Erratum: A Novel Acute Discogenic Myelopathy Model Using Merocel® Sponge: Comparison With Clip Compression Model in Rats.

[This corrects the article on p. 204 in vol. 19, PMID: 37431382.].

Ruptured Fusiform Anterior Cerebral Artery Aneurysm in an Infant : Case Report and a Literature Review.

Ruptured intracranial aneurysms in infants are rare and infantile fusiform anterior cerebral artery (ACA) aneurysms are much rarer. In this report, we described the case of a 7-month-old infant with a ruptured fusiform ACA aneurysm who presented with seizure and underwent endovascular treatment. The patient was initially in a coma and the neurologic condition did not improve after treatment. The clinical characteristics of the case and literature review were discussed.

A Novel Acute Discogenic Myelopathy Model Using Merocel® Sponge: Comparison With Clip Compression Model in Rats.

Objective: Animal models of spinal cord injuries (SCIs) use rats to simulate human SCIs. Among the various techniques, clips have been used to reproduce the compression-contusion model. However, the mechanism of injury in discogenic incomplete SCI may differ from that in clip injury; however, a model has yet to be established. Previously, we issued a patent (No. 10-2053770) for a rat SCI model using Merocel®, a water-absorbing self-expanding polymer sponge. The objectives of this study were to compare the locomotor and histopathological changes between the Merocel®-compression model (MC group) and clip compression model (clip group). Methods: This study included 4 groups of rats: MC (n=30), MC-sham (n=5), clip (n=30), and clip-sham (n=5). Locomotor function was evaluated in all groups using the Basso, Beattie, and Bresnahan (BBB) scoring system, 4 weeks after injury. Histopathological analyses included morphology, presence of inflammatory cells, microglial activation, and extent of neuronal damage, which were compared among the groups. Results: The BBB scores in the MC group were significantly higher than those in the clip group throughout the 4 weeks (p<0.01). Neuropathological changes in the MC group were significantly less severe than those in the clip group. In addition, motor neurons were well preserved in the ventral horn of the MC group but poorly preserved in the ventral horn of the clip group. Conclusion: The novel MC group can help elucidate the pathophysiology of acute discogenic incomplete SCIs and may be applied in various SCI therapeutic strategies.

Chiari Malformation with Surgically Induced Open Neural Tube Defect in Late Chick Embryos : Characterization by Magnetic Resonance Imaging and Histopathological Analysis.

OBJECTIVE: Chiari II malformation (CM II) is still the main cause of severe morbidity and mortality in children with open neural tube defects (ONTDs). The goal of this study was to validate a CM II model in late-stage chick embryos with surgically induced ONTDs. METHODS: To make the chick embryo model of ONTD, their neural tubes were opened for a length of 5-6 somites at the thoracic level in Hamburger and Hamilton stage 18 chick embryos (n=150). They were reincubated in ovo. up to a total age of 17-21 days. A total of 19 embryos survived and were assigned to either the postoperative day (POD) 14-15 group (n=6) or the POD 17-18 group (n=13). Magnetic resonance imaging (MRI) and histopathologic findings of embryo heads with spinal ONTDs were compared with age-matched normal chick embryos. RESULTS: The chick embryos with ONTDs demonstrated definite and constant structural changes, such as downward displacement of the cerebellum to just above the foramen magnum and narrow and small cerebrospinal fluid spaces in the crowded small posterior fossa. These morphologic features were more prominent in the POD 17-18 group than in the POD 14-15 group. CONCLUSION: This is the first description of CM II with spinal ONTD in a late-stage chick embryo model with MRI and histopathological analysis. The morphological changes of the posterior fossa in this study mimic those of CM II associated with spinal ONTD in humans. This model will facilitate investigation of the pathogenesis of CM II.

Development and Growth of the Normal Cranial Vault : An Embryologic Review.

Understanding the development of a skull deformity requires an understanding of the normal morphogenesis of the cranium. Craniosynostosis is the premature, pathologic ossification of one or more cranial sutures leading to skull deformities. A review of the English medical literature using textbooks and standard search engines was performed to gather information about the prenatal development and growth of the cranial vault of the neurocranium. A process of morphogenic sequencing begins during prenatal development and growth, continues postnatally, and contributes to the basis for the differential manner of growth of cranial vault bones. This improved knowledge might facilitate comprehension of the pathophysiology of craniosynostosis.

Clinical significance of cerebral microbleeds locations in CADASIL with R544C NOTCH3 mutation.

