FiMec tremor stabilization spoon: design and active stabilization control of two DoF robotic eating devices for hand tremor patients.

This article is about vibration-damping robotic eating devices designed for use by people who have difficulty in eating due to hand tremors due to neuromuscular system disorder. The robotic eating device has two degrees of freedom (DoF). It contains an active controller structure to absorb vibrations in the y- and z-directions. In the handle part of the robotic eating device, there are two DC motors placed on the y- and z-axis, a three-axis IMU inertia sensor, an embedded system board, and a power unit. To absorb the vibration measured from the IMU sensor, the position control of the two motors to which the spoon is connected is provided by PID controllers. The part of the spoon (the pit surface) where the food is placed is tried to be kept constant. To test the vibration-damping performance of the control method, the dynamic model of the spoon along the eating kinematic trajectory was simulated in the SimMechanics environment using vibration data from ten tremor patients. The results show that the stabilization method can absorb the vibration in the hand of the person in the range of 84-99.409% and successfully provide the stabilization of the spoon tip. This damping rate is promising for providing a healthy diet for hand tremor patients.

Abnormalities of cortical thickness in postictal psychosis.

Postictal psychosis (PIP), the occurrence of psychotic episodes following a seizure, is a common and serious comorbidity in patients with epilepsy. Yet, the anatomical correlates remain poorly defined. Here, we used quantitative MRI morphometry to identify structural abnormalities in the cortex of patients with PIP relative to patients with epilepsy without PIP and age- and gender-matched normal healthy controls. Comparison of patients with epilepsy and PIP with patients with epilepsy without PIP revealed increased cortical thickness in the right lateral prefrontal cortex, right anterior cingulate cortex, and right middle temporal gyrus. The PIP group was distinguished from the EC and NC groups by thicker cortex in the right rostral anterior cingulate cortex and thinner cortex in the right angular gyrus and the left middle temporal region. Findings indicate that PIP is associated with thickening of the right anterior cingulate cortex, which may serve as a marker for patients at risk for developing PIP.

In vitro chemosensitivity in ovarian carcinoma: Comparison of three leading assays.

OBJECTIVE: An alternative approach to the current therapy of ovarian carcinoma is the individualization of treatment by determining the sensitivity of tumoral tissue to chemotherapeutic agents before the initiation of chemotherapy. The objectives of the study are to determine the efficacy of in vitro chemosensitivity assays in ovarian carcinoma and to measure the correlation of three leading assays. MATERIAL AND METHODS: Fresh tumoral tissue samples of 26 newly diagnosed primary ovarian cancer patients were studied with 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolyum bromide (MTT) assay, adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA) and differential staining cytotoxicity (DISC) assays. Chemosensitivity of tumors were studied for paclitaxel, carboplatin, docetaxel, topotecan, gemcitabine, and doxorubicin with each of the three assays. Subgroup analysis was performed for stage, grade, and histologic type. RESULTS: The in vitro chemosensitivity results of MTT, ATP, and DISC assays were found to be similar. The subgroups in which in vitro assays would be more useful were encountered for patients with advanced stage and serous histology ovarian carcinoma. CONCLUSIONS: In vitro chemosensitivity can be determined in ovarian carcinoma with ATP, MTT, or DISC assays before the initiation of chemotherapy. These three assays correlate well with each other and are particularly useful for serous and advanced cancers. Large prospective studies comparing standard versus assay-directed therapy with an endpoint of overall survival are required before routine clinical utilization of these assays.

Controlled release of EGF and bFGF from dextran hydrogels in vitro and in vivo.

In the present study, dextran-epichlorohydrin hydrogels were employed as carriers for the controlled release of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). The hydrogels were synthesized from 50% (by weight) monomeric cross-linker, epichlorohydrin, containing dextran mixtures by intermolecular side-chain reaction of dextran-hydroxyl groups with epichlorohydrin-epoxy groups. The hydrogel disks of 3-mm diameter and 1.5-mm thickness have a high swelling capacity (EWC = 650%) and enough mechanical stability for the studies in vivo. Impregnation of EGF and bFGF into the dried hydrogels was carried out by use of phosphate buffered saline solution (PBS, pH = 7.4) containing 0.5 microg mL(-1) EGF and 0.1 microg mL(-1) bFGF, respectively. The in vitro release of growth factors was detected by fluorescence spectroscopy. The prolonged release of EGF is continued up to the 14th day, in comparison with a 26-day release of bFGF. The in vivo studies were realized with subcutaneously implanted hydrogels in Wistar albino rats. The rate of neovascularization was analyzed statistically using one-way analysis of significance with EGF and bFGF incorporated hydrogels. In conclusion, dextran-epichlorohydrin hydrogels were shown to be an alternative delivery system for the release of growth factors.

