ISSN:1015-9770    

DOI:10.1159/000108674

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The cerebellum is the largest brain structure in the posterior fossa. However, cerebellar infarcts were understudied up to the 1980s. Now well shown by CT and MRI scans, we can distinguish between territorial infarcts - involving the full territory of a cerebellar artery or its branches - and borderzone infarcts. This can help to predict the vascular mechanisms of the ischemia. Territorial infarcts have a thrombo-embolic mechanism. Cardiac embolism is the most frequent. Artery-to-artery embolism, atherosclerotic disease of the vertebral artery (mainly in its intracranial part) or basilar artery, and vertebral artery dissection come next. Among them, the importance of intra-arterial embolism from vertebral artery origin disease deserves to be evaluated in the future because of the therapeutic implications. Borderzone or endzone infarcts may have a hemodynamic mechanism or be due to small emboli. The most frequent cause is occlusion of the vertebral or basilar arteries, either due to atheroma or embolism; small or end (pial) artery disease comes next, due to hypercoagulability states (e.g. thrombocythemia, polycythemia, disseminated intravascular coagulation), arteries or intracranial atheroma; systemic hypotension is seldom found. The new neuroimaging methods for the assessment of intracranial hemodynamics (transcranial Doppler, magnetic resonance angiography, positron emission tomography and single photon emission computed tomography) provide future opportunities for a better study of these patients and the natural history of these lesions, and for a better definition of the role of various therapies and revascularization procedure.

ISSN:1015-9770    

DOI:10.1159/000108675

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

FOS and JUN proteins are encoded by cellular early response or immediate early genes (IEGs). They act as transcription factors and are thought to represent third or fourth messengers in an intracellular cascade of stimulus transcription coupling, which converts neuronal excitation into a complex program of cellular responses that finally results in the regulation of target gene expression. Cloning of IEGs and generation of specific antibodies to individual IEG-encoded proteins have offered tools to study gene activation in situ. Recent investigations have demonstrated IEG induction in vivo in the nervous system after a variety of physiological and pathophysiological conditions including nociception, regeneration and epilepsy. Only a few studies have dealt with molecular details of stimulus transcription coupling after ischemia. The present review summarizes what is currently known about the coordinated activation of different IEGs in the central nervous system after experimental focal ischemia.

ISSN:1015-9770    

DOI:10.1159/000108676

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In order to evaluate whether hypotonia could be the clinical expression of crossed cerebellar diaschisis (CCD), we studied the occurrence and severity of CCD in two groups of hemiparetic stroke patients presenting either with prolonged muscular flaccidity (PMF, n = 14) or with muscular spasticity (MSp, n = 13) over the affected hemisoma. CCD was more frequent and severe in hypotonic than in spastic patients. Neither the time elapsed from the stroke nor the volume of the lesion was significantly different between patients with PMF and those with MSp. The two groups of patients showed different motor deficit scores, but motor deficit severity and CCD did not correlate. We concluded that the persistence of CCD after stroke may be associated with PMF, emphasizing the link between functional cerebellar impairment and muscular hypotonia.

ISSN:1015-9770    

DOI:10.1159/000108677

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Forty-seven patients presenting with symptoms of large middle cerebral artery territory infarcts were studied prospectively using serial CT brain scanning to assess infarct extent and swelling, and transcranial Doppler ultrasound to assess middle cerebral artery patency. The single most important determinant of cerebral infarct swelling was the extent of the infarct: the larger the infarct, the greater the amount of swelling (Spearman Rank correlation coefficient 0.74, p < 0.0001). In addition, if the blood velocity in the symptomatic middle cerebral artery did not increase in the first 5 days after symptom onset (implying no early reperfusion) the odds of severe infarct swelling were increased 7.6-fold (95% confidence interval 1.2- to 46.4-fold, 2p = 0.03), and the odds of a poor clinical outcome (dead or dependent in activities of daily living at 3 months) were increased 10-fold (95% confidence interval 2.7- to 41.6-fold, 2p = 0.0007). The only patients who recovered sufficiently to be able to return home by 3 months after stroke were amongst those whose symptomatic middle cerebral artery blood velocity increased (either spontaneously or associated with fibrinolytic or antithrombotic therapy) in the first 5 days after stroke. We conclude that early reperfusion is not associated with a worsening of acute cerebral infarct swelling, and may lead to a better clinical outcome.

ISSN:1015-9770    

DOI:10.1159/000108678

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The water content and concentration of eight elements (i.e. K, Ca, Mn, Fe, Cu, Zn, Se and Rb) were measured in postmortem samples of recent cerebral infarcts in the territory of the middle cerebral artery. The elemental determinations were performed by particle-induced X-ray emission analysis. Five patients had been treated with neurotropin and 6 with placebo. The most striking finding was a less significant increase in the water content in the white matter of the infarcts of patients who had been treated with neurotropin compared to those on placebo. Decreases in intracytoplasmic elements, such as Rb and Cu, and increases in Ca were more clearly present in the infarcts of patients who had been treated with placebo compared to neurotropin. This postmortem study in 11 humans shows that neurotropin inhibits vasogenic edema associated with recent cerebral infarction and protects against ischemic brain damage.

