Neurodevelopment and Neurologic Examination

Nicole T. Baumer

Elizabeth Barkoudah

M. Zelime Elibol

INTRODUCTION

Understanding normal childhood development and deviations is essential to the pediatric neurologist, for it allows for identification of developmental disorder etiologies, understanding of clinical features, prognosis, and potential interventions. Developmental milestone assessment allows one to identify a delay, confirm normality, provide a quantitative measure of current functioning, and document longitudinal progress or regression.

DEVELOPMENTAL MILESTONES

Milestones

Organized according to separate streams (Table 1.1).

Developmental Quotient

An estimate of a child’s current level of functioning is often very accurate and aids in understanding of developmental concerns. Calculating a developmental quotient (DQ) in each functional area provides a quantitative measure of current functioning as it suggests when further evaluation should be performed.

DQ > 85 = routine developmental screening

DQ 75-85 = close developmental follow-up

DQ <75 = comprehensive evaluation

Neurobehavior and Adaptive Skills

Concomitant evaluation of neurobehavioral development and adaptive skills should be completed. Neurobehavioral disturbances are common in developmental disabilities. These can range from atypical (i.e., stereotypies), deviant (i.e., attentional aberrations), or maladaptive (i.e., noncompliance) behaviors. Adaptive skills, often referred to as self-help skills, require competence in motor and cognitive abilities at age-specific developmental level. Failure to attain success is not necessarily equivalent to having active deficits. Certain developmental failures, however, are important “red flags” (Table 1.2).

TABLE 1.1 Normal Developmental Milestones According to Age of Presentation

Age	Gross Motor	Visual / Fine Motor	Expressive Language	Receptive Language	Social Skills
0-2 wk				Alerts to sound
1 mo	Lifts head only	Visually fixes Follows to midline	Coos		Smiles socially Regards face
2 mo	Holds head in midline Lifts chest off table	Follows past midline			Recognizes parents
3 mo	Supports on forearms in prone	Follows in circular pattern Hand open at rest		Orients to sound	Reaches for familiar people or objects Smiles at reflection
4 mo	Lifts head prone to wrist Rolls prone to supine	Manipulates fingers Shakes rattle	Ah-goos		Enjoys looking around
5 mo	Rolls supine to prone Sits unsupported		Razzes
6 mo	Sits alone	Reaches with either hand Transfers Uses raking grasp	Babbles		Recognizes strangers
8 mo	Comes to sit Crawls		“mama”/“dada” indiscriminately
9 mo	Pivots when sitting Pulls to stand Creeps or cruises	Uses pincher grasp Finger feeds Looks to dropped items Probes with forefinger		Gestures	Starts to explore Plays pat-a-cake or peek-a-boo
11 mo			1st word “mama”/“dada” discriminately	1-step command with gesture
12 mo	Walks alone	Voluntarily releases Uses mature pincher grasp Drinks from cup	Immature jargon 2nd word		Imitates actions Comes when called Cooperates with dressing
14 mo			3rd word	1-step command without gesture
15 mo	Creeps up stairs Walks backward	Builds 2-block tower Scribbles	4-6 words		Solitary play
17 mo			Mature jargon 7-20 words	Identifies 5 body parts
18 mo	Runs Throws ball Pushes or pulls objects	Turns 2-3 pages Spoon-feeds	Says “thank you,” “stop it,” “let’s go”	Names 1 picture on command	Copies parents in tasks Recognizes self in mirror Shares enjoyment Points
19 mo			2-word combos	Identifies 8 body parts
21 mo	Squats Holds hand up stairs	Builds 5-block tower Drinks well from cup	2-word sentences 50 words		Asks for food Asks to use toilet
24 mo	Jumps in place Kicks ball Climbs stairs without help	Turns 1 page well Removes clothes, shoes Imitates pencil stroke Opens box, doors	Uses pronouns inappropriately	2-step command	Parallel plays Tolerates separation
30 mo	Throws ball overhead Jumps with both feet off floor	Unbuttons clothes Holds pencil in mature fashion	Uses pronouns appropriately Repeats 2 digits	Knows gender Understands the concept of “one”
3 y	Alternates feet up stairs Pedals tricycle	Dresses & undresses partially Copies circle	Uses 3-word sentences Uses plurals Minimum 250 words Repeats 3 digits	Knows full name Knows age Uses prepositions Identifies 3 colors Knows “what” questions	Group plays
4 y	Alternates feet down stairs Hops	Buttons clothing Catches ball Copies square	Asks questions		Tells “tall tales” Plays cooperatively with group
4.5 y				3-step command
5 y	Skips Jumps over obstacles	Ties shoe Copies triangle Spreads with knife	Uses adult sentence structure Asks what a word means	Knows home address	Plays competitive games Abides by rules Likes to help in household tasks

