Spinal Subarachnoid Hemorrhage Induced Intractable Miotic Pupil. A Reminder of Ciliospinal Sympathetic Center Ischemia Based Miosis: An Experimental Study

Özet

AIM: To examine ischemic neurodegeneration of the ciliospinal center on permanent miosis following subarachnoid hemorrhage(SAH).MATERIAL and METHODS: Nineteen rabbits were examined in this study. The animals were divided into three groups, as control(GI, n=5), sham (GII, n=5) and study group (GIII, n=9). Pupil diameters were measured after giving 0.5 mL physiological saline forsham and autologous arterial blood for the study group into the cervico-thoracic subarachnoid space. After three weeks of followup, the cervico-thoracic cord and bilateral superior cervical sympathetic ganglia were removed. The pupil diameter values werecompared with degenerated neuron volumes of sympathetic ganglia and degenerated neuron densities of thoracic sympatheticnuclei which were studied by stereological methods.RESULTS: The mean pupil diameter was 5180 ± 370 µm and the mean degenerated neuron density of the ciliospinal center was 4± 1/mm3 in animals of the control group (GI). These values were 9850 ± 610 µm, 10 ± 3/mm3 in sham (GII), and 7.010 ± 440 µm and98 ± 21/mm3 in the study (GIII) groups. There was an inverse relationship between degenerated neuron density of the ciliospinalnuclei and pupil diameters.CONCLUSION: We showed and reported for the first time that ciliospinal sympathetic center ischemia-induced neurodegenerationmay have been responsible for permanent miosis following SAH.