Neuron-specific enolase and S-100 protein levels in cerebrospinal fluid of patients with various neurological diseases

Neuron-specific enolase levels in the cerebrospinal fluid of neurologically healthy children

Levels of neuron-specific enolase (NSE) levels in the cerebrospinal fluid (CSF) of children without neurological disease were assessed. CSF samples were obtained from 37 subjects aged between 1 month and 13 years. All subjects had undergone lumbar puncture for diagnostic purposes, and were subsequently shown not to be suffering any form of neurological disease. NSE levels in CSF were determined by an enzyme immunoassay method. NSE level ranged from below the detection limit to 4.8 ng/ml (1.52+/-1.01 ng/ml). The present results may be useful as a basis for defining reference levels of NSE in CSF in post-neonatal children.

Evaluation of serum markers of neuronal damage following severe hypoglycaemia in adults with insulin-treated diabetes mellitus

BACKGROUND

Neurone-specific enolase (NSE) and protein S-100 (S-100) may be used as markers of acute neuronal damage in humans with neurological disorders.

METHOD

To evaluate their use following a single episode of severe hypoglycaemia (defined as an episode requiring external assistance to aid recovery), serum concentrations of NSE and S-100 were measured following hypoglycaemia which had not caused persistent neurological impairment in 16 patients with insulin-treated diabetes (the 'hypo' subjects), and in three diabetic patients who died following severe hypoglycaemia. The serum proteins were also measured in 10 subjects with insulin-treated diabetes who had not experienced an episode of severe hypoglycaemia within the preceding year (the 'control' subjects).

RESULTS

No differences in serum concentrations of NSE and S-100 were observed between the 'control' and the 'hypo' subjects at either 36 hours or seven days after the episode of severe hypoglycaemia (p>0.05). However, in two of the three subjects who died following hypoglycaemia, serum concentrations of the markers were markedly elevated.

CONCLUSIONS

Any neuronal injury occurring during severe hypoglycaemia that is not associated with persistent neurological deficit is insufficient to provoke elevation of these serum markers. However, the measurement of serum concentrations of NSE and S-100 may have a prognostic role in evaluating clinical outcome following severe hypoglycaemia which is associated with neurological damage.

Diagnosis of Creutzfeldt-Jakob disease and related human spongiform encephalopathies

Spongiform encephalopathies are transmissible diseases (TSE) of animals and humans. With the appearance of bovine spongiform encephalopathy (BSE) in 1986 and in 1996 with the identification of an apparently new variant of the human spongiform encephalopathy Creutzfeldt-Jakob disease (CJD), great concerns of a potential transmission of BSE to humans have been voiced. The agent known to transmit CJD and other human and animal spongiform encephalopathies is designated as prion, i.e., proteinaceous infectious agent, due to the absence of evidence for the involvement of a nucleic acid in disease transmission. In humans the clinical diagnosis of typical CJD cases can now be supported by paraclinical parameters. Electroencephalographic changes, so called periodic sharp wave complexes, are pathognomonic for CJD but by no means specific. The detection of neuronal enzymes in the cerebrospinal fluid (CSF) such as neuron specific enolase (NSE) or glial proteins such as S-100 aids greatly in the diagnosis of a human spongiform encephalopathy. By far the most specific marker in CSF are a group of proteins designated 14-3-3. Current evidence suggests that by including elevated levels of NSE (> or = 35 ng/mL), S-100 (> or = 8 ng/mL) and tau protein in the CSF and the presence of 14-3-3, a laboratory supported diagnosis of CJD can be achieved which in the appropriate clinical setting has a better diagnostic accuracy than the currently used clinical and paraclinical diagnostic criteria alone.

Cerebrospinal fluid markers in multiple sclerosis: an overview

Cerebrospinal fluid (CSF), with its protein markers, is a formidable material for investigating the relationships among the various cell types involved during the initial phase of plaque formation, or, successively, in the remyelination process. Its analysis may give definite help in better focusing on therapeutic objectives and therapeutic tools. Therefore, the possible use of CSF MBP, S-100, GFAP, N-CAM, NGF, and CNTF in pathogenetic studies and in clinical follow-up is critically reviewed. The need for correct interpretation of the data, for uniformity and reliability of the analytical methods, and for easy access to them is stressed. CSF examination and MRI should not be considered as alternative tools, or in competition, but should be used together, to take the maximum advantage of their individual possibilities.

Detection of 14-3-3 protein in the cerebrospinal fluid supports the diagnosis of Creutzfeldt-Jakob disease

The analysis of 14-3-3 protein in cerebrospinal fluid (CSF) was shown to be highly sensitive and specific for the diagnosis of Creutzfeldt-Jakob disease (CJD). However, the predictive value of this test in the clinical diagnosis of, and its relation to, sporadic, genetic, and iatrogenic CJD cases have yet to be established. CSF samples of suspect CJD cases seen in the prospective German surveillance study were tested for the presence of 14-3-3 protein by using a modified western blot (WB) technique. WB detected 14-3-3 protein in 95.4% of definite and 92.8% of probable cases. In two patients classified initially as not having CJD the test was positive, and both were later proved to have definite CJD. The positive predictive value is 94.7% and the negative predictive value is 92.4%. False-positive results in a single CSF analysis were seen in patients with herpes simplex encephalitis, hypoxic brain damage, atypical encephalitis, intracerebral metastases of a bronchial carcinoma, metabolic encephalopathy, and progressive dementia of unknown cause. WB analysis for 14-3-3 protein was positive in only 5 of 10 cases of familial forms of spongiform encephalopathies. CSF analysis for 14-3-3 protein should thus be performed in any case suspect for CJD.

Increased S100beta in the cerebrospinal fluid of patients with frontotemporal dementia

Levels of S100beta, a calcium-binding protein found in astrocytes, were measured using a sandwich ELISA in the cerebrospinal fluid (CSF) of patients with frontotemporal dementia and Alzheimer's disease and compared with controls. Mean CSF S100beta concentrations were significantly raised in patients with frontotemporal dementia when compared with healthy controls (0.49 +/- 0.28 vs. 0.22 +/- 0.08 ng/ml, P < 0.001). There was no correlation between age at disease onset, disease severity or length of illness. The increased concentration of CSF S100beta seen in frontotemporal dementia may reflect the marked astrocytosis seen in this condition.

