Neuropsychological characteristics of mild cognitive impairment subgroups

OBJECTIVE: To describe the neuropsychological characteristics of mild cognitive impairment (MCI) subgroups identified in the Cardiovascular Health Study (CHS) cognition study. METHODS: MCI was classified as MCI-amnestic type (MCI-AT): patients with documented memory deficits but otherwise normal cognitive function; and MCI-multiple cognitive deficits type (MCI-MCDT): impairment of at least one cognitive domain (not including memory), or one abnormal test in at least two other domains, but who had not crossed the dementia threshold. The MCI subjects did not have systemic, neurological, or psychiatric disorders likely to affect cognition. RESULTS: MCI-AT (n = 10) had worse verbal and non-verbal memory performance than MCI-MCDT (n = 28) or normal controls (n = 374). By contrast, MCI-MCDT had worse language, psychomotor speed, fine motor control, and visuoconstructional function than MCI-AT or normal controls. MCI-MCDT subjects had memory deficits, though they were less pronounced than in MCI-AT. Of the MCI-MCDT cases, 22 (78.5%) had memory deficits, and 6 (21.5%) did not. MCI-MCDT with memory disorders had more language deficits than MCI-MCDT without memory disorders. By contrast, MCI-MCDT without memory deficits had more fine motor control deficits than MCI-MCDT with memory deficits. CONCLUSIONS: The most frequent form of MCI was the MCI-MCDT with memory deficits. However, the identification of memory impaired MCI groups did not reflect the true prevalence of MCI in a population, as 16% of all MCI cases and 21.5% of the MCI-MCDT cases did not have memory impairment. Study of idiopathic amnestic and non-amnestic forms of MCI is essential for an understanding of the aetiology of MCI.     

Clinical characteristics of psychogenic nonepileptic seizure status in the long-term monitoring unit

Patients with psychogenic nonepileptic seizures (PNES) mimicking status epilepticus (PNES-status) are at risk of iatrogenic complications. Our aim was to assess whether the population of patients with PNES who develop PNES-status are distinguishable. Retrospectively, we identified patients with PNES-status and compared them with patients with PNES without status and with patients with electroclinical status epilepticus (SE). Of 49 patients with PNES, 9 had PNES-status (18.2%) and 40 had PNES only. Compared with patients with PNES, subjects with PNES-status had taken fewer than three antiepileptic medications (P=0.016), had more than one event per week (P=0.026), were more likely to be admitted emergently to the monitoring unit (P=0.007), had shorter long-term monitoring (LTM) stays (P=0.003), and tended to be diagnosed sooner after initial presentation (P=0.058). Use of fewer than three antiepileptic drugs and emergent admission were independent predictors of PNES-status classification on logistic regression. Of 154 patients with epilepsy, 8 had SE during LTM (5.2%), significantly fewer than the proportion with PNES-status relative to PNES (P=0.008); the only clinical variable distinguishing these two groups was a baseline lower seizure frequency among the patients with epileptic seizures (P=0.045). Our results suggest that patients with PNES-status have features that differentiate them from patients with PNES without status and, to a lesser extent, from patients with epileptic seizures.     

Clinical significance of recurrent psychogenic nonepileptic seizure status

Abstract. To explore the clinical significance of a history of recurrent psychogenic nonepileptic seizure status (PNES-status), this study describes the frequency of PNES-status in 85 consecutive PNES patients and examines whether there are relevant differences between patients with a history of recurrent PNES-status and other PNES-patients. PNES patients were also compared with 64 patients with epilepsy. Data were extracted from hospital records and a postal questionnaire (Dimensional Assessment of Personality Pathology-Basic Questionnaire; Screening for Somatoform Symptoms; Dissociative Experience Scale). Of the PNES-patients, 77.6% reported at least one seizure > 30 minutes (PNES-status), 27 % admission to intensive care with status. 38.8% reported recurrent hospital admissions with status (PNES-status group), the remaining patients served as PNES-controls. The only clinical difference between the two PNES groups was that status patients were younger than PNES-controls (mean age 20.3 vs. 30.3 years, p = 0.001). Our results suggest that PNES status is common and often unrecognised. There were no substantial psychometric differences between patients with recurrent PNES-status and other PNES patients although both PNES-groups had more abnormal somatisation, dissociation and personality scores than patients with epilepsy.     

