AETIOLOGY OF ATHETOSIS WITH SPECIAL REFERENCE TO NEONATAL ASPHYXIA, IDIOPATHIC ICTERUS, AND ABO-INCOMPATIBILITY

Functional outcomes of children with dyskinetic cerebral palsy depend on etiology and gestational age

OBJECTIVE

To elucidate the differences in etiology of dyskinetic cerebral palsy (DCP) between term-born and preterm-born children and its relationship to functional outcomes.

METHODS

We determined the etiology of DCP based on the clinical course and brain MRI of 163 term-born and 136 preterm-born children. Information about genetic abnormality was also collected if available. Functional outcomes were compared between the two major etiologies in each group, i.e., hypoxic ischemic encephalopathy (HIE) and bilirubin encephalopathy (BE), using four standardized classification systems, i.e., Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), Communication Function Classification System (CFCS), and Eating and Drinking Ability Classification System (EDACS).

RESULTS

The most common etiologies were HIE (123/163) in term-born and BE (93/136) in preterm-born children. Genetic mutations were identified in 14 of 30 term-born children with no other known etiology. GMFCS levels of the preterm children with BE were significantly poorer than those of term children with HIE (p < 0.01). Both the CFCS and EDACS levels were significantly better in preterm children with BE than in term children with HIE (p < 0.01).

CONCLUSION

The most common etiology of DCP is different between term-born and preterm-born children, and the distribution of functional impairment is significantly influenced by etiology and gestational age. The difference should be taken into consideration to allow the provision of adequate interventions.

Deep hypothermia prevents striatal alterations produced by perinatal asphyxia: Implications for the prevention of dyskinesia and psychosis

GABAergic medium spiny neurons are the main neuronal population in the striatum. Calbindin is preferentially expressed in medium spiny neurons involved in the indirect pathway. The aim of the present work is to analyze the effect of perinatal asphyxia on different subpopulations of GABAergic neurons in the striatum and to assess the outcome of deep therapeutic hypothermia. The uterus of pregnant rats was removed by cesarean section and the fetuses were exposed to hypoxia by immersion in water (19 min) at 37°C (perinatal asphyxia). The hypothermic group was exposed to 10°C during 30 min after perinatal asphyxia. The rats were euthanized at the age of one month (adolescent/adult rats), their brains were dissected out and coronal sections were immunolabeled for calbindin, calretinin, NeuN, and reelin. Reelin+ cells showed no staining in the striatum besides subventricular zone. The perinatal asphyxia (PA) group showed a significant decrease in calbindin neurons and a paradoxical increase in neurons estimated by NeuN staining. Moreover, calretinin+ cells, a specific subpopulation of GABAergic neurons, showed an increase caused by PA. Deep hypothermia reversed most of these alterations probably by protecting calbindin neurons. Similarly, there was a reduction of the diameter of the anterior commissure produced by the asphyxia that was prevented by hypothermic treatment.

Early Controversies over Athetosis: I. Clinical Features, Differentiation from other Movement Disorders, Associated Conditions, and Pathology

BACKGROUND

Since the description of athetosis in 1871 by American neurologist William Alexander Hammond (1828-1900) the disorder has been a source of controversy, as were many aspects of Hammond's career.

METHODS

Primary sources have been used to review controversies in the 50-year period since the initial description of athetosis, in particular those concerning clinical features, differentiation from other movement disorders, associated conditions, and pathology. Controversies concerning treatment will be addressed in a subsequent article.

RESULTS

Hammond struggled to establish athetosis as a distinct clinical-pathological entity, and had successfully predicted the striatal pathology in his initial case (albeit somewhat serendipitously). Athetosis was, nevertheless, considered by many neurologists to be a form of post-hemiplegic chorea or part of a continuum between chorea and dystonia. European neurologists, and particularly the French, initially ignored or discounted the concept. Additional controversies arose over whether the movements persisted during sleep, whether athetosis was, or could be, associated with imbecility or insanity, and how it should be treated.

DISCUSSION

Some controversies concerning athetosis served to identify areas where knowledge was insufficient to make accurate statements, despite prior self-assured or even dogmatic statements to the contrary. Other controversies illustrated established prejudices, even if these biases were often only apparent with the greater detachment of hindsight.

