J R Soc Med 2001;94:624-627
© 2001 Royal Society of Medicine
Cerebral palsy—medicolegal aspects
Ivan Blumenthal MRCP DCH
Royal Oldham Hospital, Rochdale Road, Oldham OL1 2JH, UK
E-mail:
ivan.blumenthal{at}norford.fsbusiness.co.uk
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INTRODUCTION
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In 1862 William James Little, a London orthopaedic surgeon wrote:
‘The object of this communication is to show that the act of birth
does occasionally imprint upon the nervous and muscular systems of the nascent
infantile organism very serious and peculiar evils. Nearly twenty years ago...
I showed that premature birth, difficult labours, mechanical injuries during
parturition to head and neck, where life had been saved, convulsions following
the act of birth, were apt to be succeeded by a determinate affection of limbs
of new-born children, spastic rigidity from asphyxia neonatorum, and
assimilated it to the trismus nascentium and the universal spastic rigidity
sometimes produced at later periods of
existence1.’
This condition was known as Little's disease until William Osler coined the
term cerebral palsy in 1888. He too noted the association with difficult
deliveries and with asphyxia requiring prolonged
resuscitation2. In
the 1890s Sigmund Freud was the first to recognize that antepartum and
postpartum factors could cause a similar condition. He postulated that most
cases arose from difficult birth but speculated that the birth difficulty
might have been caused by some underlying
condition2. The
asphyxia theory was subsequently given impetus when research in monkeys showed
that perinatal asphyxia could cause brain
damage3.
In the past 30 years, great increases in the use of fetal monitoring and
caesarean section have been driven by the belief that early detection of
asphyxia and speedy delivery will prevent brain damage. In parallel with these
changes there has been an unprecedented rise in malpractice litigation.
Surprisingly, over the same period the incidence of cerebral palsy in term
infants has not
changed4,5.
This lack of impact prompted epidemiological studies which showed that
asphyxia accounts for less than 10% of
cases6. In 1999 an
international consensus statement was published to provide an agreed reference
for use by the courts and expert witnesses in birth injury
litigation7. The
intention was to provide a template that could be modified as new knowledge
became
available8.
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ESSENTIAL CRITERIA
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How can the cause of cerebral palsy be established many years
after the
event? This is achieved by starting with the clinical
condition and working
backwards. The only type of cerebral palsy
associated with intrapartum hypoxia
is spastic quadriplegia,
especially if accompanied by
dyskinesia
9. Mental
retardation,
epilepsy and learning disorders are not caused by birth asphyxia
unless
also accompanied by spastic quadriplegia. A statement of severity
should
not be made before 3-4 years, because mild to moderate cerebral
palsy
improves in the early years and dyskinesia is not always
evident before then.
Abnormal tone will, however, have been
noticed earlier if the dyskinesia is
caused by hypoxia. Furthermore,
speech and cognitive development cannot be
accurately assessed
before age 3-4. There are several neurodegenerative and
metabolic
conditions that are slowly progressive and in their early phases
may
mimic cerebral palsy. Where there is doubt the child may
need to be seen again
after an interval. Syndromes such as Lesch—Nyhan,
Rett and glutaric
aciduria type 1 are examples.
Cerebral palsy caused by intrapartum hypoxia is always associated with a
neonatal encephalopathy and
seizures10,11.
Newborn encephalopathy is defined by Nelson and Leviton as ‘a clinically
defined syndrome of disturbed neurological function in the earliest days of
life in the term infant, manifested by difficulty with initiating and
maintaining respiration, depression of tone and reflexes, subnormal level of
consciousness, and often by
seizures’12.
This definition is applicable only to term infants because feeding difficulty
and abnormality of tone and reflexes are common in preterm infants.
The incidence of neonatal encephalopathy in a large study in Western
Australia was 3.8/1000 term
births13. That
study identified certain preconceptional and antepartum risk factors for
neonatal
encephalopathy14,
shown in Box 1. In 29% there
were both antepartum and intrapartum risk factors while only intrapartum
factors occurred in 4.9%. Spastic quadriplegia develops in about 10% of cases
of neonatal encephalopathy, all with
seizures11.
The inclusion of fetal acidaemia as an essential criterion in the consensus
statement has been criticized, as pH measurements are often not available. The
onus is now on maternity units to obtain that information at delivery.
Acidaemia is defined as a pH <7 or base deficit
>1215,16.