Cerebrospinal fluid analysis differentiates between relapsing-remitting and secondary progressive multiple sclerosis

OBJECTIVES

To find whether CSF analysis may differentiate between relapsing-remitting and secondary progressive multiple sclerosis.

METHODS

In 17 patients with relapsing-remitting and 16 patients with secondary progressive multiple sclerosis, all without current or recent relapses, albumin CSF: peripheral blood ratio, mononuclear cell number, CD4+, CD8+, and B1+ subsets, CD4+:CD8+ ratio, IgG, IgG index, IgM, IgM index, complement components C3 and C4, and C3 and C4 indices, myelin basic protein, neuron specific enolase, S100, and lactate were determined. For each measure the statistical distance measure D2 was calculated. For computation of a discriminant score variables with a P value< or =0.15 were included (two sided univariate t test). These were albumin CSF: peripheral blood ratio, mononuclear cell number, IgM, IgM index, C3, C4, neuron specific enolase, S100, and lactate. Simultaneous distributions of the variables were compared between both groups (multivariate t test) and a discriminant score was computed (linear discriminant analysis).

RESULTS

The discriminant score allocated all 14 relapsing-remitting patients to the relapsing-remitting group (positive score) and 12 of 13 secondary progressive patients to the secondary progressive group (negative score). One secondary progressive patient was allocated to the relapsing-remitting group.

CONCLUSIONS

Patients with relapsing-remitting or secondary progressive multiple sclerosis differ in CSF profile and CSF analysis may help to differentiate between relapsing-remitting and secondary progressive multiple sclerosis.

S-100 protein: serum marker of focal brain damage after ischemic territorial MCA infarction

BACKGROUND AND PURPOSE

Elevations of protein S-100 (S-100) in cerebrospinal fluid and serum have been reported after cerebral infarctions. The aim of our study was to evaluate the time course of serum S-100 concentrations after territorial middle cerebral artery (MCA) infarctions in correlation with clinical data and prognosis.

METHODS

S-100 serum levels were serially determined in 26 patients with an acute infarction in the territory of the MCA at day 0 (within 12 hours after onset of symptoms), day 1 (24 hours after stroke onset), and days 2, 3, 4, 5, 7 or 8, and 10 after stroke and in 26 age- and sex-matched control subjects. S-100 assays were performed using a two-site radioimmunoassay technique. The clinical status was documented using the Scandinavian Stroke Scale. The functional deficit 4 weeks after stroke onset was scored by use of the modified Rankin scale. A cranial computed tomography (CCT) was performed initially and at day 4 or 5.

RESULTS

Elevated concentrations of S-100 (> 0.2 microgram/L) were observed in 21 of 26 patients with MCA infarction but in none of the control subjects. S-100 levels peaked at days 2 and 3 after stroke. The S-100 concentrations in serum were significantly higher in patients with severe neurological deficits at admission, with extensive infarctions and a space-occupying effect of ischemic edema as compared with the rest of the population. S-100 values were not significantly correlated with the functional prognosis.

CONCLUSIONS

Presence of S-100 in serum after ischemic stroke may be due to combined leakage out of necrotic glial cells and passage through an impaired brain-blood barrier, indicating severe ischemic cell injury. Therefore, S-100 in serum can be used as a peripheral marker of ischemic focal brain damage and may be helpful for therapeutic decisions in acute ischemic stroke.

Serum S-100 protein, relationship to clinical outcome in acute stroke

The clinical significance of serum S-100 protein, a protein released by damaged brain tissue, was assessed in patients with acute ischaemic or haemorrhagic stroke and matched controls. Serum S-100 protein concentration was significantly elevated in patients with ischaemic stroke [median (SQR): 0.27 (0.09) microgram/L, n = 68] and haemorrhagic stroke [0.43 (0.23) microgram/L, n = 13] compared to controls [0.11 (0.03) microgram/L, n = 51, P < 0.0001]. Although patients with haemorrhagic stroke had higher serum S-100 concentrations compared to patients with ischaemic stroke, this was not quite statistically significant. Serum S-100 concentrations were related to infarct size, large (total anterior circulation) infarcts concentrations having the highest [0.40 (0.22) microgram/L], and small vessel ('lacunar') infarcts concentrations having the lowest [0.20 (0.06) microgram/L, P < 0.0005] concentrations. S-100 protein concentration was also significantly related to clinical outcome at three months measured using three disability and handicap scales (n = 81): modified Barthel index (rs = -0.285, P = 0.01), modified Rankin score (rs = 0.313, P = 0.004) and Lindley score (rs = 0.262, P = 0.018) with high values associated with poor clinical outcome. Similarly high values of serum S-100 protein were observed in patients who died or were discharged to an institution [median (SQR): 0.63 (0.29) microgram/L and 0.37 (0.13) microgram/L, respectively] compared to those who were discharged home [0.26 (0.11) microgram/L, P = 0.13]. The present study suggests measurement of serum S-100 protein could be a useful prognostic marker of clinical outcome in acute stroke. Whether S-100 concentrations can be altered by therapeutic intervention in acute stroke remains to be elucidated.

Serum S-100 protein, relationship to clinical outcome in acute stroke

The clinical significance of serum S-100 protein, a protein released by damaged brain tissue, was assessed in patients with acute ischaemic or haemorrhagic stroke and matched controls. Serum S-100 protein concentration was significantly elevated in patients with ischaemic stroke [median (SQR): 0.27 (0.90) microgram/L, n = 68] and haemorrhagic stroke [0.43 (0.23 microgram/L, n = 13] compared to controls [0.11 (0.03) microgram/L, n = 51, P < 0.0001]. Although patients with haemorrhagic stroke had higher serum S-100 concentrations compared to patients with ischaemic stroke, this was not quite statistically significant. Serum S-100 concentrations were related to infarct size, large (total anterior circulation) infarcts concentrations having the highest [0.40 (0.22) microgram/L], and small vessel ('lacunar') infarcts concentrations having the lowest [0.20 (0.60) microgram/L, P < 0.0005] concentrations. S-100 protein concentration was also significantly related to clinical outcome at three months measured using three disability and handicap scales (n = 81): modified Barthel index (rs = -0.285, P = 0.01), modified Rankin score (rs = 0.313, P = 0.004) and Lindley score (rs = 0.262, P = 0.018) with high values associated with poor clinical outcome. Similarly high values of serum S-100 protein were observed in patients who died or were discharged to an institution [median (SQR): 0.63 (0.29) microgram/L and 0.37 (0.13) microgram/L, respectively compared to those who were discharged home [0.26 (0.11) microgram/L, P = 0.13]. The present study suggests measurement of serum S-100 protein could be a useful prognostic marker of clinical outcome in acute stroke. Whether S-100 concentrations can be altered by therapeutic intervention in acute stroke remains to be elucidated.

