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PubMed1981

A Golgi study on the globus pallidus of the mouse.

The globus pallidus (GP) of the mouse was studied by the rapid Golgi silver impregnation method. The GP was composed of large and medium-sized neurons. The large neurons had stellate cell bodies with a mean diameter of 25 micron by 28 micron and five to seven primary dendrites. The somata of the medium-sized neurons were spindle or fusiform in shape, measured 19 micron by 27 micron in average and emitted three to five primary dendrites. The large neurons were located mainly in the central part of the GP, whereas the medium-sized neurons were observed in the peripheral part of the GP. Some GP neurons extended their dendrites into the caudatoputamen complex, sublenticular region or internal capsule. The axons of the GP neurons were seen most frequently to course medially or mediocaudally and to enter the internal capsule or fiber bundles traversing the GP; they were rarely observed to run laterally and to travel into the caudatoputamen complex. Some axons of the GP neurons were also observed to emit intra- or extra-nuclear collaterals extending into the sublenticular region. Four groups of afferent fibers to the GP were observed; (1) fibers descending within the internal capsule or caudatoputamen complex to terminate or to give axon-collaterals to the GP; (2) fibers ascending within the internal capsule or fiber bundles traversing the GP to enter the GP from its medial aspects; (3) fibers traversing the internal capsule laterally to terminate in the GP; and (4) fibers running dorsally through the sublenticular region to terminate in the GP. In addition to these four groups of afferent fibers, terminal branches were seen to arise numerously from many fibers running through the GP.

Afferent Pathways↗
PubMed1981

A quantitative regional analysis of protein synthesis inhibition in the rat brain following localized injection of cycloheximide.

Previous work has shown that bilateral injection of as little as 10 microgram of cycloheximide (CHX) into the amygdala, but not into the internal capsule, caused a time-dependent disruption of long-term retention of passive avoidance training. Under these conditions, protein synthesis in the entire brain was inhibited by less than 10%. The present study was undertaken to quantify the resulting inhibition of protein synthesis in various brain regions (amygdala, internal capsule, caudate, cortex, hippocampus, thalamus, hypothalamus and the entire half brain). Rats were subcutaneously injected with L-[14C-methyl]methionine following unilateral administration of CHX via a cannula implanted in either the amygdala or the internal capsule. Regional inhibition of protein synthesis was determined by analysis of autoradiograms from different brain levels using an image analyzing computer to measure the optical densities of microscopic areas corresponding to discrete neuroanatomical structures. Regional patterns of inhibition were assessed: (a) after injection of different doses of CHX (10 or 20 microgram) into the amygdala; (b) after injection of 20 microgram of CHX into the amygdala or internal capsule; and (c) at different times (0.5, 3, 6 and 24 h) after injection of 20 microgram of CHX into the amygdala. Quantitative results are presented for the temporal and spatial patterns of protein synthesis inhibition caused by CHX injection. Since injection of CHX into the amygdala resulted in a profound inhibition of protein synthesis in both the amygdala and internal capsule while injection into the thermal capsule only caused a marked inhibition in the capsule itself, these results provide a possible explanation for our earlier observation that injection of CHX into the amygdala produced a retention deficit while injection into the adjacent internal capsule had no effect on memory function. These observations on protein synthesis inhibition support our earlier hypothesis that CHX injected into the amygdala might impair memory by virtue of its action on amygdaloid function rather than as a result of its effect on the brain as a whole.

Amygdala↗
PubMed2004

Morphological study of the perireticular nucleus in human fetal brains.