A normal pH excludes hypoxic encephalopathy. By contrast, a pH <7 is
associated with encephalopathy in only
10-20%15. The
majority of severely acidotic infants, born with a base deficit >16, are
also normal16.
In response to asphyxia there is an increase in fetal bloodflow to the
heart, brain and adrenals at the expense of the kidney, liver, intestines and
lung. Severe ischaemia frequently causes major organ dysfunction. Evidence of
organ dysfunction provides confirmation of intrapartum hypoxia. It is not,
however, an essential criterion, because there are instances of intrapartum
hypoxia without evidence of organ
dysfunction11,17.
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NON-SPECIFIC FACTORS SUGGESTIVE OF HYPOXIA
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Although meconium staining of the amniotic fluid is associated
with
increased risk of quadriplegic cerebral palsy, most children
born with
meconium in the liquor are
normal
18,19.
The Apgar
score, developed in 1952 by Virginia Apgar, remains a useful
means
of predicting neonatal survival, particularly when used
in conjunction with pH
values
20. It is
not, however, a sensitive
method for predicting neurological outcome and was
never intended
for that purpose. Over 90% of infants with a 5-minute score
of
0-3 will be
normal
21,22.
Even among infants who do not breathe
spontaneously for 20 minutes
three-quarters of survivors will
be
normal
23. It seems
that there is a fine threshold between
normality and death from asphyxia.
Fetal heart rate monitoring became established in the 1970s without proper
evaluation, and led to a dramatic increase in emergency caesarean sections for
fetal distress. According to a recent Cochrane review, the only benefit of
electronic heart rate monitoring was a reduction in neonatal
seizures24. Fetal
heart rate monitoring lacks specificity. For every case of encephalopathy with
an abnormal trace there are 83 normal babies with an abnormal
trace25. In
malpractice litigation, heart trace changes consistent with asphyxia
frequently give rise to the claim that an earlier caesarean section would have
prevented brain damage. There is no evidence to support such a
contention6,9.
The time between the decision to perform a caesarean section and delivery has
assumed importance in the medicolegal arena. A 30-minute interval is regarded
as the ‘gold standard’. Some hospitals have difficulty meeting
that arbitrary standard, which seems to be based on what is generally
achievable rather than evidence of potential
harm26.
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SENTINEL HYPOXIC EVENTS
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Sentinel hypoxic events are episodes of ischaemia that cause
hypoxic brain
injury in a neurologically intact fetus. For accurate
timing and a judgment on
possible sequelae, clear clinical signs
are required. In addition, the fetal
response to the event should
be demonstrable by heart trace and pH evidence
consistent with
asphyxia. Such events, which seldom result in cerebral palsy,
are
cord prolapse, placental abruption and uterine
rupture
27.
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OTHER CAUSES
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Certain factors such as prematurity, intrauterine growth restriction
and
microcephaly at birth suggest a cause other than intrapartum
asphyxia
7.
If two
siblings have cerebral palsy, particularly the same type,
a genetic cause is
likely. Multiple pregnancy is associated
with an excess risk of cerebral
palsy, the risk being highest
if one of the fetuses had died
in
utero. Fetal coagulation disorders
and maternal autoimmune disorders have
been linked with cerebral
palsy. The coagulopathy induced by these disorders
would explain
reports of placental thrombi and brain thrombi in stillbirths
and
neonatal
deaths
28.
Infection (chorioamnionitis) is now known to be an important factor for
cerebral palsy29.
It can mimic all the essential and non-specific criteria of intrapartum birth
asphyxia. In the past, many cases of cerebral palsy caused by infection were
wrongly attributed to birth
asphyxia9. There may
be no history of prolonged rupture of membranes or clinical evidence of
infection in the infant. Cytokines which are neurotoxic are generated by the
fetus in response to
infection30.
Ultrasonography early in the neonatal period shows evidence of brain injury
caused by
infection31. The
reason why the adverse effects are confined to a small minority of infants is
not clear.
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INVESTIGATIONS
|
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Imaging shortly after birth is useful in that it may reveal
evidence of
cerebral oedema—which confirms that the cerebral
insult is of recent
onset. Oedema develops in 6-12 hours and
clears in 4
days
7. Radiologists
do not always agree on the interpretation
of CT scans: the signs of cerebral
oedema may not be clearcut.
Ultrasonography, which is widely used in
neonatology, is likewise
open to differences in interpretation. In a recent
follow-up
study of normal babies, 20% had neonatal ultrasound
abnormalities
32.
After the neonatal period the main value of neuroimaging is to determine
whether the cerebral palsy is caused by a developmental brain abnormality,
intrauterine infection or some other congenital
abnormality33,34.
