Arachnoiditis

Anatomical and Physiological Changes in Aging

The human body is a complex connection of various systems, each affected by the internal and external environment. Each system relies on the other and changes in one can result in variations in all other organ systems. As humans age, their physical appearance changes, but the aging process also occurs below the skin. Each organ system is impacted by time, and an individual’s lifestyle can greatly impact his/her organ system. Various anatomical and physiological alterations that occur to the major organ systems due to aging and are relevant to an anesthesiologist are discussed below.

The Role of Age in Pediatric Tumors of the Central Nervous System

Pediatric tumors of the central nervous system (CNS) are the second most common type of solid childhood cancer. As such, they have a major effect on the rates of morbidity and mortality in children. CNS tumors originate from abnormal cells in the brain and/or spinal cord, which can be classified as either benign or malignant. They can be further subdivided into different categories based on several principal aspects, such as tumor location, histopathology, and developmental age. Among these various characteristics, age is one of the most consequential determinants for CNS tumors. Specific groups between 0 and 21 years of age, for instance, have radically divergent landscapes in terms of their tumor incidence and unique biology. Depending on the age of the child, key case features may differ like the clinical evaluation, medical diagnosis and prognosis, recommended therapy and treatment courses, anticipated responses and tolerability to treatment, and management of side effects. Effective teamwork is another crucial component for the successful management of pediatric CNS tumors. In patient-and-family-centered care, ensuring a detailed education of the children and their families, as well as their involvement in the decision-making process where appropriate, is imperative. To determine the best available options for the patient, multidisciplinary medical teams will often deliberate over all of the possible procedures. The holistic care provided by these interprofessional collaborations for this vulnerable population will depend on the age of the child, in addition to the level of patient and family participation. Evidence shows that support and counseling of the patient and their family during the entire treatment process can have a significant impact on outcomes. This chapter will review the essential diagnostic and prognostic considerations of childhood CNS tumors, with special emphasis placed on favorable therapies and treatments, including in-depth discussions around the multi-faceted responses to treatment and the management of its side effects. In particular, this content will highlight the critical role that age, and interdisciplinary healthcare teams play in comprehensive disease management.

Anatomy and Physiology of the Brain: Pathophysiology of Brain Tumor

The brain is an efficient processor of information. It is the most complex and sensitive organ in the body and is responsible for all functions of the body, including serving as the coordinating center for all sensations, mobility, emotions, and intellect. The magnitude of its myriad function is often realized usually when there is a disruption of the nervous system due to injury, disease, or inherited predispositions. Neuroscience is the field of study that endeavors to make sense of such diverse questions; at the same time, it points the way toward the effective treatment of dysfunctions. The two-way channel of information: findings from the laboratory leading towards stricter criteria for diagnosing brain disorders and more effective methods for treating them and in turn, the clinician's increasingly acute skills of diagnosis and observation that supply the research scientist with more precise data for study in the lab diligently expands the field of neuroscience. Tumors of the brain produce neurological manifestations through several mechanisms. Stronger hypotheses about the mechanism of a disease can point the way toward more effective treatments and new possibilities for a cure. In highly complex disorders of the brain, in which many factors genetic, environmental, epidemiological, even social and psychological—play a part, broadly based hypotheses are exceedingly useful. With the advancements in technology and a better understanding of brain anatomy and physiology, the quest to discover an efficient cure for life-threatening tumors of the brain is underway.

Subject Index

Abnormalities of the Central Nervous System

Treatment of Thoracic Meningioma with Spinal Canal Decompression under Spinal Endoscopy

Extramedullary benign tumors of the spine may cause spinal cord compression. Patients may present with motor weakness and sensory loss in the extremities causing gait abnormalities. Surgical treatment is indicated when symptoms are no longer manageable. In this chapter, the authors present an 87-year-old female's case as an illustrative example of how the spinal endoscopy platform can be safely and effectively deployed in the treatment of such lesions. The example patient suffered from spinal cord compression from a large meningioma at the T7 level. The tumor was successfully removed via an endoscopic working cannula. The patient's symptoms improved, and a nine-month follow-up MRI scan showed adequate and maintained spinal cord decompression. This case example demonstrates that spinal endoscopy may be applied to an increasing number of surgical indications beyond the scope of degenerative disease. Further clinical investigation will need to show this technology's limits when treating benign tumors of the spine.

Emerging Therapeutic Approaches for Neurodegenerative Diseases

The most common neurodegenerative diseases (ND) include Alzheimer’s disease (AD), Parkinson’s disease (PD) and Huntington’s disease (HD), as well as frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Protein misfolding and aggregation are the key hallmarks of these neurodegenerative diseases, which may lead to cell death, axonal regeneration failure, demyelination, and overall neuronal structural and functional deficits. Usually, ND is diagnosed at a very advanced stage and conventional therapies are directed at treating neurological symptoms but have no effect on disease progression. In general, several pathological processes contributes to misfolding proteins/protein aggregates and their postconsequences, including impairment of autophagy, microtubule destabilization, neuroinflammation, proteostasis, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum stress, calcium homeostasis, and neurogenesis impairment. Indeed, several signaling pathways critically linked with these pathological processes are now becoming attractive targets and investigated for their beneficial effects by restricting the progression of ND. In particular, certain signaling mechanisms and proteins found to show an integral involvement in the pathogenesis of ND and had shown promising results in preclinical and/or clinical contexts. For ex; novel autophagy stimulators, drugs acting on mTOR, NRF2, TLR, purinergic signaling; drugs acting on neuroinflammatory signaling pathways, Heat Shock Proteins (HSP), sestrins, sirtuins, some PDE-inhibitors, miRNA’s have gained a lot of attention in the therapy of ND and are included in the following discussion.

