Biomedical subjects
Publications and source records attributed to M Kaps.
We report the case of a 72-year-old man suffering from posttraumatic subarachnoidal hemorrhage. After recovering from the initial impaired consciousness and posttraumatic psychosis the patient deteriorated again 7 days after the accident. Cerebral vasospasm was found to be the underlying cause. So far few publications have drawn attention to posttraumatic vasospasm, though this is also interesting from the aspect of treatment.
In this study 11 patients aged between 34 and 57 years with clinical and angiographic findings typical of carotid dissection were thoroughly examined with transcranial Doppler ultrasound (TCD) repeatedly during a follow-up period of 1-6 months. Stagnating blood flow velocities in the downstream middle cerebral artery (MCA) were recorded initially as well as enhanced velocities due to postischaemic hyperperfusion syndrome. MCA embolism originating from the extracranial carotid artery with or without resolution could be detected by TCD in 5 cases. TCD findings in another 2 cases pointed to haemodynamic upset. In 3 cases, clinical as well as TCD data did not allow strict differentiation between embolic and haemodynamic complications, suggesting more complex pathophysiological mechanisms as the cause of infarction. Carotid recanalization was seen in 9 cases. The follow-up investigations moreover demonstrated that intracranial haemodynamics may change from day to day in patients suffering from internal carotid artery dissection. TCD data may thus improve the understanding of pathogenetics as well as rationales for individual therapeutic intervention in this particular disease.
We evaluated the efficacy of transcranial Doppler ultrasonography in 23 patients suffering from acute middle cerebral artery occlusion. The diagnosis of occlusion was most suggestive when all basal arteries except the affected middle cerebral artery were detectable. Enhanced blood flow velocity in the anterior cerebral artery due to leptomeningeal collateralization was used as a corroborating criterion. With frequent follow-up examinations, we monitored reperfusion of the M1 segment resulting from recanalization or embolus migration in 16 patients. Those patients undergoing recanalization within days after onset of the first symptoms revealed variable clinical courses and lesion patterns on computed tomography, indicating the crucial importance of early and efficient leptomeningeal collateral blood supply. Transcranial Doppler ultrasonography was able to exclude middle cerebral artery occlusion with accuracy, which provides important clinical information. However, distal branch occlusions could not be detected with sufficient exactness.
Transcranial Doppler sonography (TCD) was used to determine the mean blood flow velocity of the middle cerebral artery (Vm-MCA) and pulsatility (systolic/diastolic flow velocity = S/D) in 25 patients undergoing aortocoronary bypass grafting before, during, and after extracorporeal circulation (ECC). Preoperatively, none of the patients had signs or symptoms of cerebrovascular disease. ECC was performed with 2.4 l/min per m2 under mild hypothermia (34 degrees C) using membrane oxygenators. After 20 min of nonpulsatile perfusion, ECC was switched to the pulsatile mode for 20 min. Nonpulsatile perfusion was applied for the remaining ECC period. Vm-MCA, S/D, mean arterial blood pressure (MABP), and nasopharyngeal temperature (T.np) were recorded continuously throughout the operation. Hematocrit and paCO2 were determined before, during, and after ECC. Following hemodilution after the introduction of ECC, Vm-MCA was significantly increased compared with the baseline values before ECC. With hematocrit and paCO2 varying insignificantly during ECC, the onset of pulsatile ECC decreased Vm-MCA and MABP simultaneously. After the re-establishment of nonpulsatile ECC, both Vm-MCA and MABP increased again. However, a linear relationship between the two variables could not be documented statistically. During pulsatile ECC, pulsatility (S/D) of the obtained TCD wave forms did not reach baseline values. In 4 cases, TCD showed cessation of diastolic blood flow velocity after induction of ECC or onset of pulsatile ECC. An increase in MABP or changes in ECC regimen promptly restored diastolic TCD signals in these cases. Our results support the concept of increased cerebral blood flow under mild hypothermic ECC. Compared with the nonpulsatile perfusion mode, we found Vm-MCA reduced during pulsatile ECC.(ABSTRACT TRUNCATED AT 250 WORDS)
Changes in blood velocity in the middle cerebral artery (MFV) were investigated by transcranial Doppler sonography (TCD) in 24 patients undergoing aortocoronary bypass grafting before, during, and after extracorporeal circulation (ECC). Simultaneously, mean arterial blood pressure (MABP), PaCO2, PaO2, and hematocrit were recorded. During ECC, an increase in MFV could be observed that was most pronounced during the early bypass stages. After ECC, MFV decreased slightly but was significantly higher than before ECC. No linear relationship between MFV and MABP could be registered except for the early bypass stage. Neither duration of ECC nor aortic clamping time showed any correlation with MFV augmentation. Mean PaCO2 was held constant (36 mmHg) with PaO2 being at least 120 mmHg. After removal of the aortic clamp, high-frequency Doppler signals probably caused by air or fragment embolization were detected in some patients. Our data support previous observations of increased cerebral blood flow during nonpulsatile ECC. During short episodes of low-pressure perfusion after initiation of ECC, cerebral autoregulation seemed impaired. However, our results do not support the concept of complete loss of autoregulation during ECC. Compared to the xenon technique of measuring cerebral blood flow, TCD allows noninvasive and continuous evaluation of cerebral hemodynamics, thus offering new possibilities of monitoring cerebral blood supply intraoperatively.
