Brain Damage and
Memory Loss from ECT
Testimony Prepared for the Standing Committee on Mental Health of
the Assembly of the State of New York.
October 5, 1978.
by Dr. Peter Sterling, Ph.D.
Associate Professor of Neurobiology
Department of Anatomy
School of Medicine
University of Pennsylvania
Scope and Complexity of the Brain
The brain is the controlling organ of the body. It receives
information from the outside world through the 5 senses. It also
receives information from the inside of the body regarding all the
body's internal functions: heart rate, blood pressure, amount of
glucose (sugar), oxygen, carbon dioxide, hormones, etc., in the
blood. It also contains information, coded originally in the genes,
regarding the needs that all humans share: the drives for hunger,
thirst, sex, and so on. As particular kinds of information is taken
into the brain by the various sensors, it is stored. Old
information, when needed, is retrieved for comparison with new
information so that decisions can be made.
These decisions include the obvious, conscious ones, such as
whether we shall get out of bed in the morning, or what clothes we
shall wear. They also include decisions of which we are not
conscious that have consequences for every cell in the body, such as
how high the blood pressure should be, how much of a particular
hormone should be secreted, how much blood should be distributed to
one organ or another.
The Demands of Complexity
It is a general rule that the more complex a structure is, the
more closely regulated its operation must be. In a complex
structure, foundations must be firmer and the tolerances closer. The
safeguards against disruption must be numerous and of a
"fail-safe" variety. A simple hut needs no foundation but
there can be no mistakes in the planning or construction of a
skyscraper. The simpler the structure, furthermore, the less
vulnerable it is to disruption. A hut will most likely survive an
earthquake and in any case can be repaired, but a skyscraper, even
with all its safeguards, is subject to irreparable collapse. This
rule applies to the body as well. Let us compare a relatively simple
tissue, the skin, to the most complex organ, the brain.
The skin is exposed directly to the environment and is frequently
damaged by mechanical trauma. Its cells have the capacity to divide;
new cells easily replace worn or damaged ones. Skin cells must be
supplied with nutrients and oxygen from the blood, but their
requirements are quite flexible. They can metabolize a variety of
substances: fatty acids, glucose, amino acids; they can operate for
a while without oxygen and can tolerate wide variations in blood
supply. The skin cells are not very sensitive to temperature -- that
is why we can sit in the sun or plunge into ice water without
damage.
The brain is entirely different. Its 10-100 billion neurons are
all present at birth. Nerve cells do not divide to replace their
losses. Therefore, any loss of cells is permanent. The death of a
single neuron represents a loss of up to 100,000 inputs and 100,000
outputs for a total loss of 10 billion connections. Obviously, the
brain must be protected from mechanical trauma.
The brain, unlike the skin, has virtually no metabolic
flexibility. It can metabolize only glucose and not fatty acids or
amino acids. This is one reason why the glucose levels in the blood
must be maintained at all times. A sharp fall in blood glucose leads
rapidly to failure of brain function and coma. Oxygen supply to the
brain must also be maintained for there is hardly any reserve
supply. If a pressure cuff is placed around the neck and inflated, a
human subject goes blind and loses consciousness in 6 seconds. If he
breathes pure nitrogen, consciousness is lost in 17-20 seconds.
After 3-4 minutes without oxygen at normal body temperature, there
is generalized brain damage; after 4-5 minutes, the damage is
irreversible.
Brain temperature must also be closely regulated. Everyone is
familiar with their own experience with the deterioration of brain
function that occurs in fever where temperature rises only a degree
or so above normal. Aspirin, by restoring normal temperature, brings
relief. Temperature rises that are only slightly greater than a
common fever may cause convulsions and can do permanent damage.
Clearly, brain function cannot withstand the extreme changes in
blood glucose, oxygen supply, or temperature that bother the skin
not at all.
Protective Mechanisms of the Brain
Mechanical protection. The first level of mechanical protection
for the brain is the thick bone of the skull. There is an active
protection too: because the skull has sensitive nerve endings on the
outside, we learn early not to bang it into hard objects. Inside the
skull, the brain is protected by 3 separate layers of casings. There
is a tough, fibrous outer casing called the "dura"
("hard"). Beneath the dura there is a second, more
delicate membrane called the "arachnoid". This encases the
brain in a special fluid called "cerebrospinal fluid"
("cSF"). Thus, the brain is suspended in fluid in the same
way the delicate embryo is suspended within the womb. Within limits,
mechanical shocks to the head are absorbed by this fluid and are not
transmitted to the brain. The third membrane layer is called the
"pia". It is applied directly to the brain's surface,
forming the last major protective barrier. Blood vessels must
penetrate the pia to reach neural tissue itself.
Protection of blood supply. Even though the brain is only about
2% of the body's weight, it uses 20% of the body's oxygen supply
because of its high rate of metabolism. The brain controls its own
blood flow and gives itself highest priority along with the heart.
