ANA 303 Ventricular System Flashcards

Question

Describe arachnoid granulations

Answer 1

Aracnoid granulations are like the workers at the end of the CSF production line, ensuring everything gets cleaned up and recycled efficiently

Answer 2

Hydrocephalus is a condition in which there is an abnormal accumulation of CSF in the brain due to a disturbance of flow or absorption, leading to an increase in the volume occupied by CSF in the CNS, causing increased intracranial pressure. Hydrocephalus is characterised by head enlargement in infants. The narrow space of the 3rd V. easily gets blocked by tumours leading to increased intracranial pressure in adults and hydrocephalus in children. It can be due to to: Excess production Impaird reabsorption into bloodstream Blockage in the ventricular system that causes CSF to accumulate

Answer 3

* Headache * Blurred or double vision. * Eye movements that are not usual. * Enlargement of a toddler's head. * Sleepiness or sluggishness. * Nausea or vomiting. * Trouble with balance. * Poor coordination.

Answer 4

Communicating Non-communicating/ obstructive

Answer 5

Communicating (Non-obstructive) Hydrocephalus – Abnormal collection of CSF in the absence of any flow obstruction in the ventricles. Common causes usually involve the functional impairment of the arachnoid granulations, such as fibrosis of the subarachnoid space following a haemorrhage. Types Communicating without obstruction of CSF absorption Normal pressure hydrocephalus, overproduction of CSF Communicating with obstruction of CSF absorption Subarachnoid hemorrhage (SAH) Meningitis (bacterial and aseptic) Leptomeningeal carcinomatosis

Answer 6

(more common) Non-communicating (Obstructive) Hydrocephalus – Abnormal collection of CSF, with flow obstructed within the ventricular system. Obstruction at F. monro, aqueduct of sylvius or 4th ventricular outlet

Answer 7

In Arnold-Chiari malformation, the medulla and the tonsils of the cerebellum herniate through the foramen magnum and come to lie in the vertebral canal. Apertures in the roof of the fourth ventricle are blocked (F.Magendi adn F. Luschka), leading to obstruction to flow of CSF and internal hydrocephalus. Cranial nerves arising from the medulla are stretched. This is a congenital anomaly. It is often associated with syringomyelia. Symptoms: Dizziness Balance problems muscle weakness numbness amd tingling in arms or legs

Answer 8

-The herniation of the cerebellum into the spinal canal can cause a narrowing of the formen magnum, which can put pressure on the brainstem and block the flow of CSF -This pressure can lead to a backup of CSF and in some cases, it can even cause a small tear in the dura mater, leading to a CSF leak -CM is a fairly common cause of spontaneous CSF leaks, even without any trauma to the head or spine

Answer 9

Nonfusion of the neural tube can be associated with nonclosure or incomplete closure of the vertebral canal (spina bifida), leading to an opening in the spinal column, typically in the lower back. As a result of nonfusion of the neural tube neural tissue, such as the spinal cord and meninges, may lie outside the cranial cavity or vertebral canal. Types include: Myelomeningocele (most common and most dangerous) Meningocele Spina Bifida Occulta Spina bifida occulta – the mildest form, is characterised by an incomplete closure of the vertebrae, without protrusion of the spinal cord. Most people with this form of spina bifida are unaware of having it, and its discovery is often incidental. Meningocele (meningeal cyst) – where the meninges protrude between the vertebrae posteriorly, but the spinal cord is undamaged. Myelomeningocele – the most severe form, where a portion of the spinal cord remains unfused and protrudes posteriorly through an opening in the vertebral canal, in a sac formed by the meninges. This is associated with severe disability The opeining lesion in the spinla column causes CSF leakage which causes abnormalities in the shape and size of ventricles causing conditions such as chiarimalformation II or hydrocephalus - The amount of CSF produced is lower than normal, which can cause a build up of CSF within the brain - Flow of CSF can be impaired as SB acts as a 'road block'for CSF - These can lead to buildup of fluid, whichcan put pressure on the brain leading to hydrocephalus Cause; inadequeste intake of folate/folic acid during pregnancy symptoms: 1. weakness or total paralysis of the legs. 2. bowel incontinence and urinary incontinence. 3. loss of skin sensation in the legs and around the bottom – the child is unable to feel hot or cold, which can lead to accidental injury

Answer 10

Lumbar puncture is performed to obtain samples of cerebrospinal fluid (CSF) for various diagnostic and therapeutic purposes. In this procedure, a needle is introduced into the subarachnoid space through the interval between the third and fourth lumbar vertebrae. With the patient lying on his or her side, with the vertebral column well-flexed, the space between adjoining laminae in the lumbar region is increased to a maximum. Taking full aseptic precautions, the lumbar puncture needle is inserted into the vertebral canal above or below the third lumbar spine. An imaginary line joining the highest points on the iliac crests passes over the fourth lumbar spine and this is taken as a landmark to insert the spinal needle

Answer 11

Therefore, a needle for lumbar puncture is usually inserted between the third and fourth lumbar vertebrae (L3–L4) in the adult patient. In children, the caudal end of the spinal cord is usually located at the third lumbar vertebra (L3). Therefore, the needle for lumbar puncture is inserted at the L4–L5 level in children (Fig. 3.2A).

Answer 12

Typically 5 to 15 mL of the CSF is removed during the lumbar puncture to perform the cell count, protein analysis, and microbiological studies.

Answer 13

Occasionally, shunting procedures allowing the CSF to drain into the peritoneal cavity or the bloodstream are helpful if performed early in the course of this condition. Ventriculoperitoneal shunt

Answer 14

Caused by retrogade blood flow in the vertebral artery due to proximal stenosis (narrowing) and or occlusion of the subclavian artery (due to atherosclerosis). This flow reversal is known as subclavian steal The arm may be supplied by blood flowing in the retrogade direction down the vertebral artery at the expense of the vertebrobasilar circulation possibly depriving blood flow to the brain. Signs and symptoms syncope: fainting presyncope: sensation that one is about to faint neurologic deficits severe memory problems pins and needles in arms