No abstract available.
Infarction* ; Nystagmus, Physiologic*

BACKGROUND AND OBJECTIVES: Benign paroxysmal positional vertigo (BPPV) of horizontal canal shows reversible direction changing positional nystagmus and diverse clinical courses because of the frequent clinical presentation of cupulolithiasis. The aim of this study is to find out the early effect of particle repositioning maneuver (PRM) including the barbecue and the modified Semont in single treatment session for the apogeotropic horizontal canal BPPV. SUBJECTS AND METHOD: Thirty-three episodic vertigo patients with direction-changing apogeotropic horizontal nystagmus were enrolled in this study. The patients were initially treated with barbecue rotation and the second PRM was applied 15 minutes after the first PRM. Barbecue rotation was applied when the positional nystagmus was changed its direction to that of geotropic. The modified Semont maneuver or barbecue rotation was randomly applied when nystagmus was not changed. Patients were followed-up 2 or 3 days after the initial visit and the nystagmus was rechecked to determine the single session treatment result. RESULTS: The combination of PRMs in a single treatment session was effective in 23 out of 33 (69.7%) patients. An initial barbecue rotation was effective in 17 patients (51.5%); geotropic nystagmus was obtained in 12, and no nystagmus in 5. Eleven out of 16 (68.8%) patients with persistent apogeotropic nystagmus after initial treatment were successfully treated with the second PRM. There was no statistical difference between the second PRMs of the modified Semont maneuver and barbecue rotation (p=1.000). CONCLUSION: The combination of PRMs including barbecue rotation and the modified Semont maneuver in a single treatment session showed a comparable success rate as the previously reported studies.
Humans ; Nystagmus, Pathologic ; Nystagmus, Physiologic ; Vertigo

BACKGROUND AND OBJECTIVES : Ageotrophic nystagmus in the horizontal canal BPPV has been explained as a result of cupulolithiasis theory, and has been reported to have the less therapeutic response to conservative rehabilitations than the other type BPPV . Though methods to detach the debris with vibrator have been introduced, the effect has been questioned and it's not physiologic. MATERIALS AND METHOD : We introduce a new head shaking-forced prolonged position method as a more convenient method, and report typical 2 cases of ageotrophic horizontal canal BPPV managed with it and analyzed results of 25 cases all told. RESULTS AND CONCLUSION : The average number of rehabilitation was less than two, and loss of direction changing positional nystagmus could be observed immediately after rehabilitation.
Head ; Nystagmus, Physiologic ; Rehabilitation ; Vertigo*

BACKGROUND AND OBJECTIVES: In caloric test, the CP (canal paresis) value was derived from Jongkees formula. The input parameters of the formula were initially nystagmus duration (seconds), which were replaced later with more stable parameters : slow component velocity (SCV, deg/sec). The nystagmus duration cannot be negative value, but SCV can be, especially in acute vestibular loss with excessive spontaneous nystagmus (SN) which is not overcome by caloric nystagmus. This study aims to investigate the occurrence of negative SCV, to check proper processing of negative SCV values in nystagmography software, and to consider the mathematical significance of CP and negative SCV values. MATERIALS AND METHOD: Tests with negative SCV values were examined in 690 alternate binaural bithermal caloric tests (open loop system). RESULTS: Nine percents (62 of 690 tests) showed negative SCV values. The reported CP was erroneously calculated from debased zero SCV values instead of negative SCV values. The underestimated CP (mean 52.1%, SD 21.8%) can be corrected (mean 80.9%, SD 21.8%) by recalculations with negative SCV values. CONCLUSION: To produce correct CP values in caloric tests, negative values should be properly processed about the SCV value of caloric nystagmus with opposite direction of physiologic response. The mathematical significance of CP was horizontal coordinate of intersection point of the warm line (LW-RW) and cold line (LC-RC) in butterfly pattern calorigram. Detailed description is presented in figures.
Butterflies ; Caloric Tests ; Nystagmus, Physiologic

The authors report a 64-year-old man who developed persistent direction fixed nystagmus after a canalith repositioning maneuver for horizontal canal benign paroxysmal positional vertigo (HC-BPPV). The patient was initially diagnosed with right HC-BPPV given that the Dix-Hallpike test showed geotropic horizontal nystagmus that was more pronounced on the right side, although the roll test did not show any positional nystagmus. The patient was treated with a canalith repositioning maneuver (Lempert maneuver). The next day, the patient experienced a different character of dizziness, and left-beating spontaneous nystagmus regardless of head position was observed. After a forced prolonged left decubitus and frequent head shaking, his symptoms and nystagmus resolved. This condition, referred to as canalith jam, can be a complication after the repositioning maneuver in patients with BPPV. Atypical positional tests suggest that abnormal canal anatomy could be the underlying cause of canalith jam.
Dizziness ; Head ; Humans ; Middle Aged ; Nystagmus, Pathologic ; Nystagmus, Physiologic ; Vertigo

