1/26. Basal forebrain amnesia: does the nucleus accumbens contribute to human memory?OBJECTIVE: To analyse amnesia caused by basal forebrain lesions. methods: A single case study of a patient with amnesia after bleeding into the anterior portion of the left basal ganglia. Neuropsychological examination included tests of attention, executive function, working memory, recall, and recognition of verbal and non-verbal material, and recall from remote semantic and autobiographical memory. The patient's MRI and those of other published cases of basal forebrain amnesia were reviewed to specify which structures within the basal forebrain are crucial for amnesia. RESULTS: attention and executive function were largely intact. There was anterograde amnesia for verbal material which affected free recall and recognition. With both modes of testing the patient produced many false positive responses and intrusions when lists of unrelated words had been memorised. However, he confabulated neither on story recall nor in day to day memory, nor in recall from remote memory. The lesion affected mainly the nucleus accumbens, but encroached on the inferior limb of the capsula interna and the most ventral portion of the nucleus caudatus and globus pallidus, and there was evidence of some atrophy of the head of the caudate nucleus. The lesion spared the nucleus basalis Meynert, the diagnonal band, and the septum, which are the sites of cholinergic cell concentrations. CONCLUSIONS: It seems unlikely that false positive responses were caused by insufficient strategic control of memory retrieval. This speaks against a major role of the capsular lesion which might disconnect the prefrontal cortex from the thalamus. It is proposed that the lesion of the nucleus accumbens caused amnesia.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
2/26. Pathogenesis of pigment and spheroid formation in Hallervorden-Spatz syndrome and related disorders.In a case of Hallervorden-Spatz syndrome, neuromelanin was found in neurons and, extracellularly, in the globus pallidus and pars reticulata of the substantia nigra. Some cells of pars compacta contained Lewey bodies. We propose that neuromelanin is formed by a metal-catalyzed pseudoperoxidation of lipofuscin, involving increased amounts of iron and copper in the affected regions. A similar mechanism of spheroid formation, often associated with neuromelanin, may result from pathologic accumulations of lipid peroxides during fatty acid oxidation of myelin. We suggest that neuromelanin is a late stage in the metabolism on intraneuronal and extraneuronal lipopigments. Discrepancies among the histochemical features of the pigment in different cases may be explained by differences in amounts of lipofuscin, neuromelanin, and their precursors. We propose relation of peroxidation to the pathogenesis of some related degenerative diseases.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
3/26. Delayed encephalopathy after strangling.An 11-year-old boy who had been the victim of a strangling attempt was asymptomatic for one week whereupon involuntary movements involving the trunk and limbs developed, along with repetitive episodes of opisthotonos and autonomic dysfunction. Meanwhile, he remained alert and appeared to be mentally intact. An electroencephalogram was normal. He died 13 weeks after the onset of the neurological disorder. The neuropathological examination showed cavitating lesions in the caudate nucleus, putamen, and globus pallidus bilaterally, with sparing of the white matter. The delayed onset of a progressively evolving neurological disorder has been noted in various forms of hypoxicischemic insult, including previously reported cases of strangling, but its occurrence cannot be predicted from the preceding clinical state or course. In the cases in which abnormal movements have been predominant, the pathological findings have been similar despite diversity in the preceding circumstances. We suggest the underlying metabolic disorder common to these cases may be lactic acidosis, and that they should be studied for evidence of a biochemical defect.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
4/26. autopsy case of acute encephalopathy linked to familial hemiplegic migraine with cerebellar atrophy and mental retardation.A 19-year-old female patient, who had exhibited esotropia, mild cerebellar ataxia, mild mental retardation, and cerebellar atrophy on magnetic resonance images at the age of 15, developed signs of acute encephalopathy, and thereafter died of disseminated intravascular coagulation on the day of her admission. Both her mother and sister suffered from attacks of hemiplegic migraine, mild mental retardation, and cerebellar ataxia. Neuropathological examinations revealed acute changes in the widespread cerebral cortex, chronic degenerative changes in the anterior lobe of the cerebellar vermis, axonal spheroids in the Goll's nucleus, pseudo-calcinosis in the globus pallidus, and glial bundles in the cranial nerves. The most fascinating features were changes of purkinje cells, such as cactuses (asteroid bodies, dendritic expansions), somatic sprouts, and torpedoes. These changes may be characteristic of familial hemiplegic migraine with cerebellar atrophy, as well as the other metabolic diseases, such as Menkes' kinky hair disease, infantile (Tay-Sachs type) amaurotic idiocy, organic mercury intoxication, and mitochondrial encephalopathy, of which cases often exhibit such pathological changes of purkinje cells. Therefore, familial hemiplegic migraine may share some metabolic abnormalities with the diseases mentioned above.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
