Kyungmi Oh

Interictal Metabolic Changes in Episodic Migraine: A Voxel-Based FDG-PET Study

Whereas there are many H2 15O-positron emission tomography (PET) studies demonstrating neuronal activation during acute migraine attacks, little information is available on the interictal (headache-free period) glucose metabolic changes in migraine. We therefore conducted voxel-based statistical parametric mapping analysis of 18F-fluorodeoxyglucose-PET to evaluate interictal metabolic differences between 20 episodic migraine patients (four with aura; three men; mean age 34.0 ± 6.4 years) and 20 control subjects. Separate correlation analyses were performed to delineate a possible relationship between regional glucose metabolism and disease duration or lifetime headache frequency in migraine patients. Group comparison showed that migraine patients had significant hypometabolism in several regions known to be involved in central pain processing, such as bilateral insula, bilateral anterior and posterior cingulate cortex, left premotor and prefrontal cortex, and left primary somatosensory cortex (uncorrected P < 0.001, corrected P < 0.05 with small volume corrections). Correlation analyses showed that regional metabolism of the insula and anterior cingulate cortex had significant negative correlations with disease duration and lifetime headache frequency (uncorrected P < 0.001, corrected P < 0.05 with small volume corrections). Our findings of progressive glucose hypometabolism in relation to increasing disease duration and increasing headache frequency suggest that repeated migraine attacks over time lead to metabolic abnormalities of selective brain regions belonging to the central pain matrix.

Altered thalamocortical functional connectivity in idiopathic generalized epilepsy.

Aberrant thalamocortical network has been hypothesized to play a crucial role in the fundamental pathogenesis underlying idiopathic generalized epilepsy (IGE). We aimed to investigate alterations of thalamocortical functional network in patients with IGE using thalamic seed‐based functional connectivity (FC) analysis, and their relationships with frontal cognitive functions and clinical characteristics.

The relationship of pain and health‐related quality of life in Korean patients with Parkinson’s disease

Background –  Parkinson’s disease (PD) is a chronic progressive neurodegenerative disorder. Increasing attention has been focused on the pain and health‐related quality of life (HrQOL) in patients with PD.

Prevalence and Risk Factors of Intracranial Atherosclerosis in an Asymptomatic Korean Population

Background and Purpose Intracranial atherosclerosis (ICAS) is one of the major risk factors for ischemic stroke, particularly in Asian populations. We investigated the prevalence and risk factors of ICAS in asymptomatic subjects. Methods We prospectively evaluated 835 asymptomatic Korean adults who voluntarily visited a tertiary referral hospital for a health screening examination that included brain magnetic resonance angiography. The subjects had no history of stroke or transient ischemic attacks; those who had potential cardiac sources of emboli were excluded. ICAS and extracranial atherosclerosis were defined as a reduction in luminal diameter of at least 50%. Vascular risk factors were screened through questionnaires, interviews, and examinations. Results ICAS was found in 25 subjects (3.0%) and extracranial atherosclerosis was found in 4 patients (0.5%). No patient had combined lesions. ICAS was distributed in 31 arteries in 25 subjects: anterior cerebral arteries (5 subjects, 16%), middle cerebral arteries (16 subjects, 52%), posterior cerebral arteries (8 subjects, 26%), and distal internal carotid arteries (2 subjects, 7%). The ratio of ICAS of the anterior circulation (23 of 31 arteries with ICAS, 74%) to that of the posterior circulation (8 of 31 arteries with ICAS, 26%) was 3:1. The ratio of ICAS (23 of 27 arteries with atherosclerosis in the anterior circulation, 85%) to extracranial atherosclerosis (4 of 27 arteries with therosclerosis in the anterior circulation, 15%) was 6:1. An older age [odds ratio (OR)=1.05, 95% confidence interval (CI)=1.00-1.10] and hypertension (OR=2.41, 95% CI=1.01-5.72) were independent risk factors for ICAS. Conclusions ICAS is more prevalent than extracranial atherosclerosis among neurologically asymptomatic Korean adults. Subjects with ICAS are significantly older and have an increased frequency of hypertension compared to those subjects without atherosclerotic stenosis.

C-reactive protein is a predictor of early neurologic deterioration in acute ischemic stroke.

