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PubMed2006

Diffusion tensor imaging in the assessment of normal-appearing brain tissue damage in relapsing neuromyelitis optica.

BACKGROUND AND PURPOSE: Normal-appearing brain tissue (NABT) damage was established in multiple sclerosis by histology, MR spectroscopy, magnetization transfer imaging and diffusion tensor imaging (DTI). However, whether this phenomenon can be detected in relapsing neuromyelitis optica (RNMO) remains unclear. The aim of this study was to use DTI to investigate the presence of NABT damage in RNMO patients and its possible mechanism. METHODS: Conventional MR imaging and DTI scans were performed in 16 patients with RNMO without visible lesions on brain MR imaging and in 16 sex- and age-matched healthy control subjects. Histogram analysis of mean diffusivity (MD) and fractional anisotropy (FA) was performed in the entire brain tissue (BT), white matter (WM), and gray matter (GM). Region of interest (ROI) analysis of MD and FA was also performed in WM regions connected with the spinal white matter tracts or optic nerve (including medulla oblongata, cerebral peduncle, internal capsule, and optic radiation), in corpus callosum without direct connection with them, and in some GM regions. RESULTS: From histogram analysis, we found the RNMO group had a higher average MD of the BT, WM, and GM, a lower average MD peak height and a higher average MD peak location of the GM, and a higher average FA peak height of the WM than did the control group. From ROI analysis, compared with control subjects, RNMO patients had a higher average MD and a lower average FA in ROIs of WM connected with the spinal white matter tracts or optic nerve and a normal average MD and FA in corpus callosum without direct connection with them. In addition, a high average MD was found in parietal GM in these patients. CONCLUSIONS: Our findings confirm the presence of abnormal diffusion in brain tissue in patients with RNMO and suggest that secondary degeneration caused by lesions in the spinal cord and optic nerve might be an important mechanism for this abnormality.

Adult↗
PubMed2006

[Precocious puberty caused by hCG-producing germinoma involving the bilateral basal ganglia and cerebral white matter without 1ypical radiologic findings: case report].

An 8-year-old boy presented with a rare case of germinoma involving the bilateral basal ganglia and cerebral white matter manifesting as precocious puberty. Magnetic resonance (MR) imaging at the initial presentation demonstrated mild hyperintense areas in the bilateral basal ganglia and corpus callosum on T1-weighted images, and a small hyperintense spot in the right internal capsule on T2-weighted images. Human chorionic gonadotropin (hCG) level was elevated in the cerebrospinal fluid (CSF), so we strongly suspected that threre was a hCG-producing germinoma originating in the bilateral basal ganglia. Stereotactic biopsy was performed. Histological examination revealed two-cell pattern germinoma. After three cycles of combination chemotherapy consisting of ifosfamide, cisplatin, and etoposide, followed by whole brain irradiation with a total dose of 24 Gy, the CSF hCG level fell below the detection limit, but MR imaging demonstrated no significant change. Intracranial hCG-producing germinoma should be suspected in patients presenting with precocious puberty and elevated CSF hCG level. Moreover, slight intensity change on MR imaging is important to identify germinoma arising from the basal ganglia in the early stage.

Basal Ganglia Diseases↗
PubMed2006

Multiple intracranial arterial stenoses in association with thyrotoxicosis: a case report.

A 26-year-old young man, had Graves' disease in hyperthyroid state, presented with frequent episodic transient left hemiparesis and mild slurred speech lasting for few minutes to 2 hours for one month. Infarction at posterior limb of right internal capsule was found on brain MRI. Angiography revealed multiple intracranial arteries stenoses around the circle of Willis. After treatment with propylthiouracil and aspirin, his thyroid function returned to normal and the patient remained free from stroke.

Adult↗
PubMed2006

Unilateral pallidotomy produces motor deficits and excesses in rats.