Endoscopic Treatment of Lumbar Facet Cysts

Cysts associated with degeneration of the lumbar facet joints are commonly encountered during routine lumbar endoscopy. They can be difficult to dissect and may heighten the risk of nerve root injury when they are fibrotically attached. Many of these cysts are extradural. Because of their highly inflammatory nature, they may be associated with radicular symptoms even without associated mechanical compression of the traversing or exiting nerve root of the symptomatic surgical level. These synovial cysts may be acutely painful. Their related symptoms may be difficult to distinguish from those caused by lumbar disc herniation or stenosis in the lateral spinal canal on clinical examination. The endoscopic spine surgeon is often forced to deal with them to complete the neural element decompression. What is less clear is what to do with patients with sizeable isolated facet joint based cysts without much other clinical pathology. The surgical indications and prognosticators of favorable clinical outcomes with endoscopic surgery are less well understood. Therefore, the authors performed a systematic analysis of their clinical series of patients they identified to have had synovial cysts either on preoperative advanced imaging studies or on those they found serendipitously during routine lumbar endoscopy. In total, 48 were identified in whom removal of the extradural cyst was performed during routine transforaminal and interlaminar endoscopy. The primary indication for surgery in these patients was painful foraminal and lateral recess stenosis. The patients were divided into 26 females and 22 males. The L4/5 level was the most frequent site of facet based cysts. It was found in 26 patients (72.2%). The second most common site was the L5/S1 level in 8 patients (22.2%), followed by two patients (5.6%) at the L3/4 level. A single patient had endoscopic decompression at the T9/10 level. Outcome analysis showed clinical improvements in all patients. According to the modified Macnab criteria, 19/48 (39.6%) patients had excellent outcomes. Good and fair results were achieved in 18/48 (37.5%) and 11/48 (22.9%) patients, respectively. The observed VAS leg pain score reductions were substantial and statistically significant (p < 0.000) from preoperative 8.06 ± 1.57 to postoperative 1.92 ± 1.49, and 1.77 ± 1.32 at final follow-up. One patient had a recurrent disc herniation, and another patient did not improve. Two patients underwent fusion during the follow-up period. Patients with Fair outcomes had a statistically significant association (p < 0.001) with facet instability as suggested by axial T2-weighted MRI imaging findings of thickened ligamentum flavum, facet joint hypertrophy, and a bright white fluid-filled joint gap of > 2 mm. Endoscopic resection of extradural spinal cysts that nearly exclusively stem from degenerated lumbar facet joints in skilled hands is feasible. Instability was one of the prognosticators of Fair Macnab outcomes.

Endoscopic Lumbar Discectomy – Anatomy, Indications and Techniques

Various endoscopic spinal surgery techniques to remove herniated discs in the lumbar spine have gained popularity. The “inside-out” and “outside-in” transforaminal techniques have been employed extensively, and their clinical indications have expanded with the advances in video-imaging and endoscopic optical and surgical equipment. In this chapter, the authors review some of the relevant anatomical considerations the endoscopic spine surgeon should consider when scheduling a patient for endoscopic spinal surgery. The authors also present their most up-to-date knowledge of technological advances and new endoscopic surgery techniques to provide the reader with a snapshot of modern advancements of the established transforaminal “inside-out” and “outside-in” and interlaminar methods. This chapter sets the anatomical stage for many of the following chapters in this volume 2 of the Bentham text series on Contemporary Endoscopic Spinal Surgery.

Neuropsychiatric Systemic Lupus Erythematosus (NP-SLE)

Neuropsychiatric systemic lupus erythematosus (NP-SLE) is one of the most

serious organ complications of SLE, affecting health, quality of life, and prognosis of

life in patients with SLE. Neurological symptoms are various. Among the pathological

conditions of SLE, those including neurologic syndromes of the central nervous

system, peripheral nervous system, and diffuse psychiatric and neuropsychiatric

syndrome are called NP-SLE in the American College of Rheumatology (ACR)

nomenclature. In NP-SLE, such a variety of pathophysiology should be considered

when selecting a treatment. In this article, we describe the neurological lesions of SLE

with illustrations.

Tuberculosis in Special Situations: Liver and Renal Disease, Pregnancy, Extrapulmonary Tuberculosis, Tuberculosis in Immunosuppressed Individuals other than HIV, Tuberculosis, and Diabetes

Although the underlying general principles of management of tuberculosis are the same for all cases, there are certain special situations in which the treatment regimen must be modified.

