Systemic Sarcoidosis Presenting as Bilateral Optic Neuritis

Sarcoidosis is a multi-systemic inflammatory disease in which non-caseating granuloma occur in different sites producing variable clinical symptoms. Although it can involve various organs including brain and orbits, bilateral optic neuritis as the first symptom of systemic sarcoidosis is rare. Sarcoidosis is a diagnostic challenge, especially if systemic symptoms are absent. We report a patient who presented bilateral optic neuritis as the first manifestation of systemic sarcoidosis without other systemic symptoms including cranial neuropathies or intraocular involvement.

A 4-Year Follow-Up of Subjects with Visually Equivocal Amyloid Positron Emission Tomography Findings from the Alzheimer’s Disease Neuroimaging Initiative Cohort / 대한핵의학회잡지

Background@#To date, the clinical significance of visually equivocal amyloid positron emission tomography (PET) has not been well established. @*Objective@#We studied the clinical significance of equivocal amyloid PET images from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). @*Methods@#Subjects with F-18 florbetapir PET scans at baseline who were followed up for 4 years were selected. Clinical characteristics, imaging biomarkers, cognitive function, and rate of conversion to AD were compared in subjects with visually equivocal findings. @*Results@#Of 249 subjects who completed the follow-up, 153 (61.4%), 20 (8.0%), and 129 (30.5%) were F-18 florbetapir-negative, -equivocal, and -positive, respectively. The mean standardized uptake value ratios (SUVR) of F-18 florbetapir PET were 0.75 ± 0.04, 0.85 ± 0.10, and 1.00 ± 0.09 for each group (p <0.001 between groups), and 15.0%, 70.0%, and 98.7% of patients were quantitatively above the positive threshold. The change in the SUVR of F-18 florbetapir PET was higher in the equivocal (6.09 ± 3.61%, p <0.001) and positive (3.13 ± 4.38%, p <0.001) groups than the negative group (0.88 ± 4.28%). Among the subjects with normal or subjective memory impairment and mild cognitive impairment, 5.3% with negative amyloid PET and 37.5% with positive amyloid PET converted to AD over the 4-year period. None of the equivocal amyloid PET subjects converted to AD during this period.

Two Cases of Myasthenia Gravis Showing Fatigibility Presenting with Decreased Gain of Smooth Pursuit / 대한평형의학회지

Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies to the acetylcholine receptors of the neuromuscular junction characterized by weakness and abnormal fatigability of the muscles. Therefore, the diagnosis of MG depends on the recognition of this distinctive pattern of fatigable weakness. Previous studies presented the diagnostic efficacy of saccadic eye movements in patients with ocular MG. We here in report 2 patients of ocular MG showing the fatigue effects during repetitive sustained smooth pursuit, and the effects of the administration of edrophonium on myasthenic smooth pursuit. Changes in smooth pursuits reflecting peripheral and secondary central mechanisms were demonstrated.

Visuospatial Dysfunction in Patients With the Right Vestibular Neuritis / 대한평형의학회지

Acute vestibular neuritis (VN) is characterized by acute/subacute vertigo with spontaneous nystagmus and unilateral loss of semicircular canal function. Vestibular system in human is represented in the brain bilaterally with functional asymmetries of the right hemispheric dominance in the right handers. Spatial working memory entails the ability to keep spatial information active in working memory over a short period of time which is also known as the right hemispheric dominance. Three patients (patient 1, 32-year-old female; patient 2, 18-year-old male; patient 3, 63-year-old male) suffered from acute onset of severe vertigo, nausea and vomiting. Patients 1 and 2's examination revealed VN on the right side showing spontaneous left beating nystagmus and impaired vestibular ocular reflex on the right side in video head-impulse and caloric tests. Patient 3's finding was fit for VN on the left side. We also evaluated visuospatial memory function with the block design test in these 3 VN patients which discovered lower scores in patients 1 and 2 and the average level in patient 3 compare to those of healthy controls. Follow-up block design test after resolved symptoms showed within normal range in both patients. Our cases suggest that the patients with unilateral peripheral vestibulopathy may have an asymmetrical effect on the higher vestibular cognitive function. The right VN can be associated with transient visuospatial memory dysfunction. These findings add the evidence of significant right hemispheric dominance for vestibular and visuospatial structures in the right-handed subjects, and of predominant dysfunction in the hemisphere ipsilateral to the peripheral lesion side.