Since many children with cerebral palsy have brain malformations, neuroimaging
is an essential part of legal
proceedings35. MR
imaging in the infant is now a good predictor of future neurological status,
but when used many years later is not reliable in determining the cause or
timing of a brain
insult8.
|
LIFE EXPECTANCY
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The most important factors determining life expectancy are the
degree of
mental retardation, mobility and the ability to feed.
Population-based
cerebral palsy registers have been used to
gather information about life
expectancy. Differences in populations,
data collection methods and
definitions have resulted in wide
variation between studies. The median
survival for children
who are immobile and tube-fed is about 7
years
36. 80% of
children
with severe cognitive and ambulatory impairment survive to 18,
most
to 35 and beyond
37.
Life expectancy can be most accurately
assessed by an individualized
statistical assessment rather
than by simply matching degree of disability
with outcome in
the published studies (Strauss D, personal communication).
|
CONCLUSION
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From Little's observations in the middle of the 19th century,
a childbirth
litigation industry has been born. We now know
that birth asphyxia accounts
for only a small percentage of
this poorly understood condition. Meanwhile the
cost of medical
negligence payments has risen
sharply
38. Payments
to children
with cerebral palsy are some of the largest. These payments
now
regularly exceed £3 million, and in some cases lawyers'
fees exceed the
award. In Ireland a child was recently awarded
£2.1 million, with legal
fees almost double at £4
million
39.
With the
National Health Service currently facing a medical
negligence bill of
£2.6 billion, would not a no-fault
compensation scheme be kinder to
families and better for the
Treasury?
40
|
REFERENCES
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-
Little WJ. On the influence of abnormal parturition, difficult
labours, premature births, and asphyxia neonatorum, on the mental and physical
condition of the child, especially in relation to deformities.
Trans Obstet Soc Lond1862; 3:293
-344
-
Schifrin B, Longo L. William John Little and cerebral palsy. A
reappraisal. European J Obstet Gynecol2000; 90:139
-44
-
Myers R. Two patterns of perinatal brain damage and their
conditions of occurrence. Am J Obstet Gynecol1972; 112:246
-76[Medline]
-
Colver A, Gibson M, Hey E, et al. Increasing rates of
cerebral palsy across the severity spectrum in north-east England 1964-1993.
Arch Dis Child Fetal Neonatal Edn2000; 83:F7
-F12
-
Hagberg G, Hagberg G, Beckung E, Uvebrant P. Changing panorama of
cerebral palsy in Sweden. VIII. Prevalence and origin in the birth year period
1991-94. Acta Paediatr2001; 90:271
-7[Medline]
-
Stanley F, Blair E, Alberman E. Pathways to cerebral palsy
involving birth asphyxia. Clin Devel Med2000; 151:98
-108
-
MacLennan A. A template for defining a causal relation between
acute intrapartum events and cerebral palsy: international consensus
statement. BMJ1999; 319:1054
-9[Free Full Text]
-
MacLennan A. A guest editorial from abroad: medicolegal
opinion—time for peer review. Obstet Gynecol
Surv 2001;56:121
-3[Medline]
-
Nelson K. The neurologically impaired child and alleged malpractice
at birth. Neurolog Clin1999; 17:283
-93
-
Levene M, Sands C, Grindulis H, Moore J. Comparison of two methods
of predicting outcome in perinatal asphyxia. Lancet1986; 1:67
-9[Medline]
-
Evans K, Rigby A, Hamilton P, et al. The relationships
between neonatal encephalopathy and cerebral palsy: a cohort study.
J Obstet Gynaecol2001; 21:114
-20
-
Nelson K, Leviton A. How much of neonatal encephalopathy is due to
birth asphyxia? Am J Dis Child1991; 145:1325
-31[Abstract/Free Full Text]
-
Badawi N, Kurinczuk J, Keogh J, et al. Antepartum risk
factors for neonatal encephalopathy: the Western Australian case control
study. BMJ1998; 317:1549
-53[Abstract/Free Full Text]
-
Badawi N, Keogh J. Antepartum and intrapartum risk factors for
newborn encephalopathy. Contemp Ob/Gyn2001; 2:26
-54
-
Goodwin T. Clinical implications of perinatal depression.
Obstet Gynecol Clin Am1999; 26:711
-23
-
Low J. Intrapartum Fetal Surveillance. Is it worthwhile?
