Letter to the Editor Regarding “Predictors of Shunt-Dependent Hydrocephalus After Aneurysmal Subarachnoid Hemorrhage? A Systematic Review and Meta-Analysis”

Important Finding for COVID-19 Pandemic: Hydrocephalus-producing effect of Vaporized Alcohol Disinfectant

BACKGROUND

 Alcohol exposure may cause hydrocephalus, but the effect of vaporized nasal alcohol exposure on the choroid plexus, and ependymal cells, and the relationship between alcohol exposure and developing hydrocephalus are not well known. This subject was investigated.

METHODS

 Twenty-four male (∼380 g) Wistar rats were used in this study. The animals were divided into three groups, as the control, sham and study groups. The study group was further divided into two groups as the group exposed to low or high dose of alcohol. The choroid plexuses and intraventricular ependymal cells and ventricle volumes were assessed and compared statistically.

RESULTS

 Degenerated epithelial cell density of 22 ± 5, 56 ± 11, 175 ± 37, and 356 ± 85/mm3 was found in the control, sham, low alcohol exposure, and high alcohol exposure groups, respectively. The Evans index was <34% in the control group, >36% in the sham group, >40% in the group exposed to low alcohol dose (low-dose alcohol group), and >50% in the group exposed to high dose of alcohol (high-dose alcohol group).

CONCLUSIONS

 It was found that alcohol exposure caused choroid plexus and ependymal cell degeneration with ciliopathy and enlarged lateral ventricles or hydrocephalus. In the COVID-19 pandemic era, our findings are functionally important, because alcohol has often been used for hygiene and prevention of transmission of the Sars-Cov-2-virus.

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.

New histopathological evidence for the relationship between hydromyelia and hydrocephalus following subarachnoid hemorrhage: An experimental study

Objectives

Subarachnoid hemorrhage (SAH) is a serious pathology with a high death and morbidity rate. There can be a relationship between hydromyelia and hydrocephalus following SAH; however, this subject has not been well investigated.

Materials and Methods

Twenty-four rabbits (3 ± 0.4 years old; 4.4 ± 0.5 kg) were used in this study. Five of them were used as the control, and five of them as the SHAM group. The remaining animals (n = 14) had been used as the study group. The central canal volume values at the C1-C2 levels, ependymal cells, numbers of central canal surfaces, and Evans index values of the lateral ventricles were assessed and compared.

Results

Choroid plexus edema and increased water vesicles were observed in animals with central canal dilatation. The Evans index of the brain ventricles was 0.33 ± 0.05, the mean volume of the central canal was 1.431 ± 0.043 mm3, and ependymal cells density was 5.420 ± 879/mm2 in the control group animals (n = 5); 0.35 ± 0.17, 1.190 ± 0.114 mm3, and 4.135 ± 612/mm2 in the SHAM group animals (n = 5); and 0.44 ± 0.68, 1.814 ± 0.139 mm3, and 2.512 ± 11/mm2 in the study group (n = 14). The relationship between the Evans index values, the central canal volumes, and degenerated ependymal cell densities was statistically significant (P < 0.05).

Conclusions

This study showed that hydromyelia occurs following SAH-induced experimental hydrocephalus. Desquamation of ependymal cells and increased cerebrospinal fluid secretion may be responsible factors in the development of hydromyelia.

Interesting negative correlation between transorbital optic nerve sheath diameter and Evans' index values; can it be predictive for failure of endoscopic third ventriculostomy?

Background: Currently, Endoscopic third ventriculostomy (ETV) is one of the commonly used surgical options for the treatment of non-communicating hydrocephalus but reported success rates from ETV vary considerably, and a reliable noninvasive means to detect the efficacy of ETV is still lacking. In this study, the changes in Evans's Index and the transorbital optic nerve sheath (ONSD) diameter measurement after endoscopic third ventriculostomy were compared. Methods: Preoperative and early postoperative ultrasonographic ONSD measurement and preoperative and postoperative 3 months Evans' index of patients with hydrocephalus on whom ETVs were performed between 1 February 2018 and 23 May 2022 and analyzed. Results: The chart of 8 male and 2 female patients was analyzed. Their median age at presentation was 5.3 years (range 1 - 14 years). Mean ONSD values were 5.66 mms in the preoperative period, which was decreased to a mean of 4.17 mms in the early postoperative period. The Evans' index was 0.5320 in the preoperative period; however, it decreased to 0.4460 in the postoperative 3rd months. The preoperative and early postoperative mean ONSD values and Evans' Index of patients were significantly different. Interestingly, a negative correlation was also observed between ONSD values and Evans' index. Conclusions: ONSD measurement and Evans' index have been commonly used after ETV procedures İn pediatric patients with hydrocephalus. Still, there is an unexplained negative correlation between ONSD and Evans' index values. This study indicates that the two measures (Evans's index and ONSD) should be considered when performing follow-up examinations in patients after ETV.