CSF tau protein and beta-amyloid (1-42) in Alzheimer's disease diagnosis: discrimination from normal ageing and other dementias in the Greek population

Cerebrospinal fluid (CSF) levels of tau protein and amyloid beta(1-42) peptide (Abeta42) have been suggested as possible diagnostic markers of Alzheimer's disease (AD). In order to evaluate their diagnostic potential in clinical practice, we measured tau and Abeta42 levels in the CSF of 49 AD patients, 15 patients with non-AD neurodegenerative dementias (NAND), six patients with vascular dementia (VD) and 49 elderly controls. All the subjects were of Greek origin. A marked increase in tau, a decrease in Abeta42 and a marked increase in the tau/Abeta42 ratio was noted in AD. Abeta42 alone had a specificity of 80% and a sensitivity of 82% in differentiating AD from normal ageing, whilst the corresponding values for differentiating AD from NAND or VD were 80 and 71, or 67 and 82%, respectively. Tau was better in differentiating AD, from normal ageing (specificity 96%, sensitivity 88%), NAND (specificity 93%, sensitivity 71%) and VD (specificity 83%, sensitivity 94%). The tau/Abeta42 ratio achieved values comparable or even better than tau for differentiating AD from normal ageing (specificity 86%, sensitivity 96%) and VD (specificity 83%, sensitivity 90%) and definitely better than any of the candidate markers alone, for differentiating AD from NAND (specificity 100%, sensitivity 71%). Thus, the combined use of CSF tau and Abeta42 in the form of the tau/Abeta42 ratio is a simple, safe and useful adjuvant to clinical criteria for dementia diagnosis.

Thyroid gland neurofibroma in a NF1 patient

Neurofibromas are a hallmark of neurofibromatosis type 1 (NF1). They are usually benign and rarely present in the thyroid gland region. There is a suspected association between NF1 and intramedullary thyroid carcinoma and there is a well-known association between NF1 and pheochromocytoma. Here, we present a 55-year-old man with typical symptoms of NF1, whose course was complicated by a neurofibroma of the thyroid gland. His clinical spectrum of symptoms included bilateral cataract established before the age of 35 years, quadriparesis and an intrathoracic mass. The patient died because of abdominal carcinomatosis of unknown origin. The rarity of thyroid gland neurofibroma is discussed here, emphasizing the importance of early detection of these and other NF1 complications, also including the risk of malignant transformation with lethal outcome.

Periodic alternating nystagmus associated with Arnold-Chiari malformation

The Arnold-Chiari malformation type I is a rare congenital condition characterized by herniation of the cerebellar tonsils into the upper cervical spinal tract. Various otoneurological manifestations occur in patients with the disease, which has usually been associated with a downbeat type of nystagmus. In this paper a case with this condition is reported presenting with periodic alternating nystagmus (PAN), which is a rare type of nystagmus observed in diseases of the central nervous system of different pathologies. The patient had a complete otoneurological examination and vestibular function testing. Diagnosis was established by using magnetic resonance imaging (MRI).

Area-selective stimulus-provoked seizures in post-anoxic coma

We describe the case of a 70-year-old patient in whom hemiconvulsive seizures occurred during metabolic derangement, multiple stroke and post-anoxic coma following cardiac arrest. We employed the methods of clinical and EEG evaluation and CT brain scan. We found that hemiconvulsive seizures were provoked following a light tactile stimulus in the left-trigeminal area and occasionally a strong tapping in the right-trigeminal area. We conclude that this type of stimulus-provoked seizure is extremely rare and could be explained by diffuse and severe brain damage.

