Quando sospettare una patologia metabolico-degenerativa: Apporto della neurofisiologia

Neurophysiological studies are important diagnostic tools for suspecting and early diagnosing metabolic and degenerative disorders of childhood. They can give useful information on the basis of the so called 'selective vulnerability' of central nervous system. In fact it is possible to identify a selective involvement of grey matter or white matter, either isolated or associated with peripheral, visual and/or auditory impairment. In some grey matter diseases, such as neuronal ceroid lipofuscinoses, EEG and multimodal evoked potentials are specific for each subtype and vary during the course of the disorder. In white matter diseases, the nervous conduction velocity can demonstrate an associated involvement of the peripheral myelin, thus suggesting a limited number of diseases. Suggestive or even specific electrophysiological patterns may constitute an important indication for the correct diagnosis of neurometabolic diseases of childhood, if related to clinical signs and symptoms.