Comparing survival and mortality in patients with late-onset and young-onset vascular dementia.

OBJECTIVES: Vascular dementia (VD) is one of the more common types of dementia. Much is known about VD in older adults in terms of survival and associated risk factors, but comparatively less is known about VD in a younger population. This study aimed to investigate survival in people with young-onset VD (YO-VD) compared to those with late-onset VD (LO-VD) and to investigate predictors of mortality. DESIGN: Retrospective file review from 1992 to 2014. SETTING: The inpatient unit of a tertiary neuropsychiatry service in Victoria, Australia. PARTICIPANTS: Inpatients with a diagnosis of VD. MEASUREMENTS AND METHODS: Mortality information was obtained from the Australian Institute of Health and Welfare. Clinical variables included age of onset, sex, vascular risk factors, structural neuroimaging, and Hachinksi scores. Statistical analyses used were Kaplan-Meier curves for median survival and Cox regression for predictors of mortality. RESULTS: Eighty-four participants were included with few clinical differences between the LO-VD and YO-VD groups. Sixty-eight (81%) had died. Median survival was 9.9 years (95% confidence interval 7.9, 11.7), with those with LO-VD having significantly shorter survival compared to those with YO-VD (6.1 years and 12.8 years, respectively) and proportionally more with LO-VD had died (94.6%) compared to those with YO-VD (67.5%), χ2(1) = 9.16, p = 0.002. The only significant predictor of mortality was increasing age (p = 0.001). CONCLUSION: While there were few clinical differences, and older age was the only factor associated with survival, further research into the effects of managing cardiovascular risk factors and their impact on survival are recommended.

Correction to: Optimized THP-1 differentiation is required for the detection of responses to weak stimuli.

After the publication of our article [1] we were made aware that in Fig. 2D the images for PMA 2.5 ng/ml and PMA 25 ng/ml are identical.

Regional assessment of trace element concentrations in arrow squids (Nototodarus gouldi, N. sloanii) from New Zealand waters: Bioaccessibility and impact on food web and human consumers.

The New Zealand arrow squids, Nototodarus gouldi and N. sloanii, play an important role in the marine food web, and are both economically important fishery species. This study compares trace element concentrations (As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mn, Pb, U, and Zn) in these animals from different fishing locations within New Zealand's Exclusive Economic Zone (Auckland Islands, Chatham Rise, Dunedin, Golden Bay, Taranaki, and West Coast of the South Island). Muscular mantle (the tissue usually consumed by humans) and digestive gland tissue (the primary organ for trace element accumulation) concentrations were compared among regions, revealing size, species, and sampling location effects. Overall, N. gouldi had higher concentrations of As and Zn. The Taranaki region had the highest concentrations for Cd, Co, Cu, and Zn in both tissues analysed. To assess the bioaccessibility of these trace elements to humans, an in-vitro digestion simulation experiment was conducted, revealing bioavailable concentrations overall below the maximum levels presently considered tolerable for human consumption. However, the in-vitro digestion had no observable effect upon Cd concentrations in arrow squid mantle tissue (implying that the measured concentrations are bioaccessible to humans), and revealed that Cd had the highest potential impact on marine food webs and human health. Digestive gland concentrations in particular indicate that arrow squids can be considered important vectors for trace element transfer to top predators (mean concentration for Cd: 123 ± 148 µg g-1 dw), with region-specific differences.

An Optimal Questionnaire Representing Slow Gait Speed(<1m/s) in Community-dwelling Older Adults: The Korean Frailty and Aging Cohort Study (KFACS).

OBJECTIVES: This study was conducted to find an optimal questionnaire to evaluate the slow gait speed seen in community dwelling elderly. DESIGN: Four questions asking about difficulty in walking were compared against the measured usual gait speed. The questions were: 1) Is it difficult to walk 100 m without help? 2) Is it difficult to walk 300 m without help? 3) Is it difficult to walk around one lap of a 400-meter track without help? 4) Can you cross a crosswalk before the green on the crosswalk light turns red? PARTICIPANTS: The subjects were 1479 older adults aged 70 to 84 years who had responded to the four questions and completed gait speed measuring in the first baseline year (2016) of the Korean Frailty and Aging Cohort Study. RESULTS: Of the four questions, "Is it difficult to walk around one lap of track (400 m) without help?" showed the highest kappa coefficient (0.357), sensitivity (0.61), and negative predictive value (0.82). CONCLUSION: Based on the results of this study, the authors suggest that "Difficulty in walking around one lap of a 400-m track without help" may be the best question to use when evaluating slow gait speed.