TABLE 1.2 Developmental Red Flags According to Age of Concern

Age	Red Flag
1 mo	Failure to alert, constantly irritable
2 mo	Rolling before 3 mo
3 mo	No social smile
4-5 mo	Poor head control, no laughing, no visual threat
6 mo	Not rolling, head lag
9 mo	W-sitting, scissoring, persistent primitive reflexes, absent babbling
12 mo	No protective reflexes, inability to localize sound
15 mo	No single words, persistent toe walking
18 mo	Hand dominance (before this age)
21 mo	Lack of social interaction
24 mo	Persistent poor transition, family does not understand speech
3 y	Extended family does not understand speech, persistent echolalic speech
5 y	Non-family members do not understand speech

PEDIATRIC NEUROLOGIC EXAMINATION

The pediatric neurologic exam mirrors, in many ways, the adult examination, but there are striking differences. The general physical exam is important and may aid in diagnosis; observation (behavior, motoric activity, social interaction) is a large part of exam. Key features, unique to the pediatric neurologic exam, include measurement of head circumference (HC), tone, and primitive reflexes. Below is a general outline of the basic examination. Should abnormalities be found in any area, a more comprehensive evaluation is warranted.

Measurements

Vital signs, weight, height, BMI calculation, and HC.

General

Routine HEENT, including fontanelles, lung, heart, GI, and skin exam.

Mental Status

Infants and young children—observations are primary assessment (environmental and visual attention, visual tracking, smile, social interaction, command comprehension and follow). Older children—evaluated with ageappropriate mental status testing (naming colors or objects, use of pronouns or prepositions, shape copy, coloring, writing or reading/comprehension).

Cranial Nerves

Full CN I-XII testing if cooperative. Infants and younger children—observation of spontaneous activity, quality and strength of cry, adequacy of suck and swallow, spontaneous eye movements, vestibulo-ocular reflex, response to light, visual threat, approach in visual fields, response to sound or loud noise (? startle).

Gross Motor

Observe baseline activity, resting posture, assess muscle bulk, range of motion, tone (ventral and horizontal suspension, head lag and axial). Often formal strength testing of specific muscles is not achievable and one must rely on observation (i.e., spontaneous movements, antigravity) as well as observation during play. Note dystonia, tremor, choreoathetosis, or other abnormal movements/dyscoordination.

TABLE 1.3 Primitive and Protective Reflexes

Reflex	Onset	Disappearance
Moro (startle)	Birth	2 mo
Walking (stepping)	Birth	6 wk
Rooting	Birth	4 mo
Asymmetric tonic neck (fencing)	1 mo	4 mo
Palmar grasp	Birth	5-6 mo
Plantar (Babinski)	Birth	˜12 mo
Galant	Birth	4-6 mo
Parachute	6-7 mo	Becomes voluntary
Anterior protection	4-5 mo	Persists
Lateral protection	7 mo	Persists
Posterior protection	9 mo	Persists

Fine Motor

Assess grasp (rake, pincer), crayon/pencil grasp and use, ability to fasten buttons, manipulation of small objects.

Sensation

Detailed exam often difficult, document symmetry of response to tactile stimulation. Response to subjective testing (i.e., position & vibration) often difficult and inconsistent.

Coordination

Observe during play (i.e., stacking blocks, ball catch/throw, balance one foot, running) and hand use.

Reflexes

In addition to typical stretch reflexes, primitive reflexes should also be assessed. Deviations from typical pattern should raise concerns (Table 1.3).

Gait

Observe for asymmetry, especially arm swing/posturing during walking (stressed gait, hopping, skipping) or running. Wide-based ataxic gaits may be normal during early ambulation.

