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PubMedDate not supplied

[Blood supply of the internal capsule and basal nuclei].

The internal capsule and basal nuclei are supplied by perforating branches of the anterior cerebral artery (ACA), Heubner's artery, middle cerebral artery (MCA), internal carotid artery (ICA) and anterior choroidal artery (AChA). Some of the mentioned perforators vascularize both the internal capsule and basal nuclei, while some of them also perfuse the adjacent brain structures. Dorsal part of the anterior limb, knee and posterior limb of the internal capsule are commonly supplied by lateral MCA perforators. The intermediate part of the anterior limb is perfused by medial MCA perforators, while its ventral part is nourished by ACA perforators and Heubner's artery. The intermediate part of the knee is supplied by medial MCA perforators, while its ventral part is mostly vascularized by ICA and proximal AChA perforators. The intermediate part of the posterior limb is perfused by medial MCA perforators anteriorly and the proximal AChA perforators posteriorly. The ventral part is supplied by AChA perforators. The retrolenticular and sublenticular portions of the internal capsule are mainly nourished by distal AChA perforators. The caudate nucleus is supplied by perforators of the ACA, MCA and AChA, as well as by branches of the lateral posterior choroidal artery. Most of the putamen is vascularized by MCA perforators, and smaller parts by ACA and AChA perforators. The lateral segment of the globus pallidus is perfused by MCA perforators and partially by Heubner's artery and ACA, while its medial segment is supplied by ICA and AChA perforators. The ACA perforators, that most often originate from the initial 5.9 mm of the A1 segment, range in number from 1 to 5 (mean, 2.2) and in diameter between 80 pm and 710 pm (average, 295 microm). Heubner's artery, which most often arises close to the anterior communicating artery, can be singular (72.5%), double (23%) or triple (4.5%). It varies in diameter from 190 microm to 1,600 pm (average, 750 microm) and in length between 11 mm and 36 mm (mean, 22.4 mm). The MCA perforators, that most frequently originate from M1 segment (90.7%) and leptomeningeal branches (62.6%), range in number between 2 and 13 (mean, 8.1) and in diameter from 80 microm to 1,300 microm (mean, 520 microm). Many perforators arise as individual vessels, and some of them with common trunks (70.8%). Medial and lateral group of these perforators can be distinguished. The ICA perforators, which more often arise close to the AChA originating site (35.4%) than from the ICA bifurcation point (10.4%), vary in number from 1 to 5 (average, 3) and in diameter between 70 microm and 500 microm (mean, 236 microm). The AChA perforators that originate from its cisternal segment, range in number from 2 to 9 (mean, 4.5) and in diameter from 90 microm to 600 pm (mean, 325 microm).

Adult↗
PubMed1998

Development of glia and blood vessels in the internal capsule of rats.

We have explored two aspects of internal capsule development that have not been described previously, namely, the development of glia and of blood vessels. To these ends, we used antibodies to glial fibrillary acidic protein (GFAP) and to vimentin (to identify astrocytes and to radial glia) and Griffonia simplicifolia (lectin; to identify microglia and blood vessels). Further, we made intracardiac injections of Evans Blue to examine the permeability of this dye in the vessels of the internal capsule during neonatal development. Our results show that large numbers of radial glia, astrocytes and microglia are not labelled with these markers in the white matter of the internal capsule until about birth; very few are labelled earlier, during the critical stages of corticofugal and corticopetal axonal ingrowth (E15-E20). The large glial labelling in the internal capsule at birth is accompanied by a dense vascular innervation of the capsule; as with the glia, very few labelled patent vessels are seen earlier. After intracardiac injections of Evans Blue, we find that the blood vessels of the internal capsule are not particularly permeable to Evans Blue. At each age examined (P0, P5, P15), blood vessels are outlined very clearly and there is no diffuse haze of fluorescence within the extracellular space, which is indicative of a leaky vessel. There are three striking differences between the glial environment of the internal capsule and that of the adjacent thalamus. First, the internal capsule is never rich with radial glial fibres (vimentin- and GFAP-immunoreactive) during development (except at P0), whereas the thalamus has many radial fibres from very early development (E15-E17). Second, astrocytes (vimentin- and GFAP-immunoreactive) first become apparent in the internal capsule (E20-P0) well before they do in the thalamus (P15). Third, the internal capsule houses a large transient population of amoeboid microglia (P0-P22), whereas the thalamus does not; only ramified microglia are seen in the thalamus. In summary, our results indicate that all three types of glia in the internal capsule are associated closely with the vasculature, suggesting they may play a role in the development of the blood-brain barrier among the vessels in this white matter region of the forebrain.

Animals↗
PubMed1996

Ill-defined focal low attenuation in the posterior internal capsule: a normal CT finding.

Although many pathological changes in the internal capsule may lead to neurological deficits, we often encounter ill-defined focal low attenuation in the posterior limb of the internal capsule (PIC) on CT in patients with no neurological disturbance. Brain CT studies of 141 patients without neurological deficits were reviewed to investigate the position of the focal low attenuation by analysis of a profile density curve. Nine patients with lacunar infarcts only within the posterior internal capsule were also studied. The focal low attenuation areas were ill-defined and bilaterally symmetrical, without mass effect. They were seen consistently within the posterior limb of the posterior internal capsule. Correlation between the distribution of these foci and the position of lacunar infarcts in the posterior internal capsule in nine patients with neurological deficits suggests that they may be related to the corticospinal tract.

Adult↗
PubMed2002

Responses of diencephalic nociceptive neurones to orofacial stimuli and effects of internal capsule stimulation in the rat.

The effect of conditioning stimulation of the internal capsule on nociceptive neurones in the rat diencephalon was investigated. The animals were anaesthetised with N(2)O/O(2) (2:1) and 0.5% halothane, and immobilised with pancuronium bromide. Nociceptive neurones responding to noxious stimulation of the face and oral structures were recorded in the ventral posteromedial nucleus, posterior group and zona incerta. These neurones were classified into wide dynamic range and nociceptive-specific types. Functional segregation of these nociceptive neurones was not apparent within the nucleus or between nuclei. A test stimulus with a single rectangular pulse (5-70 V) was applied to the centre of the receptive field; the nociceptive neurones exhibited short- and/or long-latency responses. Both responses in about 45% of the nociceptive neurones were inhibited by conditioning stimuli to the contralateral internal capsule with trains of 33 pulses (300 microA) at 330 Hz. The percent inhibitory effects on the nociceptive neurones of each area were 68.0+/-14.8% (n = 6) in the ventral posteromedial nucleus, 72.8+/-12.4% (n = 4) in the posterior group and 61.5+/-7.5% (n = 4) in the zona incerta. Effective sites for conditioning stimulation were concentrated in the lateral side of the internal capsule, through which the corticofugal fibres from the somatosensory cortex pass. These findings suggest that the transmission of nociceptive information to the diencephalon is modulated by stimulation of the internal capsule at the level of the trigeminal sensory complex in the brainstem. They might provide a novel way to elucidate the neurophysiological basis for antinociception by stimulation of the internal capsule observed in clinical studies.

Animals↗
PubMed1991

[Relationship between motor disturbance and involvement of internal capsule in hypertensive thalamic hemorrhage].

We treated a consecutive series of 309 patients with hypertensive thalamic hemorrhage from April 1981 to December 1987. In 99 cases of involvement of the internal capsule, the relationship between the extent of destruction of the internal capsule and motor disturbance was clinically investigated and discussed. First, these 99 cases were classified into three groups on the basis of the location of the hematoma in the internal capsule on the CT image. All the cases were confined to the anterior, middle and posterior portions of the posterior limb of the internal capsule. The correlation between hematoma extension and the severity of motor weakness, its improvement nd prognosis were discussed. The severity of motor weakness was found not to be related to hematoma extension. On the other hand, the prognosis was frequently poor when the hematoma was located at the posterior portion within the posterior limb of the internal capsule. In hypertensive thalamic hemorrhage, there seemed to be a narrow and significant area within the posterior limb of the internal capsule which determined morbidity. And, as a matter of course, the nearer the hematoma was located to the border between the middle and posterior portions, the worse the outcome was. Cases treated by aspiration surgery were evaluated to investigate the utility of aspiration surgery for thalamic hemorrhage. (Special attention was given to the ADL of those cases with severe motor weakness.) When the hematoma was located at the posterior portion of the posterior limb of the internal capsule, the percentage of patients with good outcome was significantly higher in the aspirated group than in the medical group (p less than 0.05).