Uremia and post-renal transplant are both risk factors for tuberculosis due to the underlying immunodeficiency. Patients undergoing dialysis have a 10-25-fold higher risk of developing the disease than the general population.

Many antituberculosis drugs are hepatotoxic. If aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are increased more than three times the upper limit of normal in the presence of symptoms of hepatitis or >5 times the upper limit of normal, even if the patient is asymptomatic, all hepatotoxic drugs should be discontinued.

First-line drugs (HREZ) are safe during pregnancy, and regimen doses and duration are the same as in non-pregnant individuals. Pyridoxine (50 mg, vitamin B6) should be added to the regimen to prevent neuropathy in the mother and seizures in the fetus.

There is an increased risk of progression to active TB in subjects with latent infection TB and diabetes in comparison with the infected nondiabetic population. Also, outcomes for patients with TB and diabetes are worse than for TB patients without diabetes, and diabetes also increases the risk of drug-resistant TB.

Risk factors for extrapulmonary TB (EPTB) include advanced age, female gender, immunosuppression (including HIV) and chronic comorbidities. Symptoms and signs are usually non-specific, and except for miliary forms, the chest radiograph might be normal; therefore, the diagnosis of EPTB is frequently delayed with the consequent increase in morbidity and mortality.

Clinical Diagnosis of Tuberculosis

Symptoms and signs of active tuberculosis (TB) depend on its anatomical location. Pulmonary disease is the most common presentation of tuberculosis in the adult patient (more than 80% of the cases in the immunocompetent patient). Signs and symptoms can appear after just a few weeks from the primary infection, or many years later due to the reactivation of latent disease anywhere in the body.

Symptoms of pulmonary tuberculosis are nonspecific and may occur in many other pulmonary conditions; however, in high-burden regions, they remain a valuable tool for initial screening.

Signs and symptoms of extrapulmonary tuberculosis (EPTB) are protean, and chest xrays of the chest frequently do not show abnormalities. TB lymphadenitis is the most common form of EPTB, especially in children and young individuals.

Miliary tuberculosis is characterized by the presence of disseminated innumerable small nodules. It is secondary to the hematogenous spread of the bacilli throughout the body after the primary infection or the reactivation of a latent focus.

Although TB can involve any segment of the gastrointestinal tract, the ileocecal region is the most frequently affected. It is due to the ingestion of milk or milk products contaminated with M. bovis, the swallowing of secretions infected with M. tuberculosis, hematogenous dissemination of active TB disease, or from direct spread from contiguous organs.

Central nervous system tuberculosis is a consequence of hematogenous dissemination and the most severe form of the disease, with high morbimortality.

Subject Index

Typical Cases of Craniopharyngioma

In this section, we have provided clinical data from 15 cases of craniopharyngioma (CP) in which the details differ with respect to growth pattern. Emphasis has been placed on performance of the presurgical analysis and determination of the surgical aims, as well as potential surgical difficulties and the selection of a proper approach to achieve satisfactory exposure for tumor removal. Along with depictions of the tumors’ morphological features and schematic Fig. (1), we have described the surgical techniques and arachnoidal interfaces used for safe tumor removal while protecting vital neurovascular structures. Long-term follow up data have also been provided to demonstrate the patients’ prognoses. These cases have been subdivided into three types: infradiaphragmatic CP (Id-CP or “Q” type), suprasellar extra-ventricular CP with expansion in the subarachnoid cistern (SeV-CP or “S” type), and suprasellar subarachnoid CP with invagination to the third ventricular walls (SiV-CP or “T” type). Because of tumor growth along the longitudinal axis of the pituitary stalk (PS), each case might display different variations. We will illustrate this in special cases.

Clinical Manifestation and Management in Children

In this chapter, we focused on the description of the conception, clinical manifestation, surgical treatment and prognosis of pediatric craniopharyngiomas (CP), which were extremely different from the adult patients. As most of the tumors grew with development of the pituitary gland, stalk and hypothalamic structures in pediatric patients, surgery always caused severe endocrinological and hypothalamic dysfunction. And the postrugical irradiation was also restriced for younger children, with result as big problem for the quality of life in childhooh CP. In this chapter, we proposed two types of pediatric CP: infradiaphragmatic CP and intra-third ventricular floor CP. Those two types of CP presented totally variant characteristics with aspect in clinical manifestation, surgical strategy, recurrence, and prognosis, which will also be described and discussed in details.

Hypothalamus Status Evaluation

Hypothalamic obesity is a condition with extremely high morbidity. Mechanisms leading to the profoundly disturbed energy homeostasis are complex. Craniopharyngioma is one of the most common pathogenesis of hypothalamic obesity, which leads to the damage of hypothalamic nucleis due to the tumor compression or/and cytokines stimulation. The purpose of the present chapter is to summarize data on the prevalence of hypothalamic obesity, discuss the clinical features and review the diagnosis and treatment of these patients. Differences tumor growth patterns and locations should be considered when comparing outcomes and survival across different treatment paradigms in patients with CP. Further studies should be conducted to better understand the mechanisms of rapid weight gain and metabolic syndrome in patients with CP and could be used to enhance effective treatments and establish prevention strategy.

