Dai-Seg Bai

Comparison of TMS and DTT for predicting motor outcome in intracerebral hemorrhage

BACKGROUND TMS (transcranial magnetic stimulation) and DTT (diffusion tensor tractography) have different advantages in evaluating stroke patients. TMS has good clinical accessibility and economical benefit. On the contrary, DTT has a unique advantage to visualize neural tracts three-dimensionally although it requires an expensive and large MRI machine. Many studies have demonstrated that TMS and DTT have predictive values for motor outcome in stroke patients. However, there has been no study on the comparison of these two evaluation tools. In the current study, we compared the abilities of TMS and DTT to predict upper motor outcome in patients with ICH (intracerebral hemorrhage). METHODS Fifty-three consecutive patients with severe motor weakness were evaluated by TMS and DTT at the early stage (7-28 days) of ICH. Modified Brunnstrom classification (MBC) and the motricity index of upper extremity (UMI) were evaluated at onset and 6 months after onset. RESULTS Patients with the presence of a motor evoked potential (MEP) in TMS or a preserved corticospinal tract (CST) in DTT showed better motor outcomes than those without (p=0.000). TMS showed higher positive predictive value than DTT. In contrast, DTT showed higher negative predictive value than TMS. CONCLUSIONS TMS and DTT had different advantages in predicting motor outcome, and this result could be a reference to predict final neurological deficit at the early stage of ICH.

Motor outcome prediction using diffusion tensor tractography in pontine infarct

We investigated whether the integrity of the corticospinal tract classified by diffusion tensor tractography (DTT) can predict the motor outcome in 25 patients with pontine infarct. DTTs were obtained in the early stage of stroke (5–30 days) and were classified into two groups (type A: the integrity of corticospinal tract was preserved around the infarct; type B: corticospinal tract was interrupted). DTT type A patients showed better motor function than the type B patients at 6 months after onset. DTT obtained at the early stage of pontine infarct appears to have predictive value for motor outcome in patients with pontine infarct. Ann Neurol 2008

The Effect of Premorbid Demographic Factors on the Recovery of Neurocognitive Function in Traumatic Brain Injury Patients

OBJECTIVE Premorbid demographic backgrounds of injured individuals are likely to reflect more accurately the status of patients with traumatic brian injury (TBI) than clinical factors. However, the concrete study about the relationship between the demographic factors and neurocognitive function in TBI patients has not been reported. The object of this study was to evaluate the effect of premorbid demographic factors on the recovery of neurocognitive function following TBI. METHODS From July 1998 to February 2007, 293 patients (male: 228, female: 65) with a history of head injury, who had recovered from the acute phase, were selected from our hospital to include in this study. We analyzed the effect of premorbid demographic factors including age, sex, educational level and occupation on the recovery of neurocognitive function in each TBI subgroup as defined by Glasgow Coma Scale (GCS) score. Intelligence and memory are components of neurocognitive function, and the Korean Wechsler Intelligence Scale (K-WAIS) and the Korean memory assessment scale (K-MAS) were used in this study. The results were considered significant at p<0.05. RESULTS The higher level of education was a good prognostic factor for intelligence regardless of GCS score and younger age group showed a better result for memory with an exception of severe TBI group. In the severe TBI group, the meaningful effect of demographic factors was not noted by the cause of influence of severe brain injury. CONCLUSION The demographic factors used in this study may be helpful for predicting the precise prognosis and developing an appropriate rehabilitation program for TBI patients.

Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature

Objective Physical or mental imbalance caused by harmful stimuli can induce stress to maintain homeostasis. During chronic stress, the sympathetic nervous system is hyperactivated, causing physical, psychological, and behavioral abnormalities. At present, there is no accepted standard for stress evaluation. This review aimed to survey studies providing a rationale for selecting heart rate variability (HRV) as a psychological stress indicator. Methods Term searches in the Web of Science®, National Library of Medicine (PubMed), and Google Scholar databases yielded 37 publications meeting our criteria. The inclusion criteria were involvement of human participants, HRV as an objective psychological stress measure, and measured HRV reactivity. Results In most studies, HRV variables changed in response to stress induced by various methods. The most frequently reported factor associated with variation in HRV variables was low parasympathetic activity, which is characterized by a decrease in the high-frequency band and an increase in the low-frequency band. Neuroimaging studies suggested that HRV may be linked to cortical regions (e.g., the ventromedial prefrontal cortex) that are involved in stressful situation appraisal. Conclusion In conclusion, the current neurobiological evidence suggests that HRV is impacted by stress and supports its use for the objective assessment of psychological health and stress.

