Man-Wook Seo

Cervical and ocular vestibular-evoked myogenic potentials in acute vestibular neuritis

OBJECTIVES To clarify the origin and afferent pathways of short-latency ocular vestibular-evoked myogenic potential (oVEMP) in response to air-conducted sound (ACS), we evaluated cervical (cVEMP) and ocular VEMPs in patients with vestibular neuritis (VN). METHODS In response to air-conducted tone burst, the oVEMP and cVEMP were measured in 60 healthy controls and in 41 patients with acute VN. The VN selectively involved the superior vestibular nerve (superior VN) in 30 patients, affected the inferior vestibular nerve only (inferior VN) in three and damaged both superior and inferior vestibular nerve branches in eight. RESULTS All 30 patients with superior VN presented normal cVEMPs, indicating preservation of the saccular receptors and their afferents in the inferior vestibular nerve. However, the oVEMP was abnormal in all patients with superior VN. By contrast, the patients with inferior VN showed normal oVEMP and abnormal cVEMP. CONCLUSION These dissociations in the abnormalities of cVEMP and oVEMP in patients with VN selectively involving the superior or inferior vestibular nerve suggest that the origin of the vestibular nerve afferents of oVEMP differ from those of cVEMP. SIGNIFICANCE The oVEMP in response to ACS may be mediated by the superior vestibular nerve, probably due to an activation of the utricular receptors.

Does waist indicate dyslipidemia better than BMI in Korean adult population

Obesity is an independent and modifiable risk factor for cardiovascular disease, and known as a core of the metabolic syndrome. Obesity has been largely diagnosed based upon anthrompometric measurements like waist circumference (WC) and body mass index (BMI). We sought to determine associations between anthropometric measurements and dyslipidemia in a community adult sample composed of 1,032 community residents (356 men, 676 women) aged 50 yr and over in Namwon, Korea. Blood tests for lipid profiles, including total cholesterol (TC) and HDL cholesterol (HDL) were performed, and dyslipidemia was defined as TC/HDL greater than 4. Anthropometric measurements included WC, waist-to-height ratio (WHtR), waist-to-hip ratio, and BMI. All anthropometric measures were categorized into quartiles and evaluated for associations with dyslipidemia. TC/HDL showed the significant associations with the anthropometric measures, independently of potential confounders. In women, increases of obesity indexes by quartile analyses showed linear increases of odds ratios for dyslipidemia (p values <0.01 by trend test). In men, except BMI, same patterns of association were noted. WC and WHtR were significantly associated with dyslipidemia in Korean adult population. As a simple and non-invasive method for a detection of obesity and dyslipidemia, anthropometric measurements could be efficiently used in clinical and epidemiologic fields.

Reversible Cerebellar Dysfunction Associated with Ciguatera Fish Poisoning

BACKGROUND Ciguatera-fish poisoning (or ciguatera) is a common but underdiagnosed food-borne illness related to fish consumption that is characterized by nausea, vomiting and neurologic symptoms such as tingling in the fingers or toes. OBJECTIVE We describe the case of a young man who suffered from diarrhea and abdominal pain after eating raw fish and who also developed severe ataxia with spontaneous downbeat and perverted head-shaking nystagmus. CASE REPORT The patient experienced visual fixation suppression failure during the bithermal caloric test and bilateral smooth-pursuit impairment. Oculomotor findings suggested dysfunction of the vestibulocerebellum, especially the flocculus. CONCLUSION These findings suggest that both the peripheral and the central nervous systems can be involved in ciguatera.

Relationship Between Essential Tremor and Cerebellar Dysfunction According to Age

Background The cerebellum and its neural circuitry have been assumed to play a major role in the pathophysiology of essential tremor (ET). In this study, we sought to find associations between ET and cerebellar dysfunction. Methods We performed tandem gait test in 41 ET patients and 44 age-matched controls. Investigators assessed tandem gait by counting the number of missteps during ten-step tandem walk and each subject repeated the trial three times. Results ET patients had a higher average and total numbers of missteps during tandem gait tests than control subjects (p<0.05). Sex-adjusted odds ratio of the association between tandem gait abnormality and ET was 3.40 (95% confidence intervals 1.06-10.85). According to age stratification, aged ET patients (age ≥70 years) showed significantly higher prevalence of tandem gait abnormality than young ones. Interaction terms determined by a likelihood ratio test was also statistically significant (p<0.05). Conclusions Dysfunction of cerebellar neural circuitry may be associated with the pathophysiological mechanism of ET. In addition, aging may be an important factor modifying the association.

