G. Ebinger

S-100 protein as early predictor of regaining consciousness after out of hospital cardiac arrest.

BACKGROUND AND PURPOSE Patients resuscitated from cardiac arrest (CA) have a high mortality rate. Prognostic evaluation based on clinical observations is uncertain and would benefit from the use of biochemical markers of hypoxic brain damage. The purpose of the study was to validate the use of the serum astroglial protein S-100 levels at admission with regard to regaining consciousness after out of hospital CA. METHODS Fifty-eight patients resuscitated from out-of-hospital CA were followed up until they regained consciousness or until their death or permanent vegetative state occurred. Serum samples for measurement of S-100, using an immunoradiometric assay, were obtained at admission. RESULTS At admission, the mean value+/-standard error of the mean of serum S-100 protein was significantly higher in patients who did not regain consciousness compared with patients who regained consciousness, respectively 4.66+/-0.61 microg/l and 0.84+/-0.21 microg/l. A serum S-100 value of >0.7 microg/l at admission was found to be a predictor that consciousness would not be regained, with a specificity of 85%, a sensitivity of 66.6%, a positive predictive value of 84%, a negative predictive value of 78% and an accuracy of 77.6%. CONCLUSIONS Serum S-100 protein at admission gives reliable and independent information concerning the short term neurological outcome after resuscitation; and could be a good marker of brain cell damage.

Biotransformation of locally applied L-dopa in the corpus striatum of the hemi-Parkinsonian rat studied with microdialysis

Microdialysis was used to study the biotransformation of l-dopa in intact and denervated striata of rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra. Microdialysis probes were placed in the intact and in the denervated striatum. Observations were then made on freely moving rats. Extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid; HVA) were monitored before, during and after the local administration of l-dopa via the microdialysis probe for 20 min.A dose-dependent increase in extracellular dopamine levels was seen in intact striatum after application of l-dopa in concentrations ranging between 100 nmol/l and 10 μmol/l. In the denervated striatum, the severity of the lesion influenced dopamine formation, so that no dose-effect relation could be established.The effects of the continuous intra striatal infusion of nomifensine, tetrodotoxin or benserazide on the l-dopa-induced dopamine outflow revealed that in the intact striatum this dopamine release is mainly voltage dependent. It was concluded that in the denervated striatum other cells of non-neuronal origin and containing aromatic l-amino acid decarboxylase make a major contribution to the increase in extracellular dopamine levels. Furthermore, l-dopa itself shows no dopamine-releasing properties, at least under the present experimental conditions.

Biotransformation of L-DOPA in striatum and substantia nigra of rats with a unilateral, nigrostriatal lesion : a microdialysis study

SummaryMicrodialysis was used to study the biotransformation of l-DOPA in the striatum and substantia nigra of rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra. The animals were pretreated with carbidopa (50 mg/kg p.o.) for 5 days. They were anaesthetized, and microdialysis probes were implanted into the intact and denervated striatum and into the intact and lesioned substantia nigra. The biotransformation of l-DOPA (5 mg/kg i.p.) in these regions was investigated. These results were compared with those obtained after administration of a much higher dose of l-DOPA (100 mg/kg i.p.). Changes in extracellular l-DOPA, 3-O-methyldopa (3-OMD), dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined by HPLC with electrochemical detection.Although rats with a unilateral nigrostriatal lesion did not show rotational behaviour after 5 mg/kg l-DOPA, DA levels were increased significantly both in the intact and the denervated striatum and in the intact and the lesioned substantia nigra. This increase was most pronounced in the denervated striatum. At 100 mg/kg l-DOPA, the increases in extracellular dopamine in intact and denervated striatum were about twice as high as the increases observed at the lower dose. A similar increase was observed in the intact substantia nigra. However, in the lesioned substantia nigra there was a fourfold increase. l-DOPA, at both doses, was evenly distributed between the brain areas studied and the lesion had no effect on the uptake of the drug at the blood-brain barrier.Our data suggest that l-DOPA in the substantia nigra might play a role additional to that in the striatum in relieving symptoms of Parkinsons disease. Even at a low dose (5 mg/kg i.p.), the drug had an effect on extracellular dopamine in all the brain regions studied.

Thrombocytosis and ischaemic complications in giant cell arteritis.

