[A peculiar mechanism of hydrocephalus: the "water-hammering" effect].

Background And Purpose: Aneurysms of the basilar artery can cause hydrocephalus due to compression of the third ventricle or the sylvian aqueduct. The observation of a particular case led to discuss another possible mechanism of hydrocephalus.

Clinical Presentation And Radiological Studies: An aneurysm of the basilar artery was revealed by an ischemic stroke in a 65-year-old man.

[Late cerebral radionecrosis of cystic aspect].

Two cases of delayed cerebral radionecrosis with cystic presentation are reported. The patients had received radiation therapy for a cutaneous tumor 16 and 12 years before. Surgical extirpation of the cerebral lesion permitted to confirm the diagnosis and to treat the patients with success.

[Spasmodic laughter caused by unilateral involvement of the brain stem].

We report a case of spasmodical laughter due to a strictly unilateral lesion located in the pons and the caudal part of the mesencephalon. Pathophysiology of this particular symptom is reviewed.

Age and cerebral infarction: a postmortem study of 77 cases of cerebral infarcts in the middle cerebral artery territory.

Adverse effect of age on ischemic stroke short-term mortality was reported in some studies and attributed either to more frequent extracerebral causes of death or to an increased severity of ischemia in the aged brain. Relationship between age, size of infarcts, and causes of death were studied in 77 consecutive patients who died from infarction in the middle cerebral artery territory. Area of infarcts was assessed by planimetry, and results were expressed as an index of infarcted area.

Infarcts in the middle cerebral artery territory. Pathological study of the mechanisms of death.

Correlates of the size of infarcts, the time from stroke to death, and the mechanisms of death were studied in 77 consecutive patients who died from infarction in the middle cerebral artery territory. The area of infarcts was assessed by planimetry on schemas of representative brain levels and the results were expressed as a ratio of infarcted area on the whole MCA territory. No clear relationship was found between the size of infarcts in the MCA territory, and any of the characteristics of the patients, but extensive infarcts were more frequent when the internal carotid artery was occluded.

[Effect of diabetes mellitus and blood glucose on the size of cerebral infarction and causes of death. Neuropathological study of 77 cases of infarction in the sylvian artery area].

The influence of diabetes mellitus and hyperglycemia on cerebral infarction has been studied on 77 patients who died of infarcts in the territory of the middle cerebral artery. The size of the infarcts was assessed by transferring the surface of the infarcted area onto 8 schematic drawings corresponding to 8 brain slices and measuring this surface by means of a planimeter. An infarction volume index (IVI) was calculated by measuring the ratio of the infarcted area to the theoretical area of the middle cerebral artery territory on the 8 slices.

Positron emission tomography study in progressive supranuclear palsy. Brain hypometabolic pattern and clinicometabolic correlations.

In 41 patients with progressive supranuclear palsy (PSP) that was diagnosed on the basis of eight clinical criteria (25 patients with all eight criteria [probable PSP] and 16 with six or seven criteria [possible PSP]), we studied cerebral energy metabolism by using positron emission tomography and the fludeoxyglucose F 18 or the oxygen 15 method. Compared with age-matched controls, each of the cortical and subcortical metabolic values was significantly reduced, with a predominance in the frontal cortex, in both groups of patients with probable and possible PSP, without a difference between these two groups, suggesting similar underlying disease. The frontal metabolic value decreased with disease duration, but the relative frontal hypometabolism (expressed as the fronto-occipital metabolic ratio) was apparently already present in the early stages of the disease.

Effects of capsular or thalamic stroke on metabolism in the cortex and cerebellum: a positron tomography study.

We used positron emission tomography to study the cortical and cerebellar metabolic rates in 21 strictly selected patients with pure internal capsular infarct (n = 8), thalamocapsular hemorrhage (n = 6), or pure thalamic stroke (n = 7). Significant diffuse ipsilateral cortical hypometabolism relative to 62 controls free of cerebrovascular risk factors was frequently, although not consistently, found in the 13 patients with thalamocapsular or thalamic lesions and neuropsychological impairment but was absent from the eight patients with pure internal capsule infarct and free of neuropsychological deficit. These data suggest that damage to the thalamus or the thalamocortical projections is important in the development of ipsilateral cortical hypometabolism and that the latter may underlie the associated neuropsychological impairment.

[Subacute brainstem hematoma. A surgically treated case].

We report a case of pontine haemorrhage in which symptoms and signs developed over a 2-months period. Surgery was successful but the patient subsequently died. The pathophysiology of subacute and chronic symptoms and signs is discussed.

Striatal dopamine D2 receptors in tardive dyskinesia: PET study.

