Basic Mechanism and Genetics

Epileptic seizures are caused by abnormal, repetitive firing of neurons. Although multiple etiologies may result in these discharges, it is believed that three key elements are con tributory: neuronal membrane and ion channel characteristics; reduced action of the inhibitory neurotransmitter γ-aminobutyric acid (GABA); and increased excitation through excitatory circuits through glutamate or other excitatory neurotransmitters.^9,10 Absence seizures are believed to involve an abnormality in the circuitry between the thalamus and the cerebral cortex.¹¹

Certain epileptic syndromes, both partial and generalized, follow single gene mendelian inheritance genetics. Since 1995, genetic discoveries have linked idiopathic epilepsies to mutations of voltage-gated channels, ligand-gated ion channels, and neurotransmitter receptors.¹² Many other epilep-sies with genetic predispositions are likely due to complex multiple-gene inheritance patterns, and targeted pharmacological strategies have not yet emerged from these findings.

Pathology

Although the etiology of epilepsies is diverse, several neuropathological substrates deserve attention.

Hippocampal sclerosis is the most common cause of recurrent partial epilepsy in adults. This is characterized macroscopically by shrinkage and induration, and histopathologically by pyramidal neuron loss and gliosis, most severely found in certain subregions of the hippocampus.¹³ Hippocampal sclerosis can be seen on magnetic resonance imaging (MRI) scans, and the presence of this abnormality portends good outcomes after epilepsy surgery in patients with temporal lobe epilepsy (TLE).

Malformation of cortical development is the most common structural pathological abnormality seen in pediatric epilepsy. Malformation may occur during neuroglial proliferation (e.g., as in cortical dysplasia), migration (heterotopia), or organization (polymicrogyria) of the cortex.¹⁴ These conditions are frequently associated with severe seizures and with developmental delays.

Classification of Seizures

The ILAE broadly classifies epileptic seizures into two groups (Table 76-1)¹⁵: focal (partial) seizures (i.e., those with an initial onset limited to one part of the brain); and generalized seizures (i.e., those with no discernible focus of onset). A third category consists of seizures that cannot be classified in these two categories.

Table 76-1 Clinical and Electroencephalographic Classification of Epileptic Seizures

Generalized Seizures

Although there are multiple distinct types of generalized seizures, seizures are usually classified into three major groups: major motor seizures, absence seizures, and minor motor seizures.

Generalized tonic-clonic (GTC) seizures (also called “grand mal,” generalized convulsive, or major motor seizures) are the most common type of generalized seizure; they also occur when a partial seizure becomes secondarily generalized.

In a purely GTC seizure, the first component is a loss of consciousness; the patient will be unaware of what has happened. The second component is the tonic stage, characterized by contraction of the skeletal muscles, extension of the axial musculature, upward deviation of the eyes, and paralysis of the respiratory muscles due to thoracoabdominal contractions. This stage is brief, ranging from only about 3 seconds to a maximum of 30 seconds, although it may seem longer because of its dramatic appearance. The most striking feature is extension of the upper and lower extremities into a semi-opisthotonic posture. Sudden spasm of the respiratory muscles results in forced exhalation that may sound like a scream, the so-called epileptic cry. Although contraction of the respiratory muscles causes the patient to stop breathing, it is not a cause for concern, since the tonic stage lasts only a few seconds.

As the muscles of mastication go into spasm, the patient may bite down hard. Tongue biting is seen frequently, but contrary to popular belief, the patient will not swallow his or her tongue, so objects such as a spoon or tongue depressor should not be inserted forcefully into the patient’s mouth. In the young patient, this action could also dislodge a loose tooth, which could be aspirated.

Eye movements that occur during the tonic stage can provide clues as to the nature of the seizure. In a generalized seizure, the eyes deviate directly upward, whereas in focal seizures, particularly those involving the frontal eye fields, the eyes deviate to the side contralateral to the lesion or focus. The direction of eye movement does not reliably lateralize in temporal seizures.

