Search

An accidental high dose of intraventricular mezlocillin was given during antibiotic treatment for pneumonia in a patient admitted because of severe traumatic brain injury and occlusive hydrocephalus. Because of serial epileptic seizures not responsive to antiepileptic drug treatment, CSF exchange was performed. The CSF was drained through a ventricular catheter, while mock CSF was infused into the lumbar subarachnoid space. The patient soon recovered to her clinical status previous to intraventricular mezlocillin application. Side effects of CSF exchange were not seen. Under continued antiepileptic medication no more seizures occurred. It is concluded that high doses of intraventricular mezlocillin have proconvulsive effects. In this patient CSF exchange was a suitable means of preventing putatively permanent impairment of brain function caused by serial epileptic seizures due to intraventricular mezlocillin application.

Phenylacetic acid, p-hydroxyphenylacetic acid, m-hydroxyphenylacetic acid, phenylalanine, indoleacetic acid, 5-hydroxyindoleacetic acid and tryptophan were measured in lumbar and cisternal cerebrospinal fluid (CSF) taken during pneumoencephalography. The data suggest that the concentration of the acid metabolites of the trace amines tryptamine, phenylethylamine, p-tyramine and m-tyramine in lumbar CSF are influenced by the system that transports these acids out of CSF. In cisternal CSF this mechanism does not operate and more information can be obtained on the metabolism of the parent amines in the CNS. Our data indicate that (1) m-tyramine is relatively unimportant quantitatively (2) the rate of metabolism of phenylethylamine in human brain is similar to that of 5-hydroxytryptamine (3) the most important variable controlling the synthesis of phenylethylamine is the activity of aromatic amino acid decarboxylase (4) p-tyramine is synthesised at about half the rate of phenylethylamine and is thus quantitatively important in metabolic terms.

Tryptophan, 5-hydroxyindoleacetic acid and indoleacetic acid were measured in cerebrospinal fluid, taken during pneumoencephalography, from a large series of patients, the majority of whom were epileptics, most of them receiving anticonvulsants. CSF indoleacetic acid reflects CNS tyrptamine metabolism in the same way that CSF 5-hydroxyindoleacetic acid reflects CNS 5-hydroxytryptamine metabolism. Our data suggest that (i) the brain tryptophan content is an important factor in the control of both 5-hydroxytryptamine and tryptamine synthesis (ii) brain 5-hydroxytryptamine metabolism exhibits a U-shaped relationship with age (iii) the mean brain tryptophan content and rate of 5-hydroxytryptamine metabolism are greater for women than men (iv) indoleamine metabolism is unaffected in untreated epileptics compared with non-epileptics, but anticonvulsant drugs decrease the rate of 5-hydrosytryptamine metabolism.

Vigabatrin (gamma-vinyl GABA) is a new anticonvulsive drug that irreversibly inhibits the activity of GABA transaminase. The effect of vigabatrin on neurotransmission-related amino acids in CSF of 28 epileptic patients was studied and the relationship between the amino acid pattern and clinical response during 7 months of administration of vigabatrin. Of this study population, 46% had more than 50% decrease in seizure frequency (responders). In 54% the seizures decreased less than 50% (nonresponders). In the whole study group, the levels of total GABA during vigabatrin treatment were 283%, free GABA 197%, homocarnosine 310% and glycine 128% that of the levels at baseline in the same patients. Glutamate, glutamine, aspartate, asparagine, and taurine concentrations did not change. The amino acid pattern in CSF during administration of vigabatrin did not differ significantly in responders and nonresponders. The study suggests that both GABAergic and glycinergic neurotransmission are affected by vigabatrin. The changes in CSF levels of neurotransmitter amino acids are, however, not necessarily related to the clinical response.

The possible role of different peptidergic systems in the postictal stage of human epilepsy was studied by measuring beta-endorphin, somatostatin, and prolactin levels by radioimmunoassay of cerebrospinal fluid (CSF) from nine epileptic patients. The first sample was taken within 2 hours after generalised tonic-clonic convulsion, and the second sample was obtained interictally after 1-4 days without any kind of clinically observable seizures. beta-endorphin was elevated postictally (p = 0.044) compared with interictal levels. SLI and PROL were similar in both samples. The present study suggests that in humans beta-endorphin is released into CSF during generalised seizures. This may indicate that neurons containing beta-endorphin are activated during a seizure.

Concentrations of individual free amino acids were determined in lumbar cerebrospinal fluid (CSF) from patients with various complaints including histologically verified Alzheimer's dementia. Glycine and glutamine in the CSF of Alzheimer's dementia samples were lower than that of control samples. Only the concentration of glutamic acid in Alzheimer's dementia patients correlated with psychological measures. The reduction in glycine concentration was not specific for Alzheimer's dementia.