scholarly journals Pure Amorphagnosia without Tactile Object Agnosia

2017 ◽  
Vol 9 (1) ◽  
pp. 62-68
Author(s):  
Shinichirou Kubota ◽  
Mai Yamada ◽  
Hideyo Satoh ◽  
Akira Satoh ◽  
Mitsuhiro Tsujihata
Keyword(s):  
Cerebral Infarction ◽  
Frontal Cortex ◽  
Right Hemisphere ◽  
Brain Mri ◽  
Angular Gyrus ◽  
Supramarginal Gyrus ◽  
Left Hand ◽  
3 Dimensional ◽  
Real Objects ◽  
The Right

A 54-year-old female showed amorphagnosia without ahylognosia and tactile agnosia 40 days after the onset of right cerebral infarction. Her basic somatosensory functions were normal. The appreciation of substance qualities (hylognosia) was preserved, but the patient’s inability to recognize the size and shape (morphagnosia) was confined to 2- and 3-dimensional shapes (amorphagnosia) in the left hand. However, the patient’s ability to recognize real daily objects was well preserved. Brain MRI after admission showed ischemic lesions confined to the right pre- and postcentral gyri and the medial frontal cortex on DWI and FLAIR images. An analysis of SPECT images revealed that the most decreased areas were localized to the pre- and postcentral gyri, superior and inferior parietal lobules, supramarginal gyrus, and angular gyrus. Considering the previous reported cases, the responsible lesion for the impaired perception of hylognosia and morphagnosia may not necessarily be confined to the right hemisphere. To date, 5 reports (6 cases) of tactile agnosia have been published; 4 cases presented with both ahylognosia and amorphagnosia, while 1 presented with only amorphagnosia, and another showed amorphagnosia and mild ahylognosia. Our case is the first to present with only amorphagnosia without tactile agnosia. The mechanism for the well-preserved recognition of real objects may depend on the preserved hylognosia. Of note, there have been no reports showing only ahylognosia without amorphagnosia. Further studies are necessary to clarify whether or not patients with preserved hylognosia or morphagnosia retain the ability to perceive real objects.

scholarly journals Disentangling Mathematics from Executive Functions by Investigating Unique Functional Connectivity Patterns Predictive of Mathematics Ability

2019 ◽  
Vol 31 (4) ◽  
pp. 560-573 ◽  
Author(s):  
Kenny Skagerlund ◽  
Taylor Bolt ◽  
Jason S. Nomi ◽  
Mikael Skagenholt ◽  
Daniel Västfjäll ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Inferior Frontal Gyrus ◽  
Premotor Cortex ◽  
Mathematical Ability ◽  
Angular Gyrus ◽  
Intraparietal Sulcus ◽  
Supramarginal Gyrus ◽  
Connectivity Patterns ◽  
The Right

What are the underlying neurocognitive mechanisms that give rise to mathematical competence? This study investigated the relationship between tests of mathematical ability completed outside the scanner and resting-state functional connectivity (FC) of cytoarchitectonically defined subdivisions of the parietal cortex in adults. These parietal areas are also involved in executive functions (EFs). Therefore, it remains unclear whether there are unique networks for mathematical processing. We investigate the neural networks for mathematical cognition and three measures of EF using resting-state fMRI data collected from 51 healthy adults. Using 10 ROIs in seed to whole-brain voxel-wise analyses, the results showed that arithmetical ability was correlated with FC between the right anterior intraparietal sulcus (hIP1) and the left supramarginal gyrus and between the right posterior intraparietal sulcus (hIP3) and the left middle frontal gyrus and the right premotor cortex. The connection between the posterior portion of the left angular gyrus and the left inferior frontal gyrus was also correlated with mathematical ability. Covariates of EF eliminated connectivity patterns with nodes in inferior frontal gyrus, angular gyrus, and middle frontal gyrus, suggesting neural overlap. Controlling for EF, we found unique connections correlated with mathematical ability between the right hIP1 and the left supramarginal gyrus and between hIP3 bilaterally to premotor cortex bilaterally. This is partly in line with the “mapping hypothesis” of numerical cognition in which the right intraparietal sulcus subserves nonsymbolic number processing and connects to the left parietal cortex, responsible for calculation procedures. We show that FC within this circuitry is a significant predictor of math ability in adulthood.