Correlated conformational fluctuations during enzymatic catalysis: Implications for catalytic rate enhancement.

Correlated enzymatic conformational fluctuations are shown to contribute to the rate of enhancement achieved during catalysis. Cytidine deaminase serves as a model system. Crystallographic temperature factor data for this enzyme complexed with substrate analog, transition-state analog, and product are available, thereby establishing a measure of atomic scale conformational fluctuations along the (approximate) reaction coordinate. First, a neural network-based algorithm is used to visualize the decreased conformational fluctuations at the transition state. Second, a dynamic diffusion equation along the reaction coordinate is solved and shows that the flux velocity through the associated enzymatic conformation space is greatest at the transition state. These results suggest (1) that there are both dynamic and energetic restrictions to conformational fluctuations at the transition state, (2) that enzymatic catalysis occurs on a fluctuating potential energy surface, and (3) a form for the potential energy. The Michaelis-Menten equations are modified to describe catalysis on this fluctuating potential energy profile, leading to enhanced catalytic rates when fluctuations along the reaction coordinate are appropriately correlated. This represents a dynamic tuning of the enzyme for maximally effective transformation of the ES complex into EP.

Quantitative electrophysiological characteristics and subtyping of schizophrenia.

Quantitative descriptors of resting electroencephalogram (EEG) (QEEG) and event-related potentials (QERP) to visual and auditory stimuli were obtained from normal subjects and 94 chronic schizophrenic patients on medication, 25 chronic schizophrenics off medication, and 15 schizophrenics with no history of medication. These schizophrenic groups showed a high incidence of neurometric features that were significantly deviant from normative values. Multivariate discriminant analysis using these features successfully separated the schizophrenic patients from normals with high accuracy in independent replication. The data from the medicated group were subjected to cluster analysis. Newly developed algorithms were used for objective selection of the most effective set of variables for clustering and the optimum number of clusters to be sought. Five clusters were obtained, containing roughly equivalent proportions of the sample with markedly different QEEG profiles. The whole sample was then classified into these clusters. Each cluster contained patients both on and off medication, but patients who had never been medicated were classified into only three of these clusters. No significant clinical or demographic differences were found between members of the five clusters; however, clear differences in QERP profiles were seen. These results are described in detail and possible physiological and pharmacological implications are discussed.

Quantitative electroencephalographic characteristics of crack cocaine dependence.

This study replicates preliminary findings reporting a quantitative electroencephalographic (QEEG) profile of crack cocaine dependence in abstinence. All subjects (n = 52) met criteria for DMS-III-R cocaine dependence (in the form of crack), and were residing in a drug-free therapeutic community. Baseline QEEG evaluations were conducted at intake (5-10 days after last use of crack, and at follow-up (1 month after last reported use). Previous findings of significant excess of relative alpha power and deficit of absolute and relative delta and theta power were replicated in this expanded group. Abnormalities were greater in anterior than posterior regions, and disturbances in interhemispheric relationships were also observed. Further, QEEG showed little change in the interval between the first and second evaluations. This QEEG profile may reflect persistent alterations in neurotransmission as a possible consequence of chronic cocaine exposure.

Quantitative EEG correlates of cognitive deterioration in the elderly.

We report on the quantitative analysis of the EEG (QEEG), using the Neurometric method, in large samples of normal elderly; normal subjectively impaired elderly; patients with mild cognitive impairment; patients presenting with a continuum of primary cognitive deterioration from mild to moderately severe as measured by the Global Deterioration Scale (GDS), compatible with dementia of the Alzheimer's type (DAT). Neurometric QEEG measures were found to be a sensitive index of degree of cognitive impairment, especially reflected in increased absolute and relative power in the theta band, with delta increasing in later stages of deterioration. While these abnormalities were widespread, neither localized or lateralized, MANOVA's for GDS and relative power in theta reached highest significance in a bilateral temporo-parietal arc. A possible relationship between hippocampal dysfunction, cognitive deterioration, and theta abnormalities is discussed in relation to these findings. The results suggest that Neurometric QEEG features are sensitive to the earliest presence of subjective cognitive dysfunction and might be useful in the initial evaluation of patients with suspected dementia, as well as in estimating the degree of cognitive deterioration in DAT patients.

