Inhibitory and excitatory amino acids in cerebrospinal fluid of chronic epileptic patients

Abstract

We studied the levels of excitatory and inhibitory amino acids in the cerebrospinal fluid (CSF) of 28 epileptic patients (24 with partial type seizures, 4 with primary generalized seizures) and 12 controls. The levels of aspartate were 63% (p less than 0.01), glutamine 129% (p less than 0.001), and homocarnosine 127% (p less than 0.005) that of controls. The concentrations of glutamate, asparagine, total GABA, free GABA, taurine, and glycine did not differ between epileptic patients and controls. Patients with partial epilepsy had a pattern of amino acids in CSF similar to that in patients with primary generalized seizures. In the present study we did not observe increased excitation or decreased inhibition in the seizure-active brains of epileptics, as far as the CSF levels of amino acids reflect their levels in the brain.

Topiramate increases brain GABA, homocarnosine, and pyrrolidinone in patients with epilepsy

“…10,11 Some studies of patients treated with valproate report increased CSF GABA concentrations, but others do not. [12][13][14][15] Edited GABA measurements made using nuclear MR spectroscopy (NMRS) show no distinct increase with any of these four AEDs. 16 Brain GABA concentrations are below normal in many patients with frequent seizures.…”

“…Carbamazepine does not raise GABA. 11,14,16 Based on these results, serial measurements were made in nine patients as topiramate was started. Figure 1.…”

Kinetics of Glutamate and .GAMMA.-Aminobutyric Acid in Cerebrospinal Fluid in a Canine Model of Complex Partial Status Epilepticus induced by Kainic Acid

“…Sci. 66(12): 1555-1559, 2004 It is well accepted that glutamate (GLU) and aspartate (ASP) are the main excitatory amino acids in the brain, while γ-aminobutyric acid (GABA) functions as an inhibitory neurotransmitter [9,15]. An imbalance between excitatory and inhibitory amino acids has been hypothesized as a possible mechanism for epileptic seizures, thus amino acid analysis in the cerebrospinal fluids (CSFs) has been employed for understanding the pathogenesis of epilepsy.…”

Amino Acid Levels in the Cerebrospinal Fluid of Newly Diagnosed Epileptic Patients: Effect of Vigabatrin and Carbamazepine Monotherapies

“…Available data on CSF amino acid levels in patients with epilepsy are inconsistent, perhaps because they mainly come from chronic patients who have been treated for years with different antiepileptic drugs. GABA levels in CSF have been reported to be decreased (Wood et al, 1979;Manyam et al, 1980) or unchanged (Pitkanen et al, 1989) in chronic patients compared with controls. We did not observe any change in the GABA level.…”

“…Glutamate levels have been reduced (Mutani et al, 1974), normal (Araki et al, 1988;Pitkanen et al, 1989), or increased (Plum, 1974) compared with controls. Aspartate levels have been lower (Crawford and Chadwick, 1987;Pitkanen et al, 1989), normal (Mutani et al, 1974;Araki et al, 1988), or higher (Plum, 1974;Engelsen and Elsayed, 1984). The few previous observations of elevated levels of the excitatory amino acid glutamate in CSF of epileptic patients may have several explanations.…”