PURPOSE: To better understand the behavioral effects of pallidotomy as a treatment for a range of movement disorders, including Parkinson's disease, chorea, and ballismus. In some cases, pallidotomy increases movement whereas in others it decreases unwanted motor behavior. METHOD: The present study investigated the effects of unilateral pallidotomy in rats with an otherwise healthy nervous system. Pallidotomized and sham lesion rats were evaluated on a battery of tests that measure sensorimotor behavior. RESULTS: Compared to sham lesion controls, pallidotomized rats showed motor deficits (forelimb placing; bracing) and excesses (locomotor behavior) as well as sensorimotor asymmetries (ipsilateral adhesive patch bias; increased contralateral foot faults). CONCLUSION: Motor deficits observed after pallidotomy were similar to those reported in previous research from this and other laboratories following damage to the nigrostriatal pathway or sensorimotor cortex. Motor excesses after pallidotomy are consistent with current theories of globus pallidus function. Taken together, these data suggest hypokinetic effects of pallidotomy may be related to fibers of passage (i.e. internal capsule), while hyperkinetic effects may be related to damage of pallidal cell bodies. These data may have important clinical implications because they suggest that regardless of the state of existing pathology, pallidotomy may create unwanted behavioral side effects.

Analysis of Variance↗
PubMed1990

Cellular localization of an HIV-1 antigen in subacute AIDS encephalitis using an improved double-labeling immunohistochemical method.

Among 102 brains obtained from patients with acquired immune deficiency syndrome (AIDS), 34 cases with subacute AIDS encephalitis were characterized by immunohistochemistry using an antibody that binds to a human immunodeficiency virus-1 (HIV-1) envelope glycoprotein, gp41. This glycoprotein was detected in mononucleated and/or multinucleated cells in 90% of adult and 50% of pediatric brains with subacute AIDS encephalitis. In addition, many gp41-positive cells with bipolar or multipolar processes were found in 10 cases, and these cells occurred most frequently in the basal ganglia and internal capsule. The phenotype of the gp41-positive cells was determined using an improved double-labeling immunohistochemical technique that employed beta-galactosidase and peroxidase conjugated reagents. Cell-type specific markers for double-labeling included: Ricinus communis agglutinin-1 (RCA-1) for macrophages and microglia; Ulex europaeus agglutinin-1 for endothelium; anti-glial fibrillary acidic protein (GFAP) for astrocytes; anti-amyloid precursor protein for neurons; and anti-leukocyte common antigen for leukocytes. Results of double-immunostaining revealed that gp41-positive cells of all morphologic types, including cells with bipolar or multipolar processes, were double-labeled with RCA-1, but not with markers for astrocytes, neurons, or endothelia. These findings support the contention that HIV-1 infection of the CNS is predominantly restricted to cells of the macrophage/microglia lineage.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Progression of morphological changes within CNS in a transgenic rat model of familial amyotrophic lateral sclerosis.

UNLABELLED: An analysis of the dynamics of histological and immunocytochemical changes in the CNS of a transgenic rat model of fALS in various periods of life was performed. Material was obtained from animals on the 60th day of age (4), 93rd day of age (3) and 120th presymptomatic day and from 3 animals in paretic stage of the disease. Formalin-fixed and paraffin-embedded slices were stained with HE and Klüver-Barrera method. Immunoreactions to GFAP, S-100, ferritin, neurofilament, ubiquitin, synaptophysin and tau protein were also performed. Within the brain tissues patchy neuronal loss and dark or ischaemic neurons were dispersed in cortical layers, CA1, CA3 and CA4 hippocampal areas and structures of the hemispheres and brain stem. In the spinal cord, numerous alpha motoneurons were dark or ischaemic. Vacuoles or small pale spots were visible in their cytoplasm. Microspongiosis surrounded some motoneurons, particularly cells subjected to neuronophagy. Neuronophagy, sporadically observed at the age of 60th day, was more extensive on the 93rd day of age, and at the age of 120 days already involved all interneurons of the anterior and posterior horns. In the immune reaction to neurofilament numerous fibres, often thick, fragmented or rosary-like, were observed. They were located within subcortical white matter, external and internal capsules, anterior horns of the spinal cord. Changes became more intensive with age. Astrocytic reactivity was weak in animals on the 60th and 93rd day of life. Non-numerous cells were immunoreactive to GFAP and S-100, although an increase of astrocytic nuclei was observed. On the 120th day of age and in symptomatic stage astrocytic hypertrophy and proliferation were intensive. But from the 60th day of age ubiquitin and tau protein immunopositive material was accumulated in the perinuclear area of astroglial cytoplasm. Immunoreaction of nerve cells to these proteins was negative. CONCLUSIONS: 1) In the subclinical stage of the disease the pathological process within the CNS takes place already on the 60th day of age and its intensity increases with age. 2) Morphological changes are not limited to motor neuronal cells. Various structures of the CNS are damaged. 3) Weak astroglial reaction probably depends on pathological accumulation of ubiquitin and tau protein in cytoplasm. 4) Astroglial cells are probably also a "target" for pathogenic factors in the rat model of fALS.