If there is not enough blood to go around, the blood supply is shut
down to the gut, kidney, skin and muscle -- always to preserve flow
to brain and heart. If blood pressure falls so low that the heart
has difficulty pumping blood to the head, the brain shuts off
messages to muscle, causing collapse (fainting). With the head at
the same level as the heart as a result of fainting, the crucial
blood supply can more easily be maintained. Thus, fainting is an
important protective mechanism for the brain.
Blood flow through the brain itself is automatically regulated so
that it doesn't depend on changes in blood pressure for the body as
a whole. If the systemic pressure falls, valves in the brain's
vessels open up a bit to maintain flow. Another role for these
valves is to protect the delicate brain capillaries from excessively
high pressures. This control of blood flow and pressure breaks down
during convulsions, a point to which we shall return.
Protecting the brain's chemical composition: the blood-brain
barrier.
In most tissues the blood vessels are somewhat "leaky".
Although red blood cells do not normally escape, some large
molecules, such as proteins, and many smaller molecules do escape
from vessels into the surrounding tissues. Were this to occur in the
brain, it could be disastrous. First, the tiny channels between
nerve cells could be plugged by larger molecules and barriers would
be established to the normal flow of ions and nutrients. Second, if
large molecules leaked from vessels into the brain, water would
follow them (to maintain osmotic neutrality). The tissue would then
swell. Although most tissues can swell and shrink without causing
any difficulty, swelling is a serious matter for the brain because
it is encased in bone. If it were to swell, pressure inside the
skull would build up. Delicate structures would be squashed against
bone, and the blood supply would be cut off by the rise in
intracranial pressure. Third, the composition of the blood varies
somewhat, even though it is regulated by kidney, liver and other
organs. The blood sometimes contains toxic substances that some
tissues, such as liver, can handle, but which may damage the brain.
In general, the brain's chemical composition must be regulated far
more perfectly than that of any other organ.
Accordingly, there are several lines of defense against changes
in the brain's chemical composition that would result from leaky
blood vessels. These defenses are referred to collectively as the
"blood-brain barrier First, the vessels are sealed off from the
brain by mechanical adhesions between the cells called "tight
junctions". Second, a set of select substances that the brain
needs are actively pumped into the brain from the blood. Third,
undesirable substances, or those whose concentration must be
actively controlled in the brain, are actively pumped out of the
brain. You can get some feeling for these processes in slide 1. The
brain on the left is from a cat with an intact blood-brain barrier.
Blue dye which was injected into the blood was prevented from
entering the brain by the blood-brain barrier. All the other
tissues, however, are blue. On the right, the blood-brain barrier
has been destroyed by irradiation (Klatzo and Seitleberger, 1967).
Here, the vessels have become leaky and dye has penetrated the
brain. This slide, therefore, has two purposes: to illustrate the
existence of the blood-brain barrier and to indicate that it can
break down under certain insults. This will be highly relevant when
we consider the effects of electrical shock.
Protection of neural stability by inhibition.
One additional protective mechanism must be described before the
effects of electrical shocks can be assessed. Nerve cells can either
"excite" (turn on) or "inhibit" (turn off) each
other. The inhibitory mechanisms are important here for one
particular reason, inhibition serves to dampen the excitation, and
without it the excitatory tendencies of nerve cells go out of
control. All cells tend to be excited simultaneously and tend to re
excite each other until massive neural activity swamps out any
sensible, coordinated pattern. Such generalized excitation leads to
massive, sustained contraction of the musculature, called a
"fit", a convulsion, or a "seizure". Thus, a fit
or seizure is a state in which, for one reason or another, the
excitatory processes in the brain temporarily overwhelm the damping,
inhibitory processes. A seizure, therefore, is evidence that one of
the brain's protective mechanisms has temporarily been overwhelmed.
To summarize:
1. The brain is an organ of extraordinary complexity and is more
complex in man than in lower animals.
2. Its complexity makes it extremely vulnerable to the slightest
environmental insults which other tissues of the body could
withstand. Neurons once lost as the result of insult are not
replaced.
3. To prevent insult, many protective mechanisms, including
mechanical, physiological, and behavioral mechanisms have evolved.
Relation Between Observations on Humans and Non-Human Mammals
I have showed a slide from the brain of a cat and will continue to
refer to studies on other mammals. It is appropriate to ask,
therefore, whether these studies are pertinent to the human brain
since there are many differences between human and animal brains.
The major difference between humans and animals that is relevant in
the present context is that the human brain is a greater and more
complex edifice. To return to the earlier analogy, it is more like a
skyscraper than a hut. It needs even more protection, not less. All
the protections I have discussed so far exist in humans and are, if
anything, exaggerated in humans. In the remainder of my testimony, 1
shall refer to animal studies only where we can be reasonably sure
that the human tissue would react in the same general way.