Once the tonic stage ends, the patient enters the clonic phase, which is characterized by rhythmic jerking movements. Clonic movements have a high amplitude and a low frequency, unlike myoclonic movements, which are very brief, or tremors, which have a low amplitude and high frequency. In a generalized seizure, clonic movements are symmetrical, with the arms and legs moving in unison. Clonic arm movements generally have greater amplitude than clonic leg movements, and the trunk is usually uninvolved.

The clonic stage generally lasts between 3 and 7 minutes, after which time the patient is usually conscious, but confused. If after 7 minutes the patient either does not wake up or has another seizure, the diagnosis of status epilepticus should be considered.

GTC seizures are also characterized by symptoms involving the autonomic nervous system. Hippus, in which the pupils alternately contract and dilate in a rhythmic pattern, is common, but occasionally the pupils may either contract or dilate. It is often useful to examine the pupils during a seizure, even in a patient on a respirator, since hippus can be a sign of seizures. Other common autonomic signs include changes in facial color (to either pallid or flushed), excessive salivation (to the point of drooling), increased heart rate and blood pressure, increasing intravesicular pressure, and relaxation of the urinary and anal sphincters (resulting in incontinence or defecation).

Once a patient regains consciousness after a GTC, he or she enters the postictal period in which he or she typically falls asleep for up to several hours and wakes up with a headache.

Absence (“petit mal”) seizures are another form of generalized seizures. Absence seizures occur mainly during childhood and are less frequent after puberty. They are characterized by the arrest or suspension of consciousness for 5 to 10 seconds. Parents may not notice the typical brief seizures in an otherwise healthy child, but teachers will report that the child stares absently for short intervals throughout the day. Without treatment, absence seizures may occur up to 70 to 100 times a day, and such frequent blackouts can seriously impair a child’s school performance. The physician can usually confirm the diagnosis by asking the child to hyperventilate, since this maneuver will precipitate an attack. Other signs include rhythmic blinking (at a rate of 3 blinks per second) and rudimentary motor behaviors, called automatisms, which also occur in adult TLE. Absence seizures are the easiest seizure disorder to diagnose because of its pathognomic EEG (a spike-and-wave pattern that occurs at a frequency of 3 cycles per second), especially when the child hyperventilates.

Minor motor seizures most commonly involve myoclonic and akinetic seizures. Although these seizures usually occur in childhood, adults may experience them.

Myoclonic seizures are characterized by sudden, brief muscular contractions that may occur singly or repetitively. Myoclonic seizures may be present in devastating childhood epileptic syndromes, such as West syndrome, which is often accompanied by developmental delay. Myoclonic seizures may also occur in adolescents with gray matter disease and in adults with infections, such as viral encephalitis, and with prion disease. Myoclonic seizures may also occur in association with dialysis dementia and after severe hypoxic ischemic brain damage that has resulted from a cardiac arrest.

Unlike myoclonic seizures, akinetic seizures are characterized by a loss of muscle tone. The appearance depends on the muscles affected. “Head bobbing” occurs if the neck loses muscle tone, “bending seizures” occur if the upper extremities are affected, and “drop attacks” occur if the lower extremities are involved. However, it is much more common for children to faint than to have akinetic seizures. Although not diagnostic, the EEG is often helpful in identifying akinetic seizures. A typical EEG pattern consists of slow spikes and waves (or polyspikes and waves), even during the periods between seizures.

Partial Seizures

Partial seizures follow Jackson’s focal model of epilepsy and are frequently associated with brain lesions. Surprisingly, partial seizures may also be the result of single gene mutations to ion channels. These disorders are usually classified as either simple or complex, depending on whether consciousness is affected.