Obstet Gynecol Clin N Am1999; 26:725
-39[Medline]
-
Phelan J, Ahn M, Korst L, et al. Intrapartum fetal
asphyxial brain injury with absent multiorgan system dysfunction. J
Maternal-Fetal Med1998; 7:19
-22[Medline]
-
Naeye R. Can meconium in the amniotic fluid injure the fetal brain?
Obstet Gynecol1995; 86:720
-4[Medline]
-
Yeomans E, Gilstrap L, Leveno K, Burris J. Meconium in the amniotic
fluid and fetal acid—base status. Obstet Gynecol1989; 73:175
-8[Medline]
-
Casey B, McIntyre D, Leveno K. The continuing value of the Apgar
score for the assessment of newborn infants. N Engl J
Med 2001;344:467
-71[Abstract/Free Full Text]
-
Nelson K, Ellenberg J. Apgar scores as predictors of chronic
neurologic disability. Pediatrics1981; 68:36
-44[Abstract/Free Full Text]
-
Moster D, Lie R, Irgens L, et al. The association of Apgar
score with subsequent death and cerebral palsy: A population-based study in
term infants. J Pediatr2001; 138:798
-803[Medline]
-
Scott H. Outcome of very severe birth asphyxia. Arch Dis
Child 1976;51:712
-16[Abstract/Free Full Text]
-
Thacker S, Stroup D, Chang M. Continuous electronic heart rate
monitoring for fetal assessment during labour (Cochrane Review). In:
The Cochrane Library, Issue 2. Oxford: Update
Software, 2001
-
Spencer A, Badawi N, Burton P, et al. The intrapartum CTG
prior to neonatal encephalopathy at term: a case—control study.
Br J Obstet Gynaecol1997; 104:25
-8[Medline]
-
James D. Caesarean section for fetal distress. The 30 minute
yardstick is in danger of becoming a rod for our backs.
BMJ2001; 322:1316
-17[Free Full Text]
-
Nelson K, Grether J. Potentially asphyxiating conditions and
spastic cerebral palsy in infants of normal birth weight. Am J
Obstet Gynecol1998; 179:507
-13[Medline]
-
Nelson K, Grether J. Causes of cerebral palsy. Curr Opin
Pediatr 1999;11:487
-91[Medline]
-
Wu Y, Colford J. Chorioamnionitis as a risk factor for cerebral
palsy. A meta-analysis. JAMA2000; 284:1417
-24[Abstract/Free Full Text]
-
Yoon B, Romero R, Park J, et al. Fetal exposure to an
intra-amniotic inflammation and the development of cerebral palsy at the age
of three years. Am J Obstet Gynecol2000; 182:675
-81[Medline]
-
De Felice Toti P, Laurini R, et al. Early neonatal brain
injury in histologic chorioamnionitis. J Pediatr2001; 138:101
-4[Medline]
-
Haataja L, Mercuri E, Cowan F, Dubowitz L. Cranial ultrasound
abnormalities in full term infants in a postnatal ward: outcome at 12 and 18
months. Arch Dis Child Fetal Neonatal Ed2000; 82:F128
-33[Abstract/Free Full Text]
-
Sugimoto T, Woo M, Nishida N, et al. When do brain
abnormalities in cerebral palsy occur? An MRI study. Devel Med
Child Neurol 1955;37:285
-92
-
Hoon A, Reinhardt E, Kelley R, et al. Brain magnetic
resonance imaging in suspected extrapyramidal cerebral palsy: observations in
distinguishing genetic—metabolic from acquired causes. J
Pediatr 1997;131:240
-5[Medline]
-
Croen L, Grether J, Curry C, Nelson K. Congenital abnormalities
among children with cerebral palsy: more evidence for prenatal antecedents.
J Pediatr2001; 138:804
-10[Medline]
-
Eyman R, Grossman H. Living with cerebral palsy and tube feeding.
J Pediatr2001; 138:47
-
Hutton J, Colver A, Mackie P. Effect of severity of disability on
survival in northeast England cerebral palsy cohort. Arch Dis
Child 2000;83:468
-74[Abstract/Free Full Text]
-
Dyer C. NHS faces rise in negligence payments.
BMJ2001; 323:11[Free Full Text]
-
Birchard K. No-fault awards for babies with cerebral palsy in
Ireland? Lancet2000; 356:664[Medline]
-
Ferryman A. NHS faces medical negligence bill of £2.6bn.
BMJ2001; 322:108[Free Full Text]
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INTRODUCTION
ESSENTIAL CRITERIA
