ISSN:0014-3022    

DOI:10.1159/000117191

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Basal ganglia have been known as a motor center because their lesions cause motor disturbances in involuntary movements such as chorea, ballism or akinesia in parkinsonism. The different types of involuntary movements are closely related to the underlying muscle tone. Mechanisms of bradykinesia or akinesia have been elaborated in physiological studies on Parkinson’s disease and the significance of sensorimotor processing or attention arousal has been disclosed as a relevant factor of bradykinesia. Analysis of short-stepped gait, frozen gait or apraxia of gait, has claimed the frontal lobe and the striatum to be a locomotion center especially in humans (bipedal locomotion). Cognitive function of the basal ganglia has attracted attention particularly in the disorder of Parkinson’s disease. Subcortical dementia, difficulty in formation or changes of concepts are encountered in advanced stages of Parkinson’s disease. Whether cognitive functions in the frontostriatal system are primarily related to the motor function of the brain is an issue for future

ISSN:0014-3022    

DOI:10.1159/000118876

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Paresthesiae, dysesthesiae, and hyperesthesiae (‘positive symptoms’) result from ectopic nerve impulses secondary to inappropriate membrane excitability which develops in the setting of chronic sensory axonal injury. The molecular changes in the membranes of dorsal root ganglion neurons which underlie ectopic impulse generation as a result of chronic axonal injury are unknown. Preliminary evidence has suggested that voltage-dependent Na+ channels are one of the participants in the production of ectopic impulses, but the precise form of their participation remains to be determined. The present paper reviews normal sensory anatomy and Na+ channel physiology, as well as clinical syndromes heralded by positive sensations and what is so far known about the cellular and molecular mechanisms underlying them. Properties of two distinct populations of Na+ channels native to the DRG neurons which give rise to cutaneous afferents are described. The biophysical properties of each population of Na+ channels must be tuned with respect to the other in order to cooperate in the generation of action potential activity underlying normal sensory function. A novel hypothesis is put forth suggesting that chronic axonal injury leads to intraneuronal heterogeneity of the populations of Na+ channels in cutaneous afferents, as revealed by their characteristic properties. This may result in one population of Na+ channels activating the other, leading to membrane instability, and possibly to ectopic impulse generat

ISSN:0014-3022    

DOI:10.1159/000117192

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Among the motor tetrad of Parkinson’s disease, akinesia is not easy to define and controversies still exist on the nature of akinesia. In 1972 Barbeau first described pure akinesia without rigidity or tremor responsive to L-dopa therapy, that is, akinesia due to striatal dopamine deficiency. Since 1974, Imai and Narabayashi have described a different type of pure akinesia, unresponsive to L-dopa treatment. This new condition exhibits only the freezing symptom, which is a breakdown of repetitive voluntary movements emerging through festination or suddenly, e.g., freezing of gait, micrographia and inaudible speech. Kinesie paradoxale is always accompanied by this type of akinesia. The author suggested that the main pathological structure of the condition was different from the nigrostriatal dopaminergic system and that the condition was different from Parkinson’s disease. Subsequently we expanded our experience to more than 30 patients. All patients were sporadic and slowly progressive, and some had been followed for more than 10 years, still without rigidity or tremor. Slowly progressive supranuclear opthalmoplegia appeared later in several patients, in which progressive supranuclear palsy (PSP) was strongly suggested. Autopsy cases associated with this condition have been reported and pathologically revealed PSP. The nosological position and responsible lesion sites of this condition are discus

ISSN:0014-3022    

DOI:10.1159/000118877

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

There is little information on skeletal muscle changes in patients with acute stroke. We performed morphological and histochemical examinations of nonhemiplegic sternothyroid muscles biopsied at the time of tracheostomy from 13 patients with acute stroke manifesting acute respiratory failure. Degenerating and regenerating fibers were observed in all 13 specimens. Following characteristic myopathic changes suggestive of mitochondrial abnormalities were also demonstrated in a majority of patients. Namely, ragged-red fibers, focal increase in NADH-TR activity in subsarcolemmal areas and increases in acid phosphate activity were found. The changes were similar but extremely slight in control patients with acute respiratory failure due to causes other than stroke and were absent in the other control patients with adenomatous thyroid tumor. The severity and extent of the histopathological changes in the muscle fibers in patients with acute stroke were closely correlated with the duration of hypoxemia but not with such items as type of stroke, site of cerebral lesion, consciousness level, days of biopsy after the stroke, clinical outcome, levels of serum creatine kinase, myoglobin and PaO2. This acute nonhemiplegic muscle involvement was considered to be a very common complication in severe stroke patients.

ISSN:0014-3022    

DOI:10.1159/000117193

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:0014-3022    

DOI:10.1159/000202991

出版商:S. Karger AG    

年代:1914

数据来源: Karger

摘要:

Leukoaraiosis, found on computed tomographic scans of the brain, is suspected to be of ischemic origin and is frequently associated with progressive decline of cognitive functions in elderly persons. Some of them also develop late-onset epilepsy. The present positron emission tomographic study investigates if these seizures in mentally nonaffected patients with leukoaraiosis are related to an underlying ischemic process. Patients with leukoaraiosis and late-onset seizures have a more important decline of regional blood flow and oxygen consumption in the cortical areas, compared to normal age-matched controls, to patients with cryptogenic symptomatic late-onset epilepsy and to patients with a similar degree of leukoaraiosis but without epilepsy. The present study suggests that both the late-onset seizures and the leukoaraiosis in patients with, at that time, no obvious mental deterioration are premonitory signs of an encephalopathy of unknown origin, possibly leading to cognitive decline.

ISSN:0014-3022    

DOI:10.1159/000117194

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Patients with Parkinson’s disease (PD) present with a wide range of cognitive and motor dysfunctions. Attempts to fit these deficits into a neuroanatomical framework have tended to emphasise their separateness. This paper, however, takes a broader perspective based on the concept of action – purposeful goal-directed behaviour – which serves to integrate the various deficits into a common framework. Of the motor symptoms of PD, akinesia is chosen as representing a breakdown in a distributed system of action control. Three aspects of akinesia are considered – slowness to initiate movement, slowness to execute movement and poverty of spontaneous movement. All are seen as being surface manifestation of the system’s attempts to cope with or adapt to the limitations imposed by the disease process, at a cognitive, motor and integrat

ISSN:0014-3022    

DOI:10.1159/000118880

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Eight patients with hypertensive encephalopathy from diverse etiologies developed cerebral edema in the vertebrobasilar distribution which resolved after blood pressure was lowered. Parietal occipital edema is a recognized feature of hypertensive encephalopathy. The explanation for this regional pathological variation in hypertensive encephalopathy remains undefined. Some evidence suggests that sympathetic innervation of the anterior cerebral vasculature may be protective, and conversely, the relative lack of sympathetic innervation in the vertebrobasilar vasculature may predispose the parietal occipital region to the development of cerebral edema in hypertensive encephalopathy.

ISSN:0014-3022    

DOI:10.1159/000117195

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:0014-3022    

DOI:10.1159/000202992

出版商:S. Karger AG    

年代:1914

数据来源: Karger