schwindelform, wegen der Patienten in die Notaufnahme kommen. Leitsymptom sind kurze Drehschwindelattacken, die bei Kopf- oder Körperdrehungen auftreten. Ursache eines BPPV sind Verlagerungen kleiner Kalzitkristalle, sog. Otokonien, von der Macula utriculi in einen, meist den hinteren Bogengang. Hier können sich die Otokonien unter Einwirkung der Schwerkraft frei im Bogengang bewegen (Kanalolithiasis) oder der Kupula anhaften (Kupulolithiasis) und zu deren Auslenkung führen. Die Schlagrichtungen der hierbei auftretenden Lagerungsnystagmen sind für den jeweils betroffenen Bogengang und die zugrunde liegende Ursache charakteristisch. Allerdings sind in den letzten Jahren eine Reihe von Nystagmen mitgeteilt worden, deren Schlagrichtungen oder Zeitverlauf sich von den typischen Lagerungsnystagmen unterschieden haben. Dies kann zu diagnostischen Problemen führen.

The correction of anomalous head posture associated with infantile nystagmus syndrome (INS) is carried out by the Kestenbaum procedure (KP) combining bilateral horizontal yoke muscle recession with resection of their antagonists or by the Anderson procedure (AP) which is confined to yoke muscle recession alone.To compare the results of highly dosed AP and KP for anomalous head turn (HT).The AP (2013-2019) and KP (2003-2013) were used as the exclusive procedures during the respective time periods. A highly dosed AP was performed in a case series of 33 consecutive orthotropic patients with INS and KP in 19 orthotropic patients with INS. Medians and ranges (min-max) in groups AP/KP were: age at surgery 7 years (4-44 years)/6 years (4-27 years), HT 32.5° (20-45°)/30° (17-40°) and surgery on each eye AP 13 mm (10-16 mm) (standard dose), KP 10 mm (6-12 mm) + 10 mm (6-12 mm) (mean 0.6 mm/°HT).The HT was diminished to 10° (-3-20°)/10° (-7-20°) ca. 3 months after surgery. At the late visit (8-153 months), the residual HT was 10° (0-20°)/10° (-27-30°). The HT was reduced by 67% (20-100%)/64% (14-100%) at the last control. A residual HT ≤15° was present in 79%/81% of cases (91% after AP ≥13 mm; n = 23) and HT ≤10° in 55%/57%, (65% after AP ≥13 mm). The maximum adduction/abduction towards the recessed muscles was 30°/30° (10-37°/15-45°) after AP and 32°/30° (10-40°/12-45°) after KP. An associated head tilt was not improved by the intervention. Mean binocular visual acuity increased by1 line in both procedures. After AP the mean increase was 1 line in children ≤6 years old and there was no increase in patients6 years of age.The effectiveness and success rates of AP and KP were similar with the dosing used. Less invasive surgery is an advantage in favor of AP as the primary procedure.

Eye movements are one of the most complex motor functions of the central nervous system (CNS). Eye movement disorders including nystagmus occur in diseases of the CNS and the vestibular system. A systematic clinical examination often allows a topodiagnostic classification of the lesion.The basics of eye movements, the role of the cerebellum, the clinical examination of the oculomotor system, and the most important forms of nystagmus and their diagnostic implications are described.A literature analysis assessing eye movements, cerebellar control of eye movements, clinical examination of eye movement, and nystagmus was performed.In disorders of eye movement, diseases of the oculomotor cranial nerves and the central nervous structures are to be distinguished from diseases of the orbit, eye muscles, and motor end plates. The former result in cranial nerve-related paralysis of extraocular muscles, disturbances of saccadic and smooth pursuit eye movements, vertical or horizontal gaze palsy, internuclear ophthalmoplegia, or impaired gaze holding. Nystagmus in combination with other disturbances of ocular movement is highly related to a lesion within the CNS. Intense nystagmus with a rotatory component that decreases during fixation usually has a peripheral vestibular cause.Clinical examination of eye movements and nystagmus enables the diagnosis of typical eye movement disorders with a strong relation to distinct lesions of the CNS or the peripheral vestibular pathway.

