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Cerebellar Peduncle (cerebellar + peduncle)
Kinds of Cerebellar Peduncle Selected AbstractsEyeblink conditioning using cochlear nucleus stimulation as a conditioned stimulus in developing ratsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2008John H. Freeman Abstract Previous studies demonstrated that the development of auditory conditioned stimulus (CS) input to the cerebellum may be a neural mechanism underlying the ontogenetic emergence of eyeblink conditioning in rats. The current study investigated the role of developmental changes in the projections of the cochlear nucleus (CN) in the ontogeny of eyeblink conditioning using electrical stimulation of the CN as a CS. Rat pups were implanted with a bipolar stimulating electrode in the CN and given six 100-trial training sessions with a 300 ms stimulation train in the CN paired with a 10 ms periorbital shock unconditioned stimulus (US) on postnatal days (P) 17,18 or 24,25. Control groups were given unpaired presentations of the CS and US. Rats in both age groups that received paired training showed significant increases in eyeblink conditioned responses across training relative to the unpaired groups. The rats trained on P24,25, however, showed stronger conditioning relative to the group trained on P17,18. Rats with missed electrodes in the inferior cerebellar peduncle or in the cerebellar cortex did not show conditioning. The findings suggest that developmental changes in the CN projections to the pons, inferior colliculus, or medial auditory thalamus may be a neural mechanism underlying the ontogeny of auditory eyeblink conditioning. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 640-646, 2008. [source] Correlation of anatomy and function in medulla oblongata infarctionEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2009C. Eggers Background:, A presentation of all aspects of the dorsolateral medulla oblongata syndrome is clinically very rare to find. In most cases patients present with fragmentary symptoms, e.g. ipsilateral axial lateropulsion, nystagmus, dysarthria, dysphagia or hemiataxia. However, the clinical presentation and lesion anatomy at the level of the medulla oblongata is still unsatisfactory. The aim of this study was to correlate the functional deficit with structural MRI-data. Methods:, We included thirteen patients (eight male, five female, mean age 65.5) with medulla oblongata infarction with clinically predominant ipsilateral axial lateropulsion and correlated clinical with structural deficits. Results:, Magnetic resonance imaging lesion mapping demonstrated ipsilateral axial lateropulsion to result from lesions of the spinocerebellar tract, the inferior cerebellar peduncle or the inferior vestibular nucleus. Nystagmus was associated with lesions of the inferior vestibular nucleus, dissociated sensory loss with the spinothalamic tract and hemiataxia with the spinocerebellar tract. Conclusions:, Correlating dysfunction and lesion anatomy is a promising approach to enhance our knowledge on medulla oblongata topography. [source] Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum DisorderALCOHOLISM, Issue 2 2010Catherine Lebel Background:, Children with fetal alcohol spectrum disorder (FASD) often demonstrate a variety of cognitive deficits, but mathematical ability seems to be particularly affected by prenatal alcohol exposure. Parietal brain regions have been implicated in both functional and structural studies of mathematical ability in healthy individuals, but little is known about the brain structure underlying mathematical deficits in children with FASD. The goal of this study was to use diffusion tensor imaging (DTI) to investigate the relationship between mathematical skill and brain white matter structure in children with FASD. Methods:, Twenty-one children aged 5 to 13 years diagnosed with FASD underwent DTI on a 1.5-T MRI scanner and cognitive assessments including the Woodcock-Johnson Quantitative Concepts test. Voxel-based analysis was conducted by normalizing subject images to a template and correlating fractional anisotropy (FA) values across the brain white matter with age-standardized math scores. Results:, Voxel-based analysis revealed 4 clusters with significant correlations between FA and math scores: 2 positively-correlated clusters in the left parietal region, 1 positively-correlated cluster in the left cerebellum, and 1 negatively-correlated cluster in the bilateral brainstem. Diffusion tractography identified the specific white matter tracts passing through these clusters, namely the left superior longitudinal fasciculus, left corticospinal tract and body of the corpus callosum, middle cerebellar peduncle, and bilateral projection fibers including the anterior and posterior limbs of the internal capsule. Conclusions:, These results identify 4 key regions related to mathematical ability and provide a link between