ISSN:1015-9770    

DOI:10.1159/000108679

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

We examined neurological deficits and infarct volumes, as determined by 2,3,5-triphenyltetrazolium chloride staining, 24 h after intraluminal suture occlusion of the middle cerebral artery (MCA) in 2 groups of 10 male Sprague-Dawley rats treated after the onset of ischemia with the noncompetitive N-methyl-D-aspartate antagonist, dizocilpine maleate (MK-801) or saline. Although MK-801 caused a significant drop in blood pressure, it significantly improved the neurological status 24 h after MCA occlusion (p < 0.0002). It reduced total infarct volume, 301 ± 30 mm3 in the control and 157 ± 46 in the MK-801-treated group (mean ± SEM, p < 0.02) and infarct areas in the caudoputamen (p < 0.01). Postocclusion MK-801 treatment protects ischemic brain damage even when a short duration of anesthesia is used with relatively long survival times in this stroke mod

ISSN:1015-9770    

DOI:10.1159/000108680

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The thermographic finding of a unilateral ''cold patch'' on the forehead of both classic and common migraine sufferers has prompted the suggestion that there is an asymmetry in the vasomotor tone of superficial extracranial arteries that could also be present in cerebral vessels. Transcranial Doppler sonography allows the study of the response of intracranial arteries to variations of blood pCO2, which may give an estimate of vasomotor tone regulation. Thirty headache-free migraineurs were compared to 30 age-matched controls. The provocative test consisted of a 30-second apnea, followed by hyperventilation for 1 min. End-tidal pCO2 was assessed by means of a capnometer. The mean flow velocity of the middle cerebral artery was monitored throughout the testing session by means of a 2-MHz transcranial Doppler probe. Baseline mean flow velocities were not statistically different between right and left sides in both controls and migraineurs and between ipsilateral (to the ''cold patch'') and contralateral side in migraineurs. During apnea migraineurs, ipsilaterally to the ''cold patch'', showed a significantly lower increment in mean flow velocity than controls. Following apnea and during maximal hyperventilation, migraineurs showed a bilateral vasoconstriction significantly more pronounced than controls. End-tidal pCO2 was not statistically different between migraineurs and controls. The findings suggest that the cerebral arterioles of migraineurs are more likely to undergo vasoconstriction when pCO2 is reduced. In addition, there seems to be a unilaterally more pronounced tendency to resist a vasodilatory stimulation.

ISSN:1015-9770    

DOI:10.1159/000108681

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Cerebrovascular reserve capacity (CVRC) was investigated in 13 insulin-dependent diabetic (IDDM) patients with clinical microangiopathy and in 12 healthy subjects. CVRC was assessed by transcranial Doppler (TCD) ultrasonography continuously recording mean blood flow velocity (FVm) of the middle cerebral artery in the resting condition and for 2 h after an i.v. injection of 1 g acetazolamide. The increase in FVm was observed a few minutes after the injection of acetazolamide with the highest value being reached after 10 min in both IDDM patients and controls. Each single curve was significantly increased in controls and in the diabetic group (p < 0.001 by one-way Anova analysis and the Scheffé test). When comparing FVm in IDDM patients and controls, the values of the IDDM patients were significantly lower at all times (p < 0.05). An age-dependent decline of FVm was observed in IDDM patients at rest (p = 0.016), but not in healthy controls (NS). The absolute increase in mean blood flow velocity after 10 min was 16.7 ± 8.5 cm/s (mean ± SD) in IDDM patients and 24.1 ± 9.3 cm/s in controls (p < 0.05), while 3 out of 13 IDDM patients had a CVRC below 1 SD of the control group. The acetazolamide test and TCD ultrasonography seem to be useful methods for assessing CVRC in IDDM patie

ISSN:1015-9770    

DOI:10.1159/000108682

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A 35-year-old man presented with acute aphasia and a left parietal infarction demonstrated by magnetic resonance imaging. He did not have an obvious etiology for stroke except for a patent foramen ovale detected by contrast echocardiography. A simultaneous transcranial Doppler ultrasound examination detected microbubbles in the middle cerebral artery. A deep venous thrombus was also detected. It is presumed that a paradoxical embolization occurred through a patent foramen ovale with target organ involvement demonstrated by the transcranial Doppler study. Transcranial Doppler may be used to detect paradoxical embolism in patients with acute stroke of undetermined cause.

ISSN:1015-9770    

DOI:10.1159/000108683

出版商:S. Karger AG    

年代:1993

数据来源: Karger