Psychiatric classification of nonconversion nonepileptic seizures.

OBJECTIVE: To determine the frequency and type of non-conversion nonepileptic seizures (NES). BACKGROUND: Although conversion disorder is the most common psychiatric disorder among patients with NES, many patients with nonepileptic paroxysmal behavioral events have other psychiatric disorders, with natural histories and treatments different from those of conversion disorder. DESIGN: Retrospective review of a series of consecutive admissions for video-electroencephalography monitoring. All patients identified with NES were interviewed by a psychiatrist. Patients with conversion and other psychiatric disorders were divided into separate groups. SETTING: A comprehensive epilepsy center. RESULTS: Twenty-one patients evaluated for possible epileptic seizures had a psychiatric disorder other than conversion that accounted for their events. Among these patients, Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) anxiety disorders (n = 9) were the most common diagnosed category, followed by all forms of psychotic disorders (n = 7) and impulse control problems in the setting of attention deficit disorder residual type (n = 2). In contrast to 71 patients with conversion NES seen over the same period of time, the non-conversion group showed no female predominance and the nonconversion patients were significantly less likely than the conversion patients to have been physically or sexually abused in childhood or adolescence. CONCLUSIONS: These results support the validity of the nosologic distinction of nonconversion from conversion NES and suggest that DSM-III-R anxiety disorders are an important diagnostic confound in clinical epilepsy.

Nonepileptic seizures and childhood sexual and physical abuse.

Nonepileptic seizures (NES) must be distinguished from epilepsy to avoid the adverse effects of unnecessary antiepileptic drugs and to initiate appropriate psychiatric treatment. A higher frequency of prior sexual abuse has been suspected in NES, although no prospective controlled study has compared patients with NES and epilepsy. A series of patients with conversion disorder presenting as epilepsy and 140 patients with complex partial epilepsy (CPE) without evidence of conversion were selected from a series of consecutive admissions to a comprehensive epilepsy center. The groups did not differ with respect to age, years of education, race, or marital status, but the percentage of women was greater in the conversion NES group (73.2%) than in the CPE control group (50.7%; p < 0.002). The frequency of a history of sexual or physical abuse was greater in the NES group (32.4%) than in the CPE controls (8.6%; p < 0.000). Severity of sexual but not physical abuse was significantly greater in the NES group relative to controls (p < 0.05). There was a trend for a closer relationship of the perpetrator of sexual abuse to the victim among the NES patients compared with CPE controls (p < 0.1). These results support the impression that childhood abuse is more common among patients with conversion NES than with epilepsy, and suggests that in some cases childhood abuse may be a contributory pathogenetic factor.

Emotional outbursts and post-traumatic stress disorder during intracarotid amobarbital procedure.

Severe emotional outbursts (SEOs) during intracarotid amobarbital procedures (IAP) rarely jeopardize preoperative language and memory testing. Four of four patients (100%) with outbursts had experienced significant emotional trauma (three were raped and one witnessed a decapitation), compared with 26 of 546 patients (4.8%) without outbursts (chi2 = 69.8, p < 0. 0001). Evocative injections were ipsilateral to seizure focus. IAP may disrupt emotional balance in some traumatized patients. Counseling may prevent SEOs.

Clinical profile of patients with epileptic and nonepileptic seizures.

Epileptic seizures (ES) and nonepileptic seizures (NES) often coexist in patients with treatment-refractory seizures. There are few data on ictal features of these different seizure types in the same patient. We identified 20 patients with ES from a group of 99 NES patients (ES/NES) and compared this group with patients with only ES or NES. All 20 ES/NES patients developed NES after ES. Clinical features of NES clearly differed from ES in 18 of 20 cases. In patients with ES/NES their ES were similar to seizures in patients with only ES, and their NES were similar to spells in patients with only NES. ES/NES patients were similar to ES patients in electrodiagnostic and neuroimaging studies, and similar to NES patients in psychiatric interviews and inventories. The clinical manifestations of ES and NES in the same patient are usually different. Both types of events may be stereotypic and can be distinguished and characterized during video-EEG recording. Determining what events are more prevalent or disturbing is critical. Psychiatric and antiepileptic drug treatment may be provided accordingly.