Hypopituitarism in Craniopharyngioma

Endocrine dysfunction is a common complication of craniopharyngiomas due to tumor location and the growth pattern. How to diagnose hypopituitarism and implement reasonable hormone replacement therapy, promote the recovery of endocrine function after operation is still a puzzle need to be solved urgently. The purpose of the present chapter is to summarize data on endocrinological evaluation in these patients, discuss clinical characters, and elaborate the growth features of childhood craniopharyngiomas. To understand the hypopituitarism patterns and its influencing factors of patients with craniopharyngioma has important effect on improving the prognosis and long-term quality of life.

Surgical Treatment of Recurrent Craniopharyngioma

Any neurosurgeon can’t avoid the tumor recurrence within the treatment of craniopharyngiomas. In this chapter, we focused on the description of the clinical manifestation, surgical strategy and prognosis of recurrent CP. Especially, the growth pattern of recurrent tumor as compared to the primary morphological features was emphasized and discussed. The influences of the first surgery or treatment strategy (pallilate or radical) were proposed based on the clinical casese analysis. As our opinion, the recurrent CP can be divided into 1) Intrasellar recurrence of Infradiaphgragmatic tumor, and 2) Suprasellar infundibulo-tuberal recurrence. Correspondingly, the different treatment strategies were also summarized. We thought for intrasellar recurrent, more radical surgery should be taken. While for the infundibulo-tuberal recurrence casued by palliative first surgery, more radical surgery was still the first choise. However, if radical total removal was selected in the first surgery, the repeated operation must be paid more attention.

Intraventricular Craniopharyngioma?

As we known, adamantinomatous craniopharyngioma (ACP) is thought to originate from residual Rathke’s pouch cells along the long axis from nasopharynx to infundibulum [1, 2]. However, the squamous papillary subtype of CP (SPCP) is believed to occur throught squamous metaplasia in the pars tuberalis [2, 3]. In consideration of these inferences, the neural parenchymal layer of third ventricular floor (3rd VF) should locate above the CP, separate both the tumor and third ventricular chamber. However, the first study conducted by Dubos et al. in 1953 extensively reported the tumors completely located inside the third ventricle cavity by autopsy or intraoperative finding [4-13]. Because of this topographical location, the theory of CP origin has been challenged and much more neurosurgeons are interested in pursuing the true morphological characteristics and diagnostic criteria of these tumors [9, 14]. In this chapter, we firstly reviewed the definition of the intraventricular CP in several publications. Then based on our histological and clinical study, the true morphology of intraventricular CP was proposed. The related approach selection and surgical skills was also depicted.

Suprasellar Infundibulo-Tuberal Craniopharyngioma (Type “T”)

Suprasellar infundibulo-tuberal craniopharyngiomas “Type T” were the most important and difficult tumors with all types of CP, which also the most common type. In this chapter, we focused on the clinical manifestation, growth pattern and prognosis of this type of CP. With summarizing our data and previous literatures review, the advantage of frontobasal interhemispheric approach was depicted emphasizedly. Moreover, by analysis of the relationship between tumor and the third ventricular walls, the defect and merit of transnasal and transcranial approach were discussed as well. Finally, the injury of hypothalamic structures and the psychological evaluation were depicted.

Subarachnoid Cisternal Craniopharyngioma (Type “S”)

In this chapter, we focus on a subgroup of craniopharyngioma (CP) in which the main tumor body is located exclusively in the suprasellar subarachnoid cisternal space around the pituitary stalk (PS) and there is no third ventricle involvement. Notably, the cases of CP reported in this chapter were not clearly defined in previous literature. The main reason for the confusion regarding this type of CP might be the lack of uniform criteria for evaluating the relationship between the tumor and third ventricle walls. The terminology “suprasellar extraventricular CP,” which is used in previous literature, might be another term for the cases described in this chapter; however, this term does not truly reflect the tumor origin and location.

Craniopharyngioma Classification: History and its Merit

The growth pattern of craniopharyngiomas (CP) is yet to be understood due to challenges arising from the diversity of morphological features that exist. This in turn has had implications on the development of safe surgical strategies for management of these lesions. In this chapter, we proposed a morphological classification of CP based on their tumor–membrane relationship, which will contribute to better understanding of CP morphology and prediction of the intraoperative classification. Moreover, based on our studies, the arachnoidal sleeve around the pituitary stalk (ASPS) was noted, and divided the pituitary stalk into four segments. Correspondingly, the growth of CPs was divided into four basic patterns—infradiaphragmatic (ID), extra-arachnoidal (EA), intra-arachnoidal (IA) and sub-arachnoidal (SA) growth. After analysis of 195 clinical cases of CP, we finally proposed the clinical classification “QST” classification, which detailed the relationship of the surrounding structures to CPs and purports to predict and identify the intraoperative anatomical stratification. It also attempts to help predict the growth patterns of these tumors. Finally, the surgical principle of approach selection for CP was discussed and proposed.

