pathology of nervous system Flashcards
1
Q
what is anencephaly
A
birth defect characterized by failure of formation of upper part of neural tube
2
Q
what are the risk factors for anencephaly
A
- folate deficiency: insufficient intake of folic acid before and during pregnancy
- maternal diabetes
- alcohol/ substance abuse
3
Q
what is spina bifida
A
type of neural tube defect that occurs during early fetal development
- failure of posterior part of neural tube to fuse
4
Q
3 main types of spina bifida
A
- spina bifida occulta; mildest form - small gap in one/ more vertebrae bones of spine (can appear as back dimples)
- meningocele; protrusion of membranes that cover spinal cord through vertabrae gap
- myelomeningocele; most severe/ common - when meninges and spinal cord protrude through vertebrae gap
5
Q
spina bifida sagittal U/S
A
- break in skin - occulta
- gap in vertebrae located in midline/ posterior of spine - sagittal view in ultrasound
6
Q
what is hydrocephalus
A
- build up of cerebrospinal fluid (CSF) in brains ventricles –> enlargement of skull and increases pressure
7
Q
what are the 2 types of hydrocephalus
A
- congenital hydrocephalus - obstruction to flow + reabsorption
- acquired hydrocephalus - due to disease eg tumors or brain bleeds (brain doesnt enlarge)
8
Q
what is communicating hydrocephalus
A
- ventricles + subarachnoid space freely communicating
- problem caused by lack of reabsorption of CSF/ blockage of lower subarachnoid space
9
Q
what is non-communicating hydrocephalus
A
- blockage of flow within ventricles
- one lateral ventricle
- bilateral
10
Q
by-pass procedures of hydrocephalus
A
- lateral ventricle into cisterna magna
- lateral ventricle into jugular vein
11
Q
lumbar puncture
A
- method of sampling CSF
- insert fine needle between two lumbar vertabrae in lower back in subarachnoid space that contains CSF
12
Q
cisternal puncture
A
- where lumbar puncture cannot be performed
- insert needle through back of head into cisterna magna (space at base of skull where CSF accumulates)
13
Q
CSF examination
A
- presence of blood always abnormal
- changes in iconic concentration
- changes in protein conc
- presence of infective organisms
14
Q
what can pressure be measured with for CSF examination
A
- measured with manometer
- increase CSF pressure –> ICP also increased
15
Q
why does increase in CSF pressure increase (intracranial pressure) ICP pressure
A
- exist within closed fixed space of skull
- limited space in brain to accommodate excess fluid