Neuropsychological and computerized axial tomography volume characteristics of empirically derived dementia subgroups

Neuropsychological assessment data from 138 Alzheimer's disease patients were cluster-analyzed to yield five separate subgroups. These clusters are best described as follows. Cluster I is a low-functioning subgroup characterized by severe generalized deficits (N = 25), cluster II is a subgroup characterized by a higher level of visual-spatial skills relative to the other groups (N = 39), cluster III (N = 21) and cluster IV (N = 42) are virtually indistinguishable in terms of verbal ability and memory, but do differ with regard to visual-spatial skills, and cluster V is a subgroup which presented with relatively better preserved verbal abilities (N = 11). Despite their different neuropsychological profiles, the subgroups did not differ significantly with regard to those complaints that were noted early in the course of the disease process. However, they were found to differ significantly with regard to the patients' educational backgrounds, the distribution of males and females, and the age of the patients at the time of onset of the disease. Analysis of the degree and lateralization of cortical atrophy using volumetric techniques suggested little relationship with neuropsychological examination results. Ventricular volume differences among the five subgroups were not found to be statistically significant after the effect of age had been partialled out. Results are discussed in relation to the multiple factors relating to brain structure and cognition in Alzheimer's disease.     

Clinical events in psychogenic non-epileptic seizures based on semiological seizure classification

Abstract

Objectives:

None of the classifications of psychogenic non-epileptic seizures (PNES) have been widely accepted and used by physicians so far. In this study we aimed at classifying PNES on the basis of a modified version of semiological seizure classification (SSC). We also sought to assess the interrater reliability (IRR) of the PNES diagnosis based on SSC.

Methods:

We classified PNES into four types on the basis of our modification of SSC: pseudoaura, dialeptic, motor, and special (atonic, astatic, hypotonic) spells. Pseudoauras were not included in the statistical analysis. Ninety-one PNES attacks were observed during the 55 video-EEG sessions recorded for all patients. The interrater agreement was assessed by the kappa coefficient.

Results:

Twenty-nine women (78·3%) and eight men (21·6%) were surveyed, with a mean age of 28·4 ± 9·6 (range 16–54). The final diagnosis of PNES was established after a mean of 4·5 ± 2·3 years following the onset of PNES attacks in the patients. The mean seizure duration in the PNES was 241 seconds and 40·5% of our patients had PNES longer than 300 seconds. Motor and special PNES were the most common types observed by all the raters. The kappa values for each pair were as follows: Observers I–II 0·51 (p = 0·000), Observers I–III 0·47 (p = 0·000), and Observers II–III 0·73 (p = 0·000).

Conclusions:

Interobserver agreement was moderate and substantial for three observers who classified PNES according to our modified SSC. The modified version of SSC could be used without difficulty in classifying PNES. Using SSC for PNES both shortens the period before diagnosis and eliminates the need to learn another new and acceptable classification for PNES.     

Identifying seizure clusters in patients with psychogenic nonepileptic seizures

The present study explored how seizure clusters may be defined for those with psychogenic nonepileptic seizures (PNES), a topic for which there is a paucity of literature. The sample was drawn from a multisite randomized clinical trial for PNES; seizure data are from participants' seizure diaries. Three possible cluster definitions were examined: 1) common clinical definition, where ≥ 3 seizures in a day is considered a cluster, along with two novel statistical definitions, where ≥ 3 seizures in a day are considered a cluster if the observed number of seizures statistically exceeds what would be expected relative to a patient's: 1) average seizure rate prior to the trial, 2) observed seizure rate for the previous seven days.Prevalence of clusters was 62–68% depending on cluster definition used, and occurrence rate of clusters was 6–19% depending on cluster definition. Based on these data, clusters seem to be common in patients with PNES, and more research is needed to identify if clusters are related to triggers and outcomes.     