Anatomy Based on Transspenoidal Approaches for Surgery of Craniopharyngioma

As the sellar region location, the trans-nasal transsphenoidal corridor was thought to be the most effective approach to reach the surgical area. In recent decade, the endoscopic surgery developed extremely rapidly. As the result, more and more scholars tried to use transsphenoidal and it extended approach to dissect the craniopharyngioma (CP). In this chapter, we provided the basic anatomical details concerning the endonasal transsphenoid approach and its expanded application for surgical removal of CP. Moreover, several clinical cases and the morphological features of CP were analyzed. Base on the different classification of CP, the appropriate application of this approach was discussed.

Anatomy Based on Interhemispheric Approach for Surgery of Craniopharyngioma

In this chapter, based on interhemispheric approaches including the corridor through fronto-basal, anterior part of interhemispheric space and also through interfonix corridor, we illustrated the advantage of different approaches. And the related structures such as, pituitary gland, pituitary stalk, and hypothalamus were depicted under such surgical view. The other accessory structures, for example, optic pathway, sphenoid sinus and also the cavernous sinus were described as well. Moreover, the morphological features of craniopharyngioma were analyzed and then how to choose the most appropriate approaches was discussed.

Anatomy Based on Pterional Approach and its Extension Approach for Surgery of Craniopharyngioma

As the surrounding vital constructures, such as pituitary stalk, hypothalamus, third verntricule, et al, the surgery of craniopharyngioma (CP) is one of the most difficult in the field of neurosurgery. Better understanding the anatomy of sellar region, especially the related constructures to the possible origin site of CP are particularly important. In this chapter, we focus depicted the anatomy of sellar region based on the pterional approach, which is the most common surgical approach used in resection of CP. Within the description, we added the understandings about the surgical skills when removal the CP. Moreover, the morphology of tumor was analyzed and the reason of choosing pterional and its extension approach were also discussed.

Current Therapeutic Situation

Craniopharyngiomas are benign midline tumors that have a propensity for local recurrence and are ideally curable via total surgical resection. Many survivors suffer from behavioral, cognitive, endocrine, hypothalamic, and visual disturbances. Optimal management remains highly controversial. In this chapter, we reviewed the therapy strategies for Craniopharyngiomas including surgery, radiotherapy and chemotherapy. Complete resection is even more important in children, especially those younger than 3 years, because of the additional morbidity associated with radiotherapy during early childhood. The aim of radiotherapy is to achieve long-term disease control in patients lacking complete removal or with recurrent tumors. Systemic chemotherapy has rarely been reported in terms of craniopharyngioma management. Local intratumoral chemotherapy for craniopharyngioma was used to treat difficult, recurrent cystic tumors and has subsequently been employed as a strategy to avoid late-term effects of surgery or radiotherapy. The roles of all therapies should be balanced according to factors such as the patient’s age, the tumor size and location, and prior treatment.

The Pituitary Gland and Etiology of Craniopharyngioma

As histological benign tumor with malignant cellular characteristic, craniophayrngyioma (CP) caused big trouble not only for surgery but also for the postsurgical management. So, it is important to emphase the understanding of the pituitary gland and also it’s connected structures, such as pituitary stalk, hypothalamus, and so on. In this chapter, we described the anatomical and cytological constructors of pituitary gland. As with combined the etiology of CP, we depicted the embryonic development of gland and its accessory structures. On the other hand, several hypotheses about the origin of CP were also analysed and described.

History and Epidemiology of Craniopharyngioma

In this chapter, we firstly briefed reviewed the history and the terminology of craniopharyngioma (CP). Then with summarizing our own data based on 10 top hospitals in China and previous publications, we focused on description of the Epidemiology of craniopharyngioma (CP). And correspondingly, clinical manifestation of CP patients was depicted as well.

Syndromes with Orofacial Clefts

Orofacial clefts are among the commonest malformations affecting mankind; even though most cases of orofacial clefts are non-syndromic, they may also manifest concomitantly with a wide array of syndromes. These syndromes with orofacial clefts often also cause diverse tooth abnormalities; knowledge on these peculiarities is fundamental for professionals to allow proper dental care for affected individuals.

Free-living Amoebae

Acanthamoeba Species is the most common free living amoeba present in environment. It is isolated from soil, water, contact lens solutions, transplant units and various other hospital environment. There are many species of Acanthamoeba such as A.astronyxis, A.castellani, A.culbertsoni, A.hatchetti, A.keratitis etc. which are known to cause opportunistic infection in both immunocompetent as well as immunocompromised host. Transmission mainly occurs through direct contact. There are two described morphological forms; a trophozoite form and a cyst form. The trophozoites have characteristics pointed thorn like acanthapodias, containing one nucleus with central dense large nucleolus. The cytoplasm measures between 15-50μm, granular and contains various organelles. Clinically patients usually presents with granulomatous amoebic encephalitis (GAE) which is characterized by focal neurological deficit, headache, visual disturbances, seizures and behavioral abnormalities which develops over months to years. Laboratory diagnosis of Acanthamoeba spp. is done by examining CSF which generally shows predominant lymphocytes, elevated proteins and low glucose levels. Histopathological samples of the brain generally reveals cerebral edema, multiple necrotic and hemorrhage lesions. Acanthamoeba can easily be cultivated on non-nutrient agar with overlay of Escherichia coli or Entrobacter spp. Amoeba feeds on bacteria’s and confluent growth is seen in 4-5 days of culturing. The combination therapy is advisable in proven cases of Acanthamoeba infection. Combining Amphotericin B plus Trimethoprim- Sulphamethoxazole plus rifampicin has successfully used in few cases.

