The electroencephalogram in pregnancy

672

.KvlJ+:RICAX

JOURNAL

OP

OBSTEX’RICS

ASD

GYSECOLOW’

T

1-11s study was planned as a preliminary survq of the electJ:WJJcephalogram in pregnancy with the special purpose vf det~erminiw whether the electrical activity of the cortex is modified in normal pregnancy and whether there is a difference between the electrical aut.ivity of the cortex in normal pregnancy and in pregnancy complicatecl b> tosclnia. MBTER,IAL

AND’

METHOD

The electroencephalograms of 2S pregnant women were obtained. Uf these, 20 had normal pregnancies ; 3 had mild pre-eclampsia ; 4 had severe pre-eclampsia; 1 had eclampsia, and in 1 case the pregnancy was interrupted because of heart failure due to severe rheumatic heart tlisease. 1-n 17 cases, an electroencephalogram was obtained after termination of pregnancy. Most of the records were taken in the last two weeks of pregnancy and in the first two weeks post -partnm. The activity of both frontal, parietal, and occipital areas ntart’ recorded on paper with a Grass three-channel elcctroencephalo~ra~~l~. TJnipolar leads were used with the indifferent electrode on the two ear lobes. At the same time, the activity of various cortical areas was rt~~rd~~tl as a shadowgram on film, and analyzed into spectra with the Grass t’t.eqnency analyzer. lIESI’1.‘l’S In all but 3 of the 16 cases where pre- and post-partum rr(tol~~s ~~~t~l~e obtained, cortical activity was slower during than after pregnanc.Lv (Fig. 1). In 2 cases, it. ,was unchanged , and in 011c’,it \\~a8 faster durand

*This the

study was Rockefeller

aided by grants Foundation.

from

the

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?sI;~ty

13. ~apklc

F<,un,latic,n

GIBBS

AND

REID:

ELECTROENCEPHALOGRAM

IN

PREGNANCY

673

ing pregnancy. In 4 cases, a second post-partum record was obtained, two or more months after delivery; in all 4 cases, this record also was faster than the prepartum record. This suggests that the change occurring with pregnancy can be properly regarded as a slowing of cortical activity during and as a return to the pabient’s usual cortical frequency after delivery. Table II contains further evidence that the deviation is in the direction of slowing during pregnancy. From this table it may be seen that 40 per cent of the patients with normal pregnancy had eIectroencephalograms which were classified as slow, a much higher incidence of slow records than has been observed in any normal control series. The comp1et.e absence of high-voltage fast records in this group is also noteworthy. 0

2

4

6

8

10

12

14

16

16 20

22

24

26

28

30 32 34

36 36 40 llIlllll( 44

26 25 20 1: 1I

13

FREQUENCY

Fig. L-Typical shift in the cortical frequency spectrum to the slow side during pregnancy. Elack czwt~, twelve days hefore term; red cwve, one day post partum. and energy in arbitrary units that are Frequency is shown in cycles per second, The spectra were made with a convertible to millivolts. This is Case 4 in Table I. Grass analyzer from records of the electrical activity of the right occipital area.

Slow records occurred as commonly among patients with toxemias as among patients with a normal pregnancy (Table II). The difference between the two groups appears to lie in a greater incidence of highvoltage fast records among p atients with toxemia and in a smaller incidence, of perfectly normal records. In the one case of eclampsia that was studied, the record was obtained during stupor ; the cortical activity at that time was extremely slow. In one case studied just before pregnancy was interrupted because of severe cardiac decompensation, the electroencephalogram was also slow.

674

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,JOUl%NAL

OF

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-4ND

(;PNECOLOC;Y

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1 1 %/set.