Brain↗
PubMed2005

The usefulness of fractional anisotropy maps in localization of lacunar infarctions in striatum, internal capsule and thalamus.

We aimed in this study to assess the clinical usefulness of fractional anisotropy (FA) maps in the evaluation of lacunar infarctions in striatum, internal capsule and thalamus. We retrospectively reviewed 28 patients (18 men, 10 women; mean age 63 years) who had acute lacunar infarction in striatum, internal capsule and thalamus on diffusion weighted MR imaging (DWI). Fractional anisotropy (FA) maps were generated in addition to conventional T2 weighted images (T2WI) and trace maps of DWI. Two radiologists reviewed the location of infarcts in combination with and without FA maps. Exact location of infarction was determined by FA maps, i.e. on the white band of internal capsule or outside the internal capsule. Accuracy and inter-observer agreement on determination of the location of infarction was evaluated. Accuracy of infarct localization by T2WI-DWI only was varied from 72 to 91% according to the observers. Inter-observer agreement value was moderate (Kappa=0.446), when images were interpreted by T2WI-DWI only. Clinical manifestation of each lesions were varied, but sensory motor stroke was mainly observed in thalamic lesion (50%), while pure motor hemiparesis was predominant in the case of infarct involving internal capsule, corona radiata (91%) and basal ganglia (83%). The FA map is useful in the evaluation of lacunar lesions in striatum, internal capsule and thalamus. Clinical presentation varies according to the exact location of lacunar infarctions, and more accurate diagnosis can be made by FA maps as well as conventional T2-weighted image and DWI.

Acute Disease↗
PubMed1983

Cortical KCl reinstates forelimb placing following damage to the internal capsule.

Following unilateral damage to the internal capsule, rats failed to use the contralateral forelimb during tests of contact, chin, and visual placing reactions. Infusion of potassium chloride onto the sensorimotor cortex contralateral to the lesion reinstated placing in the impaired limb and abolished placing in the normal limb. As the drug dissipated, placing in the impaired limb gradually deteriorated, while placing in the normal limb returned. In contrast, potassium chloride applied to the ipsilateral cortex did not reinstate placing. These findings suggest that the loss of forelimb placing following lesions of the internal capsule is due, at least in part, to tonic inhibition from the cortex contralateral to the lesion.

Animals↗
PubMed1988

Localisation of the corticospinal fibres in the internal capsule in man.

The myelogenetic development of the corticospinal fibres in the internal capsule was studied using eight brains of the Yakovlev Collection and two brains of the collection in Hannover Medical School. The myelin sheaths of the corticospinal fibres stained by the Loyez method can best be seen in the third postnatal month. During their course through the internal capsule their relative position changes. In the superior portion of the internal capsule, at the level of the interventricular foramen, the pyramidal tract is located in the middle of the posterior limb and in the inferior portion, at the level of the subthalamic nucleus and metathalamus, in the posterior third of the posterior limb. The classical concept of the localisation of the pyramidal tract has, therefore, to be revised for the inferior portion of the internal capsule. The result of this study confirms those of stereotactic, neuropathological and macroscopic observations and underlines the importance of the Yakovlev Collection for the neurosciences.

Child↗
PubMed1997

Central motor conduction studies in internal capsule and corona radiata infarction.

