Cerebral blood flow changes in acute experimental haemorrhagic vasospasm

Subarachnoid haemorrhage was produced in 26 dogs by injecting fresh homogenous blood into the cysterna chiasmatica. Two types of vasospasm were observed, firstly segmental arterial spasm closely related to the bleeding point and secondly generalized arterial vasospasm not directly related to the bleeding point and often occurring some way from the bleeding point. Reduction in CBF occurred in 61% of cases and was always accompanied by radiological vasospasm. However, in about one quarter of the cases with vasospasm there was no alteration in CBF.     

Cerebral blood flow in subarachnoid hemorrhage

Myelin protein zero (MPZ, P0) is well known as the adhesion molecule responsible for the compaction of the myelin sheath of peripheral nerves. Mutations are linked to Charcot-Marie-Tooth syndrome type 1B (CMT1B) and the more severe Dejerine-Sottas syndrome (DSS). Three mutations leading to phenotypes of increasing severity (Ser34del/CMT1B, Ser34Cys/DSS, INS663GC/DSS) were expressed in S2 insect cells and resulted in a decreased adhesion capability in correlation with their respective phenotypes.     

Cerebral blood flow and EEG changes in preterm infants with patent ductus arteriosus

It is unknown whether the decreased cerebral blood flow seen in infants with a large patent ductus arteriosus is associated with cerebral dysfunction. Decreased cerebral blood flow in adult human and animal models has been associated with altered electroencephalography (EEG), spectral-analyzed EEG, and EEG response to photic stimulation. Cerebral blood flow velocity, EEG, spectral analysis of EEG, and photic alteration of EEG spectra were evaluated in 8 infants before and after closure of a significant patent ductus arteriosus and in 10 control infants without a patent ductus arteriosus. All infants with patent ductus arteriosus had moderate or large shunts associated with a 25% mean reduction in cerebral blood flow velocity. There were no differences, however, in EEG, spectral analysis of EEG, or photic alteration of the spectral analysis for these infants before and after patent ductus arteriosus closure as compared to controls. It is concluded that the degree of decreased cerebral blood flow in infants with a significant patent ductus arteriosus is not sufficient to cause measurable alteration in electrocortical activity.     

Cerebral blood flow in the diabetic patient

Asthma affects about 1 in 10 children. The condition is characterized by acute respiratory distress brought on by environmental factors. The condition is treated with medications aimed to reduce reaction to stimulants by the airway. Dental management involves attention to the status of the patient and awareness of stimulants of the reactive airway. Clinical recommendations are provided.     

Craniometric measures in cluster headache patients

Because of the striking similarity between histopathological pictures of chronic trichomonal cervicitis uteri, the tissue reaction after subcutaneous inoculation of Trichomonas culture in experimental animals and female breast diseased by fibrocystic mastopathy, the detection of Trichomonads was undertaken in surgically removed diseased breast parts. In 12 FCM patients, subjected to segmental breast resection, the imprint smears were prepared from dissected specimens and after supravital staining immediately examined by light microscopy. The mucous content from dilated ducts was inoculated in the culture media. The dissected tissues have been further histologically analysed by standard method. In nine out of 12 examined FCM cases the direct microscopy revealed aflagellary, pseudocystic, leucocytoid form of Trichomonads. The cultures were positive in 4 cases: in 3 patients Trichomonas tenax was identified and in the last one T vaginalis. Histopathological findings in all 12 examined cases have shown the changes characteristic for FCM. On the basis of the accumulated knowledge about pathogenic capacity of Trichomonads, it can be with great certainty claimed that these protozoa, even in their pseudocystic form are able to cause the all appearances characteristic for FCM. This first report about Trichomonas infection in the middle of FCM process gives the unexpected hope in solving of its etiology and new insight into antitrichomonal host reaction which is frequently associated with epithelial dysplasia and unrarely with precancerous lesions as earlier observed in cervix uteri.     

The trigemino-pupillary response in cluster headache

Central impairment of the integrative neural systems controlling vegetative function and pain perception has been demonstrated in cluster headache (CH). Recently, we described the human pupillary response (trigeminal reflex) to quantified (painless and painful) corneal stimulation with a combined neurophysiological and pharmacological technique. In this study, the trigeminal reflex was evaluated in 26 subjects with episodic cluster headache. During the active phase of the disease, on the side of the pain we observed reduced mydriasis to electrical stimuli with an intensity equal to the corneal reflex threshold, and on both sides to stimuli with intensity that equalled the pain threshold. No difference was found when amplitude of the miotic phase was compared in the different groups. These suggest disordered pupillary activation in response to pain, probably sympathetic in origin, which is bilateral, detectable also during the remission phase and which cannot be explained simply by the antidromic release of pain-related peptides.     