The dopamine D2 receptors were investigated in vivo in eight neuroleptic-free patients with persistent tardive dyskinesia using positron emission tomography and 76Br-bromospiperone. The striatal receptor density, estimated by the striatum/cerebellum radioligand concentration ratio, was not elevated in patients as compared with age-matched controls but was positively correlated with the severity of orofacial dyskinesia assessed with the Abnormal Involuntary Movement Rating Scale. These results indicate that tardive dyskinesia is associated with normal levels of striatal D2 receptors but the severity of orofacial movements may depend on the relative density of striatal D2 receptors.

SPECT analysis of recent cerebral infarction.

We measured regional cerebral blood flow and [123I]iodoamphetamine (IMP) uptake in 16 patients with unilateral brain infarcts during the subacute period (Day 3 to Day 50) and again after 3 months. Our results show that the central and peripheral areas described earlier in the chronic period were already differentiated in the subacute period. The central area presented a short phase of luxury perfusion and a longer phase of IMP hyperfixation.

Striatal dopamine receptor occupancy during and following withdrawal from neuroleptic treatment: correlative evaluation by positron emission tomography and plasma prolactin levels.

The percentage occupation of striatal dopamine D2 receptors has been evaluated in 25 patients using 76Br-bromospiperone positron emission tomography (PET) and prolactin plasma levels (PRL) during oral neuroleptic treatment (11 studies), 1-90 days following discontinuation of such treatment (16 studies), and 1-120 days after last intramuscular administration of depot neuroleptics (nine studies). The PET-estimated occupation was highly significantly correlated in a sigmoid-like fashion to the logarithm of the chlorpromazine-equivalent dose of oral neuroleptics (suggesting a strict dose-occupation relationship during oral neuroleptic treatment and supporting the D2-mediated hypothesis of neuroleptic action), while PRL was weakly related to daily dosage. Following withdrawal, return to normal receptor availability, as estimated by PET, occurred within 5-15 days (suggesting that protracted effects of neuroleptics after withdrawal are not due to sustained D2 receptor occupation), but PRL values fell even more rapidly.

Cortical hypometabolism and its recovery following nucleus basalis lesions in baboons: a PET study.

The cerebral metabolic rate for glucose was measured serially with positron emission tomography and [18F]fluorodeoxyglucose in five baboons with stereotactic electrocoagulation of the left nucleus basalis of Meynert (NbM). Four days after lesion, a significant metabolic depression was present in the ipsilateral cerebral cortex, most marked in the frontotemporal region, and which recovered progressively within 6-13 weeks. These data demonstrate that adaptive mechanisms efficiently compensate for the cortical metabolic effects of NbM-lesion-induced cholinergic deafferentation.

In vivo assay for neuroleptic receptor binding in the striatum. Positron tomography in humans.

Using PET, we investigated the potency in six patients of therapeutic doses of neuroleptic drugs for preventing specific binding of trace doses of intravenously administered 76Br-labelled bromospiperone to corpus striatum in vivo. Measured receptor occupancy showed a clear-cut dose-dependent saturation curve with increasing daily oral dose of neuroleptics, indicating the validity and reliability of the method when used as an in vivo radioreceptor assay. Following drug withdrawal in eight patients, recovery to normal or supranormal receptor availability occurred in a matter of days.

[Focal chronic ischemia and concomitant migraine: an atypical form of Sturge-Weber angiomatosis?].

A young man with a left hemifacial hemangioma had during a six months period about forty left hemispheric neurologic attacks suggestive of classic migraine. The neurologic examination was normal during the attack-free period. The CT scan (fig.

Remote metabolic effects of cerebrovascular lesions: magnetic resonance and positron tomography imaging.

Combined Positron Emission Tomography (PET) and Proton Magnetic Resonance Imaging (MRI) study were performed in six patients with chronic supratentorial stroke to investigate whether remote hypometabolic regions revealed by PET showed any abnormality on MRI. Either regional oxygen consumption (n = 4) or glucose utilization (n = 2) were measured using PET and the 15O steady state 18FDG technique, respectively. Four patients, with deeply located brain lesions, showed a significant metabolic reduction in the overlying cerebral cortex.

Loss of striatal [76Br]bromospiperone binding sites demonstrated by positron tomography in progressive supranuclear palsy.

Using positron tomography and 76Br-labeled bromospiperone, a neuroleptic drug with high affinity for the dopamine (DA) receptors, we have estimated the specific binding of the radiotracer to striatal DA receptors in seven patients suffering from progressive supranuclear palsy. Compared with age- and sex-matched control subjects, we found a significant (p less than 0.02) decrease of the striatum-cerebellum uptake ratio in progressive supranuclear palsy patients, suggesting loss of striatal DA receptors.

In vivo quantitative imaging of dopamine receptors in human brain using positron emission tomography and [76Br]bromospiperone.

The brain regional distribution and kinetics of [76Br]bromospiperone, a derivative of a neuroleptic (spiperone) labeled with the positron emitter bromine-76, were studied by time-of-flight tomography after i.v. injection in man.