Clinical and evoked-potential studies in internal capsule and corona radiata infarction are lacking. We report the results of a clinical and central motor conduction time (CMCT) study in 16 patients with internal capsule and 17 with computed tomography (CT)-proven corona radiata infarction. Patients's outcome was defined at the end of 3 months on the basis of the Barthel Index score. Four patients with type A capsular infarction (middle third of posterior limb of internal capsule) all had severe weakness, while 2 also had persistently unrecordable CMCT and poor outcome. Twelve patients with type B internal capsular infarction (genu, anterior limb, anterior or posterior third of posterior limb) had a milder degree of weakness, and CMCT was recordable in 9. At 3 months' follow-up, however, CMCT was recordable in all 12 patients. All of these patients had a partial (n = 4) or complete (n = 5) recovery. Thirteen patients with type A corona radiata infarction (middle third of corona radiata) had more pronounced weakness, and CMCT was unrecordable in all of these patients except 1 on initial examination. Follow-up after 3 months was possible in 8 patients, and CMCT became recordable in 3. One of these patients had complete, 3 partial, and 4 poor recovery. In type B corona radiata infarction (anterior or posterior third of corona radiata), the clinical signs and CMCT did not follow a regular pattern. Clinical and CMCT abnormalities in internal capsular infarction followed a more predictable pattern compared with those in corona radiata infarction. A less predictable pattern of weakness and CMCT change in corona radiata infarction may be attributed to a less definite organisation of motor pathways compared with the internal capsule.

Adult↗
PubMed2005

The internal capsule in neonatal imaging.

The internal capsule is highly visible on conventional magnetic resonance imaging (MRI). It is myelinating rapidly at term, and the time course of its maturation is well known. It carries the major motor and sensory pathways to and from the cortex and the spinal cord. Additionally, fibres from the thalamus pass through it connecting to most regions of the cortex. It is therefore of vital importance, and damage to it has severe consequences. Its abnormal appearance on conventional MRI is a good predictor of an abnormal motor outcome in different clinical situations encountered in perinatal medicine. Its normal appearance on conventional MR images at term age is usually associated with a relatively normal motor outcome. More recently, diffusion-weighted and diffusion tensor imaging have allowed a much more sophisticated assessment of its maturation and connectivity; this has already led to a better understanding of how its development is affected by preterm birth and by hypoxic-ischaemic brain injury. Future studies will assess the relevance of these findings not only for motor outcome but also for cognitive, visual and sensory abilities.

Cerebral Infarction↗
PubMed2006

Reduced anterior internal capsule and thalamic volumes in first-episode psychosis.

BACKGROUND: The thalamus is the gateway for sensory and motor information en route to the cortex. Information is processed via thalamocortical and corticothalamic pathways coursing through the internal capsules. In this study, we investigated the relationship between the anterior limb of the internal capsule, posterior limb of the internal capsule, and thalamus in first-episode psychosis (FEP). METHODS: Twenty-nine FEP subjects (26 DSM-IV schizophrenia, 2 schizoaffective disorder, 1 psychosis not otherwise specified) and 22 healthy volunteers participated in this study. Anterior limb of the internal capsule (AIC), posterior limb of the internal capsule (PIC), and the thalamus volumes were manually determined from MRI scans. RESULTS: FEP subjects had reduced AIC volumes (F(1,45)=6.18, p=0.017) and thalamic volumes (F(1,45)=8.00, p=0.007) compared to healthy volunteers. PIC volumes did not differ. Significant correlations between AIC volumes and thalamic volumes were observed in subjects with FEP, but not in healthy volunteers. Negative relationships between thalamic volumes and symptom severity were also observed. CONCLUSIONS: The AIC and thalamic volumes were reduced in subjects with FEP compared to healthy volunteers. Abnormalities in thalamocortical and orticothalamic pathways may contribute to functional disruption of neural circuits in psychosis.

Adolescent↗
PubMedDate not supplied

Memory deficits following internal capsule lesions in rats and their improvement by L-6-ketopiperidine-2-carbonyl-L-leucyl-L-proline amide (RGH-2202), a thyrotropin-releasing hormone analogue.