Clinical Heterogeneity of Anti-GM2-Ganglioside-Antibody Syndrome

BACKGROUND AND PURPOSE: Antiganglioside antibodies are known to play a pathogenic role in Guillain-Barré syndrome (GBS). Either an immunoglobulin (Ig)G- or IgM-type anti-GM2 antibody is detected in rare cases in GBS patients. However, the specific pathogenic role of these antibodies in GBS has not been reported previously. This study aimed to define and characterize the clinical spectrum of GBS with anti-GM2 positivity. METHODS: We reviewed the database of the Dong-A University Neuroimmunology Team, which has collected sera of GBS and its variants from more than 40 general and university-based hospitals in Korea. Detailed information about the involved patients was often obtained and then corrected by the charge doctor applying additional questionnaires. RESULTS: Four patients with acute monophasic peripheral neuropathy or cranial neuropathy with isolated IgM-type anti-GM2-antibody positivity were recruited. In addition, IgG-type anti-GM2 antibody was solely detected in the sera of another four patients. The IgM-positive group comprised heterogeneous syndromes: two cases of acute motor axonal neuropathy, one of acute inflammatory demyelinating polyneuropathy, and one of isolated facial diplegia. In contrast, all of the cases enrolled in the IgG-positive group manifested with dizziness with or without oculomotor palsy due to cranial neuropathy syndrome. CONCLUSIONS: This study has identified that anti-GM2 antibody can be found in various subtypes of GBS and its variants in rare cases. Compared to the clinical heterogeneity of the IgM-positive group, the IgG-positive group can be characterized by cranial-dominant GBS variants presenting mainly with oculomotor and vestibular dysfunctions.

Focal Subarachnoid Hemorrhage Mimicking Recurrent Transient Ischemic Attack

Focal subarachnoid hemorrhage occasionally presents as transient focal neurologic episodes mimicking transient ischemic attack (TIA). Unless properly diagnosed, it may aggravate cerebral hemorrhage by administering antithrombotic agents. Therefore, clinicians need to be aware that such focal subarachnoid hemorrhage sometimes cannot be detected on noncontrast computed tomography and blood-sensitive magnetic resonance imaging can detect even a small amount of hemorrhage. We describe an 85-year-old woman with focal subarachnoid hemorrhage and possible cerebral amyloid angiopathy who presented transient left arm weakness recurrently, which mimicked TIA.

Superior Altitudinal Visual Field Defect as Initial Manifestation of Posterior Reversible Encephalopathy Syndrome

No abstract available.

Epilepsy and Driving Regulation in Korea

In Korea, current status of epilepsy and driving are challenging and there are lack of formal legal guidelines about driving in patients with epilepsy. According to the default standards in Korean Road Traffic law, patients with epilepsy are restricted or prohibited from driving except who are conditionally allowed to drive by the Aptitude Judgement Committee (AJC). Though the AJC consist of medical doctors and traffic officials, new regulation and guidelines are required for various type of seizure and characteristics of patients with epilepsy. This review outlines the current applicable legislation about epilepsy and driving in Korea as well as that of the overseas country calling for new laws to establish a consistent assessment.

Superior Oblique Myokymia Associated with Neurovascular Cross Compression

Superior oblique myokymia (SOM) is a rare disorder characterized by unilateral paroxysmal oscillopsia or diplopia. Recent studies revealed that SOM can be associated with neuro-vascular cross compression (NVCC) of the trunk of the trochlear nerve. Although it frequently occurs without any underlying systemic disease or concurrent neurologic sign, we need to consider this NVCC especially in cases with persistent disturbing symptoms. Hereby, we present two cases of SOM whose neuroimaging studies suggest NVCCs and, discuss recent update of the pathomechanism of SOM.