BACKGROUND AND PURPOSE: Although cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common single-gene disorder of cerebral small blood vessels caused by NOTCH3 mutations, little has been described about the variation in the clinical findings between its underlying types of mutations. In particular, the presence of cerebral microbleeds (CMBs) has been an increasingly recognized magnetic resonance imaging finding in CADASIL, but their clinical significance is not clear. The purpose of this study is to assess whether CMBs are associated with symptomatic stroke in the CADASIL patients with R544C mutation and to compare the cerebral distribution of CMBs between CADASIL patients with and without symptomatic stroke. METHODS: This is a cohort study of patients who were diagnosed with genotype-confirmed R544C-mutation CADASIL. Primary neurologic symptoms were recorded. Symptomatic strokes were defined as transient ischemic attack, ischemic strokes and hemorrhagic strokes. CMBs were defined as focal areas of round signal loss on T2*-weighted gradient echo planar images with a diameter of less than 10 mm. The locations of CMBs were divided into lobar, basal ganglia, thalamus, brain stem and cerebellum. Multiple logistic regressions were performed to identify the epidemiologic or vascular risk factors associated with symptomatic stroke in patients with CADASIL. RESULTS: Among total of 51 subjects in this cohort, CMBs were present in 20 of 32 patients (64.5%) in the symptomatic stroke-group and in 8 of 19 patients (42.1%) in the non-stroke group (p = 0.16). CMBs were observed more frequently in the basal ganglia (p<0.001) and the cerebellum (p<0.018) in the symptomatic stoke group compared to the non-stroke group. The mean number of CMBs was significantly higher in the symptomatic stroke group (15.4±18.0 lesions per patients with CMBs) versus those without symptomatic stroke (3.3±3.0 lesions per patients with CMBs) (p = 0.003). Hypertension was an independent risk factor for symptomatic stroke in CADASIL (p = 0.014). It was independently associated with CMBs locations as basal ganglia (p = 0.016), thalamus (p = 0.010), brainstem (p = 0.044), and cerebellum (p = 0.049). However, It was not independently associated with CMBs on lobar lesion (p = 0.152). CONCLUSIONS: In this study hypertension was an independent predictor of CMBs presence in specific brain locations, as well as symptomatic stroke in the CADASIL patients. The distribution and burden of CMBs might be a clinically useful marker for the risk of symptomatic stroke. However, further prospective studies on the relationship between CMBs distribution and symptomatic stroke are required in order to support these preliminary findings.

Transient activation of an adaptor protein, disabled-2, in rat spinal cord injury.

We previously reported that disabled-2 (Dab-2), a cytosolic adaptor protein, was expressed in inflammatory and glial cells in the central nervous system (CNS) in experimental autoimmune encephalomyelitis and cerebral cryoinjury. Here, to determine the pattern of Dab-2 expression in a clip compression-induced rat spinal cord injury (SCI) model, the protein level and localization of Dab-2 in the spinal cord were investigated in rats with SCI using Western blotting and immunohistochemistry. Western blotting revealed that the expression of both the 75- and 100-kDa isoforms of Dab-2 peaked significantly in the spinal cord after clip compression injury 7 days post-injury compared to sham controls, and declined slightly thereafter. Immunohistochemistry revealed weak Dab-2 immunostaining in some neurons, glial cells, and ependymal cells in the spinal cords of the control animals, compared to staining in the macrophages and reactive astrocytes in lesions of the SCI animals. Overall, these findings suggest that both isoforms of Dab-2 are transiently upregulated in response to SCI and that the increased expression of Dab-2 is associated with the early activation of macrophages and astrogliosis in the course of CNS inflammation.

Immunohistochemical analysis of activin A expression in spinal cords of rats with clip compression injuries.

Activin A, a member of the TGF-ß superfamily, plays roles in neuroprotection and immunomodulation. In the present study, activin A expression was investigated on days 1, 4 and 7 post-injury in female adult Sprague-Dawley rats with spinal cord injuries (SCIs). The spinal cord was compressed with a vascular clip for 1 min following laminectomy at T9/T10. Western blot analysis showed that activin A levels peaked in SCI core lesions 4 days post-injury (p<0.01) and fell thereafter until day 7. Immunohistochemically, activin A was constitutively expressed in vascular endothelial cells, astrocytes and neurons of sham-operated controls, and in macrophages and reactive astrocytes of lesional cores and peripheries. As activin A plays an immunomodulatory role in the early stages of SCI and facilitates behavioral improvement, we postulate that transient upregulation of activin A in SCI tissue may contribute to modulation of inflammation development during SCI, thus leading to neuroprotection.

Demonstration of traumatic subarachnoid hemorrhage from the anterior choroidal artery.

We present a case of angiographically confirmed transection of the cisternal segment of the anterior choroidal artery (AChA) associated with a severe head trauma in a 15-year old boy. The initial brain computed tomography scan revealed a diffuse subarachnoid hemorrhage (SAH) and pneumocephalus with multiple skull fractures. Subsequent cerebral angiography clearly demonstrated a complete transection of the AChA at its origin with a massive extravasation of contrast medium as a jet trajectory creating a plume. We speculate that severe blunt traumatic force stretched and tore the left AChA between the internal carotid artery and the optic tract. In a simulation of the patient's brain using a fresh-frozen male cadaver, the AChA is shown to be vulnerable to stretching injury as the ipsilateral optic tract is retracted. We conclude that the arterial injury like an AChA rupture should be considered in the differential diagnosis of severe traumatic SAH.

