Kwang-Dong Choi

Randomized clinical trial for geotropic horizontal canal benign paroxysmal positional vertigo

Objectives: To determine the immediate and long-term therapeutic efficacies of barbecue rotation and Gufoni maneuvers, a randomized, prospective, and sham-controlled study was conducted in patients with the geotropic type of benign paroxysmal positional vertigo involving the horizontal semicircular canal (HC-BPPV). Methods: In 10 nationwide dizziness clinics in Korea, 170 consecutive patients (107 women, age range 11−97 years, mean age ± SD 61 ± 15 years, median = 61 years) with geotropic HC-BPPV were randomly assigned to barbecue rotation (n = 56), Gufoni (n = 64), or sham maneuver (n = 50). An immediate response was determined within 1 hour after a maximum of 2 trials of each maneuver on the visit day. We also assessed the cumulative results of each maneuver by following up the patients for 1 month. Results: After a maximum of 2 maneuvers on the initial visit day, barbecue rotation (38 of 55 [69.1%]) and Gufoni (39 of 64 [60.9%]) maneuvers showed better responses than the sham maneuver (17 of 48 [35.4%]). The cumulative therapeutic effects were also better with barbecue rotation (p = 0.006) and Gufoni (p = 0.031) maneuvers than with the sham maneuver. However, therapeutic efficacies did not differ between the barbecue rotation and Gufoni groups in terms of both immediate (p = 0.46) and long-term (p = 0.10) outcomes. Conclusion: Using a prospective randomized trial, we demonstrated that barbecue rotation and Gufoni maneuvers are effective in treating geotropic HC-BPPV. Classification of evidence: This study provides Class I evidence that barbecue rotation and Gufoni maneuvers are effective in the treatment of geotropic HC-BPPV.

Vertigo in brainstem and cerebellar strokes.

PURPOSE OF REVIEW The aim of this study is to review the recent findings on the prevalence, clinical features, and diagnosis of vertigo from brainstem and cerebellar strokes. RECENT FINDINGS Patients with isolated vertigo are at higher risk for stroke than the general population. Strokes involving the brainstem and cerebellum may manifest as acute vestibular syndrome, and acute isolated audiovestibular loss may herald impending infarction in the territory of the anterior inferior cerebellar artery. Appropriate bedside evaluation is superior to MRI for detecting central vestibular syndromes. Recording of vestibular-evoked myogenic potentials is useful for evaluation of the central otolithic pathways in brainstem and cerebellar strokes. SUMMARY Accurate identification of isolated vascular vertigo is very important since misdiagnosis of acute stroke may result in significant morbidity and mortality, whereas overdiagnosis of vascular vertigo would lead to unnecessary costly work-ups and medication.

The vestibulo-ocular reflexes during head impulse in Wernicke's encephalopathy

Ocular motor findings in Wernicke’s encephalopathy (WE) include gaze evoked nystagmus (GEN), central positional nystagmus, weakness of abduction, internuclear ophthalmoplegia and horizontal or vertical gaze palsy to total ophthalmoplegia. Another feature of WE is vestibular paresis.1 2 Previous studies documented hypoactive vestibular responses to both caloric and rotational stimuli, and a short vestibulo-ocular reflex (VOR) time constant. To address differential susceptibility of individual semicircular canals (SCC) according to stimulation frequency, we measured high acceleration VOR of the individual SCC using head impulse manoeuvres, and the low frequency VOR using bithermal caloric and rotatory chair tests in two patients with WE. Figure 1 (A) T2 weighted MRIs of patient No 1. Symmetrical hyperintense lesions are shown at dorsal portions of both the medulla, periaqueductal gray matter and medial portions of both thalami. (B) Bithermal caloric tests in patient No 1 show minimal responses in both ears initially (B-1), which markedly improved 6 months after thiamine replacement (B-2)