Abstract The perireticular nucleus consists of scattered neurons that are located in the internal capsule. The presence of perireticular neurons in the rat, ferret, cat and human has been described previously. Evidence suggests that the perireticular neurons in various species decrease in number with increasing gestation, but in humans this finding has not been supported by quantitative data. This study aimed to investigate (1) the morphology of the human fetal perireticular neurons, (2) the average number of perireticular neurons within the anterior and posterior crus of the internal capsule per unit area, and (3) the magnitude and the stage of neuronal loss in the human perireticular nucleus subsequent to maturation. Nissl-stained sections of the internal capsule of human fetal brains of 24, 26.5, 32, 35, 37 and 39 weeks of gestation showed a number of clearly distinguishable large perireticular and small microglia cells. A regular increase of both perireticular and microglial cells was observed up to 32 weeks of gestation, after which a dramatic reduction in the number of both perireticular and microglia cells was observed. The average number of perireticular and the microglia cells per unit area, located within the posterior crus, was more than in the anterior crus of the internal capsule. In the adult, no perireticular neurons were detected within the internal capsule. The results show that perireticular neurons are not restricted to the region lateral to the thalamus and medial to the globus pallidus (posterior crus) but are also present at the region lateral to the caudate nucleus and medial to the globus pallidus (anterior crus).

Adult↗
PubMed1997

Patients with stroke confined to basal ganglia have diminished response to rehabilitation efforts.

Prediction of the functional outcome for patients with stroke has depended on the severity of impairment, location of brain injury, age, and general medical condition. This study compared admission and discharge functional outcome (Functional Independence Measure, FIM) and deficit severity (Fugl-Meyer, F-M) scores in a retrospective study of patients with similar neurologic impairments: homonymous hemianopia, hemisensory loss, and hemiparesis. CT-verified stroke location was the independent variable: cortical (n = 11), basal ganglia and internal capsule (normal cortex and thalamus, n = 13), or combined (cortical, basal ganglia, and internal capsule, n = 22). By 3 months on average after stroke, all groups demonstrated significantly improved motor function as measured by F-M scores. Patients with cortical lesions had the least CT-imaged damage and the best outcome. Patients with combined lesions and more extensive brain injury had significantly higher FIM scores (P < 0.05) than patients with injury restricted to the basal ganglia/ internal capsule. Patients with basal ganglia/internal capsule injury were more likely to have hypotonia, flaccid paralysis, and persistently impaired balance and ambulation performance. While all patients had a comparable rehabilitation experience, these results suggest that patients with stroke confined to the basal ganglia and internal capsule benefited less from therapy. Isolated basal ganglia stroke may cause persistent corticothalamic-basal ganglia interactions that are dysfunctional and impede recovery.

Aged↗
PubMed1997

Analysis of pallidotomy lesion positions using three-dimensional reconstruction of pallidal lesions, the basal ganglia, and the optic tract.

OBJECTIVE: To assess the position of radiofrequency pallidotomy lesions placed using microelectrode stimulation and cellular recordings in relation to a stereotactically defined starting point. Radiofrequency lesion locations were also evaluated in relation to the putamen, posterior limb of the internal capsule, and optic tract. METHODS: Magnetic resonance images obtained from 23 patients with Parkinson's disease who underwent pallidotomy at the University of Kansas Medical Center were analyzed. Using computerized techniques, lesion positions in relation to the midcommissural point and a hypothetical starting point were determined. Data segmentation and three-dimensional reconstruction of pallidal lesions, the internal capsule, and the optic tract allowed assessment of lesion position in relation to internal anatomy. Clinical outcome of pallidotomy was assessed using both the Unified Parkinson's Disease Rating Scale and the Dementia Rating Scale. RESULTS: Pallidal lesions were usually placed anterior and dorsal to the stereotactically defined starting point. The position of pallidal lesions in the men were observed, in four trials, to be significantly more dorsal than the lesions in the women. The outer zone of the lesion was usually adjacent to the internal capsule and the putamen and relatively close to the optic tract. The inner zone of the lesion was usually several millimeters removed from anatomic boundaries of the putamen, internal capsule, and optic tract. Patients achieved favorable outcomes, with reduced dyskinesias and "off" time and improvement of their Parkinsonian symptoms, as evidenced by clinical assessment, the Unified Parkinson's Disease Rating Scale, and the Dementia Rating Scale. CONCLUSION: Microelectrode stimulation and cellular recordings usually led to a final pallidotomy lesion position that deviated from the stereotactically defined starting point. The pallidotomy lesions in the men were observed to be more dorsal than the lesions in the women. Clinical outcomes were not correlated with either lesion location relative to the starting point or distances between the pallidal lesion and the putamen, internal capsule, or optic tract. Kinesthetically responsive cells may be localized generally more anterior and dorsal to the starting point (within the globus pallidus) and may be grouped variably from patient to patient in relation to other basal ganglia structures. Although the primary lesion site is most likely within the sensorimotor region of the globus pallidus internus, the more dorsal locations of responsive cell groups may indicate that some lesion sites may be localized within the globus pallidus externus.

