A case of temporal lobe epilepsy with improvement of clinical symptoms and single photon emission computed tomography findings after treatment with clonazepam

Authors


Correspondence address: KatsuyoshiMizukamiMD Department of Psychiatry, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennoudai, Ibaraki 305, Japan

Abstract

Abstract A 26-year-old female presented psychomotor seizures, déjà vu and amnestic syndrome after meningitis at the age of 14 years. Repeated electroencephalograms (EEG) demonstrated occasional spikes localized in the right temporal region in addition to a considerable amount of theta waves mainly in the right fronto-temporal region. Single photon emission computed tomography (SPECT) showed a marked hypoperfusion corresponding to the region in which the EEG showed abnormal findings, although magnetic resonance imaging (MRI) demonstrated no abnormal findings associated with the clinical features. Treatment with clonazepam in addition to sodium valproate resulted in a remarkable improvement of clinical symptoms (i.e. psychomotor seizures and déjà vu), as well as of the EEG and SPECT findings. The present study suggests that SPECT is a useful method not only to determine the localization of regions associated with temporal lobe epilepsy but also to evaluate the effect of treatment in temporal lobe epilepsy.

INTRODUCTION

It is well known that single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) are important methods for assessing abnormalities of the brain and provide a basis for diagnosing various neuropsychiatric disorders. 1,2 Recently, a number of papers have reported a clinical advantage of SPECT for patients with epilepsy in detecting the localization of seizure foci. 3–6 However, to date, only a few papers have demonstrated alterations of SPECT findings between before and after improvement of clinical features in patients with epilepsy. 7,8 In the present paper, we described a patient with temporal lobe epilepsy showing a marked improvement of clinical symptoms as well as SPECT findings with clonazepam treatment.

CASE REPORT

The patient is a 26-year-old female who suffered from meningitis with high fever and convulsion at the age of 14 years. Thereafter, she became forgetful and childish in character. One year later, she presented a strange behavior for a few minutes. She was unconsciously swinging her head up and down, or was speaking to herself, and she was unable to recall what she was doing during these episodes. She was diagnosed as having psychomotor seizure. Although she underwent treatment with anticonvulsants (carbamazepine 600 mg/day or sodium valproate 600 mg/day), her seizures occurred twice a week. At the age of 24 years she presented déjà vu experiences and complained, ‘the happenings here are exactly the same as those which I dreamt before.’ and ‘I saw a terrible dream, and this dream must come true.’ She got excited and called for police because she believed she was to be killed. She was admitted to a mental hospital three times because of these episodic delusional states with excitement. Thus, she was referred to the Division of Psychiatry, University of Tsukuba Hospital for scrutiny.

On admission, her consciousness was alert. She had ‘déjà vu’ experiences several times a day, and also had occasional psychomotor seizures. Amnestic syndrome was also remarkable. Short-term memory disturbance was prominent, and disorientation with respect to time and place was also noted. Personality changes, such as childishness, aspontaneity and euphoria were remarkable. Delusional state was not observed. There was no family history of any neuropsychiatric disorders. Physical examination was unremarkable. Total intelligence quotient (IQ) by the Wechsler Adult Intelligence Scale-Revised (WAIS-R) was 57. Repeated electroencephalograms (EEG) showed occasional spike waves localized in the right temporal region and many theta waves mainly in the right fronto-temporal region (data not shown). Magnetic resonance imaging demonstrated no abnormal finding except for cavum septi pellucidi and cavum Verga ( Fig. 1). Single photon emission computed tomography using [123I]-N-iso-propyl-p-iodoamphetamine ([123I]-IMP) revealed a marked hypoperfusion in the right temporal lobe and to a lesser extent in the right frontal lobe ( Fig. 2A).

Figure 1.

Magnetic resonance imaging demonstrated no abnormal finding except for cavum septi pellucidi and cavum Verga.

Figure 2.

Single photon emission computed tomography demonstrated a marked hypoperfusion in the right temporal lobe and to lesser extent in the right frontal lobe before treatment with clonazepam (A). After the improvement of clinical symptoms, the hypoperfusion improved although a mild hypoperfusion still remained in the right fronto-temporal region (B).

Treatment with clonazepam (initially 1.5 mg/day) in addition to sodium valproate (600 mg/day), resulted in her psychomotor seizure disappearing, and the déjà vu experience decreasing in frequency. Two weeks later, the dose of clonazepam was increased to 2.5 mg/ day, and then she was released from déjà vu, and discharged. Her amnestic syndrome and personality changes remained unchanged. Nine months after recovery, her condition continued to be good with the same medications. At that time the EEG demonstrated no epileptic discharge and a marked decrease in frequency of theta waves. The SPECT demonstrated remarkable recovery of the cerebral blood flow in the right frontal and temporal regions, although mild hypoperfusion still remained in these regions ( Fig. 2B).

DISCUSSION

The patient demonstrated psychomotor seizures, déjà vu, amnestic syndrome as well as personality changes such as childishness, aspontaneity, and euphoria after meningitis. The clinical features of the patient were regarded as those mainly associated with temporal lobe dysfunction and, in part, frontal lobe dysfunction. The SPECT and EEG findings are consistent with these clinical features. In contrast, MRI failed to disclose abnormal findings in the fronto-temporal region. To date, the usefulness of MRI and SPECT remains controversial for temporal lobe epilepsy. Some authors report that SPECT is a useful method to detect localization of the seizure foci. 4–6 Dietrich et al. reported that SPECT is more reliable for determining localization of seizure foci than MRI. 5 On the other hand, Jack Jr et al. drew the reverse conclusion when comparing SPECT and MRI. 9 In the present case, SPECT is more useful in demonstrating abnormal brain regions associated with clinical features.

Notably, in the present study, the hypoperfusion improved when epileptic seizures and déjà vu remarkably improved with clonazepam treatment. To our knowledge, however, no paper has reported that clonazepam has an effect on alterations in the cerebral blood flow. Although some studies demonstrated that several anticonvulsants (i.e. phenytoin, phenobarbital, valproate) might reduce the level of cerebral blood flow 10 or brain metabolism, 11 no study has reported that anticonvulsants increase cerebral blood flow. Terada et al. reported that in a patient of complex partial seizure, SPECT revealed a marked overall increase in cerebral blood flow after clinical improvement. 8 In addition, Dressler et al. also reported that anticonvulsive therapy improved seizures and abnormal SPECT findings, and they pointed out that SPECT might provide information to monitor anticonvulsant therapy. 7 Taken together, it is plausible to consider that in the present case clonazepam improved psychomotor seizures and déjà vu, and these improvements resulted in the recovery of epileptogenic zone function, and of cerebral blood flow as shown by SPECT. However, a mild hypoperfusion still remained in the right fronto-temporal region. These findings may explain the residual symptoms, such as amnestic syndrome and personality changes.

In conclusion, the present study suggests that SPECT is a useful method, not only to detect the region associated with temporal lobe epilepsy, but also to evaluate the effect of treatment in temporal lobe epilepsy.

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