33° 



HANDBOOK OF PHYSIOLOGY 



NEt'ROPH'YSIOLOCY 



accordiiiE; to the duration of the attack, to the relative 

 importance of motor or mental symptoms and to the 

 characteristics of the EEG discharge. 



GRAND MAL. This is characterized by: a) duration of 

 more than i min.; h") initial total loss of consciousness 

 with postictal coma; c) generalized tonic contraction 

 at first continuous and later interrupted by periods 

 of relaxation which causes the so-called 'clonic' 

 phase; d) a discharge of rhythmical, bilateral, syn- 

 chronous and symmetrical spikes at lo ± 2 cps, the 

 amplitude of which increases while the frecjuency 

 diminishes and in which the terminal elements, sepa- 

 rated by intervals of electrical silence, constitute 

 groups, each corresponding to a jerk in the clonic 

 phase. 



PETIT M.'^L OF '.'^bsencje' VARIETY'. This is characterized 

 by: a) a shorter duration (5 to 20 sec); A) more or 

 less complete loss of consciousness which is ne\cr 

 followed by postictal coma; f) aborti\e muscular 

 contractions, which are hardly discernible and occur 

 three times a second, involving the eyelids and some- 

 times the muscles of the head and upper limbs; and 

 rf) a rhythmical, bilateral, synchronous and symmetri- 

 cal discharge of a complex pattern, comprising a 

 spike followed by a slow waxe and repeated three 

 times a second. 



PETIT MAL OF .MYOCLONIC TYPE. This is characterized 

 by: a) an exceedingly brief duration (a fraction of a 

 second); 6) a single violent jerk which, though gen- 

 eralized, predominantly inxoKes the muscles of the 

 arms or head and sometimes appears on one side 

 only; and f) a short burst of spikes, with or without 

 one or several slow waves, and constituting, as the 

 case may be, multiple spikes, multiple spikes and 

 waves, or even a spike and wave. 



The 'spikes' of grand and petit mal are in reality 

 waves whose form and period differ only slighth from 

 those which characterize the waves of the alpha 

 rhythm and have nothing to do with the spikes, cor- 

 rectly so-termed, of interictal discharges in partial 

 epilepsy. 



Types of Partial Epilepsy 



The.se forms of epilepsy, b\' contrast, constitute an 

 essentially heterogeneous group. 



CLINICAL ASPECTS. From the clinical point of view, the 

 seizures are manifested by mental, .sensory or motor 

 symptoms in\olving the autonomic or cerebrospinal 

 systems, o) The sensory symptoms may be classified 

 as somesthetic, visual, auditory, \ertiginous, olfactory 

 or gustatory. /)) Mental symptoms include all degrees 

 of clouded consciousness and also positi\e phenomena 

 affecting perception, ideation or mood — illusions or 

 hallucinations, 'forced thinking' or conversely a blot- 

 ting out of thought, and feelings of anxiety, fear or 

 anger, c) Visceral symptoms are characterized by 

 abnormal sensations or acti\ities in\oKing the ali- 

 mentary system (abdominal or epigastric sensations, 

 chewing with salivation, borborygmi, defecation, 

 etc.), the cardio\ascular or respiratory systems (pre- 

 cordial pain, tachycardia, vasomotor phenomena, 

 cough, apnea, etc.), and in addition but less fre- 

 cjuently, symptoms in\olving the glands, erectores 

 pilorum, sphincters, pupils, etc. (T) Somatomotor 

 symptoms include abnormal tonic or clonic move- 

 ments, the commonest being desiation and contra- 

 version. Apart from these, there are numerous ab- 

 normal gestures which are responses to hallucinations 

 (gesture of fear during a terrifying vision) or to sensa- 

 tions (for example, the gesture of placing the hand on 

 the abdomen associated with a painful epigastric 

 sensation), or which merely represent the release of 

 automatisms during an ictal or postictal confusional 

 episode. Gibljs et al. (88) proposed the term 'psy- 

 chomotor' for seizures in which there are gestures 

 such as these but especially for attacks with con- 

 fusional automatisms. 



.An enumeration of symptoms cannot ser\'e as the 

 basis for a cla.ssification of the partial epilepsies; it is 

 even less satisfactory relati\e to physiopathological 

 interpretation. It is indeed exceptional for an attack 

 of partial epilepsy to be manifested by a single symp- 

 tom; quite the contrary, most of the seizures simulta- 

 neously involve various sensory, mental and motor 

 phenomena. In addition, it is impossible to locate a 

 precise region of the brain to which the origin of each 

 of the above-mentioned symptoms might be assigned. 

 The conception of "representation' is inisleading (91) 

 when motor and sensory 'representations' are said to be 

 contralateral, homolateral or bilateral, or primary, 

 secondary or supplementary, and to occupy different 

 cortical and subcortical regions. It thus becomes 

 impossible to relate salivation, for example, exclu- 

 sively to the opercular region, or deviation of the 

 head and eyes simply to the 'prcmotor' region. 