Rotational Vertebral Artery Occlusion Mechanisms and Long-term Outcome

Background and Purpose— To elucidate the mechanisms and prognosis of rotational vertebral artery occlusion (RVAO). Methods— We analyzed clinical and radiological characteristics, patterns of induced nystagmus, and outcome in 21 patients (13 men, aged 29–77 years) with RVAO documented by dynamic cerebral angiography during an 8-year period at 3 University Hospitals in Korea. The follow-up periods ranged from 5 to 91 months (median, 37.5 months). Most patients (n=19; 90.5%) received conservative treatments. Results— All the patients developed vertigo accompanied by tinnitus (38%), fainting (24%), or blurred vision (19%). Only 12 (57.1%) patients showed the typical pattern of RVAO during dynamic cerebral angiography, a compression of the dominant vertebral artery at the C1-2 level during contralateral head rotation. The induced nystagmus was mostly downbeat with horizontal and torsional components beating toward the compressed vertebral artery side. None of the patients with conservative treatments developed posterior circulation stroke, and 4 of them (21.1%) showed resolution of symptoms during the follow-ups. Conclusions— RVAO has various patterns of vertebral artery compression, and favorable long-term outcome with conservative treatments. In most patients with RVAO, the symptoms may be ascribed to asymmetrical excitation of the bilateral labyrinth induced by transient ischemia or by disinhibition from inferior cerebellar hypoperfusion. Conservative management might be considered as the first-line treatment of RVAO.

MRI restricted diffusion in optic nerve infarction after autologous fat transplantation.

A 24-year-old woman reported blindness in the left eye upon awakening from fat autotransplantation to her forehead for soft tissue augmentation in the face. Clinical findings on the third postoperative day suggested ipsilateral ophthalmic artery occlusion with infarction of the optic nerve and retina. There were also clinical manifestations of a mild right hemiparesis. MRI diffusion-weighted imaging (DWI) revealed restricted diffusion of the left optic nerve and left middle cerebral artery domain indicative of the cytotoxic edema of infarction. This is the second report of optic nerve infarction after fat autotransplantation to the forehead and the first report of DWI restricted diffusion in this setting.

Pseudovestibular neuritis associated with isolated insular stroke.

Damage to the cerebellum or brainstem can often cause vestibular dysfunction. Although rare, central rotational vertigo following cerebral cortical lesions has also been reported [1, 4, 5, 7]. However, no report has documented objective nystagmus associated with central rotational vertigo in cortical stroke. We describe a patient with rotational vertigo who showed mixed horizontal and torsional spontaneous nystagmus mimicking peripheral vestibulopathy in isolated insular infarction. A 51-year-old woman presented with sudden onset of word finding difficulty. She had history of Hashimoto thyroiditis. On admission, neurological examinations were unremarkable. Brain magnetic resonance imaging (MRI) revealed an acute infarction in the left insula. Small parts of the frontal operculum were also involved (Fig. 1a). One day after symptom onset, her word finding difficulty had completely resolved and the Korean version of the Western Aphasia Battery was administered on the same day showed her overall language skills were normal (Aphasia Quotient = 82.0). However, the patient started to complain of rotational vertigo on the same day. Her vertigo occurred regardless of position change, which was not accompanied by nausea or vomiting. Neurological examinations on that day showed spontaneous right beating horizontal nystagmus. The line bisection test conducted on the second day of her vertigo onset showed bisection markers shifting to the left. Video-oculography performed 7 days after onset of vertigo revealed a right beating horizontal nystagmus mixed with a clockwise torsional component, which was augmented by horizontal head-shaking test (Fig. 1b). Head impulse test was normal. Bithermal caloric tests performed 8 days after vertigo onset revealed 18% canal paresis in the left ear. After that, her vertigo gradually resolved and she intermittently experienced rotational vertigo without any other symptoms, lasting 1 or 2 min, five times a month on average. Her electroencephalogram (EEG) taken during the course of the disease was normal. Follow-up bithermal caloric tests 6 months post stroke showed 14% canal paresis in the left ear. Her vertigo completely disappeared after 9 months post stroke. Follow-up computed tomography (CT) scan performed 17 months post stroke confirmed the lesion to be restricted to the left insula (Fig. 1c). The patient was admitted to our hospital, presenting with word finding difficulty, and her brain MRI showed acute infarction in the left insula. While her word finding difficulty disappeared 1 day after onset of stroke, she developed rotational vertigo. Her spontaneous nystagmus, i.e., a right beating horizontal nystagmus with a clockwise torsional component, suggested left vestibular neuritis (VN). However, normal head impulse test and small degree of canal paresis on bithermal caloric tests were not compatible with left VN, since typical unilateral VN shows positive head impulse test, and 25% or more difference of vestibular function between the affected and nonaffected B.-Y. Ahn J.-W. Bae K.-D. Choi E.-J. Kim (&) Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, 1-10 Ami-dong, Seo-gu, Busan 602-739, Korea e-mail: eunjookim@pusan.ac.kr

Acute Transient Vestibular Syndrome: Prevalence of Stroke and Efficacy of Bedside Evaluation.

