Table of Contents
[Note: See also "Neuron Energy and Its Psychomotor Manifestations (1898)."]
THE CLASSIFICATION OF NERVOUS AND MENTAL DISEASES
IN reviewing the different forms of nervous and mental diseases we may classify them into organic and functional. By organic affections we mean pathological modifications of the nerve-cell and its processes taking place in the very structure of the cell. The modifications are of a degenerative character, ending in the death of the neuron. Under this category come such diseases as general paresis, dementia praecox, and mental affections of a degenerative structural character. Such diseases may be termed organopathies or necropathies. The functional affections may in turn be divided into neuropathies and psychopathies.
There are mental maladies in which the neuron undergoes degenerative changes which at first bring about an apparent increase and then a suspension of function not necessarily terminating in the destruction of the neuron. The neuron recovers either temporarily or permanently. Such affections are produced by poisons, alcohol, morphine, chloral hydrate, cannabis indica, and other toxic agencies. To this category also belong all mental affections caused by toxic products formed in the organism and slowly and imperfectly eliminated from the body. Here belong all the temporary maniacal, melancholic, and delusional states, such as puerperal mania, epileptic insanity, the insanity of the adolescent and climacteric periods, as well as that of folie circulaire, periodic insanity, alternating insanity, and, in general, all the mental states known at present under the description of manic-depressive insanity. All such neuron affections may be termed neuropathies.
Where the affection depends not so much on the neuron itself, but on the association of neurons, the disease may be described as a psychopathy. In this form of mental affection the neuron itself may remain healthy, the trouble being due to associations with systems of neurons which are usually not called into action by the function of that particular neuron or system of neurons. Such conditions are well known in physiology. Thus in the experiments of Pavlow and his school the flow of saliva in the dog could be brought about by association with a blue light or with a whistle or with the ring of a bell.
What holds true in the case of saliva holds true, for instance, in the case of nausea and vomiting. Stimuli which are ordinarily indifferent may, by association, bring about such conditions. The fault does not lie here in the stimulus, or in the sensation, or in perception, but in the association with reactions of neuron systems with which that stimulus and its percept have become associated. In other words, the fault is of a purely associative character.
Ordinarily only food or gustatory sensations and perceptions of food can call out the flow of saliva or induce nausea and vomiting. Colored light cannot do it. Under special condition of association, however, colored light may call forth the reactions of flow of saliva or of nausea and vomiting, instance the experiments carried on by Pavlow and his pupils.
Emotions are specially subject to such associations of what may be regarded as morbid or pathological in character. Emotions with their physiological effects may be linked by the process of association with any ideas, percepts, and sensations. Sometimes the physiological effects of emotions, or in fact any physiological effects, may be linked by special associative processes with ideas, percepts, and sensations which ordinarily are either indifferent in character to give rise to reactions and physiological effects of a different and even opposite type. Milk may excite nausea, a rose induce disgust, while the croak of a frog or the cawing of a crow may bring about ecstasy; Limburger cheese and overripened game may be enjoyed with intense delight. What association of sense and reaction made the Greeks regard the grass hopper as highly musical? The reactions of muscle and gland are like so many bells which by various connections and combinations may be made to ring from any sensory button.
An object, however harmless, may awaken intense fear while a dangerous object may be passed by with indifference. A man may be afraid of pointed sticks for instance and handle carelessly a revolver. The emotion of fear is associated with the one object, but is dissociated from the other. It is such associations and dissociations that give rise to the mental diseases of a psychopathic character.
This holds true not only of man, but also of the psychic life of the lower animals. My horse is not afraid of automobiles, regards with suspicion camels, and is somewhat startled at the sight of an elephant, yet passes them by; but he gets scared at a piece of paper. Psychopathies, then, may be regarded as essentially pathological affections of associative life. Mental diseases may thus provisionally and roughly be classified into organopathies, neuropathies, and psychopathies.
If the psychomotor manifestations of the pathological process of neuron disaggregation and neuron degeneration be formed into a series, then the first stages of that series of that process constitute the phenomena of functional psychosis or of psychopathy. The stages are concomitant with the pathological conditions in which only the associations, the interrelations of neuron systems, are affected by dissociations;—the neurons, the dissociated aggregates, themselves remain unaffected.