An ideal model of informed consent communication.

Informed consent (IC) should be a form of communication between a physician and patient in which information regarding all options of a medical procedure and the patient's preference is shared. The aim of this study was to create a standard for communication by IC for physicians. The IC standard was developed based on an analysis of a dialogue in our previous experience with a medical communication program and a review of the literature. The dialogue pattern of the IC standard had the following six elements: opening; orientation; disclosure of information; conforming and complementing; shared decision making; and closing. Factors that influenced effective IC-based communication included preparation, attitude, empathy, listening, a psychosocial factor, nonverbal communication, explanation, and understanding. The IC communication standard will be useful in improving the quality of communication between a physician and patient in obtaining IC. It will also be used as a guideline for communication educators and medical students. Innovative strategies and rigorous studies are needed to improve IC counseling to establish effective patient-centered interviews.

Experimental models of spinal open neural tube defect and Chiari type II malformation.

INTRODUCTION: Experimental animal models are essential for investigation of the pathoembryogenesis, pathophysiology, and management strategy of spinal open neural tube defect (ONTD) and its associated anomalies including Chiari type II malformation. Genetic, chemical/nutrient, and surgical models have been widely used for a variety of purposes. The aim of this article is to review the representative animal models of spinal ONTD and associated Chiari type II malformation with respect to their advantages and disadvantages. DISCUSSION: Among them, the surgical model was described in detail because it is familiar to neurosurgeons and it is used for evaluations of prenatal repair of spinal ONTDs. The surgical model also has advantages because it allows quantitative analysis of the lesions. A description of our previous studies on spinal ONTDs using a chick surgical model is presented as an example.

Precedence of Parenchymal Enhancement on CT Angiography to a Fatal Duret Hemorrhage.

We report a case of fatal duret hemorrhage (DH) in a patient with acute tentorial subdural hematoma and bilateral chronic subdural hematoma along the cerebral hemispheres. Preoperative CT angiography (CTA) revealed prominent parenchymal enhancement in the ventral pontomesencephalic area. After burr-hole drainage, a large hemorrhage developed in this area. The parenchymal enhancement in the CTA may reflect the pontomensencephalic perforating vessel injury, and may be a sign of impending DH of acute transtentorial downward herniation. Previous use of aspirin and warfarin might have potentiated the process of DH and increase the extent of the bleed.

Potential role of fibronectin in microglia/macrophage activation following cryoinjury in the rat brain: an immunohistochemical study.

To investigate whether fibronectin, a high-molecular weight glycoprotein of the extracellular matrix (ECM), plays a role in the activation of microglia/macrophages after brain injury, we examined the changes in fibronectin and arginase-1, a marker for alternatively activated macrophages, in a rat cryoinjury model using Western blot analysis, real-time reverse transcription PCR and immunohistochemistry. The protein and mRNA level of fibronectin and arginase-1 significantly increased in the injury site of the ipsilateral cerebral cortex at days 4 and 7 after cryoinjury but was decreased at day 14. The immunohistochemical analysis revealed fibronectin expression in ED1-positive microglia/macrophages and reactive astrocytes, in the lesion core and periphery, respectively. Fibronectin immunoreactivity in the lesion was similar to arginase-1 except that fibronectin was detected in the ECM after cryoinjury. The present results suggest that fibronectin was extravasated into injured brain lesions via an impaired blood-brain barrier and stimulated glial cells including microglia and infiltrating macrophages in the lesion core and periphery to become alternatively activated microglia/macrophages, which modulated CNS inflammation after brain injury.

Subacute course of common iliac arterial laceration in lumbar disc surgery.

Vascular injuries in lumbar disc surgery are serious complications which may be overlooked due to a broad range of clinical manifestations. It is important to be aware of the perioperative implications of this rare occurrence to lower mortality risk. A 20-yr-old man with a right L4-5 lumbar disc protrusion was operated on routinely under a surgical microscope. A bloody surgical field was noted temporarily during a discectomy along with a decreased blood pressure. After fluid resuscitation with an ephedrine injection, the bleeding soon stopped spontaneously and his vital signs were stabilized. Fifty hours after the operation, the patient showed signs of hypovolemic hypotension with abdominal distension. The right femoral artery pulsation was absent on palpation. An enhanced CT angiography revealed a retroperitoneal hematoma and obstruction of the left common iliac artery. An urgent laparotomy was done to repair the injured vessel by excision and interposition of a graft. The patient had an uneventful recovery.The subacute course of deterioration might have been due to intermittent blood leakage from the lacerated common iliac artery, which was sealed spontaneously. It is very important to pay close attention to post-surgical clinical manifestations to avoid a potentially fatal outcome in lumbar disc surgery.