The diagnosis of the various peripheral and central vestibular disorders is mainly based on the patient history (time course, type of symptoms, modulating factors, and accompanying symptoms) and a systematic clinical examination of the vestibular, ocular motor, and cerebellar systems (examination for nystagmus, head impulse test, positional maneuvers, Romberg test and examination for central ocular motor signs). The two most important laboratory tests are the "video-head impulse test" and caloric irrigation. Fortunately, the diagnosis of vestibular disorders has become easier and more precise as a result of the very clinically oriented diagnostic criteria of the Bárány Society (www.jvr-web.org/ICVD.html).Die Diagnose der verschiedenen peripheren und zentralen Schwindelsyndrome basiert auf einer systematischen Anamnese und kombinierten klinischen Untersuchung der vestibulären, okulomotorischen und zerebellären Systeme. Die wichtigsten apparativen diagnostischen Verfahren sind der Video-Kopfimpulstest und die kalorische Testung. Die Diagnosestellung ist durch die neuen Diagnosekriterien der Bárány-Society vereinfacht worden (www.jvr-web.org/ICVD.html).

Dizziness and vertigo are some of the most common reasons for seeking medical help. Acute dizziness and vertigo require interdisciplinary cooperation. New diagnostic methods (the video head impulse test) and modern algorithms (HINTS: head impulse test/nystagmus [direction changing]/test-of-skew) are increasingly used in case of the acute vestibular syndrome in emergency care.In a survey on the management and participation of the ENT specialist area, the authors interviewed 168 German ENT clinics during the spring of 2017 using an online survey.Of the 168 departments, 100 departments participated in the survey. The specialties with first medical contact in cases with acute vertigo were ENT (48%), neurology (32%), and internal medicine (17%). Most of the patients were hospitalized. Patients with acute dizziness were referred most commonly to the ENT (62%) and neurology (16%) departments for further therapy, rarely, to internal medicine wards. For emergency diagnostic workup, the video head impulse test is frequently used in ENT (72%).In acute vertigo syndromes, the ENT physician has a special role and responsibility in the interdisciplinary workup, since ontological disorders are the most common cause. In any case, an ENT consultation is recommended. In German emergency departments, otorhinolaryngologists use modern diagnostic tools and algorithms such as the video head pulse test and HINTS to objectify peripheral vestibulopathy or identify central causes. Thus, this is a contribution to improving medical care.

Superior canal dehiscence syndrome (SCDS) is a relatively rare neurotological disorder that is characterized by a heterogeneous clinical picture. Recently, vestibular evoked myogenic potential (VEMP) measurementwas established for the diagnosis of SCDS. In the present study, a case series of patients with SCDS were analyzed, with a focus on VEMP.Four patients with SCDS were prospectively examined with ocular VEMP (oVEMP) and cervical VEMP (cVEMP). The clinical features and the standard audiovestibular test battery results are summarized and analyzed. The diagnostic accuracy of VEMP testing is evaluated.The increased oVEMP amplitudes had a specificity of 100% in this patient population. All patients had normal caloric function and head impulse testing. The Tullio sign was observed in two patients. Three patients had autophony. The airbone gap was not greater than 10 dB in any of the patients. Two patients had marked fremitus nystagmus. All patients had a bony dehiscence of the superior semicircular canal on computed tomography imaging.The subjective and clinical features in this case series of SCDS patients were heterogeneous. However, objective oVEMP testing had the highest diagnostic value. Furthermore, we describe a new diagnostic clinical sign: fremitus nystagmus.

