The changing panorama of cerebral palsy in Sweden. VI. Prevalence and origin during the birth year period 1983-1986

The prevalence and origin of cerebral palsy in children born between 1983 and 1986 are reported. The crude live-birth prevalence was 2.49 per 1000; 1.56 for term births, 0.93 for preterm births. The increasing trend from 1970 persisted and was statistically significant for both groups. The most pronounced increase during 1983-1986 occurred in term cerebral palsy. The increasing use of neuroimaging techniques made the timing of damaging events more reliable. In term cerebral palsy, the origin was convincingly prenatal in 28% of cases and perinatal in 25%. The particular critical period for the brain damage underlying cerebral palsy was considered to be weeks 26-34 of gestation, i.e. when periventricular structures are extraordinarily vulnerable. In term infants, this occurs during late intrauterine life, while in the majority of preterms it occurs in early neonatal life. In total, two-thirds of cerebral palsy lesions might have been acquired during these decisive months of brain development.

Infantile hydrocephalus in preterm, low-birth-weight infants--a nationwide Swedish cohort study 1979-1988

All Swedish infants with shunt-treated infantile hydrocephalus, born during the period 1979-88 at < or = 34 weeks gestational age and of low birth weight, were studied. Ninety-six infants were born before 32 weeks and 50 at 32-34 weeks. The mean gestational age in the very preterm group gradually decreased from 29.5 to 27.3 weeks. The mean live birth prevalence was 15.9 per 1000 very preterm infants, and 5.1 per 1000 moderately preterm infants. No significant secular prevalence trends were found. The perinatal mortality decreased successively. The slowly decreasing trend in moderately preterm infants may imply better outcome in survivors. The slightly increasing trend in very preterm infants could be explained by more survivors in the low gestational age group. The aetiology was considered perinatal in 94% of the very preterm group and in 56% of the moderately preterm group; prenatal in 1% and 32% of infants, respectively. Additional neuro-impairments were present in 82% of infants, cerebral palsy being the commonest (74%).

Psychotropic drug use in pregnancy and perinatal death

The psychotropic drug use in mothers to all 73 perinatally dead infants in the city of Gothenburg, Sweden, in 1985-86, was compared to a control group of mothers to 73 surviving infants. Information regarding medication in pregnancy and pre- and perinatal data was collected retrospectively. In addition, serum samples obtained in early pregnancy were screened for benzodiazepines. Eighteen case-mothers used psychotropic drugs during pregnancy compared with 7 control-mothers. The association between psychotropic drug use and perinatal death was significant (p = 0.01). Psychotropic drug use and maternal disorder were closely correlated, but within the case group there were no significant differences between mothers using or not using psychotropic drugs in terms of age, parity or smoking habits. Although the etiology of death could be discussed in the individual infant, we find it noteworthy that the use of psychotropic drugs was so frequent in the mothers of perinatally dead infants.

Intrauterine growth in children with cerebral palsy

The risk of cerebral palsy in connection with intrauterine growth retardation has been analysed in a case-control study. The case series comprised 519 children with cerebral palsy born in 1967-1982 in the west health-care region of Sweden and the control series 445 children born during the same years in the same region. The risk of cerebral palsy in small-for-gestational-age infants was significantly increased in term and moderately preterm infants. The highest proportion among infants with cerebral palsy born at term was found in tetraplegia, followed by diplegia and dyskinetic cerebral palsy. It was concluded that small for gestational age on the one hand reflects early prenatal brain damage, and on the other mediates prenatal risk factors compatible with foetal deprivation of supply and also potentiates adverse effects of birth asphyxia and neonatal hypoxia.

Neurodevelopment in late infancy after prenatal exposure to benzodiazepines--a prospective study

Growth and neurodevelopment at 6, 10 and 18 months of age have been studied prospectively and longitudinally in a series of 17 children born to mothers who used benzodiazepines (BZD) in therapeutic doses as their only psychotropic drug throughout pregnancy. The results were compared with a group of 29 children born to mothers without any known use of psychotropic drugs. The BZD-exposed children caught up their low mean birth-weight, at an early stage, whereas the slightly decreased head circumference at birth remained at the same low level. In five infants, a pattern of craniofacial anomalies was found. Deviating neurodevelopmental and clinical symptoms and signs were common. The gross motor development was retarded at 6 and 10 months, but was nearly normal at 18 months. Impaired fine motor functions were found on all follow-up occasions. At 18 months, the most prominent finding was a delayed development of pincer grasp. The BZD-exposed children showed deviations in muscle tone and pattern of movements more frequently than children in the reference group. The study suggests that the use of BZD in therapeutic doses throughout pregnancy can have negative effects on the development of children up to 18 months of age. The long-term hazards cannot be evaluated from these results. A further follow-up at early school age is needed and is in progress.

