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Pediatric Blood & Cancer Feb 2021Children with brain tumors experience cognitive late effects, often related to cranial radiation. We sought to determine differential effects of surgery and chemotherapy...
PURPOSE
Children with brain tumors experience cognitive late effects, often related to cranial radiation. We sought to determine differential effects of surgery and chemotherapy on brain structure and neuropsychological outcomes in children who did not receive cranial radiation therapy (CRT).
METHODS
Twenty-eight children with a history of posterior fossa tumor (17 treated with surgery, 11 treated with surgery and chemotherapy) underwent neuroimaging and neuropsychological assessment a mean of 4.5 years (surgery group) to 9 years (surgery + chemotherapy group) posttreatment, along with 18 healthy sibling controls. Psychometric measures assessed IQ, language, executive functions, processing speed, memory, and social-emotional functioning. Group differences and correlations between diffusion tensor imaging findings and psychometric scores were examined.
RESULTS
The z-score mapping demonstrated fractional anisotropy (FA) values were ≥2 standard deviations lower in white matter tracts, prefrontal cortex gray matter, hippocampus, thalamus, basal ganglia, and pons between patient groups, indicating microstructural damage associated with chemotherapy. Patients scored lower than controls on visuoconstructional reasoning and memory (P ≤ .02). Lower FA in the uncinate fasciculus (R = -0.82 to -0.91) and higher FA in the thalamus (R = 0.73-0.91) associated with higher IQ scores, and higher FA in the thalamus associated with higher scores on spatial working memory (R = 0.82).
CONCLUSIONS
Posterior fossa brain tumor treatment with surgery and chemotherapy affects brain microstructure and neuropsychological functioning years into survivorship, with spatial processes the most vulnerable. Biomarkers indicating cellular changes in the thalamus, hippocampus, pons, prefrontal cortex, and white matter tracts associate with lower psychometric scores.
Topics: Adolescent; Anisotropy; Antineoplastic Agents; Brain Injuries; Brain Neoplasms; Child; Cross-Sectional Studies; Female; Hippocampus; Humans; Infratentorial Neoplasms; Male; Neuropsychological Tests; Neurotoxicity Syndromes; Pons; Prefrontal Cortex; Psychometrics; Thalamus; White Matter
PubMed: 33251768
DOI: 10.1002/pbc.28817 -
European Neurology 2023A solitary pontine lesion (SPL) is a single brainstem lesion on the trigeminal nerve pathway without any other central nervous system lesion. This research aimed to...
A solitary pontine lesion (SPL) is a single brainstem lesion on the trigeminal nerve pathway without any other central nervous system lesion. This research aimed to investigate the demographic and clinical features of nonpainful TNO patients with SPL and identify the most frequently affected anatomical areas using lesion mapping techniques. Demographic and clinical features were retrospectively reviewed from the patients' charts. Brain lesions were mapped using MRIcroGL software. The study included 6 patients (three females and three males) with an SPL. The median age of the patients was 57 (range: 46-68) years. Cranial MRI displayed lesions in the dorsolateral pons and the cerebellar peduncle. The lesion mapping revealed that the lesions were on the trigeminal nerve pathway. SPL is an uncommon cause of TNO. Nonpainful SPL patients have demographic, clinical, and radiological features similar to those of painful SPL patients. The lesion mapping showed that the same brainstem areas are affected in painful and nonpainful SPL patients.
Topics: Male; Female; Humans; Middle Aged; Aged; Retrospective Studies; Pons; Trigeminal Nerve Diseases; Trigeminal Nerve; Brain Stem; Magnetic Resonance Imaging
PubMed: 36689918
DOI: 10.1159/000528470 -
Trends in Cognitive Sciences Jun 2022Neural dynamics are shaped and constrained by the projections of a small nucleus in the pons: the noradrenergic locus coeruleus (LC). Much like a bow to the brain's... (Review)
Review
Neural dynamics are shaped and constrained by the projections of a small nucleus in the pons: the noradrenergic locus coeruleus (LC). Much like a bow to the brain's violin, activity in the LC lacks content specificity, but instead dynamically shapes the excitability and receptivity of neurons across the brain. In this review, we explain how the style of the bowing technique, which is analogous to different firing modes in the LC, affects distinct activity patterns in the rest of the brain. Through this analogical lens, we provide intuitive insights into how the complex activity of the LC acts to coordinate adaptive neural dynamics.
Topics: Humans; Locus Coeruleus; Neurons
PubMed: 35469726
DOI: 10.1016/j.tics.2022.03.006 -
Scientific Reports Mar 2021Multisensory integration of auditory and tactile information occurs already at the level of the cochlear nucleus. Rodents use their whiskers for tactile perception to...