Aged↗
PubMed2001

[Cerebral blood flow disturbances after anterior choroidal artery infarcts. Anatomical and functional correlates].

We have investigated the cortical and subcortical regional cerebral blood flow (rCBF) disorders resulting from infarcts of the anterior choroidal artery (AChA), and correlations with the severity of lesions, the physical and cognitive deficits, and the functional impairment. Eighteen patients presenting with recent anterior choroidal artery infarct without any other brain injury were examined at the secondary phase post-stroke using the single photon emission computed tomography technique and 133 Xenon inhalation. The rCBF and asymmetry indexes (AI) were calculated for 12 symmetrical hemispheric areas, and the cerebellum. The AI values were compared with those of 24 control subjects. The severity of the lesions was evaluated from CT scans or MRI. The neurological status (Orgogozo scale, walking disorders, MMSE, attention impairment, aphasia) and disability (functional independance measure: FIM) were assessed for each patient at the same time period. The relationships between rCBF disorders and brain lesions, and between the results of clinical investigations and rCBF disorders and brain lesions were assessed by linear regression analyses (stepwise variable selections, p=0.05). The AI values were significantly increased in the cerebral hemispheres, and this was most severe in the internal capsule (direct effect of the lesion) and the dorsolateral hemispheric cortex (diaschisis). Individual evaluations showed that AI were significantly increased in 13 patients in at least one ROI of the cerebral hemispheres, and in 3 patients in the internal capsule. Stepwise variable selections revealed that AI were best explained by the severity of the lesions in the internal capsule and the internal temporal area. The AI of the external temporal area and the internal capsule also helped explain the clinical (physical and cognitive) deficits. Thus, AChA infarcts may have relatively large effects on the central part of the lateral and dorsal cortex of the ipsilateral hemisphere. Subcortical and cortical consequences both contribute to explain the motor and cognitive deficits and disability.

Aged↗
PubMed1994

Differential expression patterns of mRNAs for members of the fibroblast growth factor receptor family, FGFR-1-FGFR-4, in rat brain.

We have examined the region-specific expression of mRNAs for four members of rat FGF receptor family, FGFR-1, FGFR-2 FGFR-3, and FGFR-4, in rat brain by in situ hybridization. The FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but differentially in the brain. However, the FGFR-4 mRNA was not expressed in the brain. The FGFR-1 mRNA was strongly expressed in several regions including the hippocampus, cerebellum, and pedunculopotine tegmental nucleus. The FGFR-2 mRNA expression was high in the choroid plexus, and moderate in the fiber-rich regions (the corpus callosum, external capsule, and internal capsule) and the olfactory bulb. The FGFR-3 mRNA was expressed diffusely in the brain. We have also examined the cellular localization of these mRNAs in the brain. Although the FGFR-1 mRNA was expressed preferentially in neurons, the FGFR-2 and FGFR-3 mRNAs were expressed preferentially in glial cells. The present findings that the FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but with region- and cell-specificity in the brain indicate that these receptors have different roles in the brain.

Amino Acid Sequence↗
PubMed1999

Excitatory synaptic inputs to pyramidal neurons of the lateral amygdala.