Behaviour during a cluster headache

Because cluster headache is short-lasting and tends to occur during the early morning hours, physicians rarely witness an attack. Accurate diagnosis is important because effective treatments are available. The diagnosis is made from the history of temporal pattern, reddening and tearing of the affected eye, and ipsilateral nasal congestion. An additional diagnostic aid is to invite patients to demonstrate how they respond to attacks. The pain, one of the worst known, causes extreme restlessness. 50 patients showed how they walk around, sit (or kneel) and rock, and clutch the affected side of the head. Diagnostic value apart, the patient will often be relieved to learn that bizarre behavioural responses are not a mark of insanity.     

Age-related ocular blood flow changes

PURPOSE: Pulsatile ocular blood flow (POBF is influenced by well-known parameters, such as intraocular pressure (IOP), heart rate, scleral rigidity, blood pressure, and posture. Age is also likely to influence POBF strongly. The purpose of this study was to evaluate POBF in relation to age in normal subjects. METHODS: Relevant data were collected from a sample of 105 normal subjects, ranging in age from 10 to 80 years. To measure the effect of age on POBF, the subjects were divided into seven groups of 15 subjects each; the age range of each group spanned one decade, beginning with age 10. POBF and pulse amplitude (PA) were measured in sitting and supine positions and after suction cup application. RESULTS: Using linear regression analysis, there was a significant correlation between PA and age in the supine position (P = 0.012) and after suction cup application (P = 0.002); in the sitting position, there was a borderline level of statistical significance (P = 0.053). In the sitting position, POBF was 819 +/- 212 microliters/minute in the second decade and 630 +/- 194 microliters/minute in the eighth decade. In the sitting position and after suction cup application, but not in the supine position, a statistically significant correlation between POBF decrease and age was found with linear regression analysis (P < 0.001 and P = 0.004, respectively). Using multiple regression analysis, POBF values revealed a significant correlation with age (P < 0.001), but not with systolic and diastolic brachial pressure. Considering all the subjects, analysis of variance for repeated measures highlighted a significant decrease of POBF from the sitting to the supine position and associated with an IOP increase (P < 0.001) without significant changes of PA. After suction cup application, there was a significant reduction of both PA and POBF (P < 0.001). CONCLUSIONS: The data revealed that as age increased, PA decreased in all three series of measurements. POBF decreased with age, and in subjects older than 50 years, the decrease was more evident. These findings are especially noticeable after IOP increase with suction cup. It must be considered that the age-related value of POBF is a fundamental parameter to evaluate correctly the hemodynamic aspects of the pathologies affecting the eye.     

Natural history of cluster headache

A follow-up study of 123 patients with episodic cluster headaches and of 9 patients with chronic cluster headaches was undertaken after 10-25 years, (mean 14.7 and 13.9 years respectively). This shows a significant but low remission rate for both episodic and chronic cluster headache. It confirms the observation that some patients change from episodic to chronic pattern, and that occasionally chronic clusters may become episodic.     

Cerebral blood flow in single and multiple lacunar infarctions

BACKGROUND AND PURPOSE: Single and multiple lacunar infarctions may have some difference in underlying diseases and cerebral blood flows. To determine the difference, we investigated underlying diseases and cerebral blood flows in single and multiple lacunar infarctions. METHODS: Fifteen cases of lacunar infarction, 10 cases of multiple lacunar infarctions, and 16 control subjects were studied. Regional cerebral blood flow was measured within 14 days after stroke onset with the stable xenon CT method. RESULTS: The rate of association of diabetes mellitus was higher in the multiple lacunar infarctions group than in the single lacunar infarction group. The blood flow in the cerebral cortex was significantly lower in the multiple lacunar infarctions group than in the single lacunar infarction group. The blood flow change by acetazolamide in the cerebral cortex was significantly lower in the multiple lacunar infarctions group than in the single lacunar infarction group. CONCLUSIONS: There is some difference in underlying diseases and cerebral blood flows between single and multiple lacunar infarctions.     