Verbal and design fluency in patients with frontal lobe lesions

2001 ◽  
Vol 7 (5) ◽  
pp. 586-596 ◽  
Author(s):  
JULIANA V. BALDO ◽  
ARTHUR P. SHIMAMURA ◽  
DEAN C. DELIS ◽  
JOEL KRAMER ◽  
EDITH KAPLAN
Keyword(s):  
Frontal Cortex ◽  
Frontal Lobe ◽  
Verbal Fluency ◽  
Right Hemisphere ◽  
Verbal Fluency Task ◽  
Frontal Lobe Lesions ◽  
Design Fluency ◽  
The Right ◽  
Frontal Lesions ◽  
Fluency Task

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes. (JINS, 2001, 7, 586–596.)

Dominance of the Right Hemisphere and Role of Area 2 in Human Kinesthesia

2005 ◽  
Vol 93 (2) ◽  
pp. 1020-1034 ◽  
Author(s):  
Eiichi Naito ◽  
Per E. Roland ◽  
Christian Grefkes ◽  
H. J. Choi ◽  
Simon Eickhoff ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Anterior Part ◽  
Premotor Cortex ◽  
Superior Temporal Gyrus ◽  
Lateral Part ◽  
Left Hand ◽  
Hemisphere Dominance ◽  
The Right ◽  
Processus Styloideus ◽  
Motor Areas

We have previously shown that motor areas are engaged when subjects experience illusory limb movements elicited by tendon vibration. However, traditionally cytoarchitectonic area 2 is held responsible for kinesthesia. Here we use functional magnetic resonance imaging and cytoarchitectural mapping to examine whether area 2 is engaged in kinesthesia, whether it is engaged bilaterally because area 2 in non-human primates has strong callosal connections, which other areas are active members of the network for kinesthesia, and if there is a dominance for the right hemisphere in kinesthesia as has been suggested. Ten right-handed blindfolded healthy subjects participated. The tendon of the extensor carpi ulnaris muscles of the right or left hand was vibrated at 80 Hz, which elicited illusory palmar flexion in an immobile hand (illusion). As control we applied identical stimuli to the skin over the processus styloideus ulnae, which did not elicit any illusions (vibration). We found robust activations in cortical motor areas [areas 4a, 4p, 6; dorsal premotor cortex (PMD) and bilateral supplementary motor area (SMA)] and ipsilateral cerebellum during kinesthetic illusions (illusion-vibration). The illusions also activated contralateral area 2 and right area 2 was active in common irrespective of illusions of right or left hand. Right areas 44, 45, anterior part of intraparietal region (IP1) and caudo-lateral part of parietal opercular region (OP1), cortex rostral to PMD, anterior insula and superior temporal gyrus were also activated in common during illusions of right or left hand. These right-sided areas were significantly more activated than the corresponding areas in the left hemisphere. The present data, together with our previous results, suggest that human kinesthesia is associated with a network of active brain areas that consists of motor areas, cerebellum, and the right fronto-parietal areas including high-order somatosensory areas. Furthermore, our results provide evidence for a right hemisphere dominance for perception of limb movement.

