Temporal Lobe Epilepsy Clinical Presentation

Memory impairment

Patients with refractory temporal lobe epilepsy typically have material-specific deficits in memory function as the hippocampi are important structures for memory function. Those patients with dominant temporal lobe epilepsy often have impaired language, function as demonstrated by reduced naming ability on the Boston Naming Test. The hippocampal memory function is tested with the intracarotid amytal test, also termed the Wada test.

Aura

Auras occur in approximately 80% of temporal lobe seizures. They are a common feature of simple partial seizures and usually precede complex partial seizures of temporal lobe origin. Auras may be classified by symptom type, that is, by somatosensory, special sensory, autonomic, or psychic symptoms, described below. If a patient has one seizure focus, the seizure semiology tends to be stereotyped.

Somatosensory and special sensory phenomena

Olfactory and gustatory illusions and hallucinations may occur. Acharya et al found that olfactory auras are more commonly associated with temporal lobe tumors than with other causes of temporal lobe epilepsy.^[3]

Auditory hallucinations consist of a buzzing sound, a voice or voices, or muffling of ambient sounds. This type of aura is more common with neocortical temporal lobe epilepsy than with other types of temporal lobe epilepsy.

Patients may report distortions of shape, size, and distance of objects.

These visual illusions are unlike the visual hallucinations associated with occipital lobe seizure in that no formed elementary visual image is noted, such as the visual image of a face that may be seen with seizures arising from the fusiform or the inferior temporal gyrus.

Things may appear shrunken (micropsia) or larger (macropsia) than usual.

Tilting of structures has been reported. Vertigo has been described with seizures in the posterior superior temporal gyrus.

Psychic phenomena

Patients may have a feeling of déjà vu or jamais vu, a sense of familiarity or unfamiliarity, respectively.

Patients may experience depersonalization (ie, feeling of detachment from oneself) or derealization (ie, surroundings appear unreal).

Fear or anxiety usually is associated with seizures arising from the amygdala. Sometimes, the fear is strong, described as an "impending sense of doom."

Patients may describe a sense of dissociation or autoscopy, in which they report seeing their own body from outside.

Autonomic phenomena

Autonomic phenomena are characterized by changes in heart rate, piloerection, and sweating. Patients may experience an epigastric "rising" sensation or nausea.

Features of temporal lobe complex partial seizure

Following the aura, a temporal lobe complex partial seizure begins with a motionless stare, dilated pupils, and behavioral arrest. Oral alimentary automatisms such as lip smacking, chewing, and swallowing may be noted. Manual automatisms or unilateral dystonic posturing of a limb also may be observed.

Patients may continue their ongoing motor activity or react to their surroundings in a semipurposeful manner (ie, reactive automatisms). They can have repetitive, stereotyped, manual automatisms.

A complex partial seizure may evolve to a secondarily generalized tonic-clonic seizure. Often, the documentation of a seizure notes only the generalized tonic-clonic component of the seizure. A careful history from the patient or an observer is needed to elicit the partial features of either a simple seizure or a complex partial seizure before the secondarily generalized seizure is important.

Patients usually experience a postictal period of confusion, which distinguishes temporal lobe epilepsy from absence seizures, which are not associated with postictal confusion. In addition, absence seizures are not associated with auras or with complex automatisms. Postictal aphasia suggests onset in the language-dominant temporal lobe.

Most auras and automatisms last a very short period—seconds or 1-2 minutes. The postictal phase may last for a longer period (several minutes). By definition, amnesia occurs during a complex partial seizure because of bilateral hemispheric involvement.