[Acoustic brain stem evoked potentials in patients in patients with different forms of acute tick-borne encephalitis]

Acoustic brain stem evoked potentials (ABSEP) have been investigated in 90 patients with different types of tick-borne encephalitis, in acute and remote stages. In all types of tick-borne encephalitis structural alterations mainly concerned II, III, IV and V complexes; changes of peak III, V latencies and interpeak I-III, I-V intervals have been detected as well. Focal type with multilevel CNS affection was distinguished by interpeak interval (III-V) elongation, higher per cent of abnormal III, V complexes and changes in wave amplitude V/I ratio. Stabilization of the peak latency and interpeak intervals in fever type occurred in 1-2 months, in meningeal type--in 2-3 months, in focal type--in 6-12 months. In several cases the ABSEP appearance preceded a focal type development, positive ABSEP dynamics was behind local neurological symptom regress. ABSEP method in acute tick-borne encephalitis allows predicting disease dynamics and outcome, conducting timely treatment correction and adequate rehabilitation, and substantiating optimal terms of out-patient clinical control in different types of the disease.