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Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
♦ 1. What portion of the dorsal thalamus makes up its posterior nuclear group? For example, does it include: all, just some, or none of the medial geniculate body?all, just some, or none of the lateral geniculate body?all, just some, or none of the pulvinar?part or none of the ventral posterior nucleus?the suprageniculate nucleus?the limitans nucleus?a distinct “posterior nucleus”?
Neuroanatomy of basic cognitive function
Published in Mark J. Ashley, David A. Hovda, Traumatic Brain Injury, 2017
Mark J. Ashley, Jessica G. Ashley, Matthew J. Ashley
The thalamus is comprised of four groups of nuclei: the anterior, medial, ventral, and posterior.39 The anterior nucleus is a single nucleus that receives its major input from the mammillary nuclei of the hypothalamus and the presubiculum of the hippocampal formation. It is interconnected with the cingulate and frontal cortices and may be involved in memory. The medial nucleus is comprised of the mediodorsal nucleus, which has three subdivisions. Each of these projects to a particular region of the frontal cortex, and input is received from the basal ganglia, amygdala, and midbrain. The medial nucleus is also implicated in memory. The ventral nucleus is comprised of the ventral anterior and ventral lateral nuclei. These are involved in motor control. Input to these nuclei comes from the cerebellum and basal ganglia, and output is to the motor cortex. The ventral posterior nucleus, also part of the ventral nucleus, sends somatosensory information to the neocortex. Last, the posterior nucleus is made up of the medial geniculate, lateral geniculate, lateral posterior nuclei, and pulvinar. The medial geniculate nucleus receives tonotopic auditory stimulus and projects it to the superior temporal gyrus. The lateral geniculate receives information from the retina and projects it to the primary visual cortex.39
Central neuropathic pain: syndromes, pathophysiology, and treatments
Published in Peter R Wilson, Paul J Watson, Jennifer A Haythornthwaite, Troels S Jensen, Clinical Pain Management, 2008
Pertinent to thalamic pain syndromes caused by lenticulo-capsular hemorrhages (and one would presume lacunar ischemic infarcts in posterior limb of the internal capsule damaging thalamo-cortical pathways), it is notable that pain has been reported to disproportionately (or solely) affect the leg despite more widespread motor and sensory deficits. The somatotopic arrangement of the ventral posterior nucleus of the thalamus in primates from medial to lateral is face, arm, and leg most laterally (i.e. adjacent to the posterior limb of the internal capsule). This arrangement also appears to hold in thalamocortical projections from this nucleus and hence a lesion (hemorrhagic or presumably lacunar) could affect these projections or the most lateral portions of the ventral-posterior thalamus explaining this leg predominant clinical central pain picture.37
Retinal optical coherence tomography and magnetic resonance imaging in neuromyelitis optica spectrum disorders and MOG-antibody associated disorders: an updated review
Published in Expert Review of Neurotherapeutics, 2021
Ting-Yi Lin, Claudia Chien, Angelo Lu, Friedemann Paul, Hanna G. Zimmermann
Using DGM atlas-based analysis, subregions of the thalamus have been investigated that are part of the visual pathway. The LGN is a central node in the visual pathway, allowing for signaling between the retina and the visual cortex. Smaller LGN volumes were discovered in AQP4-ON patients, but not in AQP4-NON patients or healthy subjects [257]. In addition, LGN volume also have a correlation with the number of ON episodes, but does not seem to have correlation with the optic radiation lesion [257]. These results not only enlightened the clinical utility of various MRI parameters assessing the optic pathway degeneration, but also suggested an anterograde degeneration in the afferent visual pathway [258]. Apart from the thalamic subregions associated with the visual pathway, the volume of the ventral posterior nucleus, which receives sensory input from the spinothalamic tracts, was found to be inversely correlated with pain severity in AQP-IgG seropositive NMOSD patients [224].
A primary cilium in oligodendrocytes: a fine structure signal of repairs in thalamic Osmotic Demyelination Syndrome (ODS)
Published in Ultrastructural Pathology, 2021
Jacques Gilloteaux, Joanna Bouchat, Valery Bielarz, Jean-Pierre Brion, Charles Nicaise
(the ventral posterior nucleus) 1-µm semi-thin sections, histology enabled us to recognize the different cell types within those regions investigated. Examples of each treatment-sampled regions are displayed in Figure 3 as Control/Sham treated or Normonatremic (NN), Hyponatremic (HN), 12-h post ODS or ODS12h, and 48-h ODS or ODS48h treated. There, neuron somata, macroglial (astrocytes and oligodendrocytes) and some spaces, have been exemplified and labeled. including capillaries and some of the hollows caused by myelinolysis neuropil. Following those treatments, neuron cell bodies, astrocytes, and oligodendrocytes as well as microgliocytes did not appear to show very obvious damage under light microscope examination save immunolabels, and then ultrastructure observations complemented the changes revealed by those molecular markers. However, after comparisons and scrutiny of the oligodendrocytes found in all the semi-thin sections, the HN treated suggested changes in overall cell morphology and topology of the NN nucleus aspects, as illustrated in Figure 3 HN. The same cells recognized in ODS12h treatment displayed the highest basophilic nucleus contrast while those of ODS48h are with euchromatic aspects, more like the NN type, whether they were satellites or interfibrillar oligodendrocytes (Fig 3 ODS48h).
Peripheral nerve stimulation: black, white and shades of grey
Published in British Journal of Neurosurgery, 2019
Viraat Harsh, Parijat Mishra, Preeti K Gond, Anil Kumar
The Gate Control hypothesis, which is currently the most widely accepted hypothesis, as proposed by Melzack and Wall1 published in Science 1965, explains the manner in which PNS works. The small diameter C fibres inhibit whereas the large diameter Aδ fibres excite the substantia gelatinosa, the overall inhibitory effect of which determines the nociceptive input and regulates its transmission to the cerebral cortex through the anterolateral system via the ventral posterior nuclei of the thalamus. The Aδ fibres inhibit the nociceptive input, thereby decreasing pain sensation. Aδ fibres having a lower threshold, get stimulated first, thus shutting the gate and inhibiting transmission of pain via the C fibres2. This implies that constant stimulation of Aδ fibres can diminish the transmission of pain at the level of spinal cord or medulla. This hypothesis was demonstrated by Ellrich and Lamp3 in 2005.