A memory deficit model has been developed following bilateral internal capsule lesions in rats. During 12-49 days after internal capsule lesions, the rats showed a marked impairment of active avoidance acquisition in a step-through apparatus, while they exhibited no observable change in native behaviors, except a slight increase in exploratory activity. A passive avoidance task in the same apparatus was also impaired in internal capsule lesioned rats when examined after one-trial training, though the task was gradually acquired by repeated trainings. Moreover, the retention of both the active and passive avoidance responses in well-trained rats deteriorated after internal capsule lesions. On the other hand, internal capsule-lesioned rats did not perform any worse than sham-operated rats in a T-maze spontaneous alternation behavior and in a habituation response to a novel environment. In the frontal cortex and striatum of internal capsule-lesioned rats, there was a significant decrease of dopamine, serotonin and their metabolites, but no change of acetylcholine levels. The acquisition deficit of active avoidance in internal capsule-lesioned rats was improved by thyrotropin-releasing hormone (TRH, 10 mg/kg, i.p.) and L-6-ketopiperidine-2-carbonyl-L-leucyl-L-proline amide (RGH-2202, 10 mg/kg, i.p., 0.2 and 1 mg/kg i.v.), but not by physostigmine sulfate (0.2 mg/kg, i.p.). These results indicate that bilateral internal capsule lesions in rats induce long-term memory deficits which are paralleled with a decrease of the contents of monoamines and their metabolites and improved by TRH and RGH-2202.

Animals↗
PubMed1999

Connections between cells of the internal capsule, thalamus, and cerebral cortex in embryonic rat.

The aim of our study is to understand the development of the earliest connections in the mammalian pallium by documenting the distribution of cells and fibres labelled from the dorsal and ventral thalamus, internal capsule, perirhinal, and dorsal cortex during the period between embryonic day (E) 14 and 17 by using carbocyanine dye tracing in fixed embryonic rat brains. Dye placed in the thalamus of E14 brains backlabels cells in the thalamic reticular nucleus and within the primitive internal capsule. Both anterograde and retrograde tracing confirmed that the first corticofugal projections reach the internal capsule by E14. At E15-E16, after the first cortical plate cells have migrated into the lateral cortex, some cells of the cortical plate and subplate and marginal zone, are backlabelled from the internal capsule, but still not from the dorsal thalamus, even with very long incubation periods. Crystal placement into the perirhinal cortex at E14-E15 labels numerous cells within the internal capsule, whereas no such cells are revealed from dorsal cerebral cortex until E17, suggesting that internal capsule cells establish early connections with the perirhinal and ventral but not dorsal cortex. We propose that the growth of axons from cortex to dorsal thalamus is delayed in two regions: first from E14-E15 at the lateral entrance of the internal capsule and then, from E16, closer to the thalamus, probably within the thalamic reticular nucleus. Subplate projections reach the proximity of the diencephalon at an early stage, but they might never enter the dorsal thalamus.

Animals↗
PubMed2003

Decreased volume and increased asymmetry of the anterior limb of the internal capsule in patients with schizophrenia.

BACKGROUND: The anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncle connecting the medial and anterior thalamic nuclei with the prefrontal cortex and the cingulate gyrus. The purpose of this study was to detect the volumetric changes in the ALIC in view of the putative abnormal frontothalamic connectivity in schizophrenia. METHODS: High-resolution, three-dimensional magnetic resonance imaging was acquired from 53 schizophrenia patients and 48 age- and gender-matched control subjects. Volumetric analysis was performed using consecutive 1-mm-thick coronal slices rostral to the anterior commissure, on the ALIC, caudate nucleus, and lentiform nucleus. White matter concentration over the whole brain was compared using the voxel-based morphometry (VBM) with Statistical Parametric Mapping 99. RESULTS: The patients had significantly decreased volumes in the bilateral ALIC and showed significantly increased right-greater-than-left asymmetry of the ALIC; VBM revealed a reduction in white matter concentration of the bilateral internal capsule in patients. No volumetric difference was found in the rostral part of the caudate and lentiform nucleus between groups. CONCLUSIONS: Decreased volume found in the ALIC supports the hypothesis of abnormal frontothalamic connectivity in schizophrenia. Increased asymmetry of the internal capsule seems consistent with the notion of predominantly left-side pathology of schizophrenia.

Adult↗
PubMed2000

Mapping of fiber orientation in human internal capsule by means of polarized light and confocal scanning laser microscopy.