Temporal Lobe Epilepsy

TLE is the most common form of focal epilepsy in adults. Complex partial seizures arise from the mesial temporal region, for example, from the hippocampus, the parahippocampal gyrus, or the amygdala. The most common etiological factor associated with mesial TLE is the occurrence of prolonged febrile convulsions in childhood, which may predate the onset of afebrile seizures by many years.^17,18 Childhood febrile convulsions are relatively common and few patients develop TLE as a result of them. However, prolonged febrile convulsions have been documented in a majority of patients with mesial TLE. The exact mechanism by which prolonged febrile convulsions generate hippocampal sclerosis remains unclear. Chromosomal abnormalities have been found in some familial cases of mesial TLE.¹⁹

Hippocampal atrophy may be seen on high-resolution MRI scans. Positron emission tomography (PET) scans show reduced uptake in radioactive glucose on the side of the pathology. Afflicted patients are often intractable to medical management, but can be effectively treated with surgical resection. Pathology often shows evidence of hippocampal sclerosis (see Pathology).

Idiopathic Generalized Epilepsy

Idiopathic generalized epilepsy (IGE) encompasses a number of specific syndromes that likely overlap each other. Common features among them include generalized seizures (absence, myoclonus, or tonic-clonic seizures), a characteristic EEG pattern (generalized spike-wave discharges), a genetic predisposition, and an otherwise normal neurological development. Although these patients have structurally normal MRI scans, there may be increased amounts of nonspecific abnormalities.²⁰ Childhood absence epilepsy is most commonly seen; brief absence seizures occur, at times with great frequency (up to hundreds a day), starting between ages 4 and 10. They show a characteristic 3-Hz spike-wave discharge on the EEG. They are well controlled with medications. Most but not all patients become seizure-free. On the other hand, juvenile absence epilepsy starts somewhat later, after puberty. Absences are not as frequent, GTC seizures occur more often, and they typically require life-long therapy. The most common IGE is juvenile myoclonic epilepsy in which myoclonic and GTC seizures are the predominant patterns. This syndrome also requires life-long therapy.

Status Epilepticus

Status epilepticus is defined by the ILAE as continuous seizure activity, or two or more seizures without full recovery of consciousness for greater than 30 minutes.²¹ However, the length of a seizure before becoming labeled as status epilepticus has been challenged, and 5 minutes is likely a more clinically relevant time frame.²² The mortality rate in status epilepticus is very high, and as such, it should be considered a true emergency. As such, the ABCs (airway, breathing, and circulation) of emergency management should be emphasized. Immediate treatment consists of administration of intravenous (IV) lorazepam (0.1 mg/kg IV) followed by a loading dose of a medication available in IV form (phenytoin, levetiracetam, phenobarbital, or valproic acid) (Table 76-3). If seizures do not cease, a second agent should be added, and preparation for intubation and subsequent administration of continuous high-dose suppressive agents (e.g., propofol, midazolam, or pentobarbital) as well as monitoring with an EEG should be considered. Neurology consultation will be required in all instances.

Table 76-3 Management of Status Epilepticus

Clinical Examination

The history from the patient and witnesses remains the most important aspect of the evaluation. In order to classify seizure disorders, the physician should carefully question the patient about his or her state of consciousness at the time of the seizure. If the patient remains conscious during the episode, the seizure is classified as simple partial; if the patient has altered consciousness, the seizure is called complex partial. Changes in consciousness provide important clues to the nature of a generalized seizure. Patients invariably lose consciousness during primary generalized seizures, or when a partial seizure spreads and becomes secondarily generalized. The important difference, however, is that in partial seizures the loss of consciousness is preceded by a sensation known as an “aura.” Patients with TLE often describe the feeling that something is rising over the chest toward their throat. An aura may take one of several forms, from sensations of dizziness to attacks of fear and depression. The type of aura may offer a clue to the location of the lesion.