Age Factors↗
PubMed2006

[A case of primary central nervous system malignant lymphoma developing from the optic chiasma and hypothalamus].

A 63-year-old woman was admitted to our hospital with a 1-month history of visual field defect and reduced bilateral visual acuity. Neurological examination revealed enlargement of bilateral central scotoma and blurred vision, and brain MRI showed masses in the optic chiasma and right hypothalamus on Ti-weighted image with contrast enhancement. Although the patient was treated with high-doses of methylprednisolone four times, the masses spread to the right internal capsule and the vicinity of the right lateral ventricle. An open biopsy was performed and microscopic examination of the sample revealed lymphoplasmacytic lymphoma. Although primary central nervous system lymphoma (PCNSL) developing from the optic chiasma and hypothalamus is rare, PCNSL should be considered in patients with multiple lesions in the optic chiasma and hypothalamus.

Brain Neoplasms↗
PubMed2006

[Diffusion tensor imaging of the white matter tracts in preoperative patients with cerebral neoplasm].

OBJECTIVE: To evaluate the quantitative relationship between white matter tract (WMT) variation resulting from cerebral tumors and shifting of the fractional anisotropy (FA) index in magnetic resonance (MR) diffusion tensor imaging (DTI). METHODS: Four female and 8 male patients aged from 21 to 62 years with brain malignancies (2 malignant lymphomas, 2 low-grade astrocytomas, and 8 high-grade cerebral gliomas) underwent conventional contrast-enhanced MR and DTI examinations before operation. Routine T(2)-weighted image, fractional anisotropic (FA) map, color-coded directional map, three-dimensional white matter tractography (WMT), and the FA index of bilateral internal capsule were obtained in every patient. RESULTS: Fiber tractography derived from DTI was consistent with known white matter fiber anatomy. The DTI patterns in WMT altered by the tumor were categorized on the basis of FA1/FA2 ratio as follows: pattern 1, FA1/FA2> or =75% with normal or only slightly decreased FA; pattern 2, 50%< or =FA1/FA2<75% with WMT displacement; pattern 3, 25%< or =FA1/FA2/50% with WMT involvement; pattern 4, FA1/FA2<25% with WMT destruction. CONCLUSIONS: DTI allows for visualization of WMT and benefits surgical planning for patients with intrinsic brain tumor. There is a positive relationship between the bilateral FA ratio (FA1/FA2) variation and WMT alterations resulting from the tumor.

Adult↗
PubMed1990

[Does circumscribed ischemic white matter lesion produce neuropsychological symptoms?].

In order to determine a possible role of ischemic white matter lesion in producing neuropsychological symptoms, we conducted a retrospective survey. Subjects were 206 consecutive patients who had been admitted to our neurology service under the diagnosis of ischemic stroke from April 1988 to November 1989 and had received brain CT as well as SPECT scans. From this cohort only patients that had circumscribed white matter lesion on CT scans were selected. Patients who had lesion in basal ganglia or thalamus were rigidly excluded. Eight subjects (3.9%) fulfilled above criteria, i.e. 5 with left hemispheric, 2 with right hemispheric and 1 with bilateral white matter lesions. Then we supplemented MRI information which had happened to be available for all the eight subjects. Exclusion of grey matter lesion based on MRI reduced the number of cases with exclusive white matter lesion into 4, i.e. 3 with left hemispheric and 1 with right hemispheric lesion. Of these, only one case with a discrete lesion in the genu of the left internal capsule had manifested mild neuropsychological impairments in naming, comprehension and writing. I123 amphetamine SPECT study revealed low uptake in the anterior half of the left middle cerebral artery in this case. We conclude that the role of a circumscribed white matter lesion as a cause of neuropsychological symptom seems to be much less clear than has been postulated.