The current paper reports on a patient with recurrent rotational vertigo and persistent dizziness and imbalance lasting weeks, who underwent extensive neurootological and radiological examination. Pathological findings initially included right-sided benign paroxysmal positional vertigo (BPPV), persistent horizontal spontaneous nystagmus (SPN) to the left and a pathological bedside and video head impulse test (HIT) on the left. The pathological HIT on the left and SPN to the left indicated a central genesis. Therefore, cMRI was performed and revealed a left-sided cerebral infarction in the territory of the medial branch of the posterior inferior cerebellar artery (mPICA).

This article presents an overview of the pathophysiology of nystagmus and the differential diagnostics of congenital and acquired nystagmus. In addition, the principles of conservative, surgical and pharmacotherapy treatment options are described. The pathophysiological basis of nystagmus deepens the understanding of the etiology of the individual forms of nystagmus. The therapeutic approach to calming of nystagmus aims at an extension of the foveation time, which has the most significant impact on visual acuity. In congenital nystagmus this can be carried out by optimization of the retinal image, prisms or by bilateral surgical muscle repositioning to use the phenomenon of a null or neutral zone. In acquired nystagmus the off-label use of centrally acting medications can sometimes be helpful to calm the nystagmus and the associated oscillopsia.

There are currently different groups of drugs for the pharmacotherapy of vertigo, nystagmus and cerebellar disorders: antiemetics; anti-inflammatories, antimenieres, and antimigraineous medications and antidepressants, anticonvulsants, aminopyridines as well as acetyl-DL-leucine. In acute unilateral vestibulopathy, corticosteroids improve the recovery of peripheral vestibular function, but currently there is not sufficient evidence for a general recommendation. There is insufficient evidence to support the view that 16 mg t. i. d. or 48 mg t. i. d. betahistine has an effect in Menière's disease. Therefore, higher dosages are recommended. In animal studies, it was shown that betahistine increases cochlear blood flow. In vestibular paroxysmia, oxcarbazepine was effective (one randomized controlled trial (RCT)). Aminopyridines are recommended for the treatment of downbeat nystagmus (two RCTs) and episodic ataxia type 2 (EA2, one RCT). There has been no RCT on the efficacy of beta-blockers or topiramate but one RCT on flunarizine in vestibular migraine. Based on clinical experience, a treatment analogous to that for migraine without aura can be recommended. Acetyl-DL-leucine improved cerebellar ataxia (two observational studies); it also accelerated central compensation in an animal model of acute unilateral lesion, but RCTs were negative. There are ongoing RCTs on treatment of vestibular paroxysmia with carbamazepine (VESPA), acute unilateral vestibulopathy with betahistine (BETAVEST), vestibular migraine with metoprolol (PROVEMIG), benign paroxysmal positional vertigo with vitamin D (VitD@BPPV), EA2 with 4-aminopyridine versus acetazolamide (EAT-2-TREAT), and cerebellar ataxias with acetyl-DL-leucine (ALCAT).Zur Pharmakotherapie von vestibulären Erkrankungen kommen im Wesentlichen folgende Wirkstoffgruppen zum Einsatz: Antivertiginosa, Antikonvulsiva, Antidepressiva, Antiphlogistika, Anti-Menière-wirksame Substanzen, Migräneprophylaktika, Aminopyridine (Kaliumkanalblocker) und Acetyl-DL-Leucin (eine modifizierte essenzielle Aminosäure). Die Behandlung des Symptoms Schwindel und der begleitenden vegetativen Beschwerden wie Übelkeit, Brechreiz oder Erbrechen sollte zeitlich stets begrenzt werden. Bei einem akuten einseitigen Vestibularisausfall verbessern Kortikosteroide die Erholung der peripher vestibulären Funktion, ohne ausreichende Evidenz für eine allgemeine Empfehlung.Für die Wirksamkeit von Betahistin (16 mg dreimal täglich oder 48 mg dreimal täglich) bei Morbus Menière gibt es bislang keine ausreichende Evidenz, ggf. sollten hierbei höhere Dosierungen angestrebt werden – insbesondere, da in tierexperimentellen Studien eine Verbesserung der Durchblutung des Innenohrs nachgewiesen wurde. Bei der Vestibularisparoxysmie sind Carbamazepin/Oxcarbazepin wahrscheinlich wirksam, es fehlen aber noch randomisierte kontrollierte Studien (RCTs) dazu. Bei der vestibulären Migräne gibt es bislang keine RCTs zur Wirksamkeit von Betablockern oder Topiramat, so dass hier aufgrund von klinischen Erfahrungen die Therapie in Analogie zur Migräne ohne Aura empfohlen wird.Aminopyridine werden für die Behandlung von Patienten mit Downbeat-Nystagmus (2 RCTs) und der episodischen Ataxie Typ 2 (EA2, 1 RCT) empfohlen. Die Wirksamkeit von Aminopyridinen wurde in tierexperimentellen und funktionellen Bildgebungsstudien evaluiert. Acetyl-DL-Leucin, eine modifizierte essenzielle Aminosäure, verbessert die klinischen Symptome der zerebellären Ataxie (bisher 3 Beobachtungsstudien). Nach tierexperimentellen Studien beschleunigt es auch die zentrale Kompensation vestibulärer Störungen; randomisierte klinische Studien dazu waren negativ. Derzeit werden die folgenden klinischen RCTs zu verschiedenen Erkrankungen durchgeführt: Vestibularisparoxysmie (Carbamazepin, VesPa), akute einseitige Vestibulopathie/Neuritis vestibularis (Betahistin, BETAVEST), vestibuläre Migräne (Metoprolol, PROVEMIG), BPPV (Vitamin D, VitD@BPPV), EA2 (Aminopyridin vs. Acetazolamid, EAT-2-TREAT) und zerebelläre Ataxien (Acetyl-DL-Leucin, ALCAT).

