The diagnosis remains essentially a clinical one, based on symptoms and signs of the individual's Nervous System malfunction. A symptom is something that is reported by the patient. A sign is an abnormality detected by the physican while examining the person. At times signs confirm the presence of symptoms. Some abnormal reflexes or loss of Vibratory Sense may be present without the patient being aware of anything being wrong.
Symptoms are subjective complaints, whereas signs are objective observations.
It is important to realize this, so that the appearance of a new symptom does not necessarily signify the formation of a new lesion . It is difficult to understand how lesions that are discovered at autopsy have not produced symptoms in view of their location and size, but they are seen repeatedly.