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Stroke
Published in Henry J. Woodford, Essential Geriatrics, 2022
Thalamic infarction can cause a range of symptoms and signs. These include pure sensory strokes and some neuropsychological deficits. Amnesia can be caused by lesions affecting the limbic system (seeFigure 6.7), but other neurological deficits would be expected to occur simultaneously. Lesions affecting the basal ganglia may induce movement disorders, such as hemiballismus or focal dystonia. Bilateral vertebrobasilar atheromatous disease can lead to symptoms due to hypoperfusion of the brainstem provoked by stimuli that further reduce blood flow (see page 301). These include increases in antihypertensive medication or rapid postural change.20 Typically, multiple brief, stereotyped episodes occur and common symptoms include lightheadedness, dysarthria, ataxia, blurred vision and diplopia.
The Limbic System
Published in Jay A. Goldstein, Chronic Fatigue Syndromes, 2020
Thalamus. The anatomy of the thalamus is very complex. This structure functions as a relay station for sensory nerve input. The thalamic nuclei with which most physicians are familiar are the lateral basal nuclei which relay sensory information to the idiotypic cortex. Other areas in the lateral basal nuclei relay to the unimodal association cortex. Large areas, however, are relays for heteromodal, paralimbic, and limbic cortices. The function of these nuclei is not well understood. The reticular and intralaminal thalamic nuclei are relays from the reticular activating system and have diffuse cortical projections. Thalamic pain is a well-recognized neurologic entity caused by destructive lesions, often strokes, in the thalamus. This sort of pain presents with little sensory loss and is often accompanied with dysesthesias and paresthesias. A more inclusive term used to describe similar types of pain resulting from dysregulation of CNS pain pathways is “central pain.”
Neuroanatomy and Brain Perfusion in Functional Somatic Syndromes
Published in Peter Manu, The Psychopathology of Functional Somatic Syndromes, 2020
The authors’ interpretation of the data was based on their understanding of the functional differences in the pain-processing centers of the human brain. They believed that the thalamus is a relay station in the connection between the gastrointestinal tract and cortical centers; that the insular cortex is the processing area for all visceral inputs; and that the prefrontal cortex has the executive function with regard to pain perception. The anterior cingulate cortex was thought to integrate or produce the emotional response to visceral stimuli. The findings did not clarify “whether the anterior cingulate cortex itself is abnormally responsive [in irritable bowel syndrome], or merely responding appropriately to heightened visceral afferent signals” (Mertz et al., 2000, p. 846) and “did not rule out psychological causes of increased pain sensitivity” (p. 847). The lack of coupling between subjective assessment of pain and the degree of brain activation was interpreted as the result of cognitive and emotional factors.
Lateropulsion with active pushing in stroke patients: its link with lesion location and the perception of verticality. A systematic review
Published in Topics in Stroke Rehabilitation, 2023
Charlotte van der Waal, Elissa Embrechts, Renata Loureiro-Chaves, Nick Gebruers, Steven Truijen, Wim Saeys
Regions associated with LwP in multiple studies were the thalamus,30,31,35,36 inferior parietal lobule,7,28,35 pre-34,35 and postcentral gyrus28,34,35 and its surrounding white matter,7 posterior insula,7,35,36 the superior temporal gyrus7,35,36 and the internal capsule.29,30,36 Some specific parts of the thalamus were reported: the posterior part,31 the ventral and lateral posterior nuclei of the posterolateral thalamus with extension to the internal capsule30 and in the internal capsule reaching to the lateral thalamus.36 Of the extra-thalamic regions, one study found that lesions of the inferior parietal lobule at the junction of the postcentral gyrus, were positively associated with severe LwP (according the BLS).28 The whole insula34,35 and specific regions of the insula, its posterior7,36 and anterior part,36 were related to LwP. The following tracts and regions associated to LwP were only reported once: corticospinal tract,35 inferior occipitofrontal,35 uncinate fasciculi,35 external capsule,29 subgyral parietal lobe,34 inferior frontal gyrus,34 and (frontal and Rolandic) parts of the operculum.35,36
Regional shape alteration of left thalamus associated with late chronotype in young adults
Published in Chronobiology International, 2023
Cheng Xu, Hui Xu, Zhenliang Yang, Chenguang Guo
Furthermore, the thalamus is considered a hub region that transmits sensory and motor information between the cerebral cortex and subcortical areas and regulates sleep-wake patterns (Jan et al. 2009). On the one hand, studies have shown that the paraventricular nucleus of the thalamus is interconnected with the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus, receiving direct and indirect photic input, which plays a key role in the control of sleep and wakefulness (Colavito et al. 2015). In addition, the thalamus serves as an important regulatory point for melatonin to aid sleep and treat sleep disorders (Jan et al. 2009). Individuals with more severe thalamic damage have more difficulty in sleeping (Laniepce et al. 2019) and irregular circadian rhythms (Cruse et al. 2013). One study on Parkinson’s patients showed a significant positive correlation between daytime sleepiness and thalamic atrophy (Niccolini et al. 2019). Our study may explain LC young adults with higher CHQ-ME scores would suffer more severe thalamic morphological atrophy.
Thalamic neuromodulation in epilepsy: A primer for emerging circuit-based therapies
Published in Expert Review of Neurotherapeutics, 2023
Bryan Zheng, David D. Liu, Brian B Theyel, Hael Abdulrazeq, Anna R. Kimata, Peter M Lauro, Wael F. Asaad
Within this context of new neuromodulation therapies for epilepsy, the thalamus has garnered increasing attention in large part because its broad and highly robust connectivity with cortex makes it an intuitively attractive target for modulation. Though formerly viewed as a subcortical-cortical relay node with some modulatory influence on the transmitted information, the thalamus is now understood to play a substantial and critical role in processing information as it travels to, from, and between cortical areas. Its modular, canonical thalamocortical (TC) and corticothalamic (CT) projections are widely appreciated, but the thalamus also makes extensive connections with additional deep structures such as the hippocampus, amygdala, piriform lobule, and basal ganglia[18]. Nonetheless, our clinical models have yet to fully incorporate the improved understanding of thalamic anatomy, physiology, and pathology that has resulted from technical advances such as precise intracellular recordings, high-resolution imaging, and optogenetics.