Further exploration of the classification and clinical value of head-shaking nystagmus / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the classification of head shaking nystagmus（HSN） and its clinical value in vestibular peripheral diseases. Methods:Clinical data of 198 patients with peripheral vestibular disorders presenting with HSN were retrospectively analyzed. Video Nystagmograph（VNG） was applied to detect spontaneous nystagmus（SN）, HSN, and Caloric Test（CT）. The intensity and direction of SN and HSN as well as the unilateral weakness（UW） and direction preponderance（DP） values in caloric test was analyzed in patients. Results:Among the 198 patients with vestibular peripheral disease, there were 105 males and 93 females, with an average age of（49.1±14.4） years （range: 14-87 years）. One hundred and thirty seven patients were diagnosed as Vestibular Neuritis（VN）, 12 as Meniere's Disease（MD）, 41 as sudden deafness（SD） and 8 as Hunt's syndrome accompanied by vertigo. Among them, there were 116 patients in the acute phase, including 68 cases（58.6%） with decreased HSN, 4 cases（3.4%） with increased HSN, 5 cases（4.3%） with biphasic HSN, 38 cases（32.8%） with unchanged HSN, and 1 case（0.9%） with perverted HSN. There were 82 cases in the non-acute phase, 51 cases（62.2%） with decreased HSN, 3 cases（3.6%） with increased HSN, 9 cases（11.0%） with biphasic HSN, and 19 cases（23.2%） with unchanged HSN. In biphasic HSN, the intensity of phase I nystagmus was usually greater than that of phase II, and the difference was statistically significant（P<0.01）. There was no correlation between HSN type and course of disease or DP value. The intensity of HSN was negatively correlated with the course of disease（r=-0.320, P<0.001） and positively correlated with DP value（r=0.364, P<0.001）, respectively. The intensity of unchanged nystagmus and spontaneous nystagmus were（8.0±5.7） °/s and（8.5±6.4）°/s, respectively. There was no statistically significant difference in the intensity of nystagmus before and after shaking the head. Conclusion:HSN can be classified into five types and could be regarded as a potential SN within a specific frequency range （mid-frequency）. Similarly, SN could also be considered as a common sign of unilateral vestibular impairment at different frequencies. HSN intensity can reflect the dynamic process of vestibular compensation, and is valuable for assessing the frequency of damage in peripheral vestibular diseases and monitoring the progress of vestibular rehabilitation.

Abnormal Oculomotor Functions in Amyotrophic Lateral Sclerosis

BACKGROUND AND PURPOSE: Although traditionally regarded as spared, a range of oculomotor dysfunction has been recognized in amyotrophic lateral sclerosis (ALS) patients. ALS is nowadays considered as a neurodegenerative disorder of a third compartment comprising widespread areas of extra-motor brain including cerebellum. Our objective was to perform an observational study to examine for ocular motor dysfunction in patients with ALS and for any differences between bulbar-onset and spinal-onset patients. METHODS: Thirty two ALS patients (bulbar onset: 10, spinal onset: 22) underwent the standardized systemic evaluations using video-oculography. RESULTS: Oculomotor dysfunctions such as square wave jerks, saccadic dysmetria, abnormal cogwheeling smooth pursuits and head shaking and positional nystagmus of central origin have been observed in the ALS patients at a relatively early stage. Abnormal smooth pursuits and saccadic dysmetria were increased in the bulbar-onset compared to the spinal-onset (p < 0.05). CONCLUSIONS: These oculomotor abnormalities may be a marker of neuro-degeneration beyond motor neurons in ALS, especially in bulbar-onset disease. Future longitudinal studies of eye movement abnormalities have provided insights into the distribution and nature of the disease process.

Pseudo-Spontaneous Nystagmus and Head-Shaking Nystagmus in Horizontal Canal Benign Paroxysmal Positional Vertigo / 대한평형의학회지

OBJECTIVES: The purpose of this study was to examine the clinical manifestations and significance of pseudo-spontaneous nystagmus (PSN) and head-shaking nystagmus (HSN) in horizontal canal benign paroxysmal positional vertigo (HC-BPPV). METHODS: Two hundred fifty-two patients diagnosed as HC-BPPV were reviewed retrospectively. After excluding 55 patients with ipsilateral vestibular diseases, multiple canal BPPV, or those who were lost to follow-up, we analyzed the direction of PSN and HSN in patients with HC-BPPV. We also compared the clinical characteristics and treatment outcome between PSN-positive and PSN-negative groups. RESULTS: Our study included 197 patients composed of 80 patients with geotropic HC-BPPV and 117 patients with apogeotropic HC-BPPV. PSN was observed in 13.7% patients and HSN was observed in 45.2%. The incidence of HSN was higher in apogeotropic HC-BPPV, while the proportion of PSN was not statistically significant between the two subtypes. There was no directional preponderance in geotropic HC-BPPV, while ipsilesional PSN and contralesional HSN showed higher incidence in apogeotropic HC-BPPV. The dizziness handicap inventory score in the PSN-positive group was higher than that in the PSN-negative group (p<0.001), and the duration of symptom onset in the PSN-positive group was shorter than that in the PSN-negative group (p=0.047). However, there was no significant difference in the treatment outcome between the two groups. CONCLUSIONS: The incidence of HSN was higher than that of PSN in patients with apogeotropic HC-BPPV. Patients with HC-BPPV showing PSN demonstrated more severe initial symptoms and visited the hospital in a shorter period of time after the onset of symptoms.

