Postictal switch in blood flow distribution and temporal lobe seizures.

The ictal increase of regional cerebral blood flow has yet to be fully utilised in the investigation of focal seizures. Although single photon emission tomography (SPECT) is being increasingly used in the localisation of epileptic foci, the evolution and time courses of the peri-ictal perfusion changes have yet to be clarified. We performed serial SPECT studies in the interictal, ictal and immediate postictal states in 12 patients with refractory temporal lobe epilepsy to define the patterns and duration of peri-ictal cerebral blood flow changes. Visual analysis showed a constant pattern of unilateral global increases in temporal lobe perfusion during seizures which suddenly switched to a pattern of relative mesial temporal (hippocampal) hyperperfusion and lateral temporal hypoperfusion in the immediate postictal period. Quantitative analysis confirmed the visual assessment. Lateral temporal cortex ictal/normal side to side ratios were increased by mean 35.1% (95% confidence interval 21.8% to 48.4%) more in the ictal studies than in the interictal studies and mesial temporal cortex ratios increased by mean 30.8% (22.4% to 39.2%). In the postictal state, however, lateral temporal ratios were reduced by mean 7.7% (-15.8% to 0.4%) compared with interictal values, whereas mesial temporal perfusion was maintained compared with the interictal studies. These observations provide critical information for interpreting scans which can be used in the localisation of epileptic foci. This postictal switch in blood flow patterns may reflect the underlying metabolic processes of neuronal activation and recovery and have implications for understanding the neurobiology of human epileptic seizures.     

Interictal and postictal circadian and ultradian luteinizing hormone secretion in men with temporal lobe epilepsy

PURPOSE: Hypothalamic regulation of the reproductive axis in temporal lobe epilepsy (TLE), represented by the ultradian pulsatile secretion of luteinizing hormone (LH), has been shown to be altered interictally and postictally. Our objective is to determine if epilepsy or seizures disrupt normal circadian fluctuations of LH as well as circadian organization of ultradian bursts of LH. METHODS: We characterized LH secretion in 10 men with TLE during two 24-h blocks: an interictal epoch and a postictal epoch initiated by a seizure. Serum LH was measured every 10 min and characterized by circadian and ultradian patterns with cosinor and deconvolution analysis. RESULTS: Mean peak serum concentrations of LH occurred at approximately 0400 in controls, were significantly delayed approximately 5 h interictally, and were randomly distributed postictally. Burst amplitudes differed significantly by phase among controls, with the largest amplitudes between 0101 and 0700 and the smallest between 1301 and 1900. No phase differences were present in interictal or postictal epochs. Burst frequency weakly but significantly was slowest between 0101 and 0700 in controls, but did not differ significantly by phase in either interictal or postictal epochs. Postictal LH burst frequencies, but not amplitudes, were significantly decreased immediately postictally. CONCLUSION: The pulsatile secretion of LH in TLE is abnormal both in the circadian as well as the ultradian domain. Interictal effects consist mainly in loss of circadian fluctuations in LH burst amplitude, whereas postictal effects consist of altered burst timing. Altered daily patterns of neuroendocrine signals may underlie other disorders of homeostasis in TLE.     

Prolonged preictal psychosis in refractory seizures: a report of three cases

Seizures and psychosis coexist in a large number of patients with epilepsy, and a significant amount of research on their relationship has been published. There are several reports and reviews on postictal and interictal psychosis in patients with epilepsy. We describe three patients with refractory temporal lobe epilepsy, each of whom presented with a history of episodic psychosis that preceded almost all habitual seizures and, thus, served as a useful warning symptom. All three patients had intractable left complex partial seizures; two had right mesial temporal sclerosis, and the third had a gliotic area in the right frontotemporal region on MRI. This is the first report of psychosis preceding seizures. The literature on seizure anticipation, as well as on the complex relationship between seizures and psychosis, is also reviewed.     