Naegleria Fowleri: The organism was first reported in Australia in 1965. It is an environmental ameboflagellate parasite found in variety of water bodies such as ponds, swimming pools; aquarium etc. prefers temperature of 30-45ºC. There are three stages seen in Naegleria life cycle: the infective trophozoites, transient flagellated and the resistant cystic stage. The portal of entity of trophozoites is via olfactory neuroepithelial cell lining covering the cribriform plate to reach olfactory bulb. Demyelination and myelinoclasis are observed in gray matter due to vascular blockage. These pathological changes are attributed to release of phospholipolytic enzymes which causes breaks in the lipid membrane of neuronal cells. Clinically, patients of primary amoebic meningoencephalitis (PAM) usually presented with high grade fever,headache, photophobia and features of raised intracranial pressure. Laboratory diagnosis is done using peripheral smear, CSF examination, culture, histopathological examination and imaging modalities. Hematological findings are leukocytosis with predominant neutrophils. The CSF shows low glucose and high protein levels. Centrifugation of fresh CSF sample up to 500 RPM may reveal motile trophozoites. Morphologically, the size of trophozoites ranges between 12-25μm, with a single nucleus and centrally placed nucleolus in the absence of peripheral chromatin. Liquid culture media such as such as Nelson’s medium containing ox liver digest and glucose are used with serum for growing amoebae. Mammalian cell lines can be employed to demonstrate cytopathic effect. Multiplex PCR detects free living amoeba within 6 hours but routine use in diagnostic laboratory is limited due to rarity of finding these organisms and having high cost of PCR. Brain imaging is easy to perform but restricted by nonspecific findings such as cerebral edema. Specifically, infraction involving frontal, orbital and cerebellum area can be observed in few cases of PAM. There is no optimal treatment regime for Naegleria fowleri. Literature suggests combination therapy works best with amphotericin, rifampicin and azithromycin.

Balamuthia Mandrillaris: Over 200 cases were reported from South America and United States. The true prevalence of disease is unknown in south East Asia. Organism is commonly isolated from soil contact with activities related to soil such as gardening, agriculture pose risk of acquiring the organism. It was first isolated in 1986 from baboon brain that died of meningoencephalitis. The portal of entry of the organism is via cutaneous lesions, nasal mucosa and then subsequent spread to brain. CNS lesions mimic acanthamoeba encephalitis and have chronic slowly progressive course over many years. The life cycle of Balamuthia involves two stages: trophozoites and the cyst. The morphologically variable trophozoites are 12- 60 microns in size containing single nucleus with large centrally placed nucleolus. Cysts are spherical in shape measuring 12-30μm and contain a single nucleus with double wall having outer ectocyst, middle fibrillar layer and inner amorphous endocyst.The trophozoites, cysts and inflammatory cells are observed in perivascular regions of the infected tissue. In CSF, elevated protiens, reduced glucose are common findings. Balamuthia spp. can be grown in tissue cultures such as Monkey Kidney cell lines, Human Lung fibroblast and Human Brain Microvascular Endothelial cell lines. ELISA test is very specific to detect high antibodies titers. The antibodies do not cross react with other free living amoebae. PCR is also highly specific and sensitive test in which primers are developed against mitochondrial rRNA genes. Recently, real time PCR are developed targeting RNAase P gene of B.mandrillaris.

Sappinia Species: Two species of Sappinia are well-known cause of CNS infections in humans, Sappinia diplodea and Sappinia pedata. S.diploidea was first isolated from lizard faeces. As this parasite is found in animal faeces, persons handing livestock are at higher risk. Only one known case of Sappinia encephalitis infection reported in literature. The diagnosis was confirmed on histopathological sample, which showed necrotizing haemorrhagic inflammation of infected tissue, containing trophozoites. The trophozoite of Sappinia is characterized by two opposing nucleus with central flattening. Diagnosis can also be done by amplifying rDNA of both Sappinia diploidea and Sappinia pedata using SSU primers. The real time PCR can also be used based on 18rRNA gene sequences. Sappinia spp. is cultivated on non- nutrient agar with overlay of Enterobacter or Escherichia coli. Vahlkamphia spp. and Paravahlkamfia francinae are other emerging free living amoebas that were first isolated from CSF of young patient who presented with typical symptoms of primary amoebic meningoencephalitis.