The whole domain of the subconscious belongs to these stages of disaggregation in the course of the pathological process, e.g., the phenomena of hypnosis, of somnambulism, of motor and sensory automatism, of the so-called hysterical sensori-motor disturbances of various organs, over the functions of which the personal consciousness is found on examination to have lost control by reason of neuron disaggregation and dissociation. Here belong the phenomena of double and multiple personality, the various phenomena of amnesia, the lost content of which can be revealed in the strata of subconscious life.
The domain of functional psychosis or of psychopathy also includes the phenomena of the different forms of so-called "psychic epilepsy." Here also belongs the great class of psychomotor derangements, such as phobias, impulsions, obsessions, fixed ideas, and allied states.
The phenomena of functional psychosis are coextensive with the whole domain of the subconscious. Functional psychic disturbances, or psychopathies are correlated not with organic, structural neuron degeneraon, but with disaggregation of functioning systems or of neuron aggregates. The he physiological cause is the rise of thresholds of the intercommunicating neuron systems.
In psychopathic affections the function apparently lost and destroyed is found to be present in the subconscious,—the loss of function is only for the direct personal consciousness. The affection is only of a dissociative character. The activity of the affected system is itself sound; in fact, is often found to be exaggerated,—the system is only dissociated from other functioning systems.
The total energy of the neuron may be classified into dynamic energy, reserve energy, static energy, and organic energy.
The psychopathies, neuropathies, and organopathies or necropathies may be correlated with the flow and ebb of neuron energy, with the physiological and pathological processes that take place in the neuron in the course of its activity. This may be represented by the diagram on page 101.
By dynamic energy of the neuron is meant that part of energy which the neuron as an individual organism can dispose of in its relations to other neurons forming complex functioning organizations.
The dynamic energy is represented by the upper portion of the parallelogram A M L K.
By reserve energy is meant that surplus amount of dynamic energy which is kept in reserve and drawn upon by the organism under special conditions and emergencies.
Reserve energy is indicated by the diagram K N W A
By static energy is designated that portion of energy that is used only for the life maintenance of the neuron, both in relation to other neurons and to its own inner molecular constitution. Static energy cannot be drawn upon by the neuron in its functioning activity with other neurons without bringing about a state of disintegration.
Static energy is indicated by the diagram N W F I.
By organic energy is meant that energy contained in the very structure of the tissues of the neuron, not as yet decomposed into their inorganic constituents. This is indicated by diagram I F G H.
These phases of neuron energy are not different kinds of energy, in the sense of being distinct entities; they merely represent progressive phases or stages of the same process of neuron activity.
Liberation of neuron energy is correlative with active psychic and physical manifestations. Hence states of the nervous system corresponding to liberations of energy are designated as waking states. Restitution of expended energy or arrest of liberation of neuron energy goes hand in hand with passive conditions of the nervous system; hence states of restitution or arrest of energy are termed collectively sleeping states.
In the diagram this correlation is followed out in the direction of the arrows. The arrow, indicating successive levels of liberation of energy, corresponds to a similar arrow which indicates the course and progress of the waking states running parallel to the process of liberation of energy. The arrows at the top of the diagram illustrate the physiological and pathological processes at work in the cycles of expenditure and restitution of energy, while the bottom of the diagram indicates by its arrows the concomitant psychomotor manifestations—the waking and sleeping states.
The ascending arrow, indicating the process of restitution of energy, corresponds to the ascending arrow indicating the parallel psychomotor sleeping states. The descending arrows indicate physiological and pathological processes of liberation of energy, and also their concomitant psychomotor waking states.
“Ascending” and “descending” mean the rise and fall of the amount of neuron energy, taking the upper level of dynamic energy as the starting point. Briefly stated, descent means liberation of energy with its concomitant psychomotor waking states. Ascent means restitution of energy with its parallel sleeping states.
The cycles in dynamic energy correspond to the physiological manifestations of the nervous system in the activity and rest of the individual in normal daily life. Concomitant with the expenditure of dynamic energy of the neurons, the individual passes through the active normal waking state, and, hand in hand with the restitution of this expended dynamic energy, he passes through the sleeping state of normal daily life.
