Blink reflex changes in thalamic hemorrhage.

Electrical stimulation of the supraorbital nerve on one side evokes early reflex contraction of the orbicularis oculi muscle ipsilaterally (R1) and late reflexes bilaterally (direct-R2 and consensual-R2c). The Central pathway of the R1 may conduct through the pons but the exact Central pathvvay of the R2 is not entirely understood. İt has been presumed that the stimulus goes up to the opposite thalamus and/or cortex, than project down to bilateral facial nuclei. İn this study, the blink reflex was investigated in 13 patients with thalamic hemorrhage and in 12 normal subjects. R1 was normal on both side stimulation but R2 and R2c obtained by stimulation on the paretic side slo- wer in latency compared with responses of the non paretic side and the values of the normal subjects. İt is pre­ sumed that the thalamus may modulate the second component of the blink reflex.