Effects of ECT on the Brain
We are now in a position to appreciate some of the effects of
electrical shocks to the brain. Let us begin by describing the
nature of the shock itself (reviewed by Grahn, et al., 1977).
Typically, the electrodes of the ECT instrument are placed on the
temples. Such ECT instruments usually contain nothing but a simple
transformer that steps up the voltage from the wall outlet from 110V
to about 150V. The machine may or may not have an automatic timing
device to limit the duration of the shock. The current that passes
through the head (between the electrodes) is limited mainly by the
electrical resistance of the head. The total power drawn is about 60
watts -- enough to light a conventional light bulb. The result is
not very different from what would be accomplished by plugging 2
pieces of metal into a wall outlet and placing their other ends on
the temples -- except that the voltage from the wall outlet is a
little lower. The duration of a typical ECT shock is 1/10-3/4 of a
second.
Events triggered by electrical shock.
The electricity passing through the brain causes massive,
simultaneous excitation of vast numbers of neurons. The inhibitory
mechanisms that normally hold neurons in check and shape the normal
EEG rhythms are overwhelmed by the excitation. As the excitation
builds and swamps the inhibitory mechanisms, it spreads throughout
the brain. When the excitation reaches the motoneurons of all the
body's muscles, there is massive, convulsive muscular contraction.
The muscles contract so powerfully that tendons may be torn from the
bones, the bones themselves may be broken, teeth chipped and broken,
and so on. The massive requirements for oxygen and the interruption
of breathing caused by the convulsion often causes anoxia.
Accompanying the convulsion, there is a tremendous rise in blood
pressure: changes in arterial pressure from 80mm Hg to 220mm Hg, or
almost 200%, have been recorded (Plum, et al, 1968). This overall
response resembles the "grand mal" seizure that occurs in
epilepsy.
In recent years some of these consequences of the electrical
shock have been ameliorated. The muscle contractions can be
prevented by administration of a drug that blocks transmission of
impulses from nerve to muscle. The ensuing paralysis protects bone
and muscle, and also permits oxygen to be administered by artificial
respiration. Under these conditions, the brain is well protected
from anoxia. On the other hand, this procedure (paralysis) is
frightening. Patients are therefore usually pretreated with
barbiturate anesthetics so that their consciousness of their
treatment is dulled or lost entirely. The effect of barbiturate
anesthetic is to decrease the excitability of neurons in the brain.
Larger shocks must, therefore, be employed to evoke a grand mal
would be needed without the drugs. Thus, although the patient may
gain from the paralysis and the administration of oxygen, he
probably also loses by the higher voltage requirement. There is no
evidence that these drug treatments substantially alter the
electrical and chemical phenomena within the brain that I shall now
describe.
Brain changes during ECT.
The massive neural activity evoked by the electrical shock causes
and requires major changes in the metabolism and blood supply of the
brain.
1. The neurons, because they are so active, require much more
oxygen and nutrients. Therefore, with the onset of the seizure,
cerebral blood flow rises dramatically -- as much as 400%. Cerebral
oxygen consumption also rises as much as 400%. In accomplishing such
massive increases in blood flow, the automatic mechanisms that
normally regulate cerebral blood flow are overwhelmed. For the
duration of the seizure and for sometime following it, blood flow to
the brain becomes like that of must other tissues in the body --
proportional to the arterial pressure forcing the blood through the
vessels. These changes accompanying ECT are not modified by the
administration of anesthetic, paralytic drugs or oxygen (Plum, et
al., 1968; Posner, et al., 1969).
2 The extremely high cerebral blood pressure and the breakdown in
auto regulation of cerebral blood flow during the seizure frequently
ruptures small, and occasionally large, vessels in the brain. Madow
(1956) reviewed 42 cases of autopsy assembled from 26 published
reports on patients who had recently received ECT. Twenty-five (60%)
had either petechial hemorrhages or large infarcts. About
three-quarter of these patients were over forty, but the frequency
of hemorrhage in the group under forty was the same as for the older
group. There seems every reason to suspect, therefore, that
subarachnoid or intracerebral bleeding accompanies ECT about half
the time. This is supported by numerous studies in animals autopsied
after being subjected to ECT. For example, Alpers and Hughes (1942)
found bleeding in 23/30 cats (77%); Heilbrunn(1943) found petechial
or larger hemorrhages in all of the rats that convulsed in his
experiments to ECT; Heilbrunn and Weil (1942) made similar findings
in 17/21 (81%) rabbits. Wherever bleeding occurs in the brain,
neurons lose their supply of oxygen and nutrients -- and die.
