Attention and psychomotor speed decline in patients with temporal lobe epilepsy: A longitudinal study

PurposeTo assess the possible cognitive alterations in epilepsy patients compared with controls over 5 years, and to investigate the clinical variables mainly implied in mental impairment.MethodsIn our longitudinal single-center study, 50 patients with temporal lobe epilepsy (TLE) and 50 controls were administered the same battery of comprehensive neuropsychological tests at baseline and after 5 years.ResultsTLE patients showed a significant impairment in attention and psychomotor speed compared with controls after 5 years, while the other cognitive domains did not exhibit any important changes. This worsening was mainly related to the duration of epilepsy, the age at onset, a history of tonic–clonic seizures and a low educational level.ConclusionsWe believe that tapping the attention and psychomotor speed decline in TLE patients should be considered relevant for future research, in order to achieve a deeper understanding of the cognitive dimensions of this field.     

Chronic epilepsy and cognition: a longitudinal study in temporal lobe epilepsy

It remains unclear whether uncontrolled epilepsy causes mental decline. This longitudinal study contrasts change of memory and nonmemory functions in 147 surgically and 102 medically treated patients with temporal lobe epilepsy. All participants were evaluated at baseline (T1) and after 2 to 10 years (T3). Surgical patients underwent additional testing 1 year postoperatively (T2). Data were analyzed on an individual and group level. Sixty-three percent of the surgical and 12% of the medically treated patients were seizure-free at T3. Fifty percent of the medically treated and 60% of the surgical patients showed significant memory decline at T3 with little change in nonmemory functions (difference not significant). Surgery anticipated the decline seen in the medically treated group and exceeded it when surgery was performed on the left, or if seizures continued postoperatively. Seizure-free surgical patients showed recovery of nonmemory functions at T2 (p < 0.001) and of memory functions at T3 (T3, p = 0.03). Multiple regression indicated retest interval, seizure control, and mental reserve capacity as predictors of performance changes. In addition, psychosocial outcome was better when seizures were controlled. In conclusion, chronic temporal lobe epilepsy is associated with progressive memory impairment. Surgery, particularly if unsuccessful, accelerates this decline. However, memory decline may be stopped and even reversed if seizures are fully controlled.     

Alertness network in patients with temporal lobe epilepsy: a fMRI study

Patients with temporal lobe epilepsy (TLE) often suffer from cognitive deficits. However, it remains elusive whether the performance of TLE patients in the attentional networks test (ANT) is impaired. Functional magnetic resonance imaging (fMRI) can accurately reflect the hemodynamics and functional activities in certain regions of the brain. In the current study, we aimed to investigate the characteristics and neural mechanisms of the functions of the alertness network in patients with TLE using the ANT and fMRI. A total of 12 patients with TLE and 8 healthy controls underwent the ANT behavioral tests and subsequent block-design fMRI scanning. The results showed that the response times of the alertness network had no significant difference between the TLE group and the healthy control group. The fMRI data showed that the activation of the cerebellum, right occipital lobe, right frontal and brainstem was significantly weaker in TLE patients than in healthy control. Our data indicate that despite neuropsychological test performance is normal; the alerting network is deficient in the TLE patients. The decreased activation of brain regions of right occipital lobe, cerebellum, right frontal lobe, brain stem and temporal lobe may be the neural basis of altering network impairment in TEL patients.     

Postictal psychosis: a retrospective study in patients with refractory temporal lobe epilepsy