Patients should always be examined after a seizure to detect any evidence of asymmetry (e.g., weakness or twitching that is more pronounced in one arm than in the other). Such evidence would indicate a focal, rather than a generalized, seizure. Although the physical examination is almost always normal, a few signs may provide clues to the diagnosis. Since patients with epilepsy often have a history of brain lesions at an early age, the physician should look for evidence of hemiatrophy. For example, if a patient is asked to place his or her hands palm to palm, you may find that one hand is smaller than the other. In partial complex seizures, the physical expression of an emotional response may be asym metrical (e.g., a smile is almost always one-sided). In about 80% of patients with asymmetrical emotional responses or reflexes, the responsible brain lesion is in the hemisphere opposite the weaker side of the body.

Laboratory Investigations

Laboratory investigation should include screening for metabolic disorders, including hyponatremia, hypokalemia, hypocalcemia, and hypoglycemia, as well as withdrawal from alcohol or from other recreational drugs. If an infectious etiology is suspected, investigation should include blood cultures and a lumbar puncture. The patient’s medications should be carefully tabulated; missed antiseizure medication in an epileptic patient is a common etiology for a seizure. Many other medications (including antidepressants and antibiotics) may lower seizure threshold, and should be discontinued.

Electroencephalogram

All patients with a new seizure or suspected seizure dis-order should obtain an EEG. The sensitivity of an EEG is relatively low (ranging from 30% to 50%) in detecting epileptiform abnormalities on a single EEG, but the yield may be increased (to 80% to 90%) by obtaining multiple EEGs, an ambulatory 24-hour EEG, or a sleep-deprived EEG.^23–26 Hyperventilation and photic stimulation (flashing lights) during the EEG may further increase the yield of the EEG in limited circumstances.

Neuroimaging

MRI is the imaging modality of choice in patients with seizures. In addition to major structural abnormalities (such as brain tumors, abscesses, and strokes), an MRI scan may reveal more subtle structural abnormalities (such as hippocampal volume loss and asymmetry), seen typically in patients with TLE.²⁷ Computed tomography (CT) has a more limited role in patients not suspected of having trauma, intracranial hemorrhage, increased intracranial pressure, or other similar catastrophic etiologies.

Because of difficulties in accurately localizing focal seizures, multiple other imaging modalities are used to complement EEG and MRI scans in patients with a seizure disorder, particularly in patients undergoing surgical evaluation. These include PET,²⁸ single-photon emission computed tomography (SPECT),²⁹ and magnetoencephalography.³⁰

Nonepileptic Psychogenic Seizures

Nonepileptic psychogenic seizures (“pseudoseizures,” “psychogenic seizures”) represent a large and challenging subgroup of patients evaluated for a seizure disorder. They may represent up to 30% of patients with seizures refractory to traditional antiseizure medications.³¹ Most frequently, these seizures are a form of conversion disorder in which the patient produces these seizures without conscious effort and without an obvious secondary gain. Patients with nonepileptic psychogenic seizures frequently have an antecedent history of sexual or other psychological trauma,^32,33 and they are much more likely to be female.³⁴

Although preexisting risk factors and description of seizures (such as pelvic thrusting³⁴) can be helpful in raising suspicion of a nonepileptic psychogenic seizures, conclusive diagnosis usually requires the use of video-EEG monitoring during which a typical episode is captured. Hyperkinetic frontal lobe seizures may mimic nonepileptic psychomotor seizures,³⁵ leading to substantial difficulties in reaching the correct diagnosis in a small portion of patients.

Although excellent outcomes have anecdotally been reported if an underlying psychiatric conflict can be identified and resolved, these are often difficult to identify, and no definitive treatment exists for this condition. More than 70% of patients continue to have seizures chronically,^32,36 a considerably higher rate than with patients with epileptic seizures. Unlike prevailing beliefs, the number of patients with nonepileptic psychogenic seizures and epileptic seizures is low.³⁷

Other Conditions Mimicking Seizures

A variety of other paroxysmal disorders may mimic seizures. Syncope may induce transient cerebral hypoxia and may produce seizure-like activity (such as myoclonic jerks, head turns, and automatisms) in more than 10% of patients.^38–40 Syncopal attacks are more often associated with feelings of light-headedness, sweating, and nausea, and are seen after prolonged periods of standing.³⁸ Although syncopal attacks are relatively benign, especially in young individuals, additional testing, including a cardiac evaluation, should be strongly considered.

