CHAPTER 7
Seizures (Convulsions, Fits), Adult
Presentation
The patient experiencing seizures may be found in the street, the hospital, or the ED. The patient may complain of an “aura,” feel he is “about to have a seizure,” experience a brief petit mal “absence,” exhibit the repetitive stereotypical behavior of complex partial seizures, display the whole-body tonic stiffness or clonic jerking of generalized (grand mal) seizures, or simply be found in the gradual recovery of the postictal confusion and lethargy. Patients experiencing generalized tonic-clonic seizures can injure themselves, most often by biting the tongue laterally or by having an unprotected fall.
What To Do:
If the patient is having a generalized tonic-clonic seizure, stand by him for a few minutes, until the jerking movements subside, to guard against injury or airway obstruction. Usually, only suctioning or turning the patient on his side is required, but breathing will be uncoordinated until the tonic-clonic phase is over.
Watch the pattern of the seizure for clues to the cause. (Did clonus start in one place and “march” out to the rest of the body? Did the eyes deviate one way throughout the seizure? Was there any staring or focal motor symptoms? Did the whole body participate?) If the seizure is over get a careful description of the event from an eyewitness, if possible.
If the seizure lasts more than 5 minutes or recurs before the patient regains consciousness (status epilepticus), it has overwhelmed the brain’s natural buffers, and drugs should be initiated to stop the seizure. Give 2 to 4 mg of IV lorazepam (Ativan) at 2 mg/min (recommended treatment),
or give 5 to 10 mg of IV diazepam (Valium) at 2 to 5 mg/min,
or give 0.02 mg/kg diazepam rectally (gel or IV form may be used) when IV access cannot be obtained,
or give 5 mg (0.07 mg/kg) of IM midazolam (Versed) when IV access cannot be obtained.
With a prolonged seizure, this treatment should be followed by loading with phenytoin (Dilantin) or fosphenytoin (Cerebyx) to prevent recurrence of seizures. Give phenytoin, 10 to 15 mg/kg IV over 30 minutes—at less than 50 mg/min. (The patient should be on cardiac monitoring during administration, and a Dilantin level should be checked first if the patient is thought to be taking the drug.) Alternatively, give fosphenytoin, 15 to 20 mg/kg IV or IM at a maximum IV rate of 150 mg PE (phenytoin sodium equivalents)/min with an initial maintenance dose of 4 to 6 mg/min. (Although much more expensive than phenytoin, fosphenytoin can be given more quickly over 15 minutes, or, if IV access is absent, this drug can be given IM; it does not have the tissue toxicity of extravasated phenytoin if IV access is questionable.)
Status epilepticus is defined as a generalized tonic-clonic seizure in an adult that lasts more than 5 minutes or intermittent convulsions, without recovery of baseline level of consciousness between seizures.
In all cases of status epilepticus, check the patient’s blood glucose level (especially if he is wearing a “diabetes” MedicAlert bracelet or medallion) by performing a quick finger stick test and administering IV glucose if the level is below normal.
If the patient arrives in the postictal phase, examine thoroughly for injuries and signs of systemic disease that can provoke seizures. Elevated temperature can be a sign of meningitis or encephalitis. Nuchal rigidity strongly suggests either central nervous system (CNS) infection or subarachnoid hemorrhage. Record a complete neurologic examination, the results of which are apt to be bizarre. Repeat the neurologic examination periodically, looking for findings suggestive of focal brain disease.
If the patient is indeed recovering, you may be able to obviate much of the diagnostic workup by waiting until he is lucid enough to give a history. Postictal inability to arouse may last 10 minutes after a generalized tonic-clonic seizure, with confusion typically lasting less than 30 minutes.
If the patient arrives awake and oriented after a presumed seizure, corroborate the history through witness accounts or the presence of injuries, such as a scalp laceration, a bitten tongue, or the presence of urinary or fecal incontinence.
Doubt a generalized tonic-clonic seizure if there is no typical postictal recovery period.
Investigate for alcohol or substance abuse; withdrawal from alcohol, benzodiazepines, or barbiturates can provoke seizures.
If the patient has a history of seizure disorder or is taking anticonvulsant medications, check his records and determine current and past frequency of seizures. Speak to his physician, and find out whether a cause has been determined and what studies have been performed (e.g., CT, MRI, EEG). Look for reasons for this relapse (e.g., poor compliance with medications, infection, ethanol poisoning, or lack of sleep).
If the seizure is clearly related to alcohol withdrawal, give 2 mg of IV lorazepam (Ativan) and ascertain why the patient reduced consumption of alcohol. Reasons for decreasing alcohol consumption may include inability to afford alcohol, suffering from pancreatitis or gastritis causing inability to consume alcohol (requiring further evaluation and treatment), or, the patient may have decided to try to stop drinking, realizing it is bad for him. If the patient is requesting detoxification, he should be supported in this decision both medically and emotionally, and additional recovery resources should be discussed.