Neuropsychological functioning in MRI-derived subgroups of schizophrenia

This study examined neuropsychological functioning in two subgroups of patients with familial schizophrenia. Those who showed evidence of progressive ventricular enlargement observed across serial MRI scans (n=6) were compared with subjects whose ventricular volume remained static (n=10) over an average of 28 months. No differences were found in terms of age, education, ethnicity, level of psychotic symptomatology, DSM-IV subtype, age of onset, or duration of illness. Neurocognitively, the static ventricle group was impaired across more cognitive domains and had a larger percentage of subjects falling into the impaired range on a majority of measures, with the greatest differences on measures of attention (p<0.02) and nonverbal memory (p<0.07). These results suggest that clinically meaningful differences between these two MRI-derived subgroups of patients with schizophrenia may exist, and further underscore the heterogeneity of the illness.     

Cluster analysis of clinical seizure semiology of psychogenic nonepileptic seizures

PURPOSE: To develop an objective classification of psychogenic nonepileptic seizures (NES) based on cluster analysis of clinical seizure semiology. METHODS: We studied the clinical seizure semiology in 27 patients with psychogenic NES documented by prolonged video-EEG monitoring. We analyzed the following clinical symptoms: clonic and hypermotor movements as well as trembling of the upper and/or lower extremities, pelvic thrusting, head movements, tonic posturing backward of the head, and falling. We used cluster analysis to identify symptoms occurring together in a systematic way and thus tried to achieve a clinical classification of psychogenic NES. RESULTS: We could identify three symptom clusters. Cluster 1 was characterized by clonic and hypermotor movements of the extremities, pelvic thrusting, head movements, and tonic posturing of the head, and therefore was named "psychogenic motor seizures." Cluster 2 comprised trembling of the upper and lower extremities and was termed "psychogenic minor motor or trembling seizures." Cluster 3 consisted of falling to the floor as the only symptom and was referred to as "psychogenic atonic seizures." CONCLUSIONS: Our study represents the first study to analyze the clinical semiology of psychogenic NES by cluster analysis, which should be useful for an objective classification of psychogenic NES. This classification should allow both a better characterization of psychogenic NES and an easier differential diagnosis against specific epileptic seizures.     

Predictors of early seizure remission after diagnosis of psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) are very common, but limited outcome data are available. The purpose of this study was to evaluate the predictors of seizure remission after the diagnosis of PNES is made with video/EEG monitoring in an epilepsy referral center. The subjects for this analysis were 48 consecutive patients who returned for follow-up after diagnosis of PNES. We evaluated demographic, psychosocial, educational, and clinical features as predictors of outcome, using logistic regression analysis outcome. At follow-up, only 35% of patients had achieved seizure remission, and only 50% of these were employed. Educational status and being accompanied to the first clinic visit were favorable predictors of outcome. Type of spell was also a predictor: motionless spells had a more favorable outcome. Other variables were not predictors of outcome. These data may help with counseling and resource allocation for patients with PNES.     

Occurrence of a prolonged nonepileptic motor status after a febrile seizure

PURPOSE: Febrile seizures are very common events in the pediatric population, and this disorder could be inherited. A previous article on nonepileptic status after a febrile seizure was published by Japanese authors. They described convulsive manifestations after a febrile seizure with an EEG counterpart characterized by delta activity and rhythmic theta discharges. We report two cases of nonepileptic prolonged motor status occurring after a simple febrile seizure, erroneously diagnosed as an epileptic status. METHODS: An EEG was obtained during the episode in both of the children; for one of them, we performed a video-EEG recording. RESULTS: In both children, this state was characterized by tonic, vibratory posture, and fluctuation of consciousness. The face was not involved, eyes were closed, and the children were not cyanotic. Ictal EEG showed alternating and mixed theta-delta activity. This activity appeared to be rhythmic in some periods. Clinical and EEG features did not change after administration of benzodiazepine. CONCLUSIONS: We believe this uncommon condition to be a nonepileptic phenomenon, occurring after a simple febrile seizure, with favorable prognosis.     

