DEVELOPMENTAL
NEUROLOGY
Department of Paediatric Neurology,
Masaryk University Hospital Brno
Infant Neurologic Assessment
• Infant Neurologic Assessment
reflects the ongoing maturation of the
central nervous system (CNS).
• This maturation is demonstrated by
the infant´s appropriate acquisition of
developmental milestones.
Embryology
• Formation of the CNS begins at 3-4 weeks
postconception with the appearance of the
neural plate.
• A neural grove appears and a formation of
the brain and spinal cord begins.
• Once the basic structures are in place,
neural cells proliferate at approx. 3 months
postconception and then migrate to their
final locations by 6 months of fetal life.
• At the end of this process all neurons
are present. Interference in either phase
can lead to a number of abnormalities
such as neural tube defects (e.g. spina
bifida, meningomyelocele),
microcephaly, lisencephaly etc.
• Development of the white matter
(myelinization) begins at early stages of
fetal life and continues, in the case of
oligodendrocytes, to many years
postnatal until myelinization is complete.
Developmental Screening
• At 4 months of age the infant should be
able to hold the head up and push up
on the arms when prone. A social
smile, laughter, and vowel sounds
should be present.
• Flaccidity or decreased muscle tone
(hypotonia) is evidenced by an outward
rotation at the hips with the legs
externally rotated in a frog leg position
• Assessment of the axial and neck
muscle tone is accomplished by the
traction maneuver – the infant lying
supine is pulled to a sitting position.
• Even in the full-term neonate the
extensor and flexor tone are balanced,
and the head is maintained briefly in
the axis of the trunk.
• At 4-5 months of age the infant should
be able to maintain the head in a
neutral position. Abnormal tone
(hypotonia) is indicated by the head
falling backward or requiring support
• Shoulder tone is assessed by holding
the infant in vertical suspension with
the examiner´s hands under the arms at
the armpits. The infant should hold in
that position with the arms remaining
flexed and no rise in the shoulders.
• Inability to maintain that position is
known as „slipping through“ and is a
mark of hypotonia
• Leg tone is assessed by placing the
infant in the vertical position with feet
on an examining surface.
• The 4-month old infant should be at
least momentarily able to support his
or her weight.
• Inability to support any weight is a
mark of hypotonia
• Extensor posture with crossing or
scissoring of the legs is a mark of
hypertonia (spasticity)
• The Denver II Developmental
Screening Test (DDST)
• the most widely used
developmental screening tool for
this assessment.
The Denver II Developmental
Screening Test (DDST)
1) Cognitive Milestones
A. Month 3-5: Attends to and Reaches for
objects
B. Month 4-8: Pulls string to secure a ring
C. Month 8-15: Imitates patting doll
D. Month 14-20: Finds Hidden Object
E. Month 18-28: Completes simple puzzles
The Denver II Developmental
Screening Test (DDST)
2) Language Milestones
A. Month 1.5-3: Squeals
B. Month 3.5-8: Turns to locate a voice
C. Month 9-13: Says Mama or Dada
D. Month 14-24: Combines two different
words
E. Month 21-36: Uses plurals
The Denver II Developmental
Screening Test (DDST)
3) Social and Emotional Milestones
A. Month 1.5-4: Smiles at others
B. Month 4-9: Seeks primary caregiver
C. Month 8-15: Stranger anxiety
D. Month 10-15: Displays 2 or more
recognizable emotions
E. Month 11-20: Exploratory play by self
F. Month 21-36: Cooperative play in small
groups
4) Gross Motor Milestones
A. Month 2-4.5: Rolls Over
B. Month 5-8: Sits without support
C. Month 10-14: Stands Alone
D. Month 14-20: Walks up steps
E. Month 21-28: Pedals tricycle
F. Month 30-44: Balances on one foot
G. By age 6: Rhythmic skipping
H. By age 8.5: Alternates foot-hop in place
I. By age 10: Holds tandem stance for 10
sec (eyes closed)
5) Fine Motor Milestones
A. Month 2.5-4: Grasps rattle
B. Month 4.5-7: Transfers cube hand to hand
C. Month 8-12: Has neat pincer grasp
D. Month 15-20: Builds tower of four cubes
E. Month 18-24: Imitates vertical line
F. Month 28-36: Copies circle
G. By age 5 years: Draws a square
H. By age 5.5 years: Tripod pencil grasp
I. By age 7 years: Draws diagonal line
J. By age 9: Draws cross with same
dimensions
K. By age 12: Draws three dimensional cube
6) Self Help Milestones
A. Month 4.5-8: Feeds self crackers
B. Month 10-14: Drinks from cup
C. Month 13-19: Removes clothes
D. Month 18-28: Washes and dries hands
E. Month 30-42: Dresses without supervision
F. Attained on average by age 4.5 years
1. Rides a bicycle with training wheels
2. Cuts paper with scissors
3. Colors inside lines
A. Attained on average by age 5.5 years
1. Ties shoelaces
2. Prints first and last names
A. Attained on average by age 6 years
1. Rides a bicycle without training wheels
The neurologic examination
of an infant younger than 1 year of age
can be divided into 3 parts
1) Evaluation of posture and muscle tone
2) Evaluation of primitive reflexes
3) Age-Invariable tests
Step 1. Lying supine
Step 2. Traction
Step 3. Rolling and prone position
Step 4. Suspensions (horizontal and vertical)
1) Evaluation of posture and
muscle tone
• Examination of the resting posture
• Examination of passive tone resistence
to passive movements
(„the scarf sign“ in the upper
extremities = hypotonia)
• Examination of active tone
(„the traction response“)
2) Evaluation of primitive
reflexes
• The evaluation of various primitive
reflexes is an integral part of the
neurologic examination of the infant.