If a patient is demonstrating signs of delirium tremens, such as tremors, tachycardia, and hallucinations, withdrawal should be medically supervised and treated with benzodiazepines.
Initial treatment with IV lorazepam has been shown to produce a significant reduction in the risk for recurrent seizures related to alcohol.
Because many alcoholics are malnourished, ED physicians will often presumptively treat alcohol withdrawal symptoms with an IV infusion containing glucose, 100 mg of thiamine, 2 g of magnesium, 1 mg of folic acid, and multivitamins, even though there is no convincing evidence that this regimen is of any true benefit in isolated alcohol withdrawal. However, thiamine has been shown to be beneficial in preventing coma and death as a result of Wernicke encephalopathy in patients presenting with altered mental status. Administration of thiamine and vitamins is inexpensive, and has very few side effects. Given this, it is advisable to treat alcoholic patients presenting with acute delirium for both alcohol withdrawal and thiamine deficiency.
If the seizure is a new event, obtain a serum glucose level (to confirm a rapid bedside test result) as well as serum electrolyte concentrations (sodium, calcium, magnesium), renal function tests, hepatic function tests (if liver impairment is suspected), complete blood cell count (if infection is suspected), and urine toxicology screen (if drugs of abuse are suspected). In women of childbearing age, test for pregnancy.
With new-onset seizures, a brain CT scan should be performed to rule out intracranial hemorrhage, ischemic stroke, or tumor. MRI is the gold standard in evaluating seizure disorders and should be obtained when available.
Lumbar puncture should be performed when fever, persistent altered mental status, or nuchal rigidity indicates a possibility of meningitis or encephalitis. Suspicion of subarachnoid hemorrhage should also prompt lumbar puncture, even when head CT scans are normal. A lumbar puncture should also be performed on immunocompromised patients.
About 50% of all patients with a new onset of seizure require hospitalization. Most of these patients can be identified by abnormalities evident on physical examination, head CT scan, toxicology studies, or the other tests mentioned earlier.
If the patient has an established seizure disorder, blood tests are not routinely needed when the patient has a single breakthrough seizure. Anticonvulsant drug levels should be checked when toxicity or noncompliance is suspected. The dose should be adjusted to keep the level above the breakthrough point. Finding a level below the reported therapeutic range should not prompt a dose increase in a patient who has been seizure free for a prolonged period. Neuroimaging and lumbar puncture are unnecessary unless there are new findings to cause suspicion for tumor, intracranial hemorrhage, or CNS infection.
A neurologist should be consulted before antiepileptic drug treatment is initiated for brief new-onset seizures. Many neurologists think it is in the patient’s best interest to withhold long-term anticonvulsant therapy until a second seizure occurs. The neurologist may want to make a detailed evaluation of the patient and counsel him regarding risk for seizure recurrence, the advantages and disadvantages of anticonvulsant therapy, and the psychosocial effect of another seizure. Patients with a single, brief, uncomplicated seizure, a normal neurologic examination, no comorbidity, and no known structural brain disease need not be started on any antiepileptic drug prior to outpatient referral.
High risk for recurrence is present when there is a history of brain insult, when an EEG demonstrates epileptiform abnormalities, and when MRI demonstrates a structural lesion.
Patients with generalized seizures should be advised to avoid dangerous situations. They should take showers rather than baths, not swim without supervision, and not work at heights. Driving should also be restricted until an appropriate seizure-free period has elapsed, specified 6 to 12 months in most states.
If the neurologist recommends phenytoin loading in a stable awake patient, an acceptable oral regimen can be prescribed. Give 1 g of phenytoin capsules divided into three doses (400 mg, 300 mg, 300 mg) administered at 2-hour intervals.
What Not To Do:
Do not forget to check blood glucose at the bedside.
Do not stick anything in the mouth of a seizing patient. The ubiquitous padded throat sticks may be nice for a patient to hold and to bite on at the first sign of a seizure, but they do nothing to protect the airway and are ineffective when the jaw is clenched.
Do not rush to give IV diazepam to a seizing patient. Most seizures stop within a few minutes. It is diagnostically useful to see how the seizure resolves without medication aid; also, the patient will awaken sooner if he has not been medicated.
Do not wait 30 minutes before initiating anticonvulsant therapy for a patient having a continuous seizure or not awakening between intermittent seizures (old definition of status epilepticus). For practical purposes, a seizure lasting longer than 5 minutes should be treated as generalized convulsive status epilepticus, because a generalized tonic-clonic seizure lasting longer than 5 minutes is unlikely to stop spontaneously.
Be careful not to assume an alcoholic cause. Ethanol abusers sustain more head trauma and seizure disorders than does the population at large.
Do not treat alcohol withdrawal seizures with phenobarbital or phenytoin. Both are ineffective (and unnecessary because the problem is self limiting) and can themselves produce withdrawal seizures.