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Five patients, who developed progressive neurological deterioration within hours due to subarachnoid haemorrhage (SAH) are reported. The computertomographic (CT) appearance of a noncommunicating hydrocephalus (n.c.h.) was a unique feature in 4 cases. CT during the early phase of neurological deterioration after SAH permits the differentiation between an ischaemic, an oedematous, a haemorrhagic-compressive lesion and an increase in intracranial pressure (ICP) due to n.c.h.
Cryptococcosis must be taken into account as a cause of basal meningitis. Along with a case report, clinical signs and guiding cerebrospinal fluid findings are evaluated. Special attention is paid to CSF-cytology, which provides important information in terms of identification and clinical course of the disease. For the first time C. neoformans, yielded from CSF-samples, was investigated by means of scanning electron microscopy, and compared with yeast cultured in laboratory.
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The present article describes a patient with ischemia in the vascular territory of the posterior inferior cerebellar artery, who developed in addition to other typical signs of the dorsolateral medulla oblongata, myoclonic movements of the ipsilateral vocal cord. Within a period of one year, the myoclonic movement progressed, leading to bilateral involvement of the velo-pharyngeal muscles. The essential neuropathological lesion is considered to be an impairment of the dentato-olivary System. In this respect there is a close relationship to other types of rhythmical myoclonus due to lesions of the brain-stem and cerebellum.
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Lactic acid concentration has been determined in the cerebrospinal fluid (CSF) of 715 patients suffering from various neurological diseases. It was found to be most often elevated in cases of ischemic cerebral infarction, cerebral contusion, arteriosclerotic dementia, metastatic encephalitis, bacterial meningitis, menigiosis carcinomatosa and after epileptic seizures. In fewer cases lactate levels were increased with brain tumors, encephalitis, viral meningitis and radiculitis. Diagnostic relevance of CSF lactic acid determination is discussed with regard to ischemic cerebral disorders, differential diagnosis of viral and bacterial meningitis and for the confirmation of epileptic seizures.
Total CSF protein and CSF/serum albumin and alpha 2-macroglobulin ratios as indicators of a disturbed blood-brain barrier were determined in 39 cases of ischaemic cerebral infarction proved by computed tomography (CT). About 50% of the patients had a barrier disturbance, whereat the CSF serum albumin ratio was shown to be the most sensitive parameter. A disturbed blood-brain barrier was more often found in cases of large infarction, as shown by CT, and occurred most frequently in the first 2 weeks of illness. No correlation was seen between enhancement in CT and disturbance of the blood-brain barrier.
The present article describes a patient with ischemia in the vascular territory of the posterior inferior cerebellar artery, who developed, in addition to other typical signs of the dorsolateral medulla oblongata, myoclonic movements of the ipsilateral vocal cord. The essential neuropathological lesion is considered to be an impairment of the dentato-olivary system. In this respect there is a close relationship to other types of rhythmical myoclonus due to lesions of the brain-stem and cerebellum.
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Pulsatile wave patterns in basal cerebral arteries were studied by means of transcranial Doppler ultrasound (TCD) in 11 patients undergoing cardiopulmonary bypass (CPB) surgery. Different physiological states and technical parameters were demonstrated influencing wave forms delivered from a pulsatile CPB roller pump. The results gave evidence of the variability of pulsatile perfusion which may explain the inconsistency in the literature concerning its effectiveness in preserving tissue function. TCD proved to be a useful approach to define pulsatility of cerebral blood flow during CPB.