Chemistry is the foundation of life, which is why biochemical or metabolic errors are of great significance. The range of biochemical and metabolic tests available can be overwhelming.
At our Paediatric and Neurology Clinic, we strive to consider all clinical aspects of a child and develop a personalised diagnostic plan rather than follow a generic ‘screening’ approach.
A tailored biochemical and neurometabolic investigations may detect disorders reversible by specific therapy, or sometimes irreversible disorders of great family significance.
When dealing with neurometabolic disorders, it can be challenging to decide whether to conduct testing or not, especially since many of these conditions are progressive. One crucial factor to consider is whether the disorder is static or progressive. If we are unsure about the answer, it may be necessary to proceed with investigations as if the disorder were progressive.
The followings are a list of common neurometabolic tests which are often used in the diagnosis of neurological disorders in children:
| Urine test | Indications |
|---|---|
|
Urine Organic Acids |
Developmental delay, learning disability, macrocephaly, movement disorders, ’cerebral palsy’, encephalopathy with or without epileptic seizures, myelopathy |
|
Urine Copper |
Movement disorders, behaviour disorder with or without liver dysfunction |
|
Urine Catecholamines |
Acute or subacute cerebellar ataxia, myoclonus, opsoclonus; early onset movement disorder with dystonia and oculogyric crisis; neonatal hypothermia and failure to thrive |
|
Urine GAG (glycosaminoglycans) |
Learning disability, coarse facies, corneal clouding, speech impairment, behavioural impairment. |
| Blood test | Indications |
|---|---|
|
Acylcarnitine/ carnitine profile |
Acute encephalopathy, Acute myopathy, rhabdomyolysis, unexplained hyperCKaemia |
|
Alpha-fetoprotein |
Ataxic ‘CP’, oculomotor apraxia |
|
Amino Acids |
Learning disability, hypotonia, early onset epilepsy, acute encephalopathy, intermittent ataxia, movement disorders, stroke |
|
Ammonia |
Early onset seizures, acute encephalopathy, stroke, vomiting-headache-impaired consciousness complex, ataxia |
|
Caeruloplasmin |
– Movement disorders, behaviour disorder with or without liver dysfunction – hypotonia, seizures, steely hair |
|
Calcium |
– Seizures, learning disability, movement disorders – developmental delay/ elfin facies |
|
Cholesterol |
Developmental delay, retinopathy, deafness, skeletal dysplasia, ataxia, spinocerebellar ataxia |
|
Copper |
– Movement disorders, behaviour disorder with or without liver dysfunction – hypotonia, seizures, steely hair |
|
CK |
Speech delay, toe walking, muscle weakness |
|
Creatinine |
Learning disability, seizures, movement disorders |
|
Electrolytes (Sodium, potassium, bicarbonate) |
Acute illness, intermittent weakness |
|
Ferritin |
Iron deficiency, restless leg syndrome, infection |
|
Glucose |
Reduced level of consciousness, seizures |
|
Lactate |
Encephalopathy, suspected mitochondrial disorders |
|
Magnesium/ Phosphate |
Neonatal seizures |
|
Prolactin |
Movement disorders, unexplained ‘seizures’ |
|
Thyroid function tests/ fT3 |
Thyroid diseases, encephalopathy, movement disorders |
|
Liver function tests |
– Developmental delay, hypotonia – Congenital infection/ congenital infection like disorder – Suspected mitochondrial disorders |
|
Uric Acid |
Early movement disorder with developmental delay |
|
Vitamin A |
Loss of vision in autism |
|
Vitamin B12 |
Developmental delay, seizures, movement disorders |
|
Vitamin E |
Developmental delay, retinal defects, deafness, ataxia |
| CSF test | Indications |
|---|---|
|
Amino acids |
Learning disability, hypotonia, early onset epilepsy, acute encephalopathy, intermittent ataxia, movement disorders, stroke |
|
Glucose |
Epilepsy, developmental delay, ataxia, movement disorders |
|
Lactate |
Suspected mitochondrial disorders |
|
Neurotransmitters |
Movement disorders, suspected inflammatory CNS disorder |