The goal of treatment for nystagmus is to reduce or to abolish the typical symptoms associated with nystagmus. These are (i) reduction of visual acuity (and amblyopia in infantile nystagmus), (ii) abnormal head posture (with possible secondary changes of cervical spine) and (iii) oscillopsia (often connected with vertigo and disorders of gait and orientation). Treatment strategies include pharmacological treatment, surgical therapy and optical devices. Choice of treatment depends on the type of nystagmus and its characteristics.The following surgical procedures were successfully used as treatment of selected symptoms: (i) unilateral recess-resect surgery of the dominant eye in infantile esotropia with latent nystagmus for the relief of abnormal head posture, (ii) Kestenbaum operation of both eyes in infantile nystagmus syndrome with excentric null zone and abnormal head posture, (iii) recess-resect surgery to produce artificial exophoria in infantile nystagmus syndrome. PHARMACOLOGICAL TREATMENT: Depending on the pathophysiology of different types of nystagmus, several drugs were effective in clinical application (off-label use): (i) gabapentin (non-selective GABAergic and anti-glutamatergic effect): up to 2400 mg/d in infantile nystagmus, acquired pendular nystagmus and oculopalatal tremor, (ii) nemantine (anti-glutamatergic effect): dosage up to 40 mg/d in infantile nystagmus, also in acquired pendular nystagmus and oculopalatal tremor, (iii) baclofen (GABA-B-receptor agonist): 3 × 5-10 mg/d in periodic alternating nystagmus and in upbeat nystagmus, (iv) 4-aminopyridine (non-selective blocker of voltage-gated potassium channels): 3 × 5 mg/d or 1-2 × 10 mg Fampridin in downbeat nystagmus and upbeat nystagmus, (v) acetazolamide (carbonic anhydrase inhibitor): in hereditary episodic ataxia type 2. OPTICAL DEVICES: (i) Contact lenses are used in infantile nystagmus in order to overcome negative effects of eye glasses in abnormal head posture, lateral gaze, and higher refractive errors, (ii) spectacle prisms are useful to induce an artificial exophoria (base-out prisms) or to shift an excentric null zone (base in direction of head posture) of infantile nystagmus with abnormal head posture, (iii) low vision aids may be necessary and should be prescribed according to magnification requirements.

