Psychopathological changes in a patient with rhythmic midtemporal discharges after antiepileptic medication

Abstract

In 1937, Gibbs et al. described rhythmic waves in the frequency range of 4-7 cycle/set during ictal “automatisms.” This pattern, also found in patients with psychomotor seizures (Gibbs et al. 1938), was called “psychomotor variant pattern” by the same authors in 1952. No agreement concerning the clinical significance of these electroencephalographic (EEG) findings was reached in the following years (e.g., Garvin 1953; Gastaut 1953; Gibbs et al. 1963; Gibbs and Gibbs 1964; Small et al. 1968). Garvin (1968) found this “psychomotor variant pattern” in 0.28% of 13,442 patients who had been referred to his EEG laboratory. Eleven of these 38 patients had psychiatric diagnoses like panic episodes, difficulties with school, behavior problem, nervousness. In another study involving 16,800 consecutive EEG recordings during a 5 l-month period, obtained in different EEG laboratories attached to general hospitals, Lipman and Hughes (1969) called the psychomotor variant pattern “rhythmic midtemporal discharges” (RMTD). This characteristic was found in 0.3% of all recordings. Of these 55 cases, 47% (26) had psychiatric disorders, with a paucity of frank psychoses (without further description). The term RMTD had been introduced because the use of the clinical term (psychomotor variant) for the interpretation of EEG has been previously discouraged (Storm van Leeuwen et al. 1966). In 1973, Hughes and Cayaffa suggested an ictal pattern for 11 patients with first evidence of RMTD. This assumption was further emphasized in a later study (Hughes and Olson 1981) involving 1000 patients who showed “temporal lobe discharges” (including RMTD) , as compared to 2000 psychiatric and normal control persons. The authors found that 33% of the RMTD group showed psychopathology, as compared to only 15%25% in all other groups; however, clinical seizures were most common (82%) in patients with anterior temporal discharges and were less frequent in those with midtemporal discharges (27%). The correlation of RMTD with psychopathology was partially reconfirmed later by