Parasomnia as an Initial Presentation of Narcolepsy

Narcolepsy is characterized by excessive daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucinations. Only a few studies have focused on non-rapid eye movement (NREM) and REM parasomnias in narcolepsy. We report a narcolepsy without cataplexy patient presenting parasomnia as an initial symptom. A 18-year-old boy was admitted to hospital for abnormal behavior of sitting up during sleep over 2 years. He had a symptom of lethargy without cataplexy and subjective excessive daytime sleepiness, but his family found him often asleep during daytime. He underwent 3 times of polysomnography (PSG) including 1 multiple sleep latency test (MSLT) after the last PSG. The last PSG showed 1 episode of abrupt sitting. Three sleep REM onset period was observed in MSLT which was not detect in PSG. Parasomnia as an initial symptom of narcolepsy is a rare clinical entity. The MSLT may be useful in the evaluation of patients with parasomnia and unexplained hypersomnia.

Classification of Chronic Dizziness in Elderly People and Relation with Falls / 대한평형의학회지

OBJECTIVES: Fall is a major cause of morbidity and mortality among older adults. Falls result from many various causes, and dizziness is important risk for falls, especially in the elderly. Research on the relationship between chronic dizziness and falls in elderly people has been rarely performed and these were no studies that analyzed the risk of falls according to subtypes of chronic dizziness. METHODS: We conducted a prospective study of the association between subtypes of chronic dizziness and falls in the elderly between 65 to 75 years. We divided dizzy patients into 5 groups according to the results of symptom, vestibular and autonomic function test. Falls and new events (acute dizziness or other medical conditions) were checked monthly by telephone or out patient department follow-up for 6 months. RESULTS: Thirty-four patients were enrolled and all completed follow-up for 6 months. Nine patients classified as the falling groups and 34 patients as nonfalling group. Whereas the frequencies of orthostatic hypotension (n=6, 67%) and vestibular dysfunction (n=1, 11%) were higher in fall group, psychogenic dizziness (n=12, 35%), and vestibular migraine (n=3, 9%) were more frequent in nonfall group. CONCLUSIONS: The presence of dizziness in the elderly is a strong predictor of fall, especially orthostatic hypotension is an important predictor of fall. In order to lower the risk of falls in the elderly, an approach based on the cause of dizziness is needed.

Clinical Significance of Perverted Head-Shaking Nystagmus / 대한평형의학회지

OBJECTIVES: We investigated clinical significance of head shaking nystagmus (HSN) and perverted HSN (pHSN) in patients with peripheral and central vestibular disorders. METHODS: We reviewed medical records of 822 consecutive subjects who were referred to a dizziness clinic. We performed neurologic examination including video-oculography in darkness for 60 seconds before, during and for 100 seconds after head-shaking. HSN was considered to develop when post-head-shaking nystagmus last at least 5 beats with latency from end of head-shaking of no more than 5 seconds, and a velocity at least 3°/sec. RESULTS: In control group (n=45), there were observed spontaneous nystagmus (SN) in 2.2%, HSN in 17.8%, pHSN in 6.7%. In patients with peripheral vestibular disorder group (n=397), there were observed SN in 14.1%, HSN in 40.6%, pHSN in 9.8%. In patients with central vestibular disorder group (n=217), there were observed SN in 17.5%, HSN in 24.0%, pHSN in 13.4%. In unspecified dizziness group (n=208), there were observed SN in 1.9%, HSN in 13.0%, pHSN in 1.9%. pHSN was frequently observed in central vestibular disorders such as stroke, vestibular migraine, cerebellar ataxia, and vertebro-basilar insufficiency. However, pHSN was also observed at higher rate than expected in peripheral vestibular disorders including benign paroxysmal positional vertigo especially involving vertical canals, Meniere disease and even in unilateral vestibulopathy. CONCLUSIONS: Our results show that perverted HSN in dizzy populations was frequently observed not only in cases of central vestibular disorders but also in peripheral disorders. Perverted HSN can develop by any conditions that cause difference in vestibular velocity storage in vertical component of vestibular-ocular reflex.

