Semester 2 Neuro, Week 2 - Fundamentals, Meninges, Ventricles And Csf

Based on the findings of increased proteins, decreased glucose levels, increased WBCs with increased polymorphs in the cerebrospinal fluid (CSF) obtained from the lumbar puncture, the most likely diagnosis for this patient is bacterial meningitis. These CSF findings are consistent with the inflammatory response seen in bacterial meningitis, where there is an increase in protein levels, a decrease in glucose levels due to bacterial consumption, and an increase in white blood cells, particularly polymorphonuclear cells. Viral meningitis would typically show a lymphocytic predominance in the CSF. Subarachnoid hemorrhage and intracerebral hemorrhage would have different CSF findings and would not present with the same symptoms as described in the question.

If the Foramen of Megendie is obstructed, it would result in non-communicating hydrocephalus. The Foramen of Megendie is a small opening in the brain that allows cerebrospinal fluid (CSF) to flow from the ventricles to the subarachnoid space. When this opening is blocked, CSF cannot properly drain, leading to an accumulation of fluid within the ventricles. This causes an increase in intracranial pressure and can result in symptoms such as headaches, nausea, and cognitive impairment.

Arachnoid villi are small finger-like projections of the arachnoid membrane that extend into the venous sinuses of the brain. These villi act as one-way valves, allowing cerebrospinal fluid (CSF) to be absorbed from the subarachnoid space into the venous system. This process helps to maintain the balance of CSF production and absorption, preventing the buildup of excess fluid in the brain. Therefore, arachnoid villi are responsible for returning CSF directly to the venous system.

An epidural hematoma is a collection of blood that forms between the skull and the dura mater, which is the outermost layer of the meninges. This type of hematoma occurs when there is a tear in the middle meningeal artery or one of its branches, resulting in bleeding into the potential space between the skull and the dura. It is important to recognize and treat epidural hematomas promptly, as they can cause increased intracranial pressure and potentially life-threatening complications.

The foramen of Magendie is the correct answer because it is the main opening through which cerebrospinal fluid (CSF) flows from the fourth ventricle into the cisterna magna. This opening is located in the midline of the fourth ventricle and allows CSF to exit the ventricular system and circulate around the brain and spinal cord. The other options mentioned are not involved in the flow of CSF from the fourth ventricle to the cisterna magna.

In the case of a subarachnoid hemorrhage, blood is leaked into the space between the brain and the thin tissues that cover it, known as the subarachnoid space. This leakage of blood can be detected through a lumbar puncture, which involves taking a sample of cerebrospinal fluid (CSF) from the lower back. In a subarachnoid hemorrhage, the CSF sample would show increased protein levels due to the presence of blood, normal glucose levels as glucose is not typically affected by bleeding, and the presence of red blood cells. Therefore, the answer choice "Increased protein, normal glucose and red blood cells" is the most likely to be seen in this scenario.

The correct answer is Foramen of Megendie. The question describes a condition where there is obstruction of the medial foramen draining the fourth ventricle. The foramen of Megendie, also known as the median aperture, is one of the three openings through which cerebrospinal fluid (CSF) flows out of the fourth ventricle and into the subarachnoid space. When this foramen is obstructed, it can lead to an accumulation of CSF in the ventricles, causing hydrocephalus.

The CSF flows from the 4th ventricle to the cistern magna via the median aperture. This is the correct answer because the question states that the woman has a tumor in her 4th ventricle, which suggests that there may be obstruction or blockage of CSF flow in this area. The CSF normally flows from the lateral ventricles to the 3rd ventricle via the cerebral aqueduct, then from the 3rd ventricle to the 4th ventricle via the foramen of Monroe. From the 4th ventricle, it then flows to the cistern magna via the median aperture. The other options mentioned in the question are not characteristic of CSF flow under normal conditions.

The correct answer is "More than one above." This is because neurons whose cell bodies are located in dorsal root ganglia have both peripheral and central nervous system components, and they are pseudo-unipolar neurons. They are not cranial nerve cells, as they are part of the spinal nerves. They are also not derived from the neural tube, as they originate from neural crest cells.

Newborns with anencephaly may still display reflex activity. Anencephaly is a neural tube defect that occurs when the upper part of the neural tube fails to close during fetal development. This results in the absence of a major portion of the brain, skull, and scalp. Despite the severe brain abnormalities, some reflex activities such as grasping, sucking, and swallowing may still be observed in newborns with anencephaly.

A tumor in the cerebral aqueduct can cause obstruction of cerebrospinal fluid (CSF) flow, leading to non-communicating hydrocephalus. In this condition, CSF accumulates within the ventricles of the brain, causing an increase in intracranial pressure. This increased pressure can cause a shift of the cranial contents in an inferior and medial direction, as the brain is compressed against the skull. This displacement can be seen on imaging studies such as CT or MRI. The other options are not typically associated with non-communicating hydrocephalus.