Uncovering a New Cause of Obstructive Hydrocephalus Following Subarachnoid Hemorrhage: Choroidal Artery Vasospasm–Related Ependymal Cell Degeneration and Aqueductal Stenosis—First Experimental Study

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 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.

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.

Therapeutic Approaches for Cerebrovascular Dysfunction After Aneurysmal Subarachnoid Hemorrhage: An Update and Future Perspectives

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe subtype of stroke occurring at a relatively young age with a significant socioeconomic impact. Treatment of aSAH includes early aneurysm exclusion, intensive care management, and prevention of complications. Once the aneurysm rupture occurs, blood spreading within the subarachnoid space triggers several molecular pathways causing early brain injury and delayed cerebral ischemia. Pathophysiologic mechanisms underlying brain injury after aSAH are not entirely characterized, reflecting the difficulties in identifying effective therapeutic targets for patients with aSAH. Although the improvements of the last decades in perioperative management, early diagnosis, aneurysm exclusion techniques, and medical treatments have increased survival, vasospasm and delayed cerebral infarction are associated with high mortality and morbidity. Clinical practice can rely on a few specific therapeutic agents, such as nimodipine, a calcium-channel blocker proved to reduce severe neurologic deficits in these patients. Therefore, new pharmacologic approaches are needed to improve the outcome of this life-threatening condition, as well as a tailored rehabilitation plan to maintain the quality of life in aSAH survivors. Several clinical trials are investigating the efficacy and safety of emerging drugs, such as magnesium, clazosentan, cilostazol, interleukin 1 receptor antagonists, deferoxamine, erythropoietin, and nicardipine, and continuous lumbar drainage in the setting of aSAH. This narrative review focuses on the most promising therapeutic interventions after aSAH.

Roles of Ependymal Cells in the Physiology and Pathology of the Central Nervous System

Ependymal cells are indispensable components of the central nervous system (CNS). They originate from neuroepithelial cells of the neural plate and show heterogeneity, with at least three types that are localized in different locations of the CNS. As glial cells in the CNS, accumulating evidence demonstrates that ependymal cells play key roles in mammalian CNS development and normal physiological processes by controlling the production and flow of cerebrospinal fluid (CSF), brain metabolism, and waste clearance. Ependymal cells have been attached to great importance by neuroscientists because of their potential to participate in CNS disease progression. Recent studies have demonstrated that ependymal cells participate in the development and progression of various neurological diseases, such as spinal cord injury and hydrocephalus, raising the possibility that they may serve as a potential therapeutic target for the disease. This review focuses on the function of ependymal cells in the developmental CNS as well as in the CNS after injury and discusses the underlying mechanisms of controlling the functions of ependymal cells.

Relationship between subarachnoid and central canal hemorrhage and spasticity: A first experimental study

Objective: Spastic disorders are considered as important cerebral complications of subarachnoid hemorrhage (SAH). However, there has been no research concerning the pathophysiological mechanism of its link with the spinal cord. The present study aimed to assess the relationship between the development of spasticity and neuronal degeneration after SAH and increase in spinal cord pressure after central canal hemorrhage (CCH).Participants: Twenty-three rabbits were included.Outcome measures: Of all rabbits, 5, 5, and 13 were allocated in the control, SHAM and study groups, respectively. Moreover, 1 cc of saline and 1 cc of autologous arterial blood were injected into the cisterna magna of the SHAM and study groups, respectively. The Muscle spasticity tension values (MSTVs) were determined according to the modified Ashworth scale. Degenerated neuron densities (DND) in the gray matter (GM) of each animal's spinal cord were stereologically calculated.Results: The average MSTV of each group was as follows: control group (n = 5) 2; SHAM group (n = 5) 3-5; and study group (n = 13) 8-10. The DND values of the spinal cord of each group were as follows: control group, 2 ± 1/mm³; SHAM group, 12 ± 3/mm³; and study group, 34 ± 9/mm³. Results showed an important linear relationship between the MSTVs and the DND of the spinal cord (P < 0.001).Conclusion: Spasticity may be attributed to other causes such as ischemic neurodegenerative process that develops after spinal SAH and the de-synchronization of the flexor-extensor muscles due to the spontaneous discharge of interneuronal structures, which are crossed within the spinal cord owing to the build-up of pressure after CCH.