The nervous fibers in the human internal capsule were mapped according to their three-dimensional orientation. Four human cadaver brains were cut into comparable and standardized sections parallel to the ACPC-plane, stained with DiI, and analyzed using a combination of confocal and polarized light microscopy at the same time. This combination provides information about the structure and orientation of the fibers in great detail with confocal microscopy, and information about the localization and orientation of long myelinated fiber tracts with polarization microscopy. The internal capsule was parcellated in the areas CI 1 to CI 4 containing fibers of distinct orientation and structure, which enriches the macroscopically definable parcellation in the anterior and posterior limb. Fibers of the anterior thalamic peduncle intermingle with frontopontine tract fibers. Single fibers connect the caudate and the lentiform nucleus. The pyramidal tract is located in the anterior half of the posterior limb intermingled with fibers of the superior thalamic peduncle. Parietooccipitopontine fibers are located in the posterior part of the posterior limb. The slopes of the different systems of fibers change continuously in the anterior posterior direction of the internal capsule. Using the 3D orientation of fibers as a criterion for parcellation, as well as the description of bundles as a collection of fibers belonging to particular tracts leads to a more function-related description of the anatomy of the internal capsule. The method can be used for interindividual, sex- or age-related comparisons of particular systems of fibers.

Cadaver↗
PubMed2006

Deep brain stimulation in the internal capsule and nucleus accumbens region: responses observed during active and sham programming.

BACKGROUND: Recently, anterior limb of the internal capsule and nucleus accumbens deep brain stimulation (DBS) has been used in the treatment of medication-refractory obsessive-compulsive disorder (OCD). This region has been previously explored with lesion therapy, but with the advent of DBS there exists the possibility of monitoring the acute and chronic effects of electrical stimulation. The stimulation-induced benefits and side effects can be reversibly and blindly applied to a variety of locations in this region. OBJECTIVE: To explore the acute effects of DBS in the anterior limb of the internal capsule and nucleus accumbens region. METHODS: Ten total DBS leads in five patients with chronic and severe treatment-refractory OCD were tested. Patients were examined 30 days after DBS placement and received either "sham" testing or actual testing of the acute effects of DBS (the alternative condition tested 30 days later). RESULTS: Pooled responses were reviewed for comparability of distribution using standard descriptive methods, and relationships between the variables of interest were sought using chi2 analysis. A total of 845 stimulation trials across the five patients were recorded and pooled. Of these 16% were elicited from sham stimulation and 17% from placebo (0 V stimulation). A comparison of active to sham trials showed that sham stimulation was not associated with significant side effects or responses from patients. Non-mood-related responses were found to be significantly associated with the ventral lead contacts (0 and 1) (p = 0.001). Responses such as taste, smell and smile were strongly associated with the most ventral lead positions. Similarly, physiological responses--for example, autonomic changes, increased breathing rate, sweating, nausea, cold sensation, heat sensation, fear, panic and panic episodes--were significantly associated with ventral stimulation (p = 0.001). Fear and panic responses appeared clustered around the most ventral electrode (0). Acute stimulation resulted in either improved or worsened mood responses in both the dorsal and ventral regions of the anterior limb of the internal capsule. CONCLUSION: The acute effects of DBS in the region of the anterior limb of the internal capsule and nucleus accumbens, particularly when obtained in a blinded fashion, provide a unique opportunity to localise brain regions and explore circuitry.

Adult↗
PubMed1981

[The topology of the motor pathways in the internal capsule (author's transl)].

The topology of the motor pathways in the posterior peduncle of the internal capsule is discussed with regard to the literature and computer tomographic analysis of three patients with capsular lesions. Contradictory findings from morphologic, stereotactic, and computer tomographic investigations of the topology of the motor pathways in the posterior peduncle of the internal capsule have led to concepts which are mutually incompatible. It was first maintained that the motor pathways are located in the anterior third or two-thirds of the posterior peduncle and arranged somatotopically in the craniocaudal direction. A new interpretation which has received wide support from stereotactic investigations and studies of the pathologic anatomy of amyotrophic lateral sclerosis agrees on the somatotopic arrangement, but claims that the motor pathways are located rather in the posterior third of the posterior peduncle. By including ontogenetic factors and a critical relativistic consideration of the somatotopic arrangement of the posterior peduncle of the internal capsule in the analysis of the topology of the motor pathways in the posterior peduncle of the internal capsule, it can be demonstrated that the contradictions of published results and hypotheses are only apparent, thus making a uniform interpretation possible.

Amyotrophic Lateral Sclerosis↗