Joong Koo Kang

Regional grey matter abnormalities in juvenile myoclonic epilepsy: a voxel-based morphometry study.

Visual assessment of structural MRI is, by definition, normal in patients with juvenile myoclonic epilepsy (JME), a major subsyndrome of idiopathic generalized epilepsy (IGE). However, recent quantitative MRI studies have shown structural abnormalities in cortical and thalamic grey matter (GM) in JME. Voxel-based morphometry (VBM) is a fully automated, unbiased, operator-independent MRI analysis technique that detects regionally specific differences in brain tissue composition on a voxel-wise comparison between groups of subjects. Using VBM, we examined structural differences in cortical and subcortical GM volume (GMV) between 25 JME patients (15 women, mean age=22.7+/-5.1 years) and age- and sex-matched 44 control subjects (27 women, mean age=23.1+/-4.3 years). We also performed a correlation analysis to delineate a possible relationship between the GMV increases or reductions and the increasing duration of epilepsy. Group comparison showed GMV increases in the superior mesiofrontal region bilaterally and GMV reductions in the thalamus bilaterally in JME patients (P<0.05, corrected for multiple comparisons using false discovery rate). Correlation analysis revealed that bilateral thalamic GMV had negative correlations with the duration of epilepsy (P<0.05, corrected for multiple comparisons after small volume corrections; P<0.05, Pearson correlation test). Our findings of GMV increases in the superior mesiofrontal regions and progressive thalamic atrophy could further support the pathophysiological concept of the functional abnormalities in thalamocortical circuit in JME.

Rapid Diagnosis of Tuberculous Meningitis by T Cell—Based Assays on Peripheral Blood and Cerebrospinal Fluid Mononuclear Cells

BACKGROUND The role of the new Myocbacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay for diagnosis of tuberculous meningitis (TBM) has not yet been fully assessed. Here, we conducted a prospective, blinded, observational study to evaluate the diagnostic accuracy of this assay, compared with the conventional tests, for diagnosing TBM. METHODS All adult patients with suspected TBM were enrolled at a tertiary care hospital (Seoul, South Korea) during a 12-month period. ELISPOT assays were performed on peripheral mononuclear cells and mononuclear cells from cerebrospinal fluid (CSF). RESULTS Eighty-nine patients with suspected TBM were enrolled. Of these, 31 (35%) were classified as having TBM (10 confirmed, 6 highly probable, and 15 probable cases), and 55 (62%) were classified as not having active tuberculosis. The remaining 3 (3%) with possible TBM were excluded from the final analysis. The sensitivities and specificities, respectively, of the tested methods for diagnosing TBM were as follows: CSF adenosine deaminase level >5.8 U/L, 89% (95% confidence interval [CI], 69%-98%) and 73% (95% CI, 58%-84%); peripheral mononuclear cells ELISPOT, 71% (95% CI, 51%-86%) and 57% (95% CI, 42%-70%); and CSF mononuclear cells ELISPOT assay, 59% (95% CI, 36%-79%) and 89% (95% CI, 72%-98%). The combined sensitivity of an adenosine deaminase level >5.8 U/L or a positive peripheral mononuclear cells ELISPOT assay result was 94% (95% CI, 79%-99%), conferring a negative likelihood ratio of 0.14 (95% CI, 0.03-0.55) when both test results were negative. CONCLUSION ELISPOT assays using peripheral mononuclear cells and CSF mononuclear cells are useful adjuncts to the current tests for diagnosing TBM, particularly when used in combination with the assessment of adenosine deaminase level in CSF.

Risk Factors for Central Pontine and Extrapontine Myelinolysis following Orthotopic Liver Transplantation

Background: Central pontine myelinolysis (CPM)/extrapontine myelinolysis (EPM) is one of the most serious neurological complications that can occur after orthotopic liver transplantation (OLT). We analyzed the risk factors for CPM/EPM in OLT patients. Methods: We retrospectively reviewed the records of 1,247 patients who underwent OLT between 1992 and 2005. We compared demographic, clinical and biological parameters of patients with CPM/EPM with those of age-, sex- and operation date-matched patients without CPM/EPM (controls). Results: Of 1,247 patients, 11 (0.88%) were diagnosed with CPM/EPM based on neuroimaging findings. A higher Model for End-Stage Liver Disease-Na score, preoperative hyponatremia and hypocholesterolemia, as well as greater changes in electrolytes, especially sodium, during surgery, were observed in the CPM/EPM group (p < 0.05). Conclusion: CPM/EPM after OLT is more likely to occur in patients with more severe preoperative liver dysfunction and greater changes in electrolyte imbalance, especially sodium, during surgery.

