Neurology Flashcards
Most common cause of CP in term neonates in the US?
HIE
Most common neurologic complication of prematurity?
IVH
Most sensitive time for MRI for hypoxic ischemic brain injury?
24-96 hours
MRI at what time shows full extent of brain injury (HIE)?
10 days (between 7-21 days)
Gold standard for diagnosing seizures?
Continuous EEG
Are all neonatal seizures correlated clinically?
No, 80-90% of seizures have NO clinical correlation
When does edema peak in HUS for HIE?
24 hours
When can you see diffusion changes on MRI in HIE?
Present 7-10 days, then pseudonormalize
What is basal ganglia injury predictive of?
Severity of motor injury (Cerebral palsy)
What is posterior limb, internal capsule injury predictive of?
Ability to walk at 2 years
Most common type of neonatal stroke?
Arterial ischemic stroke
Most common presenting sign of stroke?
Seizures (>75%)
Name factors that decrease cerebral blood flow
Hypocarbia, hypotension, hypothermia and polycythemia decrease cerebral blood flow
An abnormality at which stage leads to anencephaly, and failure of what causes it?
Failure of the anterior tube closure during primary neurulation within first 26 days (weeks 3-4)
Maternal risk factors for anencephaly
Maternal hyperthermia, copper, zinc and folate deficiencies
Prenatal diagnostic factors for anencephaly
Elevated alpha fetoprotein
Polyhydramnios
Other anomalies: CDH, CHD, Trisomy 13 and 18, omphalocele
Detected on ultrasound at week 14-15
What abnormality leads to encephalocele and when does it occur?
Failure of closure of rostral tube during primary neurulation (weeks 3-4)
Most common location for encephalocele
Occipital
What is the prognosis of an encephalocele depend on?
The amount of brain tissue in the sac
Why do myelomeningoceles happen? (defect)
Failure of posterior neural tube
In which location are most meningomyeloceles?
Lumbar
What does prognosis of a myelomeningocele depend on?
Level of lesion (lower the lesion, better the outcome), also presence of other anomalies
What is an Arnold Chiari Type 1 malformation associated with?
Syringomyelia, hydromelia, skeletal anomalies (scolisos most common)
What is an Arnold Chiari Type 2 malformation associated with?
Myelomeningocele and hydrocephalus
Familial features associated with holoprosencephaly
Single maxillary central incisor
Ocular hypertelorism
Midfacial abnormalities
Aprosencephaly occurs due to a defect in?
Formation during the prosencephalic stage
Holoprosencephaly occurs due to a defect in?
Cleavage during prosencephalic stage
What changes in paCO2 and paO2 lead to increased cerebral blood flow?
Increase in paCO2 and decrease in paO2 cause increased CBF
Formula to calculate cerebral perfusion pressure
Mean arterial pressure - intracranial cerebral pressure
Changes in hemoglobin concentration and proportion of fetal hemoglobin leading to increased cerebral blood flow?
Decreased hemoglobin concentration
Increased proportion of fetal hemoglobin
Most common type of craniosynostosis? Caused by closure of which suture?
Dolicocephaly or scaphocephaly
Closure of saggital suture
Craniosynostosis that is associated with Crouzon and Apert syndrome
Frontal plagiocephaly
Unilateral closure of coronal suture
Craniosynostosis associated with Carpenter syndrome
Brachycephaly
Closure of bilateral coronal sutures
At what age does the anterior fontanel completely close by
Age 2 years
Syndrome with bilateral facial paresis?
Mobius syndrome
Secondary to hypoplasia or absence of cranial nerve nuclei
Cause of hypertonia (injury to which structure)
Corticospinal tract or extrapyramidal system
Persistence of palmar grasp is characteristic of
athetoid cerebral palsy
Normally disappears by 2-4 months
Where is the choroid plexus located
Atrium of lateral ventricles
When do choroid plexus cysts appear and disappear by? What syndrome can they be associated with?
Appear by week 11, disappear by week 26. Can be associated with trisomy 18
Major cation in CSF?
Sodium
At which gestational age do delta brushes appear and disappear on EEG?
Appear at weeks 29-30
Disappear at week 36-37 from central region and weeks 38-40 from occipital region
What is hypsarrhythmia seen with?
Infantile myoclonic spasms
What are central positive sharp waves seen with?
