The brain lesions of Cerebral Palsy (CP) occur from the foetal or neonatal period to up to age 2 years. Although the injury to the brain occurs prior to this, a definitive diagnosis of CP may not be made until after that time. This may be because the clinical picture may not be clear for some time and potentially allows exclusion of progressive diseases. In addition, some children have been diagnosed with CP at an early age only to have the symptoms resolve later.
The diagnosis of cerebral palsy is made on the basis of:
- History:
History of a complicated delivery with clear evidence of birth injury or of low-birth weight increases the probability of CP.
- Examination:
A complete neurological examination assessing muscle tone, posture, reflexes and motor milestone are crucial to making a definitive diagnosis of CP and also indicate the type of CP.
- Exclusion of other disorders:
It is important to differentiate between cerebral palsy and other neurological disorders such as tumours, degenerative brain disorders and diseases of the spinal cord and neuromuscular disorders.
- A Magnetic Resonance Imaging (MRI) examination can often assist as it shows the brain structure with any abnormalities.
- Additional specialised investigations may be done if there is suspicion of specific conditions.
- Nerve conduction studies are helpful when a muscle or nerve disorder is suspected.
- Blood tests may for instance determine abnormal thyroid function that can cause abnormalities in muscle tone or deep tendon reflexes or to movement disorders. Chromosome analysis can rule out a genetic syndrome. Biochemical tests are useful to screen for hereditary metabolic conditions that result in accumulation of poisonous chemicals to the brain.
Additional testing may be necessary to evaluate associated conditions. An Electroencephalogram (EEG) is important to evaluate seizure disorders if they are present.