A clinical study into the vestibular function and therapy of patients with chronic positional symptoms after acute vestibular syndrome / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the status of the vestibular function of the patients with chronic positional symptoms after peripheral acute vestibular syndrome (AVS) and the curative effect of the vestibular rehabilitation therapy (VRT). Method:Using caloric test (CT), head shaking nystagmus test (HST), cervical vestibular evoked myogenic potentials as well as ocular vestibular evoked myogenic potentials to estimate the function of semicircular canal and otolith organs. The patients with normal VEMPs are divided as Group A. Otherwise are as Group B. Both groups are treated with VRT. The curative effect is estimated by vestibular symptom index (VSI) and Berg balance scale (BBS). Result:Thirty-three of 37 patients (86.5%) had an abnormal result of CT and HST, with 23 of these patients (65.7%) had an abnormal of both test. Twenty-two patients (59.5%) were in Group A and 15 (40.5%) in Group B. Before the therapy, Group B had a higher score of the balance and dizziness symptoms of VSI (P<0.05), and Group A had a higher score of the BBS (P<0.05). After the therapy, the VSI scores of both groups dropped and scores of the BBS raised. Conclusion:Patients with chronic positional symptoms after peripheral AVS have dynamic vestibular lesions to different extents. Those with otolith organs lesions tend to have a worse function of balance. Nevertheless, patients have a better off after VRT.

Lateral Medullary Infarction with Ipsilesional Gaze-Evoked and Head-Shaking Nystagmus / 대한평형의학회지

For differential diagnosis between vestibular neuritis and lateral medullary infarction with similar clinical features, bedside examination of nystagmus is important. We report a 45-year-old male who presented with acute vertigo for two days. He showed spontaneous right-beating nystagmus. However, left-beating nystagmus was evoked during bilateral horizontal gaze and by horizontal head oscillation. Brain MRI revealed an acute infarction in the left lateral medulla.

Downbeat, Gaze-evoked and Perverted Head-shaking Nystagmus Associated with Dapsone Toxicity / 대한평형의학회지

Dapsone is an agent commonly used to treat leprosy and its most common adverse effect is a hemolytic anemia. We present a patient who showed transient downbeat, bilateral horizontal gaze-evoked nystagmus (GEN), and perverted head-shaking nystagmus after taking a large dose of dapsone. These oculomotor abnormalities are assumed to be a reversible vestibulocerebellar dysfunction caused by over-dose of dapsone.

Tilt Suppression of the Post-rotatory Nystagmus in Cerebellar Nodular Lesions

BACKGROUND AND OBJECTIVES: Head tilt at the end of step rotation about a vertical axis decreases the time constant (TC) of the post-rotatory nystagmus, which is known as tilt-suppression of the vestibulo-ocular reflex (VOR). Tilt suppression of the VOR is mediated by the cerebellar nodulus and ventral uvula and is eliminated after surgical ablation of those structures. However, studies on the tilt suppression of the VOR have been sparse in humans with cerebellar lesions. MATERIALS AND METHODS:Five patients with circumscribed cerebellar lesions involving the nodulusor ventral uvula underwent recording of spontaneous and positional nystagmus, and the VOR. To evaluate tilt suppression of the VOR, the participants pitched their head forward at the end of step rotation about a vertical axis both in the clockwise and counter-clockwise directions. RESULTS: The VOR gain was increased in a patient with infarction in the territory of the medial posterior inferior cerebellar artery while the gain of visually enhanced VOR was normal in all the patients. The time constants of per- and post-rotatory nystagmus was increased in a patient with increased VOR gain and the tilt suppression of the post-rotatory nystagmus was impaired in two patients, either uni- or bilaterally. Spontaneous downbeat and central positional nystagmus were frequently accompanied. CONCLUSIONS: Nodular lesion may impair tilt suppression of the VOR. Measurement of tilt suppressive effect of the VOR may provide a valuable tool for evaluating the nodular dysfunction.

Downbeat, Positional, and Perverted Head-Shaking Nystagmus Associated with Lamotrigine Toxicity

Lamotrigine is an effective antiepileptic drug with few adverse effects. Nystagmus is one of the commonly observable signs of lamotrigine overdose, which may result from central nervous system involvement. However, the physiologic basis of lamotrigine-induced nystagmus is not fully understood. Here we report a patient who presented with lamotrigine-associated nystagmus that was probably related to cerebellar dysfunction.