Psychological processes and histories associated with nonepileptic versus epileptic seizure presentations

Nonepileptic seizures (NES) provide a clinical challenge as the mechanisms involved remain uncertain. The present study compares 27 participants with confirmed NES presentations with 39 individuals with epileptic seizure (ES) presentations only, on indices of psychopathology, trauma history, dissociative propensity, and attachment style. Psychopathology and dissociation were found to be significantly elevated in the NES group compared with the ES group. No differences were found between groups in terms of trauma history and attachment style. However, trauma history did correlate significantly with psychopathology in the NES group but not in the ES group. Finally, whereas the relationship between psychological variables and seizure frequency was weak within the ES group, trauma history, a fearful attachment dimension, psychopathology, and dissociation predicted seizure frequency in the NES group. Implications for understanding and interventions with NES presentations are discussed.     

Predicting psychogenic nonepileptic seizures with the Personality Assessment Inventory and seizure variables

Early identification of likely cases of psychogenic nonepileptic seizures may prompt earlier and more appropriate diagnosis and treatment. This study investigated the validity of multiple independent self-report variables in predicting psychogenic nonepileptic versus epileptic seizures. One hundred forty-three patients with psychogenic nonepileptic seizures and 129 patients with epileptic seizures were compared with the Personality Assessment Inventory, age at seizure onset, years since first seizure, and length of seizures. Diagnostic prediction was made by analyses of variance and logistic regressions. Cut scores were developed for the multivariate predictors with maximal sensitivity and specificity. The Personality Assessment Inventory conversion subscale (SOM-C), years since first seizure, and length of seizures provided 84% correct classification. Ninety-six percent of patients meeting cut scores of SOM-C ≥ 70, years since first seizure ≤ 8, and length of seizures ≥ 3 minutes were diagnosed with psychogenic nonepileptic seizures. Results demonstrated good ability to identify likely cases of psychogenic nonepileptic seizurs by multiple predictors that are easily and cost-effectively obtainable.     

Discriminating between epileptic and nonepileptic events: the utility of hypnotic seizure induction

PURPOSE: To determine the validity of the Hypnotic Induction Profile (HIP) followed by seizure induction during continuous video-electroencephalographic (EEG) monitoring to discriminate between epileptic (EE) and nonepileptic events (NEE). METHODS: Eighty-two patients admitted to the Stanford Comprehensive Epilepsy Center for differential diagnosis of seizure-like events were evaluated. Exclusion criteria included inability or refusal to complete the HIP, lack of a "typical" event, an IQ <70, present evidence of psychosis, or a physiological cause for NEE. Sixty-nine patients met these criteria. While undergoing continuous video-EEG monitoring, the patient completed an HIP, an inventory designed to measure the degree of hypnotizability. An attempt was then made to induce the patient's typical events under hypnosis by using a split-screen technique. An event without an EEG correlate was thought to represent an NEE. A diagnosis of NEE was made independently by the neurology team and was compared with results obtained with the hypnotic evaluation. RESULTS: Results for patients with EE were compared with those with NEE and a group consisting of both EE/NEE. All patients with NEE were then contrasted with the EE group. HIP scores for the EE patients indicated lower hypnotizability than the NEE group and were statistically significant when NEE patients and those with NEE/EE were combined. The sensitivity of seizure induction in the diagnosis of NEE was 77%, with a specificity of 95%. CONCLUSIONS: The HIP coupled with seizure induction is a useful technique to aid in the diagnosis of patients with NEE. It is sensitive and specific, and it may provide the patient with a useful behavioral tool to control NEEs. It may also furnish a conduit for long-term treatment.