Do not rule out alcohol withdrawal seizures on the basis of a high serum ethanol level. The patient may actually be withdrawing from an even higher baseline.
Do not be fooled by pseudoseizures. Even patients with genuine epilepsy occasionally fake seizures for various reasons, and an exceptional performer can be convincing. Amateurs may be roused with ammonia or smelling salts, and few can simulate the fluctuating neurologic abnormalities of the postictal state. Probably no one can voluntarily produce the pronounced metabolic acidosis or serum lactate elevation of a grand mal seizure (see Chapter 4).
Do not release a patient who has persistent neurologic abnormalities before a head CT scan or specialty consultation has been obtained.
Do not allow a patient who experienced a seizure to drive home.
Seizures are time-limited paroxysmal events that result from abnormal, involuntary, rhythmic neuronal discharges in the brain. Except for rare instances, seizures are not predictable and can occur at inconvenient, embarrassing, or even dangerous times. Seizures are usually short, lasting less than 5 minutes, but can be preceded by a prodromal phase and followed by a long postictal phase, during which there is a gradual return to baseline.
Seizures have been referred to as either grand mal seizures (convulsive movements) or petit mal seizures (staring without convulsive movements). Currently, more precise terminology is preferred.
Epilepsy is a disease characterized by spontaneous recurrence of unprovoked seizures. Provoked seizures result from transient alterations in brain metabolism in an otherwise normal brain. Some factors that can trigger such seizures are hypoglycemia, hyponatremia, hypocalcemia, alcohol and illicit drug withdrawal, meningitis, encephalitis, stroke, and certain toxins and toxic drugs.
The new terminology for seizures divides them into two classes: generalized seizures and partial seizures. With generalized seizures, there is a complete loss of consciousness at onset of the seizure. Partial seizures are characterized by retention of consciousness, because they begin in a limited brain region. Partial seizures can secondarily generalize.
There are seven types of generalized seizures, which start throughout the entire cortex at the same time and, therefore, cause loss of consciousness. They are the following:
▪ Generalized tonic-clonic (grand mal) seizures with a tonic phase of whole-body stiffening, followed by a clonic phase of repetitive contractions.
▪ Tonic seizures, which consist of only the stiffening phase.
▪ Clonic seizures, which consist of only the repetitive contractions.
▪ Myoclonic seizures, characterized by brief, lightning-like muscular jerks.
▪ Absence (petit mal) seizures, which are manifested as brief (1 to 10 seconds) episodes of staring and unresponsiveness. These seizures, unlike complex partial seizures, are rarely found in adults, are very brief, do not produce postictal confusion, and occur very frequently (up to 100 per day).
▪ Atypical absence seizures, which are similar to absence seizures but last longer and often include more motor involvement.
▪ Atonic seizures, characterized by sudden loss of muscle tone and subsequent falling or dropping to the floor unprotected (drop attacks). These seizures must be differentiated from syncope. (see Chapter 11).
Partial seizures are divided into simple and complex. In simple partial seizures, only one neurologic modality is affected during the seizure. The resulting symptoms depend on the area of the brain cortex from which the seizure arises. Motor (focal) seizures may produce clonic hand movements. Sensory, autonomic, and psychiatric symptoms may be expressed as visual phenomena, olfactory sensations (usually unpleasant), déjà vu phenomena, and formed hallucinations or memories. These “auras” are merely simple partial seizures.
Complex partial seizures (psychomotor or temporal lobe seizures) are associated with alteration, but not loss, of consciousness. The patient is awake and staring blankly but is not responsive to external stimuli. These seizures may be accompanied by automatism (repetitive, purposeless movements, such as lip smacking and chewing, hand wringing, patting, and rubbing) and last 30 to 50 seconds. They are followed by postictal confusion and occur weekly to monthly.
Generalized tonic-clonic seizures are frightening and inspire observers to “do something,” but usually it is necessary only to stand by and prevent the patient from injury.
The age of the patient is associated with the probable underlying cause of a first seizure and therefore is a factor in disposition. In the 12- to 20-year-old patient, the seizure is probably “idiopathic,” although other causes are certainly possible. In the 40-year-old patient experiencing a first seizure, neoplasm, posttraumatic epilepsy, and withdrawal must be excluded. In the 65-year-old patient experiencing a first seizure, cerebrovascular insufficiency must also be considered. With elderly patients, the possibility of an impending stroke, in addition to the other possible causes, should be kept in mind during treatment and workup.
Also, patients should be discharged for outpatient care only if there is full recovery of neurologic function, should possibly be given a full loading dose of phenytoin, and should make clear arrangements for follow-up or return to the ED if another seizure occurs. An EEG can usually be done electively, except in cases of status epilepticus. A toxic screen may be needed to detect the many drug overdoses that can present as seizures, including overdoses of drugs such as amphetamines, cocaine, isoniazid, lidocaine, lithium, phencyclidine, phenytoin, and tricyclic antidepressants.
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