Primary cerebellar histiocytic sarcoma in a 17-month-old girl

2012 ◽  
Vol 10 (2) ◽  
pp. 126-129 ◽  
Author(s):  
Kiyoshi Gomi ◽  
Mio Tanaka ◽  
Mariko Yoshida ◽  
Susumu Ito ◽  
Masaki Sonoda ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Brain Mri ◽  
Histiocytic Sarcoma ◽  
Cerebellar Tumor ◽  
Pediatric Age Group ◽  
Old Japanese ◽  
History Of ◽  
Dural Attachment ◽  
The Right ◽  
Aggressive Clinical Course

The authors report on a case of histiocytic sarcoma (HS) in a pediatric patient presenting with a solitary tumor in the cerebellum, with the aim of providing insight into primary HS in the CNS, which is especially rare. A 17-month-old Japanese girl presented with a 2-week history of progressive gait disturbance. Brain MRI revealed a 4.7 × 4.3 × 4.3–cm well-demarcated solitary mass in the right hemisphere of the cerebellum, initially suggestive of medulloblastoma, ependymoma, or anaplastic astrocytoma. On intraoperative inspection the cerebellar tumor showed intensive dural attachment and was subtotally removed. Histological and immunohistochemical findings were consistent with HS. The patient subsequently received chemotherapy, and her preoperative neurological symptoms improved. Primary HS in the CNS usually demonstrates an aggressive clinical course and is currently considered to have a poor prognosis. The possibility of this rare tumor should be included in the differential diagnosis of localized cerebellar tumors in the pediatric age group.

Spatiotemporal Human Brain Activities on Recalling Names of Body Parts

2013 ◽  
Vol 17 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Takahiro Yamanoi ◽  
◽  
Yoshinori Tanaka ◽  
Mika Otsuki ◽  
Shin-ichi Ohnishi ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Event Related Potentials ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Dipole Source ◽  
Body Parts ◽  
Current Dipole ◽  
Middle Temporal ◽  
Related Potentials ◽  
The Right

The authors measure electroencephalograms (EEGs) from a subject looking at line drawings of body parts and recalling their names silently. The equivalent current dipole source localization (ECDL) method is applied to the event related potentials (ERPs): summed EEGs. As the dominant language area of the subject is considered to be in the right hemisphere in the previous research study, ECDs are localized to the right middle temporal gyrus: the angular gyrus. Then ECDs are localized to the right fusiform gyrus, the right middle temporal pole (TEP), and the right inferior temporal white matter (TWM). ECDs are located in the ventral pathway. The areas are related to the integrated process of visual recognition of pictures and the recalling of words. Some of these areas are also related to image recognition and word generation.

Three-dimensional neglect phenomena following right anterior choroidal artery infarction

1999 ◽  
Vol 5 (6) ◽  
pp. 567-571 ◽  
Author(s):  
ADRIANA KORI ◽  
DAVID S. GELDMACHER
Keyword(s):  
Right Hemisphere ◽  
Three Dimensional ◽  
Spatial Processing ◽  
Anterior Choroidal Artery ◽  
3 Dimensional ◽  
Spatial Dimensions ◽  
Anterior Choroidal ◽  
True Center ◽  
The Right ◽  
Choroidal Artery

Neglect in the horizontal and vertical axes of space has been observed after acute right anterior choroidal artery (AChA) lesions. How spatial processing is affected in the radial axis during the acute period following infarction in this region is unknown. We report the case of a 69-year-old man with acute left hemineglect and deficits in 3-dimensional spatial processing following right AChA infarction. His line bisections in 4 spatial conditions, oriented in the 3 primary axes of space, were compared with 6 control participants. The patient's bisections were different from true center and from control performance in all axes. His bisections were to the right, below, and distal to the arithmetic midpoint. This patient's bisection errors show a 3-dimensional neglect pattern following right AChA infarction, supporting the view that processing of all 3 spatial dimensions may be simultaneously disturbed following unilateral right hemisphere lesions. (JINS, 1999, 5, 567–571.)

Fingertip Number Writing Errors in Hospitalized Non-Neurologic Patients

1983 ◽  
Vol 56 (2) ◽  
pp. 551-554 ◽  
Author(s):  
J. Preston Harley ◽  
Jordan Grafman
Keyword(s):  
Right Hemisphere ◽  
Adult Males ◽  
Left Hand ◽  
Neurological Signs ◽  
The Right ◽  
Writing Errors

Accuracy of perception of 4 numbers tactilely presented to fingers of both hands by 56 right-handed adult males who were hospitalized but showed no positive neurological signs was greater for the left hand. Middle fingers were superior; number 4 was most easily identified. Findings suggest superior capacity of the right hemisphere for this task.