Perverted Head Shaking Nystagmus due to Cerebellar Lesions: Possible Mechanisms

BACKGROUND AND OBJECTIVES: Perverted head-shaking nystagmus (HSN) refers to nystagmus that develops in the plane other than that being stimulated by head oscillation, i.e., downbeat or upbeat HSN after head oscillation in the yaw plane. However, the mechanism of perverted HSN is unknown. To elucidate the mechanism of perverted HSN by measuring tilt suppression of the vestibule-ocular reflex (VOR). MATERIALS AND METHOD: Twenty two consecutive patients with perverted HSN from cerebellar lesions (13 circumscribed and 9 diffuse) and 50 normal volunteers underwent recording of spontaneous, head-shaking and positional nystagmus, smooth pursuit, saccades, and the VOR. Tilt suppression method was to pitch patients' head forward further at the end of the step rotation stimuli. RESULTS: HSN was pure downbeat in nine and mixed horizontal-downbeat in 13 patients. The mean VOR time constants did not differ between normal controls and patients. However, tilt suppression of the post-rotatory nystagmus was impaired in the patients (p<0.01). Downbeating (n=12) and central positional nystagmus (n=12) were frequently accompanied findings. CONCLUSION: Uvulonodular dysfunction was frequently observed in patients with perverted HSN from cerebellar lesions. Uvulonodulus may be involved in the spatial organization of the velocity storage mechanism and uvulonodular dysfunction may be responsible for developing perverted HSN in cerebellar lesions.

Perverted Head Shaking Nystagmus due to Cerebellar Lesions: Possible Mechanisms

BACKGROUND AND OBJECTIVES: Perverted head-shaking nystagmus (HSN) refers to nystagmus that develops in the plane other than that being stimulated by head oscillation, i.e., downbeat or upbeat HSN after head oscillation in the yaw plane. However, the mechanism of perverted HSN is unknown. To elucidate the mechanism of perverted HSN by measuring tilt suppression of the vestibule-ocular reflex (VOR). MATERIALS AND METHOD: Twenty two consecutive patients with perverted HSN from cerebellar lesions (13 circumscribed and 9 diffuse) and 50 normal volunteers underwent recording of spontaneous, head-shaking and positional nystagmus, smooth pursuit, saccades, and the VOR. Tilt suppression method was to pitch patients' head forward further at the end of the step rotation stimuli. RESULTS: HSN was pure downbeat in nine and mixed horizontal-downbeat in 13 patients. The mean VOR time constants did not differ between normal controls and patients. However, tilt suppression of the post-rotatory nystagmus was impaired in the patients (p<0.01). Downbeating (n=12) and central positional nystagmus (n=12) were frequently accompanied findings. CONCLUSION: Uvulonodular dysfunction was frequently observed in patients with perverted HSN from cerebellar lesions. Uvulonodulus may be involved in the spatial organization of the velocity storage mechanism and uvulonodular dysfunction may be responsible for developing perverted HSN in cerebellar lesions.

Perverted Head Shaking Nystagmus in a Patient with Cerebellar Infarction

Perverted head shaking nystagmus (pHSN) refers to a phenomenon that the head shaking nystagmus occurs in a different plane than the vestibular stimulus. pHSN signifies central vestibular dysfunction. The authors describe a patient who showed an isolated downbeat head shaking nystagmus from a focal cerebellar infarction in the territory of the medial posterior inferior cerebellar artery. Head shaking maneuver should be applied to all patients with isolated vertigo from a presumed vascular origin.

The Significance of Head-Shaking Nystagmus in the Vestibular Evaluation of the Chronic Dizzy Patient

OBJECTIVES : Nystagmus after rapid head-shaking (head-shake nystagmus) is transient horizontal nystagmus which is observed after passive horizontal headshake by yaw axis. It has been used for the evaluation of the remnant vestibular function. This study compared one patient group complaining of chronic vertigo with another normal group with no symptom. We tried to confirm the efficacy as a tool for the evaluation of the vestibular function in the old who had less knowledge of diasease itself, by searching the occurrence rate of head-shake nystagmus by age. MATERIALS AND METHODS : Of dizzy patients under Vertigo Index III, 19 patients with normal ENG and 20 patients showing only the decrease of the gain on the rotatory test were selected, and head-shake nystagmus was evaluated. Normal control (n=12) were all the heathy patients without any history of the otologic illness after consideration of their age. Eye movement was recorded with ENG testing and Frenzel glasses for 1minute in the dark room after vigorous head shaking at a frequency of 2Hz. Presence or absence of the head-shake nystagmus was judged by two otolaryngologist. RESULTS : Only 41% (16/39) of the dizzy patients showed headshake nystagmus. On the other hand, 8% (1/12) of normal control group revealed headshake nystagmus(p < 0.03). 50% (10/20) of the patient group showing the decrease of the gain, and 31% (6/19) of the another group with normal vestibular function revealed headshake nystagmus. When the detection rate of the nystagmus is compared according to the testing methods, it is 33% (17/51) by ENG testing, 12% (6/51) by Franzel glass test. Incidence rate of the headshake nystagmus by age is 25% (5/20) in the dizzy patient group under 50 years old, 58% (11/19) in the group over 50 years old(p < 0.03). CONCLUSION : Head-shake nystagmus showed some difference according to the vestibular compensatory periods, but Its sensitivity was 41% and it is thought to be used convenient just in the old. However, attention should be paid to observe the nystagmus in case of using the Frenzel glasses.