Migrainous phenomena may often mimic seizures in that they may be manifest as auras of visual disturbances, vertigo, migrating paresthesias, and other sensory disturbances, and speech difficulties, all of which may also be seen in partial seizures. These migraines may occur without headaches; rarely, a migraine may evolve into a seizure.⁴¹ Panic disorder may frequently mimic simple autonomic seizures. Common symptoms of autonomic arousal include nausea, tachycardia, hyperventilation, palpitations, and shaking. Panic attacks typically last longer than simple autonomic seizures. Features of sleep disorders (such as cataplexy and hypnagogic hallucinations in narcolepsy, bizarre behaviors in parasomnias, and periodic limb movement disorders) may readily be mistaken for seizure disorders.⁴²

Historical Notes

Perhaps the first description of an authentic treatment for epilepsy appeared in the book of Mark in the New Testament. Mark described how Jesus advised a man with falling sickness (epilepsy) to pray for 3 days. For Jesus, prayer also implied fasting. When the man prayed and fasted for 3 days, he naturally developed ketosis, which stopped his seizures. Physicians now recognize that a “ketogenic diet” (i.e., a diet high in saturated fats, such as butter and cream) is one of the most effective ways to halt myoclonic and akinetic seizures. Thus, Jesus might be considered the world’s first epileptologist.

Despite this promising beginning nearly 2,000 years ago, the treatment of seizure disorders remained in the “Dark Ages” until relatively recently. The dramatic seizures and interictal behavioral changes, which are seen particularly in patients with complex partial seizures, may account for the fear and superstitions that have impeded the scientific study of epilepsy.

Initially, bromides were used by Sir Charles Lockock to treat catamenial disorders, including epilepsy. In the early twentieth century, physicians first recognized the anticonvulsant effects of phenobarbital and, later, of other barbiturates. Phenytoin was introduced the 1930s, and carbamazepine and valproic acid in the 1970s. These are considered to be the “classical” antiepileptic drugs (AEDs). Felbamate was introduced 1993 with rapid subsequent introduction of a variety of effective AEDs, ushering in a new era of “modern” antiepileptic drugs.

Medical Treatment Consideration

The most commonly used antiepileptic drugs are summarized on Table 76-4. The modern AEDs are not believed to be more efficacious in comparison to the “classical” AEDs, but they are likely better tolerated⁴³; recent evidence suggests that the modern agents may be superior in some instances,⁴⁴ while the “classical” drugs are preferable in other conditions.⁴⁵

Among the modern medications, only oxcarbazepine, lamotrigine, and topiramate have been approved for monotherapy for patients with intractable partial seizures; the others have been approved only as adjunctive therapies. However, this should not hinder the physician from using any of the other medications as monotherapy; although this discrepancy exists because monotherapy trials were not done with certain medications, there is no evidence that these “off-label” medications are less effective than the “approved” medications in monotherapy.

Basic treatment generally involves starting monotherapy with an AED and increasing its dosage until seizures are controlled or side effects become intolerable. If this occurs, monotherapy with a second medication should be considered; thereafter, a third medication or a combination of two should be considered. In most instances where medications will be effective, control will be achieved by the first or second medication initiated.⁴⁶

The selection of AEDs, given the myriad of choices today, depends on multiple factors; it is not amenable to a dogmatic schema. Sometimes, one medication is clearly superior for a known seizure type (such as valproic acid for primary generalized seizures). Sometimes, an AED may aid in the treatment of concurrent medical conditions (such as lamotrigine for concurrent mood disorder or topiramate for headaches). More frequently, the effects of concurrent medical conditions (such as pregnancy or hepatic/renal failure) and the AEDs, as well as medication interactions, should be carefully evaluated (particularly in patients on chemotherapy). In patients who have had side effects (such as skin rashes or other allergic reactions to AEDs), the physician should select an AED with a more preferable side-effect profile.⁴⁷ Especially with use of benzodiazepines, the addictive potential of an AED needs to monitored.