PURPOSE: The optokinetic system in healthy humans is a negative-feedback system that stabilizes gaze: slow-phase eye movements (i.e., the output signal) minimize retinal slip (i.e., the error signal). A positive-feedback optokinetic system may exist due to the misrouting of optic fibers. Previous studies have shown that, in a zebrafish mutant with a high degree of the misrouting, the optokinetic response (OKR) is reversed. As a result, slow-phase eye movements amplify retinal slip, forming a positive-feedback optokinetic loop. The positive-feedback optokinetic system cannot stabilize gaze, thus leading to spontaneous eye oscillations (SEOs). Because the misrouting in human patients (e.g., with a condition of albinism or achiasmia) is partial, both positive- and negative-feedback loops co-exist. How this co-existence affects human ocular motor behavior remains unclear. METHODS: We presented a visual environment consisting of two stimuli in different parts of the visual field to healthy subjects. One mimicked positive-feedback optokinetic signals and the other preserved negative-feedback optokinetic signals. By changing the ratio and position of the visual field of these visual stimuli, various optic nerve misrouting patterns were simulated. Eye-movement responses to stationary and moving stimuli were measured and compared with computer simulations. The SEOs were correlated with the magnitude of the virtual positive-feedback optokinetic effect. RESULTS: We found a correlation among the simulated misrouting, the corresponding OKR, and the SEOs in humans. The proportion of the simulated misrouting needed to be greater than 50% to reverse the OKR and at least greater than or equal to 70% to evoke SEOs. Once the SEOs were evoked, the magnitude positively correlated to the strength of the positive-feedback OKR. CONCLUSIONS: This study provides a mechanism of how the misrouting of optic fibers in humans could lead to SEOs, offering a possible explanation for a subtype of infantile nystagmus syndrome (INS).

Nystagmus can be associated with strong discomfort due to oscillopsia, blurry vision and dizziness. Since generally no curative treatment methods exist, studies focus on potential pharmaceuticals to dampen the nystagmus. An overview is given on which forms of nystagmus can be treated with what kind of pharmacological substances and their possible mechanism of nystagmus dampening. Controlled studies found gabapentin and memantine to be effective in acquired pendular nystagmus and early-onset idiopathic nystagmus, and an efficacy of 4-aminopyridine in downbeat nystagmus.

Nystagmus causes blurred vision due to oscillopsia, as well as impaired balance. Depending on etiology, additional cerebellar and brain stem signs may occur. We present the current pharmacotherapy of the most common forms of central nystagmus: downbeat nystagmus (DBN), upbeat nystagmus (UBN), acquired pendular nystagmus (APN), and congenital nystagmus (CGN). Recommended medical therapies are aminopyridines (4-AP) for DBN and UBN, gabapentin and memantine for CGN and APN, and baclofen for periodic alternating nystagmus (PAN).

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.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.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.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.

