By L. Iomar. MacMurray College. 2018.
Traditionally purchase 100 mg januvia fast delivery, this classiﬁca- tion was based on whether dye injected into the lateral ventricles could be detected in CSF extracted from a subsequent lumbar puncture januvia 100mg lowest price. Currently, the term ‘‘noncom- municating hydrocephalus’’ refers to lesions that obstruct the ventricular system, either at the cerebral aqueduct of sylvius or basal foramina (i. The term ‘‘communicating hydrocephalus’’ refers to lesions that obstruct at the level of the subarachnoid space and arachnoid villi. Lateral Ventricle Choroid plexus tumors are rare in the pediatric population, with an incidence ran- ging from 1. Most choroid plexus tumors are choroid plexus papillomas, which usually present within the ﬁrst 3 years of life. The CSF production rates three to four times the normal rate have been documented in children with choroid plexus papillomas. Removal of the papilloma resolves the 25 26 Avellino Table 1 Causes of Hydrocephalus Based on Site of Obstruction Lateral ventricle Choroid plexus tumor Intraventricular region glioma Foramen of Monro Congenital atresia Iatrogenic functional stenosis Stenotic gliosis secondary to intraventricular hemorrhage or ventriculitis Third ventricle Colloid cyst Ependymal cyst Arachnoid cyst Neoplasms such as craniopharngioma, chiasmal-hypothalamic astrocytoma, or glioma Cerebral aqueduct Congenital aqueduct malformation Arteriovenous malformation Congenital aqueduct stenosis Neoplasms such as pineal region germinoma or periaqueductal glioma Fourth ventricle Dandy–Walker cyst Neoplasms such as medulloblastoma, ependymoma, astrocytoma, or brainstem glioma Basal foramina occlusion secondary to subarachnoid hemorrhage or meningitis Chiari malformations hydrocephalus in approximately two-thirds of cases. The remaining third probably suffer from obstruction of the aqueduct and=or basal meninges and require a ventricular shunt presumably secondary to preoperative microhemorrhages or postoperative scarring of the arachnoid villae. Foramen of Monro Occlusion of one foramen of Monro can occur secondary to a congenital membrane, atresia, or gliosis after intraventricular hemorrhage (IVH) or ventriculitis. The result- ing unilateral ventriculomegaly is often occult until early childhood, and may enlarge the ipsilateral hemicalvarium. An iatrogenic functional stenosis of the foramen of Monro can develop in chil- dren with spina biﬁda whose hydrocephalus has been treated with a ventricular shunt. The contralateral nonshunted ventricle occasionally expands secondary to deformity of the foramen of Monro. If symptomatic, the patient can be treated with a shunt system having two ventricular catheters, each draining a separate lateral ven- tricle or an endoscopic fenestration of the septum pellucidum with one ventricular catheter draining both ventricles. Third Ventricle Cysts and neoplasms within the third ventricle commonly cause hydrocephalus. Col- loid cysts are uncommon neoplasms that present superiorly and anteriorly within the third ventricle, and usually obstruct both foramina of Monro. Considered to Hydrocephalus 27 be congenital lesions, they can become symptomatic at any age.
This is the philosophy or the general princi- ple which will guide your research januvia 100mg online. It is the overall ap- proach to studying your topic and includes issues you need to think about such as the constraints januvia 100mg free shipping, dilemmas and ethical choices within your research. Now that you have read Chapter 1, some of these issues will be fresh in your mind. Your research methodology is diﬀerent to your research methods – these are the tools you use to gather data, such as questionnaires or interviews, and these will be discussed in Chapter 3. UNDERSTANDING THE DIFFERENCE BETWEEN QUALITATIVE AND QUANTITATIVE RESEARCH When you start to think about your research methodol- ogy, you need to think about the diﬀerences between qua- litative and quantitative research. Qualitative research explores attitudes, behaviour and ex- periences through such methods as interviews or focus groups. As it is attitudes, behaviour and experiences 14 HOW TO DECIDE UPON A METHODOLOGY / 15 which are important, fewer people take part in the re- search, but the contact with these people tends to last a lot longer. Under the umbrella of qualitative research there are many diﬀerent methodologies. If you wish to pursue any of these in more depth, useful re- ferences are included at the end of this chapter. Quantitative research generates statistics through the use of large-scale survey research, using methods such as questionnaires or structured interviews. If a market re- searcher has stopped you on the streets, or you have ﬁlled in a questionnaire which has arrived through the post, this falls under the umbrella of quantitative research. This type of research reaches many more people, but the con- tact with those people is much quicker than it is in quali- tative research. Qualitative versus quantitative inquiry Over the years there has been a large amount of complex discussion and argument surrounding the topic of re- search methodology and the theory of how inquiry should proceed. Much of this debate has centred on the issue of qualitative versus quantitative inquiry – which might be the best and which is more ‘scientiﬁc’. Diﬀerent meth- odologies become popular at diﬀerent social, political, historical and cultural times in our development, and, in my opinion, all methodologies have their speciﬁc strengths and weaknesses. At the end of this chap- ter references are given if you are interested in following up any of these issues.