Epilpesy Report: Appendix F
Conceptual Issues
Edgar Cayce, a prominent figure in
the development of the holistic medicine movement in America, insisted that the
etiology of most cases of idiopathic epilepsy could be traced to the peripheral
nervous system, usually to the nerves of the abdomen. He also noted that abdominal
thermal anomalies (especially a cold area on the right side of the abdomen) could
be found in such cases (Cayce, 1934). On the face of it, such a model might seem
ridiculous given the mainstream medical emphasis on the brain as the source of
epileptic seizure disorders. Thus it has become important to look carefully at
Cayce model in light of the historic and modern literature to determine if Cayce’s
approach is even worthy of consideration. The discussion that follows explores
several key conceptual issues relating to the plausibility of an abdominal etiology
and pathophysiology for idiopathic epilepsy. In particular, increasing recognition
of the diagnostic entities called reflex epilepsy and abdominal epilepsy are
supportive of the Cayce model.
Reflex Epilepsy
Reflex epilepsy includes a group of epileptic syndromes in
which seizures are induced by a stimulus. The stimulus may be simple (e.g., visual,
somatosensory, olfactory, auditory) or complex (e.g., eating, thinking, reading).
Most cases of documented reflex epilepsy are diagnosed because the triggering
stimulus is easily identified. The Cayce approach to epilepsy can be characterized
as a broader conceptualization of reflex epilepsy to include visceral stimuli
that are not as obvious as typical reflex seizure precipitants (i.e., visceral
reflex epilepsy).
Visceral symptoms that precede seizures (premonitions) or
occur during the early stages of the seizure itself (aura) are common and suggest
autonomic nervous system (ANS) involvement at some level. Although it is usually
assumed that ANS involvement is an effect of primary central nervous system (CNS)
pathology, some researchers have suggested that ANS involvement may have etiological
significance. Thus, visceral symptoms may be associated with underlying visceral
processes that act as precipitating factors in some cases of epilepsy.
The association of abdominal symptoms with epilepsy has been
recognized for many years. For example, “gastric and intestinal disturbances” were
viewed as primary etiological factors by medical doctors during the late 19th
and early twentieth century (Musser and Kelly, 1912).
“The most common aura is of vague gastric distress, ascending up into the
chest” (Gordon, 1942, p. 610). Thus, visceral symptoms may be associated
with underlying visceral processes that act as precipitating factors in some
cases of epilepsy.
Abdominal Epilepsy
Abdominal epilepsy is diagnosed when the visceral symptoms
predominate. A few papers published in the medical journals during the 1960s
called attention to the abdominal features in epilepsy (Berdichevskii, 1965;
Takei and Nakajima, 1967; Juillard, 1967). Over the past twenty-five years, numerous
researchers and clinicians have reported on various aspects of abdominal epilepsy
(Agrawal et al., 1989; Babb and Eckman, 1972; Bondarenko et al., 1986; Douglas
and White, 1971; Hotta and Fujimoto, 1973; Loar, 1979; Matsuo, 1984; Mitchell
et al., 1983; Moore, 1972; O'Donohoe, 1971; Peppercorn et al., 1978; Peppercorn
and Herzog, 1989; Reimann, 1973; Singhi and Kaur, 1988; Solana de Lope et al.,
1994; Yingkun, 1980; Zarling, 1984). Common clinical features of abdominal epilepsy
include abdominal pain, nausea, bloating, and diarrhea with nervous system manifestations
such as headache, confusion, and syncope (Peppercorn and Herzog, 1989). “Although
its abdominal symptoms may be similar to those of the irritable bowel syndrome,
it may be distinguished from the latter condition by the presence of altered
consciousness during some of the attacks, a tendency toward tiredness after an
attack, and by an abnormal EEG” (Zarling, 1984, p.687). Mitchell et al.
(1983) regard cyclic vomiting as a primary symptom of abdominal epilepsy manifesting
as simple partial seizures. Although abdominal epilepsy is diagnosed most often
in children, the research of Peppercorn and Herzog (1989) suggests that abdominal
epilepsy may be much more common in adults than is generally recognized.
Vagus Nerve Involvement in Epilepsy
The vagal link in epilepsy has received attention with regard
to a surgical procedure in which a pacemaker is implanted on the vagus nerve
in the upper chest. Regular stimulation of the vagus has reduced or eliminated
seizure activity in some treatment-resistant patients (Amar et al., 1998; Lundgren
et al., 1998; Handforth et al., 1998). The therapeutic effect is thought to be
produced by calming "hyperexcited"
nerve cells and reverting brain activity to its normal patterns (Snively et al.,
1998).