The effect of benzodiazepines on the fetus and the newborn

The effect of the maternal use of benzodiazepines (BZD) on the fetus and the newborn infant has been studied in a representative series of 17 newborn infants (BZD group). The pregnancy and the perinatal period were characterized by 20 items. On the 2nd day of life, a neurologic investigation was performed and comprised a total of 38 items, subgrouped into items of reflexes/reactions, tonus, and other symptoms and signs. An optimum finding for each item was selected. The results were compared with a group of 21 newborns fetally exposed to psychotropic drugs other than BZD (drug group) and a reference group of 29 newborns with no known fetal exposure to drugs. Infants in the BZD group had a lower birth weight for birth length, as compared to both the drug group and the reference group. Significant differences in frequency of pre- and perinatal complications and in neuro-behavior between the BZD group and the reference group were found in all groups of items. We conclude that the use of BZD during pregnancy is associated with impaired intrauterine growth and an increased frequency of pre- and perinatal events. It affects the newborn infant neurologically mainly in the form of intoxication and withdrawal symptoms.

Epidemiology of absence epilepsy. III. Clinical aspects

Absence epilepsy was studied in a Swedish population, aged 0-15 years, in 1978-1982. Cases were selected by electroencephalographic criteria. In the 134 children with 3 Hz spike-and-wave discharges, 97 (72.4%) had absences alone or in combination with generalized tonic-clonic seizures (grand mal): 56 had absences alone, 31 absences followed by grand mal, and 10 started with initial grand mal. Two distinct groups could be discerned: 1) childhood absence epilepsy: onset before the age of 12, with a quick response to therapy, little or no risk of grand mal, and a high remission rate; 2) juvenile absence epilepsy: onset at the age of 12 or later, a very high risk of grand mal, and usually a good response to therapy, but a high risk of relapses at withdrawal. This classification of absence epilepsy into subgroups may be useful for prognostic guidelines.

Infantile hydrocephalus--the impact of enhanced preterm survival

The epidemiology of infantile hydrocephalus (IH) in the birth years 1983-86 was investigated in the south-western health care region of Sweden. The study was made as a continuation of a previous one which had shown a significant increase in the prevalence of IH in 1967-82. That rise was entirely referable to the relatively larger number of preterm IH infants born in 1979-82 and was considered to be due to the enhanced survival, especially of very preterm infants. The present series comprised 57 liveborn IH infants--27 preterms and 30 born at term. The livebirth prevalence of IH was 0.64 per 1,000, 0.30 for preterm and 0.34 for fullterm infants. The high prevalence of preterm IH infants in 1979-82 had persisted, but had not increased further. This might indicate an improved outcome in preterm survivors in the period 1983-86, as the survival rate had continued to increase. The striking predominance of a perinatal aetiology of IH in very preterm infants could be confirmed: 90% had had intraventricular haemorrhages verified by ultrasound in the postpartum period. The outcome in very preterm surviving infants with IH was still alarmingly poor: 78% had cerebral palsy, 72% mental deficiency, and 56% epilepsy.

Congenital malformations and maternal consumption of benzodiazepines: a case-control study

This study assessed potential teratogenic properties of benzodiazepine (BZD) intake during early pregnancy. Four neonatal diagnoses of congenital malformations (embryopathy and fetopathy, unspecified; unspecified congenital malformations of the nervous system; cleft palate and cleft lip; congenital malformations of the urinary tract) were selected. The authors' previous clinical experience had shown these diagnoses to be characteristic of infants born to mothers with excessive intake of BZD in early pregnancy. The selected diagnoses were present in 25 of 10,646 liveborn infants (2.3 per 1000) delivered by mothers living in the city of Gothenburg in 1985 and 1986. In 18 of these cases, it was possible to analyse maternal plasma, and eight samples (44 per cent) were found to be BZD-positive. Of 60 controls, two maternal blood samples (3 per cent) were positive for BZD. The difference is highly significant and suggests an association between these congenital malformations and BZD consumed during early gestation.

