The 8th chapter of Charaka Samhitha Nidana Sthana is called Apasmara Nidana. It deals with the causes, pathology,types and symptoms of Apasmara – Epilepsy, as per Ayurveda.
We shall now explore the chapter on the Apasmara – Diagnosis of Epilepsy. Thus said Lord Atreya [1-2]
Types of Apasmara (epilepsy):
There are 4 types of epilepsy, viz,
Epilepsy manifests itself quickly in the following types of individuals:
Rajastamobhyaamupahata – When the mind of an individual is overshadowed by Rajas and Tamas
When the Doshas get exceedingly aggravated and their equilibrium is disturbed
When an individual takes food consisting of unclean and unwholesome ingredients possessing mutually contradictory (or touched by the unclean hands of persons suffering from contagious diseases like Leprosy), neglecting the prescribed deictic rules;
When he resorts to unhealthy regimens and behavior and
When he suffers from excessive debility.
In the situations mentioned above, the Doshas get aggravated and attach the persons whose minds are overshadowed by Rajas and Tamas. The Doshas (so aggravated) permeate the heart, organs. While staying there, the Doshas aggravated by force of etc, perturbation etc. all of a sudden, spread throughout the heart and the sense organs. Then an individual fall a victim to epilepsy. 
Definition of Epilepsy:
Epilepsy is characterized by occasional unconsciousness associated with loathsome activities (like vomiting of froth and abnormal postures of the body), due to the perversion of memory, intellect and other psychic faculties. 
Purvarupa (Premonitory symptoms) of Apasmara:
The following are its Purvarupa (premonitory symptoms):-
Contraction of eye- brows
Irregular movement of eyes constantly
Hearing of such sounds as are non- existent
Excessive discharge of saliva and nasal- excreta
Disinclination for food, anorexia and indigestion cardiac spasm
Distension of the lower abdomen with gurgling sound
Weakness, cracking pain in bones and malaise
Unconsciousness, entering into darkness, fainting and giddiness and
Frequent appearance of scenes of intoxication, dancing, murdering, aching, shivering and falling in the dreams
Thereafter the epilepsy is manifested. [6-7]
The following are the characteristic features of different types of epilepsy:
Vataja Apasmara Vishesha Rupa:
Losing and regaining consciousness instantaneously
Projection of eye balls;
Vomiting of frothy matter
Excessive heaviness and rigidity of neck
Bending of the head to one side
Irregularly contacted fingers
Instability of upper and lower limbs
Reddishness, dryness and brownishness of nails, eyes face and skin
Vision (aura) of unstable, fickle, coarse and dry objects
Aggravation of the condition by such regimens as are aggravators of Vata and
Alleviation of the condition by such regimens are alleviations of Vata.
Pittaja Apasmara Vishesha Rupa:
Losing and regaining consciousness instantaneously
Rubbing the earth
Green, yellow or coppery color of nails, eyes, face and skin
Vision (Aura) of bleeding, terrifying(which is also injurious), frightful, burning and angry looking objects
Aggravation of the condition by such regimens as are aggravators of pitta and
Kaphaja Apasmara Vishesha Rupa:
Delay in losing and regaining consciousness
Absence of much distortion of activities
Dribbling of saliva white color of nails, eyes, face and skin
Vision (aura) of white, heavy and unctuous objects
Aggravation of the condition by such regimens as are aggravators of kapha and
Alleviation of the condition by such regimens is alleviators of Kapha.
Sannipatika Apasmara Vishesha Rupa:
Epilepsy of Sannipatika type (caused by the simultaneous vitiation of all the 3 Doshas) shares the symptoms of all the 3 Doshas (described above). This condition is incurable.
Thus the 4 types of epilepsy are explained. 
Extrinsic causative factors:
At times these condition are associated with extrinsic causative factors which will be described later (in Chikitsa 10: 53). Their specific characteristic are the association of additional symptoms which are not manifested due to the various dosha already described. 
Types of treatment:
Strong elimination and alleviation therapies depending upon the specific requirements are useful for patients suffering from epilepsy. When this is associated with extrinsic causative factors, then Mantras etc., will be useful. 
Mythological origin, treatment, prognosis
Mythological origin of diseases, line of treatment and prognosis of epilepsy:
During the destruction of Dakshas’ sacrifice, Gulma first due to the aggravation in their body because of fleeing, swimming running, flying, jumping etc., Pramehas (obstinacy urinary disorders including diabetes) and Kusthas (obstinate skin diseases including leprosy manifested themselves due to intake of ghee, various types of Unmada (insanity) due to fear, apprehension and grief, and Apasmara (epilepsy) due to coming into contact with various types of unclean objects. Fever came out of the forehead of Lord Shiva. Raktapitta (a condition characterized by bleeding from different parts of the body) due to its heart and Rajayaksma (Tuberculosis) occurred in the moon, the king of stars, due to excessive sexual indulgence.
Thus it is said: – epilepsy manifests itself due to the vitiation of Vata, Pitta and Kapha as well as due to Sannipata (combined vitiation of all the 3 Doshas). The last one is incurable. The curable varieties of epilepsy are carefully treated by the physician with strong elimination and alleviation therapies according to the Doshas vitiated.
When the epilepsy caused by the vitiation of Doshas gets associated with extrinsic causative factors then therapies as would bring the Doshas into normalcy and also correct the affectation of extrinsic causative factors- say the wise physicians. [11-14]
The physician, well versed in the specific characteristics of all diseases and the properties of all medicine s cures all diseases and do not get confused. 
