Rarely, recurrent attacks of transient amnesia are the only manifestations of temporal lobe epilepsy, although it is unclear whether the amnesia in such patients represents an ictal or postictal phenomenon. These attacks of pure amnesia have been referred to as transient epileptic amnesia (TEA; Palmini et al; Zeman et al). If the patient functions at a fairly high level during the attack, as may happen, there is a resemblance to transient global amnesia (described in Chap. 20). However, in contrast to transient global amnesia, the relative brevity and frequency of the amnesic spells, their tendency to occur on awakening, the impaired performance on complex cognitive tasks, and the absence of repetitive stereotyped questions help to make the distinction.
Some comments are in order concerning the issues of behavioral and psychiatric disorders in patients who have seizures. Data as to prevalence of these disorders have been derived mainly from studies of selected groups of patients attending specialty clinics that tend to treat the most difficult and complicated cases. In one such study (Victoroff), approximately one-third of epileptic patients had a history of major depressive illness, and an equal number had symptoms of anxiety disorder; psychotic symptoms were found in 10 percent. Similar figures, also from a university-based epilepsy center, have been reported by Blumer et al. It must be emphasized that these remarkably high rates of psychiatric morbidity do not reflect the prevalence in the entire population of patients with epilepsy. Epidemiologic studies provide only limited evidence of an association with psychosis in the overall population of epileptics (see Trimble and the review by Trimble for a critical discussion of this subject). Furthermore, it should be borne in mind that many chronic medical conditions are associated with psychiatric reactions. On the other hand, the unpredictability and stigma of the epileptic disorders may contribute to depression and anxiety.
The postictal state in patients with temporal lobe epilepsy rarely incorporates a protracted paranoid-delusional or amnesic psychosis lasting for days or weeks. The EEG during this period may show no seizure discharge, although this does not exclude repeated seizures in temporal lobe structures that are remote from the recording electrodes. This disorder, virtually indistinguishable from psychosis, may also present in the interictal period.
It had been observed that some patients with temporal lobe seizures may exhibit a number of personal peculiarities. It was stated that they are slow and rigid in their thinking, verbose, circumstantial and tedious in conversation, inclined to mysticism, and preoccupied with rather naive religious and philosophical ideas. Obsessionalism, humorless sobriety, emotionality (mood swings, sadness, and anger), and a tendency to paranoia are other frequently described traits. Diminished sexual interest and potency in men and menstrual problems in women, not readily attributable to antiepileptic drugs, are common among patients with complex partial seizures of temporal lobe origin. Geschwind proposed that a triad of behavioral abnormalities—hyposexuality, hypergraphia, and hyperreligiosity—constitutes a characteristic syndrome but this has been disputed.
Bear and Fedio suggested that certain personality traits were more common with right temporal lesions, and that anger, paranoia, and cosmologic or religious conceptualizing are more characteristic of left temporal lesions. However, Rodin and Schmaltz found no features that would distinguish foci on either side and they found no behavioral changes that would distinguish patients with temporal lobe epilepsy from other groups of epileptics. The problem of personality disturbances in epilepsy has not been clarified and many modern clinicians no longer identify these traits as parts of the epileptic syndrome, having in the past been imputed to these patients by societal and medical biases (see review by Trimble) but even this is open to other interpretation.