Complete remission of epileptic psychosis after temporal lobectomy: case report

We report a case of a female patient with refractory complex partial seizures since 15 years of age, recurrent postictal psychotic episodes since 35 which evolved to a chronic refractory interictal psychosis and MRI with right mesial temporal sclerosis (MTS). After a comprehensive investigation (video-EEG intensive monitoring, interictal and ictal SPECT, and a neuropsychological evaluation including WADA test) she was submitted to a right temporal lobectomy. Since then, she has been seizure-free with remission of psychosis, although with some persistence of personality traits (hiperreligiosity, viscosity) which had been present before surgery. This case supports the idea that temporal lobectomy can be a safe and effective therapeutic measure for patients with MTS, refractory epilepsy and recurrent postictal epileptic psychosis or interictal epileptic psychosis with postictal exacerbation.     

Lack of aura experience correlates with bitemporal dysfunction in mesial temporal lobe epilepsy

The diagnostic value of lack of aura experience in patients with temporal lobe epilepsy (TLE) is unclear. PURPOSE: To evaluate possible factors of bitemporal dysfunction in patients with mesial TLE who did not experience an aura in electroencephalography EEG/video monitoring for epilepsy surgery. METHODS: Ictal scalp EEG propagation patterns of 347 seizures of 58 patients with mesial temporal lobe sclerosis or non-lesional mesial TLE, interictal epileptiform discharges (IED), presence of unilateral mesial temporal lobe sclerosis in visual magnetic resonance imaging (MRI) analysis, prose memory performance, history or not of an aura, and postictal memory or absence of an aura were analyzed. The ictal EEG was categorized as follows. EEG seizure: (a) remaining regionalized, (b) non-lateralized, (c) showing later switch of lateralization or bitemporal asynchronous ictal patterns. RESULTS: Absent aura in monitoring was significantly correlated with absence of unitemporal MRI sclerosis (P=0.004), bitemporal IED (P=0.008), and propagation of the ictal EEG to the contralateral temporal lobe (P=0.001). Other historical data and interictal prose memory performance were not significantly correlated with absent aura. Ten of 11 patients without aura in monitoring also had absent or rare auras in their history. CONCLUSIONS: Lack of aura experience strongly correlates with indicators of bitemporal dysfunction such as bitemporal interictal sharp waves and bitemporal ictal propagation in scalp EEG, and absence of lateralized MRI sclerosis in patients with mesial TLE. The fact that absent auras are not correlated with episodic memory suggests a transient memory deficit, probably because of rapid propagation to the contralateral mesial temporal lobe.     

Interactions Between Hormones and Epilepsy in Female Patients

Summary: Epilepsy and epileptic seizures may influence the release of hormones from the hypothalamus and the pituitary. After complex-partial seizures or generalized tonic–clonic seizures, serum prolactin increases in about two thirds of cases. Apart from this transient effect, interictal epileptic discharges from the temporal lobe may exert a prolonged influence on hormone release. Changes in luteinizing hormone (LH) pulse frequency and increased prolactin levels have been reported. As a consequence, menstrual cycles may be disturbed. The cyclic change of sex serum hormones during the ovulatory menstrual cycle may have an impact on seizure occurrence during the days of ovulation and/or menstruation (e.g., catamenial seizures). By a supplementation of progesterone during the second half of anovulatory cycles, a decrease of seizure frequency can be achieved.     

SPECT in the localisation of extratemporal and temporal seizure foci.

The yield of ictal, postictal, and interictal SPECT was compared in the localisation of seizure foci in 177 patients with partial epilepsy. In 119 patients with known unilateral temporal lobe epilepsy ictal SPECT (97% correct localisation) was superior to postictal SPECT (71% correct), which was better than interictal studies (48% correct). Similarly, in cases of known or suspected extratemporal epilepsy the yield of ictal SPECT studies was high (92%). By contrast, the yield of postictal studies was much lower (46%) and usually only very early postictal studies were diagnostic. Interictal SPECT was of little value. The accuracy of ictal SPECT in localising temporal lobe seizures is now well established. Extratemporal seizures are often brief and difficult to localise. This report shows that ictal SPECT also has a high diagnostic yield in a wide range of extratemporal epilepsies. The brevity of many extratemporal seizures means that true ictal SPECT examinations can be difficult to achieve, but the high diagnostic yield justifies the special organisational effort needed to obtain such studies.     

