Convulsions.
A convulsion is a temporary overflow of motor impulses producing purpose less muscular contractions, alternating with relaxations for shorter or longer periods, attended by more or less loss of consciousness. If the alternations are rapid, the form is called clonic; if slow, the contractions being maintained for a variable time, it is called tonic. A spasm is a more or less rapidly alter nating contraction and relaxation of certain muscles or groups of muscles affecting a limited portion of the body; it is essentially local, and, as a rule, does not involve the centres nor dis turb consciousness. A tremor is a rapid rhythmical vibration in the muscles. Convulsions may be epileptiform, hys teroidal, or tetanic. In epileptic and hysteroidal convulsions consciousness is disturbed because these emanate from the brain-centres. In the tetanic form this is peripheral, and not central. In epileptic convulsions consciousness is lost or severely impaired, as a rule. In hys teria this is also true at times, wholly or in part, but is not to be expected. Local spasms may occur as disturbances of tion in the muscles of the vital organs, such as oesophageal, rectal, urethral, and the like. Vomiting is a local spasm; so are certain forms of nervous croup. Spasms of voluntary muscles in young children produce such alarming effects as laryngeal spasm, or laryngismus strid ulus, child-crowing, and the like.
Automatic movements are irregular, involuntary muscular acts, more or less co-ordinated, and simulating voluntary acts.
Infantile Convulsions. — Convulsions occurring in young children constitute a symptom, not a disease. They vary widely in severity, beginning locally and becoming general, or they may prove to be overwhelming motor discharges so in tense as to cause serious disablement or possible death. Modern writers deny the gravity of infantile convulsions, so far as immediate results are concerned, but readily admit that very grave subsequent effects often follow.
After-history personally studied in 85 cases of infantile convulsions, 40 of whom suffered from pronounced neuroses in later life. Of these 11 had epilepsy of a severe form, 14 had petit mal3 5 suffered from somnambulism, 4 from melancholia, 7 from chorea, and 9 from migraine. Of the 45 who were free from definite neuroses, 8 were pronouncedly eccentric, and nearly all the rest were below the average intelligence of their brothers and sisters. Coutts (Brit. Med. Jour., Apr. 19, '99).
Symptoms. — Almost anyone of mod erate intelligence will readily recognize a well-marked convulsion or even a con vulsive tendency; but it is of the utmost importance that the first observer shall carefully note and be able to relate ac curately the starting-point and phenom ena of progress, the degree of severity, and the length of time it has persisted. On these facts will depend a proper diag nosis of the character and seat of the irri tation. The slightest twitching of the thumb may indicate irritation or disease near the thumb-centre. So twitchings of the eyelid or movements in and around the corners of the mouth point to cen tral disease. Unilateral convulsions do not necessarily indicate a local lesion, although they form a fair ground for suspicion of focal disease. There is usually some prodromal symptom more or less brief, such as slight twitchings alluded to in the muscles of the ex tremities or face, a general restless ness, and startings upon slight irrita tion from touch or noises. Immediately before the convulsion there is often pallor, a fixity of the eyes, or they may be rolled up into their orbits; these slight, isolated movements may pass into convulsive twitchings, extending rapidly over the entire body, or shifting from one side to another, or from one limb to the opposite one along with, or alternating with, movements in the face or head, re traction of the head, or rolling of the body over to one side or the other.