Premature infants with PVL
Most common pattern of cerebral injury seen with term HIE
Selective neuronal necrosis
Which artery is the most common site for focal cerebral ischemia
Left MCA. Left hemisphere is most commonly affected
Most common clinical sequela of PVL?
Spastic diplegia (lower extremities more affected than upper extremities)
Most common location of neuronal injury in hypoglycemia?
Bilateral, posterior occipital cortex
Which nerve roots are damaged in Erb-Duchenne
C5-C7
Which nerve roots are damaged in Klumpke’s
C8-T1
Where is the defect/pathogenesis in SMA type 1?
Lower motor neuron - degeneration of anterior horn cell
Inheritance pattern of SMA type 1
Autosomal recessive, chromosome 5
EMG features in neonatal myasthenia gravis
Progressive decline in amplitude with repetitive nerve stimulation, returns to baseline after a period of rest or administration of neostigmine
Inheritance pattern for myotonic dystrophy
Autosomal dominant, chromosome 19. Expanded repetition of CTG
Inherited almost entirely from mother
What determines the severity of congenital myotonic dystrophy
Number of CTG repeats
Muscle biopsy in congenital myotonic dystrophy
Abnormal: small and round muscle fibers, large nuclei, sparse myofibrils
EMG in congenital myotonic dystrophy
Myotonic changes eliciting a dive bomber sound
Prader Willi genetics
Deletion of 15q 11q13, some caused by maternal uniparental disomy
Deleted piece always of paternal origin
Prader Willi clinical triad
Hypotonia, cryptorchidism, poor feeding
Weight and growth pattern in Prader Willi
Failure to thrive during infancy, followed by obesity that presents between 6 months to 6 years
Most common location for intracranial tumor
Supratentorial
Most common presenting sign for an intracranial tumor
Increasing head circumference with bulging fontanel
Features of Sturge Weber
Port wine stain, facial hemangioma (distribution of 1st division of trigeminal nerve). Present at birth
Glaucoma
CNS ipsilateral tramline intracortical calcifications
Seizures
Hemiparesis
Features of tuberous sclerosis
Autosomal dominant Hypopigmented ash leaf macules, greatest on trunk or buttocks Cardiac rhabdomyomas CNS tumors Enamel pits in teeth Seizures
Features of neurofibromatosis
Autosomal dominant, chromosome 17
Cafe au lait spots, dont cross midline, have sharp borders, multiple
Freckling
Associated tumors: cutaneous neurofibromas, schwannoma, pheochromocytoma
Seizures
Features of McCune Albright
Irregular brown pigmentation Fibrous dysplasia of bones Precocious puberty Hyperthyroid Hyperparathyroid Pituitarty adenomas
Features of von Hippel Lindau
Autosomal dominant, chromosome 3 Increased tumor growth CNS tumor (hemangioblastoma, most commonly in cerebellum) Multiple systemic hemangiomata Retinal angiomas Pheochromocytomas
Most common type of CP with extreme prematurity
Spastic diplegia
Most common type of CP with bilirubin encephalopathy
Athetoid CP
Most common cause of multiple congenital contractures?
Amyoplasia
Cause of benign familial neonatal seizures
Potassium channel
Positive family hx
Gold standard for diagnosing neonatal seizures
Continuous EEG
Normal EEG pattern for premies?
Discontinuous, switches to continuous ~31 weeks
Delta brushes start disappearing ~36 weeks
Persistence of which reflex after 2-4 months is characteristic of athetoid CP?
Palmar grasp
Appears 28 weeks, well established 32 weeks, disappears by 2-4 months
What is an asymmetric Moro suggestive of?
Peripheral nerve injury
Persistence of tonic neck reflex after 6 months is suggestive of?
Focal cerebral abnormalities
Falx laceration that leads to subdural hemorrhage is a result of rupture of which vessel?
Inferior saggital sinus
Most common birth injury (excluding head stuff)?
Clavicle fracture
Horner’s syndrome is a result of injury to which nerve root?
T1
Most common traumatic nerve injury?
Facial nerve injury
How do you bypass flexor predominance in the neonatal period during an examination?
By assessing both pronation and supination
Signs of upper motor neuron dysfunction?
Hyperreflexia
HIE cooling temperature?
33.5°C to 34.5°C
Which anti-epileptic is most teratogenic?
Valproate
Which anti-epileptic has the most effect on cognition?
Valproate
