A model of neurological disorder: a basis for logical and structured thinking and reasoning in neurology

A model of neurological disorder in graphical form, based upon a model proposed by the World Health Organisation, is presented. This model is intended to be a basis for a logical and structured thinking and reasoning in neurology, not least in diagnosis. The model is a chain of basic elements in which each element causes the following one. The chain can be divided in two parts. The first part is: Etiology → Pathology → Manifestation. Pathology is described by the properties of the lesion in the nervous system. Manifestation is the symptoms and signs, that can be summarised as Semiology, in fact, synonymous with Impairment. The second part of the model is then: Manifestation (= Impairment) → Disability → Handicap. The terms disease and disorder are not contained within the chain of basic elements. The manifestation gives the patient an awareness of disorder and the condition may be classified as syndrome or disease. Neither the awareness of disorder nor the classification influences the chain of basic elements.