Gerstmann Syndrome (Dysgraphia, Dyscalculia, Finger Agnosia, and Left-Right Disorientation)
Alexander R. Toftness in Incredible Consequences of Brain Injury, 2023
Damage to a part of the brain called the angular gyrus, located near where the parietal and temporal lobes meet, appears to be enough to produce this syndrome. However, there are reports of people developing some of the symptoms even with brain damage in different areas (Bhattacharyya et al., 2014). For example, dyscalculia can be a symptom of damage to many different brain locations, including frontal, temporal, parietal, and subcortical structures, although the angular gyrus is probably the most frequently implicated (e.g., Grafman et al., 1982; Willmes, 2008). Importantly, Gerstmann syndrome is commonly associated with damage to the dominant hemisphere of a person's brain (Tucha et al., 1997). In right-handed people, the left side of the brain is usually dominant, and because most people are right-handed, Gerstmann syndrome is usually associated with damage to the left half of the brain. Therefore, Gerstmann syndrome is most frequently associated with left-sided damage of the angular gyrus… but there are exceptions to all of this (Lebrun, 2005). In fact, there are a lot of exceptions to the guidelines of this syndrome, which brings us to an important question.
Signs and Symptoms in Psychiatry
Mohamed Ahmed Abd El-Hay in Essentials of Psychiatric Assessment, 2018
Ideational apraxia: the inability to perform an organized motor sequence, although the individual components can be performed separately. It is possibly due to fear about how to carry out a movement, but once the patient has been cued he/she produces the correct response. It could be tested by asking the patient to show how he/she folds a letter, places it in an envelope, and then seals and stamps the envelope; lighting a candle with matches; or making a cup of coffee. To the observer, the patient gives the appearance of being naïve or unfamiliar with the sequence of activities that should occur. These patients fail to use everyday objects correctly. Ideational apraxia affects the limbs on both sides. It results from lesions in the region of the left angular gyrus.
Neurological Examination
Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner in The Integrated Nervous System, 2017
The fibers ascend the spinal cord and synapse in the lowermost medulla in the posterior column nuclei. The fibers of the second-order neurons cross and form a new pathway, the medial lemniscus, which ascends through the brainstem, terminating in the ventral posterolateral (VPL) nucleus of the thalamus; from here, fibers are distributed to the postcentral gyrus, the primary somatosensory cortex. (The details of this pathway are also discussed in Chapter 5.) This gyrus of the brain has different portions dedicated to each part of the body, called the sensory homunculus (similar to the motor homunculus; see Figure 4.2). Cortical processing in this gyrus allows for the localization of the stimulus.
Twelve tips for teaching neuroanatomy, from the medical students’ perspective
Published in Medical Teacher, 2023
Sanskrithi Sravanam, Chloë Jacklin, Eoghan McNelis, Kwan Wai Fung, Lucy Xu
Facing the sheer volume of neuroanatomy, we recommend that students obtain a strong grasp of the basic structures and conceptual framework before attempting the intricacies; students can then continue to build on their knowledge and confidence as they progress through the course. By omitting the complicated details initially, students seem to retain and recall core concepts more readily (Chang and An Moln 2019). Start with the key terms for describing the anatomical axes of the brain, i.e., dorsal/ventral, cranial/caudal, as these are fundamental for learning anatomy in 3 dimensions. Following this, teach the names of the lobes and their major functions to introduce the concept of cortical localisation. Naming the main sulci and gyri will aid the process of distinguishing the lobes of the brain. It is worth pointing out the stand-out features of the cerebellum at this point too, i.e., the hemispheres and the vermis.
Resting state functional brain imaging in obsessive-compulsive disorder across genders
Published in The World Journal of Biological Psychiatry, 2022
Yinzhu Ma, Qing Zhao, Tingting Xu, Pei Wang, Qiumeng Gu, Zhen Wang
The decreased FC between the right parahippocampal gyrus and bilateral fusiform gyrus in fOCD patients and HCs was negatively correlated with symptom severity of OCD, depression, and anxiety, while no similar correlation was found between mOCD patients and HCs. The fusiform gyrus is involved in the processing of high-order visual information, particularly related to faces, bodies, and stimuli characterised by high spatial frequencies (Palejwala et al. 2020). This further explains why fOCD patients tend to have significantly higher depression and anxiety compared to that of mOCD patients (Mathes et al. 2019). Deng et al. (2019) found that patients with OCD showed lower voxel-mirrored homotopic connectivity than HCs did in the fusiform gyrus, which supports our results. We hypothesise that decreased FC between the right parahippocampal gyrus and bilateral fusiform gyrus may underlie inhibitory impairment, resulting in excessive repetitive and worsened mood.
Brain activity and connectivity changes in response to glucose ingestion
Published in Nutritional Neuroscience, 2020
A. M. van Opstal, A. Hafkemeijer, A. A. van den Berg-Huysmans, M. Hoeksma, C. Blonk, H. Pijl, S. A. R. B. Rombouts, J. van der Grond
When investigating changes in brain connectivity, both with network analysis and Eigenvector centrality mapping, our data show that on both the voxel-wise and network level connectivity is generally increased after ingestion of plain water. Regions in which increased level and quality of voxel-wise connectivity was found were largely overlapping with functional networks that showed increased connectivity after drinking plain water. The transverse temporal gyrus is a part of the salience network,13 the precuneus and cingulate gyrus are part of the default mode network and the post-central gyrus falls within the sensory-motor functional network.13 The salience network, which also includes the insular and anterior cingulate cortex,22 is generally considered to be involved in emotional arousal, reward sensitivity, and decision-making.31 Connectivity changes in this network after plain water ingestion could therefore indicate an increased or continued energy and reward seeking. Indeed, several studies have shown an increased connectivity in the salience network in obesity that was linked to aberrant reward processing and overconsumption of energy.32,33 In general, ingestion of water after an overnight fast results in an increased BOLD signal and increased functional connectivity on both a voxel-wise and network level. It seems that where glucose decreases brain activity after an overnight fast, ingestion of plain water enhances brain activity, possibly associated with increased or continued reward and energy seeking.