Moderate hearing loss is related with social frailty in a community-dwelling older adults: The Korean Frailty and Aging Cohort Study (KFACS).

OBJECTIVES: To determine whether hearing loss is associated with social frailty in older adults. METHODS: Cross-sectional analysis of cohort study data. Hearing was measured using of Pure-tone audiometry. Hearing loss was determined based on the average of hearing thresholds at 0.5, 1, and 2 kHz in the ear that had better hearing. Social frailty was defined based on the summation of the following 5 social components (1. Neighborhood meeting attendance 2. Talking to friend(s) sometimes 3.Someone gives you love and affection 4. Living alone 5. Meeting someone every day). Participants who had no correspondence to the components were considered non-social frailty; those with 1-2 components were considered social prefrailty; and those having 3 or more components were considered social frailty. RESULTS: The prevalence of non-social frailty, social prefrailty, social frailty was 27.6%, 60.7% and 11.7% respectively. Of the five questions, two components (Neighborhood meeting attendance and Presence of someone who shows love and affection to the participants) were associated with hearing loss (p < 0.001). Compared to non-social frailty, the odds ratio of social frailty for hearing loss was 2.24 (95% CI 1.48-3.38) after adjusting for age, residential area, economic status, smoking, depressive disorder and MMSE, and 2.17 (95% CI 1.43-3.30) after further adjustments with physical frailty. CONCLUSION: Hearing loss was associated with social frailty even after controlling confounding factors even including physical frailty.

Recruiting Adolescents from Medicaid Enrollment Files into a Neighborhood Oral Health Study.

INTRODUCTION: Strategies are needed to improve recruitment of low-income adolescents into oral health studies. OBJECTIVES: In this study, we assessed the feasibility of recruiting Medicaid-enrolled adolescents into a neighborhood-level oral health study using Medicaid enrollment files and to evaluate the degree of bias in the final recruited study population. METHODS: We obtained Medicaid enrollment files from the Oregon Health Authority for 15,440 Medicaid enrollees aged 12 to 17 y from Multnomah, Hood River, and Tillamook counties. We attempted to contact the primary caregiver of each adolescent by telephone, and we tracked contact, recruitment, enrollment, and study completion rates. We further assessed if these rates were different across county-level rurality, neighborhood-level income, and caregiver-level language preference (Spanish vs. English). The Pearson chi-square test was used to compare rates (α = 0.05). We contacted 6,202 caregivers (40.2%), recruited 738 adolescents (11.9%), enrolled 335 (45.4%), and had complete data for 284 (84.8%). The overall enrollment yield from contacted caregivers was 5.4%. Contact rates did not differ significantly by rurality (P = 0.897), but they were significantly lower in the lowest-income neighborhoods (P = 0.023). Recruitment rates were significantly higher for adolescents from rural counties (P = 0.001), but they did not differ by income or language preference. Enrollment rates were significantly higher among adolescents from rural counties (P < 0.001) and were significantly associated with income (P = 0.041), but they were not different by language preference (P = 0.083). Among participants with complete data, there were no differences by rurality or income, but a significantly larger proportion of adolescents with complete data had caregivers with a language preference for Spanish (P = 0.043). RESULTS AND CONCLUSIONS: It is feasible to recruit Medicaid-enrolled adolescents into a neighborhood oral health study through the use of Medicaid files. County-, neighborhood-, and caregiver-level factors may influence characteristics of the final study population. Additional research is needed to improve recruitment of Medicaid enrollees into neighborhood oral health studies. KNOWLEDGE TRANSFER STATEMENT: Researchers can use the results of this study to plan neighborhood-level oral health studies involving recruitment of low-income adolescents. Findings further underscore the importance of assessing factors related to recruitment to evaluate participant bias and the generalizability of study findings.

Mid-term outcomes and complications of total knee arthroplasty in haemophilic arthropathy: A review of consecutive 131 knees between 2006 and 2015 in a single institute.