A specific and sensitive ELISA for measuring S-100b in cerebrospinal fluid

A sensitive, simple and specific sandwich ELISA for S-100b is described. This method involves the binding of a monoclonal anti-S-100b antibody to the wall of a microtitre plate. This capture antibody is subsequently incubated with S-100b standard, control or patient sample in the form of cerebrospinal fluid (CSF). After incubation, the microtitre plate is washed and horseradish peroxidase-labelled polyclonal anti-S-100b is added (detector antibody). The amount of detector antibody bound to the microtitre plate is proportional to the amount of S-100b in the sample. The assay has a lower limit of detection of 0.04 ng/ml and shows < 0.006% reactivity with the closely related polypeptide S-100a. The assay has a mean within-batch precision of 9.3 and 5.6% at S-100b concentrations of 0.38 and 0.8 ng/ml, respectively. The between batch precision is 8.9 and 8.1% at S-100b concentrations of 0.12 and 0.34 ng/ml, respectively. The recovery of S-100b from CSF spiked with 0.5 ng/ml was 94% with a CV of 8.5%. The assay may be completed in less than 5 h using precoated microtitre plates, thus lending itself to routine use in clinical laboratories. Using this ELISA, 154 CSF samples were analysed and 19% of samples were found to have elevated levels. The highest levels were found in patients with cerebral haemorrhage or central nervous system malignancy. S-100b concentrations from individuals without evidence of neurological disease were found to be less than 0.4 ng/ml. Only 5% of patients with multiple sclerosis were found to have elevated CSF S-100b concentrations. Serial CSF samples taken from a patient with an infected in-dwelling shunt showed a dramatic decline, suggesting that S-100b is rapidly cleared.

Neuropsychological function in patients with increased serum levels of protein S-100 after minor head injury

Protein S-100 is a calcium binding protein, synthetized in astroglial cells in all parts of the central nervous system (CNS). We have previously reported high serum levels of protein S-100 in patients after minor head injury (MHI). A battery of conventional and computerized neuropsychological measures was administered to two groups of MHI patients. Neuropsychological outcome at 12 months postinjury was examined in a group of 7 patients with increased serum levels of protein S-100 after MHI and 7 age- and sex-matched controls without detectable S-100 in serum after MHI. Our results demonstrate no overall cognitive dysfunction in either of the two groups. Our findings indicate specific dysfunction on measures of reaction time, attention and speed of information processing for the S-100 group. Posttraumatic depression does not explain the neuropsychological differences between the groups. These findings support that increased serum levels of protein S-100 may be of predictive and prognostic value for longlasting neurocognitive abnormalities after minor head injury. Presence of S-100 in serum may indicate the presence of diffuse brain damage. Our results suggest that information processing measures in computerized neuropsychological assessment are more sensitive for detecting small signs of neurocognitive abnormalities after MHI than conventional test batteries.

Serial S-100 protein serum measurements related to early magnetic resonance imaging after minor head injury. Case report

The authors studied 24 patients with a Glasgow Coma Scale score of 14 or 15 and normal computerized tomography scans after minor head injury. The study protocol included obtaining serial measurements of S-100 protein in serum during the first 12 hours after injury and early magnetic resonance (MR) imaging. Four patients (17%) had detectable levels of S-100 protein in serum. The S-100 protein levels were highest immediately after trauma, declining hour by hour. In two patients, MR imaging revealed intracranial contusion. Levels of S-100 protein were not detectable in serum in one patient with MR-verified cerebral contusion, but the first measurements were made late, 6 hours after trauma. The highest serum level of S-100 protein (0.9 microgram/L) was seen in a 73-year-old man 2 hours after injury. Magnetic resonance imaging revealed a contusion of the left cerebellar hemisphere, and the patient suffered permanent sequelae of impaired posture and dizziness.

Diagnosis of Creutzfeldt-Jakob disease by two-dimensional gel electrophoresis of cerebrospinal fluid

BACKGROUND

The diagnosis of Creutzfeldt-Jakob disease (CJD) is based on clinical and electroencephalographic criteria which do not allow a reliable diagnosis to be made during life.

METHODS

Serum and cerebrospinal fluid (CSF) samples were obtained after informed consent from relatives of suspected cases of CJD referred to the German CJD surveillance unit. CSF samples from 58 definite (neuropathologically verified), 46 probable, and 34 possible CJD cases, and from 44 patients without CJD were analysed by two-dimensional gel electrophoresis (2-DE). Two investigators blinded to clinical findings recorded the presence of two proteins, p130/131. The kappa value for the level of agreement between these investigators was calculated. Results obtained were compared with the determination of neuron-specific enolase (NSE) in CSF. NSE concentrations of more than 35 ng/mL were considered indicative of CJD.

FINDINGS

p130/131 was detected in 81% of definite (47/58), 80% of probable (37/46), 68% of possible (23/34) CJD cases, and in none of the other 44 cases. NSE concentrations of more than 35 ng/mL were seen in 79% of definite (46/58), 80% of probable (37/46), 59% of possible (20/34) CJD cases, and 9% of other cases (4/43). The positive predictive value for 2-DE of CSF is 100% and the negative predictive value is 69%. The level of agreement for the detection of p130/131 by two evaluators in a subset of 141 2-DE gels was a kappa of 0.93 (95% CI 0.86-0.99). Of 13 cases initially classified as possible and later reclassified as definite, ten cases were identified correctly by the 2-DE analysis, indicating a better diagnostic accuracy of this test compared with the current clinical classification. None of nine cases classified as other by neuropathology had p130/131 in 2-DE.

INTERPRETATION

2-DE for p130/131 is a specific test for the diagnosis of CJD. These data suggest including detection of p130/131 as a criterion for the diagnosis of probable CJD in addition to the currently accepted criteria of a rapidly progressive dementia of less than 2 years duration, typical neurological signs, and periodic sharp-wave complexes in the EEG.