Cochlear implantation (CI) may induce vestibular impairment soon after surgery as well as after implant activation. This impairment seems to be independent from the cause of deafness and can be considered a possible complication from the intra-operative trauma and, to minor degree, from the ongoing electric stimulation. It would also seem that vestibular damage occurs independently from the likelihood of post-operative hearing deterioration. In unilateral selected CI cases, vestibular examination can be proposed as additional pre-operative exam for selection of the ear to be implanted.This study has been planned in order to get evidence of eventual impairment of the vestibular apparatus after cochlear implantation as well as to verify whether the impairment could be related to different variables, such as cause of deafness, concomitant hearing deterioration, surgical trauma and duration of electrical stimulation.Charts from two different populations of implantees have been reviewed, 21 from a prospective, 72 from a retrospective study, respectively. All the patients were implanted with Clarion(R) devices of different generation. Vestibular testing was based on rotatory, caloric (when possible) and stabilometric measurements, which were carried out pre-operatively and at the following different times: 5 weeks after CI surgery, and 30, 60 and 90 days after CI activation. Hearing thresholds were also assessed in those patients who showed signs of vestibular impairment as well as in a group of patients without vestibular disorders (control). Patients belonging to the retrospective group were all asked to fill a questionnaire regarding their balance condition. Results. In 14.3% of the prospective study group, a grade I and II spontaneous nystagmus was evidenced pre-operatively and remained unchanged during the whole assessment period. A grade II spontaneous nystagmus was present in 3 patients (21.4%) of the same group after surgery. In the immediate post-operative period, vestibular impairment was displayed as true rotational vertigo in 21.4% and unsteadiness in 42.8% of the study group. Severe unsteadiness was present during the first 2 days after activation in 14.3% of the subjects. In 21.4% of the patients a VPPB episode occured. In the retrospective study group, 26.4% of the subjects referred pre-operative dizziness and 25 patients (34.7%) referred immediate post-operative vertigo episodes, which remained in a milder form after CI activation in 12% of them. The hearing threshold showed to deteriorate in both vestibular-impaired and control CI population without significant difference.

A prerequisite for a qualified analysis of nystagmus is the recognition of uncommon forms of this condition. In internuclear ophthalmoplegia (INO), a dissociated nystagmus in side gaze is typical. This is accompanied by limited medial excursion of the adducted eye together with a dissociated nystagmus, which is stronger in the abducting fellow eye. This motility disturbance stems from a lesion in the medial longitudinal fasciculus running in the brain stem between the sixth and the third nerve nuclei. The lesion is often due to multiple sclerosis, but can also be ischemic, traumatic, neoplastic or inflammatory (e.g. HIV infection).

Convection and conduction are the main factors involved in caloric response. Heat radiation has also been discussed as an important factor. The present work tests whether heat radiation is an essential part of the caloric response and whether caloric irritation of the semicircular canals is possible using two sources with a different near infrared (NIR) spectrum. In addition, we tested whether it is possible to induce a detectable nystagmus reaction using either NIR-radiation sources.NIR is able to penetrate bone tissue. The temperature elevation in dry and wet bones was almost immediately registered. With high optical power, specific temperature maxima could be seen by focal and selective broad spectrum and monochromatic NIR irritation of the three semicircular canals. Nystagmus could be generated after using both NIR emission sources in five probands.NIR generates temperature differences and nystagmus. By using a broad scale as well as a monochromatic NIR-emission source, it is possible to generate a nystagmus. The procedure of NIR-irritation occurs without physical contact, is painless and quiet.

A new method for the stimulation of the organ of equilibrium by means of a broad-scale and monochromatic near infrared emission was developed. This method should be examined within the framework of a pilot study, evaluated and its clinical possible applications examined.Healthy probands (n = 15), patients with a radical cave of the ear (n = 5), patients with a defect of the tympanic membrane (n = 5) and spontaneous nystagmus (n = 5) were examined. In healthy probands an irritation with broad-scale as well as monochromatic near infrared (NIR) was performed and compared with a water irrigation (44 degrees, 50 ml in 30 seconds). The subjective, local feelings during the application and the appearance of giddiness according to irritation were recorded and the nystagmus was registered by means of videonystagmography. In patients with radical cave of the ear and tympanic membrane defects, a broad-scale NIR-irritation before a comparative irritation with warm air (44 degrees) was performed exclusively.In all healthy probands, a nystagmus reaction could be seen with broad-scale and monochromatic NIR. Compared to the hot water irritation slow phase velocity (SPV) was decreased however registrable by means of Frenzel glasses and electronystagmography during the culmination stage. In patients with radical cave (n = 4) and tympanic membrane defects (n = 3) showing paradoxical nystagmus reaction during hot air irritation, a nystagmus to the site of stimulation resulted by means of light calorisation. In patients with a spontaneous nystagmus an attenuation (n = 1) or inversion (n = 2) could be achieved by NIR-radiation.The method of the NIR-radiation is suitable in clinical practice for the caloric test proofing warm reaction. Vaporization cold does not occur. The application of heat charm is better proportionable and steerable than during air irritation. The procedure is sterile, noiseless and non-contact. Difficulties in interpretation of results of vestibular tests because of evaporation coldness do not occur.