INTRODUCTION: Although total knee arthroplasty (TKA) in haemophilic arthropathy can reduce severe joint pain and improve functional disability, it is technically demanding. AIM: To evaluate mid-term outcomes and complications of TKA in haemophilic arthropathy. METHODS: This study retrospectively reviewed 131 consecutive primary TKAs in a single institute. The mean age was 41.0 years old, and the mean follow-up period was 6.8 years. Clinical and radiographic results were evaluated. Complications were categorized according to the classification system of the Knee Society for TKA complications. RESULTS: The average Western Ontario and McMaster Universities Arthritis Index (WOMAC) score improved from 66.0 to 24.2. The average flexion contracture significantly decreased from 17.3° to 4.7°, but the average pre- and postoperative maximum flexion did not differ (80.9° vs 85.6°, respectively). The average mechanical axis was varus 5.2° preoperatively and valgus 0.3° postoperatively. The coronal positions of the femoral and tibial components and the sagittal positions of these components were within ±3° in 83.2%, 89.3%, 63.4% and 73.3% of cases, respectively. Complications occurred in 17 knees (13.0%): hemarthrosis (n = 7), medial collateral ligament injury (n = 1), stiffness (n = 2), deep periprosthetic joint infection (PJI) (n = 3) and periprosthetic fracture (n = 4). CONCLUSIONS: The mid-term results of TKA in haemophilic arthropathy were satisfactory in pain relief, improved function and decreased flexion contracture. Bleeding and PJI continue to be major concerns for TKA in haemophilic arthropathy, and risk of periprosthetic fracture must be taken into account for patient education and appropriate prevention.

Detection of clinically occult primary tumours in patients with cervical metastases of unknown primary tumours: comparison of three-dimensional THRIVE MRI, two-dimensional spin-echo MRI, and contrast-enhanced CT.

AIM: To evaluate and compare the utility of contrast-enhanced three-dimensional (3D) T1-weighted high-resolution isotropic volume examination (THRIVE), spin-echo (SE) T1-weighted magnetic resonance imaging (MRI), and computed tomography (CT) for detecting clinically occult primary tumours in patients with cervical lymph node metastases. MATERIALS AND METHODS: Seventy-three consecutive patients with tumours that went undetected during endoscopic or physical examinations underwent preoperative contrast-enhanced CT and MRI (SE and 3D THRIVE) after gadolinium injection. Guided biopsy results served as reference standards. The diagnostic performances of the imaging techniques were compared with McNemar's tests. RESULTS: Primary tumours were identified in 59 (80.8%) of the 73 patients after surgery. Of these, 36 were found in the palatine tonsil, 11 in the base of the tongue, seven in the nasopharynx, and five in the pyriform sinus. The sensitivity (72.9%) and accuracy (71.2%) of 3D THRIVE for detecting primary tumours were higher than were those of SE T1-weighted MRI (49.2% and 53.4%, p≤0.002) or CT (36.4% and 46.4%, p≤0.001). The specificities of these techniques did not differ. The diagnostic performance of 3D THRIVE (area under the curve [AUC]=0.681) for detecting tumours did not differ from that of SE T1-weighted MRI or CT (AUC=0.671 and 0.608, p>0.05). CONCLUSION: 3D THRIVE was more sensitive at detecting primary tumours than was SE T1-weighted MRI or CT in patients with cervical metastases of unknown primary tumours. This sequence may improve biopsy and therapeutic planning in these patients.

Identification of major dietary patterns in Korean adults and their association with cancer risk in the Cancer Screening Examination Cohort.

BACKGROUND/OBJECTIVES: Cancer is the primary cause of disease-related death in Korea. The purposes of this study were to confirm the major dietary patterns and to evaluate whether there were associations between these identified dietary patterns and the risk of cancer based on data from the Cancer Screening Examination Cohort (CSEC) 2004-2008 of the National Cancer Center (NCC) of Korea. SUBJECTS/METHODS: This study included 8 024 subjects who completed a written survey on demographics and lifestyles, as well as a 3-day dietary record. Dietary patterns were identified by factor analysis using the principal component analysis method. The associations between the identified dietary patterns and cancer risk were examined using Cox proportional hazards regression models. RESULTS: During a median follow-up period of 9.0 years, 425 cancer cases were newly diagnosed. We identified 4 major dietary patterns ('rice and kimchi', 'vegetables and fish', 'fruits and dairy', and 'meats and sweets'). There was a negative relation between 'rice and kimchi' pattern and the risk of non-gastrointestinal cancers only (highest vs. lowest tertile; multivariate-adjusted hazard ratio=0.60, 95% confidence interval=0.41, 0.88). The 'fruits and dairy' pattern tended to decrease the risk of cancer, and the preventive effect was noted only for gastrointestinal cancer risk. However, there was no association after adjusting for covariates. CONCLUSIONS: The traditional dietary pattern with high consumption of rice, kimchi, soybean paste and vegetables may decrease the cancer risk among Koreans, and strategies based on the dietary pattern may effectively reduce the cancer risk.

