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Biomedical subjects

Christoph Helmstaedter

Publications and source records attributed to Christoph Helmstaedter.

28 records · Page 2Linked to original sources
PubMed2003

Outcome in psychogenic nonepileptic seizures: 1 to 10-year follow-up in 164 patients.

Our knowledge of longer term outcome in psychogenic nonepileptic seizures (PNESs) patients is limited; we know less still about factors predicting prognosis. This study was intended to describe outcome in a large cohort and to identify predictive clinical and psychological factors to generate new ideas for treatment. One hundred sixty-four adult patients with PNESs (66.7%) responded to outcome, personality, and psychosymptomatology questionnaires (Dimensional Assessment of Personality Pathology-Basic Questionnaire [DAPP-BQ], Dissociative Experiences Scale, and Screening Test for Somatoform Symptoms) a mean of 11.9 years after manifestation and 4.1 years after diagnosis of PNES. Additional clinical data were retrieved from hospital records. The responses showed that 71.2% of patients continued to have seizures and 56.4% were dependent on social security. Dependence increased with follow-up. Outcome was better in patients with greater educational attainments, younger onset and diagnosis, attacks with less dramatic features, fewer additional somatoform complaints, and lower dissociation scores. Better outcome was associated with lower scores of the higher order personality dimensions "inhibitedness," "emotional dysregulation," and "compulsivity" but not "dissocial behavior" (DAPP-BQ). Outcome in PNESs is poor but variable. Clinical and personality factors can be used to provide an individualized prognosis. By generating a patient-specific profile, they show particular maladaptive traits or tendencies that can identify goals for psychological therapy.

Adult↗
PubMed2003

Significant improvement in frontal lobe associated neuropsychological functions after withdrawal of topiramate in epilepsy patients.

RATIONALE: Topiramate (TPM) is a highly effective anticonvulsant drug, but a comparably high rate of cognitive adverse effects have been reported. In this study, we investigated changes in frontal lobe associated cognitive measures after TPM withdrawal in epilepsy patients hospitalized for presurgical evaluation. METHODS: Twenty epilepsy patients were administered a brief neuropsychological test battery before and after withdrawal of TPM. Neuropsychological evaluation included a verbal fluency task, verbal (Wechsler's digits) and spatial spans (Corsi block-tapping) and Trail Making Test (TMT, parts A and B). Median baseline dosage of TPM was 237.5mg/d, the median retest-interval was 8 days. Results were compared to a matched group of patients, who had been tested and retested before and after reduction of AEDs other than TPM at comparable time intervals. RESULTS: After TPM withdrawal, group performance appeared significantly improved in five of six tests administered. The scores of the control patients remained largely unchanged after drug reduction. After withdrawal, the scores of the TPM group did not differ significantly from the results of the control group whereas pronounced differences had been observed before. Individual improvement became apparent in the majority of patients. Cognitive performance was not correlated to current daily dosages/current blood serum levels of TPM. CONCLUSION: Withdrawal of TPM causes significant improvement in frontal lobe associated measures like verbal fluency and working memory. As withdrawal was part of the preoperative work-up, and not initiated because of patients' complaints or hints of intoxication, cognitive impairment due to TPM appears to be easily overlooked and underestimated.

Adult↗
PubMed2003

Are there physical risk factors for psychogenic non-epileptic seizures in patients with epilepsy?

UNLABELLED: Patients with epilepsy may have additional psychogenic non-epileptic seizures (PNES). It has been suggested that PNES are more common if patients with epilepsy are female, develop epilepsy later in life and have right-sided brain lesions. We examine whether these or other physical factors affect the risk of PNES in patients with epilepsy in a controlled study. METHODS: Ninety consecutive patients with PNES and concurrent epilepsy (PNES+E group) and 90 consecutive patients with epilepsy alone (epilepsy group) were compared with regard to the variables sex, age at onset of epilepsy, epilepsy type (focal/generalised), location and lateralisation of epileptogenic zone, aetiology of epilepsy, interictal epileptiform potentials, magnetic resonance imaging (MRI) abnormalities, neuropsychological (NPS) deficits and intelligence quotient (IQ). RESULTS: Female sex (P<0.001), abnormal visual memory (P=0.012), global NPS impairment (P=0.029), and low IQ category (P=0.005) were associated with a higher risk of PNES. Other variables did not differ between the groups. CONCLUSIONS: In patients with epilepsy, female sex, poor visual memory or global neuropsychological underperformance and low IQ are associated with an increased risk of PNES. MRI changes, epileptiform EEG abnormalities and location of epileptogenic zone do not show a predilection for one hemisphere.

Adult↗
PubMed2003

Rhinal-hippocampal EEG coherence is reduced during human sleep.

The deficiency of declarative memory compared with waking state is an often overlooked characteristic of sleep. Here, we investigated whether rhinal-hippocampal coherence, an electrophysiological correlate of declarative memory formation, is significantly altered during sleep as compared with waking state. For this purpose, we analysed recordings of intracranial EEG activity during sleep obtained directly from within the medial temporal lobe in patients with unilateral temporal lobe epilepsy. We found a general reduction of rhinal-hippocampal EEG coherence during sleep compared with waking state, which was most pronounced within the upper gamma bands (average decrease up to 56%). The observed coherence changes clearly differ from findings reported for surface EEG data and thus appear to be specific for the medial temporal lobe. The decrease of rhinal-hippocampal EEG coherence from waking state towards sleep may yield an electrophysiological explanation for the sleep-related deficiency of declarative memory.