Birth-related syndromes of athetosis and kernicterus

"Athetosis," from the Greek athetos, meaning "without fixed position," is a movement disorder first described by Hammond in 1871. The term described slow, irregular continual movements of the distal extremities. In 1983, Foley defined the athetoid syndrome as "a nonprogressive but evolving disorder due to damage to the basal ganglia of the full-term brain … [with] impairment of postural reflexes, arrhythmical involuntary movements, and dysarthria, [but] sparing … sensation, ocular movements and … intelligence." A decade later, "athetoid syndrome" was replaced by "dyskinetic cerebral palsy." Injury to basal ganglia by various mechanisms, including asphyxia, trauma, perinatal strokes, and kernicterus, is known to cause birth-related athetosis. Kernicterus originally described the neuropathology of bilirubin-induced brain injury, where the deep nuclei of the brain stain yellow. Kernicterus now describes the clinical features of chronic bilirubin encephalopathy, which include an extrapyramidal movement disorder, sensorineural hearing loss, impaired upward gaze, and dental enamel dysplasia. Aggressive treatment of perinatal hyperbilirubinemia has led to a decline in kernicterus so that, today, it is a rare cause of dyskinetic cerebral palsy. In this chapter, we provide a historic overview of athetosis and its formerly common cause, kernicterus. We relate earlier terminology to more recent definitions of impairments in dyskinetic cerebral palsy, including dystonia, chorea, and choreoathetosis.

Dyskinetic cerebral palsy. II. Pathogenetic risk factors and intra-uterine growth

In an unselected series of 116 dyskinetic cerebral palsy cases, 35 hyperkinetic and 81 dystonic, 21% of the cases were considered to derive from the prenatal period, 67% from the perinatal, and 7% from the postnatal period, while 5% were untraceable. Isolated risk factors were found in 24% of the hyperkinetic and 24% of the dystonic cases and various combinations in 68% and 72%, respectively. Preterm appropriate-for-gestational-age cases with hyperbilirubinemia were found significantly more often among the hyperkinetics (47%) than among the dystonics (11%). Term appropriate-for-gestational-age cases with asphyxia were found significantly more often among the dystonics (30%) than among the hyperkinetics (9%). Term and preterm small-for-gestational-age cases with asphyxia and/or perinatal hypoxia were only found in the dystonic subgroup (14%). Both the hyperkinetic and the dystonic subgroups had significantly lower mean birth weights--2795 g and 2872 g, respectively--than that of the general population, 3500 g. The dystonic subgroup had birth weights significantly below the mean for gestational age. Both subgroups had birth weights significantly below the mean for the respectively birth length. This was particularly pronounced for the cases with birth asphyxia. All infants with birth weights less than or equal to -2.0 SD below the mean for birth length had had birth asphyxia, and the proportion decreased successively to 0% among those greater than +1.0 SD.

Dyskinetic cerebral palsy. I. Clinical categories, associated neurological abnormalities and incidences

An unselected series of 116 dyskinetic cerebral palsy cases born 1959-70 was delineated and subgrouped according to neurological criteria into 35 hyperkinetic (30%) and 81 dystonic (70%) cases. Of the hyperkinetics, 80% had a mild motor disability, while 90% of the dystonics had moderate or severe disability. Subordinated spastic signs were found in 9% of the hyperkinetic and in 44% of the dystonic cases. IQ was greater than 90 in 69% of the hyperkinetics and 25% of the dystonics and less than 50 in 11% and 41%, respectively. Two or more additional neurological abnormalities (spasticity, mental retardation, epilepsy, anarthria, dysarthria, hearing deficit) were detected in 46% hyperkinetic and 81% dystonic cases. A heavy multihandicap complex was present predominantly in the dystonic subgroup. The 5-19 year mortality rate was 6% and was confined to the most severely handicapped dystonic cases. The twin rate was 5%. A total of 9% had birth weights less than or equal to 1500 g, and 31% had less than or equal to 2500 g. The weight- and age-specific incidences increased rapidly with decreasing birth weights and gestational ages. The crude incidence of hyperkinetic cerebral palsy was 0.07 and dystonic cerebral palsy 0.17 per thousand live births.

The neurology of cerebral palsy

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