Although the association between elevated C-reactive protein (CRP) level and long-term outcome after ischemic stroke is well known, the association between CRP and early neurologic deterioration (END) has not yet been thoroughly studied. We investigated the impact of CRP on END in patients with acute ischemic stroke. From a prospectively collected, multicenter stroke registry, 428 patients with acute ischemic stroke diagnosed within 24 hours of onset were enrolled in the study. Patients with hemorrhagic stroke, transient ischemic attack, and thrombolysis were excluded. END was defined as a >2-point increase in the National Institutes of Health Stroke Scale score within a 72-hour period. Data considered potentially associated with CRP level and the END were collected. END was observed in 47 patients. CRP level, time before arrival at the hospital, age, female sex, hematocrit, high-density lipoprotein (HDL) cholesterol level, hemoglobin A(1c) level, and internal carotid artery occlusion were significantly associated with END. On logistic regression analysis, CRP level, internal carotid artery occlusion, and HDL cholesterol proved to be independent variables. Our data suggest that CRP level at admission is significantly associated with END in acute ischemic stroke. HDL cholesterol and internal carotid artery occlusion are also associated with END.

Cutaneous silent period in patients with restless leg syndrome

OBJECTIVE To investigate the pathophysiological relationship between RLS and small fiber neuropathy using the cutaneous silent period (CSP), which is a spinal reflex mediated by Adelta cutaneous afferents and is useful for the evaluation of small-diameter nerve function. METHODS The CSP was measured from the extensor digitorum brevis in 157 patients with RLS and 60 healthy controls. The CSP measurement was repeated in the RLS patients after dopamine agonist treatment for one month. The RLS rating scale for clinical severity was used to evaluate each patient before and after treatment. The measured CSP variables were compared between the patient group and the control group. In addition, the possible correlation between the CSP variables and the RLS rating scale score related to treatment was analyzed. RESULTS The mean CSP latencies did not differ between the RLS patients and the healthy controls; however, the mean CSP duration was significantly longer in the RLS patients than in the controls, and this prolonged CSP duration improved to the level of the control subjects after dopamine agonist treatment (p=0.003). The mean RLS rating scale score also significantly decreased after medication (p=0.000). However, the changes in the CSP variables did not correlate with the decrement in the RLS rating scale score. CONCLUSIONS Although our results do not support the role of Adelta fiber dysfunction in RLS, the observed change in CSP duration may be useful as a clinical measure of the improvement with dopamine agonist treatment in patients with RLS. SIGNIFICANCE Further study is needed to elucidate the exact mechanism involved in the prolonged CSP duration in response to treatment.

Usefulness of a photophobia questionnaire in patients with migraine

Photophobia is an important criterion for the diagnosis of migraine. However, several Asian epidemiological surveys about migraine have shown lesser prevalence of photophobia than that of Western studies. This discrepancy is probably caused by underestimation of photophobia due to inappropriate questioning of patients by physicians. To investigate this issue, we developed a questionnaire about photophobia and evaluated its usefulness in 103 patients with migraine. In phase 1 of the study, we found good repeatability of the questionnaire with a 0.826 k coefficient. In phase 2, the prevalence of photophobia from interviews and that from the questionnaire were compared. The prevalence of interview-documented photophobia was 51.5% and of questionnaire-documented photophobia 82.5% (P < 0.001). In phase 3, we attempted to make a short-form questionnaire with the same detection power of the questionnaire study. Two short-form questionnaires were identified as a useful method for detecting photophobia. The prevalence of photophobia could be underreported via interview, especially in Asian migraineurs. Using this questionnaire to test for photophobia, the diagnostic rate of photophobia and migraine could be improved.

Combination of anxiety and depression is associated with an increased headache frequency in migraineurs: a population-based study.