Important interaction between urethral taste bud-like structures and Onuf's nucleus following spinal subarachnoid hemorrhage: A hypothesis for the mechanism of dysorgasmia

BACKGROUND

We previously postulated that orgasmic sensation may occur through recently discovered genital taste bud-like structures. The interaction between the pudendal nerve and Onuf's nucleus may be important for developing orgasmic information. The study aims to investigate whether ischemic damage to Onuf's nucleus-pudendal network following spinal subarachnoid hemorrhage (SAH) causes taste bud degeneration or not.

METHODS

The study was conducted on 22 fertile male rabbits who were divided into three groups: control (GI; n=5), SHAM (GII; n=5) and study (GIII; n=12). Isotonic solution, .7cm³, for the SHAM, and .7cm³ homologous blood was injected into spinal subarachnoid spaces at S2 level of the study group. Two weeks later, Onuf's nucleus, pudendal ganglia and the taste bud-like structures of the penile urethra were examined histopathologically. Degenerated neuron densities of Onuf's nucleus, pudendal ganglia and atrophic taste bud-like structures were estimated per mm³ and the results analyzed statistically.

RESULTS

The mean degenerated neuron densities of taste bud-like structures, Onuf's nucleus and pudendal ganglia were estimated as 2±1/mm³, 5±1/mm³, 6±2/mm³ in GI; 12±4/mm³, 35±9/mm³, 188±31/mm³, in GII and 41±8/mm³, 215±37/mm³, 1321±78/mm³, in GIII. Spinal SAH induced neurodegeneration in Onuf's nucleus, pudendal ganglia and taste bud atrophy was significantly different between GI/GII (p<.005); GII/GIII (p<.0005) and GI/GIII (p<.0001).

CONCLUSION

Ischemic neuronal degenerations of Onuf's nucleus and pudendal ganglia following spinal SAH lead to genital taste bud-like structure atrophy. This mechanism may be responsible for sexual anhedonia and sterility in cases with spinal cord injury, which has not been documented so far. More studies are needed.

Efficacy of translamina terminalis ventriculostomy tube in prevention of chronic hydrocephalus after aneurysmal subarachnoid hemorrhage

Background

Chronic shunt-dependent hydrocephalus is still a common complication after aneurysmal SAH (aSAH) and is associated with increased morbidity. Pathology of chronic shunt-dependent hydrocephalus after aSAH is complex and multifactorial which makes its prevention challenging. We thought to evaluate whether external ventricular drainage (EVD) through fenestrated lamina terminalis would decrease the rate of chronic shunt-dependent hydrocephalus after aSAH.

Methods

A retrospective analysis of 68 consecutive patients with aSAH who underwent microsurgical clipping of the ruptured aneurysm. Patients were divided into two groups: Group A included patients with lamina terminalis fenestration without insertion of ventriculostomy tube and Group B included patients with EVD through fenestrated lamina terminalis. Demographic, clinical, radiological, and outcome variables were compared between groups.

Results

Group A comprised 29 patients with mean age of 47.8 years and Group B comprised 39 patients with mean age of 46.6 years. Group B patients had statistically significant (P < 0.05) lower incidence of chronic shunt- dependent hydrocephalus than Group A patients (30.8% vs. 55.2%, respectively).

Conclusion

EVD through fenestrated lamina terminalis is safe and may be effective in decreasing the incidence of chronic shunt-dependent hydrocephalus after aSAH.

What Are We Missing From Asymmetric Relationship Between the Retinal Nerve Fiber Layer Thickness Profiles and Sphenoid Sinus Volume?

PURPOSE/AIM OF THE STUDY

Detailed analysis of retinal structure such as the retinal nerve fiber layer can be performed by spectral-domain optical coherence tomography (OCT). There are no published studies concerning a relationship between retinal nerve fiber layer and human sphenoid sinus volumes. We investigated this relationship.

