Neonatal Neurology

Question 1

Baby has asymmetrical Moro reflex on examination. What is your primary diagnosis? Any differentials? Bonus points for nerve roots affected.
What is a common mechanism of injury?
How would you investigate and treat?

Answer 1

Brachial plexus injury (C5/C6)
clavicle fracture
humerus fracture

Shoulder Dystocia during delivery where the shoulder is stuck on the pelvic outlet

Chest X-ray to outrule fractures
Physiotherapy, watchful waiting and referral to neurosurgery if it doesn’t resolve.

Question 2

Most reflexes are often suppressed by brain stem inhibition by 3-4 months. Some are normally lasting longer. Which reflexes are these?

Answer 2

Moro (up to 6 months)
Asymmetric Neck reflex (up to 7)

Question 3

Normal babinski sign in babies

Answer 3

Upward reflex in most normal babies which would have been positive in adults who would have a normal downward plantar reflex

Question 4

absence of a deep tendon reflex would indicate upper or lower motor neuron disease?

Answer 4

Lower motor neuron disease

Question 5

When does the sucking reflex develop?

Answer 5

32-34 weeks gestation => premature babies need NG tube to feed

Question 6

What is considered microcephaly
Give causes of microcephaly (5)
What is considered macrocephaly
Give causes of macrocephaly (3)

Answer 6

<2nd centile
TORCH especially CMV
Metabolic (phenylketonuria)
Alcohol (foetal alcohol syndrome)
Perinatal (hypoglycemia, hypothyroidism, hypoxia, meningitis)
Genetic (e.g. trisomy 13 and 18)
Neuroanatomical (Lissencephaly)

> 98th centile
Hydrocephalus
Subdural collections (oedema - succidenium , blood-cephalohematoma, lymphatic cysts)
Familial

Question 7

List the causes of generalized hypotonia in the newborn (5)

Answer 7

Neuromuscular pathway: CNS malformation (Lissencephaly), any neonatal encephalopathy, Intracerebral hemorrhage
Others: Genetic (Trisomy 21, Prader Willi), infections (sepsis, meningitis), Metabolic (hypoglycemia, hypothyroidism)

Question 8

What is Cerebral palsy?
What is it caused by?
How would it typically present? What type mostly presents?

Answer 8

Cerebral palsy is a disorder of movement and muscle tone caused by a !non-progressive injury! to the developing brain (e.g. intracerebral hemorrhage leading to hypoxic-ischemic encephalopathy leading to periventricular leukomalacia).

Although hypotonia might be an early manifestation of CP, Spastic CP (the most common type) presents with impaired movement, hypertonia, and hyperreflexia. May affect all 4 limbs (quadriplegia), lower limbs (diplegia), or one side affecting arm more than leg (hemiplegia)

Question 9

Therapeutic hypothermia (33-34 C) at is often used for neurological problems. How does this work? What is this usually administered for?
What is usually administered along with the cooling?
How long is this usually administered for?

Answer 9

Neonatal encephalopathy especially for hypoxic-ischemic encephalopathy. Works by preventing apoptosis (=> injury by cell death)
Supportive therapy and Sedatives (Midazolam) are usually administered with the cooling
Usually administered for 72 hours

Question 10

What are your ddx’s when it comes to an encephalopathy?

Answer 10

HIE
Non-ischemic encephalopathy: (infection, Lissencephaly) => always treat with antibiotics until infection is ruled out!!

Question 11

What is Lissenchephaly? This is the disease used as a ddx in many of the main topics.

Answer 11

It is a neuroanatomical issue where there is a gene-linked malformation causing the absence of convolutions/folds in the brain and microcephaly.

Question 12

What is the most common timing of injury in HIA?

Answer 12

Intrapartum (most common during delivery) >antepartum > postpartum

Question 13

What is neonatal encephalopathy characterized by?

Answer 13

It is defined by an altered level of consciousness accompanied by , hypotonia, seizures and a failure of spontaneous ventilation leading to reduced oxygen perfusion to the brain

Question 14

Give 3 RFs
List the main causes of HIE (3)

Answer 14

RF: Pre-eclampsia, IUGR, Gestation >41 weeks

Causes:
Placental: Cord prolapse, uterine rupture, cord rupture, placental abruption
Fetal: Fetomaternal hemorrhage

Question 15

An acute hypoxic-ischemic event may be presumed if any of the following are present (3)

Answer 15

Significantly abnormal fetal HR
Low umbilical cord blood pH
Low APGARs

Question 16

How would you evaluate how severe the neonatal encephalopathy is? Give detail

Answer 16

Think of the symptoms in the definition of NE
Sarnat Staging
Most imp are alertness, muscle tone, and presence of seizures.
NOTE: seizures are uncommon in the severe grade II NE because they are too flaccid to elicit a seizure.
Also note how in Grade I there is hyperalertness and excessive responses to stimulation. The disease varies significantly between grades

Question 17

What machine is used here?

Answer 17

CFM - cerebral function monitoring. It is a modified EEG. You would assess the amplitude of the brain’s electrical activity. The worse the encephalopathy is, the longer the periods of inactivity are. Here is an example of a severe NE

Question 18

What investigations would you carry out in a case of a baby presenting with generalized hypotonia, no seizures, and lethargy?
How would you manage this?