Persistent QEEG abnormality in crack cocaine users at 6 months of drug abstinence.

The major objective of this study was to examine the persistence of abnormal quantitative EEG (qEEG) measures over a six month time interval in subjects in strictly supervised drug free residential treatment for crack cocaine dependence. Seventeen subjects were assessed with qEEG at five to 10 days, one month and six months following their last use of cocaine. No significant changes were noted over time in abnormal qEEG measures, which included deficits of absolute and relative power in the delta band and increased relative alpha power. The persistence of qEEG abnormality in crack cocaine withdrawal suggests a persistent neurobiologic alteration resulting from chronic cocaine exposure. The specificity of the qEEG findings is discussed, and an interpretation is suggested with reference to the hypothesis of neural sensitization in cocaine dependence.

Prediction of treatment outcome in cocaine dependent males using quantitative EEG.

This study investigates the existence of outcome related neurophysiological subtypes within a population of abstinent cocaine dependent adults. We have previously reported and replicated the existence of a distinctive quantitative EEG (QEEG) profile in such a population, and demonstrated the persistence of this pattern at one and six month follow-up evaluations. This profile is characterized by significant deficits of absolute and relative delta and theta power, and excess of relative alpha power, as compared with age expected normal values. Abnormalities were greater in anterior than posterior regions, and disturbances in interhemispheric relationships were also observed. In the current study, 35 adult males with DSM-III-R cocaine dependence, were evaluated while residents of a drug-free residential therapeutic community, 5-15 days after last use of crack cocaine. Using multivariate cluster analysis, two neurophysiological subtypes were identified from the baseline QEEGs; Cluster 1 characterized by significant deficits of delta and theta activity, significant excess of alpha activity and more normal amounts of beta activity (alpha CLUS) and Cluster 2 characterized by deficits of delta, more normal amounts of theta and anterior excess of alpha and beta activity beta CLUS). No significant relationships were found between QEEG subtype membership and length of exposure to cocaine, time since last use of cocaine or any demographic characteristics. Further, no significant relationships were found between the commonly reported comorbid clinical features of depression and anxiety and subtype membership. However, a significant relationship was found between QEEG subtype membership and length of stay in treatment, with members of the alpha CLUS retained in treatment significantly longer than members of the beta CLUS.

Postictal psychosis: a case control series of 20 patients and 150 controls.

We compared clinical data, EEG, and video-EEG studies in a consecutive series of 20 patients with postictal psychosis (PP) to 150 consecutive epilepsy patients with complex partial (CPS) or generalized tonic-clonic (GTCS) seizures but without PP. There was a lucid interval between last seizure and onset of psychosis ranging from 2.3 to 72 h (mean, 25 h). Duration of PP ranged from 16 to 432 h (mean, 83 h). Age, sex, epilepsy type (partial vs. generalized), and history of febrile seizures were similar in the PP and control groups. Patients with PP had more frequent GTCS during monitoring than controls (2.8 vs. 1.3; P < 0.001). Patients with PP were more likely to have a history of encephalitis (P < 0.0001) and psychiatric hospitalization (P < 0.002). More patients with PP had bilateral interictal epileptiform discharges during monitoring than controls (P < 0.0002). Postictal psychosis most often develops in patients with bilateral dysfunction following a cluster of GTCS.

Quantitative EEG correlates of crack cocaine dependence.

Evidence for a distinctive syndrome of neuroadaptation in cocaine dependence has accumulated from behavioral, neurophysiological, and preclinical and clinical pharmacological studies. The authors report on the results of a preliminary investigation of the quantitative electroencephalographic (QEEG) correlates of severe DSM-III-R crack cocaine dependence in seven patients abstinent from cocaine for 1 to 68 days. The major QEEG finding was increased absolute and relative alpha power. Increased alpha power has also been reported in multiple previous studies of depressed patients. This series of crack-dependent patients showed significant depressive morbidity; four patients attempted suicide subsequent to initiating their use of crack and the group mean (+/- SD) Beck Depression Scale score was 18.9 (+/- 6.5). These results complement other studies that support the concept of neuroadaptation to chronic cocaine exposure. Prospective studies correlating QEEG measures with subsequent response to pharmacological interventions for cocaine dependence should be considered.