When, however, in the expenditure of energy, the border line or margin, A K or N W, is crossed, dynamic and reserve energies are used up, and reserve and static energy are drawn upon. In crossing A K or N W the border line that separates the normal physiological from the abnormal or pathological psychomotor manifestations is stepped over.
“The thresholds of our psychological systems are usually raised, mental activity working in the course of its development and growth of associative processes under ever-increasing inhibitions with ever higher thresholds. . . . On account of the high thresholds and inhibitions, not the whole amount of the psycho-physiological energy possessed by the system is manifested; in fact, but a very small portion is displayed in response to stimuli coming from the habitual environment. What becomes of the rest of the unused energy? It is stored, reserve energy.
“Biologically regarded, we can well see the importance of such stored or reserve energy. In the struggle for existence the organism whose energies are economically used and well guarded against waste will meet with better success in the process of survival of the fittest or will have better chances in the process of natural selection. The high thresholds and inhibitions will prevent hasty and harmful reactions, useless waste of energy, unnecessary fatigue, and states of helpless exhaustion. Moreover, natural selection will favor organisms with greater stores of reserve energy, which could be put forth under critical conditions of life. In fact, the higher the organization of the individual, the more varied and complex the external environment, the more valuable and even indispensable will such a store of reserve energy prove to be.”
Static energy may be divided into two phases according to the nature of the process of liberation of neuron energy. As long as the process of liberation of energy effects only a dissociation of systems of neurons the correlative psychomotor manifestations fall under the category of psychopathies. If, however, the process of liberation affects the neuron itself, bringing about a disintegration of its constituent parts compatible with restitution, the correlative psychomotor manifestations fall under the category of neuropathies. This process of disintegration, equivalent to cell degeneration may end in death, in the dissolution of the neuron itself.
By psychopathies, then, is designated the pathological phenomena of psychic disaggregation correlative with the state or processes of dissociation within clusters or constellations of neurons, the neuron itself remaining undamaged.
By neuropathies is indicated a group of psychophysical manifestations running parallel to fluctuations of static energy and accompanied by functional and organic changes in the neuron.
By organopathies or necropathies is indicated a group of psychophysical manifestations running parallel with fluctuations of organic energies and accompanied by structural changes or by necrotic modifications resulting in the ultimate death of the neuron system.
The usual classification of mental functions is into: intellect, feeling, and will. By intellect is understood such functions as perception, conception, memory, abstraction, imagination and judgment. Under feeling are ranged sensations, pleasures, pains, moods, affective states and emotions. By will is meant all the functions leading towards action, our conations, desires, strivings, tendencies, and decisions. If we accept this psychological classification, we may accordingly classify mental diseases.
From our standpoint we need not go into the details of psychological classification. What we wish is to classify the nervous and mental derangements that fall into the domain of psychopathology.
We may take the physiological reflex arc as our basis of classification, namely the passage of a nerve current from a sense-organ through a sensory nerve to an intermediary central neuron or ganglion, and thence through a motor nerve to muscle; we can conveniently classify all psycho-physiological functions into sensory, intermediary or ideational, and motor. Biologically this classification is well justified inasmuch as by means of the sensory function the animal receives impressions from the external environment, elaborates them in the centre, and then reacts by motor adjustments and adaptations.
Psychopathic states are classified into sensory disturbances of sense organs and viscera, the various forms of anaesthesia; motor disturbances, and finally derangements of ideas, memory, will, and emotion. We give here a brief clinical description of various forms of psychopathic states in the ascending scale of their development, complexity, and organization, beginning with sense-disturbances known as the anaesthesias.
According to the symptoms we may divide psychopathic maladies into:
Under the peripheral may be classed the following:
(1) Sensory disturbances, the anaesthesias.
(2) Motor disturbances, derangements of motor adustments and epileptoid attacks.
(3) Visceral disturbances, glandural affections, secretory, respiratory, cardiac, intestinal and sexual derangements.
Under periphero-central we may class:
(2) Hallucinations, pseudo-hallucinations, the dream-hallucination, hypnotic hallucination, the aphasias.
Under central disturbances we may class:
(1) Delusions, the various forms of amnesia, aboulia, fixed ideas, morbid impulses, emotions, and morbid propensities.
We shall follow this order in our account of the various psychopathic maladies.