brain microstructure and cognitive skills in children with FASD. Given previous findings in typically developing children and those with other abnormal conditions, our results highlight the consistent importance of the left parietal area for mathematical tasks across various populations, and also demonstrate other regions that may be specific to mathematical processing in children with FASD. [source] Apparent diffusion coefficient of the superior cerebellar peduncle differentiates progressive supranuclear palsy from Parkinson's disease,MOVEMENT DISORDERS, Issue 16 2008Giuseppe Nicoletti MD Abstract The early diagnosis of progressive supranuclear palsy (PSP) may be challenging, because of clinical overlapping features with Parkinson's disease (PD) and other parkinsonian syndromes such as the Parkinsonian variant of multiple system atrophy (MSA-P). Conventional MRI can help in differentiating parkinsonian disorders but its diagnostic accuracy is still unsatisfactory. On the basis of the pathological demonstration of superior cerebellar peduncle (SCP) atrophy in patients with PSP, we assessed the SCP apparent diffusion coefficient (ADC) values in patients with PSP, PD, and MSA-P in order to evaluate its differential diagnostic value in vivo. Twenty-eight patients with PSP (14 with possible-PSP and 14 with probable-PSP), 15 PD, 15 MSA-P, and 16 healthy subjects were studied by using diffusion weighted imaging (DWI). ADC was calculated in regions of interest defined in the left and right SCP by two clinically blinded operators. Intrarater (r = 0.98, P < 0.001) and interrater reliability (r = 0.97; P < 0.001) for SCP measurements were high. Patients with PSP had higher SCP rADC values (median 0.98 × 10,3mm2/s) than patients with PD (median 0.79 × 10,3 mm2/s, P < 0.001), MSA-P (median 0.79 × 10,3 mm2/s, P < 0.001), and healthy controls (median 0.80 × 10,3 mm2/s, P < 0.001). DWI discriminated patients with PSP from PD and healthy subjects on the basis of SCP rADC individual values (100% sensitivity and specificity) and from patients with MSA-P (96.4% sensitivity and 93.3% specificity). The higher values of rADC in SCP of patients with PSP correspond with the in vivo microstructural feature of atrophy detected postmortem and provide an additional support for early discrimination between PSP and other neurodegenerative parkinsonisms. © 2008 Movement Disorder Society [source] Microstructural white matter changes in primary torsion dystoniaMOVEMENT DISORDERS, Issue 2 2008Maren Carbon MD Abstract Primary torsion dystonia (PTD) has been conceptualized as a disorder of the basal ganglia. However, recent data suggest a widespread pathology involving motor control pathways. In this report, we explored whether PTD is associated with abnormal anatomical connectivity within motor control pathways. We used diffusion tensor magnetic resonance imaging (DT-MRI) to assess the microstructure of white matter. We found that fractional anisotropy, a measure of axonal integrity and coherence, was significantly reduced in PTD patients in the pontine brainstem in the vicinity of the left superior cerebellar peduncle and bilaterally in the white matter of the sensorimotor region. Our data thus support the possibility of a disturbance in cerebello-thalamo-cortical pathways as a cause of the clinical manifestations of PTD. © 2007 Movement Disorder Society [source] Diffusion-weighted magnetic resonance imaging differentiates Parkinsonian variant of multiple-system atrophy from progressive supranuclear palsyMOVEMENT DISORDERS, Issue 1 2007Dominic C. Paviour PhD, MRCP Abstract Progressive supranuclear palsy (PSP) and the parkinsonian variant of multiple-system atrophy (MSA-P) may present with a similar phenotype. Magnetic resonance diffusion-weighted imaging (DWI) has been shown to be a sensitive discriminator of MSA-P from Parkinson's disease (PD). We studied 20 PSP, 11 MSA-P, 12 PD patients and 7 healthy controls in order to investigate whether regional apparent diffusion coefficients (rADCs) help distinguish PSP and MSA-P; whether rADCs are correlated with clinical disease severity scores; and the relationship between brainstem and cerebellar volumes and rADCs in PSP and MSA-P. The Unified Parkinson's Disease Rating Scale, Hoehn and Yahr score, Mini Mental State Examination, and frontal assessment battery were recorded in all patients. Regional ADCs were measured in the middle cerebellar peduncle (MCP), caudal and rostral pons, midbrain, decussating fibers of the superior cerebellar peduncle, thalamus, putamen, globus pallidus, caudate nucleus, corpus callosum, frontal and parietal white matter, as well as the centrum semiovale. In MSA-P, rADCs in the MCP and rostral pons were significantly greater than in PSP (P < 0.001 and 0.009) and PD (P < 0.001 and = 0.002). Stepwise logistic regression revealed that the MCP rADC distinguishes MSA-P from PSP with a sensitivity of 91% and a specificity of 84%. Increased