Whole-cell patch clamp recordings were made from pyramidal neurons in the rat lateral amygdala (LA). Synaptic currents were evoked by stimulating in either the external capsule (ec), internal capsule (ic) or basolateral nucleus (BLA). Stimulation of either the ic, ec or BLA evoked a glutamatergic excitatory synaptic current (EPSC) which was mediated by both non-NMDA and NMDA (N-methyl-d-aspartic acid) receptors. The ratio of the amplitude of the NMDA receptor-mediated component measured at +40 mV to the amplitude of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) component measured at -60 mV was similar regardless of whether EPSCs were evoked in the ec, ic or BLA. At resting membrane potentials, excitatory synaptic potentials evoked from either the ec or putative thalamic inputs were unaffected by application of the NMDA receptor antagonist APV. Spontaneous glutamatergic currents had two components to their decay phase. The slow component was selectively blocked by the NMDA receptor antagonist D-APV, indicating that AMPA and NMDA receptors are colocalized in spiny neurons. We conclude that pyramidal cells of the LA receive convergent inputs from the cortex, thalamus and basal nuclei. At all inputs, both AMPA/kainate and NMDA-type receptors are active and colocalized in the postsynaptic density.

Amygdala↗
PubMed1993

A brain-specific protein p25 is localized and associated with oligodendrocytes, neuropil, and fiber-like structures of the CA3 hippocampal region in the rat brain.

Developmental expression and cellular localization of a novel brain-specific 25-kDa protein (p25), a substrate of tau protein kinase II, were investigated in the rat brain using polyclonal antibodies raised against peptides synthesized based on the p25 amino acid sequence. By western immunoblotting, p25 was found to be expressed only slightly in the embryonic period; the expression increased from 11 days up to 5 weeks of age, and continued to increase gradually until 1-2 years of age. Immunohistochemistry revealed distinct staining of glial cells in most regions of the central nervous system in the adult rat brain. These positively immunostained cells were especially abundant in the white matter, such as the corpus callosum, cingulum, external capsule, and internal capsule. The glial cells were identified as oligodendrocytes, and the nuclei of the cells remained unstained. Whereas the neuropil in most parts of the brain was immunostained less intensely than glias, the neuropil in the first and second layers of the cerebral cortex and the dentate gyrus was relatively strongly stained. Fiber-like structures were also stained in the CA3 region of hippocampus.

Aging↗
PubMed1993

Motor recovery following capsular stroke. Role of descending pathways from multiple motor areas.

The functional anatomy of motor recovery was studied by assessing motor function quantitatively in 23 patients following capsular or striatocapsular stroke. While selective basal ganglia lesions (caudate and/or putamen exclusively) did not affect voluntary movements of the extremities, lesions of the anterior (plus caudate/putamen) or posterior limb of the internal capsule led to an initially severe motor impairment followed by excellent recovery, hand function included. In contrast, lesions of the posterior limb of the internal capsule in combination with damage to lateral thalamus compromised motor outcome. In experimental tracing of the topography of the internal capsule in macaque monkeys, we found axons of primary motor cortex passing through the middle third of the posterior limb of the internal capsule. Axons of premotor cortex (dorsolateral and post-arcuate area 6) passed through the capsular genu, and those of supplementary motor area (mesial area 6) through the anterior limb. Small capsular lesion can therefore disrupt the output of functionally and anatomically distinct motor areas selectively. The clinically similar motor deficits with a similar course of functional restitution following disruption of these different descending motor pathways indicate a parallel operation of cortical motor areas. They may have the further capability of substituting each other functionally in the process of recovery from hemiparesis.

Adult↗
PubMed1994

Development of the thalamic reticular nucleus in ferrets with special reference to the perigeniculate and perireticular cell groups.

