Karl E. Misulis, MD, PhD
CHAPTER CONTENTS
◦Spectrum of Clinical Seizures
◦Differential Diagnosis of Seizures
◦Convulsive Status Epilepticus
◦Nonconvulsive Status Epilepticus
Seizure evaluation and management is a core function of the hospital neurologist. Most patients with seizures can be evaluated on outpatient basis, and admission purely for diagnosis of a single seizure is usually not needed. However, we do admit individuals in whom we fear an underlying cause that deserves rapid attention, if there is a prolonged postictal state, or if a patient fails to return to baseline.
OVERVIEW
Spectrum of Clinical Seizures
Classifications of seizures evolve, but generalized and focal seizures continue to be broad categories of interest at initial presentation. The International League Against Epilepsy (ILAE) classification of epilepsies is presented later in this chapter in the section entitled “Epilepsy.” The clinical description in the list presents the seizure types most commonly seen in the hospital setting:
•Generalized tonic-clonic seizure
◦Generalized motor activity usually with generalized tonic posturing then clonic activity. This is usually followed by limp unresponsiveness and labored respiration at termination. There is no focal motor activity at onset. However, some asymmetry, including forced head turning at onset, could still be consistent with a generalized onset.
•Focal seizure evolving to a bilateral, convulsive seizure
◦Focal seizure leading to bilateral motor activity, usually with tonic then clonic activity (but there could be preceding clonic activity). The transition usually includes tonic or clonic activity and forced head turning contralateral to the side where seizures start. The postictal state is similar to what is seen with a generalized onset tonic-clonic seizure.
•Focal motor seizure without evolution to generalized tonic-clonic activity
◦Focal motor activity, usually clonic but could be tonic or dystonic in appearance. The term is usually used for seizures that do not affect consciousness.
•Focal seizures with impairment of consciousness or awareness (complex partial seizures or discognitive seizures)
◦These may start with an aura or with altered awareness/consciousness. There could be total loss of awareness and responsiveness or only subtle confusion or slowing of responses. There may be motor manifestations such as lip smacking/chewing motions (with temporal involvement), fumbling/picking motions, and dystonic posturing of one or more extremities.
Differential Diagnosis of Seizure
The differential diagnosis of clinical seizures includes epileptic seizures versus nonepileptic psychogenic events versus nonepileptic physiological events. Syncope is the most common physiological event in the differential diagnosis.
◦Seizures can vary considerably in clinical manifestations. If seizure is captured on electroencephalogram (EEG), there will be an associated ictal discharge, but EEG changes may not be seen with a focal motor seizure with preserved awareness. Diagnosis is supported by abnormal interictal EEG, but interictal abnormality is not necessary.
•Nonepileptic psychogenic events (also called nonepileptic psychogenic seizures or pseudoseizures)
◦Atypical clinical features (below).
◦EEG during an episode is normal or only shows movement and muscle artifact. Long-term recording is sometimes needed.
◦Commonly associated with multifocal myoclonus and even with tonic posturing. Myoclonus is usually of short duration, less than 15 seconds.
•Movement disorder (tremor, myoclonus, asterixis, hemiballismus)
◦Movement disorders with positive motor manifestations can be mistaken for seizure if episodic or episodically worse (e.g., myoclonus from metabolic derangement, paroxysmal dyskinesia). Negative myoclonus can also be seen with toxic-metabolic encephalopathy, most commonly hepatic. Acute onset of a hemiballismus from infarction can also be mistaken for seizure.
Differentiation of epileptic seizure from psychogenic nonepileptic event is crucial and often difficult (see Table 19.1).
Table 19.1 Differentiation of epileptic seizure from psychogenic nonepileptic event
Hospital neurologists are often asked to differentiate seizure from syncope (see Table 19.2).
Table 19.2 Differentiation of seizure from syncope
| Feature | Seizure | Syncope |
| Motor activity | Longer duration, more that 15 seconds. | Brief multifocal myoclonus, lasting less than 15 seconds. |
| Position | No positional provocation. | Upright posture or sitting, if there is an orthostatic component. |
| Appearance | Normal color, flushed, or cyanotic with long-duration. | Pale at onset. |
| Post-episode appearance | Often lethargic and confused for minutes | Post-episode disorientation is brief, if present at all. |
| Vital signs | Often tachycardic and hypertensive during and shortly after the episode. | Hypotensive during the episode but normotensive or even hypertensive after. |
| Prolactin level | Often briefly elevated after a generalized tonic-clonic seizure and to a lesser extent after a focal seizure involving the temporal lobe. | Often elevated after syncope; this is not a differentiating feature. |
Vital signs are particularly problematic, since the report is frequently given that BP was normal or elevated after syncope is over. Determining timing and patient status at the time of the vital signs is key.
Prolactin levels are not as helpful as we would like, partly because of the brief time of elevation and the multitude of other reasons for prolactin elevation. Prolactin does not help in the distinction of seizure and syncope because it can be increased after both. Prolactin is usually not increased with psychogenic nonepileptic seizures unless elevated for another reason. Meds that can give elevated prolactin levels include select antipsychotics, antidepressants, antihypertensive meds (e.g., verapamil), opiates, and H2 antagonists.1
The summary statement of the Therapeutics and Technology Assessment Subcommittee reports that elevated prolactin measured 10–20 minutes after a seizure can be an adjunct in differentiating generalized tonic-clonic and complex partial seizure from psychogenic nonepileptic seizure.2
Symptomatic Seizure
The epilepsies will be discussed in detail in the section entitled “Epilepsy.” Here, we are considering seizures, which are symptomatic of another medical condition in hospitalized patients. Features of some important symptomatic seizures are shown in Table 19.3.
Table 19.3 Symptomatic seizures
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