neural tube defects Flashcards
where can neural tube defects occur
the brain and spinal cord
what type of NTD is meningomyelocoele and where is the most common location
one that results from incomplete closure of the posterior spine during early development
the lumbar spine is the most common location
what does the mass in meningomyelocoele contain
dysplastic: spinal cord, meninges, nerve root and CSF
what associated abnormalities are found in meningomyelocoele
Arnold chiari malformation
dislocated hips
bladder dysfunction (catheterisatsation is the solution)
lower extremity weakness
somatosensory loss
what are the two main types of NTD
Anencephaly
Spina bifida
what is the phenomenon in which nerves becomes trapped in the mass of meningomyelocoele
Tethered spinal cord
what happens in meningocele that does not happen in meningomyelocoele
the mass is covered by skin and you get minimal neurological deficits
- this is rare
meningomyelocoele is the common condition
what can you expect above the level of the meningomyelocoele lesion
nerve supply is usually normal unless there is a complication
can you expect flaccid paralysis in meningomyelocoele
yes, due to lower motor neuron damage
what happens when the lesion of meningomyelocoele is at L1
patients legs cannot be upright and they rely on wheelchairs to walk
what happens when the lesion of meningomyelocoele is at L4
Patients cant walk without the use of walking aid, less severe than L1 lesion thus they can use walking stick
what happens when the lesion of meningomyelocoele is at S2
patients have expanded leg curvature but can walk without the use of any aids
what happens in spina bifida occulata
the lesion does not pierce through the vertebral bones and is covered by skin
where is congenital dermal sinus usually found
between the nasal bridge and the sacrum
what characterizes congenital dermal sinus in the sacral region
covered by skin (which can be normal, pigmented or distorted by overlying mass)
may appear as a dimple or sinus (sometimes covered by hair and sometimes it is not)
what can congenital dermal sinus result to
may serve as tracts for infections within the dura mater and ultimately cause meningitis or abscess
the skin may be irritated
if the tracts expands into the thecal sac( the sac that contains the spinal cord) and form a mass cyst, the mass may appear as a tethered cord and in these circumstances cause bladder dysfunction.
how is encephalocoele diagnosed
by ultrasound
infant after delivery
what is encephalocoele
when there is extended brain tissue through the cranium
(could a result of cranial defect)
what MRI scan is used in imaging for encephaloceole
T2
What is Iniencephaly
it is a rare neural tube defect that involves the occiput and inion.
it is combined with rachischisis of the cervical and thoracic spine and also has retroflection of head
inion appears to have fused with the spine resulting in no discernible neck
what are the two examples of anencephaly
myeloschisis (missing roof plate, vertebral arch and skin)
rachischisis (more extreme)
what is exencephaly
disorder where the brain is located outside the skull
it is not a neural tube defect
what is holoprosencephaly
sequence of events that caused by the failure proncephalon to suffiently divide into double lobes of the cerebral hemisphere causing a single lobed brainstructure and severe skull and facial defects
the malformations are severe to an extent of death
what malformations are seen in the event of less severe holopronsencepaly
eye deformations
nose deformations
upper lip deformations
what are the cause of less severe holopronsencepaly
genetics
drugs
alcohol
gestational diabetes