brainstem rADCs were associated with motor deficit in MSA-P and PSP. Increased rADCs in the pons and MCP were associated with smaller pontine and cerebellar volumes in MSA-P. rADCs distinguish MSA-P from PSP. These have a clinical correlate and are associated with reduced brainstem and cerebellar volumes. © 2006 Movement Disorder Society [source] Progressive Supranuclear Palsy: Pathology and GeneticsBRAIN PATHOLOGY, Issue 1 2007Dennis W. Dickson Progressive supranuclear palsy (PSP) is an atypical Parkinsonian disorder associated with progressive axial rigidity, vertical gaze palsy, dysarthria and dysphagia. Neuropathologically, the subthalamic nucleus and brainstem, especially the midbrain tectum and the superior cerebellar peduncle, show atrophy. The substantia nigra shows loss of pigment corresponding to nigrostriatal dopaminergic degeneration. Microscopic findings include neuronal loss, gliosis and neurofibrillary tangles in basal ganglia, diencephalon and brainstem. Characteristic tau pathology is also found in glia. The major genetic risk factor for sporadic PSP is a common variant in the gene encoding microtubule-associated protein tau (MAPT) and recent studies have suggested that this may result in the altered expression of specific tau protein isoforms. Imaging studies suggest that there may be sensitive and specific means to differentiate PSP from other parkinsonian disorders, but identification of a diagnostic biomarker is still elusive. [source] Age-related white matter lesions are associated with reduction of the apparent diffusion coefficient in the cerebellumEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2007P. Bugalho Cerebellar apparent diffusion coefficient (ADC) was found to be increased after acute cerebral hemispheric stroke. There are no data on cerebellar ADC changes in patients with chronic, age-related white matter lesions (ARWML). We aimed to determine longitudinal ADC variations on cerebral hemispheric and cerebellar white matter regions of patients with ARWML in order to study relations between ADC changes in both regions. ADC was measured serially (1-year interval) on lesioned periventricular frontal white matter, frontal and parietoccipital normal appearing white matter and middle cerebellar peduncles, on 19 aged patients with ARWML, which also underwent gait assessment. We compared regional ADC at 0 and 1 year and calculated variation percentages for each region. Correlation analysis was made between ADC variation in cerebellar regions and in contralateral hemispheric regions and between cerebellar ADC at 1 year and walking speed. After 1 year, ADC was higher on lesioned periventricular frontal white matter and lower on cerebellar regions. ADC variations on these regions were negatively correlated. Cerebellar ADC measured after 1 year was positively correlated with walking speed. This suggests a link between vascular disease progression inside frontal lesions and ADC reduction in contralateral cerebellar peduncles. Chronic ischemia in frontal white matter could have interrupted frontal-cerebellar circuits, producing hypometabolism in cerebellar regions (and worse performance on motor tasks), decreased perfusion and hence ADC reduction. [source] A multiparametric evaluation of regional brain damage in patients with primary progressive multiple sclerosisHUMAN BRAIN MAPPING, Issue 9 2009Antonia Ceccarelli Abstract The purpose of this study is to define the topographical distribution of gray matter (GM) and white matter (WM) damage in patients with primary progressive multiple sclerosis (PPMS), using a multiparametric MR-based approach. Using a 3 Tesla scanner, dual-echo, 3D fast-field echo (FFE), and diffusion tensor (DT) MRI scans were acquired from 18 PPMS patients and 17 matched healthy volunteers. An optimized voxel-based (VB) analysis was used to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain. In PPMS patients, GM atrophy was found in the thalami and the right insula, while mean diffusivity (MD) changes involved several cortical-subcortical structures in all cerebral lobes and the cerebellum. An overlap between decreased WM fractional anisotropy (FA) and increased WM MD was found in the corpus callosum, the cingulate gyrus, the left short temporal fibers, the right short frontal fibers, the optic radiations, and the middle cerebellar peduncles. Selective MD increase, not associated with FA decrease, was found in the internal capsules, the corticospinal tracts, the superior longitudinal fasciculi, the fronto-occipital fasciculi, and the right cerebral peduncle. A discrepancy was found between regional WM diffusivity changes and focal lesions because several areas had DT MRI abnormalities but did not harbor T2-visible lesions. Our study allowed to detect tissue damage in brain areas associated with motor and cognitive functions, which are known to be impaired in PPMS patients. Combining regional measures derived from different MR modalities may be a valuable tool to improve our understanding of PPMS pathophysiology. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc. [source] Clinical and pathological effects of short-term cyanide repeated dosing to goatsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2005B. Soto-Blanco Abstract The purpose of this work is to determine and describe the effects of subacute cyanide toxicity to goats. Eight female goats were divided into two groups. The first group of five animals was treated with 8.0 mg KCN kg,1 body weight day,1 for seven consecutive days. The second group of three animals was treated with water as controls. Complete physical examination, including observation for behavior changes, was conducted before and after dosing. One treated animal was euthanized immediately after dosing. Later, two of the remaining treated animals and a control goat were euthanized after a 30-day recovery period. Euthanized animals were necropsied and tissues were collected and prepared for histologic studies. Clinical signs in treated goats were transient and included depression and lethargy, mild hyperpnea and hyperthermia, arrhythmias, abundant salivation, vocalizations, expiratory dyspnea, jerky movements and head pressing. Two goats developed convulsions after day 3 of treatment. One animal developed more permanent behavioral changes as she became less dominant and aggressive. Histologic changes included mild hepatocellular vacuolation and degeneration, mild vacuolation and swelling of the proximal convoluted tubules of the kidneys and spongiosis of the white matter (status spongiosis) of the cerebral white tracts, internal capsule, cerebellar peduncles, spinal cord and peripheral nerves. In summary, sub-lethal cyanide intoxication in goats resulted in behavioral changes, and during the treatment period animals showed delayed signs of toxicity. Significant histologic lesions in goats were observed and need to be characterized further. Copyright © 2005 John Wiley & Sons, Ltd. [source] Dystonia Associated with pontomesencephalic lesions,MOVEMENT DISORDERS, Issue 2 2009Thomas J. Loher MD Abstract Secondary dystonia is well known subsequent to lesions of the basal ganglia or the thalamus. There is evidence that brainstem lesions may also be associated with dystonia, but little is known about pathoanatomical correlations. Here, we report on a series of four patients with acquired dystonia following brainstem lesions. There were no basal ganglia or thalamic lesions. Three patients suffered tegmental pontomesencephalic hemorrhage and one patient diffuse axonal injury secondary to severe craniocerebral trauma. Dystonia developed with a delay of 1 to 14 months, at a mean delay of 6 months. The patients' mean age at onset was 33 years (range 4,56 years). All patients presented with hemidystonia combined with cervical dystonia, and two patients had craniofacial dystonia in addition. Three patients had postural or kinetic tremors. Dystonia was persistent in three patients, and improved gradually in one. There was little response to medical treatment. One patient with hemidystonia combined with cervical dystonia improved after thalamotomy. Overall, the phenomenology of secondary dystonia due to pontomesencephalic lesions is similar to that caused by basal ganglia or thalamic lesions. Structures involved include the pontomesencephalic tegmentum and the superior cerebellar peduncles. Such lesions are often associated with fatal outcome. While delayed occurrence of severe brainstem dystonia appears to be rare, it is possible that mild manifestations of dystonia might be ignored or not be emphasized in the presence of other disabling deficits. © 2008 Movement Disorder Society [source] Brain structural damage in spinocerebellar ataxia type 2.MOVEMENT DISORDERS, Issue 6 2008A voxel-based morphometry study Abstract Voxel-based morphometry (VBM) enables an unbiased in-vivo whole-brain quantitative analysis of differences in gray matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) volumes. We assessed with VBM 20 spinocerebellar ataxia Type 2 (SCA2) patients with mild or moderate cerebellar deficit and 20 age and sex-matched healthy controls. SCA2 patients showed a significant (P < 0.05 corrected for multiple comparison) symmetric loss of GM in the cerebellar vermis and hemispheres sparing lobules I,II, Crus II,VII, and X, and of the WM in the peridentate region, middle cerebellar peduncles, dorsal pons, and cerebral peduncles. The CSF volume was increased in the posterior cranial fossa. No GM, WM or CSF volume changes were observed in the supratentorial compartment. A mild (P < 0.05, >0.01) correlation was observed between the GM and WM loss and severity of the neurological deficit. In SCA2 patients with mild to moderate cerebellar deficit, GM and WM volume loss and CSF volume increase are confined to the posterior cranial fossa. © 2008 Movement Disorder Society [source] | ||||||||||