Adult↗
PubMed2006

Ischemic stroke following mild head injury is it the cause.

Recognition of childhood stroke is difficult. Newer diagnostic modalities like magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) have made this task much easier. Head trauma usually causes hemorrhage. We are presenting seven cases of mild head injury presenting as ischamic stroke. Neuroimaging suggested infarct involving left basal ganglia and internal capsule in five and bilateral involvement in two cases. MRA done in three was normal.

Brain Infarction↗
PubMed2006

[Hashimoto's encephalopathy with bilateral pallidal lesions presenting memory disturbance and executive dysfunction].

A 76-year-old man began to mistake his family for another person, and fall asleep easily while watching TV. He was treated with donepezil but without any effect. He was referred to our hospital on June. On admission, his consciousness was alert. Cranial nerves and motor functions were normal, but pathological reflexes were positive bilaterally. Serological examinations revealed high titers of antibodies against thyroglobulin and TPO, and antibody against alpha-enolase was positive. Total protein level in CSF was 40 mg/dl and cell counts were normal. On MRI, localized symmetrical lesions were observed in bilateral pallidum to genu of internal capsule. SPECT revealed hypoperfusion areas in bilateral striate bodies and frontal lobes. Neuropsychological examinations indicated impairment of executive function and procedural memory. The diagnosis of Hashimoto's encephalopathy was made and we treated the patient with oral prednisolone 60 mg/day followed by gradual tapering. After the treatment, clinical symptom as well as neuropsychological function improved. Neuropsychological impairment in this case was probably due to the disconnection of the thalamo-frontal projection. This case provides interesting suggestions that Hashimoto's encephalopathy may present with vasculitic infarctions in bilateral MCA perforators, and that this disease should be included in one of the differential diagnoses of cerebral infarctions of unknown etiology.

Aged↗
PubMed1991

[HIV encephalopathy].

The early manifestation of HIV infection of the brain, HIV encephalitis, is due to the invasion of HIV infected mono- and multinuclear macrophages into the brain tissue and cerebrospinal fluid. These cells are intensely PAS reactive, auto-fluorescent and express the macrophage antigen CD68. They clearly prefer the white matter of cerebral hemispheres, corpus callosum and internal capsule. Lymphocytic infiltrates and microglial nodules are additional, unspecific changes. HIV encephalopathy following HIV encephalitis is patho-anatomically characterized by brain tissue damage. Its clinical correlate is so-called AIDS dementia complex. It presumably is caused by neurocytotoxic and myelinotoxic factors released by activated macrophages and/or by shedding HIV retrovirus proteins. HIV encephalopathy includes leukoencephalopathy, diffuse poliodystrophy, disseminated basal ganglia damage and brain atrophy. In some cases, granulomatous angiitis may occur.

AIDS Dementia Complex↗
PubMed1991

Aluminum deposition in the central nervous system of patients with amyotrophic lateral sclerosis from the Kii Peninsula of Japan.

Chronic dietary deficiency of calcium (Ca) and magnesium (Mg) with excessive intake of aluminum (Al) and manganese (Mn) has been implicated in the pathogenesis of high incidence amyotrophic lateral sclerosis (ALS) in the Western Pacific. We report two cases of ALS from the Kii Peninsula of Japan with markedly elevated concentrations of Al in central nervous system (CNS) tissues. Six pathologically verified cases of ALS and five neurologically normal controls were studied. Levels of Al, Ca and phosphorus (P) were determined simultaneously by neutron activation analysis (NAA), and Mg concentration was measured by inductively coupled plasma emission spectrometry (ICP) in 26 CNS regions. Al concentrations in the precentral gyrus, internal capsule, crus cerebri and spinal cord were significantly increased in two ALS patients, compared with those of controls. Mean Al concentrations of the 26 CNS regions in these two patients were also higher than those of controls and of the four other ALS cases (p less than 0.01). By contrast, Mg concentrations in the 26 CNS regions were markedly reduced in the ALS cases, compared with controls (p less than 0.01), and the Ca/Mg ratios were significantly increased in the ALS cases (p less than 0.01). Our data indicate that high-incidence ALS in the Western Pacific may result from Ca-Mg dysmetabolism with resultant deposition of Al.