This study describes the development of the ferret thalamic reticular nucleus from Nissl-stained and from parvalbumin-immunostained sections. From early stages [embryonic day (E) 23-E25], there is a large group of ventral thalamic cells which lies between the dorsal thalamus and the primordial internal capsule. This group of cells, the primordial reticular nucleus, gives rise to the main body of the reticular nucleus, the perigeniculate nucleus and the perireticular nucleus. In the reticular nucleus, there are two waves of parvalbumin expression during development. The first wave begins prenatally in small cells which are seen rarely after birth. Their fate is not clear: they may have lost immunoreactivity, migrated elsewhere, or died. At the end of the first wave, a second wave begins in a distinct group of larger ovoid reticular cells, which appear to remain into adulthood. At about birth, the dorsocaudal pole of the reticular nucleus first forms the perigeniculate nucleus. During this developmental stage, cells which make up the reticular and perigeniculate nuclei are the only parvalbumin-immunostained structures in the thalamus. Thus, rather than develop from the dorsal thalamus, the perigeniculate nucleus seems to have its origins in the ventral thalamus together with the reticular nucleus. During development, the reticular nucleus is associated closely with a large mass of cells located in the internal capsule, called the perireticular nucleus. Later, the perireticular nucleus is dramatically reduced in size: that is, there is a large reduction in the number of perireticular cells seen per section and in the extent of the nucleus across the internal capsule. There are two cytoarchitectonically distinct groups of perireticular cells. One group of cells, called the large-celled perireticular zone (LPR), enters the internal capsule from early prenatal development (E25). Many of these cells reach the globus pallidus and extend as far as the cortical subplate zone. The LPR together with the subplate form an extensive neuronal network in the white matter during early development, which disappears later in development (about postnatal day 20). The second group of perireticular cells is made up of smaller cells and is called the small-celled perireticular zone (SPR). These small cells enter the internal capsule from the reticular nucleus just prior to birth. Many of the cells in the SPR remain in the adult.

Aging↗
PubMed2000

The pyramidal tract in congenital hemiparesis: relationship between morphology and function in periventricular lesions.

Three-dimensional MRI data sets were obtained from 12 young adult patients with congenital spastic hemiparesis caused by unilateral periventricular white matter lesions. The impact of these lesions on corticospinal projections to the upper and lower extremities was assessed on reconstructed semi-coronal planes following anatomical landmarks of somatotopic organization in the precentral gyrus and in the internal capsule: a more anterior plane running through the hand-knob of the precentral gyrus and the anterior portion of the posterior limb of the internal capsule representing projections to the upper extremity, and a more posterior plane running through the top of the precentral gyrus and the middle portion of the posterior limb of the internal capsule representing projections to the lower extremity. In addition, the total lesion extent was determined volumetrically, and Wallerian degeneration was assessed qualitatively in the internal capsule and quantitatively by measuring brainstem asymmetry. We found a strong correlation between motor dysfunction of the upper and lower limb and the lateral extent of the periventricular lesion measured on the respective semi-coronal planes. The total lesion volume and the degree of Wallerian degeneration correlated less strongly, both reaching statistical significance only with motor impairment of the hand.

Adolescent↗
PubMedDate not supplied

Theoretical prediction of the hemodynamic performance of slow resorbing polyester protein impregnated arterial prostheses after implantation: a plea for fast resorption of the coating.