Some studies failed to hemorrhages in animals following ECT, but
most of these seem not comparable to the human cases. in two, the
voltage applied was far below what is employed on humans (Masserman
and Jacques, 1947; Winkleman and Moore, 1944). Others used only a
single shock rather than, as is common for humans, a series of
treatments (Windle, l948, Alexander and Lowenbach, 1944). Another
study with negative findings.(Siekert, et al, 1950) used a small
sample (5) of young monkeys (5-7 lbs., corresponding to an age of
about one and a half years). Since damage is greater in older
animals with less flexible vascular systems (Hartelius, 1952), this
negative result on a small sample is not astonishing, nor does it
contradict the many positive findings of damage. The positive
findings cannot be attributed to poor preservation of the brains
after death. While poor preservation makes difficult judging the
condition of neurons or glia, it cannot cause bleeding within the
brain. Nor can the bleeding be attributed to "old" methods
of ECT (no paralysis or oxygen). One would expect under the old
conditions the brain to be anoxic, with arrested circulation. This
would lead to a lack of blood in the brain, the opposite of what is
reported. Thus, the later modifications of ECT can relieve the
threat of cerebral anoxia, but not the threat of high pressure,
bleeding, loss of blood-brain barrier, or edema
3.The electrical shock causes damage to the blood-brain barrier.
Aird, et al., 1956; Angel, et al., 1965; Lee and Olszewski, 1961).
This has been shown experimentally in animals, and there is every
reason to believe that it happens in humans as well. Whether this is
caused by the huge rises cerebral blood pressure is unknown.
Whatever the cause, the loss of this protective barrier exposes the
brain tissue to components of the blood from. it is normally
protected. For example, if a patient has been taking drugs of any
kind, the brain may be exposed to much higher levels of the drugs
than normally cross the blood-brain barrier.')
4. The combination of raised cerebral blood pressure and ruptured
blood-brain barrier often causes another problem, cerebral edema.
The high pressure forces proteins and other substances out of the
now "leaky" vessels into the brain tissue. As noted
earlier, fluid tends to follow these substances and the tissue
begins to swell. This process once started can become disastrous
because a "vicious circle" is started. As the pressure
inside the skull rises from the swelling, capillaries are closed.
Their linings are damaged by anoxia making them even more leaky.
This leads to more edema and damage (Fishman, 1975; Klatzo and
Seitleberger, 1967). Edema has been noted in the human retina, an
easily visible part of the brain, as a consequence of shock (Winnik,
et al., 1966). Patients cannot be protected from this process by
drugs that lower blood pressure, because the extra pressure is
needed to supply the brain's huge metabolic needs during the
seizure. It has been noted in experimental animals and man that
rises in blood pressure accelerate the spread of edema (Fishman,
1975; Shutta, et al., 1968; Klatzo and Seitleberger, 1967) and the
leakage of trace materials from the blood-brain barrier (Lee and
Olszewski, 1961; Klatzo and Seitleberger, 1967). It has also been
noted that individuals with high blood pressure "have a
significant predisposition to cerebral edema" (Klatzo and
Seitleberger, 1967, P.148). Where the swelling is great enough to
block the blood supply to neurons .-- or even to slow it below the
extreme needs of the active tissue -- nerve cells will become anoxic
and die.
5. Even where there is adequate oxygen, neurons may die because
they use up the metabolites that they need to function, It has been
demonstrated that during a seizure, the "respiratory
quotient" of the brain shifts markedly. This shift indicates a
change in cerebral metabolism away from the use of glucose as fuel.
Here is what a prominent neurology group had to say about the
changes in cerebral metabolism that they measured during ECT-induced
seizures in man:
If endogenous substances essential to normal cerebral metabolism
are depleted during seizures, one might expect post-ictal brain
dysfunction until repletion even without hypoxia. At some point
during repeated seizures, depletion of cerebral substances might
become irreversible and permanent brain damage ensue. Thus, post
ictal EEG flattening and coma need not imply cerebral hypoxia
(Posner, et al., 1969, P.394).
Translated into English, this means that even if the brain
receives enough oxygen during a seizure. the brain may exhaust its
sources of nutrients and be irreversibly damaged. It means that the
abolition of electrical activity and the coma that sometimes follows
a seizure can occur even though adequate oxygen is supplied.
6. There are changes in a host of brain chemicals as the result
of ECT (reviewed by Essman, 1973). Synthesis of protein and RNA are
inhibited within five minutes of ECS, with the decrease persisting
for a number of hours. The levels of neural transmitters (acetylcholine,
norepinephrine, serotonin) and their related enzymes also change.
For example, acetylcholine and the enzyme that destroys it,
acetyicholinesterase, fall after ECT but rise above normal levels
within 2 hours. These changes are reflected in the choline levels in
the cerebrospinal fluid, which in man and monkey are increased 24
hours following a single ECT and remain elevated for at least a week
after multiple ECT. Changes in serotonin, an important neural
transmitter, last up to 5 months. The time courses of these changes
are very complex, and their meaning is not yet understood.
