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The Central Connections of Area Postrema Define the Paraventricular System Involved in Antinoxious Behaviors
Published in John Kucharczyk, David J. Stewart, Alan D. Miller, Nausea and Vomiting: Recent Research and Clinical Advances, 2017
Given that the paraventricular system participates in nausea, vomiting, and conditioned taste aversion, it might be anticipated that abnormalities in its component nuclei would affect eating and drinking. Feeding and drinking have been altered by stimulation or destruction of the bed nucleus of stria terminalis;77 the amygdala, particularly its central and medial nuclei;78 the paraventricular,79 ventromedial,80 and dorsomedial81 nuclei of the hypothalamus; the periventricular nucleus of thalamus; and the periaqueductal gray matter82 and nucleus tractus solitarius.83 Low intensity stimulation of the hypothalamus inhibited milk drinking in cats.84 Hyperphagia resulted from lesions coinciding with the pathway from the paraventricular nucleus.82 The zona incerta has been implicated in feeding and drinking.85 Lesions of area postrema and nucleus tractus solitarius resulted in lowered body weight,86 an initial hypophagia and hypodipsia, leading to an enhanced responsiveness to palatable food87 or a disinterest in food.65 Water intake was increased after chronic lesions of area postrema.87
ENTRIES A–Z
Published in Philip Winn, Dictionary of Biological Psychology, 2003
A narrow structure situated between the THALAMUS and the HYPOTHALAMUS that contains scattered neurons and intermixed fibres. The anterior part of zona incerta is continuous with the RETICULAR NUCLEUS OF THE THALAMUS. The zona incerta receives a projection from the MOTOR CORTEX, and projects to the RED NUCLEUS, SUPERIOR COLLICULUS and the pretectal (see PRETECTUM) area, suggesting its role in visuomotor coordination. The zona incerta also appears to be involved in limbic (see LIMBIC SYSTEM) and AUTONOMIC functions, as some of its neurons project to the MIDBRAIN PERIAQUEDUCTAL GREY and the PARABRACHIAL NUCLEI in the PONS.
Spinal cord stimulation for gait disturbances in Parkinson’s disease
Published in Expert Review of Neurotherapeutics, 2023
Nora Vanegas-Arroyave, Joseph Jankovic
Deep brain stimulation (DBS) has been an effective treatment for the motor symptoms of PD. However, gait disturbances are not consistently alleviated by DBS, and, in some cases, they may even appear de novo or worsen postoperatively [20–24]. Transient improvement of axial symptoms including gait in PD has been demonstrated using low-frequency (80 Hz) stimulation [25] and there is evidence of superior effects of closed loop DBS, to suppress beta band activity within the STN and reduce FOG during a stepping in place task [26]. In addition to conventional, DBS targets (STN and Globus pallidus – GPi), studies in nonhuman primates have suggested that dysfunction of the pedunculopontine nucleus (PPN) is at least partly responsible for the axial motor symptoms and particularly gait issues associated with PD [8]. Interestingly, the PPN is highly connected to the GPi, the cerebellum, and the spinal cord [27]. Cholinergic neurons of the PPN and their projections are known to be particularly important for locomotion and it has been postulated that the PPN may function as an integrative interface between various brainstem and subcortical structures involved in locomotion. However, human studies of PPN DBS have reported marked outcome variability [28–32] and the use of PPN DBS for FOG continues to be an investigational procedure. Additional targets, including the zona incerta, the cuneiform nucleus, and the substantia nigra, have been investigated in small series of patients. To date, information on the efficacy of these new targets is limited.
Deep brain stimulation in essential tremor: targets, technology, and a comprehensive review of clinical outcomes
Published in Expert Review of Neurotherapeutics, 2020
Joshua K. Wong, Christopher W. Hess, Leonardo Almeida, Erik H. Middlebrooks, Evangelos A. Christou, Erin E. Patrick, Aparna Wagle Shukla, Kelly D. Foote, Michael S. Okun
The zona incerta (ZI) is another alternative target that has been used for ET DBS. One study sought to compare differences in zona incerta (ZI) DBS versus VIM DBS in a retrospective review of 47 DBS patients [51]. After DBS implantation, a delayed post-operative head CT was fused to the pre-operative targeting MRI for 3-D lead localization. These images were then further fused with a patient-specific, deformed 3-D anatomic atlas via the Schaltenbrand–Bailey Sudhyadhom technique [52]. The active DBS contact was identified in 3-D space with respect to the anterior commissure – posterior commissure (AC-PC) line. Active contacts above the AC-PC line were categorized as VIM whereas contacts below the AC-PC line were categorized as caudal zona incerta (cZI). The authors found that short-term benefits (at 6 months and 2 years) compared to baseline were similar between the VIM and cZI. However, at 3- and 4-years post DBS implantation, VIM DBS provided better tremor suppression (p < 0.01). Analysis of the trend over time also revealed that Fahn-Tolosa-Marin Tremor Rating Scale (TRS) scores in VIM DBS trended down over time whereas TRS scores trended up in cZI DBS (tau = 0.26, p < 0.01) [53]. The authors also observed that VIM DBS required lower voltage settings to obtain tremor suppression at 3 years postDBS implantation (2.55 v vs 3.17 v, p < 0.001). There were no significant differences between the other programming parameters.