The usefulness of sleep and sleep deprivation as activating methods in electroencephalographic recording: contribution to a long-standing discussion

Sedated sleep and sleep deprivation are commonly used methods to increase the diagnostic yield of the electroencephalogram (EEG), especially in the evaluation of people with epilepsy, but the rate of activation achieved by them is controversial, as is the issue of whether it is sleep itself, or sleep deprivation which is responsible for their alleged efficacy. We retrospectively studied the EEGs of epileptic patients, examined in our laboratory, who, after having undergone an inconclusive initial routine recording, had then been examined with a second recording. This was after either: (1) sleep deprivation with evidence of drowsiness in the recordings, (2) sleep deprivation without drowsiness (indicative of the effect which sleep deprivation per se has in eliciting abnormal patterns), or (3) drug-induced sedation. The activation rates found were (1) 22.5%, (2) 24% (22.6% for sleep deprivation collectively, regardless of the presence or not of subsequent drowsiness) and (3) 27% respectively. Only the sleep deprivation rate was statistically different from the 9.6% increased rate of abnormal patterns elicited by the simple repeating of a second routine recording, while the rate of drug-induced sleep was not. Although, sleep deprivation appeared to be more effective as an activating method of EEG compared with sedated sleep, no conclusions could be drawn about which stage of sleep, wakefulness or drowsiness, is primarily responsible for the method's efficacy.

Convulsive status epilepticus following abrupt high-dose benzodiazepine discontinuation

The misuse of benzodiazepines (BNZ)s may result in serious side effects. Three cases of convulsive status epilepticus (CSE) following abrupt discontinuation of long-term use of 25 mg of lorazepam in one patient and more than 20 mg of flunitrazepam in two patients are presented; they were non-epileptics and free of other high-risk factors for seizures. A favorable outcome for all three cases was noted. They remain free of seizures without antiepileptic treatment. Nevertheless, because of the extensive use of benzodiazepines, such rare high-risk side effects must be emphasized.

Cerebrospinal fluid levels of biotin in various neurological disorders

OBJECTIVES

To analyse biotin concentrations in human cerebrospinal fluid (CSF) and serum from controls without evidence of nutritional or neurological disorders and patients with common neurological disorders.

PATIENTS AND METHODS

Cerebrospinal fluid was obtained from patients by lumbar puncture, serum was prepared from freshly drawn whole blood and biotinidase in samples was inhibited before being analysed for biotin by radioligand assay.

RESULTS

Assay characteristics were within an acceptable range (intra-and interassay coefficient of variations were 8.8 and 12.0 respectively, recovery: 91-114% and sensitive, lowest standard concentration 15 ng/l). Significantly lower values for biotin were found in patients with multiple sclerosis (both CSF and serum) in comparison to the controls. Significantly reduced values for cerebrospinal fluid biotin were found in epileptics compared to controls, whereas, in serum the difference was approaching significance. No significant differences were observed in other groups of patients.

CONCLUSION

There is a significant reduction in cerebrospinal fluid biotin in epileptics and patients with multiple sclerosis compared to controls. In epileptics this may be related to competition between biotin and anticonvulsants bearing carbamide ring for absorption. Reduction of biotin levels in patients with multiple sclerosis could be attributed to intestinal malabsorption caused by the underlying disease or a biotin-binding immunoglobulin which may be involved in multiple sclerosis pathogenesis.

A case of fever following antiepileptic treatment

A 23-year-old female patient treated with 900 mg oxcarbazepine for complex partial seizures is presented. Good seizure control and slight fever were noted a few weeks after drug administration. Reduction of oxcarbazepine and replacement with valproate resulted in a transient normothermia. Because of fever reappearance, vigabatrin was added and valproate was gradually reduced. Seizures reappeared, but the body temperature fell below 37 degrees C. Substitution of valproate for lamotrigine resulted in seizure control but abnormal body temperature (37- 37.6 degrees C) was noted again. Repeated hospital admission for clinical and laboratory investigation before any change of treatment revealed no other abnormal findings. The patient's abnormal temperature possibly reflects a derangement of high-level temperature control.

