OBJECTIVES: To compare the white matter microstructure of dyslexic children with normal children using diffusion tensor imaging. METHODS: Twenty one dyslexic children and 24 normal control children were recruited in the second and third grade of elementary school students. The fractional anisotropy (FA) values of 20 representative white matter tracts were estimated from the diffusion tensor imaging data of each subject using the Johns Hopkins University-white matter tractography atlas to determine the difference in white matter integrity between the dyslexic children and normal children. RESULTS: Compared to the normal control group, the FA values of the left inferior longitudinal fasciculus [F(1,39)=5.908, p<0.05] and temporal part of the right superior longitudinal fasciculus [F(1,39)=7.328, p=0.010] were significantly higher in the dyslexic group and there was no significant difference in the other tracts. CONCLUSION: In dyslexic children, compensatory pathways develop in the left inferior longitudinal fasciculus and in the temporal part of the right superior longitudinal fasciculus.
Anisotropy ; Case-Control Studies ; Child ; Diffusion Tensor Imaging ; Dyslexia ; Humans ; White Matter

Background: and Purpose: The increased demand for donor organs has made it crucial to keep the organs of patients with impending brain death (PWIBDs) suitable for transplantation during the process of determining brain death. This study aimed to identify the time taken to determine brain death (TT-BD) in PWIBDs and the associated influencing factors. Methods: This study analyzed data collected by the Korean Organ Donation Agency from 15 hospitals in the Yeongnam region of South Korea. There were 414 PWIBDs eligible for inclusion in this study. The data consisted of the TT-BD for PWIBDs and the potential variables influencing the TT-BD. Results: The mean age of the 414 PWIBDs was 48.9 years, and 120 of them were female (29.0%). The mean TT-BD was 8.5 days. The presence of spontaneous movements (SMs) and craniotomy significantly affected the TT-BD. The mean TT-BDs were 13.9 and 8.2 days in the PWIBDs with and without SMs, respectively, and 9.8 and 8.0 days in the PWIBDs with and without craniotomy, respectively. Conclusions The SMs in PWIBDs and a craniotomy performed immediately before starting the process of determining brain death seem to be related to lengthening the TT-BD.

Brain death is a clinical diagnosis that implies irreversible loss of function of the entire brain, including the brainstem and both hemispheres. It is not uncommon for reflex and spontaneous movements to occur in patients with impending brain death during the process of determining brain death. When physicians charged with judging brain death witness such movements during this period, unless they know how common these movements are and what they mean, it will be difficult for them to make an appropriate determination of brain death. Movements following brain death have been reported in previous studies of various types, including cohort studies and case series or reports. However, only a few studies have employed verified diagnostic tools and neurological examinations as a standard protocol when diagnosing brain death. According to previous reports, the frequency of these movements ranges from 19.2% to 75.0% of all brain death cases. These reports have also described which movements are commonly seen. However, it is difficult to determine conclusively where these movements originate, i.e., in the spinal cord or in the cerebral motor cortex, and how such information should be considered in determining brain death. Although limited information is available on the characteristics and pathophysiological mechanism of these movements, it will help physicians to diagnose brain death correctly if they obtain sufficient knowledge about them.
Brain Death ; Brain Stem ; Brain ; Cohort Studies ; Diagnosis ; Humans ; Motor Cortex ; Neurologic Examination ; Reflex ; Spinal Cord

BACKGROUND: Brain death is a clinical diagnosis that implies irreversible loss of function of the entire brain, including the brainstem and both hemispheres. Based on previous reports, it is not rare for reflex and spontaneous movements to occur in patients during the process of determining brain death. However, reports of the frequency and common types of these movements vary from study to study. Thus, we evaluated adult patients with impending brain death in Korea to determine the frequency and characteristics of reflex and spontaneous movements.METHODS: Brain dead patients who were admitted to 15 hospitals in the Yeongnam region (Southeast) of Korea were recruited prospectively from January 2013 to September 2016. All patients met the criteria for brain death as established by the Korea Medical Association. All body movements occurred during the process of diagnosing brain death and were assessed by physicians and trained organ transplant coordinators. The frequency and characteristics of these movements were identified and the demographic and clinical factors of impending brain dead patients with and without these movements were compared.RESULTS: A total of 436 patients who met the criteria for brain death were enrolled during the study period. Of these patients, 74 (17.0%) exhibited either reflex or spontaneous movements. Of this subset, 45 (60.8%) exhibited reflex movements only, 18 (24.3%) exhibited spontaneous movements only, and 11 (14.9%) exhibited both reflex and spontaneous movements. The most common reflex movements were the flexor/extensor plantar response and spinal myoclonus. Of the 74 patients, 52 (70.3%) exhibited one movement of the same pattern and 22 (29.7%) exhibited two or more different movement patterns. In addition, 45 (60.8%) exhibited these movements only on a limited area of the body with the leg being most common (n = 26, 57.8%). Patients with hypoxic brain damage and a higher systolic blood pressure exhibited significantly more reflex or spontaneous movements.CONCLUSION: Movements associated with brain dead patients are not rare and thus an awareness of these movements is important to brain death diagnosis. Physicians who perform brain death examinations should understand the frequency and characteristics of these movements to reduce delays in determining brain death.

BACKGROUND: Brain death is a clinical diagnosis that implies irreversible loss of function of the entire brain, including the brainstem and both hemispheres. Based on previous reports, it is not rare for reflex and spontaneous movements to occur in patients during the process of determining brain death. However, reports of the frequency and common types of these movements vary from study to study. Thus, we evaluated adult patients with impending brain death in Korea to determine the frequency and characteristics of reflex and spontaneous movements. METHODS: Brain dead patients who were admitted to 15 hospitals in the Yeongnam region (Southeast) of Korea were recruited prospectively from January 2013 to September 2016. All patients met the criteria for brain death as established by the Korea Medical Association. All body movements occurred during the process of diagnosing brain death and were assessed by physicians and trained organ transplant coordinators. The frequency and characteristics of these movements were identified and the demographic and clinical factors of impending brain dead patients with and without these movements were compared. RESULTS: A total of 436 patients who met the criteria for brain death were enrolled during the study period. Of these patients, 74 (17.0%) exhibited either reflex or spontaneous movements. Of this subset, 45 (60.8%) exhibited reflex movements only, 18 (24.3%) exhibited spontaneous movements only, and 11 (14.9%) exhibited both reflex and spontaneous movements. The most common reflex movements were the flexor/extensor plantar response and spinal myoclonus. Of the 74 patients, 52 (70.3%) exhibited one movement of the same pattern and 22 (29.7%) exhibited two or more different movement patterns. In addition, 45 (60.8%) exhibited these movements only on a limited area of the body with the leg being most common (n = 26, 57.8%). Patients with hypoxic brain damage and a higher systolic blood pressure exhibited significantly more reflex or spontaneous movements. CONCLUSION Movements associated with brain dead patients are not rare and thus an awareness of these movements is important to brain death diagnosis. Physicians who perform brain death examinations should understand the frequency and characteristics of these movements to reduce delays in determining brain death.