Paradoxic Relations between Basilar Artery Reconfiguration and Superior Cervical Ganglia Ischemia After Bilateral Common Carotid Artery Ligation

The Enigma of Basilar Artery Dissections Secondary to Vasospasm Following Subarachnoid Hemorrhage. Exploration of the Unknown Effect of Superior Cervical Ganglia: A Preliminary Experimental Study

BACKGROUND

 Life-threatening basilar artery dissection (BAD) can be seen following subarachnoid hemorrhage (SAH), but it is not clear whether SAH causes dissection, or not. This study aims to investigate the relationship between degenerative changes in the superior cervical ganglia and the dissection rate of the basilar artery.

METHOD

 In this study, after 3 weeks of experimental SAH, animals were decapitated. Eighteen rabbits were divided into three groups according to their vasospasm indices. The basilar arteries were examined by anatomical and histopathologic methods.

RESULTS

 Basilar dissection with high vasospasm index (VSI) value (VSI > 3) was detected in six animals (group I); severe basilar edema and moderate VSI value (>2.4) were detected in seven rabbits (group II); and slight VSI value (<1.5) was detected in five subjects (group III). The degenerated neuron densities of the superior cervical ganglia were 12 ± 4 n/mm3 in group I, 41 ± 8 n/mm3 in group II, and 276 ± 78 n/mm3 in group III. The dissected surface values/lumen values were calculated as (42 ± 1)/(64 ± 11) in G-I, (21 ± 6)/(89 ± 17) in group II, and (3 ± 1)/(102 ± 24) in group III. If we look at these ratios as a percentage, it was 62% in group I, 23% in group II, and 5% in group III.

CONCLUSION

 Inverse relationship between the degenerated neuron densities of the superior cervical ganglia and the dissected surface values of the basilar artery was observed. Common knowledge is that BAD may lead to SAH; however, this study indicates that SAH is the cause of BAD.

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].

New Evidence for Regulatory Role of Trigeminal Ganglion on the Intraocular Pressure Following Subarachnoid Hemorrhage

BACKGROUND

 Increased intraocular pressure (IOP) likely secondary to an activated oculo-trigeminal reflex network is an important issue following subarachnoid hemorrhage (SAH). The relationship between the IOP and trigeminal ganglion (TGG) following experimental SAH was investigated in this study.

METHODS

 Twenty-three rabbits were used in this study. Five rabbits (n = 5) were used as the control group, another 5 as the sham group (n = 5), and the remaining 13 (n = 13) as the study group. The study group was further divided into two groups of animals with mild (n = 6) and severe (n = 7) TGG degeneration. The IOP values were recorded. After 2 weeks, the animals were decapitated. The mean degenerated neuron density of TGGs was estimated by stereological methods and analyzed statistically.

RESULTS

 The average IOP values were 11.85, 14.12, and 21.45 mm Hg in the control (n = 5), sham (n = 5), and study (n = 13) groups, respectively. The mean degenerated neuron density was 34, 237, and 3,165 mm3 in the control, sham, and study groups, respectively.

CONCLUSION

 According to the findings of this study, the experimental SAH leads to changes in IOP by affecting the TGG. By predicting and preventing IOP elevation in the setting of SAH, our findings will shed light on secondary sequelae such as glaucoma and irreversible blindness.

Loss of ganglioglomerular nerve input to the carotid body impacts the hypoxic ventilatory response in freely-moving rats

The carotid bodies are the primary sensors of blood pH, pO2 and pCO2. The ganglioglomerular nerve (GGN) provides post-ganglionic sympathetic nerve input to the carotid bodies, however the physiological relevance of this innervation is still unclear. The main objective of this study was to determine how the absence of the GGN influences the hypoxic ventilatory response in juvenile rats. As such, we determined the ventilatory responses that occur during and following five successive episodes of hypoxic gas challenge (HXC, 10% O2, 90% N2), each separated by 15 min of room-air, in juvenile (P25) sham-operated (SHAM) male Sprague Dawley rats and in those with bilateral transection of the ganglioglomerular nerves (GGNX). The key findings were that 1) resting ventilatory parameters were similar in SHAM and GGNX rats, 2) the initial changes in frequency of breathing, tidal volume, minute ventilation, inspiratory time, peak inspiratory and expiratory flows, and inspiratory and expiratory drives were markedly different in GGNX rats, 3) the initial changes in expiratory time, relaxation time, end inspiratory or expiratory pauses, apneic pause and non-eupneic breathing index (NEBI) were similar in SHAM and GGNX rats, 4) the plateau phases obtained during each HXC were similar in SHAM and GGNX rats, and 5) the ventilatory responses that occurred upon return to room-air were similar in SHAM and GGNX rats. Overall, these changes in ventilation during and following HXC in GGNX rats raises the possibility the loss of GGN input to the carotid bodies effects how primary glomus cells respond to hypoxia and the return to room-air.