Memory Dysfunctions after Mild and Moderate Traumatic Brain Injury : Comparison between Patients with and without Frontal Lobe Injury

OBJECTIVE The purpose of this study was to assess memory dysfunction in patients with mild and moderate traumatic brain injury (TBI) with and without frontal lobe injury (FLI). METHODS The subjects were 110 TBI patients, who had recovered from the acute clinical phase, and comprised 20 (18.2%) mild TBI (MTBI) patients with FLI, 16 (14.5%) MTBI patients without FLI, 51 (46.4%) moderate TBI (MOTBI) patients with FLI and 23 (20.9%) MTBI patients without FLI. All patients were administrated the Korean version of the Memory Assessment Scale (K-MAS). RESULTS Almost all the Summary Scale scores on the K-MAS failed to show any differences between TBI patients with and without FLI, but differences did emerge by types at severities. TBI patients with FLI showed higher Global Memory ability than TBI patients without FLI if their TBI was only mild, but when their TBI was more severe, this finding was reversed, and TBI patients with FLI showed lower Verbal and Global Memory abilities than TBI patients without FLI. CONCLUSION Different kinds of assessment tools are needed for the measurement of memory abilities in TBI patients with FLI, and that the selection of the appropriate tool depends on the severity of the TBI.

Prognostic Factors of Neurocognitive and Functional Outcomes in Junior and Senior Elderly Patients with Traumatic Brain Injury Undergoing Disability Evaluation or Appointed Disability Evaluation

Objective This study explored the relationships among demographic (DVs) and clinical variables (CVs), neurocognitive (NOs) and functional outcome (FO) that could be used as prognostic factors for old aged patients with traumatic brain injury (TBI) undergoing or appointed disability evaluation (DE) after treatment. Methods A total of 162 subjects with TBI above the age of 55 years undergoing DE or appointed to do so after treatments were selected. The patients were divided into two subgroups according to age : a junior elderly group 55 to 64 years old and a senior elderly group over the age of 65. NOs and FO were evaluated using the Seoul Neuropsychological Screening Battery and Clinical Dementia Rating scale. Results Gender, age, and education level were shown to significantly impact the recovery of NOs after TBI. Other DVs and CVs such as area of residency, occupation, type of injury, or loss of consciousness were not found to significantly affect the recovery of NOs after TBI. Analysis of the relationships among DVs, CVs and NOs demonstrated that gender, age, and education level contributed to the variance of NOs. In FO, loss of consciousness (LOC) was included to prognostic factor. Conclusion Gender, age and education level significantly influence the NOs of elderly patients with TBI. LOC may also serve as a meaningful prognostic factor in FO. Unlike younger adult patients with TBI, old aged patients with TBI did not show global faking-bad or malingering attitudes to DE for compensation, but assume that they could faking their performance in a test set available visual feedback.

Validation of a Paper and Pencil Test Battery for the Diagnosis of Minimal Hepatic Encephalopathy in Korea

The aim of this study was to validate a new paper and pencil test battery to diagnose minimal hepatic encephalopathy (MHE) in Korea. A new paper and pencil test battery was composed of number connection test-A (NCT-A), number connection test-B (NCT-B), digit span test (DST), and symbol digit modality test (SDMT). The norm of the new test was based on 315 healthy individuals between the ages of 20 and 70 years old. Another 63 healthy subjects (n = 31) and cirrhosis patients (n = 32) were included as a validation cohort. All participants completed the new paper and pencil test, a critical flicker frequency (CFF) test and computerized cognitive function test (visual continuous performance test [CPT]). The scores on the NCT-A and NCT-B increased but those of DST and SDMT decreased according to age. Twelve of the cirrhotic patients (37.5%) were diagnosed with MHE based on the new paper and pencil test battery. The total score of the paper and pencil test battery showed good positive correlation with the CFF (r = 0.551, P < 0.001) and computerized cognitive function test. Also, this score was lower in patients with MHE compared to those without MHE (P < 0.001). Scores on the CFF (32.0 vs. 28.7 Hz, P = 0.028) and the computer base cognitive test decreased significantly in patients with MHE compared to those without MHE. Test-retest reliability was comparable. In conclusion, the new paper and pencil test battery including NCT-A, NCT-B, DST, and SDMT showed good correlation with neuropsychological tests. This new paper and pencil test battery could help to discriminate patients with impaired cognitive function in cirrhosis (registered at Clinical Research Information Service [CRIS], https://cris.nih.go.kr/cris, KCT0000955).