How quickly can we diagnose cerebral palsy disorders? Medical experts agree unanimously that early diagnosis allows for earlier interventions, leading in turn to greater improvements in functional ability, muscle development and coordination.
Identifying children with cerebral palsy, however, can be difficult during their earliest years, especially where less-severe forms of the disorder are concerned. As a result, most diagnoses are only confirmed after a child has reached the age of two or three, according to the American Pregnancy Association.
3 Tests To Diagnose Cerebral Palsy Before 5 Months
A new study published in the Journal of the American Medical Association (JAMA) says we could be doing a lot better. In their article, an international team of child development specialists (who represent 28 prestigious medical institutions) suggest that the clinical signs of cerebral palsy disorders emerge long before a child reaches the age of two, a fact that should allow medical professionals to make accurate early diagnoses.
How? The researchers identify a trio of diagnostic tests that clinical evidence has shown to be remarkably precise in diagnosing cerebral palsy disorders before five months of age. Combing through the results of six systematic reviews, which analyze the findings of multiple studies, and two well-supported clinical guidelines, the team of pediatricians and cerebral palsy experts highlighted the astounding accuracy of magnetic resonance imaging (MRI), the Prechtl Qualitative Assessment of General Movements and the Hammersmith Infant Neurological Examination.
Magnetic Resonance Imaging
Magnetic resonance imaging, or MRI, uses strong magnets to realign the atomic nuclei inside the body. The technique produces wonderfully-detailed images of internal body structures, including the brain. MRI is crucial in identifying brain damage, including brain damage caused by prenatal oxygen deprivation, a primary cause of cerebral palsy.
86% – 89% Sensitivity
The JAMA study suggests that MRI tests administered within the first five months of a child’s life are between 86% and 89% successful in identifying children with cerebral palsy disorders.
Prechtl Qualitative Assessment Of General Movements
Designed by Austrian developmental neurologist Heinz Prechtl, the Qualitative Assessment of General Movements is a form of visual analysis, conducted by specialists, that can identify children with cerebral palsy disorders with unprecedented precision.
Dr. Prechtl’s great insight was that infants who are born without brain injuries move in fairly predictable ways. These movements are reflexive and complex, but share certain qualitative features that a trained analyst can identify. Children born with brain damage, and specifically cerebral palsy disorders, on the other hand, conform to a different set of movement patterns. As it turns out, noticing the qualitative differences between these movement patterns is a remarkably effective, and non-invasive, way to accurately diagnose cerebral palsy.
Prechtl’s Assessment of General Movements, according to the recent JAMA study, is even better at diagnosing cerebral palsy than MRI. In their analysis of published research, the team of developmental specialists found that examinations conducted in accordance with Prechtl’s insights accurately identify infants with cerebral palsy 98% of the time.
How does it work? In essence, specialists observe an infant’s spontaneous movements, either in person or using pre-recorded videos. Conducting the Prechtl Assessment correctly requires a fair deal of training. Many hospitals now offer courses in the identification of General Movements (a specific form of spontaneous movement), teaching practitioners to accurately distinguish between the General Movements of healthy infants and those made by children born with brain injuries.
Hammersmith Infant Neurological Evaluation
Created to evaluate children between 2 and 24 months, the Hammersmith Infant Neurological Evaluation is a clinical test that assesses the muscle tone, reflexes, posture and reactions of infants. Like the Prechtl Assessment, the Hammersmith Evaluation takes into account the quality of a child’s movements, but also gauges their quantity – how often a child moves. The Hammersmith method is a little more invasive than Prechtl’s technique. Practitioners actually manipulate a child’s body, in order to evaluate their reflexes, along with the minute movements made to maintain posture. Needless to say, trained specialists will conduct the test gently, without risking a child’s health or comfort.
In their analysis of previous studies, the study authors found that Hammersmith’s diagnostic criteria are able to diagnose children with cerebral palsy disorders in 90% of cases.
The Hammersmith Evaluation, however, is even more powerful than that. An aggregate score, found by adding up a child’s scores from 26 discrete examinations, can accurately predict the development of a cerebral palsy disorder in most cases. Moreover, each of the 26 discrete tests can make reliable predictions about how, specifically, a child’s disorder will come to affect their motor abilities over time. In other words, the Hammersmith method makes both general and specific predictions, both quite accurate.
A Note On “Sensitivity”
In the field of statistics, sensitivity refers to the amount of “true positives” turned up by any given diagnostic method. In other words, a more-sensitive diagnostic technique gets more diagnoses right than less-sensitive techniques. For our purposes, sensitivity refers to the proportion of people who actually have cerebral palsy that these diagnostic methods accurately identify.
With that basic understanding in hand, it becomes clear that MRI, the Prechtl Assessment and the Hammersmith Examination are remarkably sensitive, and thus remarkably effective, in diagnosing cerebral palsy disorders before the age of five months. Their accuracy becomes even more astounding when you consider that most children with cerebral palsy disorders are only conclusively diagnosed after reaching the age two.