Alternatively activated macrophages in spinal cord injury and remission: another mechanism for repair?

Tissues within the central nervous system (CNS) have generally been regarded as immunologically privileged. However, in recent decades, it has been shown that immune reactions in the CNS continuously occur via various types of inflammation following autoimmune diseases and mechanical insults such as spinal cord injury (SCI). Among the various inflammatory cells associated with CNS disease, activated macrophages are classically known to induce detrimental consequences that are mediated by the secretion of pro-inflammatory molecules. Alternatively activated macrophages have recently been shown to modulate various types of CNS inflammation, including SCI. This review summarizes the potential roles of alternatively activated macrophages in the course of CNS inflammation in rodent SCI models.

Multiple liver abscesses associated with ventriculoperitoneal shunt infection: case report and review of the literature.

Liver abscess following ventriculoperitoneal (VP) shunting occurs very rarely. We report an unusual case of multiple liver abscesses caused by Staphylococcus capitis in a 50-year-old compromised woman due to a complicating VP shunt infection. We reviewed the nine cases of VP shunt complications reported in the English literature, and speculated that the most likely pathogenetic mechanism in our case is an infected peritoneal tip that migrated to and penetrated the liver, which subsequently caused the formation of multiple liver abscesses. The patient was successfully treated with percutaneous aspiration, drainage of the abscesses, intravenous antibiotics, and shunt revision. Awareness and vigilance of the possibility of liver abscess formation caused by VP shunt infection will help establish an early accurate diagnosis and therapeutic strategy.

Immunohistochemical study of arginase-1 in the spinal cords of rats with clip compression injury.

The expression of arginases, enzymes that catalyze the hydrolysis of arginine to ornithine and urea, was studied in the inflammatory lesions of spinal cord injury (SCI) in rats. The level of arginase-1 expression in rat spinal cords with clip compression injury was determined by Western blot analysis and immunohistochemistry. Western blot showed that the level of arginase-1 increased in the core lesion of SCI at day 1 post injury and continued to increase through days 4 (p<0.05) and 7 (p<0.01). Immunohistochemical analysis showed that arginase-1 was constitutively expressed in neurons and glial cells in sham control spinal cords. In SCI lesions, arginase-1 was additionally detected in inflammatory cells, particularly in isolectin B4-positive macrophages and reactive astrocytes within the core lesion. These findings suggest that the increased level of arginase-1 in SCI is associated with an increase in macrophages and reactive astrocytes, possibly contributing to the modulation of inflammation during the course of SCI.

Delayed herniation of coil loop and spontaneous reposition in a superior cerebellar artery aneurysm.

Herniation of coil loops into the parent artery is one of the complications of endovascular embolization with detachable coils. In this clinical setting, we cannot predict the consequence of the herniated coil loop. We report an unusual case of a superior cerebellar artery (SCA) aneurysm with delayed coil herniation into the basilar artery and spontaneous reposition into the SCA.

Morphometric study of the korean adult pituitary glands and the diaphragma sellae.

OBJECTIVE: To investigate the morphometric characteristics of the pituitary gland and diaphragma sellae in Korean adults. METHODS: Using the 33 formaline fixed adult cadavers (23 male, 10 female), the measurements were taken at the diaphragma sellae and pituitary gland. The authors investigated the relationship between dura and structures surrounding pituitary gland, morphometric aspects of pituitary gland and stalk, and morphometric aspect of central opening of diaphragma sellae. RESULTS: The boundary between the lateral surface of pituitary gland and the medial wall of cavernous sinus was formed by the thin dural layer and pituitary capsule. The pituitary capsule adherent tightly to the pituitary gland was observed to continue from the diaphragma sellae. Mean width, length, and height of the pituitary gland were 14.3 +/- 2.1, 7.9 +/- 1.3, and 6.0 +/- 0.9 mm in anterior lobes, and 8.7 +/- 1.7, 2.9 +/- 1.1, and 5.8 +/- 1.0 mm in posterior lobes, respectively. Although all dimensions of anterior lobe in female were slightly larger than those in male, statistical significance was noted in only longitudinal dimension. The ratio of posterior lobe to the whole length of pituitary gland was about 27%. The mean thickness of pituitary stalk was 2 mm. The diaphragmal opening was 5 mm or more in 26 (78.8%) of 33 specimen. The opening was round in 60.6% of the specimen, and elliptical oriented in an anterior-posterior or transverse direction in 39.4%. CONCLUSION: These results provide the safe anatomical knowledge during the transsphenoidal surgery and may be helpful to access the possibility of the development of empty sella syndrome.