Neurology Flashcards
What embryonic age does primary neurulation occur? Secondary?
Primary (brain, spinal cord): 3-4 weeks
Secondary (meningocele, tetheted cord): 4-7 weeks
When would brain midline or cleavage defects occur (holoprosencephaly)?
2-3 months
What is the last pathway to myelinate?
Association bundle which connects the prefrontal cortex with temporal and parietal lobes (completes ~32 years!!)
What syndrome is associated with encephalocele?
Meckel-gruber syndrome (40% of patients with encephaloceles have other anomalies)
What maternal medications are associated with myelomeningoceles?
Valproate, carbamazepine
What level of myelomeningocele will make walking unlikely?
L2 and above
What are the types of Arnold Chiari malformation? (A primary neurolation defect)
Type 1 - only cerebellar tonsiles below foramen magnum (4th ventricle normal)
Type 2 - tonsils, 4th vent, choroid plexus, medulla displaced into spinal canal; associated with hydrocephalus
Type 3 - like a cervical meningocele, cerebellum and lower brainstem into sac
What is outcome of agenesis of corpus callosum?
Often normal if isolated. Higher incidence in people with dev delay. Increased risk of seizures later in life. Some assoc anomalies (holoprosencephaly, facial anomalies, cardiac, met disorders like nonketotic hyperglycinemia), trisomies
How to calculate cerebral perfusion pressure?
CPP= MAP - intracranial cerebral pressure
What causes decreased cerebral blood flow?
Low paCO2, high paO2, high hct, low fetal hemoglobin
What is Mobius syndrome?
Bilateral facial paresis. Caused by hypoplasia or absence of cranial nerve nuclei. No treatment or recovery
When is clonus normal?
5-10 beats normal in newborns, abnormal after 3 months
When does moro reflex appear? Disappear?
Appears: 28-32 weeks
Normal by: 37 weeks
Disappears: 6 months
Palmar grasp reflex
Appears: 28 weeks
Disappears: 2-4 months
*persistence is sign of athetoid cerebral palsy
How often is CSF remade?
5-7 hours, preterm: 10-30 ml; full term 40 ml. 99% water
What is the major cation in csf?
Sodium
What are delta brushes on eeg?
Signs of prematurity, appear 29 weeks, disappear at term
When does hypsarrythmia occur?
Usually after 2 months, in infantile myoclonic spasms
Features of Dandy Walker malformation
- Cystic dilation of 4th ventricle
- Cerebellar vermis hypoplasia or aplasia
- Hydrocephalus (75%), may not occur until months or years later
Symptoms of X-linked aqueductal stenosis
Aqueductal stenosis, adducted thumbs, agenesis of corpus callosum, mental deficiency
When HIE occurs are changes more in gray mayter or white matter?
White matter
What increases during hypoxia in HIE?
Increased:
- Cerebral blood flow
- Glucose influx to brain
- Glycogenolysis and glycolysis (to increase cAMP)
- Lacatate and H ions
- Excitatory amino acids, intracellular Ca, free radicals
What decreases during hypoxia in HIE?
Decreased:
- Oxidative phosphorylation
- Decreased brain glucose
- Phophocreatinine, ATP
What is most common artery for cerebral stroke in full term infant?
Left MCA (60%), right mca is 20%