Routine early CT-scan is cost saving after minor head injury

Significant hospital resources are invested in early detection of intracranial complications after minor head injuries (MHI). This study focuses on economic aspects of MHI management. 88 MHI patients underwent routine early CT-scan and at least 24 h in-hospital observation. The cost of this management was calculated, and compared to estimated costs of three alternative management protocols. CT-scans demonstrated intracranial lesions in eight (9%) patients, but none required neurosurgical intervention. The expense of our management was Norwegian Kroner (NOK) 576,136. An alternative management protocol including routing early CT-scan and discharge of patients with normal CT-findings, Glasgow coma score > or = 14 and no neurological deficits, was found to be safe, and estimated to reduce costs with 43% to NOK 326,669. It is concluded that routine early CT-scan is the most reliable and cost saving management procedure after MHI.

Clinico-pathophysiological features of acute autonomic and sensory neuropathy: a long-term follow-up study

We evaluated the clinico-pathophysiological features of three patients with acute autonomic and sensory neuropathy (AASN) who were followed for over 3 years. Signs of an autonomic disturbance including vomiting, anhidrosis, urinary disturbances, orthostatic hypotension and reduced coefficient of variation of the R-R interval on electrocardiography gradually improved about 1 year after onset. However, all three exhibited severe generalized sensory impairment for all modalities with the development of persistent sensory ataxia. No sensory nerve action potentials could be elicited and no somatosensory evoked potentials could be obtained. Sural nerve biopsy revealed severe axonopathy. In two patients, a high-intensity area was observed in the posterior column of the spinal cord on T2*-weighted axial magnetic resonance images. The level of neuron-specific enolase in cerebrospinal fluid was markedly elevated in two patients, indicating spinal nerve root or sensory neuron damage. Motor nerve function was well preserved in all patients. Our findings suggests that the major lesion in patients with AASN, particularly those with a sensory deficit, is present in the dorsal root ganglion neurons, that is there is a ganglioneuronopathy.

Measurement of S-100 protein in human blood and cerebrospinal fluid: analytical method and preliminary clinical results

An immunofluorometric sandwich assay for determination of S-100 protein in cerebrospinal fluid (CSF) and blood is described. The lower detection limit was 0.015 micrograms/l of S-100 protein. Intra-assay and inter-assay imprecision (coefficients of variation, CVs) were 2.1 to 3.2% and 7.8 to 11.6%, respectively. S-100 protein recovery in cerebrospinal fluid was 94 to 103%. In blood the recovery varied from 67 to 96%, depending on blood samples used and the concentration of S-100 protein. The best recovery in blood was found using heparinized plasma. In healthy subjects 0.098 +/- 0.11 micrograms/l (mean +/- SD) of S-100 protein was detected (n = 30). In the CSF of otherwise healthy patients undergoing a myelography for lumbar pain 1.43 +/- 0.49 micrograms/l (mean +/- SD) of S-100 protein was found. Preliminary results from longitudinal studies on S-100 protein in neurosurgical patients indicate a positive correlation between S-100 protein blood levels and clinical course. Thus, the determination of S-100 protein in blood appears to be helpful in the monitoring of patients with neuronal damage.

Cerebrospinal neuron-specific enolase, S-100 and myelin basic protein in neurological disorders

In this study levels of neuron-specific enolase (NSE), S-100 protein (S-100) and myelin basic protein (MBP) in cerebrospinal fluid (CSF) of children and adults with distinct neurological disorders were examined. A previous study from our department demonstrated age related reference values for these brain-specific proteins in CSF. The median concentration level of the 3 proteins in 17 different neurological disease groups versus the reference group was compared. Significantly higher MBP values were observed in patients with multiple sclerosis (MS), cerebrovascular accident (CVA), metabolic disorder and infection. Furthermore, significantly higher values were demonstrated for S-100 in CVA and for NSE in metabolic diseases. In CVA, the NSE and S-100 values were significantly related with MBP values, whereas in MS the NSE and S-100 were not related with MBP values.

Elevated cerebrospinal fluid levels of manganese superoxide dismutase in bacterial meningitis

We examined the mechanism of increase of manganese superoxide dismutase (Mn SOD) in the cerebrospinal fluid (CSF) in bacterial meningitis (BM). The elevated levels of Mn SOD in the CSF in BM, measured with an enzyme immunoassay method, were more prominent than those in aseptic meningitis (AM) and encephalitis (EN). In AM and EN Mn SOD levels well correlated with levels of neuron-specific enolase and S-100b protein, which are markers of damages to nervous tissues, but did not with any of them in BM. CSF concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha) were higher in BM than in AM and EN. From the serial measurements in BM, the peak values of these cytokines chronologically preceded or corresponded to those of Mn SOD. Immunohistochemically, a large number of the glial cells were stained for Mn SOD in the cerebral cortex from a patient with BM. By contrast, in the normal cerebral cortex, the glial cells were negative for Mn SOD staining. These results suggest that the marked increase of Mn SOD in the CSF in BM may be related to the increase of such cytokines as TNF-alpha and IL-1 alpha and that these cytokines may play a role in the induction of Mn SOD in nervous tissues.

Cerebrospinal fluid concentration of neuron-specific enolase in diagnosis of Creutzfeldt-Jakob disease

Neuron-specific enolase (NSE) is among the biochemical markers in cerebrospinal fluid reported to be useful in the differential diagnosis of Creutzfeldt-Jakob disease from other dementing illnesses. In a group of 58 patients with definite and probable Creutzfeldt-Jakob disease, NSE concentrations (median 94.0, interquartile range 256 ng/mL) were significantly higher (p < 0.001) than in 26 control patients (9.5, 15.5 ng/mL). At a cut-off of 35 ng/mL an optimum sensitivity of 80% with a specificity of 92% for the diagnosis of Creutzfeldt-Jakob disease by NSE in cerebrospinal fluid was obtained.

Cerebrospinal fluid levels of S-100b protein and neuron-specific enolase in chronic inflammatory demyelinating polyneuropathy

We measured the cerebrospinal fluid (CSF) concentrations of S-100b protein (S-100b) and neuron-specific enolase (NSE) using enzyme immunoassay methods in 15 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), other three patients with chronic neuropathy with demyelination, eight patients with various axonal neuropathies (AN), and 46 controls, to investigate the clinical usefulness of the determination of these two specific proteins in these neuropathies. S-100b levels were elevated (> the mean +/- 2 SD levels of controls) in the majority of patients with clinically progressing CIDP (9/11), but not in the patients with AN (0/8). In parallel with the clinical improvement, S-100b levels were normalized in patients with CIDP (10/10), though total protein levels in the CSF still remained high in some of these patients (5/10). Elevation of NSE levels were seldom seen in clinically worsening patients with CIDP (1/11) or AN (1/8). Thus our results indicated that the level of S-100b in the CSF may be useful to assess the activity of actual disease process in CIDP.