Postictal psychosis (PIP) represents 25% of the psychoses seen in epileptic patients. A high frequency of bilateral independent epileptiform activity has been observed in patients with PIP. The objective of this study was to determine the frequency of PIP in patients with temporal lobe epilepsy (TLE) who underwent video-EEG monitoring and to investigate possible differences between PIP and control patients. METHODS: Clinical, electroencephalographic and neuroimaging data of 5 PIP patients with TLE were compared with data of 50 patients with TLE without psychotic antecedents. Patients with a past history of interictal psychosis were excluded. RESULTS: From 55 patients, 5 were patients with PIP and 50 controls. 31 (62%) were men, 9 (16.4%) had a previous history of encephalitis and 6 (10.9%) of status epilepticus. The mean age was 42.2 years (S.D. 12.93). Mean age at epilepsy onset was 16.95 years (S.D. 12.93) and mean seizure frequency 5seizures/month (S.D. 1.87). The frequency of PIP was 5/55 (9.1%). Previous history of status epilepticus was more frequent in PIP patients than in controls (p: 0.019). PIP patients more frequently had a non-lateralizing ictal EEG than controls (p: 0.001). Bitemporal lobe dysfunction revealed by neuropsychological studies was greater than expected by the observed lesion on MRI studies in patients with PIP. Moreover, the presurgical study was less conclusive in PIP than in control patients (p: 0.049). CONCLUSIONS: PIP is observed in up to 9% of patients with TLE undergoing video-EEG monitoring and most often develops in patients with bitemporal lobe dysfunction.     

Medial temporal lobe atrophy in patients with refractory temporal lobe epilepsy

OBJECTIVE: The objective of this study was to assess the volumes of medial temporal lobe structures using high resolution magnetic resonance images from patients with chronic refractory medial temporal lobe epilepsy (MTLE). METHODS: We studied 30 healthy subjects, and 25 patients with drug refractory MTLE and unilateral hippocampal atrophy (HA). We used T1 magnetic resonance images with 1 mm isotropic voxels, and applied a field non-homogeneity correction and a linear stereotaxic transformation into a standard space. The structures of interest are the entorhinal cortex, perirhinal cortex, parahippocampal cortex, temporopolar cortex, hippocampus, and amygdala. Structures were identified by visual examination of the coronal, sagittal, and axial planes. The threshold of statistical significance was set to p<0.05. RESULTS: Patients with right and left MTLE showed a reduction in volume of the entorhinal (p<0.001) and perirhinal (p<0.01) cortices ipsilateral to the HA, compared with normal controls. Patients with right MTLE exhibited a significant asymmetry of all studied structures; the right hemisphere structures had smaller volume than their left side counterparts. We did not observe linear correlations between the volumes of different structures of the medial temporal lobe in patients with MTLE. CONCLUSION: Patients with refractory MTLE have damage in the temporal lobe that extends beyond the hippocampus, and affects the regions with close anatomical and functional connections to the hippocampus.     

Immunohistochemical study of Metallothionein in patients with temporal lobe epilepsy

Epilepsy is characterized by spontaneous recurrent seizures and temporal lobe epilepsy (TLE) is the most common serious neurological example of acquired and frequent epilepsy. Oxidative stress is recognized as playing a contributing role in several neurological disorders, and most recently have been implicated in acquired epilepsies. The MTs occur in several brain regions and may serve as neuroprotective proteins against reactive oxygen species causing oxidative damage and stress. The main aim of this work was to describe the immunohistochemical localization of MT in the specimens derived from the patients affected by TLE. Histopathological examination showed NeuN, GFAP and MT immunopositive cells that were analyzed for determinate in hippocampal and parietal cortex samples. An increase in the reactive gliosis associated with increased MT expression was observed in patients with TLE.     

Headache among mesial temporal lobe epilepsy patients: a case-control study

Epilepsy and headache are two chronic disorders that are characterized by recurrent attacks, but the relationship between them is not completely understood. Using a structured questionnaire, we investigated the prevalence of headache during the previous year in a homogeneous group of 100 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). The control group consisted of 100 age-matched individuals who were randomized from a nationwide Brazilian headache database. There was a significantly higher prevalence of headache (92%) among the MTLE-HS patients when compared with the controls (73%; p=0.001). Chronic daily headache (CDH) was significantly associated with MTLE-HS (OR 6.1, CI 95% 1.7-22, p=0.005). We did not find any association between the diagnosis of migraine or tension-type headache and MTLE-HS. This study showed that MTLE-HS increases the likelihood of a headache diagnosis. In addition, CDH was more prevalent among the MTLE-HS patients, which supports a common pathophysiological mechanism for epilepsy and headache.     