The changing panorama of cerebral palsy in Sweden. V. The birth year period 1979-82

The prevalence of cerebral palsy (CP) in Swedish infants born in the four-year period 1979-82 is reported and related to the prevalence in infants born during the twenty-year period 1959-78. In 1979-82 it was 2.17 per 1,000 livebirths, 1.23 for children born at term and 0.94 for preterms, which means that the rising trend since the beginning of the 1970s persisted. The most pronounced rise, from 0.18 per 1,000 livebirths in the period 1967-70 to 0.67 in 1979-82 was found in the subgroup of preterms with spastic/ataxic diplegia. The severity of motor disability and the relative frequency of mental retardation, infantile hydrocephalus and epilepsy among preterm CP children successively increased over the same period of time. The livebirth prevalence of CP in term infants increased slightly but non-significantly during the period 1967-82. The birthweight-specific prevalence of CP per 1,000 newborns surviving the first week of life increased in all birthweight groups during the period 1967-82, significantly for birthweights below 1,500 g and over 2,500 g. The rising prevalence of CP was concomitant with a parallel fall in perinatal mortality, especially in very preterm infants. In the 1980s, severely multi-handicapped, very preterm children, only exceptionally seen among CP children born in the 1960s and 1970s, has become a matter of concern.

Epidemiology of spastic tetraplegic cerebral palsy in Sweden. II. Prevalence, birth data and origin

The prevalence and origin of spastic tetraplegic cerebral palsy (TPL) was investigated in a population-based study from 15 Swedish counties and the city of Gothenburg. The series comprised 96 children and adolescents born in 1959-1978. The prevalence at the ages of 5-24 years was 8 per 100,000. The etiological analysis was based on the 91 TPL subjects, born in Sweden. The preterm rate was 7%. There were 46 males and 45 females. Excluding postnatal cases, the mean birth weight was 2949 g and the proportion of SGA 21%. An obvious prenatal origin was found in 21 (mainly microcephaly, other CNS maldevelopment, intrauterine CMV-infection), an obvious perinatal origin in nine (mainly cerebral hemorrhage), and an obvious postnatal origin in 16 (mainly CNS infection). A potential prenatal origin was considered in six, a combined pre- and perinatal in 15, a perinatal in 13 and in 11 the origin of TPL was untraceable. An optimality analysis showed that reduced optimality in the partum and postpartum periods discriminated between pre- and perinatal etiology of TPL. Cases with obvious perinatally derived TPL had a high load of complications in the partum and postpartum periods, whereas these periods had been fairly uncomplicated in cases with an obviously prenatal origin of TPL. - It was indicated that some 50-55% of TPL was prenatally, around 30% perinatally and some 15-20% postnatally derived. The low preterm rate as well as the proportion of perinatal brain damage in TPL cases has probably increased in recent birth year periods due to the appearance of very preterm, severely multi-impaired children in the CP panorama.

The changing panorama of infantile hydrocephalus and cerebral palsy over forty years--a Swedish survey

The time trends and background of infantile hydrocephalus (IH) and cerebral palsy (CP) are surveyed. The changes in live birth prevalence, disability patterns, associated neuroimpairments and distribution of etiologies are analysed. Both the risk of IH and that of CP sharply increase with decreasing birth weight and gestational age. It is concluded that the remarkably enhanced survival of particularly very preterm infants, those at the highest risk of long-term morbidity, implies an increasing number of impaired children as long as the outcome of survivors is not drastically improved. The data presented are thought to be of relevance as to reconsideration of the effectiveness of perinatal care for preterm babies.