Prognostic Value of Labyrinthine 3D-FLAIR Abnormalities in Idiopathic Sudden Sensorineural Hearing Loss.

BACKGROUND AND PURPOSE: According to recent research, modern MR imaging can detect the presense of abnormalities on labyrinthine. Our aim was to report the patterns and prognostic role of abnormal findings on labyrinthine imaging in patients with sudden sensorineural hearing loss. MATERIALS AND METHODS: This study comprised 113 patients who were diagnosed with unilateral sudden sensorineural hearing loss and underwent 3T MR imaging, including pre-/postcontrast 3D fluid-attenuated inversion recovery and T1-weighted imaging. We analyzed abnormalities on MR imaging and correlated them with audiometric results. RESULTS: Thirty-one (27%) patients showed abnormal findings on labyrinthine MR imaging in the affected ear. The initial/final hearing levels of the MRI+ group (91 ± 25/73 ± 27 dB hearing loss) were significantly worse than those of the MRI- group (69 ± 30/48 ± 24 dB hearing loss). The incidence of abnormalities on labyrinthine MR imaging was significantly lower (3 of 40, 8%) in 40 patients with initial mild-to-moderate hearing loss than in those with profound hearing loss (16 of 34, 47%). Considering hearing improvement by the Siegel criteria, the rate of complete or partial recovery was significantly higher in the MRI- group (34%) than in the MRI+ group (10%). In patients with initial severe or profound hearing loss, the MRI- group showed greater hearing improvement (38 ± 21 dB) than the MRI+ group (23 ± 22 dB). CONCLUSIONS: Abnormalities on labyrinthine MR imaging were found in 27% of patients with sudden sensorineural hearing loss. The initial hearing loss was worse in the MRI+ group than in the MRI- group. In patients with initial severe and profound hearing loss, the presence of abnormalities on labyrinthine MR imaging indicated a poor prognosis.

Survival Benefit of Early Cancer Detection Through Regular Endoscopic Screening for De Novo Gastric and Colorectal Cancers in Korean Liver Transplant Recipients.

BACKGROUND: De novo malignancy is not uncommon after liver transplantation (LT). Gastric cancer is one of the most common malignancies in both the Korean general population and LT recipients, and colorectal cancer prevalence is gradually increasing. METHODS: Among 3690 adult recipients who underwent LT from January 1999 and December 2013, the screening patterns and prognosis of 26 cases of gastric cancer and 22 cases of colorectal cancer were analyzed. RESULTS: For gastric cancer, the mean patient age was 54.6 ± 6.2 years at LT and 59.5 ± 6.7 years at cancer diagnosis, with a post-transplant interval of 60.2 ± 29.8 months. Patients were divided into regular (n = 18) and non-regular (n = 8) screening groups, with early cancer found in 14 and 0 patients; their 2-year survival rates after cancer diagnosis were 93.1% and 33.3% (P = .006), respectively. Endoscopic resection was successfully performed in 8 patients, all in the regular screening group. For colorectal cancer, the mean patient age was 53.3 ± 6.1 years at LT and 58.1 ± 6.7 years at cancer diagnosis, with a post-transplant interval of 54.3 ± 38.0 months. Patients were divided into regular (n = 19) and non-regular (n = 3) screening groups, with early cancer found in 12 and 0 patients; their 2-year survival rates after cancer diagnosis of 92.3% and 33.3% (P = .003), respectively. Endoscopic resection was successfully performed in 6 patients, all in the regular screening group. CONCLUSIONS: LT recipients are strongly advised to undergo regular screening studies for various de novo malignancies, especially cancers common in the general population. Regular endoscopic screening contributes to the timely detection of gastric and colorectal cancers, improving post-treatment survival outcomes.

In-situ Hybridization for the Detection of Sacbrood Virus in Infected Larvae of the Honey Bee (Apis cerana).

The aim of this study was to develop and use in-situ hybridization (ISH) for the detection and localization of the sacbrood virus (SBV) in Korean honey bee (Apis cerana) larvae that were infected naturally with SBV. A 258 base pair cDNA probe for SBV was generated by polymerase chain reaction. Cells positive for viral genome typically showed a dark brown reaction in the cytoplasm. SBV was detected consistently in trophocytes and urocytes. The ISH was successfully applied to routinely fixed and processed tissues and thus should prove helpful in the diagnosis and characterization of viral distribution in infected larvae.