The vagus nerve is a primary neural pathway between the viscera
and the brain. It is estimated that 80% of vagal fibers are visceral afferents
carrying impulses from the abdomen to the brain (Davenport, 1978). The effectiveness
of vagus nerve stimulation treatment for epilepsy may be indicative of an interruption
of such a reflex pathway between the viscera and brain. If stimulation of the
peripheral nervous system, in this case the vagus, can reduce seizure activity
in the brain, perhaps pathological irritation of this or other peripheral nerves
may also play a role in the etiology of certain forms of epilepsy. Vagal nerve
stimulation via visceral pathophysiology could be a significant factor in some
cases of epilepsy. This nerve pathway between the abdomen and brain is fits the
description of the abdominal nerve reflexes that produce seizures as documented
in the Cayce readings in Appendix A.
Enteric Nervous System
The gastrointestinal tract is richly innervated. Labeled the
enteric nervous system (ENS or “gut brain”), this branch of the ANS
constitutes about one-third of the body’s total nervous system. British
physiologist Johannis Langley is credited with naming the ENS and recognizing
the its relative independence from the CNS. Focusing on the ganglia of the gut,
Langley believed that they do more than simply relay and distribute information
from the cerebral brain. He was unable to reconcile conceptually the great disparity
between the enormous numbers of neurons [2 X 10 (8)] in the gut and the few hundred
vagus fibers from the cerebral brain, other than to suggest that the nervous
system of the gut was capable of integrative functions independent of the central
nervous system (Wood, 1994). The relationship between the ENS and CNS has been
compared to a computer network with each portion of the network acting as a computer
in constant linkage with the other (Wood, 1994). Disruption or extreme synchronization
of impulses between the ENS and CNS could play a role in the pathophysiology
of one or more subgroups of epilepsy (e.g., abdominal epilepsy or visceral reflex
epilepsy).
Thermographic Assessment of ANS Functioning
Whereas noninvasive assessment of the brain cortex with EEG
is relatively simple, evaluation of the visceral component of the ANS is problematic.
In many respects, assessment of visceral ENS functioning is comparable to measuring
deep structures within the brain that are not accessible via EEG. A possible
solution to the problem of measuring ENS functioning is the use of surface thermography
as a measure of sympathetic nervous system vasomotor activity.
Conceptually, assessment with cutaneous thermography is regarded
as a noninvasive window into sympathetic nervous system (SNS) functioning. SNS
functioning is an important division of autonomic nervous system (ANS) physiology
that is known to be involved in many disease syndromes. Thermographic measurement
of the ANS through its two branches (vasomotor ANS and visceral ENS) represents
a promising means of quantifying this important division of the peripheral nervous
system.
ANS Vasomotor Physiology Implications Of Abdominal Thermographic Anomalies
One of the primary problems in researching the Cayce cold
spot hypothesis is how to explain the underlying physiology that can link abdominal
thermal variations to the etiology or pathophysiology of epilepsy. As discussed
above, the ANS vasomotor system (SNS) represents the leading candidate for connecting
cutaneous thermography to neurologic illness. The following information may help
to elaborate this association:
- Physiology of Systemic Thermal Regulation – Thermography
of biological systems assesses the status of dermal thermoregulatory function.
The hypothalamus is believed to be the primary regulator of core temperature
for body-heat maintenance (Bentzinger, 1969). This is essentially a systemic
process by which the organism coordinates body temperature with internal
(e.g., fever) and external (e.g., room temperature) factors and conditions.
- Vasomotor Physiology – More precise local thermoregulation
within each spinal dermatome may account for changes in dermal temperatures
along the torso and extremities (Simon, 1975). This is generally described
as a vasomotor process by which the sympathetic (SNS) division of the ANS
regulates blood flow by dilating or constricting arterioles and capillaries
within the innervated dermatome. Vasodilation tends to increase dermal temperature
while vasoconstriction has the opposite effect. Thus the hypothalamic systemic
regulation of temperature serves as a background against which location variations
in ANS vasomotor function are manifested. We may have detected such local
ANS vasomotor variations in our epilepsy patients.
- Pathophysiological Implications of ANS Vasomotor Anomalies – Normal
body surface temperatures are essentially symmetrical. Bilateral cutaneous
thermal asymmetries and anomalies are suggestive of ANS vasomotor dysfunction,
unless an identifiable surface feature (such as scar tissue or adhesion)
is present to account for the variation. Likewise thermal anomalies in adjacent
dermatomes are regarded as suggestive of sympathetic neuronal dysfunction
(Korr, 1962). Some theorists maintain that SNS vasomotor function is closely
associated with ANS visceromotor functioning (ENS). Thus thermographic anomalies
may represent a “window on the sympathetic system” (Abernathy,
1988). An inherent ANS dysfunction could help account for the common abdominal/visceral
symptoms within one or more subgroups of epilepsy.
Abdominal Symptomatology As A Window Into the Brain
The concept of using abdominal physiology and symptomatology
as a window into brain pathophysiology in epilepsy has been used by Henkel et.
al. (2002) who quantified the prevalence of abdominal aura in focal epilepsies
(involving specific areas of the brain). The seizures of 491 consecutive patients
with focal epilepsies were prospectively classified using prolonged EEG video
monitoring and MRI scan. Two hundred twenty-three patients (45%) had temporal
lobe epilepsy (TLE); 113 patients (23%) had extratemporal epilepsies; and for
155 (32%) patients, the epilepsy could not be localized to one lobe. Abdominal
auras were more frequent with TLE (117 of 223 patients, 52%) than in extratemporal
epilepsy (13 of 113 patients, 12%, p < 0.0001) and more frequent in mesial
TLE (70 of 110 patients, 64%) than in neocortical TLE (16 of 41 patients, 39%,
p = 0.007). Abdominal auras were followed by ictal oral and manual automatisms
(automotor seizure) in at least one seizure evolution in all patients with TLE
(117 patients, 100%). In contrast, only two patients with extratemporal epilepsy
(2 of 13 patients, 15%, p < 0.0001) had abdominal auras evolving into automotor
seizures. An abdominal aura is associated with TLE with a probability of 73.6%.
The evolution of an abdominal aura into an automotor seizure, however, increases
the probability of TLE to 98.3%. This study is a good example of one of the positive
outcomes that we may be able to achieve by monitoring abdominal symptoms and
physiology for comparison with seizure manifestations.
Treatment Implications
If abdominal/visceral ANS reflexes in epilepsy can be consistently
identified via noninvasive assessment, innovative treatments may be developed
to address this specific pathophysiological pattern. Here are some possibilities:
- Medication – For epilepsy patients with significant abdominal/visceral
features (including vasomotor anomalies) medications that selectively target
the enteric nervous system could play a role in seizure prevention.
- Nonsurgical Vagus Stimulation – Osteopathic physicians have
developed specific techniques to manually stimulate the vagus nerve along
its course in the neck. Such a technique (or a similar effect produced by
an electric vibrator) should be researched to see if such nonsurgical vagus
stimulation could be efficacious in epilepsy. This could be could be especially
helpful in medication-resistant cases where surgical implantation of a vagus
stimulator is being considered. Patients that respond to some extent to nonsurgical
vagus stimulation may be good candidates for the surgical procedure if seizures
are not entirely controlled.
- Ketogenic Diet – Used initially in the 1920's as a treatment
option for patients with intractable epilepsy, the ketogenic diet has seen
increasing use for epilepsy (Kinsman et al., 1992; Swink et al., 1997). The
diet is essentially an extremely high fat diet that is low in carbohydrate
and protein. When consumed on a regular basis the diet produces ketosis that
exerts an anti-epileptic effect. Though the precise mechanism of action is
not completely understood, it is interesting that the location on the abdomen
where Cayce described thermal anomalies is also an area of concentration
for lacteals (lymphatics) that absorb fats from the intestinal tract. Dysfunction
in this process could result in thermal anomalies and reduction of absorption
of fats required for optimal nervous system operation.
- Physiotherapy – Interestingly, Hughlings Jackson described
an epilepsy patient who could sometimes prevent the “march” of
a seizure from the extremities of a limb to the torso by vigorously rubbing
the affected limb above the area manifesting the seizure (Jackson, 1931).
If abdominal/visceral reflexes play a role in the etiology and/or pathophysiology
of some cases of epilepsy, simple, noninvasive forms of physiotherapy may
be helpful in decreasing the frequency and/or severity of seizures. Osteopathic
physicians have claimed success in using OMT (osteopathic manipulative treatment)
in epilepsy by giving spinal and visceral manipulations intended to improve
ANS dysfunction (Hazzard, 1905). Early osteopathic physicians suggested placing
a piece of ice at the base of the skull during the premonition or aura of
a seizure to stop the seizure or lessen its impact (Hazzard, 1905). The Cayce
readings recommend hot abdominal packs and visceral massage to reduce the
frequency of seizures. Conceptually, direct alteration of visceral afferent
input to the CNS may be helpful as a preventative or when visceral premonitions
are noted.
The point of this extended discussion of the conceptual
basis of the Cayce abdominal hypothesis of epilepsy is to suggest that the model
is plausible and worthy of research. The variable thermographic findings that
we have documented in this report require a detailed discussion of Cayce’s
abdominal cold spot hypothesis and our thermographic research results.
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