Cerebrospinal fluid neuron-specific enolase in Alzheimer's disease and vascular dementia

Levels of neuron-specific enolase (NSE), a glycolytic enzyme localized in neurons, were measured in serum and cerebrospinal fluid (CSF) of patients with early-onset (e-AD) and late-onset (l-AD) Alzheimer's disease, vascular dementia (VD) and controls. Mean CSF NSE levels in patients with Alzheimer's disease did not significantly differ from those in controls, although in the AD group a correlation was found between NSE levels and severity of cognitive deficits. In VD patients, CSF NSE was lower than in controls or in AD patients. These findings are of physiopathological interest but suggest that CSF NSE is not a useful biological marker in dementia disorders.

Serum neurone-specific enolase concentrations in patients with neurological disorders

A radioimmunoassay (RIA) has been developed for neurone-specific enolase (NSE) and used to measure serum levels in patients with a range of neurological disorders. Serum NSE levels were within the normal range in 21 patients with multiple sclerosis and 4 patients with Guillain-Barre syndrome. Normal serum NSE levels were also recorded in patients with motor neurone disease, anterior spinal thrombosis, multi-infarct disease, benign intracranial hypertension and peripheral neuropathy. However, two patients in coma, one as a result of encephalitis, the other due to subarachnoid haemorrhage (SAH) had elevated serum NSE. In the former, serum NSE levels appeared to predict a deterioration in clinical state, levels later returning to normal before an improvement in clinical condition. In the patient with SAH, levels were elevated on admission and remained elevated until death. Serum NSE levels may be of use in predicting outcome in patients with acute neurological disease.

Neuron specific enolase in cerebrospinal fluid: a biochemical marker for neuronal degeneration in dementia disorders?

Alzheimer's disease (AD) is the most common disease causing dementia. Today the clinical diagnosis of AD is made by way of exclusion, and no biochemical markers are available to assist the clinical diagnosis. We examined the potential of neuron-specific enolase (NSE) in cerebrospinal fluid (CSF) as a diagnostic marker for AD. NSE was determined with a monoclonal antibody two-site immunoradiometric assay (IRMA) in serum (S) and cerebrospinal fluid (CSF) samples from 45 patients with "probable Alzheimer's disease (AD)", 19 patients with vascular dementia (VAD) and 33 age-matched healthy individuals. There was no significant correlation between S-NSE and CSF-NSE, or between CSF/S albumin ratio and CSF-NSE, findings suggesting that the major portion of CSF-NSE is intrathecally produced and that analysis of CSF-NSE alone (without accompanying analysis of serum) is sufficient. CSF-NSE was significantly higher in the AD group (4.7 +/- 2.7 ng/mL; p < 0.0001) and in VAD group (4.5 +/- 2.5 ng/mL; p < 0.001) as compared with the control group (2.2 +/- 1.0 ng/mL), while it did not differ significantly between the AD and the VAD group. These findings suggest that CSF-NSE have a potential as a non-disease specific marker for the neuronal degeneration in dementia disorders.

Cerebrospinal fluid levels of superoxide dismutases in neurological diseases detected by sensitive enzyme immunoassays

We measured cerebrospinal fluid (CSF) levels of Cu/Zn superoxide dismutase (Cu/Zn SOD) and Mn superoxide dismutase (Mn SOD) using enzyme immunoassays in 196 neurological patients and 44 controls. The mean Cu/Zn SOD level was 55.8 +/- 27.6 (SD) ng/ml and the Mn SOD, 8.0 +/- 2.5 ng/ml in the controls. Cu/Zn SOD or Mn SOD levels showed neither age-nor sex-related differences in the controls. Both SODs were markedly elevated in cerebrovascular diseases, bacterial meningitis and encephalitis. Mn SOD alone was significantly elevated in neurodegenerative diseases. We compared SODs with CSF levels of neuron-specific enolase (NSE) and S-100b protein (S-100b) in cerebral infarction and bacterial meningitis. Both SODs were correlated with NSE and S-100b in patients with cerebral infarction, but not in those with bacterial meningitis. This means that elevations of SODs in CSF may not only be due to leakage from damaged nervous tissues, but also to the induction of SOD in lesions. We conclude that the mean SOD levels were elevated in various neurological diseases, and their varied magnitudes may be associated with the underlying diseases.

The brain protein S-100ab induces apoptosis in PC12 cells

Incubation of PC12 cells with S-100 protein induces a rapid (0.5-1.0 min) rise of intracellular Ca2+ which lasts for the whole period of incubation. This effect is abolished in a Ca(2+)-free medium or in the presence of 1.0 microM Ni2+, an inhibitor of calcium channels. The rise in intracellular Ca2+ is followed by a progressive increase of cells undergoing degeneration and death. This event is accompanied by the appearance of apoptotic bodies and DNA fragmentation typical of the process known as apoptosis. S-100-induced cell death is prevented by 1 microM Ni2+ or by 0.1 nM cycloheximide, suggesting the involvement of new protein synthesis. It is postulated that the binding of S-100ab to specific sites present in PC12 cells is followed by the formation of Ca2+ channels and/or the stimulation of pre-existing ones with consequent increase of Ca2+ influx and activation of a process of cell death.

Neural tissue-related proteins (NSE, G0 alpha, 28-kDa calbindin-D, S100b and CK-BB) in serum and cerebrospinal fluid after cardiac arrest

To estimate brain damage after cardiac arrest, the concentrations of neuron specific enolase (NSE), GTP-binding protein (G0 alpha), 28 kDa calbindin-D, S100b protein, and creatine kinase BB (CK-BB) in serum and cerebrospinal fluid (CSF) were determined by enzyme immunoassays. Ten mongrel dogs were subjected to 30 min of circulatory arrest at normal body temperature and serial CSF and blood samples were taken during the first 18 h after reperfusion. The NSE concentration in CSF increased significantly after reperfusion, reaching a 15-fold increase (243 +/- 107 ng/ml, p < 0.01) 18 h later, however, it did not increased significantly in serum (8.1 +/- 3.3 ng/ml vs. 23.5 +/- 7.0 ng/ml). G0 alpha concentration in CSF increased sharply between the 2nd and 4th h after reperfusion and peaked 18 h after reperfusion (428 +/- 195 pg/ml, p < 0.01), however, it did not increase significantly in serum. Calbindin-D concentration in CSF increased between the 1st and 6th h after reperfusion, and reached a plateau thereafter (621 +/- 235 ng/ml, a 23-fold increase, p < 0.05) and also increased significantly in serum (p < 0.05). The S100b concentration in CSF also increased dramatically after the 4th h of reperfusion and reached a plateau at the 8th h after reperfusion (16.0 +/- 9.3 ng/ml, a 50-fold increase, p < 0.01), however, it in serum was below the detection threshold. The CK-BB concentration in CSF peaked 4 h after reperfusion (113 +/- 69 ng/ml, a 19-fold increase, p < 0.01) and it in serum increased 4-fold (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

