Neuro Flashcards
palmar reflex
one of the first, 26-28wks, strong by 32w, gone by 2-4 m - replaced by voluntary grasp
crossed extension reflex
30-34 wks, done by 2m. rub extended foot, other foot flexes, extends and toes spread, leg adducts
moro reflex
partial (spreading of arms) at 28-30w, full by 37-38w. Gone by 4-6m.
rooting reflex
starts at 28w, fully developed at 34 weeks, tests trigeminal n. Gone by 4m
tonic neck reflex/fencing
move head to one side slowly, that ipsilateral arm extends, the other flexes. latest to develop. 35w - 6m
what are common criteria accepted for TH?
hypoxia: Apgar <5 at 10 minutes, EGA >36 weeks, <6 hours since event, pH <7 or bd >16 in gas upto 1 hour of life
encephalopathy: moderate-severe based on sarnat criteria
what are three syndromes associated with craniosynostosis and how do they differ?
Crouzon: most common. +/- present with craniofacial abnormalities at birth, +/- hydrocephalus. Most commonly b/l coronal craniosynostosis.
Apert’s: less common. Do present with craniofacial abnormalities at birth. +/- hydrocephalus. MC b/l coronal synostososis. Polysyndactyly. May have devpt delay.
Pfeiffer’s: least common. Clover leaf deformity, b/l coronal suturues. Broad thumbs and great toes.
How do most encephalocele present?
In the east, most art frontobasal, in the West more are occipital. Most only have meninges and good prognosis.
How does DWS present?
Posterior fossa cyst, absent/hypoplastic cerebellar vermmis, +/- hydrocephalus.
Treated with VP shunt/cyst shunt or both.
What is a neuroenteric cyst?
a fluid filled cyst within the spinal cord, compresses cord and causes weakness in gait or pain. Tx: decompress.
What is diastometamyelia?
A septum (tissue/bone) causing two compartments of spinal cord. Can be two cords in one dura or one cord each in its own dura. Present with neurogenic bladder, leg weakness, orthopedic abnormlaities.
What is a lipomyelomeningocele?
It is a fatty connection from the spinal cord to the subQ tissue, can present with a dorsal appendage/tail. Symptoms will primarily include neurogenic bladder and bowel.
What is a dorsal dermal sinus?
sinus tract between spine and skin, can leak CSF, have recurrent meningitis. Needs to get excised. Can look like a spinal dimple far from gluteal cleft.
What did the MOMs trial show
When myelomeningoceles were repaired in utero, there was a decrease in chiari II herniation and hydrocephalus requiring shunting so the trial was ended early do to success. May have found increased incidence of tethered cord.
In myelomeningocele, what is prognosis based on?
The lower the lesion, the more the patient can do. L3 : can stand. L4-5: can ambulate. Most will be incontinent.
What is periventricular venous infarction?
Similar to peri-ventricular hemorrhagic infarction in preterm babies - an outpouching of the ventricle caused by hemmorhagic infarction after venous obstruction.
What is sinovenous thrombosis? (SVT)
This is a thrombosis in the sinus venosus. Often causes congestion –> edema –> hemorrhagic infarction. Consider heparin, consider obtain clotting factors. Most present within first 48 hours. Think about this dx in a term with IVH.
What is Neonatal Arterial Ischemic Infarction?
This is a thrombus in the intracerebral arteries causing an ischemic infarction. MCA is most common. Presents similarly to HIE/seizures but happens after a few hours of life.
If asymptomatic in neonatal period, may be symptomatic at a few months of age and present with handedness, called presumed perinatal AIS. associated with IVF.
What are the different findings of HIE on MRI?
T1, T2: T1 should should WM as white (myelinated). In neonates, internal capsule is one of the only things to be myelinated early. You may see posterior limb of internal capsule being less white (PLIC) indicating HIE. Obtain this at 7-21d of life to assess full degree, but not timing, of injury. T1-weighted images are ideal for depicting myelin, ischemia,
and subacute hemorrhage. T2-weighted images provide contrast between gray and white matter.
DWI: diffusion weighted imaging indicates restricted diffusion (dark). Best at 1-3 (5-7?)d of life, goes away by d7-10. Best for timing of injury.
MRS: best starting at 6h of life
How is an MRS helpful in HIE?
Lactate: NAA ratio can be informative. In HIE, lactate will be higher and NAA (N-acetylacetate, a marker for neuronal integrity) will be lower. So Lactat:NAA ratio will be higher in HIE.
Injury to which parts of the brain are associated with what pathology?
Globus Pallidus - kernicterus
b/l disease - metabolic
posterior parietal - hypoglcyemia
thalami/basal ganglia/WM - HIE
How does phenobarbital work?
It works on GABA mechanisms. In preterm babies, this mechanism is immature so it can actually be an excitatory response instead of inhibitory. Adding Bumetadine may help by causing Cl influx instead of efflux. With phenobarb, frequently still see subclinical seizures. Bumetadine has been associated with hearing impairment thought.
when does the blink reflex happen?
by 26 weeks, babies consistently blink in response to light. By 32 weeks, blink will remain as long as light stays present.
When is the pupillary light reflex?
CN II, CN III
Begins at 30w PMA, consistent by 32-35w
When do babies start to visually track?
by term, should be able to fixate and have limited tracking for something ~1 foot away
how much folic acid should women take?
400mcg daily pregestation, 4000mcg if hx of NTD
In what condition are babies likely to develop a latex alergy?
Myelomeningocele, 30-50% develop latex allergy
Which hydrocephalus is inherited?
X-linked hydrocephalus associated with adducted thumbs.
What is the role of glutamate?
Glutamate is an excitatory amino acid. Topiramate is a potential anti-seizure med that blocks glutamate. Decreased glutamate release by TH in HIE
What is the role of adenosine?
Adenosine suppresses fetal respiration. Theophyllines/caffeine are adenosine receptor antagonists.
What is the role of GABA?
GABA (gamma-aminobutryic acid) opens chlorie channels. It is excitatory in fetus and premature neonates due to high chloride content –> depolarization. Inhibitory in adults.
Phenobarb and benzo are gaba-ergic.
what is benign familial neonatal seizures
AKA 3rd day fits, usually resolve by one month. Potassium channel mutation.
what is benign idiopathic neonatal seizures
AKA 5th day fits, assc with clonic seizures and apnea, resolves in weeks to 1s month
where do congenital brain tumors usually exist?
supratentorium (rather than infra, which is common in childhood)
What is the most common CNS tumor, how do they typically present?
teratoma, usually from lateral ventricle > 3rd ventricle. May present with hydrocephalus, otherwise incidental. Seizures is uncommon.
teratoma > astrocytoma > craniopharyngeoma
Most supratentorial
bad prognosis
What is the classic triad of Sturge Weber
1) port wine stain over v1, v2 distribution
2) increased intraocular pressure/glaucoma
3) leptomeningeal involvement with vascular malformation/seizures
* *seizures are most likely clinical outcome** (85%, usually contralateral to port wine stain), developmental delay (75%), stroke like episodes