Epidemiology of infantile hydrocephalus in Sweden: a clinical follow-up study in children born at term

The long-term outcome of infantile hydrocephalus (IH) in children born at term during a period of active shunt treatment was studied in a population-based survey. The series consisted of 68 children greater than or equal to 6 years old and born in 1967-78 in the south-western Swedish health care region. The clinical follow-up included neuro-paediatric assessment, Stott's test of motor impairment, the WISC test, CT and EEG analyses. Nineteen of the 68 children (28%) had cerebral palsy, 17 (25%) minor motor dysfunction and 32 (47%) no motor dysfunction; mental retardation was present in 26 (38%), 16 with an IQ 50-70 and 10 with IQ less than 50; 42 children (62%) had normal intelligence and epilepsy was found in 15 (22%). Compared with a non-shunted IH series from the 1950s, the survival of IH children had considerably increased. Of constituents characterizing the IH syndrome from the time prior to shunting, ataxia, divergent squint and the special "Cocktail-party behaviour" had significantly decreased, all of which conditions are highly related to chronic expansion of the ventricular system. The frequencies of other impairments such as mental retardation and epilepsy were fairly similar, reflecting the present increased survival of IH children with primarily non-IH-dependent brain damage. IH children with associated brain parenchymal defects had the poorest outcome, and those without had in general a much more favourable one. Thus the single most important factor for the outcome of IH was found to be the presence or absence of associated primary brain damage or maldevelopment.

Epidemiology of infantile hydrocephalus in Sweden. Current aspects of the outcome in preterm infants

The outcome in a population-based series of 61 Swedish preterm infants born in 1967-82 with infantile hydrocephalus (IH) was investigated. Sixteen (26%) died before the age of two years. The available information was updated when the 45 surviving children were at least four years and six months old. A structured follow-up examination was performed in the 13 children who had passed the age of six years. Among the 45 survivors, 47% had cerebral palsy, 51% mental retardation and 33% epilepsy. The overall outcome for preterm infants with IH was found to be poorer than that for fullterm ones. Prognostic factors correlating to a poor outcome were an obvious origin of IH (pre- or perinatal) and a gestational age of less than 28 weeks. It is concluded that handicapped IH children born very or extremely prematurely constitute a new, and to a large extent severely brain-damaged group that has entered the Swedish IH panorama since the end of the 1970s.

Epidemiology of infantile hydrocephalus in Sweden. Reduced optimality in prepartum, partum and postpartum conditions. A case-control study

The optimality concept developed by Prechtl was adopted to investigate a population-based series of infantile hydrocephalus (IH). The results were compared with those from a control series of newborns. The case series comprised 128 IH children born at term and 50 born preterm, and the control series 269 and 176, respectively. Cases with a prenatal cause of IH, as compared with those with a perinatal cause and controls, had significantly increased risk of IH by reduced optimality in the prepartum period. Peaks in the flow of non-optimal items in the prenatal group were repeated abortions or perinatal death in previous pregnancies, maternal disorder and twin birth. The profile of reduced optimality in term IH cases of undefined cause was similar to that of term cases with a prenatal cause. All IH cases had significantly increased reduced optimality in the postpartum period compared with controls. The increase was massive in cases where IH was of perinatal cause, with peaks in items of acidosis, apnea, respiratory treatment, infection and cerebral irritation. Reduced optimality in partum conditions did not discriminate between IH of pre- and perinatal cause. Reduced optimality in the prepartum, partum and postpartum periods in IH children, as compared with those with cerebral palsy syndromes, was nearly identical to that of hemiplegic, and significantly lower than that of diplegic and dyskinetic, cerebral palsy.

Epidemiology of infantile hydrocephalus in Sweden. II. Origin in infants born at term

The aetiology of infantile hydrocephalus (IH) was studied in a population-based series of 141 children with IH, born at term in southwestern Sweden 1967-82. A prenatal aetiology was present in 81 children (57%), a pre- and perinatal in 6 (4%), a perinatal in 27 (19%), and a postnatal in 8 (6%); the origin in 19 children (13%) remained untraceable. A variety of aetiologies were revealed or indicated among prenatal conditions. The dominant intrauterine infection was toxoplasmosis. The predominant perinatal condition was posthaemorrhagic IH. The broad outline of outcome differed between pathogenetic groups. Children with a clear prenatal onset of IH were found to be at high risk for early death or multiple neurological impairments. Thirteen of 63 (21%) within this group had died before 2 years of age and 34 of the 50 (68%) survivors showed major neurological dysfunction. This contrasted to the incidences of 3% deaths and 30% sequelae in children with IH of other onset.