A sensitive ELISA for glial fibrillary acidic protein: application in CSF of adults

The present study concerns an ELISA for glial fibrillary acidic protein (GFAP) in cerebrospinal fluid (CSF). The application of the method in CSF of children has previously been described in this journal. We have now adapted the technique to allow determination of the much higher GFAP concentrations found in normal and pathological CSF of adults. The assay range was extended to 16,000 pg/ml. CSF levels as high as 170,000 pg/ml could be assayed since dilution experiments indicated immunological identity between purified GFAP and GFAP in CSF. In normal controls the concentrations correlated significantly with age (P < 0.001, Spearman rank correlation test). The concentrations were less than 200 pg/ml before 20 years of age and increased to between 500 and 1300 pg/ml at approximately 75 years of age. This increase of CSF GFAP probably reflects formation of astroglial filaments in the CNS and it must be taken into consideration when determining the pathological CSF GFAP level. The method was validated using CSF samples from patients with either astrogliosis or acute tissue destruction in the CNS. Although augmented levels were observed in both groups it is quite clear that patients with acute tissue destruction may display very high CSF GFAP concentrations, whereas levels in patients with astrogliosis were only modestly increased if at all.

The changes in the permeability of the blood-brain barrier when under neurosurgical intervention

The aim of this research was to determine the influence of anesthesia, drugs, and neurosurgical trauma on the permeability of the blood-brain barrier (BBB) for macromolecules. Protein markers of oligodendrocytes and astroglia were used. The research methods were unique. Two groups of patients were formed: with neurosurgical brain trauma and without it. Everyone in both groups was subjected to anesthesia. The results were unexpected and did not depend on surgery: 1. Neurosurgical brain trauma did not change the permeability of BBB. 2. Anesthesia resulted in increasing permeability of BBB with peak upon 24-48 h. 3. High blood levels of neurospecific proteins proved protein synthesis in glial cells. 4. Massive transferring of brain antigens into blood did not stimulate antibody synthesis during a period of 21 d. According to the high blood levels of neural proteins, the antigen-antibody reaction took place in blood and autoimmune complexes were eliminated before penetration into the brain. A new mechanism of brain autoimmune safety is discussed.

Neuron-specific enolase increases in cerebral and systemic circulation following focal ischemia

Neuron-specific enolase (NSE) is an isoform of the glycolytic enzyme, enolase, and is found in neurons and neuroendocrine cells. We evaluated cerebral immunohistologic and plasma changes in NSE in rats from 2 h to 15 days following permanent or transient middle cerebral artery occlusion (MCAO). At 1-2 days post-MCAO, loss of NSE immunofluorescence from within neurons to the extracellular space was observed in the infarcted areas of all MCAO animals. NSE also was identified intravascularly throughout the brain following MCAO. NSE in plasma was determined by a specific radioimmunoassay. Plasma NSE following permanent or transient MCAO was increased significantly from that observed in controls (2.8 +/- 0.3 ng/ml) beginning at 2 h and persisting for 2.5 days post-MCAO (maximum levels of 8.8 +/- 0.9 to 9.6 +/- 0.5 ng/ml after 6-12 h; P < 0.05, n = 4-9). Quantified contralateral forelimb and hindlimb neurological deficits in these animals were significant and persisted for at least 15 days following MCAO but were not observed following sham surgery. These data suggest that MCAO-induced cortical infarction and neurological dysfunction is associated with neuronal depletion and vascular redistribution of brain NSE resulting in a measurable increase in plasma NSE. Such diffusion of NSE into the cerebral vasculature and systemic circulation from ischemic tissue can be expected to serve as a marker for the incidence of cerebral damage in acute and chronic ischemic brain infarcts.

Cerebrospinal fluid 28-kDa calbindin-D as a possible marker for Purkinje cell damage

To examine the clinical value of 28-kDa calbindin-D (CaBP) in cerebrospinal fluid (CSF) as a marker for the damage to Purkinje cells, we measured CSF CaBP levels using an enzyme immunoassay method in 107 patients with cerebellar and other neurological diseases, and 26 controls. The mean CaBP level was markedly elevated in patients with cerebellar diseases, and the elevation of CaBP level was more frequent in the diseases involving Purkinje cells, such as multiple system atrophy (MSA) and subacute cerebellar degeneration in association with lung cancer. Further, in MSA patients, the CaBP levels decreased with duration of illness. The mean levels of CaBP were also elevated in some of the other diseases. We conclude that the elevations of CaBP levels are not specific for cerebellar diseases, but CSF CaBP may be a useful marker for examining the Purkinje cell involvement in cerebellar diseases.

Glial fibrillary acidic protein in the cerebrospinal fluid of children with autism and other neuropsychiatric disorders

The cerebrospinal fluid (CSF) of 47 children and adolescents with autism was analyzed for the contents of two astroglial proteins, the glial fibrillary acidic protein (GFA) and S 100. The results were contrasted with those obtained in similarly aged cases with other neuropsychiatric disorders (n = 25) and in normal children (n = 10). S-100 did not discriminate the groups from each other. However, GFA in autism and autistic-like conditions was at a level almost three times that in the normal group. The results could implicate gliosis and unspecific brain damage in autism. An alternative model would be increased synapse turnover regardless of underlying cause.