Multisensory integration of auditory and tactile information occurs already at the level of the cochlear nucleus. Rodents use their whiskers for tactile perception to guide them in their exploration of the world. As nocturnal animals with relatively poor vision, audiotactile interactions are of great importance for this species. Here, the influence of whisker deflections on sound-evoked spiking in the cochlear nucleus was investigated in vivo in anesthetized mice. Multichannel, silicon-probe electrophysiological recordings were obtained from both the dorsal and ventral cochlear nucleus. Whisker deflections evoked an increased spiking activity in fusiform cells of the dorsal cochlear nucleus and t-stellate cells in ventral cochlear nucleus, whereas bushy cells in the ventral cochlear nucleus showed a more variable response. The response to broadband noise stimulation increased in fusiform cells and primary-like bushy cells when the sound stimulation was preceded (~ 20 ms) by whisker stimulation. Multi-sensory integration of auditory and whisker input can thus occur already in this early brainstem nucleus, emphasizing the importance of early integration of auditory and somatosensory information.
Topics: Acoustic Stimulation; Animals; Cochlear Nucleus; Electric Stimulation; Evoked Potentials, Somatosensory; Male; Mice; Mice, Inbred C57BL; Neural Inhibition; Neurons; Sensation; Vibrissae
PubMed: 33767295
DOI: 10.1038/s41598-021-86236-9 -
Parkinsonism & Related Disorders Sep 2021This study aimed to evaluate whether novel individual voxel-based morphometry adjusting covariates (iVAC), such as age, sex, and total intracranial volume, could...
INTRODUCTION
This study aimed to evaluate whether novel individual voxel-based morphometry adjusting covariates (iVAC), such as age, sex, and total intracranial volume, could increase the accuracy of a diagnosis of multiple system atrophy (MSA) and enable the differentiation of MSA from Parkinson's disease (PD).
METHODS
We included 53 MSA patients (MSA-C: 33, MSA-P: 20), 53 PD patients, and 189 healthy controls in this study. All participants underwent high-resolution T1-weighted imaging (WI) and T2-WI with a 3.0-T MRI scanner. We evaluated the occurrence of significant atrophic findings in the pons/middle cerebellar peduncle (MCP) and putamen on iVAC and compared these findings with characteristic changes on T2-WI.
RESULTS
On iVAC, abnormal findings were observed in the pons/MCP of 96.2% of MSA patients and in the putamen of 80% of MSA patients; however, on T2-WI, they were both observed at a frequency of 60.4% in MSA patients. On iVAC, all but one MSA-P patient (98.1%) showed significant atrophic changes in the pons/MCP or putamen. By contrast, 69.8% of patients with MSA showed abnormal signal changes in the pons/MCP or putamen on T2-WI. iVAC yielded 95.0% sensitivity and 96.2% specificity for differentiating MSA-P from PD.
CONCLUSION
iVAC enabled us to recognize the morphological characteristics of MSA visually and with high accuracy compared to T2-WI, indicating that iVAC is a potential diagnostic screening tool for MSA.
Topics: Adult; Aged; Case-Control Studies; Diagnosis, Differential; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Middle Cerebellar Peduncle; Multiple System Atrophy; Parkinson Disease; Pons; Putamen; Reproducibility of Results; Sensitivity and Specificity
PubMed: 34481140
DOI: 10.1016/j.parkreldis.2021.07.025 -
Neurology India 2022
Topics: Humans; Trigeminal Nerve Diseases; Brain Stem Infarctions; Pons; Trigeminal Neuralgia; Trigeminal Nerve
PubMed: 36352696
DOI: 10.4103/0028-3886.359199 -
ELife Feb 2022Long-lasting negative affections dampen enthusiasm for life, and dealing with negative affective states is essential for individual survival. The parabrachial nucleus...
Long-lasting negative affections dampen enthusiasm for life, and dealing with negative affective states is essential for individual survival. The parabrachial nucleus (PBN) and thalamic paraventricular nucleus (PVT) are critical for modulating affective states in mice. However, the functional roles of PBN-PVT projections in modulating affective states remain elusive. Here, we show that PBN neurons send dense projection fibers to the PVT and form direct excitatory synapses with PVT neurons. Activation of the PBN-PVT pathway induces robust behaviors associated with negative affective states without affecting nociceptive behaviors. Inhibition of the PBN-PVT pathway reduces aversion-like and fear-like behaviors. Furthermore, the PVT neurons innervated by the PBN are activated by aversive stimulation, and activation of PBN-PVT projections enhances the neuronal activity of PVT neurons in response to the aversive stimulus. Consistently, activation of PVT neurons that received PBN-PVT projections induces anxiety-like behaviors. Thus, our study indicates that PBN-PVT projections modulate negative affective states in mice.
Topics: Animals; Mice; Neurons; Parabrachial Nucleus; Synapses
PubMed: 35167440
DOI: 10.7554/eLife.68372 -
Journal of Neuroscience Research Nov 2021The pons is one of the earliest affected regions in patients with synucleinopathies. We aimed to investigate the diagnostic value of measuring pontine damage using...
