Crossed aphasia refers to a combination of aphasia and right hemiparesis in a left handed person or left hemiparesis and aphasia in a dextral. While crossed aphasia is not infrequent at all among left-handers, it remains an extremely rare event in dextrals. Its incidence is probably about 0.4% after right hemispheric lesions and prevalence is about 1% among right-handed aphasics. The neurobiological mechanisms of this phenomenon are unknown, and the neuropsychological correlations are only incompletely understood. We report a case of crossed aphasia in a 61-year-old right-handed woman who presented with sudden, severe global aphasia and left hemiplegia without any personal or family history of left-handedness. Brain MR image clearly showed a right hemispheric infarction in the territory of the right middle cerebral artery and brain SPECT also displayed reduction of regional cerebral blood flow in the right hemisphere sparing the left hemisphere. In this patient, cerebral dominance for speechseems to lay in the right hemisphere, while dominance for limb praxis seemsto lay in the left as the patient did not develop right limb apraxia. This case provides evidence that cerebral dominance for speech and handedness in dextrals can be dissociated. It also suggests that crossed aphasia in a dextral may be severe and persisting.
Aphasia* ; Apraxias ; Brain ; Dominance, Cerebral ; Extremities ; Female ; Functional Laterality ; Hand ; Hemiplegia ; Humans ; Incidence ; Infarction ; Middle Aged ; Middle Cerebral Artery ; Paresis ; Prevalence ; Tomography, Emission-Computed, Single-Photon

OBJECTIVE: Determining language lateralization is important for the presurgical evaluation of patients with medically intractable epilepsy. The Wada test has been the gold standard for lateralization of language dominance before epilepsy surgery. However, it is an invasive test with risk, and have some limitations. METHODS: We compared the volumetric analysis with Wada test, and studied the clinical potential of volumetric analysis to assess language laterality in large surgical candidates with temporal lobe epilepsy (TLE). To examine the efficacy of volumetric analysis to determine language lateralization during presurgical evaluation, we compared the volumetric analysis of the bilateral planum temporale with the results of Wada test in 59 patients with chronic intractable TLE (rTLE, n=32; lTLE, n=27) who underwent epilepsy surgery. We measured the gray matter volumes of planum temporale (PT) of each patients using the VoxelPlus2 program (Mevisys, Daejeon, Korea). RESULTS: Overall congruence of the volumetric analysis with the Wada test was 97.75% in rTLE patients and 81.5% in lTLE patients. There were more significant leftward asymmetry of the PT in rTLE patients than lTLE patients. In lTLE patients, relatively high proportion (37%) of the patients showed bilateral or right hemispheric language dominance. CONCLUSION: These results provide evidence that the volumetric analysis of the PT could be used as an alternatives in language lateralization. Also, the results of the Wada test suggested that there was considerable plasticity of language representation in the brains of patients with intractable TLE and it was associated with an earlier age of brain injury.
Brain ; Brain Injuries ; Dominance, Cerebral ; Epilepsy ; Epilepsy, Temporal Lobe ; Humans ; Plastics ; Temazepam ; Temporal Lobe

OBJECTIVE: To develop and standardize the Limb and Oral Apraxia Test (LOAT) for Korean patients and investigate its reliability, validity, and clinical usefulness for patients with stroke. METHODS: We developed the LOAT according to a cognitive neuropsychological model of limb and oral praxis. The test included meaningless, intransitive, transitive, and oral praxis composed of 72 items (56 items on limb praxis and 16 items on oral praxis; maximum score 216). We standardized the LOAT in a nationwide sample of 324 healthy adults. Intra-rater and inter-rater reliability and concurrent validity tests were performed in patients with stroke. We prospectively applied the LOAT in 80 patients and analyzed the incidence of apraxia. We also compared the clinical characteristics between the apraxia and non-apraxia groups. RESULTS: The internal consistency was high (Cronbach’s alpha=0.952). The inter-rater and intra-rater reliability and concurrent validity were also high (r=0.924–0.992, 0.961–0.999, and 0.830, respectively; p<0.001). The mean total, limb, and oral scores were not significantly different according to age and education (p>0.05). Among the 80 patients with stroke, 19 (23.8%) had limb apraxia and 21 (26.3%) had oral apraxia. Left hemispheric lesions and aphasia were significantly more frequently observed in the limb/oral apraxia group than in the non-apraxia group (p<0.001). CONCLUSION: The LOAT is a newly developed comprehensive test for limb and oral apraxia for Korean patients with stroke. It has high internal consistency, reliability, and validity and is a useful apraxia test for patients with stroke.
Adult ; Aphasia ; Apraxias ; Dominance, Cerebral ; Education ; Extremities ; Humans ; Incidence ; Prospective Studies ; Psychometrics ; Reproducibility of Results ; Stroke

Animals ; Brain Mapping ; Dominance, Cerebral ; Magnetic Resonance Imaging ; Parietal Lobe ; Primates

Blood flow velocity changes induced by the focal brain activation can be assessed by using Transcranial Doppler sonography (TCD). To explore the hemispheric dominant hemodynamic effect by performing calculation, we applied TCD technique to detect cerebral blood velocity asymmetry. METHODS Twenty healthy right-handed subjects were tested. We measured mean flow velocities (MFV) in the middle and posterior cerebral arteries (MCA, PCA). Photic stimulation was given separately as a control task for calculation. RESULTS While the photic stimulation increased the blood velocity only in PCAs, performing calculation increased the velocity in MCAs. Right-left difference was noted by performing calculation with greater increase in left MCA (right: 8.8 %; left: 21.2 %). CONCLUSION Application of TCD enabled us to measure the hemodynamic changes supporting the left hemispheric dominance of calculation task. Futhermore, increase in non-dominant right hemisphere suggests the functional interaction of cerebral activity.
Blood Flow Velocity* ; Brain ; Dominance, Cerebral ; Hemodynamics ; Passive Cutaneous Anaphylaxis ; Photic Stimulation ; Posterior Cerebral Artery ; Ultrasonography, Doppler, Transcranial