With progressive maturation
(= myelinization) of the CNS some of
these primitive reflexes disappear =
they are gradually suppressed as the
higher cortical centers become
functional.
Moro reflex
• The Moro reflex is best elicited by a
sudden dropping of the baby´s head
backwards as he or she is held in the
examiner´s hands (or hitting the infant´s
pillow with both hands)
• Normally, there is an abduction and
extension of the upper extremities,
followed by an adduction and flexion
• It begins to disappear at 4 months of age
• Its absence during the first weeks of life
or persistence beyond 6 months of age,
indicates neurologic dysfunction
Other primitive reflexes
• Tonic Neck Response - the fencing
posture is assumed by the infant when
his head is turned quickly to one side
in the supine position.
• A positive response is extension of the
arm and leg on the side toward which
the face is rotated and flexion of the
limbs on the opposite side.
• The 4-month old infant should be able
to overcome this position.
• Babinski reflex – is elicited by
stroking the outside edge of the foot.
Extensor response of a great toe with
fanning of other toes is normal up to
1 year of age
• Beyond this age it is a mark of the
upper motor neuron dysfunction
• Palmar and Plantar Grasp reflexes –
symetrically positive in first 2-3 months
of age – later are covered up by
voluntary activity.
• Vertical Suspension (spasticity)
• Landau Reflex (hypotonia) – the
examiner lifts the infant with one hand
under the trunk, face downward.
Normally the infant lifts the head slightly
below the horizontal. In the hypotonic
infant the head falls down and the body
tends to collapse.
• Parachute Response
• The infant is suspended horizontally
around the waist, face down, and
suddenly projected toward the
examining surface
• He or she extends the arms to
protect the face – it appears between
4-6 months od age and persists
3) Age-Invariable tests
• Similar to those performed in
older children and adults
• Deep tendon reflexes
The main concerns of Child
and Developmental Neurology
1) Age-related epileptic
syndromes of childhood
2) Cerebral palsy
3) Disorders of mental
development
4) Neuromuscular disorders
1) Age-related epileptic
syndromes of childhood
• Early Infantile Epileptic Encephalopathy
(EIEE - Ohtahara syndrome). The disorder affects
newborns within the first three months of life
(most often within the first 10 days). Infants have
primarily tonic seizures, but may also experience
partial seizures, and rarely, myoclonic
seizures. Ohtahara syndrome is most commonly
caused by metabolic disorders or structural
damage of the brain. The EEGs of infants with
Ohtahara syndrome reveal a characteristic
pattern of high voltage spike wave discharge
followed by little activity. This pattern is known
as “burst suppression.”
West Syndrome (infantile spasms)
• Infantile spasms constitute a unique and frequently
malignant epilepsy syndrome confined to infants. The
usual characteristic features of this syndrome are:
• tonic or myoclonic seizures
• hypsarrhythmic EEGs
• mental retardation
• Infantile spasms are an age-specific disorder beginning
during the first 2 years of life. The peak age of onset is
between 4 and 6 months. Clusters of repetitive flexor
spasms (salams), head nods, often on awakening
• 15% to 30% unknown etiology (cryptogenic) Tuberous
Sclerosis or any brain abnormality
• EEG: Hypsarhythmia, high voltage slowing with chaotic
multifocal spike wave
• Treatment: ACTH, Oral steroids (Europe Vigabatrin)
Lennox-Gastaut syndrome (LGS)
• Characterized by a mixed seizure disorder. tonic
seizures and a slow spike-and-wave EEG pattern.
• The syndrome begins in children aged 1- 3 years .
Mental retardation is considered a component.
• The child with LGS typically has a mixture of seizure
types. The most frequently occurring are:
• tonic
• tonic-clonic
• myoclonic
• atypical absences
• "drop attacks"- a form of atonic, tonic, or myoclonic
seizures. The identifying EEG pattern in LGS is a slow
spike-and-wave discharge superimposed on an
abnormal, slow background, occurring at a frequency of
1.5 to 2.5 Hz.
