Letter to the Editor Regarding the Manuscript of "The Longest Angiographic and Clinical Follow-Up of Microsurgically Treated Giant Intracranial Aneurysms: Experience with 70 Cases"

New experimental finding of dangerous autonomic ganglia changes in cardiac injury following subarachnoid hemorrhage; a reciprocal culprit-victim relationship between the brain and heart

OBJECTIVE

The vagal, stellate, and cardiac ganglia cells changes following subarachnoid hemorrhage (SAH) may occur. This study aimed to investigate if there is any relation between vagal network/stellate ganglion and intrinsic cardiac ganglia insult following SAH.

MATERIALS AND METHODS

Twenty-six rabbits were used in this study. Animals were randomly divided as control (GI, n = 5); SHAM 0.75 cc of saline-injected (n = 5) and study with autologous 1.5 cc blood injection into their cisterna magna(GIII, n = 15). All animals were followed for three weeks and then decapitated. Their motor vagal nucleus, nodose, stellate, and intracardiac ganglion cells were estimated by stereological methods and compared statistically.

RESULTS

Numerical documents of heart-respiratory rates, vagal nerve- ICG, and stellate neuron densities as follows: 276 ± 32/min-22 ± 3/min-10.643 ± 1.129/mm3-4 ± 1/mm3-12 ± 3/mm3 and 2 ± 1/cm3 in the control group; 221 ± 22/min-16 ± 4/min-8.699 ± 976/mm3-24 ± 9/mm3-103 ± 32/mm3 and 11 ± 3/cm3 in the SHAM group; and 191 ± 23/min-17 ± 4/min-9.719 ± 932/mm3-124 ± 31/mm3-1.542 ± 162/mm3 and 32 ± 9/cm3 in the SAH (study) group. The animals with burned neuro-cardiac web had more neurons of stellate ganglia and a less normal neuron density of nodose ganglia (p < 0.005).

CONCLUSION

Sypathico-parasympathetic imbalance induced vagal nerve-ICG disruption following SAH could be named as Burned Neurocardiac Web syndrome in contrast to broken heart because ICG/parasympathetic network degeneration could not be detected in classic broken heart syndrome. It was noted that cardiac ganglion degeneration is more prominent in animals' severe degenerated neuron density of nodose ganglia. We concluded that the cardiac ganglia network knitted with vagal-sympathetic-somatosensitive fibers has an important in heart function following SAH. The neurodegeneration of the cardiac may occur in SAH, and cause sudden death.Graphical abstract[Formula: see text].

Protective Felix-Culpa Effect of Superior Sympathetic Cervical Ganglion Degenerations on Prevention of Basilar Artery Spasm Following Subarachnoid Hemorrhage: A Preliminary Experimental Study

BACKGROUND

Posterior cerebral blood flow is regulated by the basilar arteries (BA). Its vasospasm of basilar arteries (BA) can occur following subarachnoid hemorrhage (SAH). Superior cervical sympathetic ganglia (SCG) fibers have a vasoconstrictor effect on the BA. We aimed to investigate the relationship between the degenerated neuron density of the SCG and the severity of BA vasospasm after experimental subarachnoid hemorrhage.

METHODS

Twenty-four rabbits were used. Five of them were used as the control group, and five of them were used as the SHAM group. Experimental subarachnoid hemorrhages were performed in the remaining fourteen animals (study group) by injecting homologous blood into cisterna magna. After three weeks of injection, neuron densities of SCG and the severity of BA vasospasm index values (VSI) were examined histopathologically and compared statistically.

RESULTS

The mean VSI was 0.669±0.1129 in the control group, 0.981±0.159 in the SHAM group, and 1.512±0.298 in the study group. The mean degenerated neuronal density of SCG was 436±79/mm³ in severe vasospasm (n=3), 841±101/mm³ in moderate vasospasm (n=4), and 1.921±849/mm³ in the less vasospasm detected animals (n=6).

CONCLUSION

This study shows an inverse relationship between the degenerated neuronal density in the SCG and VSI values. This finding indicates a diminished sympathetic input from the superior cervical ganglion (SCG) resulting in a beneficial (the Felix-culpa) effect by dilating the lumen diameter of the basilar artery (BA), so superior sympathetic cervical ganglion degeneration following SAH protects the basilar artery spasm.