OBJECTIVE: Despite advance in the surgical treatment of the skull base lesions, reaching the ventral brain stem is not familiar to us yet. No traditional complex skull base approaches have a value not only in treating complex and unusual skull base pathology but also in providing a better and safer exposure to traditional pathology. However, a more widespread use of these complex skull base approaches is predicated on a clear understanding of the topographical areas of the skull base exposed and on how these complex approaches can improve the exposure afforded by more conventional surgical routes. PATIENTS AND METHODS: The study was performed on 43 surgical dissection with 20 embalmed cadevaric heads in which the cephalic vascular system had been injected with colored silicone material. RESULTS AND CONCLUSIONS: This paper provides an visual anatomical understanding of the areas of the skull base exposed by the approaches examined using the same cues(CT and MRI) that the surgeons use in selecting an approach when confronted with a real lesion and makes them to apply to the clinical situations properly and intimately for the optimal treatment. In addition, with the modular concept, the neurosurgeon may better understand how complex skull base approaches are derived and modified from, and improve the exposure of basic, well known conventional neurosurgical approaches as building block.
Brain Stem ; Head ; Humans ; Pathology ; Silicones ; Skull Base* ; Skull*

We have tracked the response of host and transplanted neural progenitors or stem cells to hypoxic-ischemic (HI) brain injury, and explored the therapeutic potential of neural stem cells (NSCs) injected into mice brains subjected to focal HI injury. Such cells may integrace appropriately into the degenerating central nervous system (CNS), and showed robust engraftment and foreign gene expression within the region of HI inury. They appeared to have migrated preferentially to the site of ischemia, experienced limited proliferation, and differentiated into neural cells lost to injury, trying to repopulate the damaged brain area. The transplantation of exogenous NSCs may, in fact, augment a natural self-repair process in which the damaged CNS "attempts" to mobilize its own pool of stem cells. Providing additional NSCs and trophic factors may optimize this response. Therefore, NSCs may provide a novel approach to reconstituting brains damaged by HI brain injury. Preliminary data in animal models of stroke lends support to these hypotheses.
Animal ; Brain/pathology ; Brain Diseases/therapy* ; Brain Diseases/pathology ; Brain Ischemia/therapy* ; Brain Ischemia/pathology ; Gene Therapy* ; Human ; Nerve Tissue/cytology* ; Stem Cells/transplantation* ; Tissue Therapy*

Auditory brainstem responses (ABR) have been used as a powerful and the most common objective tool to evaluate hearing sensitivity and to diagnose the types of hearing loss and neurological disorders, through the auditory peripheral pathway to a central level of the brainstem, since 1971. Although bone-conduction (BC) ABR could be an alternative to air-conduction (AC) ABR, as the former overcomes some limitations of the latter, the majority of clinicians rarely utilize it due to a lack of knowledge and no routine test administration. This review presents the weaknesses of AC ABR that apply to all clinical population, and discusses the development of BC ABR. The optimal placements of bone oscillators to obtain favorable clinical outcomes in infants, children, and adults, and the appropriate stimuli for BC ABR are examined. While providing absolute thresholds and latencies of BC ABR based on previous studies compared to AC ABR, this review includes clinical data of infants and young children with both normal hearing in terms of maturation, and with pathology such as congenital external auditory canal atresia. We recommend the future clinical application of BC ABR for candidacy as well as for patients with BC hearing implants.
Adult ; Brain Stem ; Child ; Ear Canal ; Evoked Potentials, Auditory, Brain Stem ; Hearing ; Hearing Loss ; Humans ; Infant ; Nervous System Diseases ; Pathology

Brainstem of rats were stabbed with a needle and pathological changes of neurons and axons in brainstem were observed at different time after injury with Nissl's body staining, silver staining and modified trichrome staining. It was found that, by silver staining, the axons showed irregular swelling and disconnection at 1-3 h, marked swelling of the severe end at 6 h, retraction ball at 15 h and remarkable retraction ball at 24 h. By modified trichrome staining, the space between myelin sheaths and axons was widened at 3-6 h, and tortuous myelin sheaths adhered incompletely on axons, or even peeled off at 15 h to 24 h. Perinuclear lysis of Nissl's bodies at 24 h after injury could be seen by Nissl body staining. The results indicated that, the pathological changes in injured brainstem could be observed with histochemical staining, which might be used for timing brainstem injuries.
Animals ; Axons/pathology* ; Brain Injuries/pathology* ; Brain Stem/injuries* ; Female ; Histocytochemistry ; Male ; Neurons/pathology* ; Rats ; Rats, Wistar ; Staining and Labeling

Animals ; Brain Neoplasms ; genetics ; pathology ; Cell Differentiation ; Cell Transformation, Neoplastic ; genetics ; Glioma ; genetics ; pathology ; Humans ; Neoplastic Stem Cells ; pathology ; Neural Stem Cells ; pathology ; Neuroglia ; pathology ; Neurons ; pathology

Animals ; Basilar Artery ; Brain Ischemia ; pathology ; Brain Stem ; blood supply ; Cats ; Medulla Oblongata ; blood supply