Changes in glucose metabolism and metabolites during the epileptogenic process in the lithium-pilocarpine model of epilepsy

Purpose:  The metabolic and biochemical changes that occur during epileptogenesis remain to be determined. 18F‐Fluorodeoxyglucose positron emission tomography (FDG‐PET) and proton magnetic resonance spectroscopy (1H MRS) are noninvasive techniques that provide indirect information on ongoing pathologic changes. We, therefore, utilized these methods to assess changes in glucose metabolism and metabolites in the rat lithium‐pilocarpine model of epilepsy as markers of epileptogenesis from baseline to chronic spontaneous recurrent seizures (SRS).

Spatiotemporospectral characteristics of scalp ictal EEG in mesial temporal lobe epilepsy with hippocampal sclerosis

The aim of present study was to identify the common propagation pattern of ictal discharges in mesial temporal lobe epilepsy (TLE). Pre-surgical ictal scalp EEG recordings were collected from patients with TLE associated with hippocampal sclerosis. Two types of ictal onset patterns were identified based on spatial and spectral characteristics of initial ictal discharge waveforms: (a) a sustained regular 5- to 9-Hz rhythm with a restricted temporal or subtemporal distribution (type 1); and (b) an irregular 2- to 5-Hz rhythm with a widespread distribution (type 2). Scalp EEG data were decomposed into temporally independent, spatially fixed component by independent component analysis. The identified source activities corresponding to ictal discharges from each seizure were localized by dipole source localization, and dipole sources with similar spatial locations were clustered. To identify the sequence of propagation among component clusters during the progress of seizures, event-related spectral perturbation by wavelet transform was used. Fifty-five seizures (22 seizures in four Type 1 patients and 33 seizures in eight Type 2 patients) in 12 patients were analyzed. Ictal discharges associated with type 1 seizures arose from both the anterior temporal region and basal ganglia, and then spread into medial frontal region. The dominant frequency of ictal rhythm was in the theta range and remained relatively constant until the middle portion of seizures. Type 2 seizures developed bilaterally or predominantly in the ipsilateral medial temporal region, followed by the medial frontal region and basal ganglia. The dominant frequency of ictal activity at the onset of seizure was in the delta range. However, rhythmic theta activities with decreasing tendency ensued rapidly after seizure onset. These findings suggest that TLE associated with hippocampal sclerosis may have preferential propagating patterns according to the type of the ictal onset pattern.

Ictal Hyperperfusion Patterns in Relation to Ictal Scalp EEG Patterns in Patients with Unilateral Hippocampal Sclerosis: A SPECT Study

Summary:  Purpose: The aims of the present study were to explore the relation between ictal scalp EEG patterns and ictal hyperperfusion patterns in patients with unilateral hippocampal sclerosis–associated mesial temporal lobe epilepsy (HS‐MTLE) by using semiquantitative single‐photon emission computed tomography (SPECT) analysis and to assess clinical significance of ictal hyperperfusion patterns.

Factors predicting seizure outcome of anterior temporal lobectomy for patients with mesial temporal sclerosis

PURPOSE To investigate the factors, including those associated with ictal scalp EEG results, related to surgical outcome in patients with pathologically proven mesial temporal sclerosis. METHODS We studied 51 consecutive patients who underwent anterior temporal lobectomy and had at least 4 years of follow-up. Surgical outcome was classified as being seizure-free or not seizure-free during the first two and the subsequent two postoperative years. Clinical variables and scalp EEG parameters were subjected to statistical analysis. RESULTS Of the 51 patients, 36 (70.6%) were seizure-free during postoperative years 3 and 4. Logistic regression analysis revealed that seizure remission for the first 2 years (p = 0.002) and contralateral propagated ictal discharges (p = 0.015) were independently related to seizure outcome at 4 years. Patients who were seizure-free at 2 years had an 86.5% chance of remaining seizure-free at 4 years. Of the patients without bitemporal asynchrony or switch of lateralization, 88.9% were seizure free at 4 years, compared with 54.5% of patients with asynchrony or switch of lateralization (p = 0.007). These two factors, however, were not predictive of seizure outcome at 2 years. CONCLUSIONS Contralateral propagated ictal discharges, including bitemporal asynchrony and switch of lateralization, unfavorably influence long-term seizure outcome. Long-term seizure control is best when the patient has no such propagation patterns of ictal discharges and is seizure-free during the first 2 years after temporal lobectomy.