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.

Early assessment of acute ischemic stroke in rabbits based on multi-parameter near-field coupling sensing

BACKGROUND

Early diagnosis and continuous monitoring are the key to emergency treatment and intensive care of patients with acute ischemic stroke (AIS). Nevertheless, there has not been a fully accepted method targeting continuous assessment of AIS in clinical.

METHODS

Near-field coupling (NFC) sensing can obtain the conductivity related to the volume of intracranial components with advantages of non-invasiveness, strong penetrability and real-time monitoring. In this work, we built a multi-parameter monitoring system that is able to measure changes of phase and amplitude in the process of electromagnetic wave (EW) reflection and transmission. For investigating its feasibility in AIS detection, 16 rabbits were chosen to establish AIS models by bilateral common carotid artery ligation and then were enrolled for monitoring experiments.

RESULTS

During the 6 h after AIS, the reflection amplitude (RA) shows a decline trend with a range of 0.69 dB and reflection phase (RP) has an increased variation of 6.48° . Meanwhile, transmission amplitude (TA) and transmission phase (TP) decrease 2.14 dB and 24.29° , respectively. The statistical analysis illustrates that before ligation, 3 h after ligation and 6 h after ligation can be effectively distinguished by the four parameters individually. When all those parameters are regarded as recognition features in back propagation (BP) network, the classification accuracy of the three different periods reaches almost 100%.

CONCLUSION

These results prove the feasibility of multi-parameter NFC sensing to assess AIS, which is promised to become an outstanding point-of-care testing method in the future.

Predictive role of trigeminal ganglion ischemia on scalp survival affected by temporal artery diameters: The first experimental study

Scalp arteries are mainly innervated by trigeminal, facial, and vagal nerves. The ischemic neurodegeneration of the trigeminal ganglion can impede scalp circulation via vasospasm-creating effects. This study was designed to investigate whether there is any link between the vasospasm index of deep temporal arteries and ischemic neuron densities of the trigeminal ganglion after subarachnoid hemorrhage. The study subjects included five normal control rabbits, six sham rabbits, and nine rabbits chosen from a formerly established experimental subarachnoid hemorrhage group created by cisternal homologous blood injection (0.75 mL). These rabbits, all male, were followed up for 3 weeks. The trigeminal ganglion and deep temporal artery vasospasm indexes were examined by stereological methods. Ischemic neuron densities of the trigeminal ganglion and vasospasm index values of deep temporal arteries were compared statistically. Postmortem examinations showed important vasospasms of deep temporal arteries, foramen magnum herniations, and neurodegeneration of the trigeminal ganglion. The mean vasospasm index values and degenerated neuron densities of the trigeminal ganglion were determined as 1.03 ± 0.13 and 10 ± 3/mm³ (p > 0.5) in the control group, 1.21 ± 0.18 and 35 ± 9/mm³ in the sham group (p < 0.005 for sham vs. control), and 2.54 ± 0.84 and 698 ± 134/mm³ in the experimental group (p < 0.0005 for sham vs. control and p < 0.00001 for study vs. control). There was an inverse relationship between the vasospasm index values and the degenerated neuronal density of the trigeminal ganglion. The high degenerated neuron density in the trigeminal ganglion had a facilitative effect on temporal artery vasospasm. Trigeminal ganglion neurodegeneration may promote temporal artery vasospasms after subarachnoid hemorrhage, which has not been previously mentioned in the literature.