6 Clinical Trials for Various Conditions
The purpose of the study is to determine if the ShuntCheck test can correctly identify flow or no flow in a ventriculoperitoneal shunt in patients with pseudotumor cerebri.
This study will examine whether the tendency to have thrombosis, or the formation of blood clots inside blood vessels, has a role in the development of pseudotumor cerebri (PTC). PTC causes symptoms and signs of isolated elevated blood pressure in the cranium, or covering of the brain. The disorder can lead to significant, negative effects on the visual system. Increased pressure of the cerebrospinal fluid, that is, fluid around the brain, is a factor, but the cause of the disorder is not clear. There has been documentation of clustering of PTC within families. It suggests that potential genetic polymorphisms-abilities to take on different forms-may become evident after exposure to conditions known to trigger PTC. Thrombosis comes about by interactions between genetic and environmental or acquired factors, or both, resulting in a blood clot at a specific time and location. Because the disease occurs in episodes, the interaction of the genetic and nongenetic risk factors is important. Cystinosis is a recessive disorder caused by deposits of cystine within the lysosomes of cells-that is, sac-like cell parts that contain various enzymes. Involvement of the kidneys remains the primary characteristic, eventually leading to renal failure. Of all of the risk factors that make it easier for blood clotting, a high level of a substance called homocysteine is of particular interest. Too much homocysteine in blood plasma is a common finding in patients with kidney failure, and it has been recently identified as an independent risk factor for diseases of the blood vessels. Participants of all ages who meet the Dandy criteria for PTC may be eligible for this study. Pregnant women will be excluded. There will also be a control group of nephropathic cystinosis patients who do not have PTC. Participants will be asked to undergo the following tests and procedures: * Medical history. * Physical examination, to evaluate the eye and nervous systems. * Collection of blood for DNA and other tests. * Collection of cerebrospinal fluid, through a procedure called lumbar puncture or spinal tap. The evaluation of patients will generally last 3 to 4 days. For the collection of cerebrospinal fluid, the patient's skin on the back will be numbed with a local anesthetic. A special needle will be inserted into the back, and a small amount of the fluid will be drawn through the needle. There will be pain for a minute, although there can be a headache lasting 24 hours. Also, there may be bruising, local pain, bleeding, or infection where the needle enters. Patients may also have a magnetic resonance imaging scan of their head. During the MRI scan, patients will lie still on a table that slides in and out of a metal cylinder surrounded by a strong magnetic field. Patients will be able to communicate with the MRI staff at all times and may ask to be moved out of the machine at any time.
Pseudotumor cerebri, also called idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure, headache, and if severe, vision loss. IIH is difficult to treat. Medical management may not adequately resolve the symptoms, and surgical management (primarily through cerebrospinal fluid \[CSF\] shunting) has a high failure rate. Recently, a relationship between IIH and stenosis of the dural venous sinuses (the veins that drain blood from the brain) has been reported. In patients with IIH in whom there is stenosis of one or more dural venous sinuses, placing a stent in the venous sinus may improve patients' objective symptoms (such as visual loss and papilledema) and subjective symptoms (such as headache). This study will determine whether dural venous sinus stenting is as effective as CSF shunting (considered the standard surgical treatment) in treating IIH patients who have moderate vision loss and stenosis of the dural venous sinuses.
This study will compare the VerTouch device to the conventional palpation technique for performing diagnostic and therapeutic neuraxial procedures.
This research is being done to determine the accuracy of two noninvasive methods of measuring the pressure of the cerebrospinal fluid (CSF), also known as intracranial pressure or ICP.
Papilledema is defined as swelling of the optic nerves often due to increased intracranial pressure. When present, it often indicates life-threatening lesions of the brain such as tumors, abscesses, meningitis, encephalitis, venous sinus obstruction or intracranial hemorrhage. A similar clinical picture can also be caused by other conditions such as malignant hypertension, diabetic papillopathy and uremia. When the intracranial pressure is elevated in the absence of any known cause then it is called Idiopathic Intracranial Hypertension (IIH). Untreated papilledema can cause progressive optic nerve damage and blindness. Patients with chronic kidney disease have a number of co-morbidities and thus are at an increased risk for developing papilledema. Although clinicians have observed that patients with kidney diseases have increased incidence of papilledema (unpublished data by Corbett et al), there have been no studies on this subject to date. We believe that a higher incidence of papilledema is found in patients with kidney diseases and this study could provide evidence to suggest routine ophthalmic screening in this patient group. Hypothesis: The prevalence of optic disc swelling is increased in patients with chronic kidney disease. Purpose: To establish the prevalence of disc edema in patients with chronic kidney disease.