Paroxysmal positional nystagmus is a common finding in patients with vertigo and can occur in typical and atypical forms. Atypical forms of paroxismal positional nystagmus are thought to represent conditions which are in fact not "benign". This patient was diagnosed as right posterior semicircular canal BPPV at first. After modified Epley maneuver, the type of nystagmus was changed to atypical forms. After left cupulolith reposition maneuver (CRmM), the nystagmus and dizziness were disappeared finally.
Dizziness ; Humans ; Nystagmus, Physiologic ; Semicircular Canals ; Vertigo*

In unanesthetized rabbits, alcohol, glyserin, or heavy water was injected intravenously and nystagmic reaction elicited by passive alteration of body position was recorded by means of nystagmography, and the specific direction of the nystagmus was also observed. The following results were obtained 1. After Injection of alcohol (2.5~3.5ml/kg), right sloe down or lelf side down position elicited nystagmus in both eyes (FAN I) Right sloe down position elicited supero-dorsal nystagmus in the ipsilateral eye anti Infero-central nystagmus In the contralateral eye Left side down position produced nystagmus towards reversed directions 2. Returning to neutral position from one sloe down also elicited nystagmus towards the same direction. 3 From 5~6 hours after Injection of alcohol, the direction of the positional nystagmus was reversed, manifesting phase II of the PAN (PANII) 4. Injection of glycerin (2.0~3.0ml/kg) or heavy water (2.0~25ml/kg) also elicited positional nystagmus. The direction of the nystagmus was the same as and opposite to that Induced by alcohol Injection
Deuterium Oxide* ; Glycerol* ; Nystagmus, Physiologic* ; Rabbits

Bowing nystagmus, lying down nystagmus, null pointand comparing the slow phase velocity during right and left head roll test may be used to distinguish the side of lesion in lateral canal benign paroxysmal positional vertigo (BPPV). Nonetheless, it is sometimes difficult to distinguish the side of lesion. In particular, when multiple canal BPPV such as lateral and posterior canal BPPV is suspected, the problemis even more complicated. From this reason, usually the side of lesion is first identified for the posterior canal, and the lateral canal BPPV is presumed to be present on the identical side. But is this approachalways correct and justifiable? As there are reports on bilateral posterior canal BPPV and bilateral lateral canal BPPV, there should also be bilateral posterior and lateral canal BPPV cases. We report two cases of bilateral posterior and lateralcanal BPPV, and discuss the grounds for diagnosing these cases as bilateral. The first case is a mixed left posterior canalolithiasis plus right lateral canalolithiasis and the second case is a mixed right posterior canalolithiasis plus left lateral cupulolitiasis. In such cases, mixed nystagmus can make it difficult to directly compare the slow phase velocity during the right and left head roll test. New methods are necessary to distinguish the side of the lesion for the lateral canal. We introduce the concept of AHC (attenuated horizontal component) which seems to be important in deciding the side of lesion in multiple canal BPPV. We also introduce head center nystagmus (HCN) to aid the decision on the side of lesion.
Deception ; Head ; Nystagmus, Physiologic ; Semicircular Canals ; Vertigo

Direction changing positional nystagmus (DCPN) is defined as a nystagmus that changes its direction with different head and body positions. In the past, it was usually thought that DCPN was the sign of central vestibular system lesion. But recently, there have been some reports that DCPN definitely does not localize the site of lesion in the central vestibular pathway, and that it more often indicates a peripheral vestibular site. However, congenital vestibular dys- or hypoplasia was not reported as a cause of DCPN. Recently, we experienced a 17-year-old patient who had a vestibular dys- or hypoplasia and showed a transient geotrophic DCPN with a normal cochlea. We report that congenital vestibular dys- or hypoplasia can be one of the causes of DCPN and present its possible mechanism.
Adolescent ; Cochlea ; Head ; Humans ; Nystagmus, Physiologic*

OBJECTIVE: Patients with benign paroxysmal positional vertigo (BPPV) visit clinics with typical position evoked vertigo. However, typical nystagmus are concealed according to many factors We evaluated the demographic, clinical and nystagmographic features of patients, who visited clinics with typical BPPV symptoms but did not have positional test evoked nystagmus. METHODS: Among 306 patients with history of positional vertigo, we excluded 252 patients who had positional test evoked nystagmus on video Frenzel glass in clinics, and analyzed 54 patients who did not have positional test evoked nystagmus. We divided 54 patients into two groups; patients without subjective vertigo in positional test and patients with subjective vertigo in positional test. We analyzed the serial nystagmographic findings, causes, duration of disease, previous history of medical or rehabilitation treatments, coexisting vestbular disorders, recovery time and recurrence. RESULTS: Etiology, history of previous treatment, coexisting vestibular disorders and recurrence did not differ statistically in both groups. However, the nystagmographic features were significantly different in both groups. CONCLUSION: When patient has positional test evoked vertigo, repeated positional maneuver seemed to increase the expression of positional nystagmus.
Glass ; Humans ; Nystagmus, Physiologic ; Recurrence ; Rehabilitation ; Vertigo