5/26. brain magnetic resonance imaging in tyrosinemia.A 3.5-year-old girl with tyrosinemia is reported. A computed tomography scan of the abdomen revealed multiple hepatic nodules. brain magnetic resonance imaging revealed bilateral high-signal changes confined to the globus pallidus on T2-weighted images. globus pallidus lesions likely represented neuropathologic changes such as astocytosis, delayed myelination, and status spongiosus (myelin splitting and vacuolation).- - - - - - - - - - ranking = 1.2026458992966keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
6/26. Diffuse cerebral white matter T2-weighted hyperintensity: a new finding of general paresis.General paresis (parenchymatous neurosyphilis) is a rare disease, and in recent years the number of papers published on the magnetic resonance imaging findings has been limited. The findings are as follows: cerebral atrophy; mesiotemporal T2 hyperintensity; ventriculomegaly; pathological T2 hypointensity of the globus pallidus, putamen, the head of the caudate nucleus and thalamus. We present a new finding, diffuse cerebral white matter T2 hyperintensity, observed in a patient with general paresis with a 5-year history of progressive dementia.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
7/26. striatonigral degeneration. A clinicopathological study.The clinical and pathological features of 10 cases of striatonigral degeneration are described: 5 were misdiagnosed in life as Parkinson's disease. Retrospectively, helpful early pointers to the diagnosis in these cases included unexplained falls, autonomic dysfunction, absence of rest tremor and failure to respond to L-dopa, but these were not always present. The pathological diagnosis could not be excluded on macroscopic examination of the striatum. Relative preservation of the putamen occurred in the 4 patients who benefited from L-dopa. The caudate nucleus was involved in all cases and there was no sparing of the large striatal neurons. In mild cases, involvement of the putamen was confined to its posterior two-thirds, dorsolaterally. With increasing severity this extended in a dorsal to ventral and posterior to anterior direction. Seven of the cases had evidence of olivopontocerebellar damage, but only 2 of these had clinical evidence of cerebellar disease. Correlation was found between the neuronal counts in caudate:putamen, striatum:nigra compacta, globus pallidus:nigra compacta, nigra compacta:locus coeruleus. The most severely involved part of the substantia nigra pars compacta was the ventrolateral zone, which projects to the dorsal putamen, the earliest site of striatal disease.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
8/26. frontal lobe syndrome in a patient with bilateral globus pallidus lesions.This article describes a patient who experienced the rapid onset of an irreversible behavioral change while vacationing in La Paz, bolivia (altitude, 4070 m). The only lesions demonstrated on a magnetic resonance imaging scan were bilateral hemorrhages in the globus pallidus. The behavior change was characterized by apathy and lack of motivation, features commonly associated with bilateral frontal lobe disease. This case is a further demonstration of how subcortical lesions can produce behavioral syndromes that are clinically indistinguishable from classic cortical syndromes. It is cases such as this that show how a strict localizationist concept of behavioral function is too restrictive and how it is necessary to consider a wide network of neuronal interconnections when explaining the mechanism of a dissolution of complex higher functions.- - - - - - - - - - ranking = 5keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
9/26. role of contrast enhancement in cerebral CT of carbon monoxide poisoning.Postcontrast cerebral CT offers advantages as an adjunct to noncontrast CT in the evaluation of patients with carbon monoxide intoxication. It is of particular value when the noncontrast CT is normal with its ability to enhance otherwise isodense lesions. In this regard it can more accurately define the extent of the CNS insult and in some instances offer insight into the patient's eventual clinical outcome. Contrast medium was useful in this instance to more clearly elucidate typical injury to globus pallidus as well as rather unusual involvement of putamen.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
10/26. Infantile bilateral striatal necrosis. Clinicopathological classification.Two cases of infantile bilateral striatal necrosis (IBSN) were studied retrospectively, and the literature was reviewed. The two children had presented with progressive neurologic signs of involuntary movements or muscle hypertonia from infancy. Initial computed tomography scans showed mild atrophy of the caudate nuclei or basal ganglia, and the neuropathologic examination revealed diffuse neuronal loss with some patchy preservation and marked astrogliosis in the striatum and globus pallidus. The 27 reported cases of IBSN were divided into three groups with characteristic clinical and pathologic features: early, acute onset (four cases); early, gradual onset (16 cases); and late onset (seven cases). Although metabolic changes in the developing corpus striatum may be important in the pathogenesis of IBSN, the origin is uncertain.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
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