Thus the section par excellence on the “Diagnosis of Diseases ‘ are described in its entirety.
Diseases as causative factors
Diseases as causative factors for other diseases:
Diseases act as causative factors for other diseases as well; for example,
Raktapitta (the disease characterized by bleeding from different parts of the body) is produced by the heat of the Jvara (fever);
Jvara is also produced by Raktapitta
Ascitis is caused by the enlargement of spleen;
Shotha (General oedema) due to ascites, painful ascitis and Gulma due to piles:
Kasa (coughing) due to Coryza;
Kshaya (Wasting) of tissue elements due to Kasa and
Sosha (Consumption) due to wasting of tissue elements. [16-19]
Causative factors as diseases in stages:
These conditions in the primary stage manifest themselves as diseases and subsequently they act as causative factors of other diseases. They are found acting both as the disease and causative factor: some of them act in one way also –either as a disease or as a causative factor: 
Nature of disease:
Some disease gets subsided after causing another disease and some others even after causing another disease do not subside.
For example, coryza may continue to exit along with Kasa (coughing) after causing the latter; and at times after causing Kasa, coryza itself may get subsided. In the former case, coryza is considered both as a disease as well as a causative factor, in the latter case it acts only as a causative factor. \
Difficulty in cure:
Such combination of diseases due to the incorrect administration of therapies or production of one disease out of the other, makes the condition difficult of cure. 
Correctness of therapy:
The therapy which while curing one disease provokes another is not the correct one, the correct therapy, is the one which while curing a disease does not provoke the manifestation of other diseases. 
Productivity of Causative factors:
One causative factor may produce many disease, e. g due to dry causative factors many diseases like fever, giddiness and delirium are manifested. One causative factor may produce fever alone. Many causative factors may produce only one disease e.g fever alone may be caused by many causative factors may produce many diseases, e.g many diseases, viz dryness, hot and saline substances. [24-26]
Relation of Symptoms with disease:
One symptom may be common to many diseases; e.g fever may be the common symptom of many diseases having irregularity as their onset. One symptom may be related to only one disease. E.g hyperpyrexia is the symptom of fever alone. Many symptoms may be common to many diseases, e.g many symptoms like irregularity in onset may be common to many diseases, like fever, asthma and hiccup. [27-29]
Effect of therapy on disease:
One single therapy may cause many diseases, e.g diseases having their origin from Amashaya (stomach including small intestine) are cured by fasting. There may be one single therapy only for one disease e.g fasting is a therapy for the cure of fever alone. There may be many therapies for one disease, e.g intake of light diet etc., cures only one disease, viz fever. There may be many therapies for many diseases, e.g intake of light diet etc. may cure many diseases viz, fever, asthma, hiccup etc. [30-32]
Definition of curable, Palliable and incurable diseases:
Easily curable diseases are cured by simple measures in a short time. Disease which are difficult of cure involve much of effort and they take a long time for cure. The palliable variety of incurable diseases can never be eradicated from the root. The irremediable variety of an incurable disease is not amenable to any type of treatment.
The incurable varieties never become curable; the curable variety may on the other hand become incurable. Due to the defects in the four agents of therapeutic or due to misfortune, the easily curable variety may become difficult of cure: diseases which are difficult of cure may become palliable and palliable variety may become irremediable. [33-35]
Observation on the states of disease:
A wise physician should closely observe the subtleties of aggravated, normal and diminished states of diseases, body, and power of digestion, strength and mental faculties. Having close acquaintance with the various states of the disease, an intelligent physician should prescribe for these difficult states such therapies as would help attainment of the four- fold blessings. [36-37]
Principles of treatment
If the aggravated Doshas spread sideward’s then the patient continues to be afflicted with the disease foe a longtime. One acquainted with nature of the body, power of digestion and strength of the individual should not administer strong therapies for the treatment of this condition.
By administering slow acting therapies in small Doshas, such diseases should either be suppressed or brought to the Kostha (alimentary tract) with ease. Having known of their arrival in the Kostha, the wise Physician should eliminate these Doshas from their respective abodes by the administration of appropriate therapies. [38-39]
Symptoms and disease difference
Difference between symptoms and disease:
In this section on the “Diagnosis of Diseases” Jvara (fever) etc., are described to have some symptoms, viz Aruchi (anorexia) etc. these symptoms in themselves also constitute diseases. But here, because of their subordinate nature, they are only symptoms and not diseases. 
Dependence of causes
All manifestations relating to the body and soul can briefly be categorized into two, viz. normal and abnormal, and both of them are dependent upon causative agents- none of these manifestations can continue in the absence of these causative agents. 
To sum up: Causes, premonitory, symptoms, actual symptoms, homologation, pathogenesis, first origin (mythological) and the brief line of treatment of epilepsy are described in this chapter.
Curability or otherwise of the 8 diseases, viz fever etc., description of etiology, symptomatology including premonitory symptoms and treatment including homologation of all diseases in common and individually, symptoms of etiology, disease and symptoms- these are described in brief in this section on the Diagnosis of Diseases. [42-44]
Thus ends the 8th chapter on the “diagnosis of Epilepsy “of the section on “Diagnosis of Diseases” (Nidana sthana) of Agnivesha’ work as redacted by Charaka. Thus ends the “section on Diagnosis of Diseases”.