Nevertheless, each of the chemicals listed has been shown to play
some role in memory, and I would anticipate that significant changes
in any one of them might contribute to the changes in memory that
have been demonstrated to follow ECT.
7. Following ECT, there is a marked rise-in cerebral levels of
arachidonic acid (Essman, 1973; Bazan, N.G., 1970, 1971). This
compound has been shown to cause aggregation of blood platelets when
injected d into the cerebral blood supply, resulting in small
"strokes" throughout the brain (Furlow, T.W., Jr. and
Bass, N.H., 1975). Conceivably the rise. in arachidonic acid
associated with ECT could be a source of the brain damage to be
described later.
Changes in the Electroencephalogram (E.E.G.)
The EEG changes markedly during and following ECT. Before describing
these changes, it is necessary to explain what the EEG represents.
The electrical activity of neurons can be studied in two ways --
either by recording the electrical activity of one neuron at a time
to see how it responds to particular environmental events -- or by
recording outside the skull from a large population of neurons and
their supporting "glial" cells. It is something like
pushing a microphone close to one member of an orchestra (single
neuron) and listening to his theme or withdrawing the microphone in
order to listen to the whole (EEG). In the first case, one can make
out the individual notes; in the second, one hears the overall
rhythm, pitch, and loudness, but blended in such a way that the
detailed contributions cannot be discerned.. When the rhythms of
millions of individual nerve cells are merged in the EEG, the
resulting broader rhythms have fairly characteristic features in
normal and pathological states. When something is wrong, one cannot
identify precisely what it is -- especially since glial cells as
well as nerve cells contribute to the EEG rhythm -- but one can be
sure that something is wrong. In awake adults, a beta-rhythm is
normally seen with a frequency of about 15-60/ sec. and an amplitude
of 5-10uV (low voltage-fast activity). If the person closes his
eyes, the rhythms, particularly over the visual area, may slow a
little and increase in amplitude, changing to an alpha-rhythm of
8-10 sec., 5OuV. In sleep the rhythm slows to a delta-rhythm, still
slower (1-5/sec.) and higher in amplitude (20-200uV).
These slow delta rhythms are rarely recorded in normal, awake
adults. They do appear, however, in various pathological states and
are interpreted as evidence of pathology such as tumor, epilepsy,
raised intracranial pressure, mental deficiency, depression of
consciousness by toxic or other factors. For example, lack of oxygen
and lack of glucose in the brain both cause the appearance of these
large, slow delta waves. Again, we cannot say precisely what these
rhythms mean or how they arise from the individual elements, but
they do seem to convey the overall "mood" of the brain.
It is not at all surprising that the EEG is altered during the
ECT seizures because the seizure itself is an interruption of the
normal electrical rhythms. Furthermore, it is to be expected that
the EEG would be abnormal for some time after a seizure because of
the outpouring of potassium ions from neurons. It is significant,
however, that in many patients the EEG remains abnormal for many
months. Here, I should like to cite several studies in some detail.
In 1944 Mosovich and Katzenelbogen studied the EEGs of 82
patients before and after ECT. Although the study is old, it is a
model of good scientific work, particularly in that it studied
patients before treatment and followed them for 10 months
afterwards. The currents used were 300-600MA, within the range used
today. The study showed that of 42 patients with normal EEGs before
ECT, half (21) had abnormal EEGs following treatment. One-third of
these abnormalities were severe "cerebral dysrhythmias".
The EEG patterns resembled those commonly seen in epileptic patients
in the periods between epileptic seizures. Of 40 patients with
moderate EEG abnormalities before ECT, 13 showed cerebral
dysrhythmia afterwards. To produce these changes a relatively few
sessions sufficed, for they were found in 9/60 patients who had only
3-15 ECT. The frequency of damage increased with increasing number
of shocks:. after 16-42 shocks, half the patients (11/22) showed
cerebral dysrhythmia... These changes were often extremely long
lasting. Thus, 68/82 patients showed the dysrhythmia the day
following ECS, and 20 patients still had the pattern 10 months
later. For all anyone knows, the changes were permanent (Mosovich
and Katzenelbogen, 1944).
These findings have been confirmed in modern studies using
anesthesia, oxygen, and muscle paralysis. For example, Abrams, et
al. (1972) found significant slow delta waves when either bilateral
or unilateral ECS was administered. When the shock was restricted to
one side, the EEG changes were found on that side. Volavka, et al.,
(1972) showed that the amount of delta activity in the EEG was
related to the number of shocks administered. These studies had the
additional advantage that the EEG expert who read the records did
not know how the patients had been treated, i.e., the readings were
done "blind". (Abrams, et al 1., 1972) cite four
additional studies done between 1965-1970 with similar EEG findings.