Epidemiology of infantile hydrocephalus in Sweden. III. Origin in preterm infants

The aetiology of infantile hydrocephalus (IH) was studied in a population-based series of 61 children with IH born 1967-82 at less than 37 weeks of gestation. A prenatal origin was present in 17 children (28%), a pre- and perinatal in 17 (28%), a perinatal in 26 (43%) and a postnatal in one (1%). The predominant single cause was postaemorrhagic IH, which was diagnosed in 19 (31%). In addition, an undiagnosed cerebral haemorrhage was considered to be the cause in another 25%. The outcome differed between pathogenetic groups. Children with a clear onset of IH (pre-, peri- or postnatal) were found to be at high risk for early death or multiple impairments. Sixteen of 39 (41%) within these groups had died before 2 years of age and 18 of the 23 (78%) survivors showed major neurological dysfunction. This contrasted to no mortality and 41% major dysfunction in children with a less clear onset of IH. A new subgroup consisting of infants born before 28 weeks of gestation emerged in the early 1980s. All infants with IH in this group developed a severe multihandicap condition.

Epidemiology of infantile hydrocephalus in Sweden. I. Birth prevalence and general data

The livebirth prevalence of infantile simple hydrocephalus (IH) was investigated in a Swedish population-based survey. The study comprised all liveborn infants with IH apparent before the age of one year and born in the study area between 1967-82. A total of 202 infants fulfilled these criteria; of these, 141 (70%) were born at term and 61 (30%) were preterm. The mean prevalence was 0.53 per 1,000, with a slightly increasing trend from 0.48 in 1967-70 to 0.63 in 1979-82. The increase was entirely referable to the preterm group, in which the prevalence rose from 0.13 per 1,000 in 1967-70 to 0.30 in 1979-82. There was no tendency to an increase in the term group. In 12 of 23 children born very preterm the origin of the IH was a diagnosed cerebral haemorrhage. This is compatible with the increased risk of the latter condition that has been found in very preterm newborns. The mortality among children with IH was highest before the age of one year (15%), after which it was 1.2% per year.

The changing panorama of cerebral palsy in Sweden. IV. Epidemiological trends 1959-78

From a population-based series of 773 patients with cerebral palsy (CP) born in 1959-78, an analysis was made of the epidemiological trends over this period of 20 years, divided into five 4-year periods with emphasis on the last two. After a significantly decreasing incidence of CP in the first three periods (1959-70) from 1.9 to 1.4 per thousand, there was a significant increase in the last two periods, reaching 2.0 per thousand in the period 1975-78. Both the decreasing trend in the earlier periods and the increasing trend in the more recent ones were mainly referrable to spastic/ataxic diplegia in preterm CP, and to dyskinetic syndromes in CP infants born at term. With respect to pathogenesis, the corresponding changes in CP incidence were mainly accounted for by the group with potential perinatal risk factors. When analysed on the basis of surviving babies in birth-weight-specific groups, the incidence of CP in 1971-78 was found to have increased in all groups, but this was only statistically significant in the low birth weight group of 2 000-2 500 g. Changing trends in incidences ran parallel with a steadily progressive decline in perinatal mortality through all five periods. A considerable and cumulative net gain of surviving non-CP children was continuously achieved; this was also true for 1970-78, in spite of an increasing CP morbidity during these last two 4-year periods.

Recurrences after initial dislocation of the shoulder. Results of a prospective study of treatment

During the years 1978 and 1979, the results in 257 patients with a primary anterior dislocation of the shoulder were prospectively studied. The patients were less than forty years old and had been treated at twenty-seven Swedish hospitals. Thirty-two patients had a fracture of the greater tuberosity, but none of them reported having any further dislocations within two years after treatment, while 32 per cent of the patients without this fracture had a redislocation during the same period. The incidence of fractures of the greater tuberosity varied with the age of the patient; the highest rates were in the age groups of twelve to thirteen years and thirty-four to forty years (43 and 30 per cent, respectively), while in the age group of twenty to twenty-two years this injury was found in only 3 per cent of the patients. Chip fractures of the glenoid rim were found in 8 per cent of the patients, most of whom were in the older age groups. Impression fractures in the posterior part of the humeral head were demonstrated in 55 per cent of the patients and were not associated with a significantly higher rate of recurrence of dislocation. One hundred and twelve patients used an immobilization device for three to four weeks, while 104 patients began to use the shoulder as early and as freely as possible. At the two-year follow-up the groups showed an equal rate of recurrence of dislocation. In the age group of twenty-two years or younger nearly 50 per cent of the patients had one or more recurrences, regardless of treatment. In the two older age groups (twenty-three to twenty-nine and thirty to forty years old), the incidence of recurrence was 25 per cent or less.