Surgery

Surgical management of epilepsy represents the only option for a cure for the 35% of patients with epilepsy who are intractable to medications.⁴⁶ The greatest success has been achieved in patients with mesial TLE. A meta-analysis of these patients showed that two-thirds of patients were free of disabling seizures, and 85% had improved after surgery.⁴⁸ A study that randomized patients for medical and surgical treatment revealed that patients who underwent surgery had both better control of their seizures and a better quality of life.⁴⁹ Because of potential adverse effects on language and memory, and visual fields, in addition to the usual risks of vascular problems and infections, patients are carefully and thoroughly investigated by a multidisciplinary team involving neurologists, neurosurgeons, radiologists, neuropsychologists, and psychiatrists. In addition to the previously stated neuroimaging studies and standard EEGs, patients undergo an additional intracarotid sodium amytal (“Wada”) test,⁵⁰ neuropsychological assessment, implantation with intracranial leads, and functional neuroimaging.

Surgery for extratemporal lobe epilepsy has been more challenging. Because the finding of a structural lesion is highly predictive of surgical success, neuroimaging has had a disproportionate importance in the evaluation of these patients. Even subtle cortical dysplasias may underlie refractory epilepsy or status epilepticus.^51,52 More drastic surgeries (such as hemispherectomies or corpus callosotomies) may be performed for either curative or palliative purposes in severe epilepsy.

Vagus Nerve Stimulation

Although a relatively novel tool in the armamentarium of epileptologists, the antiepileptic effects of vagal nerve stimulation (VNS) have been known since the nineteenth century.⁵³ VNS consists of a battery-powered coin-sized generator implanted in the chest that transmits pulses of electricity at regular intervals to the vagus nerve. The patient may provide additional stimulation at higher power with a hand-held magnetic device. Clinical trials have demonstrated that seizure frequency is reduced by at least 50% in up to one-third of patients.⁵⁴ Contrary to use of medications, the effectiveness of the VNS appears to increase with time.^55,56 However, few patients become seizure-free solely with VNS. Serious side effects are relatively rare, and common side effects (such as voice alterations) are well tolerated. Unlike the effects of medications, cognitive side effects of VNS are nonexistent. Some studies have shown that VNS is also effective for treatment-resistant depression.⁵⁷

Depression

Depression is the most common co-existing psychiatric disturbance in patients with epilepsy, affecting up to 30% of patients, and likely a higher percentage in those with uncontrolled epilepsy.^58,59 In patients with TLE, postictal depression that lasts for hours or days may occur.⁶⁰ Transient postsurgical depression is seen in nearly half of patients undergoing temporal lobectomy.⁶¹ Depression occurs more commonly in patients with epilepsy than in neurologically normal subjects, although not necessarily more often than in persons with chronic neurological disease. More surprisingly, though, depression appears to be a risk factor for epilepsy, as studies have shown an increased incidence of depression before a first seizure.⁶² The existence of depression also predicts pharmacoresistance in epilepsy.⁶³ Depression and epilepsy may share common neurobiological substrates (including serotonin, norepinephrine, and dopamine).^62,64 Treatment of co-existing depression must be included in the comprehensive treatment of a seizure disorder.

Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for depression in patients with epilepsy because of their low potential of lowering seizure threshold and the lack of interaction with the AEDs. Neither venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI), nor mirtazapine, a norepinephrine agonist, appears to lower seizure threshold.⁶⁵ Amoxapine, clomipramine, and bupropion should be avoided in patients with epilepsy. Tricyclic antidepressants (TCAs) and buspirone lower seizure threshold at higher doses.⁶⁶

Psychosis

Psychosis may affect up to 7% of patients with epilepsy.⁵⁸ Psychotic symptoms may occur during the ictal, postictal, or interictal phase,⁶⁷ and are a common co-morbidity. Ictal psychosis is a rare phenomenon. Ictal and postictal psychosis are infrequent; a more common form is chronic interictal psychosis. An association of interictal psychosis with TLE has been suggested numerous times, but its relationship has yet to be elucidated. Psychosis related to epilepsy appears to have fewer negative symptoms and is more easily treated. A small number of patients may experience “forced normalization,” which describes the phenomenon in which periods of increased seizure activity alternate with periods of being seizure-free during which the patient has greater psychosis, despite normalization of the EEG.⁶⁸

Certain psychotropic agents may lower the seizure threshold and even generate epileptic spikes on the EEG; these agents (including clozapine, chlorpromazine, and loxapine) should be avoided in patients with epilepsy. Haloperidol may carry the lowest risk of seizures; alternatives also include olanzapine, risperidone, and molindone.⁶⁹ Surgical treatment of patients with TLE and chronic psychosis, with subsequent control of seizures, does not exacerbate psychosis by “forced normalization.”⁷⁰ An adequate history is often sufficient to determine whether seizures and subsequent psychosis are due to chronic psychosis of epileptic disorders, or a manifestation of seizures due to psychotropic drugs.

Anxiety

The prevalence of anxiety in patients with epilepsy is high (ranging from 10% to 50%), but is more difficult to assess.^71,72 Simple partial seizures may manifest as anxiety-like symptoms (e.g., fear and autonomic hyperactivity). Generalized anxiety disorder is most commonly seen in patients with epilepsy during the interictal period. Ideal treatment of interictal anxiety includes both nonpharmacological management (e.g., psychotherapy and stress reduction) and medications (e.g., SSRIs and benzodiazepines).

Memory

Subjective complaints of memory difficulty are a nearly universal complaint in patients with chronic epilepsy. Hippocampal damage is a known consequence of repeated convulsive seizures.⁷³ It is likely that interictal epileptiform discharges detectable on the EEG cause progressive memory problems and cognitive dysfunction in patients with epilepsy.⁷⁴ In addition, patients with chronic epilepsy are prescribed multiple antiepileptic medications, which further contributes to a decline in memory and cognition.

Interictal Personality Changes

Waxman and Geschwind⁷⁵ described the following five personality changes associated with partial complex epilepsy: hypergraphia, hyperreligiosity, hyposexuality, aggressivity, and viscosity. The Russian author Fyodor Dostoyevsky is perhaps the best-known example of an epileptic with hypergraphia, which is the tendency to write prolifically.

Some patients with epilepsy are deeply interested in religion, although not necessarily one of the world’s major religions. In some adult patients, the onset of seizures coincides with a sudden loss of an interest in sex. Since patients rarely volunteer this information, the physician should make a point of asking whether the patient has noticed any change in sexual desire. Some patients with TLE also report a change in their sexual preference.

Aggressivity, the fourth type of personality change associated with epilepsy, is distinct from the automatic aggressive behavior occasionally seen during seizures. Again, patients often do not volunteer information about this type of personality change. If patients are asked about their temper, they may become defensive or evasive. On further questioning, one might learn that they engage in aggressive behavior (such as breaking dishes or throwing objects out of a window).

Finally, some epileptic patients develop a personality trait Waxman and Geschwind⁷⁵ called viscosity, meaning that the patients tend to be “sticky.” Some patients with TLE may call the physician every night, and, once they start talking, they will not stop. These five characteristic personality disturbances provide evidence that brain lesions can cause long-term changes in behavior.