Adult↗
PubMed2002

Interaction of cognitive aging and memory deficits related to epilepsy surgery.

Temporal lobe epilepsy surgery can cause significant memory impairment. This study was intended to examine whether surgery also could affect prognosis of memory in older age. Age regression of verbal memory was examined in 187 patients (before and 1 year after left temporal lobe surgery) and 264 healthy controls. Eighty patients underwent selective amygdalohippocampectomy, and 107 patients underwent anterior two-thirds temporal lobectomy. Amygdalohippocampectomy patients had mesiotemporal epilepsy; anterior two-thirds temporal lobectomy patients had more extramesial or diffuse seizure onset zones. Memory was assessed by word list learning for its more mesial (consolidation/retrieval) and more neocortical (learning) aspects. Patients showed significant preoperative memory impairment. Independent of seizure outcome and surgical approach, surgery had significant negative effects on learning and consolidation/retrieval. In the amygdalohippocampectomy group, preoperative and postoperative age regressions of learning and consolidation/retrieval were not different from those of controls. In the anterior two-thirds temporal lobectomy group, age regression of verbal learning became steeper after surgery, and consolidation/retrieval was negatively correlated with older age and later onset of epilepsy even before surgery. The data confirm that age regression of verbal memory in left temporal lobe epilepsy is similar to that in healthy controls. Both left anterior two-thirds temporal lobectomy and amygdalohippocampectomy worsen verbal learning and memory and bring patients closer to cognitive disability. Particularly in anterior two-thirds temporal lobectomy patients, surgery and reduced capacities for compensation cause acceleration of lifetime memory decline. The results support earlier and tailored epilepsy surgery and suggest that memory prognosis in older age should be considered if more extensive temporal resections would be inevitable.

Adolescent↗
PubMed2002

Memory reorganization in adult brain: observations in three patients with temporal lobe epilepsy.

We present three patients with left-sided temporal lobe epilepsy who exhibited preoperatively a neuropsychological pattern characteristic for interhemispheric language transfer (marked nonverbal memory deficits, relatively preserved verbal memory and language performance). The Wada test indicated atypical language dominance in two patients, but one patient was clearly left hemispheric language dominant. All patients showed a marked recovery of nonverbal memory after left-sided surgery. Results are discussed with respect to memory transfer and plasticity for memory functions in the adult brain.

Adult↗
PubMed2002

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.

Adult↗
PubMed2002

Prognostic factors and outcome after different types of resection for temporal lobe epilepsy.

OBJECT: It is unknown whether different resection strategies for temporal lobe epilepsy (TLE) produce alterations in seizure control or neuropsychological performance. METHODS: A series of 321 patients who underwent surgery for TLE between 1989 and 1997 was submitted to a uni- and multifactorial analysis of clinical, electrophysiological, neuroimaging, neuropsychological, and surgical factors to determine independent predictors of outcome. Until 1993, most patients with TLE underwent standard anterior temporal lobectomy (ATL); beginning in 1993, surgical procedures were increasingly restricted to lesions detected on magnetic resonance (MR) imaging and the presumed epileptogenic foci: for example, amygdalohippocampectomy (AH) or lesionectomy/corticectomy began to be used more often. The mean follow-up duration in this study was 38 months. Two hundred twenty-seven patients were classified as seizure free (70.7%), and 36 patients had rare and nondisabling seizures (11.2%); these groups were summarized as having good seizure control (81.9%). Twenty-four patients attained more than 75% improvement (7.5%), and no worthwhile improvement was seen in 34 cases (10.6%); these groups were summarized as having unsatisfactory seizure control (18.1%). On unifactorial analysis the following preoperative factors were associated with good seizure control (p < 0.05): single and concordant lateralizing focus on electroencephalography studies, low seizure frequency, absence of status epilepticus, concordant lateralizing memory deficit, clear abnormality on MR images, suspected ganglioglioma or dysembryoplastic neuroepithelial tumor (DNT), and absence of dysplasia on MR images. Stepwise logistic regression revealed a model containing five factors that were predictive for good seizure control (p < 0.1): 1) clear abnormality on MR images; 2) absence of status epilepticus; 3) MR imaging-confirmed ganglioglioma or DNT; 4) concordant lateralizing memory deficit; and 5) absence of dysplasia on MR images. Seizure outcome was mainly correlated with diagnosis and clinical factors. No significant differences were found regarding different resection types performed for comparable tumors. Neuropsychological testing revealed better postoperative results after limited resections compared with standard ATL, especially with regard to attention level, verbal memory, and calculated total neuropsychological performance. CONCLUSIONS: Different strategies for surgical approaches in TLE result in equally good outcomes. Seizure outcome is mainly dependent on the diagnosis and clinical factors, whereas the neuropsychological results are more beneficial after resections limited to an epileptogenic lesion and focus.

Adolescent↗
PubMed2001

Behavioral Aspects of Frontal Lobe Epilepsy.

There is growing interest in disorders of behavior, personality, and mood associated with focal epilepsies, though the neuropsychological and behavioral or psychiatric aspects of epilepsy have usually been treated separately. The causes of behavioral disorders in patients with focal epilepsies are multifactorial, though the positive effects of seizure control on behavior suggest that state dependency is a major contributing factor. Patients with temporal lobe epilepsy manifest depression, anxiety, neuroticism, and social limitations, as well as impaired memory. By contrast, studies of cognitive function in patients with frontal lobe epilepsy show executive dysfunctions in response selection/initiation and inhibition, as well as cognitive impairment, hyperactivity, conscientiousness, obsession, and addictive behaviors.

Journal Article↗