Diplegic cerebral palsy in Swedish term and preterm children. Differences in reduced optimality, relations to neurology and pathogenetic factors

An unselected series of 93 Swedish diplegic children born in 1969-1976 and subgrouped into 49 term (TDC) and 44 preterm (PDC) cases were analyzed for differences in reduced optimality in pre- and perinatal conditions, these also being related to degree of handicap, associated neurology and conventional pathogenetic grouping. Comparisons of the reduced optimality with those of a dyskinetic and a control series were also made. TDC were shown to have more severe handicaps and more additional neurologic abnormalities than PDC. The profile of reduced optimality was weighted in TDC to items pointing to fetal maladjustment/deprivation and birth asphyxia and in PDC to items accompanying preterm birth and to postpartal items. The optimality of diplegics was in general more reduced than in controls and less than in dyskinetics. This was especially true for TDC. Differences in the background mechanisms of the diplegia between TDC and PDC were indicated from dissimilarities in the combined patterns of reduced optimality and conventional pathogenetic grouping. Postpartal complications predominated among PDC. A prepartal factor as the only cause of the diplegia was likely in 41% of TDC, and as a contributory cause in another 24%. Birth asphyxia, present in 31% of the TDC, was never the only risk factor among infants born at term.

Reduced optimality in pre- and perinatal conditions in a Swedish newborn population

The optimality concept of Prechtl was adopted for the investigation of a series of 229 newborn infants, selected by paired sampling as controls to 116 dyskinetic cerebral palsy cases. A list of 34 conditions, subgrouped into 14 prepartum, 10 partum and 10 postpartum items, was designed and criterias for optimality were defined. When a condition fell short of criteria for optimality, the infant concerned was given a non-optimal point. The sum of non-optimal points for each infant was defined as the reduced optimality score and the proportion of non-optimal points as the reduced optimality rate. The self-weighting capacity of the reduced optimality score system was confirmed. Lack of optimality compared to optimality in a particular item was generally related to a significant increase of the reduced optimality rates of remaining items. Reduced optimality compared to optimality was in the prepartum period significantly more often followed by reduced optimality than optimality in the partum and postpartum periods. In clinical categories--preterm birth, low birth weight, small for gestational age, and combinations of these--a significant increase of the reduced optimality rates were found. Outcome in items comparable to vital statistics were all close to the expected. The series was considered representative for Swedish children born during the period from 1959-70.

Mild mental retardation in Swedish school children. II. Etiologic and pathogenetic aspects

The etiology and pathogenesis of mild mental retardation (MMR) (IQ 50--70) were analysed in an unselected series of 91 Swedish school children with this condition born 1966--70. The cause was considered to be prenatal in 23%, including 5% genetic, prenatal unknown in 10% and alcohol fetopathy in 8%. A perinatal cause--mainly asphyxia combined with fetal deprivation--was found in 18% and a postnatal in 2%. In 55% the cause was untraceable. Half of these latter children had close relatives with below-average intelligence. Exceptionally low birth weights and lengths were revealed among the 8% with alcohol fetopathy. Neurological abnormalities were found in 43% of the children, epilepsy in 12%, cerebral palsy in 9% and a clumsy child syndrome in 23%. Psychiatric disturbances were present in 31%.--The types and multitudes of predisposing background factors in MMR were compared with those in severe mental retardation and with those in the IQ group 71--75. The general conclusion is drawn that in Swedish school children negative pre- and perinatal factors are today responsible for a larger proportion of MMR than has previously been known.

Mild mental retardation in Swedish school children. I. Prevalence

In an unselected series of Swedish school children born 1966-70, the prevalence of mild mental retardation, defined as an IQ of 50-70, was determined. A prevalence of 0.4% was revealed. The findings in this study, supported by recent IQ analyses in other Scandinavian countries, indicate that a true prevalence for the IQ range 50-70 was ascertained. The high average social standard and early social stimulation are put forth as a likely explanation for the low prevalence of mild mental retardation in Swedish preschool and school children.