The clinical literature cites cases where slow, incomplete, or nonuniform protein resorption from protein impregnated arterial prostheses produces undesirable localized internal capsule proliferation leading to a significant reduction of the internal diameter of the prosthesis. In an attempt to describe the hemodynamic response to this phenomenon, the blood flow in such stenotic regions was simulated and characterized numerically using FIDAP computational fluid dynamics software to determine the Navier-Stokes and continuity equations for simple channel flow. To simulate various stages of internal capsule development, numeric computations were made in an idealized tubular expansion at stenosis ratios ranging from 0.9 to 0.5 and stenosis length ratios from 10 to 40. The results indicated that a triangular annular ring vortex was formed immediately distal to the stenosis at all Reynolds numbers (Re) studied. The size of the vortex increased almost linearly with the Reynolds number. The pressure drop through the stenosis was affected by blood flow rate, severity, and stenosis length. When the stenosis ratio was low, the pressure drop through the stenosis increased gradually and almost linearly with blood flow rate. In a severe stenosis, the pressure drop was no longer a linear function of flow rate, but increased significantly with increasing flow rate. In conclusion, satisfactory healing of the internal capsule requires fast resorption of any impregnated protein. If the resorption is slow, incomplete, or nonuniform, there is a tendency for the lumen to narrow, causing stenosis, an increased pressure drop through the narrowed graft and disturbed flow distal to the stenosis. This phenomenon therefore constitutes a major limitation for using this type of graft in small diameter arterial reconstruction.

Absorbable Implants↗
PubMed2004

Hand coordination following capsular stroke.

Motor outcome following stroke of the internal capsule is variable and its determinants are poorly understood. While many patients fully regain their abilities, recovery of motor functions remains incomplete in others. We analysed functional motor tasks of the upper limb to determine the pattern of focal disability after a small infarct of the internal capsule ('pure motor stroke') in the chronic stage (mean 2.4 years after stroke) with kinematic recordings of a reaching-to-grasp movement, with a quantitative analysis of the precision grip, and with clinical rating scales. The location of the lesions within the posterior limb of the internal capsule (PLIC) in 18 patients was determined from neuroimages obtained in the acute stage (5-20 days after the insult). Involvement of the PLIC was assessed at the level of the basal ganglia, approximately 8 mm above the anterior commissure-posterior commissure level. The distance between the posterior edge of the internal capsule and the centre of gravity of the lesion was determined. Chronic disabilities affected dextrous movements, while paresis was mild and sensitivity for light touch or passive finger flexion was almost normal. For both the reaching-to-grasp movement and the precision grip paradigm, the slowness of movement or force development was confined to the phases when grip formation and stabilization occur, while the onset of hand transport and of the vertical lifting force were not delayed. Grip forces were increased. We observed a close correlation between posterior location within the PLIC and the altered measures of timing and precision grip force. The more posterior the acute lesion was located within the PLIC, the more pronounced were the chronic motor deficits, as seen both in the quantitative measures and in the rating scales. The present study demonstrates for the first time that the amount and quality of chronic motor deficits of dextrous movements are related to a simple measure drawn from routine neuroimaging in the acute stage in patients with capsular stroke. The poor motor outcome in lesions involving the most posterior parts of the PLIC could be due to the condensed organization of corticofugal projections and the density of pyramidal fibres from the primary motor cortex in this subsector. Even small infarcts of this strategic area can disrupt many of the projections from the motor cortices and could thereby limit recovery strategies between homolateral motor representations.

Adult↗
PubMed1994

Isolated hemiataxia after supratentorial brain infarction.

Acute isolated hemiataxia is in most cases due to infratentorial (cerebellar) stroke. It has only twice been described in supratentorial stroke--namely, after thalamic infarction and a capsular haemorrhage. Three patients with isolated hemiataxia after a supratentorial brain infarct are described. These patients were seen in a period of five years during which 899 patients with a first supratentorial brain infarct were registered. Clinically the hemiataxia was of the cerebellar type. In two patients, CT and MRI showed a small, deep (lacunar) infarct restricted to the posterior limb of the internal capsule, a site not previously reported in isolated hemiataxia. The third patient had a small, deep (lacunar) infarct in the thalamus extending into the adjacent posterior limb of the internal capsule. Isolated hemiataxia after a supratentorial brain infarct is a very rare clinical stroke syndrome. The cerebellar type hemiataxia was most likely caused by interruption of the cerebellar pathways at the level of the internal capsule. Our cases confirm prior observations that the cerebellar pathways run through the posterior part of the posterior limb of the internal capsule separately from the motor and sensory pathways.