MATERIAL AND METHODS

Spectral-domain OCT. The peripapillary retinal nerve fiber layer (RNFL) thickness and sphenoid sinus volume estimation of both sides of sex-matched patients were retrospectively analyzed.

RESULTS

The mean RNFL thicknesses at the left side (91.8 μm) were significantly smaller than the right side (94.5 μm) (P = 0.040). However, the mean left sinus volume (44.5 cm) is larger than the right side, (34.5 mm) (P < 0.005). Left and right differences of both parameters are statistically significant (P < 0.05).

CONCLUSION

There is a negative correlation between mean RNFL thicknesses and mean sinus volumes. To our knowledge, this article is the first report demonstrating the asymmetry relationship between RNFL and sphenoid sinus volumes.

Choroid plexus and the blood-cerebrospinal fluid barrier in disease

The choroid plexus (CP) forming the blood-cerebrospinal fluid (B-CSF) barrier is among the least studied structures of the central nervous system (CNS) despite its clinical importance. The CP is an epithelio-endothelial convolute comprising a highly vascularized stroma with fenestrated capillaries and a continuous lining of epithelial cells joined by apical tight junctions (TJs) that are crucial in forming the B-CSF barrier. Integrity of the CP is critical for maintaining brain homeostasis and B-CSF barrier permeability. Recent experimental and clinical research has uncovered the significance of the CP in the pathophysiology of various diseases affecting the CNS. The CP is involved in penetration of various pathogens into the CNS, as well as the development of neurodegenerative (e.g., Alzheimer´s disease) and autoimmune diseases (e.g., multiple sclerosis). Moreover, the CP was shown to be important for restoring brain homeostasis following stroke and trauma. In addition, new diagnostic methods and treatment of CP papilloma and carcinoma have recently been developed. This review describes and summarizes the current state of knowledge with regard to the roles of the CP and B-CSF barrier in the pathophysiology of various types of CNS diseases and sets up the foundation for further avenues of research.

A new experimental evidence that olfactory bulb lesion may be a causative factor for substantia nigra degeneration; preliminary study

Background: Anosmia has been considered as the first diagnostic criteria of Parkinson disease (PD), we investigated the effect of the olfactory bulbectomy (OBX) on histopathological features of the substantia nigra in an animal model.Methods: Twenty-seven male rats were used in this study. Animals were divided into three groups as five (control), six SHAM and sixteen study (OBL) groups. Nothing was done in the control group, the only burr hole was done in the SHAM group, OBL was not applied, and bilateral OBL was performed in the study group, and followed ten weeks, then animals were decapitated. Olfactory bulb volumes were measured by macro anatomically. The olfactory bulbs and substantia nigra sections were analyzed by a stereological method to evaluate olfactory glomerulus and neuron density of substantia nigra per cubic centimeter and compared with statistically.Results: The mean olfactory bulb volume, degenerated olfactory glomerulus density and degenerated neuron density of substantia nigra were measured as:(4.14 ± 0.20) mm³, (1 ± 1)/mm³ and (7 ± 2)/mm³ in control (Group I); (3.6 ± 0.16)/mm³, (4 ± 1)/mm³ and(32 ± 7)/mm³ in SHAM (Group II) and (2.2 ± 0.9)/mm³, (112 ± 18)/mm³ and (1543 ± 115)/mm³in study group (Group III). Diminished olfactory bulb volume was observed in Group III animals.Conclusions: We concluded that OBL may lead to the degeneration of substantia nigra.