Arthroscopic visualization of the posteromedial compartment of the knee joint

Introduction of the arthroscope in the midline through the patellar tendon about 1 cm. below the apex of the patella is described. The posterior compartments of the knee joint can be examined from this single entry. The technique has been used in 1232 patients without any complications. In 127 patients subjected also to arthrotomy the arthroscopic diagnosis proved to be correct in all instances except for one missed rupture of the posterior cruciate liagment. In that case a bucket handle rupture of the medial meniscus prevented the entry into the posteromedial compartment.

Arthroscopic examination of the posteromedial compartment of the knee joint

In a series of 356 arthroscopies of the knee joint 127 patients were explored by arthrotomy. A Storz arthroscope was introduced through the patellar tendon, and we alternated between the 30 degrees and 70 degrees optical systems in the same trocar sheath. The 30 degrees system was used for inspection of the superior, anterior, medial and lateral compartments, and to lead the tip of the instrument to the posterior part of the joint. The 70 degrees telescope was then used, providing a good view of the posterior cruciate ligament and the posterior horn of the menisci and their attachments. It also allowed direct inspection of the posterolateral and posteromedial compartments. No major diagnostic error was made by the arthroscopist in the 127 patients operated on as a result of the findings of endoscopic examination. Arthroscopy with the use of both 30 degrees and 70 degrees telescopes at the same session gives high diagnostic accuracy and detailed, exact pre-operative diagnosis.

Therapeutic arthroscopy of the knee

This paper describes transcutaneous therapeutic procedures performed during arthroscopy. Sixty-six patients were treated. Small loose bodies were flushed out through the arthroscope in 7 cases. In 19 of 24 knees a loose body 0.5-2 cm in size was extracted either with a Dormia stone-dislodger or a pituitary rongeur. In 5 patients we failed to remove the loose body transcutaneously and arthrotomy was performed. A meniscus was resected in 17 patients using a pituitary rongeur alone or in combination with some other instrument. The late result was good in 14, but 3 subsequently underwent arthrotomy. Various procedures such as lateral release of the patella by a special technique, removal of intra-articular sutures and other measures were also undertaken. No complications occurred and the duration of sick leave was usually short. Before arthrotomy for removal of loose bodies or resection of ruptured menisci is performed, we feel that an attempt at transcutaneous therapy under arthroscopy should be made.

Findings at arthroscopy and arthrography in knee injuries

The diagnostic accuracy of arthroscopy and arthrography was investigated. A total of 135 patients were examined by the two methods. All were operated on and 90 of them were analyzed in detail, the X-ray examinations being done at this hospital. In 82 patients arthroscopy gave correct information. In eight (9 per cent) the diagnosis was incorrect, in most cases a rupture of the posterior horn of the medial meniscus being overlooked. Arthrography gave accurate preoperative information in 52 patients, but in 38 (42 per cent) the diagnosis was inaccurate. This difference in correlation with the operation findings between arthroscopy and arthrography was highly significant (P less than 0.001), and it is concluded that endoscopy gives more complete and more useful preoperative information than arthrography. Arthrography, however, remains a valuable diagnostic tool, as arthroscopy cannot be performed in every patient with knee symptoms.

Severe mental retardation in a Swedish county. II. Etiologic and pathogenetic aspects of children born 1959--1970

In an unselected series of 122 children born in 1959--1970 with severe mental retardation (SMR), the magnitude and distribution of the different etiologic and pathogenetic factors were analysed. Prenatal causes were considered relevant in 73 per cent, perinatal in 10 and postnatal in 3. In 12 per cent no traceable cause whatsoever was found. Infantile primary psychoses constituted 2 per cent. Within the prenatal group, no less than 43 per cent presented firm evidence favouring a genetic etiology, chromosomal syndromes together constituting 36 per cent and mutant gene disorders 7 per cent. Etiologically unclassifiable cases with prenatal stigmata and congenital defects amounted to 18 per cent. A condition of fetal deprivation of supply was considered to have been of major importance in 8 per cent. Almost half of the cases had one or more associated CNS handicaps. Cerebral palsy syndromes were evident in 18 per cent and epilepsies in 30 per cent. The relative risk of having cerebral palsy in addition to SMR was strongly correlated to cases classified as prenatally or perinatally acquired CNS syndromes. It is concluded that prenatal prevention is of special importance for reducing the occurrence of SMR. As chromosomal aberrations are the cause in more than 1/3 of cases with SMR, the desirability of developing effective cytogenetic screening methods and programs applicable to all pregnant women is particularly emphasized.