Nonepileptic seizures.

A review of the literature on epileptic seizures (NES) is presented, a common clinical entity that can be reliably diagnosed if suggestion and video-EEG monitoring are combined with an appreciation of the phenomenology of epileptic and nonepileptic events. Axis I psychiatric disorders with symptoms such as anxiety or dissociation should be considered in the differential diagnosis of NES.

Treatment resistant depression in a case of minor head injury: an electrophysiological hypothesis.

A relatively small but highly concordant literature suggests that manic depressive psychoses may include familial as well as nonfamilial subtypes. The latter, which appears to be an acquired form, follows brain injury of various etiology, displays EEG abnormalities and tends to respond well to anticonvulsant therapy. In this study we postulate an extension of this dichotomy to a larger spectrum of affective disorder, including milder but "treatment resistant" forms often associated with a high degree of dysfunction. Central to this hypothesis is information gathered from the longitudinal study of a well defined case in which precise clinical and electrophysiological data have been obtained at critical junctures. This data also leads us to suggest the existence of a latent vulnerability to psychosocial stressors in a subgroup of minor head injured patients. Once triggered, the resulting psychopathological state may be clinically indistinguishable from similar but etiologically distinct conditions. However, they respond poorly, if at all, to the treatments usually effective for mood disorders, often causing puzzlement and frustration among clinicians as well as mounting hopelessness in patients. This organic mood disorder subtype, which can be described as "neuro-sensitization mood disorder," may be identified by combining a thorough history, including perinatal events and putative brain injury, with electrophysiological data consisting of quantitative EEG (QEEG) in association with evoked potentials. In cases with positive findings, anticonvulsants such as carbamazepine, clonazepam and valproic acid can be a treatment of choice.

Quantitative EEG characteristics of children exposed in utero to cocaine.

Quantitative EEGs (QEEGs) were evaluated in a group of 6 school age children with in utero cocaine exposure. Their QEEGs showed significant deviations from age expected normal values. Further, the QEEG profile of brain dysfunction seen in these children was extremely similar to that previously reported in a large population of crack cocaine dependent adults. These abnormalities were characterized by significant excess of relative power in the alpha frequency band, and deficits of absolute and relative power in the delta and theta bands. Characteristic disturbances in interhemispheric relationships were also present. The similarities between the QEEG profiles of those adults with chronic exposure and children with prenatal exposure suggests that the brain dysfunction reflected in the QEEG is not a result of a transient change in neurotransmission, but a more profound alteration which persists in these children at school age. Further study is required to extend these findings to a larger group of children, and to investigate the potential relationship between these neurophysiological abnormalities and the developmental, behavioral and co-morbid features observed in such children.

QEEG in hemophiliacs with HIV infection.

Conventional visual analysis of the EEG was performed on 320 hemophiliacs infected with HIV, who spanned the range of the Walter Reed (WR) system for classifying clinical stage of HIV infection, and on 50 HIV seronegative hemophiliac controls. Intermittent or paroxysmal slowing was the conventional EEG abnormality most commonly seen in early stages of HIV infection (stages WR1 and 2), with increased focal epileptiform activity and generalized slowing appearing in patients with the full clinical syndrome of AIDS (WR6). Slowing of the manually measured alpha rhythm was noted in stages WR2 and above. Quantitative EEG (qEEG) was obtained in a subset of 103 male HIV seropositive male hemophiliacs and 35 male HIV seronegative hemophiliac controls. The principal findings were a progressive relative increase in theta power with a tendency towards an anterior topographic distribution, and a progressive decline of spectral power in fast alpha relative to slow alpha with increasing severity of HIV disease. Significant qEEG differences from controls were apparent in WR2 subjects (seropositive with lymphadenopathy and without other constitutional symptoms), and were relatively greater in WR3-6 subjects. These results suggest sensitivity of qEEG to early CNS involvement with HIV infection.