Seizure-associated hippocampal volume loss: a longitudinal magnetic resonance study of temporal lobe epilepsy

This longitudinal quantitative magnetic resonance imaging study of 24 patients with mild temporal lobe epilepsy shows an ipsilateral hippocampal volume decrease of 9% (range, -30 to +0.5%; p = 0.002, paired t test) over a period of 3.5 +/- 0.7 years. The hippocampal volume loss was correlated to the number of generalized seizures between the scans (p = 0.0007, r = 0.6), suggesting seizure-associated hippocampal damage.     

Hyperfamiliarity in patients with temporal lobe epilepsy

Hyperfamiliarity is a type of paramnesia characterized by an increased feeling of familiarity to unfamiliar faces. This dysfunction has been associated with frontal and temporal lobe pathology. The study investigated hyperfamiliarity in patients with temporal lobe epilepsy (TLE) by assessing their ability to recognize both familiar and unfamiliar faces. We evaluated 61 patients with pharmacoresistant TLE (33 right-sided, 28 left-sided) and 16 controls. The ability to recognize familiar faces was similar in patients and controls, although patients with left-sided TLE showed poorer performance in familiar face naming compared to both right-sided TLE patients and controls. Hyperfamiliarity was observed in a significantly higher number of patients with TLE compared to controls; in subgroup analysis, only right-sided TLE patients expressed hyperfamiliarity. Overall, patients with right-sided TLE showed more severe impairment compared to patients with left-sided TLE. It is proposed that hyperfamiliarity can be a relatively common symptom in patients with treatment-refractory TLE and right-sided focus.     

Cognitive-behavioral therapy for depression in patients with temporal lobe epilepsy: a pilot study

Depression has a high prevalence among patients with temporal lobe epilepsy (TLE). A pilot study was carried out to evaluate group cognitive-behavioral therapy (CBT) as a treatment for depression in patients with TLE. Twenty-three outpatients with TLE and major depressive disorder, according to DSM-IV criteria, were enrolled and divided into two groups to receive 16 weekly sessions of CBT. The primary outcome measures were depression severity (assessed with the Beck Depression Inventory) and quality of life (measured with the Quality of Life in Epilepsy-31). Sixteen patients (70%) completed at least 80% of the sessions. From week 8, CBT had a significant positive effect on severity of depression that lasted until the end of treatment. A significant improvement in quality of life was also observed. CBT seems to be a useful intervention for treating depression and improving quality of life in patients with TLE.     

Auditory temporal processing in patients with temporal lobe epilepsy

ObjectiveAuditory temporal processing is the main feature of speech processing ability. Patients with temporal lobe epilepsy, despite their normal hearing sensitivity, may present speech recognition disorders. The present study was carried out to evaluate the auditory temporal processing in patients with unilateral TLE.Materials and methodsThe present study was carried out on 25 patients with epilepsy: 11 patients with right temporal lobe epilepsy and 14 with left temporal lobe epilepsy with a mean age of 31.1 years and 18 control participants with a mean age of 29.4 years. The two experimental and control groups were evaluated via gap-in-noise and duration pattern sequence tests. One-way ANOVA was run to analyze the data.ResultsThe mean of the threshold of the GIN test in the control group was observed to be better than that in participants with LTLE and RTLE. Also, it was observed that the percentage of correct responses on the DPS test in the control group and in participants with RTLE was better than that in participants with LTLE.ConclusionPatients with TLE have difficulties in temporal processing. Difficulties are more significant in patients with LTLE, likely because the left temporal lobe is specialized for the processing of temporal information.     