First definition of burned choroid plexus in acidic cerebrospinal fluid-filled brain ventricles during subarachnoid hemorrhage: Experimental study

Blood and cerebrospinal fluid (CSF) acidosis is the most troubling complication in subarachnoid hemorrhage (SAH) if carotid body (CB) networks are disrupted. However, histopathological examination of the choroid plexus (CP) in acidic CSF has not been evaluated so far. In this study, we aimed to investigate the CP in acidic CSF following SAH. Twenty-eight rabbits were used. Five rabbits were used to analyze CB network (control group; n = 5); seven rabbits were injected 1 mL of saline (Sham group; n = 7); and the rest 16 rabbits were given 1 mL of autologous arterial blood inject into the cisterna magna to create SAH (SAH group; n = 16). Blood and CSF pH values were recorded before/during/after the experimental procedures. Nuclear darkening, cellular shrinkage and pyknosis suggested the presence of apoptosis of epithelial cells of CP. The densities of normal and degenerated epithelial cells of CPs were estimated using stereological methods. The relationship between the pH values and degenerated epithelial cell densities of CPs were statistically compared by Mann-Whitney U-test. The pH values of blood were estimated as 7.359 ± 0.039 in the control group, 7.318 ± 0.062 in the Sham group, 7.23 ± 0.013 in the SAH group. CSF pH values were 7.313 ± 0.028 in the control group, 7.296 ± 0.045 in the Sham group, and 7.224 ± 0.012 in the SAH group. Degenerated epithelial cell density of CP was 25 ± 7 in the control group, 226 ± 64 in the Sham group, and 2115 ± 635 in the SAH group. There was a considerable link between CSF pH values and degenerated epithelial cells of CP (P < 0.0001). This study shows that CB insult causes acidosis of CSF as well as cellular degeneration of CP during SAH. This is the first description of this in the literature.

Edaravone combined with cinepazide maleate on neurocyte autophagy and neurological function in rats with subarachnoid hemorrhage

Effects of edaravone combined with cinepazide maleate on neurocyte autophagy and neurological function in rats with subarachnoid hemorrhage were investigated. Eighty SD rats were selected to establish subarachnoid hemorrhage (SAH) rat models, which were divided into sham operation group, SAH group, MCI group and combined group. Hippocampal tissue of each group was taken to observe the number of neurocytes. The expression levels of Beclin-1 and (light chain LC3)-II of rats in each group were detected by ELISA. Pearson's correlation factors were used to analyze the correlation between Beclin-1 and LC3-11, and neurological function tests were carried out on rats of each group 14 and 28 days after administration. The morphological and structural damage of nerve cells in the combined group was further alleviated, and the survival rate of neurons significantly increased at all time points (P<0.05). The expression levels of Beclin-1 and LC3-11 in combined group was significantly higher than those in SAH group and CMI group (P<0.05), and Beclin-1 was positively correlated with LC3-11 (r=0.9454). Longa score of the combined group was significantly lower than that of the other two groups, and muscle strength score was significantly higher than that of the other two groups (P<0.05). Edaravone combined with cinepazide maleate can effectively increase the survival rate of brain cells and promote the volatilization of neurological function in the treatment of hemorrhage in the subretinal space of the omentum, which is worthy of popularization and application.

Lower Iron Levels Predict Acute Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

We tested the hypothesis that low serum iron levels are associated with acute hydrocephalus following aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Patients presenting with ruptured intracranial aneurysms were enrolled in the prospective observational study. Age, sex, history of diabetes, hypertension and hyperlipidemia, symptom onset, Fisher grade, Hunt-Hess grade, aneurysm location, hemoglobin, and serum iron were collected. Acute hydrocephalus was determined within 72 hours after subarachnoid hemorrhage. A propensity-score matching analysis was performed to correct imbalances in patient characteristics between hydrocephalus and non-hydrocephalus groups.

RESULTS

A total of 535 patients were included. Incidence of acute hydrocephalus was 20.0%. In multivariate logistic regression analysis, lower serum iron was considered as a risk factor of acute hydrocephalus, as well as delayed ischemic neurologic deficit and lower hemoglobin (P = 0.000). After propensity-score matching, lower serum iron was considered as an independent risk factor for acute hydrocephalus, whereas hemoglobin and delayed ischemic neurologic deficit were not. The matched hydrocephalus group had lower serum iron comparing with the matched non-hydrocephalus group (10.26 ± 5.33 mmol/L vs. 13.44 ± 5.18 mmol/L; P = 0.000). The optimal cut-off value for serum iron levels as a predictor for acute hydrocephalus in patients with aSAH was determined as 13.1 mmol/L in the receiver operating characteristic curve. Furthermore, lower serum iron levels (odds ratio 0.305; 95% confidence interval, 0.178-0.524; P = 0.000) and acute hydrocephalus (odds ratio 0.372; 95% confidence interval, 0.202-0.684; P = 0.001) were predictors of poor outcome, as well as higher Hunt-Hess grade and Fisher grade.