The expression of interictal, preictal, and postictal facial-wiping behavior in temporal lobe epilepsy: a neuro-ethological analysis and interpretation

By videotape recordings analysis we investigated the frequencies of interictal, preictal, and postictal wiping or rubbing movements targeting the face region (face wiping, FW) in 17 right and 13 left mesial temporal lobe epilepsy (MTLE) patients. Patients' data were compared with FW frequencies obtained in 22 healthy controls listening to a presentation. Results showed that: (1) FW movements were present in both controls and patients; however, the patient groups showed lower interictal and preictal FW rates relative than controls; (2) right and left temporal lobe seizures were followed by a marked increase in the expression of wiping activities directed to the nose as well as to other face regions with respect to the interictal-preictal period; (3) during the first 5min postictal FW was performed preferentially with the hand ipsilateral to the seizure focus; (4) postictal examination of the patient by an observer, especially if of the opposite sex, resulted in a higher incidence of FW acts. After temporal lobe seizures there is an exaggerated expression of movements targeting the face region, and not exclusively directed to the nose. According to an ethological interpretation of the FW behavior as a motor behavior present throughout the phylogenetic scale, from rodents to primates, we suggest the postictal emergence of an innate action pattern modulated by external emotional-cognitive stimuli.     

Reproductive endocrine disorders in women with partial seizures of temporal lobe origin

Of 50 consecutive women with partial seizures of temporal lobe origin (temporal lobe epilepsy [TLE]) evaluated for reproductive dysfunction, 28 had menstrual problems. Of those, 19 had reproductive endocrine disorders. Polycystic ovarian syndrome and hypogonadotropic hypogonadism occurred significantly more often in women with TLE than in the general female population. Polycystic ovarian syndrome was associated with predominantly left-sided lateralization of interictal epileptic discharges; hypogonadotropic hypogonadism was more commonly found with right-sided discharges. Hyposexuality occurred more often in women with predominantly right-sided interictal epileptic discharges and was associated with low serum luteinizing hormone levels. There are several possible interpretations: epileptic discharges in medial temporal limbic structures may disrupt hypothalamic regulation of pituitary gonadotropin secretion; anovulatory cycles of reproductive endocrine disorders may promote the development of epileptic discharges; and TLE and some associated reproductive endocrine disorders may represent the parallel effects of prenatal factors common to the development of the brain and the reproductive system.     

Medial Temporal Objective Lobe Epilepsy: Videotape Analysis of Clinical Seizure Characteristics

Summary: Purpose: The syndrome of temporal lobe epilepsy has been described in great detail. Here we focus specifically on the clinical manifestations of seizures originating in the hippocampus and surrounding mesial temporal structures.
Methods: Seizure origin was confirmed in 67 cases by depth EEG recording and surgical cure after mesial temporal resection.
Results: Among nonlateralized manifestations, we commonly found oral automatisms, pupillary dilatation, impaired consciousness, and generalized rigidity. Appendicular automatisms were often ipsilateral to the seizure focus, whereas dystonia and postictal hemiparesis were usually contralateral. Head deviation, when it occurred early in the seizure, was an ipsilateral finding, but was contralateral to the seizure focus when it occurred late. Clear Ictal speech and quick recovery were found when seizures originated in the non-language-dominant hemisphere, but postictal aphasia and prolonged recovery time were characteristic of seizure origin in the language-dominant hemisphere.
Conclusions: These signs help to define the mesial temporal lobe epilepsy (MTLE) syndrome and often provide information as to the side of seizure origin.     