Severe mental retardation in a Swedish county. I. Epidemiology, gestational age, birth weight and associated CNS handicaps in children born 1959--70

In a unselected series of children born in 1959--70 with severe mental retardation (MR)---defined as IQ less than 50---in a Swedish county, the incidence, prevalence, gestational length, birth weight and associated CNS handicaps were analysed. The cumulative incidence at 1-16 years of age was calculated at 3.3% and the prevalence at 11-16 years at 2.8%. These figures were lower than in most other previous studies. In the great majority of cases the pathogenesis was of prenatal origin. The mean gestational lengths and birth weights were decreased compared with those of an average Swedish population. Severe MR affected large and small for date babies more often than could be expected. On the other hand, babies, with a low birth weight, appropriate for gestational age, and with an uncomplicated history, were found not to run a special risk of severe MR. Among the 122 children, 42% had one or more associated CNS handicaps---epilepsy (30%) and cerebral palsy (18%) being the most common.

Arthroscopy in acute injuries of the knee joint

Arthroscopy was performed during the acute phase of injury in 84 knees (79 patients). A satisfactory view of the joint was obtained in all cases, and no complications occurred. About two-thirds of the patients had injuries associated with violent rotation-abduction. In about one-third of the patients operation could be avoided. In cases with haemarthrosis, serious ligament injury was present in nearly 50 per cent. Complete arthroscopy was associated with few diagnostic errors. Clinical examination often led to uncertain or incorrect diagnosis even when performed under anaesthesia by experienced surgeons. In contrast, arthroscopy led to rapid diagnosis and treatment, thus shortening the period of disability. We recommend arthroscopy in acute knee injuries, but the examination must be performed by an experienced arthroscopist.

The changing panorama of cerebral palsy in Sweden 1954-1970. III. The importance of foetal deprivation of supply

From record data derived from an unselected series of 560 Swedish cases of cerebral palsy, born in 1954-70, the significance of prenatal factors associated with materno-foetal vascular insufficiency causing foetal deprivation of supply (FDS) was investigated. Cerebral palsied children were found to have, on an average, retarded intrauterine growth when compared with a normal population. The incidence of bleeding during pregnancy, maternal toxaemia and multiple pregnancies were significantly increased (p less than 0.001). The incidence of the prenatal factors in question had remained unchanged through the years 1954-70. An additive interplay between factors of FDS and asphyxia/cerebral haemorrhage was revealed. As a whole the findings support the conclusion that FDS plays a major role in the pathogenesis of cerebral palsy today, particularly among the multihandicapped.

The changing panorama of cerebral palsy in Sweden 1954-1970. I. Analysis of the general changes

From an unselected series of 560 cases of cerebral palsy in Sweden, born 1954-70, the changes in incidence through the four periods 1954-58, 1959-62, 1963-66 and 1967-70 were analyzed. The total incidence successively and significantly decreased from 2.2% in the first period to 1.3% in the last. This decrease was mainly related to (1) the syndromes of spastic and ataxic diplegia, (2) the low birth weight babies, and (3) the group with perinatal causes. The decrease was not related to any special intelligence quotient or geographical region.

The changing panorama of cerebral palsy in Sweden 1954-1970. II. Analysis of the various syndromes

From an unselected series of 560 Swedish cases of cerebral palsy, born 1954-1970, various data of etiologic and pathogenetic interest were analyzed in detail. Untraceable and prenatal factors were found to dominate within the group of spastic hemiplegia. Placental dysfunction in small-for-date babies and severe asphyxia were thought to be the two main pathogenetic factors among the patients with spastic tetraplegia. In spite of a significant decrease in the number of low birth weight children within the group of spastic diplegia, this syndrome was still very characteristic for the child born immature. Ataxic diplegic forms were found to have greater pathogenic similarities to spastic diplegia than to simple ataxia. In two-thirds of the children the latter syndrome was characterized by normal pregnancy, delivery and birth weight and an untraceable (genetic?) factor. Dyskinetic syndromes were mostly encountered after perinatal asphyxia.