Accelerated cognitive decline in a rodent model for temporal lobe epilepsy

ObjectiveCognitive impairment is frequently observed in patients with temporal lobe epilepsy. It is hypothesized that cumulative seizure exposure causes accelerated cognitive decline in patients with epilepsy. We investigated the influence of seizure frequency on cognitive decline in a rodent model for temporal lobe epilepsy.MethodsNeurobehavioral assessment was performed before and after surgery, after the induction of self-sustaining limbic status epilepticus (SSLSE), and in the chronic phase in which rats experienced recurrent seizures. Furthermore, we assessed potential confounders of memory performance.ResultsRats showed a deficit in spatial working memory after the induction of the SSLSE, which endured in the chronic phase. A progressive decline in recognition memory developed in SSLSE rats. Confounding factors were absent. Seizure frequency and also the severity of the status epilepticus were not correlated with the severity of cognitive deficits.SignificanceThe effect of the seizure frequency on cognitive comorbidity in epilepsy has long been debated, possibly because of confounders such as antiepileptic medication and the heterogeneity of epileptic etiologies. In an animal model of temporal lobe epilepsy, we showed that a decrease in spatial working memory does not relate to the seizure frequency. This suggests for other mechanisms are responsible for memory decline and potentially a common pathophysiology of cognitive deterioration and the occurrence and development of epileptic seizures. Identifying this common denominator will allow development of more targeted interventions treating cognitive decline in patients with epilepsy. The treatment of interictal symptoms will increase the quality of life of many patients with epilepsy.     

Interictal SPECT in patients with mesial temporal lobe epilepsy and psychosis: a case-control study

Assessments of the severity of vomiting (weekly frequency), depressive and eating-related psychopathology, anger level and management, and personality dimensions were used to characterize patients with bulimia nervosa binge purging type (BN-BP). The sample comprised 130 outpatients with BN and 130 control women. The Eating Disorder Inventory-2 (EDI-2), the State-Trait Anger Expression Inventory, the Beck Depression Inventory, and the Temperament and Character Inventory (TCI) were administered to all patients. The Self-Directedness dimension of the TCI and the Bulimia subscale of the EDI-2 were the strongest predictors of the severity of bulimic behavior; anger levels and anger expression were not so strongly related to illness severity. A more severe form of bulimic symptomatology probably has substrata in specific character deficits (low Self-Directedness on the TCI) and particular psychopathological features (high bulimia on the EDI-2). Patients with a high frequency of vomiting need specific therapeutic interventions to enhance the character dimension of Self-Directedness.     

Late-onset temporal lobe epilepsy with unilateral mesial temporal sclerosis and cognitive decline: A diagnostic dilemma

We present a patient with new onset temporal lobe epilepsy and cognitive decline in his sixth decade with unilateral hippocampal atrophy on structural brain imaging, compatible with mesial temporal sclerosis. This unusual clinical scenario presented a challenging differential diagnosis since it may overlap with primary cognitive disorders, including early-onset Alzheimer's disease and some forms of frontotemporal dementia, and the recently elucidated syndrome of non-paraneoplastic limbic encephalitis associated with voltage-gated potassium channel antibodies.     

Memory outcome after selective amygdalohippocampectomy: a study in 140 patients with temporal lobe epilepsy

PURPOSE: The technique of selective amygdalohippocampectomy (SAH) was originally developed in epilepsy surgery to spare unaffected brain tissue from surgery, thus minimizing the cognitive consequences of temporal lobe surgery. The results of previous studies, however, are equivocal in this regard. This study evaluated memory after SAH in a large sample of patients with mesial temporal lobe epilepsy. METHODS: The 140 patients received material-specific memory tests before and 3 months after unilateral SAH. RESULTS: Significant declines in all aspects of verbal learning and memory were found particularly for the left resected group. With reliability-of-change indices, a high number of patients showed postoperative verbal memory declines, < or = 51% in left SAH and < or = 32% in right SAH. For left SAH, a higher preoperative verbal memory performance, a lower preoperative nonverbal memory score, an older age at surgery, and a later onset of epilepsy predicted a stronger decline in verbal memory. After right SAH, the risk for a verbal memory decline was slightly increased when patients had surgical complications or a presurgical evaluation with bilateral intrahippocampal depth electrodes. Results concerning nonverbal memory were less clear. CONCLUSIONS: The results clearly indicate, that particularly left SAH can lead to a significant decline in memory functions. Predictors of postoperative verbal memory were similar to those reported for temporal lobectomy. Postoperative deteriorations were broader and stronger in our study than in previous studies. We discuss methodologic differences (sample size, retest interval, extent of resection) and other factors as possible reasons.