Scalp EEG in temporal lobe epilepsy surgery

Electroencephalography (EEG) with standard scalp and additional noninvasive electrodes plays a major role in the selection of patients for temporal lobe epilepsy surgery. Recent studies have provided data supporting the value of interictal and postictal EEG in assessing the site of ictal onset. Scalp ictal rhythms are morphologically complex but at least one pattern (a five cycles/second rhythm maximum at the sphenoidal or anterior temporal electrode) occurs in >50% of patients and has a high predictive value and interobserver reliability for temporal lobe originating seizures. Thorough interictal and ictal scalp EEG evaluation, in conjunction with modern neuroimaging, is sufficient for proceeding to surgery without invasive recordings in some patients. Further studies are required to define the scalp ictal characteristics of mesial vs. lateral temporal lobe epilepsy.     

Revisiting the role of magnetoencephalography in epilepsy

PURPOSE OF REVIEW: This review considers the current role of magnetoencephalography in clinical epileptology. RECENT FINDINGS: While magnetoencephalography and electroencephalography complement each other for interictal spike detection, magnetoencephalography is more sensitive in neocortical epilepsy. In temporal lobe epilepsy, magnetoencephalography can attribute epileptic activity to subcompartments of the temporal lobe and differentiate between patients with mesial, lateral and diffuse seizure onsets. In extratemporal epilepsy, magnetoencephalography provides unique information in nonlesional cases and helps to define the relationship of epileptic activity with respect to lesions and eloquent cortex. Magnetoencephalography also contributes to the clinical decision process in patients with cortical dysplasias, Landau-Kleffner syndrome and recurrent seizures after prior epilepsy surgery. Magnetoencephalography-guided re-evaluation of magnetic resonance imaging helps to reveal previously unrecognized lesions. In a presurgical setting interictal magnetoencephalography was superior to scalp electroencephalography. Complete resection of the magnetoencephalography-defined irritative zone has prognostic implications on postoperative seizure control. Magnetoencephalography can reliably localize sensorimotor and language cortex. Disadvantages of this technique include the difficulties in obtaining ictal recordings and the considerable costs involved. SUMMARY: Magnetoencephalography has been developed to a valuable noninvasive tool in clinical epileptology. The development of approaches which take into account both magnetoencephalography and electroencephalography simultaneously should provide more useful information in the future.     

Role of immediate postictal diffusion-weighted MRI in localizing epileptogenic foci of mesial temporal lobe epilepsy and non-lesional neocortical epilepsy.

OBJECTIVE: To determine whether meaningful changes in signal intensity or in the apparent diffusion coefficient of water (ADC) in the ictal onset zone can be detected through immediate postictal and interictal diffusion-weighted magnetic resonance imaging (DWMRI) in patients with localization-related epilepsy. METHOD: In randomly selected 10 medial and lateral temporal lobe epilepsy (TLE) and four extratemporal epilepsy patients, DWMRI was performed immediately after a seizure and during the interictal period. All 14 patients were non-lesional except for hippocampal sclerosis detected on MRI. The mean time interval from seizure onset to postictal DWMRI was 81 min. Regions of interest (ROI) were selected in both the cortex, which was believed to be the ictal onset zone, and the corresponding anatomical region of the contralateral hemisphere in the postictal and interictal DWMRI. The mean ADC measured from all ROIs was compared. Ictal onset zones were determined by ictal electroencephalography (EEG) and seizure semiology. RESULTS: On visual inspection of postictal and interictal DWMRI, signal changes in the ictal onset zone could be identified in only one patient with medial TLE. The mean ADC values from the ictal onset zones were not significantly different from those of the corresponding contralateral regions of the cortices in both postictal and interictal DWMRI. However, the postictal ADC values of the epileptogenic foci of neocortical epilepsy or neocortical temporal portion of TLE without hippocampal sclerosis were decreased compared with interictal ones in whom both interictal and postictal DWMRIs were obtained (P = 0.028). CONCLUSION: Our results demonstrate that water diffusion can change even after a single seizure in non-lesional neocortical epilepsy.     