Background and Purpose— The aim of this study was to determine the prevalence of stroke and efficacy of bedside evaluation in diagnosing stroke in acute transient vestibular syndrome (ATVS). Methods— We performed a prospective, single-center, observational study that had consecutively recruited 86 patients presenting with ATVS to the emergency department of Pusan National University Yangsan Hospital from January to December 2014. All patients received a constructed evaluation, including HINTS plus (head impulse, nystagmus patterns, test of skew, and finger rubbing) and brain magnetic resonance imagings. Patients without an obvious cause further received perfusion-weighted imaging. Multivariable logistic regression was used to determine clinical parameters to identify stroke in ATVS. Results— The prevalence of stroke was 27% in ATVS. HINTS plus could not be applied to the majority of patients because of the resolution of the vestibular symptoms, and magnetic resonance imagings were falsely negative in 43% of confirmed strokes. Ten patients (12%) showed unilateral cerebellar hypoperfusion on perfusion-weighted imaging without an infarction on diffusion-weighted imaging, and 8 of them had a focal stenosis or hypoplasia of the corresponding vertebral artery. The higher risk of stroke in ATVS was found in association with craniocervical pain (odds ratio, 9.6; 95% confidence interval, 2.0–45.2) and focal neurological symptoms/signs (odds ratio, 15.2; 95% confidence interval, 2.5–93.8). Conclusions— Bedside examination and routine magnetic resonance imagings have a limitation in diagnosing strokes presenting with ATVS, and perfusion imaging may help to identify strokes in ATVS of unknown cause. Associated craniocervical pain and focal neurological symptoms/signs are the useful clues for strokes in ATVS.

Isolated vestibular syndrome in posterior circulation stroke: Frequency and involved structures

SummaryDizziness/vertigo is a common symptom of posterior circulation stroke and usually accompanies other neurologic symptoms and signs. Although strokes involving the brainstem or cerebellum may produce isolated vestibular syndrome (isolated vertigo or imbalance), the overall frequency and involved structures of isolated vestibular syndrome in the posterior circulation stroke remain uncertain. Isolated vestibular syndrome occurs in approximately 25% of the patients with posterior circulation stroke, and mostly involves the cerebellum, inferior or superior cerebellar peduncles, and caudal lateral or rostral dorsolateral medulla. The occasional negative neuroimaging in patients with acute isolated vascular vertigo highlights the importance of appropriate bedside evaluation in acute vestibular syndrome.

Hemimacropsia after medial temporo-occipital infarction

Dysmetropsia is a disorder of visual perception characterised by an apparent modification of the size of perceived objects.1–3 Objects can appear larger (macropsia) or smaller (micropsia) than their actual size. Dysmetropsia can result from retinal oedema causing a dislocation of the receptor cells and from lesions affecting other parts of extracerebral visual pathways. Transient micropsia can also result from epileptic seizure, migraine, infectious mononucleosis, the action of mescaline and other hallucinogenic drugs, and psychopathological phenomena. Permanent dysmetropsia following focal cerebral lesions is rare. Most of the prior reports described hemimicropsia due to lesions mainly involving the lateral aspect of the visual association cortex.1–3 However, reports of hemimacropsia following focal cerebral lesions have been extremely rare1,4 and hemimacropsia following a focal vascular lesion has not been described previously. We describe a patient with left hemimacropsia due to right medial temporo-occipital infarction. A 64-year-old right-handed man with hypertension was admitted 4 days after a sudden onset of visual disturbance. He …

Neuroanatomical correlation of urinary retention in lateral medullary infarction

We prospectively recruited 10 patients who presented with urinary retention as a neurological deficit that was attributable to lateral medullary infarction. Of these, 9 patients underwent a urodynamic study, which demonstrated detrusor underactivity of the bladder in 7 patients. Urinary retention developed mainly when the lesions involved the lateral tegmentum of the middle or caudal medulla. We concluded that interruption of the descending pathway from the pontine micturition center to the sacral spinal cord in the lateral medulla was responsible for the development of urinary retention. Ann Neurol 2015;77:726–733