BackgroundAlthough anxiety and depression have been classified as distinct traits of affective disorders, previous studies have reported their co-occurrence in subjects with migraine. However, few reports are available on the clinical implications of this comorbidity. This study is to assess the comorbidity of anxiety and depression in subjects with migraine and its clinical implications in a population-based sample from Korea.MethodsWe selected Korean subjects aged 19–69 years by the stratified random sampling method, and evaluated them using a semi-structured interview, designed to identify headache type, anxiety, and depression. We used Goldberg Anxiety Scale questions and Patient Health Questionnnaire-9 for the diagnosis of anxiety and depression, respectively.ResultsOf the 2,762 participants who completed the interview, 147 subjects (5.4%) were classified as having a migraine during the previous year. Among these 147 subjects, 17 (11.6%) had anxiety and depression, 28 (19.0%) had anxiety alone, 9 (6.1%) had depression alone, and 93 (63.3%) had neither anxiety nor depression. Headache frequency per month was remarkably higher in subjects having migraine with anxiety and depression (median [25–75 percentile values], 8.0 [2.5–21.0]) than in those having migraine with anxiety alone (2.0 [1.0–5.0], p = 0.003), migraine with depression alone (1.0 [0.3–4.0], p = 0.001), and migraine without anxiety or depression (1.0 [0.3–3.0], p < 0.001). The migraine with anxiety alone (7.0 [6.0–8.0], p = 0.011) group and migraine with anxiety and depression (7.0 [5.0–9.0], p = 0.018) group showed higher Visual Analogue Scale scores for pain intensity compare to migraine without anxiety or depression (6.0 [5.0-7.0]) group.ConclusionsApproximately 1/3 of migraineurs with anxiety had depression and 2/3 of migraineurs with depression had anxiety. Combination of anxiety and depression was associated with an increased headache frequency. Anxiety was associated with exacerbation of headache intensity.

Thickening of the somatosensory cortex in migraine without aura

Objective We aimed to explore cortical thickness abnormalities in a homogeneous group of patients with migraine without aura and to delineate possible relationships between cortical thickness changes and clinical variables. Methods Fifty-six female migraine patients without aura and T2-visible white matter hyperintensities and 34 female controls were scanned on a 3T magnetic resonance imager. Cortical thickness was estimated and compared between patients and controls using a whole-brain vertex-by-vertex analysis. Correlation analysis was conducted between cortical thickness of significant clusters and clinical variables. Results Compared to controls, migraine patients had cortical thickening in left rostral middle frontal gyrus and bilateral post-central gyri. Region-of-interest analysis revealed cortical thickening of bilateral post-central gyri in migraine patients relative to controls. The average thickness of bilateral post-central gyri positively correlated with disease duration as well as estimated lifetime headache frequency. Conclusions We have provided evidence for interictal cortical abnormalities of thickened prefrontal cortex and somatosensory cortex in female migraine patients without aura. Our findings of greater thickening of the somatosensory cortex in relation to increasing disease duration and increasing headache frequency suggest that repeated migraine attacks over time may lead to structural changes of the somatosensory cortex through increased noxious afferent input within the trigemino-thalamo-cortical pathway in migraine.

Postural instability and cognitive dysfunction in early Parkinson's disease

BACKGROUND Postural instability is one of the most disabling features of Parkinsons disease, usually occurring in late and advanced stages. The aim of this study was to investigate the postural performance of early-stage de novo Parkinsons disease patients with no clinical postural instability using computerized dynamic posturography. We sought to understand the relationship between postural sway and disease severity and the relationship between postural instability quantitatively measured by computerized dynamic posturography and cognitive impairment in early-stage Parkinsons disease patients. METHOD Thirty-one subjects with Parkinsons disease and 20 healthy controls were assessed by the computerized dynamic posturography protocol using the sensory organization test and the motor control test. A neuropsychological assessment was also administered. RESULTS The mean equilibrium score for sensory organization test and the vestibular input ratio were significantly correlated with Hoehn-Yahr stage. No associations between motor latency for any motor control test condition and Hoehn-Yahr stage were found. The equilibrium score for sensory organization test correlated with the mini-mental status examination scores. There was a significant correlation between motor latency for large backward translation and mini-mental status examination scores. There were significant correlations between visual perception/construction/ memory of the neuropsychological battery test and the equilibrium score for sensory organization test and between verbal word learning test, controlled word association test and motor latency for large backward translation. CONCLUSION These findings showed the postural instability present in early-stage (Hoehn-Yahr stage 2-2.5) Parkinsons disease. We also found a close relationship between postural instability and cognitive function in Parkinsons disease patients.