Quantitative analysis of gains and catch-up saccades of video-head-impulse testing by age in normal subjects.

OBJECTIVES: To evaluate video-head-impulse test (vHIT) results in normal subjects, to determine the normative values of vHIT for the vestibulo-ocular reflex (VOR) and to characterise the catch-up saccades (CSs). DESIGN: Prospective cohort study. SETTING: Tertiary care academic referral centre. PARTICIPANTS: Fifty healthy subjects with no history of vestibular impairment, ten each in their 20's, 30's, 40's, 50's and 60's, underwent vHITs in the lateral semicircular canal plane. MAIN OUTCOME MEASURES: vHIT gains and the incidence and amplitudes of covert and overt CSs. RESULTS: The mean vHIT gain was 1.02 ± 0.07, and the mean gain asymmetry was 2.39 ± 1.96%, with no significant differences among age groups. CSs were observed during 22.6% of the trials and in 49% of the ears. The incidence of CSs was not associated with age. The mean velocity of CSs was 55.5 ± 16.9°/s, and its mean interaural difference was 11.8 ± 10.7°/s. CONCLUSIONS: vHIT gains were consistently equal to 1.0 in all age groups (20's to 60's), suggesting that abnormal criteria for vHIT gain (e.g. 0.8) and gain asymmetry (e.g. 8%) can be used, regardless of age. CSs were observed in about half of normal ears, suggesting that VOR is a hypometric system. The amplitudes and interaural difference of CSs were also similar in all age groups, suggesting that abnormal criteria for CS amplitude (e.g. 100°/s) and interaural difference (e.g. 40°/s) can be used, regardless of age.

How much related to skin wrinkles between facial and body site? Age-related changes in skin wrinkle on the knee assessed by skin bioengineering techniques.

BACKGROUND/PURPOSE: Skin aging has been focused the wrinkle on the face than on the body, so most studies have been studied the change in Crow's feet for ages. Only little is known about the age-dependent changes of wrinkles on body sites. The aim of this study was to establish new grading criteria for severity of wrinkles on knees and to investigate the relationship of wrinkle severity with age- and site-dependent. METHODS: The skin on the knee of 38 healthy Korean female volunteers, divided into two groups young and old, were photographed. Standard photograph for body wrinkle was established (grade 0~7), and then visual assessment, skin wrinkle, and skin elasticity were evaluated on Crow's feet and the knee. We examined for any significant differences and the correlation of skin aging parameters with age and two different sites. RESULTS: Skin wrinkle severity with standard photograph and wrinkle parameters (Ra, Rmax, Rz, and Rv) had a significantly positive correlation with age-dependent on the knee (P < 0.001). Also, skin elastic parameters (R2, R5, R6, R7, and Q1) showed a significant negative correlation with age on the knee (P < 0.001). Skin wrinkle severity with standard photograph was highly correlated with all skin wrinkle parameters and skin elastic parameters (R2, R5, R7, and Q1) on the knee (P < 0.001). In addition, all the skin aging parameters on the knee were significantly correlated with Crow's feet (P < 0.01). Skin aging on the knee had the same tendency as the Crow's feet. CONCLUSIONS: This study has shown the new grading criteria of wrinkles on the knee. Skin wrinkle and elasticity on the knee are age-dependent related and aging on the knee is highly related to Crow's feet. Those parameters are using a quantitative method to evaluate body aging. Also, the knee is considered that it could be a suitable site to evaluate body aging.

Cementless total hip arthroplasty for haemophilic arthropathy: follow-up result of more than 10 years.

The improvement of prophylaxis and adequate replacement of clotting factors, the quality of life and natural history of haemophilia have been significantly improved. However, significant functional impairment is inevitable. This study was performed to evaluate over 10 years clinical and radiographic outcomes of cementless total hip arthroplasty (THA) for treatment of haemophilic hip arthropathy. Between 1995 and 2003, 27 cases of cementless total hip arthroplasties were performed in 23 haemophilic patients. A total of 21 cases from 17 patients were available for follow-up analysis over 10 years. Modified Harris hip score, the range of motion of the hip joint, perioperative coagulation factor requirements and complications associated with bleeding were evaluated as part of the clinical assessment. For the radiographic assessment, fixation of component, osteolysis, loosening and other complications were evaluated. Clinically, the mean Harris hip score improved from 57 points before the operation to 94 points at the last follow-up. The mean flexion contracture was 10° preoperatively and 0.9° at the final follow-up. The further flexion improved from 68.4° to 90.5° after surgery. The mean monthly requirement of factor VIII reduced from 3150 units before surgery to 1800 units at the time of the last follow-up. There were three cases of rebleeding. In one case, a progressive haemophilic pseudotumour was found. Reoperation for any reason including revision was performed in three cases. We believe that cementless THA in patient with haemophilic hip arthropathy can bring reliable pain relief and functional improvement for longer than 10 years.