Brain Hypometabolism in Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome / 대한평형의학회지

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a slowing progressive ataxic disorder characterized by bilateral vestibulopathy, cerebellar ataxia and somatosensory impairment. Autonomic dysfunction is recently considered as a core feature in CANVAS in addition to these symptoms. In most cases, patients with CANVAS show cerebellar atrophy in brain imaging, but some cases show minimal or no atrophy of cerebellum. Brain (18F)-fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) study can be a complimentary tool to diagnosis CANVAS in cases of no structural abnormality such as cerebellar atrophy. Hereby, we present a case of CANVAS with minimal atrophy of cerebellum but showing a prominent hypometabolism in cerebellum, thalamus and posterior cingulate cortex in ¹⁸F-FDG PET.

A Case of Partial Oculomotor Nerve Palsy Caused by Vascular Compression in Idiopathic Intracranial Hypertension / 대한평형의학회지

Pupil-involving oculomotor nerve palsy (ONP) is frequently associated with compressive lesion such as intracranial aneurysm originating from the posterior communicating arteries. Vascular variant of posterior intracranial circulation is regarded as an uncommon cause and association between these vascular variants and intracranial hypertension has not been reported. We present an 18-year-old girl with pupil-involving ONP combined with idiopathic intracranial hypertension who revealed compression of oculomotor nerve by a vascular variant of superior cerebellar artery (SCA). This is a rare case of an ONP attributed to compressive effect from an aberrant SCA affected by intracranial hypertension.

Four Cases of Wernicke's Encephalopathy with Impaired Horizontal Vestibular Ocular Reflexes / 대한평형의학회지

Wernicke's encephalopathy (WE) is a neurological disorder induced by a dietary vitamin B1 (thiamine) deficiency which is characterized by encephalopathy, gait ataxia, and variant ocular motor dysfunction. In addition to these classical signs of WE, a loss of the horizontal vestibulo-ocular reflex (VOR) is being reported as the major underdiagnosed symptoms in WE. In this retrospective single center study, we report four cases of WE initially presented with impaired horizontal VOR in addition to the classical clinical presentations, and imaging and neurotological laboratory findings were described.

Wernicke Encephalopathy Associated with Acute Wet Beriberi

Wernicke encephalopathy is usually accompanied with peripheral neuropathy, known as dry beriberi. In contrast, wet beriberi presenting as cardiovascular symptoms rarely occurs. The acute type of wet beriberi can be fatal, if untreated quickly. It is reported that the cerebellar vermis has a role of the coordination and control of cardiovascular and autonomic reflex activities. We report a 58-year-old man showing acute wet beriberi in Wernicke encephalopathy with cerebellar vermis lesion.

Magnetic Resonance Imaging Fails to Show Evidence of Endolymphatic Hydrops in a Case with Tumarkin's Otolithic Crisis

Tumarkin's otolithic crisis refers to drop attacks that are an unusual manifestation of Meniere's disease. It has been proposed that these drop attacks result from mechanical deformation of the otolithic organs related to the endolymphatic hydrops that occurs in Meniere's disease, as revealed by MRI with intratympanic gadolinium enhancement. Here we report a patient with Tumarkin's otolithic crisis in whom inner-ear MRI with intratympanic gadolinium administration during the acute attack did not reveal the presence of endolymphatic hydrops.

Simultaneous Recordings of Cervical and Ocular Vestibular-Evoked Myogenic Potentials

BACKGROUND: Cervical (cVEMP) and ocular (oVEMP) vestibular-evoked myogenic potentials are short-latency manifestations of vestibulo-ocular and vestibulocollic reflexes that originate from the utricle and saccule. The aim of this study was to determine whether simultaneously recording cVEMP and oVEMP more reliably detects the reflex responses than when making separate recordings. METHODS: Both simultaneous recordings and conventional separate recordings of the cVEMP and oVEMP responses to air-conducted tone bursts were obtained in 39 healthy subjects. p13 and n10 latencies, and p13-n23 and n10-p16 amplitudes of cVEMP and oVEMP waveforms were measured, respectively. The asymmetry ratios (ARs) of the amplitudes were calculated. RESULTS: In cVEMP testing, the p13 latencies and p13-n23 amplitudes did not differ significantly between simultaneous and conventional separate recordings. In oVEMP testing, the n10 latencies measured in simultaneous recordings showed a small but statistically significant prolongation compared to the results in separate recordings. Moreover, the n10-p16 amplitudes were significantly larger in the simultaneous recordings. The AR of simultaneous recordings of cVEMP and oVEMP did not differ between the two recording methods. CONCLUSIONS: Simultaneously recording cVEMP and oVEMP provides a reliable test and could be a clinically useful and simplified diagnostic tool for evaluating dizzy patients.