Summary and Conclusions Regarding the Effects of ECT on the Brain
1. During a seizure induced by ECT, there is a tremendous rise in
blood pressure and a breakdown of the blood-brain barrier. These two
events separately or in combination often cause hemorrhage, edema,
and possibly toxic effects because the brain is exposed to chemicals
in the blood from which it is normally protected. All of these
phenomena cause the irreversible death of neurons in the brain
(reviewed by Blackwood and Corsellis, 1976).
2. ECT alters the metabolism of brain proteins, RNA, and neural
transmitters whose production is normally regulated carefully.
Although the gross metabolism of these substances may later return
to normal, their temporary alteration may have permanent effects in
the brain. In fact, the very reason that hundreds of scientists
around the world are studying the relation between these substances
and memory is because small changes in their production might be the
way that memories are stored.
3. EEG studies spanning a 28 year period show that ECT alters
brain physiology from normal to abnormal. These changes, principally
a slowing of the EEG waves, are similar to those found in epilepsy,
mental deficiency, and other neuropathologies. The EEG changes
associated with ECT appear to be extremely long-lasting very
possibly they are permanent. They do not tell us whether a patient
has lost his memory -- for that you have to ask the patient. They do
tell us that ECT can cause profound alterations in brain function.
4. All of the changes that follow ECT vary from animal-to-animal
and from person-to-person. Thus, blood pressure rises in one study
were small in one case, only 23%, but large in others (up to 400%).
Cerebrovascular hemorrhages are found commonly, but not invariably
(about 60% of the time); similarly, about half the patients show EEG
abnormalities.
Loss of Memory for Past Events Following ECT Losses of memory for
past events commonly occur following insult to the brain, for
example, following mechanical injury or from chronic toxic states
such as alcoholism (Russell, 1971; Whitty and Zangwill, 1966). It
should not be surprising that memory loss also accompanies the
damage done to the brain by ECT. Such losses have been documented in
numerous case reports dating back to the 1940s (Levy, et al., 1942).
In some cases the loss is catastrophically complete: memory is
erased for professional skills as well as orientation to places and
friends (e.g., Roueche, 1974). More commonly, the loss is
"patchy": some events are lost while others are
remembered; recent events are more likely to be lost than those in
the distant past, but amnesia can extend backward for several years
and can include events of early childhood that date back 20 to 40
years; some memories return while others do not (Janis, l948; A
Practicing Psychiatrist, 1965; Brody, 1944; Valentine, et al, 1968;
Medlicott, R.W., 1948; Squire, et al, 1975).
One's confidence that there must be substance to these case
reports is strengthened by the hesitations of some physicians
experienced in the use of ECT to employ it on patients engaged in
intellectual work (e.g., Stromgren, 1973) and in the widespread
adoption, especially in Europe, of unilateral ECT. In this method
the electrodes are not placed on both temples, but on one side of
the head only, in the frontal and parietal regions. The passage of
current is therefore largely restricted to one side of the brain.
The electrodes are usually placed on the so-called
"non-dominant" side, the side concerned with spatial,
rather than verbal tasks. With this treatment the EEC changes are
limited to the non-dominant hemisphere, and patients, report fewer
and less severe losses of memory for past events. Clearly, in order
for there to be less memory and loss and less brain damage (EEC
changes) with unilateral ECT, there must be substantial amounts of
it with bilateral ECT (Abrams, et al., 1972; Stromgren, 1973;
Valentine, 1968; Zinkin and Birtchnell, 1968; D'Elia, 1970; Heshe
and Roeder, 1976; Lancaster, et al., 1958). Lest it be prematurely
concluded that no damage is done by unilateral ECT to the
"non-dominant" hemisphere, it is well to realize that the
functions of this hemisphere are just beginning to be appreciated
and that methods for assessing its function remain primitive (e.g.,
Ornstein, 1973).
Various objective tests have been used to determine whether
memory loss occurs following ECT, including standard IQ. tests, the
Benton test, the. Paired Associates test, and tests devised
specifically for assessing memory following ECT (e.g., Bender, 1947;
Brunschweig, et al., 1971; Dornbush, et al, 1971; Squire and Chace,
1975). Most of the tests require the patient to learn and remember
new material of very simple kinds. For example, can a patient
memorize a list of words, numbers or faces and recall them after an
hour, a day or a few weeks? Others test recognition of remote events
that are not intimately connected with the patients' lives, for
example, recognition of the names of old television programs (Squire
and Chace, 1975). One of these reports shows that patients have more
difficulty recalling their own past than in learning new material
and that amnesias recover more slowly than do the processes required
for new learning (Brunschweig, et al., 1971). Until recently, such
tests revealed very little impairment, and it was common to conclude
that patient reports of memory loss are nothing more than complaints
associated with their illness or merely an underestimation of their
true memory abilities (Squire and Chace, 1975). No study, however,
has tried to document this hypothesis, and several solid studies
reporting substantial memory losses find no association between the
degree of memory loss and the patient's emotional health. Teuber, et
al., (1976) studied 34 patients who had been subjected to
cingulotomy (brain surgery) for relief of their mental illness. Many
of these patients had been subjected to ECT prior to their surgery.