Patients, methods, and results We reviewed the medical records of patients with a diagnosis of giant cell arteritis who were admitted to the University Hospital of the Vrije Universiteit Brussel between 1984 and 1989. The diagnosis was based on clinical features, laboratory data (raised erythrocyte sedimentation rate), biopsy findings in temporal arteries, good response to corticosteroid treatment, and subsequent course. The study population consisted of 56 patients (31 women, 25 men) aged 60-89 years (mean 75-6 (SD 6 3)). Platelet count was determined as routine with an automated counter (normal range 150-400x 10O/l) before corticosteroid treatment. Patients were assigned to one of two groups based on the presence or absence of transient or permanent visual loss, transient cerebral ischaemic attack, or stroke. Age and sex distributions of the groups were similar (table). Eighteen patients (32%) had a history of ischaemic complications. Transient or permanent visual loss occurred in 13, transient cerebral ischaemic attacks in seven (all in the vertebrobasilar system), and stroke in two (one patient died from a brain stem infarction and the other had an infarction in the territory of the middle cerebral artery). In the whole study population thrombocytosis

Distribution of monoamines in human brain evidence for neurochemical heterogeneity in subcortical as well as in cortical areas

Norepinephrine, epinephrine, dopamine, serotonin and their major metabolites were measured by high-performance liquid chromatography with electrochemical detection in 49 regions of the human brain. The regional distribution of the different monoamines in the subcortical areas was similar to previous reports. We report here the distribution pattern of the 4 monoamines observed in the cerebral cortex. Regional differences in concentration were observed for norepinephrine, epinephrine and serotonin, with high concentrations in the frontal and parietal regions. However, no regional difference in dopamine concentrations was detected. The possible role of norepinephrine and serotonin as conventional transmitters, and of dopamine and epinephrine as neurotransmission modulators is discussed.

Sudden hypotonic paraparesis caused by tophaceous gout of the lumbar spine

Gouty arthritis of the axial skeleton is rare, and neurological complications due to spinal cord or nerve root compression secondary to tophaceous deposits have been seldom reported. We describe a patient with chronic gouty arthritis who developed an acute paraparesis caused by tophaceous cauda equina compression. Surgical removal of the mass resulted in complete recovery.

The mesoneocortical dopamine neuron system.

The ascending dopaminergic projections from the midbrain have been subdivided into a nigrostriatal and a mesocorticolimbic ~ornponent.’-~ The neuronal cell bodies are located in the substantia nigra and ventral tegmental area. The axons of the nigrostriatal neurons terminate in the caudate nucleus, putamen, and globus pallidus. A reduction of the dopaminergic neurotransmission in the nigrostriatal pathway gives rise to parkinsonism. A hyperactivity of this system has been implicated in other movement disorders, such as Huntington’s chorea. The term “mesocorticolimbic” is used to designate projections to the nucleus accumbens, amygdala, septal nuclei, olfactory tubercle, and certain cortical areas. It has been hypothesized that an overactivity of this system plays a role in the symptomatology of psychotic disorders, whereas a reduced function might contribute to the cognitive abnormalities found in patients with Parkinson’s disease. Because part of the neurons projecting to the striatum also arise from the ventral tegmental area, some authors prefer the term “mesostriatal” instead of “nigrostriatal,” and the projection to the nucleus accumbens has been included under this system as we112 The mesocorticolimbic system is often referred to as the “mesocortical” system (the nucleus accumbens being excluded).2 Within the mesocortical system, one distinguishes allocortical and neocortical projections. The allocortical axons terminate in phylogenetically old cortical derivates, such as the olfactory tubercle, amygdala, septal nuclei, and piriform cortex, as distinct from the neocortical areas, which this review will cover.

Recurrent forms of sporadic brachial plexus neuropathy. A report of two cases

Two patients presenting a relapsing form of sporadic brachial plexus neuropathy, the so-called Parsonage Turner syndrome, are reported. The diagnosis is based on clinical and electromyographic features. Recurrent attacks, although infrequently encountered, have been well described in the past. Sporadic cases of this syndrome must be differentiated from the familial varieties of neuralgic amyotrophy in which, two main subgroups of patients are distinguished: those showing facial dysmorphic features and those with findings of a tomaculous neuropathy predisposing them to pressure palsies. Apart from the obvious difference as regards familial occurrence, the familial and non-familial varieties of neuralgic amyotrophy differ in a number of respects: associated congenital defects, early age of onset and high rate of recurrence in the former. Finally some possible pathogenetic mechanisms of the syndrome are briefly reviewed.

Brain stem infarction as a complication of giant-cell arteritis

Two cases of brain stem infarction as an early and fatal complication of giant-cell arteritis are reported. These complications occurred despite adequate treatment with corticosteroids. The findings at autopsy are compared with those of the literature. The possible pathogenetic mechanisms of vertebro basilar occlusion and the therapeutical implications are discussed.

Enophthalmos as a rare manifestation of metastatic orbital involvement.

Two cases in which orbital metastasis produced enophthalmos, instead of the usual exophthalmos, are reported. Only fourteen other cases have been described previously and they are reviewed. At time of diagnosis of the enophthalmos, meningeal carcinomatosis coexisted in the first case and probably also in the second case. This association can lead to diagnostic errors with either the orbital metastasis or the meningeal carcinomatosis being missed. In addition, as in our second case, the enophthalmos can be the initial manifestation of cancer.