Answer 18

Case of NE
Investigations: Clinical examinations, EEG/CFM, capillary blood gas (for acidosis/lowpH) blood culture, FBC, TFTs, and glucose, Sarnat Staging, MRI for long term prognosis for seizures etc…

Management:
Emergency => ABC and ensure resuscitation and supportive measures are complete. Now think of symptoms
ischemia => Provide O2 support CPAP/mechanical + IV fluids to maintain circulatory volume and inotropes for contractility.
Seizures: Hypothermia therapy (+sedation with midazolam), monitor CFM/EEG brain activity, anticonvulsants if required (phenobarbitone)
Renal - SIADH - IV 0.9% to maintain fluid and electrolyte imbalance
Coagulopathy (from cooling or DIT) => Fibrinogen/FFP
Metabolic - !Hypocalcemia! and Hypoglycemia - Glucose infusion via dextrose

Question 19

What finding on an MRI would be related to risk of cerebral palsy? What would this finding also be consistent with?

Answer 19

PLIC - Posterior limb of Internal Capsule Injury
This is consistent with HIE

Question 20

When are MRI’s typically taken for HIE? What patterns are consistent with this disease?

Answer 20

taken typically 5-7 days of life
Strong signal intensity of frontal white matter indicates hypoxic injury.
PLIC - Posterior limb of Internal Capsule Injury
Basal ganglia (kernicterus) and Thalami injury
Watershed injury
Brain stem injury (high mortality)

Question 21

What are the main long term outcomes if HIE? (5)
What additional management would you give on discharge?

Answer 21

Cerebral Palsy, epilepsy, cognitive impairment, behavioral problems, death

Discuss followup within 6 weeks, refer to early intervention team (EIT), physiotherapy, speech and alnguage therapy, Occupational therapy, psychology, social work. basically a psych thing.

Question 22

Babies normally have myoclonic irregular jerks but that is normal and normal EEG such as in Benign sleep myoclonus. What are the 3 most common type of seizure in a newborn? Explain in terms of clinical manifestation and EEG finding

Answer 22

Clonic seizure: rhythmic jerks with abnormal EEGs
Subclinical: Only abnormal EEG.
Subtle: can show ocular signs like eye deviation or apnea. Variable EEG (can be normal or abnormal)

Question 23

What is a tonic seizure? (clinical manifestations only)

Answer 23

Stiffening and posturing

Question 24

A newborn is having a clonic seizure. Do you expect to see any findings on EEG?
Give 5 ddx

Answer 24

Yes, usually abnormal: VITAMIN C
Vascular (HIE, stroke, ICH)
Infective (Sepsis, meningitis, TORCH)
Traumatic hemorrhage (from birth?)
Autoimmune
Metabolic (hypocalcemia, hypoglycemia)
Iatrogenic (drug withdrawal)
Neoplastic
Congenital (genetic epilepsy, congenital brain malformation - Lissencephaly)

Question 25

How would you manage a seizure?

Answer 25

Supportive tx (ABCs)
Treat underlying cause (ALWAYS GIVE GLUCOSE, antibiotics until proven otherwise - ceftriaxone/cefotaxime, ampicillin)
Anticonvulsants (phenobarbitone)
Full EEG monitoring

Question 26

What is Benign Sleep Myoclonus?
When do the jerks occur in the sleep cycle?
How can you tell it is benign?

Answer 26

It is a brief involuntary and irregular movement of the limb due to contraction of a muscle.
Typically occurs during non-REM sleep

It is benign if there is abrupt and consistent cessation with arousal (waking up)
Note: May be induced by rocking motion
resolves by itself

Question 27

A neonate 3 days old presents with seizures and hemiparesis. Encephalopathy is ruled out. What is the likely diagnosis?
What may cause this?
What are risk factors for this?
What investigations would you carry out?
How would you treat?

Answer 27

Perinatal arterial stroke.
Cause: Thromboembolism
RFs: PPHN, ECMO, cardiac surgery
inv: FBC, EEG, Cranial US/brain MRI, thrombophilia screen, ECHO
tx: supportive. No heparin or thrombolysis

Question 28

Intracranial hemorrhages (ICH) is common in term babies but usually very small.
What is the most common location?
What are some RFs?

Answer 28

Subdural bleeds are most common
RFs: complicated delivery, bleeding disorder

Question 29

Give 3 types of extradural hemorrhages and their location
Which are benign and which can result in extensive bleeding and hypovolemic shock?

Answer 29

Caput Succedaneum (between skin and galea aponeurosis/periosteum)
Subgaleal hemorrhage (between galeal aponeurosis and periosteum)
Cephalohematoma (only one that is confined to a suture) (between periosteum and skull)

Caput and cephalohematoma are benign but subgaleal is severe.

Question 30

A baby presents with a claw hand. What is the most likely diagnosis? What mightv’e caused this?

Answer 30

Klumpke’s palsy
Breech delivery or traction of an outstretched hand

Question 31

Whenever a seizure is observed. What needs to be ruled out and hence managed immediately?

Answer 31

Hypoglycemia (always give glucose)
Meningitis (always give antibiotics, 3rd gen cephalosporin)

Question 32

What are the sequelae of a stroke in neonates?

Answer 32

Hemiplegia
Cognitive dysfunction
Epilepsy
behavioural problems