Ascorbate in healthy subjects, amyotrophic lateral sclerosis and Alzheimer's disease

The aim of the present study was to report the levels of ascorbic acid in amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD) and the effectiveness of ascorbic acid homeostasis in the central nervous system. Plasma and CSF ascorbic acid levels were measured by high performance liquid chromatography in 19 ALS patients, 17 AD patients and 15 controls. No statistically significant difference was found between patients and controls. However, wide fluctuations of plasma concentrations were found to result in relatively stable CSF levels, by appropriate adjustments of CSF/plasma ratio. It appears that in normal subjects and in the disease under study, this ratio reflects the activity of the choroid plexus ascorbate transporter.

Essential trace element alterations in amyotrophic lateral sclerosis

Although trace elements have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) for a long time, new evidence has connected familial ALS with the metalloenzyme copper-zinc superoxide dismutase, thus reinforcing the study of their metabolism. This work presents the results of serum and cerebrospinal fluid levels of copper, zinc, manganese and magnesium, by atomic absorption spectrophotometry. Statistically significant decreased cerebrospinal fluid and serum copper levels were found in patients compared to the control group (20.25 +/- 7.09 vs. 30.86 +/- 16.02 SD micrograms/l and 913.21 +/- 165.55 vs. 1020.17 +/- 197.76 SD micrograms/l) while serum manganese levels were found to be increased in patients (3.59 +/- 0.89 SD micrograms/l) compared to controls (3.03 +/- 1.23 SD micrograms/l). Zinc and magnesium levels were unchanged. Our findings indicate an essential trace element imbalance in the disease.

Raeder's syndrome. Report of two cases

Raeder's syndrome constitutes facial pain and ipsilateral stenosis of the palpebral fissure, miosis and enophthalmos. It is divided into two groups. Group I includes cases with parasellar cranial nerve involvement and group II without parasellar cranial nerve involvement. It is often difficult to distinguish group II of Raeder's syndrome from Horner's syndrome. The latter is painless and is accompanied by anidrosis of the ipsilateral half of the face. In fact Raeder's syndrome may be caused by any lesion affecting the post-ganglionic oculosympathetic fibers distal to the bifurcation of the common carotid artery. Serious lesions of the internal carotid artery (ICA) may be responsible for this syndrome. This paper deals with two cases of group II of Raeder's syndrome. In the first case, a 60-year-old man, the angiogram revealed an aneurysm of the extracranial part of the ICA just below its entrance into the calvarium. In the second case, a 42-year-old man, a dissective aneurysm of the ICA was found. Surgery was not attempted in either of our patients for different reasons. Their symptoms ameliorated quickly with medical treatment.

Gadopentetate dimeglumine-enhanced MR in the diagnosis of the Tolosa-Hunt syndrome

A 54-year-old man first was admitted with a right oculomotor nerve palsy that ameliorated spontaneously. Two months later, he was readmitted with right proptosis, ophthalmoplegia, and optic nerve involvement. MR showed an enlarged right cavernous sinus. There was dramatic improvement after high doses of steroids. MR findings 10 months later were normal. Thus, the diagnosis of the Tolosa-Hunt syndrome was established.

Exclusion mapping of the benign hereditary chorea gene from the Huntington's disease locus: report of a family

A Greek family is presented in which seven members suffered from benign hereditary chorea (a rare autosomal dominant non-progressive chorea without dementia). All patients and three informative healthy relatives were submitted to DNA analysis using probes from loci linked to Huntington's disease. The results confirm one previous suggestion that these two disorders are not allelic and that they should be considered as two distinct genetic entities.

Determination of cerebrospinal fluid and serum lead levels in patients with amyotrophic lateral sclerosis and other neurological diseases

In a total of 62 samples of cerebrospinal fluid (CSF) and an equal number of serum samples obtained from 16 patients suffering from amyotrophic lateral sclerosis, 22 patients suffering from miscellaneous neurological diseases, and 24 controls, lead was measured by atomic absorption spectrophotometry. No statistical difference in lead concentration was found between the above three groups.