CONCLUSIONS

Lower serum iron levels after aSAH was a predictor of acute hydrocephalus and unfavorable outcome.

Hydrocephalus after Subarachnoid Hemorrhage: Pathophysiology, Diagnosis, and Treatment

Hydrocephalus (HCP) is a common complication in patients with subarachnoid hemorrhage. In this review, we summarize the advanced research on HCP and discuss the understanding of the molecular originators of HCP and the development of diagnoses and remedies of HCP after SAH. It has been reported that inflammation, apoptosis, autophagy, and oxidative stress are the important causes of HCP, and well-known molecules including transforming growth factor, matrix metalloproteinases, and iron terminally lead to fibrosis and blockage of HCP. Potential medicines for HCP are still in preclinical status, and surgery is the most prevalent and efficient therapy, despite respective risks of different surgical methods, including lamina terminalis fenestration, ventricle-peritoneal shunting, and lumbar-peritoneal shunting. HCP remains an ailment that cannot be ignored and even with various solutions the medical community is still trying to understand and settle why and how it develops and accordingly improve the prognosis of these patients with HCP.

Sudden death and cervical spine: A new contribution to pathogenesis for sudden death in critical care unit from subarachnoid hemorrhage; first report - An experimental study

Context:

Sudden death from subarachnoid hemorrhage (SAH) is not uncommon.

Aims:

The goal of this study is to elucidate the effect of the cervical spinal roots and the related dorsal root ganglions (DRGs) on cardiorespiratory arrest following SAH.

Settings and Design:

This was an experimental study conducted on rabbits.

Materials and Methods:

This study was conducted on 22 rabbits which were randomly divided into three groups: control (n = 5), physiologic serum saline (SS; n = 6), SAH groups (n = 11). Experimental SAH was performed. Seven of 11 rabbits with SAH died within the first 2 weeks. After 20 days, other animals were sacrificed. The anterior spinal arteries, arteriae nervorum of cervical nerve roots (C6–C8), DRGs, and lungs were histopathologically examined and estimated stereologically.

Statistical Analysis Used:

Statistical analysis was performed using the PASW Statistics 18.0 for Windows (SPSS Inc., Chicago, Illinois, USA). Intergroup differences were assessed using a one-way ANOVA. The statistical significance was set at P < 0.05.

Results:

In the SAH group, histopathologically, severe anterior spinal artery (ASA) and arteriae nervorum vasospasm, axonal and neuronal degeneration, and neuronal apoptosis were observed. Vasospasm of ASA did not occur in the SS and control groups. There was a statistically significant increase in the degenerated neuron density in the SAH group as compared to the control and SS groups (P < 0.05). Cardiorespiratory disturbances, arrest, and lung edema more commonly developed in animals in the SAH group.

Conclusion:

We noticed interestingly that C6–C8 DRG degenerations were secondary to the vasospasm of ASA, following SAH. Cardiorespiratory disturbances or arrest can be explained with these mechanisms.

First report of perforation of ligamentum flavum by sequestrated lumbar intervertebral disc

Disc fragments are well known to migrate to superior, inferior, or lateral sites in the anterior epidural space, posterior epidural migrated lumbar disc fragments is an extremely rare disorder, 61 cases have been reported to date. However, there were no cases with perforated ligamentum flavum (LF). We report a different case with perforation of ligamentum ligamentum by disc fragment. To the best of our knowledge, this is the first report of perforation LF by a posterior epidural migrated sequester disc.