Determination of fourteen sunscreen agents in cosmetics using high-performance liquid chromatography.

OBJECTIVE: Commercial sunscreens consist of various compounds ranging from inorganic mineral pigments to organic chemical absorbents to achieve the required degree of protection against sunlight. However, the UV radiation screening ingredients have side effects. In this study, therefore, to ensure compliance with the maximum permissible chemical concentrations in sunscreen cosmetic products, a simultaneous and improved determination method for sunscreen chemicals was assessed. METHODS: Waters 2690 separations module HPLC system equipped with a Waters 486 tunable absorbance detector (UV-visible detector) has been employed and optimized to detect 14 compounds. For the separation, a Waters C18 column (5 µm, 4.6 mm i.d. 150 mm) and 1% of 0.1 M phosphoric acid in ethanol (solvent A) and in distilled water (solvent B) as mobile phases were used. RESULTS: The correlation coefficients of 14 standard mixture solutions exceeded 0.9993 in the range 2.5-200 µg mL(-1). The intra- and interday recovery and precision (relative standard deviation) of the method were 90.91-109.98% and within 10%, respectively, indicating that the developed method could provide reliable, precise and reproducible data. The detection limit was determined to be 0.01-1.99 µg mL(-1), and the quantization limit was determined to be 0.02-6.02 µg mL(-1), which were relatively lower than previous studies. CONCLUSION: This method was highly optimized in terms of selectivity, reproducibility and efficiency for the detection of 14 compounds. The validation data indicated that the improved method was quite suitable for their quantitative analysis of commercial product samples. Therefore, this method was applied to the determination of 14 compounds in commercial sunscreen cosmetic products. We verified that the amounts of sunscreen ingredients in the five currently sold sunscreens were >0.5% and within the designated limit, which means those could produce the safe and desired sunscreen effects on the skin. The present method could be applied to effectively monitor the process management and quality control of the cosmetics that are sold in the market.

Vertical components of head-shaking nystagmus in vestibular neuritis, Meniere's disease and migrainous vertigo.

OBJECTIVES: To describe vertical and horizontal components of head-shaking nystagmus (HSN) in various vestibular disorders. DESIGN: Retrospective case review. SETTING: Tertiary care academic referral centre. PARTICIPANTS: Head-shaking nystagmus was assessed in 66 vestibular neuritis (VN) patients at acute (<7 days) and follow-up (2 months), and 65 Meniere's disease (MD) and 76 migrainous vertigo (MV) in interictal period. MAIN OUTCOME MEASURES: Head-shaking nystagmus was categorised as pure horizontal, pure vertical or mixed. Horizontal HSN was classified as monophasic or biphasic and paretic or recovery. Vertical HSN was classified as upbeat or downbeat. RESULTS: Abnormal HSN (pathologic monophasic, biphasic or delayed-peak HSN) showed different positive rates depending on the vestibular disorders and compensation (94% in acute VN; 89% in FU VN; 78% in MD; 50% in MV). Paretic HSN with the nystagmus towards the lesioned side was the most common type in VN and MD; however, recovery HSN with the nystagmus towards the intact side could be rarely observed especially in patients with MD or compensated VN. Vertical nystagmus could be combined with horizontal HSN, and upbeat HSN was observed in most (83%) of the patients with acute VN, but downbeat HSN was common in follow-up VN (83%), MD (97%) and MV (85%). Weak perverted HSN, which is assumed to be a central nystagmus, was rarely observed in MD and MV (6-9%), but not in VN. CONCLUSIONS: Head-shaking nystagmus (HSN) in horizontal plane is a valuable tool in the assessment of vestibular imbalance. Common observation of upbeat HSN in acute VN and downbeat HSN in follow-up VN, MD and MV suggests that vertical components are possibly related to the involvement of vestibular apparatus and compensation. Weak perverted HSN and delayed-peak HSN were rarely observed in MD and MV, and never observed in VN, suggesting that it is possibly related to either asymmetrically impaired vertical canals or misorientation of the velocity-storage system.