Perfusion patterns in postictal 99mTc-HMPAO SPECT after coregistration with MRI in patients with mesial temporal lobe epilepsy

OBJECTIVES—To assess patterns of postictalcerebral blood flow in the mesial temporal lobe by coregistration ofpostictal ^99mTc-HMPAO SPECT with MRI in patients withconfirmed mesial temporal lobe epilepsy.
METHODS—Ten postictal and interictal^99mTc-HMPAO SPECT scans were coregistered with MRI in 10 patients with confirmed mesial temporal lobe epilepsy. Volumetrictracings of the hippocampus and amygdala from the MRI were superimposedon the postictal and interictal SPECT. Asymmetries in hippocampal andamygdala SPECT signal were then calculated using the equation:
% Asymmetry =100 × (right − left) / (right + left)/2.
RESULTS—In the postictal studies, quantitativemeasurements of amygdala SPECT intensities were greatest on the side ofseizure onset in all cases, with an average % asymmetry of 11.1, range5.2-21.9.Hippocampal intensities were greatest on the side of seizureonset in six studies, with an average % asymmetry of 9.6, range4.7-12.0.In four scans the hippocampal intensities were less on theside of seizure onset, with an average % asymmetry of 10.2, range5.7-15.5.There was no localising quantitative pattern in interictal studies.
CONCLUSIONS—Postictal SPECT shows distinctiveperfusion patterns when coregistered with MRI, which assist inlateralisation of temporal lobe seizures. Hyperperfusion in the regionof the amygdala is more consistently lateralising than hyperperfusionin the region of the hippocampus in postictal studies.

     

Postictal Courses of Cognitive Deficits in Focal Epilepsies

Summary: Patients with epileptic seizures frequently complain of long-lasting cognitive impairment after a seizure. We evaluated this issue in 31 patients with epileptic seizures of a frontal (n = 8) or temporal lobe origin [right temporal lobe (RTL) n = 8/left temporal lobe (LTL) n = 151. Seizures were secondarily generalized in 18 patients. Computerized testing of verbal and nonverbal recognition memory was performed before the seizure, directly after postictal reorientation, and 30 min and 1 h later. Repeated testing of 14 healthy persons served as control. The following results were obtained: Depending on seizure generalization, postictal reorientation times were 1–45 min. Frontal lobe seizures showed no effect on postictal memory performances, but verbal and visual recognition memory was significantly decreased after temporal lobe seizures. Decrease in either verbal or visual memory and time of recovery were related to lateralization of seizure onset. Functional recovery after reorientation lasted 30 min to 1 h. The decrease in performance was more severe after generalized seizures. Decision times during memory performance were not significantly affected by the seizures. Temporal lobe seizures lead to circumscribed and long-lasting memory deficits, which can be assumed to affect patients'capabilities seriously. Preand postictal testing is a useful tool for determining postictal cognitive impairment and in determining the site of seizure onset.     

Activation of epileptic foci by transcranial magnetic stimulation: effects on secretion of prolactin and luteinizing hormone

Summary Transient elevation of serum levels of prolactin has been observed following several types of epileptic seizures and after electrical stimulation of limbic temporal lobe structures via implanted electrodes. Transcranial magnetic stimulation has been found to selectively induce epileptiform afterdischarges in the epileptic focus of candidates for epilepsy surgery who suffered from temporal lobe epilepsy. Lateralized serial transcranial magnetic stimulation was therefore used and serum levels of prolactin or luteinizing hormone were measured to find if it could be used as a non-invasive diagnostic tool. The investigation was performed on six patients and five healthy volunteers. In the patients the induction of epileptiform potentials was continuously monitored via subdural electrodes. A transient surge of prolactin and luteinizing hormone was found in only one patient, in whom a complex partial seizure was induced. Thus, transcranial magnetic stimulation appeared not to be helpful for the lateralization of the (primary) epileptic focus during presurgical evaluation.     