The S-100 protein causes an increase of intracellular calcium and death of PC12 cells

The S-100 protein-PC12 cell interaction has been studied as a model system of the possible physiological role played by S-100 protein in the nervous system. The data reported demonstrate that S-100 exerts a cytotoxic action which eventually leads to PC12 cell death, regardless of the cell cycle phase. The effect is specific for the S-100 isoforms, which are made up of two identical subunits and is abolished by a monoclonal antibody directed against the same isoforms. Other isoforms and/or calcium-binding proteins, such as troponin or calmodulin, do not induce the same effects. The action of S-100 on cell viability is not detectable in other cell lines of different embryological origin, such as 3T3, L1210, GH3. S-100 causes a rapid and considerable increase (two- to three-fold) of intracellular Ca2+ concentration in PC12 cells accompanied by cytostatic and cytotoxic action. It is postulated that this action also occurs in vivo, as part of the physiological action of this protein.

A sensitive ELISA for glial fibrillary acidic protein: application in CSF of children

In the present study we describe a sensitive ELISA for determination of glial fibrillary acidic protein (GFAP). To validate the method combined determinations of GFAP and S-100 protein were performed in cerebrospinal fluid (CSF) of normal children and children with autism. The GFAP ELISA is of sandwich type and uses the biotin-avidin system. Sensitivity was 16 pg/ml. Between-day precision was 0.079 (coeff. of variance). S-100 protein concentrations were measured using a commercially available ELISA kit. Normal CSF from children and young adults were analysed. The CSF levels of GFAP in normal children were low (16-163 pg/ml). Both GFAP and S-100 protein concentrations correlated with age (P < 0.01 and P < 0.05, respectively), but the GFAP increment was more pronounced, probably reflecting the age-dependent expansion of the fibrillary astrocytes in the central nervous system (CNS). GFAP levels in children with infantile autism were higher than those in normal children of the same age range. S-100 protein concentrations were similar in both groups. High levels of GFAP in combination with normal S-100 protein concentrations in CSF indicates reactive astrogliosis in the CNS. In conclusion, the sensitive ELISA described makes it possible to measure low levels of GFAP present in the CSF of children. Combined assays of GFAP and S-100 protein can be used to discriminate between acute and chronic brain disorders in children.

Effect of chronic pre- and post-natal low-dose ethanol exposure on brain enolase isoenzyme activities

Sprague-Dawley dams were treated with 3 v/v % ethanol in liquid diet from the 8th day gestation through 3 weeks nursing period. Offsprings, ages 1, 2 and 3 weeks, and their dams were studied. Brain weights and their total proteins were not affected by this ethanol treatment. Total enolase activity/mg protein and its isoenzymes, i.e. non-neuron-specific, hybrid and neuron-specific, (mumol/min/mg protein) in 100,000 g supernate, were significantly lower in the treated. Additionally, enolase isoenzyme transformation was delayed.

CSF neuron-specific enolase as a quantitative marker of neuronal damage in a rat stroke model

A technique for chronic cisternal cerebrospinal fluid (CSF) sampling in conscious rats was used to obtain multiple 50 microliters samples before and up to 7 days after middle cerebral artery occlusion. Neuron-specific enolase (NSE) concentrations were measured by radioimmunoassay using a readily available kit. The volume of infarction was measured by integrating the area of damage on 9 evenly spaced histological sections of the forebrain. This correlated well (r = 0.97, P less than 0.001) with the concentration of CSF neuron-specific enolase integrated over the first 5 days post occlusion, in animals with pure cortical and mixed cortical and striatal lesions. The correlation was maintained in animals given the NMDA antagonist MK-801. There was also a good correlation between the CSF NSE concentration 3 days post-MCAO and the volume of infarction (r = 0.92, P less than 0.01). It is therefore possible that CSF neuron-specific enolase may be useful as a quantitative marker of ischaemic damage in humans and provide a useful adjunct in the assessment of neuroprotective drugs in stroke.

Serum neurone specific enolase (NSE) levels as an indicator of neuronal damage in patients with cerebral infarction

A radioimmunoassay has been developed and used to measure serum neurone specific enolase (NSE) concentrations in 24 patients, following cerebral infarction. A significant correlation between cerebral infarct volume and maximum serum NSE concentration was observed (P = 0.047). Serum NSE was also assayed at times 24, 48, 72 and 96 h post ictus. At 72 h a significant correlation existed between serum NSE levels and infarct volume (P = 0.012), and levels appeared to be approaching statistical significance at 48 h (P = 0.067). No correlation existed at 24 and 96 h. In addition serum concentrations of NSE were compared to clinical outcome as determined by the Glasgow Outcome Score. Using the Mann-Whitney U test, there was no significant difference in maximum NSE level between patients graded 1-3 on the Glasgow Outcome Score and those graded 4 and 5. However, further studies are required on a larger population to more completely assess this. NSE may prove to be a useful marker of neuronal damage in the study of stroke, with particular application in the assessment of treatment.

Determination of S-100 and glial fibrillary acidic protein concentrations in cerebrospinal fluid after brain infarction

BACKGROUND AND PURPOSE

We initiated the present study to evaluate the clinical value of consecutive concentration determinations of S-100 and glial fibrillary acidic proteins in cerebrospinal fluid from patients with brain infarction.

METHODS

We took sequential samples of cerebrospinal fluid from 28 patients within 48 hours, at 7 days, and at 18-21 days after the ictus. We measured astroglial protein concentrations using an enzyme-linked immunosorbent assay and also determined size of the infarction (computed tomography), clinical state of the patient (simplified activities of daily living test), blood-brain barrier dysfunction (cerebrospinal fluid/serum albumin ratio), and a myelin marker (myelin basic protein).

RESULTS

We found a transient increase of both proteins in the cerebrospinal fluid during the first week after the ischemic stroke (p less than 0.05). This increment was significantly correlated with the size of the infarction and the clinical state of the patients.

CONCLUSIONS

Transient release of astroglial proteins into the cerebrospinal fluid possibly reflects initial focal ischemic damage and, in the later phase, ongoing destruction of astroglial cells in the penumbra zone. We suggest that determinations of cerebrospinal fluid astroglial protein concentrations can be used to estimate ischemic brain damage, which should be of particular value in clinical trials of pharmacological agents, such as calcium antagonists, on stroke patients.

Changes of neuron-specific enolase concentration in plasma after cardiac arrest and resuscitation

The concentration of neuron-specific enolase (NSE) was measured in plasma of 18 patients after cardiac arrest and resuscitation (14 nonsurvivors and 4 survivors). In all patients, the NSE concentration was significantly higher in comparison to reference values. The highest concentration was measured in nonsurvivors. Time-course investigation in the first 24 h after cardiac arrest was performed in five patients. Two nonsurvivors and one survivor of the five patients showed a significant rise, and a NSE peak concentration of 42.7 micrograms/L, 13.6 micrograms/L, and 10.5 micrograms/L, respectively, was found 10-19 h after cardiac arrest.