On a battery of nine standardized psychological tests, significant
deficits were found correlated not with the surgery but rather with
the patients' history of ECT.
"We found that individuals whose prior treatments had
included ECT were inferior to normal control subjects and to
patients who had been spared ECT, and this inferiority was apparent
on the following measures: verbal and nonverbal fluency, delayed
alternation performance, tactual maze learning, continuous
recognition of verbal and nonverbal material, delayed recall of a
complex drawing, recognition of faces and houses, and identification
of famous public figures. In some cases, the degree of deficit was
related to the number of ECT received, patients who had been given
more than 50 ECT being significantly worse than those who had
sustained fewer than 50." (Teuber, et al., 1976, P. 76).
This study is one of the most thorough applications of objective
tests to ECT patients; one would like to see it repeated on patients
who had not also sustained surgical brain damage. Yet, it does not
tell us what individual patients knew about themselves before and
after their ECT. This question received a clear answer in the early
1950s.
The Janis Studies. One series of studies, those of Dr. Irving
Janis of Yale University, stands out in the scientific literature on
the effects of ECT on memory for the past (Janis, 1950a; Janis,
1950b; Janis and Astrachan, 1951). Janis, unlike most investigators,
studied patients before as well as after ECT and could, therefore,
determine whether individual patients showed changes. He studied
patients not merely for a few days or weeks following ECT but for up
to 3+ months. Janis did not primarily use artificially devised tests
but actually asked patients about the details of their lives,
covering the following topics: 1) school history, 2) job history, 3)
history of the mental disorder, 4) sexual and marital relationships,
5) family relationships, 6) childhood experiences, 7) miscellaneous,
e.g., details of the layout and furnishing of the home, 8)
outstanding life experiences, e.g., personal failures and troubles,
best and worst experiences of one's life, etc. In these interviews
he pressed patients for minute detail. For example, he asked the
name, location, years of attendance for each school; reasons for
transferring or leaving; names of teachers; subjects failed and
reasons for failure; difficulties with school authorities;
description of the graduation ceremony on the last day of school. In
this way he built up a rich account of personal memories so that he
could compare the amount of detail that was supplied following ECT.
The Janis studies were carefully controlled. For patients who
were to receive ECT, there was another group who matched the shock
patients in age, education, type and degree of illness, and form of
psychotherapy. These control patients were interviewed in the same
detailed way as the shock patients, both initially and at the same
later intervals. In this way Janis could be certain that any losses
in memory he might find would be due to the ECT and not to the
course of the illness or some other unidentified factor. At the end
of the study, Janis asked both the shock and the control patients to
state what they thought the purpose of the interviews was. Their
replies indicated that none of them suspected that the purpose was
to test their memory. They could not have been "faking"
responses to determine the outcome of the study because they did not
suspect that a study was underway.
The shock patients in this study received standard treatment (60
cycle, AC., 3 times/week). The number of shocks was relatively
modest, between 8-27, with an average of 17. No differences were
noted between patients who received different numbers of shocks.
The results of Dr. Janis' study are, in my opinion, conclusive
proof that serious losses of personal memories are caused by ECT and
that the losses persist. Here is an example of what he found. First,
a 38 year old woman before ECT:
Case E. -- A 38 year old female schizophrenic (borderline or
mixed); 10 electroshocks.
Before ECT. (Q. How did your illness begin?)... .About four years
ago, right after I lost my child ... I took thyroid then which
caused palpitations. I didn't know , At the time, that that caused
it. I felt terrified by them. It was a real panic, as if I were on
railroad tracks with a train coming. I was trying to be very brave
about the death of my baby, going to work in the hospital where it
died, collecting legal papers on it, and so forth, trying to be the
super-woman. Then I had the palpitations; a friend told me I should
get psychiatric help. I saw my family doctor and he sent for a
neurologist. I spent the night at my doctor's office and then I went
to the H Sanitarium for a week. I was hopeful of getting all better.
They didn't feel I was really ill. After that, I began analysis.
(Janis, 1950a.)
Note that a single question elicits a long account that is rich
in detail. Information flows without prompting by the interviewer.
Here is the same woman 3 1/2 weeks after a series of 10 shocks
Three and One-Half Weeks after ECT.
Q.Did you take some medication after the loss of your child? A.I
don't remember. Q.Thyroid? A.I think so. Q.What reaction did you
have to it? A.I don't know. Q.During that period did you have any
special symptom -which disturbed you: A.I felt depressed. Q.Anything
else? A.l don't recall. Q.Did you have palpitations? A.I vaguely
remember having palpitations now that you mention it. Q.How did you
feel about them at the time? A.I don't recall how I felt. Q.How did
you feel at the moment when you had the palpitations? A. Probably
not too well. Q.Did you ever go to a sanitarium? A.Yes, I remember
going to one. Q.What was the name of it? A.I don't recall the name.