Central nervous system is often involved by herpes zoster but it is very rarely seen that contralateral hemiparesis or hemiplegia developed after herpes zoster ophthalmicus. We report a case of herpes zoster ophthalmicus followed by the delayed contralateral hemiparesis. A 33-year-old man developed acute cerebral infarction and resultant right hemiparesis 44 days after herpes zoster ophthalmicus in the left side. Brain CT disclosed hypodense area in the left basal ganglia. Cerebral angiography revealed segmental narrowing of M1 portion of the right middle cerebral artery.
Adult ; Cerebral Angiography ; Cerebral Arteries/pathology ; Cerebral Infarction/*etiology/radiography ; Dominance, Cerebral ; Hemiplegia/*etiology ; Herpes Zoster Ophthalmicus/*complications ; Humans ; Male ; Tomography, X-Ray Computed ; Vasculitis/etiology

No abstract available.
Functional Laterality*

Our survival and wellness require a balance between optimism and pessimism. Undue pessimism makes life miserable; however, excessive optimism can lead to dangerously risky behaviors. A review and synthesis of the literature on the neurophysiology subserving these two worldviews suggests that optimism and pessimism are differentially associated with the two cerebral hemispheres. High self-esteem, a cheerful attitude that tends to look at the positive aspects of a given situation, as well as an optimistic belief in a bright future are associated with physiological activity in the left-hemisphere (LH). In contrast, a gloomy viewpoint, an inclination to focus on the negative part and exaggerate its significance, low self-esteem as well as a pessimistic view on what the future holds are interlinked with neurophysiological processes in the right-hemisphere (RH). This hemispheric asymmetry in mediating optimistic and pessimistic outlooks is rooted in several biological and functional differences between the two hemispheres. The RH mediation of a watchful and inhibitive mode weaves a sense of insecurity that generates and supports pessimistic thought patterns. Conversely, the LH mediation of an active mode and the positive feedback it receives through its motor dexterity breed a sense of confidence in one's ability to manage life's challenges, and optimism about the future.
Cerebrum ; Depression ; Functional Laterality ; Negotiating ; Neurophysiology

BACKGROUNDS: Gamma band oscillatory activity is considered to be related to congnitive functions and illustrates that the concept of event-related oscillations bridges the gap between single neurons and neural assemblies. An event-related gamma oscillation is the time - locked responses of specific frequency, and can be identified by computing the amplitude frequency characteristics of the averaged event-related potentials(ERPs) after stimulation. OBJECTIVES: We purposed to present experimental paradigm to investigate @-band oscillation activities from the recording of ERPs by using auditory oddball paradigm and investigate the difference of @-band activity between schizophrenia and normal controls. METHODS: The ERPs resulting from auditory stimuli with oddball paradigm in a group of schizophrenics(n=11) and also a group of age-, sex- and handedness matched normal controls, were recorded by 128 channel EEG. The @-band oscillatory activities were calculated by using time-frequency wavelet decomposition of the signal between 20 and 80Hz. The @-band oscillatory activities of both groups were compared by t-test. RESULTS: The @-band oscillatory of the leads Fz,Gz and Pz of both groups were represented well in the time - frequency maps. Significant increases of the @-band activity in normal controls compared with schizophrenics were observed around 160 msec. 350msec. and 800 msec after stimulation. CONCLUSIONS: Our results suggested that the increment in @-band oscillatory activity during cognitive operations and decreased @-band activity in schizophrenics may be associated with the cognitive dysfunctions and the pathophyiology of the schizophrenia.
Electroencephalography ; Evoked Potentials* ; Functional Laterality ; Neurons ; Schizophrenia

OBJECTIVE: Schneiderian first-rank symptoms (FRS) and abnormal EEG gamma activity in schizophrenia have been reported independently to have a neurodevelopmental basis. We aimed to investigate spontaneous gamma power in two groups of first episode schizophrenia patients (those who experience FRS and those who do not). METHODS: A comparative hospital based study having 37neuroleptic naive male patients with schizophrenia divided into two groups-FRS(+) and FRS(-) groups based on the presence of FRS. Thirty age, sex, education and handedness matched individuals served as controls (N). All participants underwent a 192-channel resting Electroencephalography (EEG) recording. Gamma spectral power was calculated for low- (30-50 Hz) and high-gamma 1 & 2 (51-70 and 71-100 Hz) bands. Spectral power was compared between three groups using MANOVA and supplementary one-way ANOVA with Bonferroni test controlling for multiple comparisons. Linear regression was used to identifying predictor variables for FRS. Pearson correlation coefficient was computed between spectral power parameters and various clinical variables. RESULTS: Significantly higher high gamma band-1 power was observed over right frontal (p<0.05), parietal (p<0.05) and temporal (p<0.05) regions in FRS(+) than FRS(-) group and normal controls. Right parietal high gamma-1 power and paranoid cluster on PANSS significantly predicted number of FRS in total schizophrenia patients; paranoid cluster on PANSS showed significant correlation with number of FRS in FRS(+) group. CONCLUSION: Findings of our study add to the evidence that areas contained within the hetero modal association cortex are associated with FRS. The study findings also strengthen the neurodevelopmental basis of FRS in schizophrenia.
Education ; Electroencephalography* ; Functional Laterality ; Humans ; Linear Models ; Male ; Rabeprazole ; Schizophrenia*