Terson Syndrome

Neurosurgery in Brain Ischemic Stroke

Ischemic strokes caused by the complete occlusion of an intracranial artery are associated with poor outcomes overall, and high mortality rates. To improve the survival and the outcome otherwise not afforded by the available medical and interventional therapies a neurosurgical approach must be considered. In selected patients a microsurgical embolectomy and a decompressive craniectomy are effective therapies with which to treat occlusions of the middle cerebral artery or other territories when thrombolysis or an interventional endovascular embolectomy does not restore the vascular flow. A bypass procedure that employs a superficial temporal artery-to-middle cerebral artery (STA-to-MCA) surgical anastomosis can be performed to improve the blood flow in a deficient artery chronic angiopathic disorder.

Surgical Treatment of Spinal Dural Arteriovenous Fistulas

Thoracolumbar Extradural Arachnoid Cyst Surgery

Minimally Invasive Thoracic Intradural Extramedullary Tumor Resection

Spinal Meningioma Resection

Spinal Schwannoma Resection

Spinal Hemangioblastoma Resection

Intramedullary Tumor Resection

Endoscopic Chiari Decompression

Occipitocervical Chiari Decompression

Subject Index

Non-Parasitic Cystic Diseases of the Liver

• Non-parasitic cystic lesions of the liver are common (up to 5-20% of the population), mainly simple cysts, and increasing in incidence with age. Most of them are asymptomatic and diagnosed incidentally at abdominal surgery or radiological studies for unrelated disease.

• Symptomatic simple cysts and polycystic liver disease are frequently treated by deroofing or partial hepatectomy (associated or not with deroofing of residual cysts). In selected cases, liver transplantation can represent the only definitive treatment, especially if portal hypertension or cirrhosis is present. Percutaneous aspiration, with or without sclerotherapy, can be useful to determine if symptoms are related to the cysts to be treated, or it can be used rarely as a definitive treatment (when associated with sclerotherapy).

• Neoplastic cysts include benign biliary cystadenoma and cystadenocarcinoma. Cystadenoma originates from intrahepatic bile ducts and may undergo malignant transformation to biliary cystadenocarcinoma, and therefore require more aggressive management.

• Cystic biliary dilatation of Caroli’s disease is frequently associated with complications, especially hepatolithiasis and recurrent cholangitis. Liver resection is the treatment of choice for unilobar disease, and it can be associated with contra-lateral clearance of stones in bilobar disease. Treatment of diffuse disease is challenging, sometimes requiring liver transplantation as a definitive treatment.

• Other rare cystic lesions of the liver include cystic metastases or primary tumors and post-traumatic cysts among others. They should have individualized treatment.

Applied Macro-, Micro-, and Sonoanatomy of the Neuraxium

The spinal column has 33 vertebrae: seven cervical, twelve thoracic, five lumbar, five sacral (fused), and four coccygeal. There are four curves in the spinal column: the cervical and lumbar curve convex anteriorly, whereas the thoracic and sacral curves convex posteriorly. The macro-, microanatomy, and sonoanatomy (static) of neuraxium, its content and relationships to other structures are discussed in this chapter. Special attention is given to the ligaments of the spine, and the ligamentum flavum in particular, paying special attention to the shapes that the spinal canal takes in certain regions, and the structure and consistency of the ligamentum flavum. Two further questions are specifically addressed in detail in this chapter. The first questions are why an epidural block is “segmental” and does not, like subarachnoid anesthesia, block the entire spinal cord distal to the site of injection. The second question answered in this chapter is why elderly people are less prone than their younger counterparts to developing postdural puncture headache following accidental dural puncture during attempted epidural block. Both of these questions are comprehensively addressed in this chapter on microanatomical grounds.

Applied Macro- and Sonoanatomy of the Lumbar Paravertebral Space

The positioning of the lumbar plexus within the psoas muscle is somewhat controversial. Winnie, for example, described the plexus as lying between the psoas and quadratus lumborum muscles. From this description, “psoas compartment block” was termed for the lumbar plexus block. Other names for the same thing are “lumbar plexus block”, “lumbar paravertebral block”, “quadratus lumborum block” and “fascia iliaca block” to name a few. Most authors described the plexus and its nerve branches within the psoas muscle between its anterior and posterior masses. The ventral rami of the first three and the major part of the fourth lumbar spinal roots (L2, L3, and L4) form the lumbar plexus. A contribution from the 1st lumbar nerve (L1) is common. As soon as the ventral rami of these spinal nerve roots exit the intervertebral foramina, they become embedded in the psoas muscle, anterior to the transverse processes. At the L4 to L5 level, however, the lumbar plexus branches are still medial and close to the transverse processes. The distance of the lumbar plexus to the skin varies with body habitus and gender. Capdevila and his colleagues described the distances as varying from 57 to 93 mm in women and from 61 to 101 mm in men.

The macro-, microanatomy, and sonoanatomy (static) of the lumbar plexus, its nerve roots, and relationships to other structures are discussed in this chapter.