A perilymph fistula is a possible cause for sudden unilateral sensory deafness. In this retrospective study the data of 73 patients with unilateral sudden deafness were analyzed. All of them underwent an exploratory tympanotomy during which both windows were packed with soft tissue. Postoperatively all patients received rheological therapy with pentoxifyllin and steroids. The following possible prognostic indicators were analyzed: age, sex, tinnitus, vertigo, vomiting, spontaneous nystagmus, positive fistula test, time between onset of symptoms and therapy, intraoperative proof of a perilymph fistula, and signs of barotrauma in the patient's history. A significant postoperative recovery of the hearing loss (20%) was found in 29 patients (39.7%) (group 1), and 44 patients (60.3%) showed only an increase of20% (group 2). The statistical analyses showed the following significant difference: The symptoms vertigo (p=0.002) and spontaneous nystagmus (p=0.014) occurred more frequently in group 2 (patients with a poor hearing recovery) than in group 1. Patients with a barotrauma,however, had an overproportionally good outcome (50-100% hearing recovery). A perilymph fistula was seen intraoperatively equally often in both groups. In summary, the symptoms vertigo and spontaneous nystagmus are indicators of complex damage in cases of sudden deafness and are associated with a worse prognosis concerning hearing recovery. Exploratory tympanotomy in combination with drug treatment is a reasonable therapy as an ultima ratio in every case of unilateral sudden deafness.

Vestibuloocular and vestibulospinal reactions following the bilateral loss of vestibular function are designated as Bechterew's phenomenon. In vestibular physiology, under experimental conditions, this phenomenon has played an important role for understanding the mechanisms underlying vestibular compensation. However, clinical reports about this phenomenon in humans are extremely rare.Bechterew's phenomen was observed throughout every stage of its development in a patient with consecutive bilateral loss of vestibular function. The disorder was documented by electronystagmography and posturography.Bechterew's phenomenon depends on different states of vestibular function developing in a certain succession, whereby the varying relations between failure and compensation are decisive. The phenomen very impressively demonstrates the resilience of the central nervous system in adapting to varying peripheral functional states. From a clinical standpoint, knowledge of these relationships is important for understanding vestibular compensation.

The recommendations of the German Society of Ophthalmology (DOG) concerning the examination of candidates or holders of a driving licence allow a maximum time interval of 1 s for identifying a single Landolt-C for normal individuals as well as for patients with nystagmus. The aim of this study was to determine whether visual acuity decreases with shortening of the exposure time.We measured the visual acuity of 18 patients with manifest nystagmus and 26 normal individuals with single Landolt-C at exposure times of 10 s, 1 s, 0.25 s and 0.1 s.Visual acuity dropped significantly at exposure times of 1 s in the group of patients with nystagmus (P = 0.01). In normal individuals, visual acuity decreased significantly only at exposure times below 1 s.Determining visual acuity according to the recommendations of the DOG shows a significant drop of visual acuity in nystagmus patients, but not in normal individuals. Applying the maximum time limit of 1 s exposure time to these patients will ensure that they will be able to identify traffic signs quickly and orient themselves safely.