DISORDERS OF HEAD GROWTH

The measurement of HC is vital. Longitudinal measurements are plotted on standard growth curves; adjust for prematurity until ˜24 mo of age. HC increases by 5 cm at these intervals, leading to the “rule of 3s, 5s, & 9s.” (See Table 1.4.)

Microcephaly

Defined as <2 SD (standard deviation) from the normal distribution for age. HC <3 SD generally indicates concurrent intellectual disability.¹^,²

Primary Microcephaly

Results from abnormal cerebral genesis.³ Evaluation requires assessment for known genetic etiologies.⁴

TABLE 1.4 Average Head Circumference by Age

Age	Average HC (cm)
Birth	35
3 mo	40
9 mo	45
3 y	50
9 y	55

Secondary Microcephaly

Results from injury to a previously normal brain. Etiologies include TORCH infections, HIE, metabolic diseases, or destruction from hemorrhage or stroke.

Macrocephaly

Defined as >2 SD from the normal distribution for age and results from a variety of causes,⁵ including subdural hematoma, external hydrocephalus,⁶ neurogenetic syndromes (leukoencephalopathies,⁷ chromosomal syndromes), neurocutaneous-vascular syndromes,⁸ or increased intracranial pressure (aqueductal stenosis, infectious causes, hemorrhage) (see Table 1.5).

TABLE 1.5 Representative Causes of Microcephaly and Macrocephaly

	Microcephaly	Macrocephaly
Anatomic	Neural tube defects, holoprosencephaly, lissencephaly, schizencephaly, polymicrogyria, pachygyria	Neurocutaneous disorders (Sturge-Weber, Klippel-Trénaunay-Weber), autism spectrum disorders, achondroplasia, cerebral gigantism, mass (cyst, tumor, abscess), hematologic (hemorrhage, arteriovenous malformation), primary bone disorders, hydrocephalus
Isolated	AR primary microcephaly type I-VI, X-linked microcephaly	Familial megalencephaly, pseudotumorcerebri
Metabolic	Maternal diabetes, phenylketonuria, methylmalonicaciduria, citrullinemia, NCL disorders, PDH, LD, infantile Krabbe	Leukodystrophies (Alexander, Canavan), lysosomal storage disorder (gangliosidoses, MPS)
Environmental	Congenital infection (TORCH, syphilis, HIV, enterovirus), meningitis, in utero toxin exposures (alcohol, tobacco, antiepileptic medications, cocaine), perinatal insult (hypothyroidism, hypopituitarism, hypoglycemia), ischemia, hypoxia	Toxins (lead, vitamin A deficiency or excess), meningitis, subdural hematomas
Genetic	Trisomies (13, 18, 21), Smith-Lemli-Opitz, Williams, Miller-Dieker, Wolf-Hirschhorn, Rubinstein-Taybi, Cockayne, Angelman, Cornelia de Lange, Rett	Fragile X, PTEN hamartoma syndromes, NF, TSC

ABNORMAL NEURODEVELOPMENT

Neurodevelopmental disability disorders are characterized by disturbance in developmental progress in one or more developmental domains. Prevalence of neurodevelopmental disabilities is ˜12%.⁹

Global Developmental Delay and Intellectual Disability

Terminology

Developmental delay can be limited to a single specific domain (language, motoric, or social) or several developmental domains.

Global developmental delay (GDD) diagnostically refers to delays in 2 or more developmental domains, should be reserved for children <5 y of age, and arises from a wide variety of causes.¹⁰^,¹¹ Intellectual disability (ID) is a disability characterized by significant limitation both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills¹²; measured by IQ testing in older children. Adaptive skills are those an individual must acquire to function within expectation in context of everyday life. At the core, both GDD and ID reflect disorders in learning. The diagnosis of GDD or ID should be made only after thorough evaluation and use of developmental testing.

Evaluation

Role of Pediatric Neurologist¹³: (1) Characterize and classify the precise neurodevelopmental disability. (2) Ascertain a possible underlying etiology (history, physical examination, selective laboratory and diagnostic testing). (3) Identify and arrange for needed supports

Only gold members can continue reading. Log In or Register to continue