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Introduction to botulinum toxin
Published in Michael Parker, Charlie James, Fundamentals for Cosmetic Practice, 2022
All conscious movements begin in a specialised area of the brain known as the precentral gyrus (Figure 8.3), which is colloquially known as the motor strip. The precentral gyrus is found in the posterior frontal lobe and is separated from the primary somato-sensory cortex (the postcentral gyrus) by the central sulcus.
Anatomy of the head and neck
Published in Helen Whitwell, Christopher Milroy, Daniel du Plessis, Forensic Neuropathology, 2021
Each cerebral hemisphere is subdivided into regions, or lobes, named after the overlying cranial bones. On each hemisphere, the deep groove of the central sulcus divides the anterior frontal lobe from the posterior parietal lobe. The lateral surface of the frontal lobe comprises the precentral gyrus with the precentral sulcus in front. The inferior surface is marked by orbital gyri and is in direct contact with the forward extending olfactory tract and bulb.
Central nervous system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Certain areas are identified with specific brain functions. The pre-central gyrus is known as the motor cortex and is the origin of all voluntary movements. The post-central gyrus is known as the sensory cortex and receives and appreciates all general sensations. Other important areas include the auditory area, which receives impulses from the auditory nerve and is situated in the cortex of the temporal lobe immediately below the lateral sulcus; the visual area, situated in the cortex of the occipital lobe and receives impulses via the optic chiasm; and the motor speech area (Broca’s area), which initiates tongue movements and is situated in the cortex of the frontal lobe just above the anterior end of the lateral sulcus. The sensory speech area that interprets the written and spoken word is situated in the lower part of the parietal cortex.
Abnormal functional connectivity of brain regions associated with fear network model in panic disorder
Published in The World Journal of Biological Psychiatry, 2022
Shuangyi Zhou, Shanshan Su, Ang Hong, Chen Yang, Qiang Liu, Wei Feng, Zhen Wang
The precentral gyrus has been found abnormal activities in PD in previous studies (Sim et al. 2010; Kang et al. 2012; Lai and Wu 2013; Seo et al. 2014; Shang et al. 2014; Kennis et al. 2015). Our study also found it has increased rsFC with the thalamus. This finding suggests that we should pay attention to the role of the motor region, such as the precentral gyrus in the advanced FNM. The strengthened rsFC between the precentral gyrus and the thalamus indicated the precentral gyrus is related to the motor symptoms in panic attacks, such as fright, escape behaviour, and fear to lose control (Lai and Wu 2016). In conclusion, the precentral gyrus may have negative feedback for sensory filtering and integration. It can also explain why PD patients show more somatic anxiety than the other anxiety patients.
Grey matter volume abnormalities in the first depressive episode of medication-naïve adult individuals: a systematic review of voxel based morphometric studies
Published in International Journal of Psychiatry in Clinical Practice, 2021
Meysam Amidfar, João Quevedo, Gislaine Z. Réus, Yong-Ku Kim
First-episode drug-naïve MDD patients also showed reduced grey matter volume in the left precentral gyrus, compared to controls (Zhang et al. 2012). Although the precentral gyrus mainly consists of the primary motor cortex including the premotor cortex and the supplementary motor area that traditionally role playing in voluntary movement, however VBM studies reported significantly smaller volume of precentral gyrus in subjects with subthreshold depression (Taki et al. 2005) and in individuals with early or late at-risk mental state (Koutsouleris et al. 2009). Interestingly, brain imaging studies have suggested the precentral gyrus as a region involved in both emotional and cognitive processes (Frijda 2010; Coombes et al. 2012). The smaller regional GMV of the right pre-supplementary motor area (pre-SMA) was found in drug-naïve first-episode MDD patients that suggest the GMV reduction of the pre-SMA as a biomarker for identifying depression at an early stage, especially in the first year after onset (Cheng et al. 2010).
Deficits underlying handgrip performance in mildly affected chronic stroke persons
Published in Topics in Stroke Rehabilitation, 2021
Esther Prados-Román, Irene Cabrera-Martos, Laura López-López, Janet Rodríguez-Torres, Irene Torres-Sánchez, Araceli Ortiz-Rubio, Marie Carmen Valenza
Jung et al.4 demonstrated that persons with weakness of the ipsilesional upper limb maximally recovered within 1-month poststroke but remained impaired in comparison with controls. Persistent impaired reaction time within the first year poststroke has been shown, indicating that ipsilesional upper limbs deficits might not be a temporary event.39,40 It has been shown that both the precision- and power-grip tasks activated the primary sensorimotor cortex contralateral to the grasping hand. The activations extended into the dorsal premotor cortex and the postcentral sulcus. Furthermore, the ventral premotor cortex showed bilateral activation with peaks of activity in the inferior part of the precentral gyrus.41 Among common assumptions motor deficits caused by disruption of ipsilesional projections of the corticospinal tract42 and changes in ipsilesional motor performance after nonaffected primary motor cortex disinhibition43 are included. However, little is known about the time course evolution of ipsilesional handgrip assessment, and even less about its implications for rehabilitation.40,44 Previous studies45,46 have reported difficulties in most clinical tests to detect fine changes in motor performance, specially the subtle ipsilesional motor deficits. Our study found significant differences on grip and pinch resistance to fatigue in the ipsilesional hand in comparison with controls. Moreover, significant differences were found on flexor digitorum superficialis muscle fatigue during a sustained handgrip contraction.