Two brothers with slowly progressive weakness and congenital nystagmus are presented. DNA analysis confirmed X-linked recessive bulbospinal muscular atrophy (XBSMA, Kennedy's disease) by demonstration of increased size of a CAG-triplet repeat on the androgen receptor gene on the X-chromosome. XBSMA is characterized by almost symmetrical muscular atrophy, weakness and fasciculations predominantly of bulbar, facial and proximal muscles of the extremities, with onset in the third to fifth decade. Tendon reflexes are depressed and pyramidal signs are absent. Sensory symptoms are clinically rare, but sensory nerve action potentials are frequently abnormal. Additional symptoms are important for differential diagnosis, and include postural tremor, gynecomastia, diabetes mellitus, testicular atrophy and impotence. Differentiation of this hereditary disorder from treatable conditions such as multifocal motor neuropathy or amyotrophic lateral sclerosis is essential. Though life expectancy is normal, patients become disabled in the course of the disease and need supportive care. Periodic testing for diabetes is recommended, and genetic counseling should be provided for patients and their relatives.

By law, applicants for driver's licenses not only have to have sufficient vision, but also have to use this sight reliably. The nystagmus patient takes advantage of ocularly induced head turns and other forms of compensation. In the approved test procedures he is deprived of such compensations.The eye movements of a nystagmus patient were recorded oculographically. He was allowed to use compensatory mechanisms of body posture and movement for stabilization of vision.The nystagmus patient can achieve better visual performance when he is allowed to utilize complex segmental body movements for stabilization of vision.It is proposed that test procedures for visual performance in traffic be altered as follows: nystagmus and abnormal head postures are admittable if sufficient binocular vision is achieved. The test may use illustrations of traffic situations containing relevant details such as traffic signs. These are to be understood by the test person on triplicate presentation.

An 11-year-old girl presented because of reduced visual acuity while color vision was almost normal. Besides a general ophthalmological examination, special psychophysical tests, such as perimetry, color vision tests using pseudoisochromatic plates, arrangement tests, the Nagel anomaloscope and spectral sensitivity measurement, and electrophysiological tests (electroretinogram and electrooculogram) were conducted.The tests yielded the following: congenital nystagm, normal results at ophthalmoscopy, best visual acuity of 0.1 monocular and 0.2 binocular. Perimetry revealed a relatively central scotoma. All color vision tests showed only mild dysfunction of the blue-sensitive cones. Findings at photopic electroretinogram were almost completely lacking. There was no sign of progression in the last 6 years.Differential diagnosis includes all diseases associated with congenital nystagm, such as aniridia, diseases of the optic nerve, albinism and all forms of hereditary cone dysfunction, cone dystrophies and complete and incomplete congenital stationary monochromatism. In the present case the findings are most congruent with oligocone trichromasy.

Benign paroxysmal vertigo and nystagmus are induced not only by the posterior but also by the horizontal semicircular canal. Benign positional nystagmus of the horizontal canal is more often observed than was previously thought. In 10 patients we analyzed the characteristics and the variability of nystagmus which accompanies positional vertigo of the horizontal canal. There are two forms of nystagmus: primary-geotropic, most often paroxysmal nystagmus (7 patients), and primary-apogeotropic, non-paroxysmal nystagmus (3 patients). Interestingly, in 2 patients with the primary-apogeotropic form the nystagmus converted during the examination into the primary-geotropic form. The reverse was not observed. We discuss the possible pathophysiological mechanisms which could be relevant for provoking manoeuvres.

Visually impaired individuals who are unable to obtain a driving licence may use a bicycle and feel fit for traffic as part of this "bio-physical model".Five nystagmic amblyopes who claimed to ride a bicycle were tested in respect to visual acuity, peripheral vision and oculomotor functions. In three of these cases visual acuity amounted to 0.3, in one to 0.6, in another one only to 1/35. Eye movements were recorded by electro-oculography. The following qualities of gaze were determined: Fixation-saccadic eye movements-pursuit eye movements-behaviour in light and dark-vestibulo-optokinetic movements-eye positioning in resting states and influence of mood.In four of the cases oculomotor regularities were found. These were explained to the patients. One of the cases was affected with a form of chaotic nystagmus.Bicycling demands on both the vestibular and the visual system. Deficiencies relevant to behaviour in traffic and the possibilities to compensate for these may be estimated based on a oculographic evaluation. This should therefore be used to advise bicyclists with a visual impairment.