FAMILY HISTORY

The simple statement that there are no known diseases in the family is of no value. One must also know the number and sex of healthy family members to judge if there are individuals available who might have shown the abnormal trait. Information about consanguinity is also necessary, as consanguinity between parents increases the probability that the child will have a disease due to an autosomal recessive gene. In some situations tests are now available to diagnose the healthy carriers of an abnormal gene (see Chapter 6).

PREGNANCY

Events that occur during pregnancy may affect the fetus. Various infections, some of which the mother may have unknowingly, may pass to the fetus and cause active disease or permanent damage. Examples of such infections are syphilis, toxoplasmosis, cytomegalic inclusion body disease, rubella, and possibly other viral infections.

The possibility of the toxic influence of drugs became apparent during the 1960s when thalidomide caused malformations in children; this drug is no longer available. Antiepileptic medication, which usually has to be continued throughout pregnancy in a woman with epilepsy, may approximately double the risk of malformation in the child (see page 126), although these malformations do not usually involve the nervous system. Drugs with a cytostatic effect, such as azathioprine and cyclophosphamide, are even more dangerous to the developing fetus. Environmental toxins, particularly ethyl alcohol, may also seriously affect the child (see page 126).

Maternal disease, e.g. diabetes, may increase the incidence of malformations in the child, and untreated metabolic conditions, e.g. phenylketonuria (see page 127), may impair the development of the fetal brain. Smoking during pregnancy impairs the growth of the child but does not seem to cause malformations. Toxicosis of the mother increases the risk of placental insufficiency and thus the birth of an undernourished small-for-dates child.

Undernourishment of the mother during pregnancy, either general starvation due to lack of food or to lack of appetite and/or vomiting because of serious disease in the mother, or lack of specific substances such as vitamin B12 in a diet extremely lacking in all animal protein, may cause irreversible brain damage in the child. The incidence of abnormal children is slightly increased in pregnancies complicated by vaginal bleeding. It is debated whether this bleeding causes abnormalities in the child or whether it should be interpreted as a threatening abortion due to a primary abnormality of the fetus.

An estimation of the duration of the pregnancy, combined with an evaluation of the maturity of the newborn infant, is important. Preterm birth always carries a certain risk of intracranial bleeding and respiratory problems which may lead to asphyxia and brain injury. These risks are small for infants born after 34 or more weeks of pregnancy.

LABOUR AND DELIVERY

All information about labour and delivery is important in the neurological history of a child. Although the incidence of birth injury has diminished with improved obstetric and neonatal care, it still appears to be the most common single cause of neurological symptoms and signs during childhood. Although a birth injury may occur when delivery seems entirely normal, its incidence increases when there are complications such as premature birth, abnormal presentation, vacuum extraction, or evidence of fetal stress. It should, however, be emphasized that although the incidence of injuries is statistically increased, only a small proportion of infants born under unfavourable conditions will show permanent neurological symptoms and signs.

NEONATAL PERIOD

The neonatal period may be complicated by jaundice, cyanotic spells, respiratory difficulties, apnoeic attacks, or a bleeding tendency, any of which may be an indication of a disorder that may lead to neurological abnormalities. Neurological signs may also have been recorded in the neonatal period, e.g. abnormal cry, apathy, swallowing difficulties, inability to suck, abnormal muscle tone, tremor, or convulsions.

DEVELOPMENT OF THE CHILD

Questions about the psychomotor development of the child are a necessary part of the history. A few ‘milestones’ of the normal development of the infant born at term are briefly given here (see also Table 2.1, page 17). Information about these milestones is a necessary part of the developmental history. The motor development of the prematurely born infant is delayed, particularly during the first weeks and months, when the delay is roughly proportional to the degree of prematurity. The healthy premature baby usually catches up with the baby born at term during the first year of life.

The newborn baby is already able to follow a bright, slowly moving object with his eyes. He also turns his eyes towards the light. The infant starts to fix and give visual contact at the age of 4–6 weeks and to follow an object promptly a few weeks later. The first smile is seen at about the same time. Many newborn infants can lift the head in the prone position; all infants are expected to do so at 6 weeks of age. At 4 months of age the child can lift his head also in the supine position, can balance it when he is held upright, and can lift head and shoulders when lying on his belly. He reaches out for objects but is not yet able to grasp them deliberately; he examines and plays with his hands; he turns his eyes and head towards a sound; he can use his voice to express pleasure. A month or two later he starts to roll over. At the age of 7 months the child sits without support, he can grasp a rather large object in a clumsy way with his whole hand, and can transfer objects from hand to mouth. At 9–10 months of age the child starts to pull himself to standing and to walk holding on to furniture. He can pick up rather small things now, using the pinching grasp, and can transfer from hand to hand.

At 12–14 months of age most children start to walk without support and have a vocabulary of about three to ten words which may be understood by their parents. At 2 years of age the child is expected to be able to put at least two words together in a simple sentence and at 3–4 years to pronounce words distinctly and correctly without having to use baby-talk. The child is usually able to run at 2 years of age and to hop on one leg at 4½ years.

Normal psychomotor development usually seems to occur stepwise rather than smoothly. The normal variation is considerable. Thus, small deviations from the development outlined here should cause no concern. A thorough examination is suggested in the following situations:

The outlined deviations from the usual development do not establish that the child is developing abnormally,...