Acute Disease↗
PubMed1997

[An autopsy case of amyotrophic lateral screlosis (ALS): magnetic resonance imaging and pathological findings of the pyramidal tract].

A 59-year-old woman was diagnosed as amyotrophic lateral screlosis (ALS) on the basis of neurological and electromyographical findings, and died after about 4 years course. Magnetic resonance imaging (MRI) on coronal planes through the internal capsule revealed high signal area almost limited to the pyramidal tract; the high signal area was more restricted in proton weighted imaging than in T2 weighted imaging. Histological lesion of the precentral gyrus was slight, while loss of myelinated fibers in the posterior limb of the internal capsule was remarkable. Extent of the pathological lesion in the posterior limb of the internal capsule well corresponded to the high signal area in proton weighted imaging. Comparison of the pyramidal tract pathology in the corona radiata and the internal capsule in Klüver-Barrera preparations with the MRI findings obtained 2 years and 8 months before the autopsy suggests us that the T2 weighted imaging of ALS brains may detect involvement of the pyramidal tract as early as or even earlier than histological changes become manifest.

Amyotrophic Lateral Sclerosis↗
PubMed2003

Diffusion tensor imaging detects corticospinal tract involvement at multiple levels in amyotrophic lateral sclerosis.

BACKGROUND: Histopathological studies of amyotrophic lateral sclerosis (ALS) are of end stage disease. Diffusion tensor imaging (DTI) provides the opportunity to investigate indirectly corticospinal tract pathology of ALS in vivo. METHODS: DTI was used to study the water diffusion characteristics of the corticospinal tracts in 21 patients with ALS and 14 normal controls. The authors measured the fractional anisotropy (FA) and mean diffusivity (MD) along the pyramidal tracts from the internal capsules down to the pyramids. A mixed model regression analysis was used to compare FA and MD between the ALS and control groups. RESULTS: FA showed a downward linear trend from the cerebral peduncles to the pyramids and was lower in the ALS group than controls at multiple levels of the corticospinal tract. At the internal capsules, FA was higher on the right. MD showed an upward trend, progressing caudally from the internal capsules to the pyramids. MD was higher at the level of the internal capsule in the ALS group, but caudally this difference was not maintained. No correlations were found between clinical markers of disability and water diffusion indices. CONCLUSIONS: These findings provide insights into the pathological processes of ALS. Differences in diffusion characteristics at different anatomical levels may relate to underlying tract architecture or the distribution of pathological damage in ALS. Further development may permit monitoring of progression and treatment of disease.

Adult↗
PubMed1992

Cerebral white matter and cognition in hydrocephalic children.

Although children with hydrocephalus frequently show poor development of nonverbal cognitive skills relative to verbal skills, little is known about the neuropathologic correlates of these discrepancies. In this study, cerebral white-matter structures and lateral ventricles were measured from the magnetic resonance images of age-matched children with meningomyelocele, meningocele, and aqueductal stenosis and normal subjects. The volume of each lateral ventricle and the cross-sectional area of the corpus callosum and internal capsules were correlated with concurrent measures of verbal and nonverbal cognitive skills. The corpus callosum in the meningomyelocele and aqueductal stenosis groups was smaller. The lateral ventricles were larger, and the internal capsules were smaller, in all patient groups than in normal subjects. There were no differences in the size of the centra semiovale. Although verbal and nonverbal measures correlated positively with the size of the corpus callosum, the correlation was higher for nonverbal measures. Nonverbal measures correlated with the right, but not the left, lateral ventricle and with the area of the right and left internal capsules. Verbal measures correlated with the left, but not right, lateral ventricle and with the left, but not right, internal capsule. These results show a relationship between the corpus callosum and cognitive skills that is also influenced by hydrocephalus-related changes in the lateral ventricles and other cerebral white-matter tracts.

Adolescent↗