Simultaneous Recordings of Cervical and Ocular Vestibular-Evoked Myogenic Potentials

BACKGROUND: Cervical (cVEMP) and ocular (oVEMP) vestibular-evoked myogenic potentials are short-latency manifestations of vestibulo-ocular and vestibulocollic reflexes that originate from the utricle and saccule. The aim of this study was to determine whether simultaneously recording cVEMP and oVEMP more reliably detects the reflex responses than when making separate recordings. METHODS: Both simultaneous recordings and conventional separate recordings of the cVEMP and oVEMP responses to air-conducted tone bursts were obtained in 39 healthy subjects. p13 and n10 latencies, and p13-n23 and n10-p16 amplitudes of cVEMP and oVEMP waveforms were measured, respectively. The asymmetry ratios (ARs) of the amplitudes were calculated. RESULTS: In cVEMP testing, the p13 latencies and p13-n23 amplitudes did not differ significantly between simultaneous and conventional separate recordings. In oVEMP testing, the n10 latencies measured in simultaneous recordings showed a small but statistically significant prolongation compared to the results in separate recordings. Moreover, the n10-p16 amplitudes were significantly larger in the simultaneous recordings. The AR of simultaneous recordings of cVEMP and oVEMP did not differ between the two recording methods. CONCLUSIONS: Simultaneously recording cVEMP and oVEMP provides a reliable test and could be a clinically useful and simplified diagnostic tool for evaluating dizzy patients.

Prevalence of Anti-Ganglioside Antibodies and Their Clinical Correlates with Guillain-Barre Syndrome in Korea: A Nationwide Multicenter Study

BACKGROUND AND PURPOSE: No previous studies have investigated the relationship between various anti-ganglioside antibodies and the clinical characteristics of Guillain-Barre syndrome (GBS) in Korea. The aim of this study was to determine the prevalence and types of anti-ganglioside antibodies in Korean GBS patients, and to identify their clinical significance. METHODS: Serum was collected from patients during the acute phase of GBS at 20 university-based hospitals in Korea. The clinical and laboratory findings were reviewed and compared with the detected types of anti-ganglioside antibody. RESULTS: Among 119 patients, 60 were positive for immunoglobulin G (IgG) or immunoglobulin M antibodies against any type of ganglioside (50%). The most frequent type was IgG anti-GM1 antibody (47%), followed by IgG anti-GT1a (38%), IgG anti-GD1a (25%), and IgG anti-GQ1b (8%) antibodies. Anti-GM1-antibody positivity was strongly correlated with the presence of preceding gastrointestinal infection, absence of sensory symptoms or signs, and absence of cranial nerve involvement. Patients with anti-GD1a antibody were younger, predominantly male, and had more facial nerve involvement than the antibody-negative group. Anti-GT1a-antibody positivity was more frequently associated with bulbar weakness and was highly associated with ophthalmoplegia when coupled with the coexisting anti-GQ1b antibody. Despite the presence of clinical features of acute motor axonal neuropathy (AMAN), 68% of anti-GM1- or anti-GD1a-antibody-positive cases of GBS were diagnosed with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) by a single electrophysiological study. CONCLUSIONS: Anti-ganglioside antibodies were frequently found in the serum of Korean GBS patients, and each antibody was correlated strongly with the various clinical manifestations. Nevertheless, without an anti-ganglioside antibody assay, in Korea AMAN is frequently misdiagnosed as AIDP by single electrophysiological studies.