Relationship between hypometabolic patterns and ictal scalp EEG patterns in patients with unilateral hippocampal sclerosis: An FDG―PET study

This study was to explore the relationship between scalp ictal EEG patterns and interictal hypometabolic patterns in hippocampal sclerosis-associated mesial temporal lobe epilepsy (HS-MTLE) and determine the clinical significance of interictal hypometabolic patterns. Twenty-five patients were classified into 2 groups based on initial ictal discharge (IID) frequency on scalp EEG: (a) those with a sustained regular 5- to 9-Hz rhythm with a restricted temporal or subtemporal distribution (group 1, N=9); and (b) those with an irregular 2- to 5-Hz rhythm with a widespread distribution (group 2, N=16). Using statistical parametric mapping, the PET results of each group were compared with age- and sex-matched controls to identify regions of significant hypometabolism, and the clinical characteristics were compared. Group 1 showed focal hypometabolism confined to the ipsilateral temporal lobe, whereas group 2 showed widespread hypometabolism in the ipsilateral temporal lobe, insular cortex and anterior part of the putamen. The two groups showed no significant differences in clinical characteristics. Among semiologic features, dystonic limb posturing was more frequently observed in group 2 (p=0.03). In summary, scalp EEG IID patterns in HS-MTLE can be important in determining hypometabolic patterns on interictal PET. Differences in hypometabolic patterns may reflect preferential pathways of ictal propagation rather than intrinsic epileptogenic regions.

Comparison of clinical manifestations, outcomes and cerebrospinal fluid findings between herpes simplex type 1 and type 2 central nervous system infections in adults.

In previous reports on the viral causes of central nervous system (CNS) infections, it has been generally recognized that HSV‐1 is a major cause of encephalitis, while HSV‐2 is the predominant cause of aseptic meningitis in adults. To examine this matter, the clinical characteristics in the two types of HSV CNS infections were investigated. In a retrospective cohort study which included all adult patients (≥16 years) between January 1999 and December 2013 in a 2,700‐bed tertiary care hospital, all the patients in whom PCR of the CSF for HSV was positive were identified. Ninety‐five patients with positive CSF PCR results for HSV were included, 21 with HSV‐1 and 74 with HSV‐2. Many patients with HSV‐1 had encephalitis (13/21, 61.9%), whereas most patients with HSV‐2 had meningitis (62/74, 83.8%). However, HSV‐1 and HSV‐2 accounted for similar proportion of patients with HSV encephalitis (13/25, 52.0% vs. 12/25, 48.0%). Neurological sequelae were more frequent among patients with HSV‐1 (9/21, 42.9% vs. 6/74, 8.1%; P = 0.001). The present study suggests that HSV‐2 is not only a major cause of aseptic meningitis, but also it may cause serious manifestation as HSV‐1 encephalitis in adults. J. Med. Virol. 86: 1766–1771, 2014.

Vasogenic Edema in a Case of Hypercalcemia-Induced Posterior Reversible Encephalopathy

160 hypotension, resulting in dilation of intracranial veins. This latter situation might give rise to symmetrical subdural haematomas [2] . This type of haematoma should not be considered a benign condition, since up to 44% of them may become complicated with progressive deterioration of consciousness and life-threatening symptoms, requiring an urgent surgical evacuation. However, surgery is sometimes not enough to improve the patient’s condition, and an epidural blood patch is often needed [3] . We have the impression that lumbar puncture is not considered an aggressive manoeuvre, mainly among physicians in training, but although it is not usually a dangerous procedure, clinicians should keep in mind that it should be performed only when necessary.