Landau-Kleffner syndrome
• The Landau-Kleffner syndrome is a childhood disorder
consisting of acquired aphasia and epileptiform
discharges involving the temporal or parietal regions of
the brain.
• The typical sequence is as follows:
1. A seizure disorder develops in the child, but it is usually
well controlled with antiepileptic drugs.
2. Aphasia develops; its onset may be abrupt or insidious.
Unlike typical acquired childhood aphasia, receptive
dysfunction usually is the dominant feature early in the
course of the disorder.
3. Spontaneous verbal expression slowly becomes reduced,
and the child may use stereotypies, perseverations, and
paraphasias.
Childhood absence (pyknolepsy)
• A syndrome of typical absence seizures
(both simple and complex) in otherwise normal,
prepubertal children older than about 3 to 5
years. There is a strong genetic predisposition,
and girls are more frequently affected. The
absences are very frequent (occurring at least
several times daily), and tend to cluster.
• The absences may remit during adolescence, but
generalized tonic - clonic seizures may develop.
• The EEG reveals a bilateral, synchronous,
symmetric 3-Hz spike-and-wave discharge with
normal interictal background activity.
Juvenile myoclonic epilepsy (JME)
• Juvenile myoclonic epilepsy (JME), also known
as Janz syndrome, is a familial disorder that
typically begins in the second decade of life and
is characterized by mild myoclonic seizures,
generalized tonic-clonic (GTC), and occasionally
absence seizures. The average age of seizure
onset is 14 years.
• Janz described a familial disorder of myoclonic
epilepsy associated with an excellent prognosis
in patients who were otherwise mentally and
neurologically normal.
2) Cerebral palsy
• Cerebral palsy refers to a group of disorders
that affect a child's ability to move and to
maintain balance and posture. It is due to a
nonprogressive brain abnormality, occured
perinatally, which means that it does not get
worse over time, though the exact symptoms
can change over a person's lifetime.
• Children with cerebral palsy have damage to the
part of the brain that controls muscle tone and
coordination of movements. Initial central
hypotonic syndrome in a newborn usually
changes and spasticity develops
Types of cerebral palsy
• Spastic
• Spastic cerebral palsy is usually described further
by what parts of the body are affected. In spastic
diplegia, the main effect is found in both legs. In
spastic hemiplegia, one side of the person's body
is affected. Spastic quadriplegia affects a person's
whole body (arms, legs, and trunk).
• Athetoid or dyskinetic
• Ataxic
• Mixed
3) Disorders of mental
development
• ADHD - attention deficithyperactivity
disorder
• specific learning disabilities
• autistic spectrum disorders
4) Neuromuscular disorders
• Muscular dystrophies
(congenital – CMD, Duchenne/Becker
– DMD/BMD, limb-girdle – LGMD)
• Spinal muscular atrophies (SMA)
• Hereditary neuropathies
Charcot – Marie – Tooth (CMT)
Case Report
• Ester was a 4-month old female
with presenting complaints of
muscle weakness and failure to
gain developmental milestones.
• Family history was
unremarkable, and no peri- or
postnatal problems were noted.
• Her parents became concerned
when the girl was not rolling
over by 4 months of age.
• At the time of the paediatric visit,
she had no sucking or
swallowing difficulties.
• She had no history of respiratory
problems or pneumonia.
• She was noted to be hypotonic and was
referred to neurology for further
evaluation.
• She had markedly decreased muscle tone,
strength and deep tendon reflexes –
peripheral hypotonic syndrome was
evident.
• In the resting position she maintained a
frog leg posture.
• She had no head control on the traction
maneuver.
• She had no weight bearing in vertical
suspension, and an inability to support
her weight at the shoulders.
• The Moro and tonic neck responses
were absent.
• In summary, the girl had a normal
mental development, normal sensory
functions, and abnormal motor
development with peripheral
hypotonia and inability to perform
gross and fine motor skills.
• EMG showed a profound denervation
and loss of motor unit potentials
(MUPS), consistent with
Motor Neuron Disease (MND).
• DNA analysis revealed deletion of
exons 7 and 8 of the Survival Motor
Neuron 1 (SMN1) gene on the 5q
chromosome and verified the
diagnosis of Spinal Muscular
Atrophy (SMA) – Werdnig-Hoffmann
Disease.
Summary 1
• The neurological examination changes
as the infant develops. The most
marked changes occur during the first
year of life. The gross and fine motor
assessments are the most affected
because myelin formation and
cognitive development are essential to
the development of these skills.
Summary 2
• Age-related epileptic syndromes
(e.g. West or Lennox-Gastaut
syndrome) are a typical example
of how affections of the brain
during different stages of its
development result in different
clinical syndromes in paediatric
patients.