Slow

9

/sec. Slow

(100 nonpregnant pregnancy (20 with toxemia

pregnancy

Normal Smndl Sormal

pregnancy pregnancy

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CIJNICAT, DIAGSoSlS

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74

Pre-eclnmpsia Pre-eclampsia Rheumatic

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___---__.DISCUSSION

Slow cortical activity and high-voltage fast activity are common in a variety of conditions associated with evidence of cerebral dysfunction.’ All conditions in which the incidence of convulsions is higher than in the general population are associated with a high incidence of electroencephalograms that are classified as slow or high-voltage fast. !I’onicclonic convulsions are usually accompanied by an abnormal acceleration of cortical activity,2 and grand ma1 seizures can be predicted in epilpptics by an increase in the amount of fast activity.“, 4 The occurrence of abnormally fast activit,y in half of the patients with pre-eclampsia suggests that in pre-eclampsia cortical activity is commonly in a snbconvulsive state. Endocrine and met,abolic factors are known t,o alter the electrical activity of the cortex,z-l” but aI1 increase in cortical frequency, such as occurs with an in.crease in nletabolic rate. coul~~ not explain the present findings, nor would any known change in sugar metabo&m. Detailed consideration of the factors that may be responsible for the

SULLIVAN

AND HEFFERNBN :

CONVULSIONS AFTER PITUITBRY

modification of cortical frequency more data are available. SUMMARY

in pregnancy

AND

EXTRACT

will be deferred

675 until

CONCL.USIONS

An electroencephalographic study of 28 pregnant women, 8 of whom had pregnancy toxemias, indicates t.hat t,he electrical activity of the cortex is slowed in pregnancy and that, as a group, patients with pregnancy tosemias show more high-voltage fast activity and less normal activit.y than patients without toxemia. REFERENCES 1. Gibbs, F. A., and Gibbs, E. L.: Atlas of Electroeneephalography, Cambridge, Mass., 1941, Lew A. Cummings Co. 2. Gibbs, F. A., Gibbs, E. L., and Lennox, W. G.: Arch. Neural. & Psychiat. 39: 298, 1938. 3. Gibbs, F. A., Gibbs, E. L., and Lennox, MT. G.: Brain 60: 377, 1935. 4. Gibbs, F. A.: J. Pediat. 15: 749, 1939. 5. Hoagland, H., Rubin, M. A., and Cameron, D. E.: J. Psychol. 3: 513, 1936. Ii. Lennox, W. G., Gibbs, F. A., and Gibbs, E. L.: Proc. A. Research New. & Mcnt. Dis. 18: 277, 1938; also J. Neural. & Pnyehiat. 1: 211, 1938. 7. Lindsley, D. B., and Rubinskin, B. B.: Proc. Sot. Esper. Biol. & Med. 35: 555, 1937. S. Hoagland, H.: Am. J. Physiol. 123: 102, 1938. 9. Bertrand, I., Delay, J., and Guillain, J.: Compt. rend. Sot. de biol. 129: 395, 1935. 10. Ross, D. A., and Schwab, R. 8.: Endocrinology 25: 75, 1939.

CONVULSIOXS

FOLLOWING

ADMINISTRATION CHARLE’S L. SULLIVAN,

M.D.,

THE

INTRAVENOUS

OF PITUITARY AND ROY J. IIEFF!GRN$N, BOSTON, MASS.

EXTRACT lf.D.,

F.A.C.S.,

A

THOROUGII survey of the literature concerning the use and abuse of posterior pituitary extract in obstetrics reveals that the vast majority of clinical and laboratory investigators condemn its indiscriminate use in the first stage of labor; sanction a judicious use in the second stage and generally laud its beneficent properties in the third stage. It is probably fair to assume that many obstetricians use pituitary extract without much consideration of the possible toxicolo,gy involved. In 1933 the senior author1 reported the intravenous use of the extract in 100 cases of cesarean section with uniformly good results and no toxic effects. In 1936 Pastore’ reported on the use of the drug in the third stage of labor and in the control of post-partum hemorrhage, used intravenously, with one death due to shock. White,3 in 1938, reported the intravenous use in 630 cases with no bad results. In 1940 Gardiner, Sprague, and Bradbury* found that the intravenous use of the drug was