Daily urinary excretion of catecholamines, DOPA, 5-HIAA and the levels of HVA, 5-HIAA in the cerebrospinal fluid of epilepsy patients - the discussion of the pathogenesis of depression and toxic serotonin syndrome
Hypo- or hyperactivity of the monoaminergic systems (serotonin, 5-HT; norepinephrine, NE; dopamine, DA) forms the basis of the pathogenesis of depression, which is one of the dangerous syndromes associated with epilepsy. Polypharmacy of depression with selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, and tricyclic antidepressants sometimes transforms depression into toxic serotonin syndrome, that is frequently fatal (particularly, with concomitant use of carbamazepine). The measurements of daily urinary excretion and cerebrospinal fluid (CSF) levels of monoamines and its catabolites allows to control the activity of monoamine neurotransmitter systems, adjust therapeutic regiments and avoid complications. In epilepsy, the activity of all monoaminergic systems is decreased in 28% of cases (0.5-1.2-fold); in 25% of cases the activity of serotonin system is predominant (2.2-fold, and the activity of catecholamine systems is close to normal); in 48% of cases the activity of all monoaminergic systems is increased by 25-50% and is relatively balanced. The epinephrine system is independent; it is activated in 75% of the cases (2.8-3.3-fold) and close to normal (increased by 15%) in 25% of the cases, and rarely (8 out of 71 cases) it is decreased 2.6-fold on a background of a marked decrease in all others monoaminergic systems. To correct the imbalance in depression, it is advisable to use: selective serotonin reuptake inhibitors (SSRI), when serotonin activity is deficient; selective inhibitors of NE and DA reuptake, when norepinephrine and dopamine neurotransmission is deficient; tricyclic antidepressants, monoamine oxidase inhibitors, and drugs inhibiting reuptake of both NE and 5-HT (under the control of the levels of these systems metabolites) when the activity of all monoamine systems is decreased; medications controlling the cortisol level in blood, when epinephrine system is overactive.