OBJECTIVE: To explore the distribution of inflammatory cells and positive expression of P-se- lectin glycoprotein ligand-1 (PSGL-1) in infant brainstem tissue from hand-foot-mouth disease related fatal brainstem encephalitis. METHODS: Twenty brainstem samples from infants suffered from brainstem en- cephalitis were collected as the experimental group. Ten brainstem samples from infants died of non- brain diseases and injuries were collected as the control group. The distribution of inflammatory cells and the expression of PSGL-1 in the two groups were examined by immunohistochemical method. The characteristics of the positive cells were observed. RESULTS: In brainstem tissue of the experimental group, there were sleeve infiltrations of inflammatory cells around the vessels and in the glial nodule. Microglia was the most and following was neutrophils around the vessels and in the glial nodule. There was a significant statistical difference among microglias, neutrophils and lymphocytes (P < 0.05). There was no sleeve infiltration in the control group. PSGL-1 protein was expressed widely in inflammatory cells in the experimental group, especially in the inflammatory cells around the vessels and in the glial nodule. But PSGL-1 positive staining could be observed significantly less in the control group comparing with the experimental group (P < 0.05). CONCLUSION Microglia is the main type of inflammatory cells involved in the progress of the fatal disease. Moreover, PSGL-1 could participate in the pathogenesis of hand-foot-mouth disease related fatal brainstem encephalitis.
Brain Stem/pathology* ; Encephalitis/pathology* ; Hand, Foot and Mouth Disease/pathology* ; Humans ; Infant ; Membrane Glycoproteins/metabolism* ; Microglia/pathology* ; Neutrophils/pathology*

Brain Stem/pathology* ; Death, Sudden/etiology* ; Fatal Outcome ; Humans ; Intracranial Hemorrhages/mortality* ; Leukemia/pathology*

Detailed characterizations of genomic alterations have not identified subtype-specific vulnerabilities in adult gliomas. Mapping gliomas into developmental programs may uncover new vulnerabilities that are not strictly related to genomic alterations. After identifying conserved gene modules co-expressed with EGFR or PDGFRA (EM or PM), we recently proposed an EM/PM classification scheme for adult gliomas in a histological subtype- and grade-independent manner. By using cohorts of bulk samples, paired primary and recurrent samples, multi-region samples from the same glioma, single-cell RNA-seq samples, and clinical samples, we here demonstrate the temporal and spatial stability of the EM and PM subtypes. The EM and PM subtypes, which progress in a subtype-specific mode, are robustly maintained in paired longitudinal samples. Elevated activities of cell proliferation, genomic instability and microenvironment, rather than subtype switching, mark recurrent gliomas. Within individual gliomas, the EM/PM subtype was preserved across regions and single cells. Malignant cells in the EM and PM gliomas were correlated to neural stem cell and oligodendrocyte progenitor cell compartment, respectively. Thus, while genetic makeup may change during progression and/or within different tumor areas, adult gliomas evolve within a neurodevelopmental framework of the EM and PM molecular subtypes. The dysregulated developmental pathways embedded in these molecular subtypes may contain subtype-specific vulnerabilities.
Humans ; Brain Neoplasms/pathology* ; Neoplasm Recurrence, Local/metabolism* ; Glioma/pathology* ; Neural Stem Cells/pathology* ; Oligodendrocyte Precursor Cells/pathology* ; Tumor Microenvironment

OBJECTIVE: To investigate the dynamic experiences of pathological changes in brain and the injured role of brainstem auditory evoked potential (BAEP) after closed Mild Traumatic Brain Injury (MTBI) in rat. METHODS: A closed diffuse brain injury model was successfully produced in rat by hit the parietal bone with a spring-droved steel stick. The auditory brainstem response evoked by click at 50Hz stimulating frequency were recorded at pre-trauma, 15 min and 1, 3, 6, 12 h and 1, 2, 4, 7, 10, 14, 21 d after brain injury. The pathological changes of brain were observed under light microscope and the brain edema was detected by wet weight/dry weight rations. RESULTS: The I-V, III-V of BAEP wave inter peak latency (IPL) in MTBI group increased immediately in 15 minutes after injury. The III, V wave peak latency (PL) and I-V, III-V wave IPL became longer than the pre-trauma level in 6, 12 h post-injury (P<0.05). The III, V wave PL and I - III, I - V, III - V wave IPL became longer than the pre-trauma level in 1, 2 d after injury (P < 0.001), the BAEP retuned to normal level in 14 d after brain injury. At 15 minutes after injury, the water content in brain increased and met its peak in 1 d, decreased gradually in 4 d, then decreased slowly and returned to normal level in 10 d after injury. CONCLUSION The regular changes of BAEP could be an objective tool for evaluating hearing dysfunction after closed mild diffuse traumatic brain injury.
Animals ; Auditory Perceptual Disorders/etiology* ; Brain/pathology* ; Brain Edema/pathology* ; Brain Injuries/physiopathology* ; Brain Stem/physiopathology* ; Disease Models, Animal ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley