REVIEW  
Niger J Paed 2015; 42 (2): 80 –82  
Asindi AA  
Autonomic manifestations of  
epilepsy  
DOI:http://dx.doi.org/10.4314/njp.v42i2.1  
Accepted: 26th February 2015  
Abstract: An epileptic fit does  
not only manifest as bizarre motor  
activity but can destabilize auto-  
nomic functions. Abnormal elec-  
trical discharge originating from  
the cerebral cortex can spreads to  
involve the autonomic system  
thus creating a dysfunction of the  
sympathetic and the parasympa-  
thetic which modulate the cardio-  
respiratory, digestive, genitouri-  
nary systems. The autonomic  
phenomenon can be encountered  
in simple partial, complex partial,  
generalised tonic-clonic, absence  
and generalized tonic seizures.  
Both the motor and the autonomic  
components may manifest simul-  
taneously; at times the autonomic  
symptoms may precede or outlast  
the motor components. Auto-  
nomic features affecting the car-  
diopulmonary function may be  
life-threatening and contributes to  
apnoea, atrial fibrillation, sinus  
arrhythmias, atrial and ventricular  
premature depolarisations, bundle  
branch block and asystole are  
known to manifest in the peri-ictal  
and also in interictal phases of  
epilepsy. Poor control, and poly-  
therapy in the management of pa-  
tients, render some epileptics more  
vulnerable toexcessive excitability  
of the autonomic nervous system.  
The aim of this communication,  
therefore, is to alert and remind  
healthcare givers on the autonomic  
phenomena of epileptic fits some  
of which may result in sudden un-  
expected death. Clinician should  
always take a holistic approach in  
the evaluation of epilepsy patients  
and watch out especially for car-  
diorespiratory variability during  
and in-between attacks.  
Asindi AA (  
)
Neurology Unit, Department of  
Paediatrics,  
College of Medical Sciences,  
University of Calabar, Nigeria.  
Email: asindi.asindi@yahoo.com  
Key Words: Epilepsy, Autonomic  
8
-17% of deaths in individuals  
dysfunction.  
with epilepsy. Hypoventilation,  
Introduction  
temperature, the alimentary system and genitourinary  
functions. Other functions include pupillary changes and  
lacrimation. The sympathetic division provides more  
general control over the entire organism, whereas the  
parasympathetic division regulates local functions more  
precisely.  
Epilepsy is an established tendency to recurrent unpro-  
voked seizures due to an abnormal discharge from brain  
cells. The neuronal discharge can manifest as abnormal  
motor activity, behavioural anomalies, sensory distur-  
bances and impaired consciousness. This electrical ac-  
tivity can also spread to involve central centres for the  
regulation of autonomic activity in the individual.  
During a seizure episode, electrical activity arising from  
the cortex spreads through the limbic system with in-  
volvement of the amygdala, hippocampus, thalamus and  
hypothalamus. This in turn is propagated to involve the  
autonomic nervous system(ANS) nuclei in the brain  
stem from where the sympathetic and parasympathetic  
The cardiovascular changes during the ictal and postictal  
phases of seizure attack have been a regular area of re-  
2
search. With the use of polygraphic studies, Van Buren  
was the first to evaluate the autonomic changes in ac-  
tively convulsing patients by simultaneously recording  
EEG, ECG, pulse oximetry and blood pressures. He also  
recorded respiratory movements, skin temperature and  
resistance, oesophageal and gastric pressures. Neuro-  
physiology methodology has also been developed to  
evaluate the regulation of sweating, bladder function,  
erectile function, gastrointestinal tract motility and pu-  
pillary reactions during seizures.  
Autonomic symptoms can occur in the ictal, postictal,  
and even during the interictal phases of epilepsy. In  
some instances, the autonomic phenomena may consti-  
tute the initial seizure manifestation. In a number of  
cases, the autonomic manifestation such as tachycardia  
may precede the ictal manifestations, and bradycardia  
1
efferent discharges are then generated . The cranial  
nerves involved are III, VII, XI and X.  
The autonomic nervous system(ANS) is divided into  
sympathetic and parasympathetic divisions both of  
which are important in maintaining homeostatic func-  
tions. The cerebral cortex influences these divisions  
largely through the hypothalamus. Both the sympathetic  
and the parasympathetic function independently to  
maintain the blood pressure, heart rate, and blood flow;  
activate the sweat and salivary glands; regulate body  
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may linger into the postictal phase . The interictal  
phase in epilepsy is the interval between active seizures.  
During this seizure-free period, which may last weeks or  
months, the EEG of more than 80% of epileptics con-  
tinue to show spikes wave pattern. This indicates an on-  
going electrical emission from the cerebral hemisphere  
which can secondarily excite the autonomic centres thus  
causing active sympathetic and parasympathetic mani-  
festations without any concomitant motor component.  
This phenomenon, which may even carry a risk of sud-  
den and unexpected death from cardiorespiratory dys-  
Gastrointestinal manifestations  
Abdominal pain is a very common complaint in chil-  
dren, and may be a forerunner of an impending motor  
manifestation. This could be accompanied with nausea,  
vomiting and faecal incontinence.  
Genitourinary symptoms  
Urinary incontinence is frequent in generalised tonic-  
clonic fits due to bladder muscle contraction and exter-  
nal sphincter relaxation. Erotic feeling, sexual arousal,  
erection and orgasm are reported. All these arise as a  
consequence of involvement of the limbic system and  
the temporal cortex.  
3
function, occurs both in adults and children .  
The propagation of the hypersynchronized electrical  
impulse to autonomic centres can occur in simple par-  
tial, complex partial, generalised tonic-clonic, absence  
and generalized tonic seizures. Autonomic symptoms  
accompany all generalised tonic-clonic seizures and one  
Skin, secretory gland and eye involvement  
1
third of simple partial seizure . Patients with epilepsy-  
have a mortality rate that is 2-3 times that of the general  
population which is deaths, largely due to autonomic  
involvement .  
The autonomic aspect of epilepsy appears to be an area  
of minimal interest and emphasis to clinicians hence the  
aim of this communication which is to bring to the fore  
anin-depth knowledge, particularly the dangers related  
to this subject. With this awareness, clinicians will be  
expected to holistically evaluate the epileptics under  
their care and institute appropriate measures.  
During an episode of generalised tonic-clonic seizure,  
excessive sweating, salivation and lacrimation can oc-  
cur. Flushing, erythema, blanching, pallor and piloerec-  
tion can follow complex partial seizure of temporal lobe  
origin. Pupillary dysfunction can be bilateral or unilat-  
eral manifesting as mydriasis or miosis.  
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Sudden unexpected death in epilepsy (SUDEP)  
SUDEP is defined as sudden, unexpected, witnessed or  
unwitnessed, nontraumatic and nondrowning death in a  
patient with epilepsy, with or without evidence of a sei-  
Cardiovascular manifestation in epilepsy  
6
zure and excluding status epilepticus . Autopsy in this  
condition does not reveal an anatomical or toxicological  
With simultaneous EEG and ECG recordings, several  
observations have been documented on the cardiac  
manifestations of patients with unprovoked seizures.  
Palpitations, chest pain, tachycardia, bradycardia, ar-  
rhythmia, hypotension, hypertension can be detected.  
Seizure related bradycardia followed by tachycardia can  
occur in patient with absence and generalised tonic-  
clonic attacks. Rhythm and conduction abnormalities  
have been reported in patients with partial seizures. This  
cardiovascular phenomena are prevalent when the pri-  
mary foci is in the mesial temporal region of the brain.  
cause of death. This condition is not rare; it contributes  
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-17% of deaths in people with epilepsy . The average  
age for SUDEP is 28- 35 years but has also been re-  
7
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ported in children . Various pathophysiologic events  
contribute to SUDEP. These include central apnoea,  
neurogenic pulmonary oedema and airway obstruction;  
others are cardiac arrhythmias leading to acute cardiac  
failure and arrest. Cardiac arrhythmias, during the ictal  
and interictal periods, leading to acute cardiac failure  
may contribute significantly to SUDEP. Death is not  
usually as a direct result of a seizure or status epilepticus  
but occurs suddenly during normal or benign circum-  
stances. In a majority of cases, patients had had a seizure  
immediately before death. In all witnessed deaths, sei-  
zure had stopped before death, and in many cases, the  
patient had even regained full consciousness before  
5
Mayer et al recorded tachycardia in 98% of children  
suffering from complex partial seizures of temporal lobe  
origin. Rhythm aberrations may include atrial fibrilla-  
tion, sinus arrhythmias, atrial and ventricular premature  
depolarisations, bundle branch block and asystole.  
9
,10,11  
.
death  
Effect on the respiratory system  
Evaluation of autonomic cardiovascular reflexes in pa-  
tients with epilepsies indicates dysfunction of both the  
sympathetic and parasympathetic components. Repeti-  
tive exposure to catecholamines during fits is known to  
cause myocardial fibrosis. These fibrotic areas act as  
foci for cardiac arrhythmias. Autopsies following death  
from SUDEP have demonstrated fibro2,s1i3s of the cardiac  
Hyperventilation, cough, hypoventilation, apnoea and  
cyanosis have been documented during epileptic attacks  
of generalised tonic-clonic type and with fits arising  
from the temporal lobe. Since the cardiomodulatory cen-  
tres and the respiratory control centres are closely linked  
at the brainstem level, the cardiac and respiratory im-  
pairment can occur simultaneously. It is pertinent to  
note that in some patients presenting with recurrent  
autonomic events, a seizure may be the underlying pri-  
mary pathology. For example, apnoeic attacks, cyanosis  
and heart rate variations are well known features of neo-  
natal seizures which may not be apparent otherwise.  
1
conducting system in some patients. Poor control of  
epilepsy, and polytherapy in the management of patients  
render some epileptics vulnerable to SUDEP. Frequent  
and potentially fatal asystole is an indication for a per-  
manent pacemaker insertion to avoid sudden  
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unexpected death.  
Felbamate can cause gastrointestinal disturbances. How-  
ever, studies have shown that patients on antiepileptic  
drugs tend to have less impaired regulation of the auto-  
nomic cardiovascular ref5lexes compared with patients  
Some differential diagnosis of autonomic phenomena  
1
The pathophysiology of syncope involves bradycardia,  
arrhythmia, hypotension and asystole which are also  
encountered in the autonomic reflexes of epileptic fits.  
Where a clear distinction cannot be made between con-  
vulsion and syncope, ineffective and dangerous thera-  
peutic measures may be applied. Syncope is primarily a  
cardiovascular event involving a 20% reduction or an  
abrupt cessation of blood flow to the brain. Contrast-  
ingly, a seizure can occur in a patient adopting any pos-  
ture whereas syncope usually occurs in individuals  
while in an upright position. Syncope manifests with  
dizziness, light headedness, dimming vision before un-  
consciousness; consciousness is regained shortly after  
resuming a supine position. Very rarely, a patient with a  
prolonged syncopal attack may exhibit myoclonic jerks,  
tonic 4spasms and urinary incontinence during the  
who are not on treatment .  
Conclusion  
It is pertinent that clinicians should not lack depth in  
understanding the link between epilepsy and the auto-  
nomic reflexes so that the variability in clinical manifes-  
tations can be appropriately identified and appropriately  
managed. When epileptic attacks are well controlled, the  
autonomic reflexes are less prominent. In the event of  
cardiorespiratory compromise the administration of oxy-  
gen, use of CPAP and vagal stimulation may suffice.  
With repeated threats of bradycardias and asystoles, a  
pacemaker introduction becomes inevitable. Whereby a  
particular antiepileptic medication constitutes autonomic  
1
event .  
-related cardiovascular or respiratory risk, such an of-  
Some antiepileptic drugs can negatively impact on the  
autonomic nervous system. Arrhythmias, hypotension  
and respiratory depression have been recorded with car-  
bamazepine, lorazepam, phenobabitone and phenytoin  
medication. Sodium valproate, Ethosuximide and  
fending drug needs be replaced. A proper control of sei-  
zures with monotherapy is the hallmark in the preven-  
tion of SUDEP.  
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