The search for etiological diagnoses

[Posted on 30 January, 2018 by Ola Skjeldal]

I have been a physician for over 40 years, mostly working as a paediatric neurologist. My main focus in all these years has been children and adolescents with rare medical disorders including different types of neurological syndromes, many of them with co-occurring neuropsychiatric symptoms. Mildly speaking – it is a complicated and challenging area. As of today about 1500 neurometabolic disorders and more than 10 000 neurological syndromes have been described, the majority with a genetic origin. Furthermore, children can be affected by neuromuscular diseases, acquired CNS infections, and different kinds of degenerative disorders. Finding a medical/etiological diagnosis is important in order to provide good treatment. However, colleagues from other disciplines have sometimes asked me why I am a neurologist. “It is difficult to find the etiological diagnosis and you do not have an effective treatment”. This is essentially a half-truth. Compared to some years ago many more patients with different kinds of neurological conditions can be treated, especially within the area of some specific neurometabolic disorders and epilepsy. There has been a marked positive development in treatment strategies. However, I admit that in most paediatric neurological disorders still no effective specific treatment strategy exist. Thus, one of the main tasks within child neurology will be the diagnostic/etiological search for a rare neurological condition.

In the healthcare system there is a long tradition of categorization of diseases and related health problems. Medical disorders can be classified in different ways. They can be divided on the etiological background factors involved or anatomical structure affected. Sometimes diseases are also categorized on the basis of known pathophysiological mechanisms. This classification is currently used in ICD (International Classification of diseases) that has been used internationally since 1900.

Ideally one would wish that all diseases were classified on the basis of etiological factors. As we all know, this is not the situation, especially not within paediatric neurology. However, the search for the etiological diagnosis is still very important, for several reasons.
Correct diagnoses make it possible to plan health services, allocate health resources, monitor the health of the population and carry out preventive work. Proper diagnosis gives the child and parents a rational explanation as to why the child has developed severe neurological symptoms, and in most cases this might be positive for the family. A diagnosis will also provide information on prognosis, which almost all parents ask for when they have a child with a neurological disability. If it is a genetic disorder the doctor will have the opportunity to provide genetic counselling with regard to later pregnancies.

Classification of diagnoses has changed radically since the first edition of the ICD. Our understanding of neurological disorders is totally different compared to some ten years ago. Neuroimaging, neurometabolic tests and not least genetic knowledge have contributed to this and we must prepare for this change to continue. We already see it. New diagnostic tools change our understanding of the diagnostic concept. There will be more than enough challenges for future physicians.

[This is a blog. The purpose of the blog is to provide information and raise awareness concerning important issues. All views and opinions expressed are those of the writer and not necessarily shared by the GNC.]