Both nodding epilepsy and epilepsia procursiva appear to be rare. Personally I have never seen any- cases.
Alterations in the psychic functions, in the form of either abolition or impairment of consciousness, or of a change in the individual's ehar acter, are practicallyt constant accompaniments of the motor discharge. In addition, it has been known since the time of Esquirol that there may be paroxysmal psychic disturbances ("psychische equivalente," Hoffmann) which occur .spontaneously and may alternate with the motor attacks. Typical examples of this psychic epilepsy are seen in the aura, (compare page 361), in ambulatory automatism, and certain psychotic conditions of short duration with maniacal excitement or depression. What has been already said in connection with epileptic aurce applies to all phenomena of this kind. They are nmeh more rare in childhood than after puberty, and appear to occur only in genuine epilepsy. They are characterized by their sudden onset and disappear ance, and by the utter failure to remember anything that occurred or that the patient has clone during the time of the attack, which is in great contrast to the inclividual's behavior during the pyschotic change, which is often quite deliberate and orderly.
During the intervals of freedom many epileptic children exhibit eerebral—motor and psychic—disturbances which are termed collectively, intraparoxysmal symptoms. They are of considerable interest because they prove that epilepsy is a chronic, diffuse disease of the brain, but they have little diagnostic value because they develop comparatively late.
In our description of eclampsia infantum, we learned that mechanical and galvanic overexcitability of the peripheral nervous system is a necessary interparoxysmal symptom of the highest diagnostic im portance, which is present from the beginning of the disease. The interparoxyanial symptoms of epilepsy.are of a totally different nature. They are not latent symptoms of an abnormal condition of irritability which it is possible to discover by examining the patient, but rather afford clinical eviclence that the epilepsy, or some other similar change in the brain has attained a considerable extent. In the main, therefore,
they resemble the postparoxysmal symptoms of bodily and mental fatigue and exhaustion, and exhibit every grade of intensity. Lasting change.s in the individual's character gradually develop. They may become ill-natured, silly, violent, quarrelsome, etc., and the intelligence may suffer to the point of pronounced epileptic idiocy.
These interparoxysmal symptoms develop gradually after the dis ease has lasted for a variable length of time, i.e., when the periodical recurrence of the attacks has already established the diagnosis. They are of no assistance in interpreting the early, ambiguous attacks.
The cerebral symptoms of idiocy, infantile palsies, and the like, which precede or accompany epilepsy, or remain as permanent sequels of severe attacks, such, for example, as scars on the tongue, cutaneous haimorrhage and the like, do not properly belong to this category.
In the etiology of epilepsy heredity plays an important part, particularly direct homologous inheritance. Sometimes the disease skips a generation so that, for example, epileptic children may have a healthy father and an epileptic grandfather. Inheritance from both parents, however, is only found in a small percentage of epileptic eases and, according to Marie's investigation, is much less frequent as an etiologic factor than some infectious disease. -Without going into the numerous and contradictory statistics, we may say this much, that the frequency of inheritance from both parents is notieeable only in genuine epilepsy, beginning shortly- before or at the time of puberty; while in symptomatic epilepsy it is of slight importance. In the latter variety of the disease, transforming inheritance and a general neuropathic taint, play a much more important, but at the same time unintelligible role, so that other etiologic faetors appear to be more weighty. Among the latter are infra- or extra-uterinc diseases of an infeetious or toxic nature and, as exciting factors, physical and psychic injuries (fright).