Cerebrospinal fluid markers in neurological disorders

Cerebrospinal fluid (CSF) markers are a useful tool for determining disease progression or activity in some neurological disorders which need parameters both for evaluating treatments and investigating pathobiological evolution in research-oriented follow-up. A number of CSF proteins are reviewed with data on biological properties, analytical methods, clinical usefulness of: myelin basic protein, S-100 protein, glial fibrillary acidic protein, neural-cell adhesion molecule, neuron-specific enolase and others.

Neuron specific enolase (NSE) and thymidine kinase (TK) as markers in biological fluids of brain tumor patients

We studied the activity of two enzymes NSE and TK in the biological fluids of 104 patients with nervous system diseases, who fell into 4 groups. 20 subjects out of 35 in the tumor group had glial tumors. We fixed a cut-off value of NSE and TK activity at the 95th percentile of the control group, both in serum and in CSF. The aim of our investigation was to assess the reliability of TK and NSE assays in separating brain tumors from other neurological diseases. In our patients, most of the TK activity above the cut-off value was found in the tumor group. Serum TK seems to be a useful marker for following up cerebral tumors after surgery, but NSE is less useful for this purpose.

Detection of neuron specific enolase concentrations in cerebrospinal fluid from patients with neurological disorders by means of a sensitive enzyme immunoassay

An enzyme linked immunosorbent assay (ELISA) for the detection of neuron specific enolase (NSE) in cerebrospinal fluid (CSF) was developed. The sensitivity of the ELISA was less than 1 microgram/ml. This sensitivity is comparable with radioimmunoassays which have the disadvantage that radiolabelled products are used. The developed assay was used to measure cerebrospinal fluid neuron specific enolase (CSF-NSE) levels in 1178 patients with neurological disorders to establish its potential usefulness and clinical application. CSF-NSE levels in this group of patients were independent of sex and no correlation with age was found. CSF-NSE was significantly increased in Creutzfeldt-Jacob disease, meningeal hemorrhage, thrombosis, Guillain-Barré syndrome and in schizophrenia.

Analysis of immune complexes of cerebrospinal fluid by two-dimensional gel electrophoresis

From the cerebrospinal fluid of 32 patients with different neurological diseases immune complexes were isolated using protein A-Sepharose. The isolated heavy and light chains and their constituents were analyzed by two-dimensional gel electrophoresis. In addition to immunoglobulins, some proteins such as albumin, apolipoprotein A-I and a number of unknown proteins were detected in all preparations. A complex consisting of three proteins with molecular masses between 52-55 kDa reacted slightly with polyclonal antibodies to glial fibrillary acidic protein. Whether the linkage between these antigens and the Ig is due to the Fab region or the Fc region remains unknown in our study. In some immune complexes of neurological diseases such as amyotrophic lateral sclerosis, astrocytoma and multiple sclerosis, differences are easily recognizable in the gel pattern.

Elevated levels of the alpha subunit of GTP-binding protein Go in cerebrospinal fluid of patients with neurological disorders

By employing a highly sensitive immunoassay method, concentration of the alpha subunit of GTP-binding protein, Go (Go alpha), recently shown to be localized mainly in nervous tissues and neuroendocrine cells, was determined in cerebrospinal fluids (CSF) of 192 patients with various neurological disorders and 50 control subjects. The results were compared with CSF levels of neuron-specific enolase (NSE) and S-100b protein (S-100b) in the same samples. Normal levels of Go alpha were 51.9 +/- 21.7 pg/ml. The levels of Go alpha, as well as NSE and S-100b, in CSF were enhanced in some patients with acute conditions, e.g., meningitis (48%), encephalitis (100%), and cerebral infarct (56%). In these disorders, cases with enhanced Go alpha levels were more frequent than those with enhanced NSE or S-100b. Three patients with encephalitis whose Go alpha levels were more than 1000 pg/ml all died; the remaining two patients with encephalitis and slightly elevated Go alpha levels had a good prognosis. Concentration of Go alpha in CSF correlated well with that of NSE but poorly with that of S-100b. However, cervical spondylosis and demyelinating diseases, CSF levels of Go alpha were generally lower than those of NSE or S-100b. These results suggest that Go alpha in CSF is a useful marker for monitoring patients with acute neuronal damage. Since these three proteins are distributed differently in the central nervous system, simultaneous determination of Go alpha, NSE, and S-100b levels in CSF might provide valuable information about the pathophysiology of neurological disorders.

The S-100 protein in cerebrospinal fluid: a simple ELISA method

A simple ELISA method is described for determinations of S-100 protein concentrations in CSF. The assay has a useful range of 200-3200 pmol/l. The precision of the ELISA was estimated using a pool of CSF. The coefficient of variation was 0.18 within assay, 0.17 between assay and 0.17 between day. The S-100 protein is stable in the CSF as no measurable differences in S-100 concentrations were observed in samples stored at room temperature for 2 days. No correlation between age and S-100 concentration was found when determinations were performed in CSF from neurologically healthy males. Furthermore, no changes of S-100 was observed in a lumbocisternal CSF gradient from patients with normal pressure hydrocephalus. Thus, the described ELISA represents an easy to handle and reliable method, well suited for routine determinations of S-100 protein concentration in the CSF.

Clinical relevance of increased neuron-specific enolase concentration in cerebrospinal fluid

Neuron-specific enolase (NSE) concentrations in cerebrospinal fluid (CSF) and serum have been studied by an EIA-method using monoclonal antibodies against human NSE. In a control group (n = 24) the mean NSE value (+/- SD) in CSF was 10.8 (+/- 4.5) ng/ml. Increased NSE values in CSF (greater than or equal to 20 ng/ml, ie greater than or equal to means + 2s) have been detected in 33/172 patients with the following neurological diseases: CNS tumors (6/30), infarctions (6/36), cerebral ischemias (5/25), inflammatory diseases (7/33), epilepsias (3/10) and miscellaneous neurological diseases (6/38). The NSE assay in CSF was not specific for a single neurological disease. In 9% of all patients with an organic neurological disease the increased NSE concentration was the only abnormal result in the CNS out of variables routinely determined in CSF. The discrimination between an organic and psychogenic origin of epilepsy may be possible by an NSE analysis in CSF. The NSE assay in CSF can be recommended as an unspecific screening parameter for pathological organic CNS processes.