Jeong Hee Cho

Distribution of the corticobulbar tract in the internal capsule

It is generally thought that the corticobulbar tract descends through the genu of the internal capsule (IC). There have been several reports that genu lesions cause bulbar symptoms such as facial palsies, dysarthria, and dysphagia. However, the precise location of the corticobulbar tract in the IC remains controversial. The purpose of our study is to assess whether the corticobulbar tract passes through the IC genu. We reviewed 26 patients with selective IC infarction and located the sites related to bulbar symptoms. In addition, using diffusion tensor imaging, we reconstructed tracts passing through the IC in ten subjects without cerebral infarction. Patients with genu infarction, which extended to more than half of the posterior limb of the IC, showed bulbar symptoms. However, patients with genu infarction, which was limited to the genu, did not have bulbar symptoms. In contrast, patients with lesions limited to the posterior limb may show bulbar symptoms. According to statistical maps of the region of interest, the lesions related to bulbar symptoms were localized to areas that were beyond the midpoint of the posterior limb of the IC. In diffusion tensor imaging of subjects without cerebral infarctions, the corticobulbar and corticospinal tracts did not pass through the IC genu. Our data provide evidence that the corticobulbar tract does not pass through the IC genu. The proposed location of the corticobulbar tract in the level of the IC lies beyond the midpoint of the posterior limb.

Subcortical vascular dementia (SVaD) without hypertension (HTN) may be a unique subtype of vascular dementia (VaD)

Although HTN is the most important factor in the pathogenesis of SVaD, about 20% of patients with SVaD do not have HTN. We hypothesize that SVaD without HTN may have strong risk factors other than HTN, and the study on this group can elucidate the risk factors for SVaD. We included 332 patients with SVaD from the database of the Clinical Research Center for Dementia of South Korea (CREDOS) study. Among them, 26.2% of patients (87 out of 332) had no history of HTN. We analyzed the differences in risk factors, clinical features, and survival time of SVaD according to HTN. Contrary to our expectations, SVaD without HTN had less known vascular risk factors such as diabetes mellitus (DM), dyslipidemia, and obesity. In addition, SVaD without HTN had different clinical features including less depression, focal neurological signs or symptoms and more features of disinhibition. However, although SVaD without HTN had less known vascular risk factors that can shorten survival times, the survival times did not differ according to the presence of HTN. SVaD without HTN may be a unique subtype of SVaD and can be a target group for studies of unknown risk factors for SVaD.

A Case of Isolated Middle Cerebral Artery Stenosis with Hemichorea and Moyamoya Pattern Collateralization

Isolated middle cerebral artery (MCA) stenosis in young patients with no other medical condition may be a unique pathologic entity with a benign long-term course. Generally, moyamoya disease shows a progression of stenosis from internal cerebral artery (ICA) to other intracranial vessel. A 26-year-old woman was admitted for choreic movements of the right arm and leg. Brain magnetic resonance imaging showed no stroke. Conventional angiography revealed 48% stenosis of the left M1 without ICA stenosis. Single photon emission computed tomography revealed perfusion asymmetry after acetazolamide injection, suggesting decreased uptake in the left basal ganglia and the cerebral cortex. Her hemichorea was mildly decreased with risperidone. One year later, follow-up angiography showed complete occlusion of the left M1 with neovascularization suggestive of moyamoya disease. The patient underwent bypass surgery and her hemichorea disappeared. This may be an atypical presentation of moyamoya disease. The bypass surgery was an effective measure for restoring the vascular insufficiency and, resultantly, controlling her hemichorea.

Cerebrospinal Biomarker Cut-off Methods Defined Only by Alzheimer's Disease Predict More Precisely Conversions of Mild Cognitive Impairment

Background and Purpose The cerebrospinal fluid (CSF) biomarkers play an important supportive role as diagnostic and predictive indicators of Alzheimers disease (AD). About 30% of controls in old age show abnormal values of CSF biomarkers and display a higher risk for AD compared with those showing normal values. The cut-off values are determined by their diagnostic accuracy. However, the current cut-off values may be less accurate, because controls include high-risk groups of AD. We sought to develop models of patients with AD, who are homogenous for CSF biomarkers. Methods We included participants who had CSF biomarker data in the Alzheimers Disease Neuroimaging Initiative database. We investigated the factors related to CSF biomarkers in patients with AD using linear mixed models. Using the factors, we developed models corresponding to CSF biomarkers to classify patients with mild cognitive impairment (MCI) into high risk and low risk and analyzed the conversion from MCI to AD using the Cox proportional hazards model. Results APOE ε4 status and age were significantly related to CSF Aβ1-42. CSF t-tau, APOE ε2 status and sex were significant factors. The CSF p-tau181 was associated with age and frequency of diagnosis. Accordingly, we modeled the three CSF biomarkers of AD. In MCI without APOE ε4, our models were better predictors of conversion. Conclusions We can interpret CSF biomarkers based on the models derived from the data obtained from patients with AD.