Aged↗
PubMed1991

CT appearance of shearing injuries of the brain.

Shearing injuries, also called diffuse axonal injuries, are a special kind of severe head trauma, usually caused by a motor vehicle accident, in which disruption of white matter axons takes place. Twelve cases of shearing injuries were diagnosed by computed tomography (CT). The typical CT findings were small hemorrhagic lesions in the cerebral white matter, most often in cerebral hemispheres and internal capsules. In most patients, hemorrhagic foci were multiple. Single lesions were found in only two patients. Features of brain edema were found in eight of ten early studies, and subarachnoidal hemorrhage only in three. Two patients also had subdural hematomas. CT appearance of the shearing injuries is characteristic, especially in connection with clinical data indicating a history of head trauma and severe state of the patient.

Accidents, Traffic↗
PubMed1991

[Demonstration of the excitatory effect of the thalamo-subthalamic efferent from the parafascicular nucleus].

The synaptic effect of the projection from an intralaminar thalamic structure, the parafascicular nucleus, to the subthalamic nucleus was investigated through extracellular recordings of subthalamic unit activities. Electrical stimulation of the parafascicular nucleus caused a complex response with two successive excitatory phases. The first excitation was assumed to be monosynaptically driven since it was not affected by pallidal lesion or transsection of the internal capsule. Pharmacological activation of the parafascicular neurons through microinjections of carbachol elicited a prolonged increase in the subthalamic discharge rate. These results suggest that the intralaminar parafascicular nucleus contributes to the activation of subthalamic neurons.

Animals↗
PubMed1991

[Ataxic hemiparesis and simultaneous supra- and subtentorial hematomas].

In a chronically hypertensive woman with a rapidly developing right ataxic hemiparesis syndrome, computed tomography and magnetic resonance imaging (MRI) revealed two small unrelated hemorrhages: one in the posterior limb of the left internal capsule, the other in the right cerebellar hemisphere. In this patient, the ataxic hemiparesis syndrome might have resulted either from the association of the two lesions or from the capsular hemorrhage alone. The rarity of simultaneous hypertensive hematomas and the value of MRI in the diagnosis are underlined.

Aged↗
PubMedDate not supplied

Particulate embolization of the anterior choroidal artery in the treatment of cerebral arteriovenous malformations.

The anterior choroidal artery is commonly recruited to supply arteriovenous malformations in the temporal lobe, basal ganglia, lateral ventricle, and internal capsule. Embolization of this artery is theoretically hazardous owing to its supply to important motor territory, relative lack of collaterals, and small caliber. However, this procedure can be a beneficial adjunct to surgery or radiation in the treatment of arteriovenous malformations. We describe our experience in performing particulate embolization of the anterior choroidal artery in 15 patients (16 procedures). Significant flow reduction was achieved in 14 patients. Two symptomatic and two asymptomatic complications arose, including permanent hemiparesis in one patient.

Adolescent↗
PubMedDate not supplied

Diffusion imaging of the human brain: a new pulse sequence application for a 1.5-T standard MR system.

We developed a new pulse sequence and investigated whether the anisotropic diffusion in the human brain can be detailed with a standard whole-body MR imager. Apparent diffusion coefficient maps were produced by the proposed sequence using a 1.5-T MR unit. The sequence employed simultaneous application of three orthogonal gradients to achieve an optimal signal attenuation for imaging the brain without any increase in echo time. The orientation of the effective diffusion-encoding gradient was off-axis. On the in vivo apparent diffusion coefficient maps of four healthy volunteers, white matter tracts (the internal capsule and the corpus callosum) and the cortical and deep white matter showed anisotropic diffusion. In the gray matter, such as basal ganglia and thalami, anisotropic diffusion was not observed. A typical whole-body imager can provide in vivo human brain diffusion images of clinical quality. This technique has promising implications for the evaluation of brain development and the diagnosis of degenerative diseases.

Adult↗