Lesion localization
Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, Praveen V. Mummaneni in Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals, 2017
Discussion: The brainstem is the part of the brain continuous with the spinal cord and comprising the medulla oblongata, pons, and midbrain. It is involved in many automatic functions, such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing. Ten of the twelve cranial nerves originate in the brainstem (Slazinski and Littlejohns, 2004; Goldberg, 2010). Therefore, lesions affecting the brainstem commonly present with multiple cranial nerve deficits. In this case, the lower cranial nerves are affected because of their position to the medulla. The history reveals rapid progression of symptoms suggesting an aggressive lesion. Because the patient was emergently intubated, the examiner cannot assess the quality of his voice, but the history reveals a change, which can be reflective of glossopharyngeal, vagal, and hypoglossal nerve dysfunction. Swallow and gag have also been compromised. These could also reflect vagus nerve dysfunction. The sinus tachycardia could have been related to respiratory distress or direct involvement of vagus nerve dysfunction. The inability to lift his head from the pillow suggests spinal accessory nerve involvement. The tongue position and strength cannot properly be examined, but the history of dysarthric speech suggests hypoglossal nerve compromise (Slazinski and Littlejohns, 2004; Hobdell et al., 2004).
Brainstem and Cardiovascular Regulation
David Robertson, Italo Biaggioni in Disorders of the Autonomic Nervous System, 2019
Central control of the cardiovascular system is complex and still not well understood. The central nervous system (CNS) receives sensory information from many sources and sends out appropriate regulatory signals to several effector organs. It has been suggested that disturbances of these regulatory mechanisms may be involved in chronic elevation in systemic arterial pressure (Reis, 1981). For instance, abnormalities in central autonomic control may occur early in the course of borderline hypertension, and then over a period of years, through a sequence of secondary changes, lead to essential hypertension (Reis, 1981). Whether central autonomic control plays a role in borderline or essential hypertension is still unknown. Indeed, the neuronal circuitry in the brain is so complex that we still do not know the precise mechanisms of the depressor effect of some of the most commonly employed antihypertensive drugs, such as α-methyldopa and clonidine. But the more we understand about central cardiovascular regulatory mechanisms, the more we can assess its role in cardiovascular disease, and the more rationally we can approach new drug development. The aim of this chapter is to introduce key features of the brainstem neural cardiovascular control system.
Nervous system
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
The brain comprises three main regions or areas: the brainstem, the cerebellum and the cerebrum (Figure 12.7). In the previous chapters, we have discussed some of the actions of the brainstem, particularly in relation to the cardiovascular and respiratory centres. However, it is useful to recap some of this information here and take a further look at the different areas in context. We noted at the beginning of this chapter that the brainstem is attached to the spinal cord just above the level of C1 through the foramen magnum. Consequently, it is the lowest and the most primitive part of the brain and provides a common pathway for motor and sensory nerve impulses travelling to and from the spinal cord. It also coordinates many of the body’s autonomic responses necessary for homeostasis and life support in general. The brainstem is divided into three discrete parts (in ascending order): the medulla oblongata, the pons and the midbrain. The medulla is a continuation of the superior part of the spinal cord and measures about 3 cm in length. However, despite its small size, it houses the cardiovascular and respiratory centres, and coordinates a number of autonomic activities such as swallowing, coughing, sneezing, vomiting and hiccupping. Situated directly above the medulla is the widest section of the brainstem known as the pons (Latin for ‘bridge’). The pons attaches the brainstem to the cerebellum behind and contains the apneustic and pneumotaxic centres that help regulate respiratory rate and depth (see Chapter 9).
Modelling of intracranial behaviour on occiput impact in judo
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Ryutaro Suzuki, Masaki Omiya, Hiroaki Hoshino, Takeshi Kamitani, Yusuke Miyazaki
The brainstem connects the spinal cord and the cerebrum, and is modelled as a spring and damper element in the translational direction. The connection position of the brainstem cerebrum was determined with reference to an anatomical image (Ellis et al. 1999). In addition, the brainstem was fixed to the head at the first cervical vertebra (C1), which connects the head and neck. The force and displacement relation of the brainstem shown in Figure 5 was calculated with reference to the results of a tensile and compression test of a pig’s cerebral cortex (Miller and Chinzei 2002). The diameter and length of the brainstem were set to 20.4 mm and 90.9 mm, respectively. The damping coefficient of the damper element was set to 0.001 Ns/mm, which was calibrated from the cadaver experimental results.
Stress-induced expression pattern of glutamate signaling genes associated with anhedonia
Published in Stress, 2020
Nikolay N. Dygalo, Tatyana S. Kalinina, Galina T. Shishkina
Following decapitation, the brains were quickly removed, and the prefrontal cortex (Cort.), hippocampus (Hip.), amygdala (Amy.), midbrain (Mid.), and brainstem (Bst.) were rapidly isolated on ice, using the rat brain atlas coordinates (Paxinos & Watson, 1998), and immediately frozen in liquid nitrogen. The prefrontal cortex sample included a tissue section 1.5 mm thick cut from the between hemispheres surface approximately from AP (anterior-posterior) +4.5 to +2.2, L (lateral) 0–1.5 and DV (dorsal-ventral) 2 to 4.5 mm from the bregma. Hippocampal (AP +0.8 to −5.2, L 1-6 and DV 2-7 mm) and amygdala (AP −1.4 to −3.6, L 2-6 and DV 6.3–9 mm) samples were dissected from the brain. As previously described (Shishkina et al., 2007), the midbrain sample included the block of tissue from the rostral border of the superior colliculus to the rostral border of the pons to approximately −8.7 mm bregma. The brainstem that was caudal to the midbrain region included medulla oblongata.
Neuro-Ophthalmic Literature Review
Published in Neuro-Ophthalmology, 2019
David Bellows, Noel Chan, John Chen, Hui-Chen Cheng, Peter MacIntosh, Jenny Nij Bijvank, Michael Vaphiades, Konrad Weber, Sui Wong
First, all regions of the eye movement network and their (known) function are described, starting with cortical regions. This is accompanied by insightful figures and a table summarising the function, anatomical location, and regions of interest definition. In general, frontal and cingulate cortices are primarily involved in more internally driven (e.g. intentional and executive) components of eye movements, and the parietal cortex is involved in more externally driven (e.g. reflexive) components of eye movements. Occipital cortices contribute sensory functions. The thalamus and striatum are critical for the voluntary control of eye movements, and the cerebellum is crucial for the fine control – but not the initiation – of eye movements. The brainstem contains regions (e.g. superior colliculus and brainstem motor nuclei) that are more directly responsible for generating all eye movements.