The pons is one of the earliest affected regions in patients with synucleinopathies. We aimed to investigate the diagnostic value of measuring pontine damage using diffusion tensor imaging (DTI) in these patients. We enrolled 49 patients with Parkinson's disease (PD), 16 patients with idiopathic rapid eye movement sleep behavior disorder (iRBD), 23 patients with multiple system atrophy (MSA), and 39 healthy controls in this study. All the participants underwent high-resolution T1-weighted imaging and DTI. Mean diffusivity (MD) and fraction anisotropy (FA) values in the pons were calculated to characterize structural damage. The discriminatory power of pontine MD and FA values to differentiate patients with synucleinopathies from healthy controls was examined using receiver operating characteristics (ROC) analyses. Compared to healthy controls, patients with PD, iRBD, and MSA had increased MD values and decreased FA values in the pons, although no correlation was observed between these DTI measures and disease severity. The ROC analyses showed that MD values in the pons had a fair discriminatory power to differentiate healthy controls from patients with PD (area under the curve [AUC], 0.813), iRBD (AUC, 0.779), and MSA (AUC, 0.951). The AUC for pontine FA values was smaller than that for pontine MD values when differentiating healthy controls from patients with PD (AUC, 0.713; p = 0.054) and iRBD (AUC, 0.686; p = 0.045). Our results suggest that MD values in the pons may be a useful marker of brain stem neurodegeneration in patients with synucleinopathies.
Topics: Anisotropy; Diffusion Tensor Imaging; Humans; Pons; REM Sleep Behavior Disorder; Synucleinopathies
PubMed: 34521154
DOI: 10.1002/jnr.24926 -
Journal of Neurology Aug 2022Pontine infarctions are often associated with extrapontine infarcts. We aimed to elucidate differences in clinical characteristics, mechanisms, and functional outcomes...
BACKGROUND
Pontine infarctions are often associated with extrapontine infarcts. We aimed to elucidate differences in clinical characteristics, mechanisms, and functional outcomes between isolated pontine infarction (IPI) and pontine plus infarction (PPI).
METHODS
We studied patients with acute pontine infarction between January 2019 and August 2021 and divided them into IPI and PPI according to diffusion-weighted magnetic resonance image. Vertical locations were classified into rostral, middle, and caudal, and horizontal locations were categorized as basal/tegmental and unilateral/bilateral. Factors associated with poor 90-day outcome (modified Rankin scale 3-6) were analyzed.
RESULTS
Among 241 patients, 170 (70.5%) had IPI and 71 (29.5%) had PPI. The most frequently observed extrapontine areas were cerebellar (59.1%), followed by posterior cerebral artery territory (45.1%). Mental status changes, sensory changes, and ataxia were more common, and motor dysfunction was less common in PPI patients. The PPI patients more often had rostral (P < 0.001), bilateral lesions (P < 0.001), and moderate/severe vascular stenosis and atrial fibrillation; therefore, large artery disease (LAD) and cardioembolism were more common stroke mechanisms (P < 0.001). In IPI patients, high initial National Institutes of Health Stroke Scale (NIHSS) (adjusted Odds ratio (OR) = 1.38; P = 0.001) and old age (aOR = 1.05; P = 0.049) were associated with poor functional outcome, whereas moderate/severe stenosis (Reference: no stenosis, aOR = 7.17; P = 0.014) and high initial NIHSS (aOR = 1.39; P = 0.006) were related to unfavorable outcomes in PPI patients.
CONCLUSIONS
PPI patients more often had extensive pontine lesions, LAD and cardioembolism, and their outcome was more often influenced by underlying severe vascular diseases. These differences need to be considered in the prevention and therapeutic strategies.
Topics: Brain Stem Infarctions; Constriction, Pathologic; Humans; Infarction; Pons; Prevalence; Stroke
PubMed: 35318490
DOI: 10.1007/s00415-022-11075-1 -
Neuroscience Sep 2020Itch induces a desire to scratch and leads to skin damage in some severe conditions. Much progress has been made in the peripheral and spinal level, and recent findings...
Itch induces a desire to scratch and leads to skin damage in some severe conditions. Much progress has been made in the peripheral and spinal level, and recent findings suggested that we need to focus on the central circuitry mechanism. However, the functional role of the thalamus in itch signal processing remains largely unknown. We showed that the posterior thalamic nucleus (Po) played a vital role in modulating facial histaminergic itch signal processing. We found that the calcium signal of Po neurons was increased during the histaminergic itch-induced scratching behavior in the cheek model, and pharmacogenetic suppression of Po neurons reduced the scratching behaviors. Retrograde mapping results suggested that the Po receives information from the somatosensory cortex, motor cortex, parabrachial nucleus (PBN), the principal sensory trigeminal nucleus (PrV) and the spinal trigeminal nucleus (SpV), which participate in itch signal transmission from head and body. Thus, our study indicates that the Po is critical in modulating facial histaminergic itch signal processing.
Topics: Humans; Parabrachial Nucleus; Posterior Thalamic Nuclei; Pruritus; Somatosensory Cortex; Trigeminal Nucleus, Spinal
PubMed: 32750381
DOI: 10.1016/j.neuroscience.2020.07.048