Influence of Spatial Mapping on Manual Aiming Asymmetries

1998 ◽  
Vol 86 (3) ◽  
pp. 967-975 ◽  
Author(s):  
Brian K. V. Maraj ◽  
Digby Elliott ◽  
James Lyons ◽  
Eric A. Roy ◽  
Tamara Winchester
Keyword(s):  
Right Hemisphere ◽  
Movement Time ◽  
Left Hand ◽  
Stimulus Response ◽  
Right Hand ◽  
Movement Error ◽  
Computer Mouse ◽  
Spatial Translation ◽  
Different Diameters ◽  
The Right

Two experiments were conducted to examine manual asymmetries in a one-dimensional aiming task. In Exp. 1, 10 right-handed adults slid a computer mouse 13 cm on a graphics tablet with both the right and left hands to targets of 3 different diameters. Under these conditions, the movement time for the right hand was significantly faster as expected. In Exp. 2, subjects performed similar movements to move a cursor 13 cm on a computer monitor. Thus the study was identical except the stimulus-response mapping was indirect. In this situation, there were no significant differences for either movement time or movement error between hands despite these performance measures indicating that target aiming was more difficult in Exp. 2. Because increases in task difficulty generally result in a greater advantage for the right hand, as indicated by Todor & Smiley, 1985, the present studies suggest that superiority of the right hand in aiming tasks may be diminished when spatial translation is required. Perhaps the spatial translation requires greater involvement of the right hemisphere, a process associated with manual advantage for the left hand, previously suggested by Roy and MacKenzie.

scholarly journals Drawing with the Non-dominant Hand: Implications for the Study of Construction

1998 ◽  
Vol 25 (4) ◽  
pp. 306-309 ◽  
Author(s):  
Sherma Zacharias ◽  
Andrew Kirk
Keyword(s):  
Neurological Disease ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Elderly Subjects ◽  
Dominant Hand ◽  
Left Hand ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hand

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.

scholarly journals Motor Extinction in Distinct Reference Frames: A Double Dissociation

2013 ◽  
Vol 26 (1-2) ◽  
pp. 111-119 ◽  
Author(s):  
Jennifer Heidler-Gary ◽  
Mikolaj Pawlak ◽  
Edward H. Herskovits ◽  
Melissa Newhart ◽  
Cameron Davis ◽  
...  
Keyword(s):  
White Matter ◽  
Reference Frames ◽  
Right Hemisphere ◽  
Hand Movements ◽  
Lesion Site ◽  
Left Hand ◽  
Double Dissociation ◽  
Ischemic Tissue ◽  
The Right ◽  
Right Hemisphere Stroke

Objective:Test the hypothesis that right hemisphere stroke can cause extinction of left hand movements or movements of either hand held in left space, when both are used simultaneously, possibly depending on lesion site.Methods:93 non-hemiplegic patients with acute right hemisphere stroke were tested for motor extinction by pressing a counter rapidly for one minute with the right hand, left hand, or both simultaneously with their hands held at their sides, or crossed over midline.Results:We identified two distinct types of motor extinction in separate patients; 20 patients extinguished left hand movements held in left or right space (left canonical body extinction); the most significantly associated voxel cluster of ischemic tissue was in the right temporal white matter. Seven patients extinguished either hand held in left space (left space extinction), and the most significantly associated voxel cluster of ischemic tissue was in right parietal white matter.Conclusions:There was a double dissociation between left canonical body extinction and left space motor extinction. Left canonical body extinction seems to be associated with more dorsal (parietal) ischemia, and left canonical body extinction seems to be associated with more ventral (temporal) ischemia.

Sign in / Sign up

Export Citation Format

Share Document