Cerebral blood flow and energy metabolism in the newborn

In normal newborn term and preterm infants CBF is relatively low corresponding to a low metabolic rate for oxygen, whereas cross-brain oxygen extraction is similar to that in adults. This provides for a considerable reserve capacity to deal with decreased CBF or decreased oxygen content in arterial blood. CBF reactivity to CO2 is normal, and the evidence is that pressure-flow autoregulation is present, even in very preterm infants. Absence of autoregulation and CBF-CO2 reactivity has been documented in severely asphyxiated infants, and in preterm infants who went on the develop severe intracranial hemorrhage. A number of methods are available to study CBF and brain metabolism in newborn infants. Several of them involve ionizing radiation, which has limited their use, even though it is unlikely that the associated risks are particularly high. Magnetic resonance spectroscopy has demonstrated a delayed disturbance of energy metabolism following severe asphyxia. Doppler ultrasound has rarely been helpful to obtain quantitative data. Near infrared spectrocopy has now been in use for more than 10 years. It has been slow to fulfill its promise as a continuous monitor of cerebral circulation and of oxygen sufficiency of neurons.     

Premonitory and prodromal symptoms in cluster headache

Warning symptoms in 150 cluster headache patients were studied by focusing on attacks occurring during waking hours. Warnings were divided into prodromes that started minutes before the pain of individual attacks (122 patients) and premonitory symptoms preceding the onset of cluster periods by days to weeks (12 patients). Pathogenetic and therapeutic implications are discussed.     

Cerebral blood flow study using SPECT in patients with memory disorders

INTRODUCTION: Global amnesia (AG) is a dysfunction of memory, in which there is a sudden incapacity to remember recent events and assimilate new information. The aetiology is currently under discussion. The main hypotheses under consideration are an ischemic mechanism and an epileptic mechanism. OBJECTIVE: To study the cerebral blood flow in patients with temporary global amnesia (AGT) or permanent global amnesia (AGP) using functional neuroimaging techniques. MATERIAL AND METHODS: Four patients were studied. Two had severe alterations of fixation memory which had been present for months. The other two had a sudden loss of recent memory, although space-person orientation and immediate memory remained normal. In all cases the cerebral blood flow (FSC), was assessed by single photon emission tomography (SPECT), using Tc-HMPAO as the radio tracer. RESULTS: We describe 4 patients, 2 men and 2 women aged between 42 and 64.2 with AGT and the others with AGP. On SPECT there was temporal hypoperfusion in all 4 patients. In 2 cases there was associated parietal hypoperfusion and in 1 case there was frontal hypoperfusion. CONCLUSIONS: These findings suggest that AGT and AGP are of vascular origin and that SPECT is a useful diagnostic technique in patients with AG.     

Cerebral blood flow velocity decreases during cognitive stimulation in Huntington's disease

OBJECTIVE: To examine whether activation of cerebral blood flow velocity during cognitive stimulation, as measured by transcranial Doppler ultrasonography (TCD), is altered in patients with Huntington's Disease (HD). BACKGROUND: Previous research suggests that resting cerebral blood flow in symptomatic and asymptomatic HD patients is reduced from expected premorbid levels. The effects of cognitive activation on this relative hypoperfusion in HD has not been studied extensively. METHODS: We measured TCD flow velocity during rest and cognitive testing with the Porteus Maze Test and the Trails Test in 12 normal control subjects and 10 gene-positive HD patients. Percent change (i.e., flow during testing/resting) of flow velocity in the anterior and middle cerebral arteries were compared between groups. Correlations among percent flow velocity change, a disability rating scale, and cognitive test scores were calculated. RESULTS: In control subjects, anterior cerebral artery flow velocity and middle cerebral artery velocity increased during cognitive testing (p=0.001). HD patients showed a smaller blood flow velocity increase in the anterior cerebral arteries during the Porteus Maze Test (p < 0.001) and the Trails Test, Part B (p < 0.001). In the left anterior cerebral artery, flow velocity fell an average of 4.2% below resting baseline levels during the Porteus Maze Test, and 1.2% below resting levels during the Trails Test. The magnitude of the cerebral blood flow velocity changes in the anterior cerebral artery correlated with a number of cognitive test scores and with a rating scale of functional disability. In addition, logistic regression was able to discriminate the HD patients from the control group based on blood flow velocity changes (p=0.0025). When HD patients were divided into more (i.e., HD with chorea; n=4) and less impaired (i.e., without chorea; n=6) groups, both showed significant decreases in left anterior cerebral artery flow velocity during visual spatial executive cognition testing compared with control subjects. CONCLUSIONS: These results suggest that activation of visual spatial executive functions cause decreased flow velocity in the anterior cerebral artery, but not the middle cerebral artery, in HD patients. These changes are related to test performance and functional capabilities.