Q.What were the circumstances that led to your going there? A.I
don't remember why I went or what happened, I remember being there
though. Q.How long were you there? A.I don't remember. I don't think
it was for very long. I really can't reconstruct that-whole period.
(Janis, 1950a, pp. 369-370.)
Note I hat the woman has many gaps in her recall and needs
specific prompting by the interviewer. Sometimes she recalls facts
when prompted ("now that you mention it ...."). Dr. Janis
gives several additional detailed examples and summarizes as
follows:
...the examples fail to convey the extensiveness and variety of
personal experiences subject to amnesia in each individual case.
Every one of the 19 patients included in the study showed at least
several instances of amnesia and in many cases there were from ten
to twenty life experiences which the patient could not recall .
(Janis, 1950a.)
In contrast, the control patients were able to reproduce
practically all the material they had given in the initial
interview, and they recalled it so readily that the examiner rarely
needed to resort to raising questions giving specific cues so often
required by the ECT patients. In fact, most of the control patients
improved between the tests, as one would have expected because of
the stimulation of "reliving" old events (Janis and
Astrachan, 1951). Janis discovered amnesias in patients diverse in
personality type and intellectual status, in patients with different
types of mental disorders, in patients who improved psychologically,
and in those who did not improve. These amnesias were in some
instances for emotionally upsetting material, e.g., related to the
illness, but in other instances were for emotionally
"neutral" material as well. Furthermore, Janis notes,
"many patients were distressed about their failure to recall
past experiences and frequently made definite efforts to secure
information about the events for which they were amnesic". He
says, "The patients usually expressed little conviction about
the occurrence of such experiences and were unable to reconstruct
the details beyond what they had been told about it." (Janis,
1950a, P. 376). Janis notes that there was no tendency for patients
to "protect" their amnesias since they sometimes actively
sought for cues to help them remember. Therefore, even strong
motivation to remember did not help.
A later study employing a somewhat different set of questions
revealed "gross amnesic gaps" such as total failures to
recall a particular job. Again, there were also more subtle amnesias
such as failure to recall details of a specific event. Janis found,
in addition to the gross gaps and subtle losses, a slowness and a
great effort in recalling details. In some cases, details returned,
but only with great effort and with the help of cues provided by the
examine, (Janis and Astrachan, 1951). In his published papers, Janis
reports following half of the shocked patients for 2 1/2 - 3 1/2
months after the end of ECT. He found that in each case most of the
instances of amnesia persisted. Janis continued to follow six of
these patients for a full year and found that the amnesias persisted
(Janis, 1976).
The Janis studies employed the most sensitive method of any in
the literature and the one that most directly addresses the concern
of the patients, the loss of their own memories of their pasts. It
would seem to me incumbent upon any researcher who fails to find
memory loss using an artificially devised test to explain the Janis
results. The simplest explanation at present is that the artificial
tests are not as sensitive. No author so far has mounted serious
criticism of the Janis studies, nor has anyone repeated them. The
Janis results fit well with the evidence cited earlier that ECT
causes organic brain damage. Overall, the evidence convinces me that
ECT is far from benign. If, for others, doubts remain as to whether
ECT impairs human memory, the first step toward settling the issue
should be a careful and thorough repetition of the Janis studies.
OVERALL CONCLUSIONS 1.Convulsions caused by electrical shocks to
the brain are accompanied by alterations within the brain. Many of
the brain's natural protections are broken down. Mentioned in
particular are the massive rise in blood pressure, the breakdown of
cerebral auto regulation of blood flow, and the breakdown of the
blood-brain barrier.
2.Such changes can lead to alterations in brain chemistry and
physiology. The change most easily measured in humans is the
alteration of the EEG toward a form that is commonly recognized as
pathological.
3. Such changes are also associated in many studies with gross
pathology such as brain swelling (edema) and particularly brain
hemorrhages which lead to the irreversible death of neurons.
4. Such changes are also associated with persisting, probably
permanent amnesias for life events and experiences.
5. Such amnesias may only be detected when patients are
questioned in detail about their life histories before and following
the administration of shocks.
6. At all levels, from changes in blood pressure to losses in
memory, there is extreme variability. Losses can, however, be
catastrophic after only a few shocks. In general, the younger and
healthier the animal or person, the less permanent damage may
result.
7. Such losses of memory can and do occur without any necessary
changes in overall intelligence as measured by a psychological test
and without any other detectable neurological abnormalities. This
finding is common not only with ECT but in brain damage accompanying
other kinds of insult such as trauma or toxicity.
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