Recurrent Streptococcus Pneumoniae Meningoencephalitis in a Patient With a Transethmoidal eningoencephalocele

We report a case of recurrent Streptococcus Pneumoniae meningoencephalitis with a transethmoidal meningoencephalocele (TEME) but without cerebrospinal fluid (CSF) leakage. A 35-year-old man was admitted with S. pneumoniae meningitis. He had suffered from four episodes of recurrent pneumococcal meningitis during the previous 4 years. A computed tomography scan of the paranasal sinus showed the TEME protruding through a bony defect of the right frontal base. However, the patient did not have symptoms that could be attributable to CSF leakage, and radioisotope cisternography did not identify a leak. Brain magnetic resonance imaging revealed cortical lesions overlying the TEME, and electroencephalography revealed epileptiform discharges in frontal regions. Appropriate antibiotics therapy without steroids was given to improve his condition. The presented case suggests that even in the absence of clinically demonstrable CSF leakage, an occult skullbase defect and its associated meningoencephalocele should be considered in patients with recurrent bacterial meningitis.

Extreme Duplication-type, Nonseparated Fenestration of the Basilar Artery in a Patient with Pontine Infarction: Confirmation with Virtual Arterial Endoscopy

We present a case of a 55-year-old woman with pontine infarction and fenestration of the basilar artery that was demonstrated using virtual endoscopy. The patient had motor weakness of the right side with sudden onset. Diffusion- and T2-weighted MR images revealed high signal intensities in the left pontine regions, and an MR angiographic examination showed the double-lumen sign of the basilar artery. An extensive duplication-type, nonseparated fenestration of the basilar artery was diagnosed by virtual endoscopy and craniocaudal communications with discrete openings were observed. We report a case of a patient with basilar artery fenestration and associated brainstem infarction.

Nonconvulsive status epilepticus presenting as epileptic nystagmus in a patient with herpes encephalitis.

Epileptic nystagmus (EN) is characterized by rhythmic ocular oscillations or quick, repetitive eye movements secondary to seizure activity. The fast component of EN is known to be contralateral to the epileptogenic focus. There are few reports EN occurring patients in nonconvulsive status epilepticus (NCSE). We report such a patient in the setting of herpes encephalitis.

Selective saccadic palsy after cardiac surgery.

We report a patient who showed a selective deficit of voluntary saccades and quick phases of nystagmus after cardiac surgery. Voluntary saccades in the horizontal plane were very slow, while vertical saccades, vestibular and optokinetic nystagmus, were absent. However, smooth pursuit, the vestibulo-ocular reflex, and the ability to hold steady eccentric gaze were preserved.

Ergotism With Ischemia In All Four Extremities: A Case Report

Here we describe a case of ergotism that presented with ischemia in all four extremities. A 48-year-old man was admitted for pain and weakness in both upper extremities. He had a long history of migraine and had taken 3 mg of ergotamine daily for more than 21 years. Angiography demonstrated vasospasm involving all four extremities, which resolved partially following intra-arterial prostaglandin infusion. Intravenous nitroprusside was administered, and the patient stopped smoking and stopped taking ergotamine in an attempt to counteract the vasospasm. Follow-up computed tomography angiogram revealed that both brachial arteries had normalized. Thus, in this case of ergotism, severe vasospasm in all of the extremities was resolved with appropriate management.

Paroxysmal ocular tilt reactions after mesodiencephalic lesions: Report of two cases and review of the literature

BACKGROUND To elucidate the mechanisms of paroxysmal ocular tilt reaction (OTR) from mesodiencephalic lesions by analyzing the associated ocular motor findings. METHODS Two patients with paroxysmal ipsiversive OTR due to mesodiencephalic lesions underwent evaluation of associated ocular motor abnormalities and one of them had three-dimensional recording of eye motion. We also reviewed previously reported six patients with paroxysmal OTR. RESULTS One patient showed contraversive torsional nystagmus during the paroxysms in association with vertical gaze limitation and vertical gaze-evoked nystagmus, which are consistent with baseline dysfunction and paroxysmal irritation of the interstitial nucleus of Cajal (INC) during the attacks. The other patient exhibited ipsiversive torsional nystagmus during the attacks, along with slowed vertical saccades and decreased amplitude of ipsitorsional nystagmus during the torsional vestibulo-ocular reflex between the attacks. These findings are best explained by underlying dysfunction and paroxysmal irritation of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). CONCLUSIONS The associated ocular motor findings in our patients indicate that paroxysmal ipsiversive OTR in mesodiencephalic lesions is caused by intermittent hyperactivity of partially damaged ipsilesional riMLF or INC.