Applied Macro-, Micro-, and Sonoanatomy of the Thoracic Paravertebral Space

The thoracic paravertebral space (TPVS) is a wedge-shaped space of which the anterior boundary is the parietal pleura of the lung. The superior costotransverse ligament (SCTL) and the internal intercostal membrane (IIM) form the posterior boundary, while the posterolateral aspect of the vertebra, the intervertebral disc, and the intervertebral foramen form the medial border. Superior and inferior the boundaries are the heads and necks of the ribs. The TPVS contains spinal nerve roots, the posterior rami of the thoracic nerves, the anterior rami, which comprises the intercostal nerves, the gray and white rami communicantes to the sympathetic chain and the sympathetic chain itself, the spinal rami from the aorta, and an intervertebral veins that form a vascular plexus. The TPVS communicates superiorly and inferiorly with the adjacent TPVS above and below, medially with the spinal epidural space, and laterally with the intercostal space. The macro- and microanatomy and sonoanatomy (static and dynamic) of these spaces and its nerve roots and relationships to other structures are discussed in this chapter.

The Microanatomy of the Brachial Plexus and Peripheral Nerves

The aims of this chapter are to explain and present the older and new concepts and understanding around the microanatomy of nerve roots, trunks, and peripheral nerves. More recent work over the past 3 or 4 years looked at nerves with high-definition ultrasound and electron microscopy and illustrated that the paraneural or circumneural sheath is what neurosurgeons for years have been calling the “gliding apparatus” of the nerve. The space just deep to this layer is the subcircumneural (subparaneural) space, which should most probably be the target space for successful and safe single-injection block and catheter placement for continuous nerve block. The different microanatomical features of spinal roots, plexus trunks, and peripheral nerves are discussed and compared, as well as the microanatomical explanation of the different sonographical appearance of these three types of nerves.

Index

Control of Breathing

The automatic rhythm of breathing is generated by specialized neurons of the medulla oblongata: the Dorsal Respiratory Group (DRG) and the Ventral Respiratory Group (VRG). The DRG represents the “inspiratory center” whereas the VRG is mostly expiratory; the caudal portion of VRG, together with the Bötzinger complex in its vicinity, constitutes the “expiratory center”. Normally, inspiration occurs actively via signals from the inspiratory neurons to the inspiratory muscles (mainly the diaphragm). Expiration occurs passively owing to the elastic recoil of the lungs. Expiratory neurons are activated only under certain conditions such as increased physical activity. The Pontine Respiratory Group (PRG, upper pons) represents the “pneumotaxic center”, which acts as an “off” switch controlling the point at which inspiration is terminated and therefore determining the depth and frequency of breathing. Ventilation is also subject to direct voluntary control by the cerebral cortex, as it occurs during such maneuvers as breath holding. The activity of the respiratory centers is constantly modified in response to feedback from a variety of sensors in the periphery as well as within the brain. Both the long term and the moment-to-moment regulation of alveolar ventilation are primarily the task of chemosensitive cells in the ventrolateral aspect of the medulla (central chemoreceptors) and in the carotid and aortic bodies (the peripheral chemoreceptors). These chemical sensors monitor the levels of CO₂, O₂, and H⁺ in arterial blood.

The Genus Pleurotus (Fr.) P. Kumm. (Pleurotaceae) in Europe

The genus Pleurotus comprises ca. 30 species and subspecific taxa of edible mushrooms with a world-wide distribution. Most of them are cultivated on a large range of agricultural and forestry residues and by-products providing a relatively cheap food of high dietetic value through rather simple solid-state fermentation processes. In addition, Pleurotus biomass demonstrates significant medicinal effects and its bioactive compounds (mainly polysaccharides) possess antibiotic, antitumor, hypocholesterolemic and immunomodulation properties. One of the most important aspects related with the exploitation of Pleurotus fungi is that they are powerful lignin decomposers and hence they are used as potent biodegraders of numerous organic pollutants, xenobiotics and industrial wastes. However, all such biotechnological applications are tightly linked with the isolation, identification, evaluation and improvement of the respective genetic resources. Assessments of Pleurotus diversity in Europe in conjunction with biochemical, molecular and compatibility studies revealed the existence of eight species, i.e. P. calyptratus, P. cornucopiae, P. dryinus, P. eryngii, P. fuscosquamulosus, P. nebrodensis, P. ostreatus and P. pulmonarius, which are described in detail (anatomy, ecology and distribution). Furthermore, P. abieticola and P. opuntiae are two additional species reported to occur in Europe, albeit infrequent to very rare; the former was isolated from east Russia whereas the latter in Mediterranean Europe. A synthesis of available information on Pleurotus systematics is also presented and discussed.

Protection Mechanisms Against Aβ42 Aggregation

It is widely accepted that Aβ42 aggregation is a central event in the pathogenesis of Alzheimer's disease. Aβ42 oligomers and fibrils cause the breakdown of neural circuits, neuronal death and eventually dementia. There are a number of physiological molecules that can protect Aβ42 from aggregation. Promoting such protective molecules and mechanisms against Aβ42 aggregation may be a novel direction in AD drug discovery. One of the most striking protective molecules is none other than Aβ40, which inhibits Aβ42 aggregation in a specific and dosage dependent manner. Aβ40 is a critical, built-in mechanism against Aβ42 aggregation. A number of other molecules and mechanisms also inhibit Aβ42 aggregation, such as heat shock proteins, L-PGDS, heme and methionine oxidation. The relevance of these protective mechanisms to AD pathogenesis and intervention is discussed.