Psychosis in epilepsy patients

Summary   Epileptic psychoses reflect a fundamental disruption in the fidelity of mind and occur during seizure freedom or during or after seizures. The psychotic symptoms in epilepsy share some qualities with schizophrenic psychosis, such as positive symptoms of paranoid delusions and hallucinations. Psychotic syndromes in epilepsy are most common but not exclusively associated with temporal lobe epilepsy. De Novo psychosis following epilepsy surgery is rare. Forced normalization—psychosis associated with dramatic reduction of epileptiform activity or seizures is described in small series only. Ictal and postictal psychosis can be prevented with seizure control, but postictal and chronic interictal psychoses require multidisciplinary and psychopharmacologic management.     

Interictal and ictal activity recorded with subdural electrodes during preoperative evaluation for surgical treatment of epilepsy

A total of 94 subdural strip electrodes were implanted in 22 patients during preoperative EEG evaluation for surgery of epilepsy. Eighteen patients had temporal lobe seizure onset, three had frontal lobe seizure onset, and one had occipital lobe seizure onset. Most electrodes (total, 83) were localized over the temporal lobe cortex, but in four cases additional strip electrodes (total, 11) covered the frontal, parietal, and occipital lobe cortexes. The electrodes were left in place for up to 28 days. No complications occurred. Interictally, focal spiking was recorded subtemporally, mostly without being seen in electrodes recording from the lateral temporal cortex. In three patients studied with simultaneous subdural and sphenoidal wire electrodes, spiking recorded from subdural electrodes was often not seen in the sphenoidal recording. There were 151 seizures recorded (with or without simultaneous video monitoring). The mean number of seizures per patient was 6.7 (range, 0–21). The seizures were classified as having focal (80 seizures) or local (71 seizures) onset. It is concluded that subdural electrodes are safe and have a sufficient selectivity with regard to localization of interictal spiking and seizure onset in patients with mesial temporal epileptic lesions. In such cases, electrodes have to be placed subtemporally. Other cortical areas may also be explored with these electrodes.     

The localizing and lateralizing value of ictal/postictal coughing in patients with focal epilepsies.

Postictal coughing has so far been reported to indicate a temporal origin of focal epilepsy. A trend towards non-dominant hemisphere lateralization and mesial temporal localization has been suggested. However, postictal coughing has also been reported in a few patients with extratemporal epilepsies. We have retrospectively evaluated the localizing and lateralizing value of ictal/postictal coughing in 197 patients with temporal and extratemporal epilepsy who received presurgical video-EEG long-term recordings from 1999 to 2001. There was no statistical significant difference in percentage of coughing patients in both groups. However, only patients belonging to the temporal group presented with coughing as a regular element of seizure semiology (simple partial and complex partial seizures) whereas in the extratemporal group coughing occurred more sporadically. Within the temporal group a statistically significant tendency to left-sided seizure onset and a statistically not significant preponderance of mesial seizure onset was observed. Additional vegetative signs were observed only in about half of the patients. These results suggest that coughing occurs in both temporal and extratemporal lobe epilepsy and may only be indicative of temporal lobe seizure onset if representing a regular semiologic element. Coughing may be due to two different mechanisms, one dependent and the other independent from additional vegetative symptoms.     

New-onset mesial temporal lobe epilepsy in a 90-year-old: clinical and EEG features

Although there is a peak in the incidence of epilepsy in the elderly compared with the general population, complex partial seizures represent less than 15% of the seizure types reported. We report on a 92-year-old woman with a 2-year history of daily complex partial seizures. Prolonged video/EEG recording showed bilateral anterior mesial temporal interictal spikes, which predominated on the left, and two typical seizures arising from the left temporal area. Cranial MRI scanning showed multiple lacunar infarcts without temporal lobe involvement or mesial temporal atrophy. Our case appears to be oldest patient in the literature with newly diagnosed mesial temporal lobe epilepsy confirmed by video/EEG recording.