Neuropsychological performance and seizure-related risk factors in patients with temporal lobe epilepsy: a retrospective cross-sectional study

The aim of this study was to identify the neuropsychological features in patients with temporal lobe epilepsy (TLE) and their correlation with seizure-related variables. For this purpose, we carried out a retrospective analysis of data from 65 patients with TLE who had undergone a comprehensive neuropsychological assessment. The results suggest that the majority of patients with TLE were impaired in more than one cognitive domain, and among these patients, the mean proportions with defective semantic memory, language, motor/psychomotor speed, verbal episodic memory, and executive function were >50% each. Moreover, age at seizure onset was the strongest predictor of general intellectual impairment, and number of antiepileptic drugs and seizure frequency could significantly predict deficits in verbal memory, language, and psychomotor speed. However, epilepsy duration was a less potent predictor of cognitive deficit than has been reported in cross-sectional studies.

Carotid stenting improves cognitive function in asymptomatic cerebral ischemia

OBJECTIVES

Asymptomatic critical internal carotid artery (ICA) stenosis may lead to cognitive impairment. Carotid stenting (CS) may improve cerebral perfusion, but its impact on neuro-cognitive function has been controversial.

METHODS

We prospectively enrolled 34 asymptomatic patients with unilateral ICA stenosis or occlusion, in whom CS was attempted. Computed tomography cerebral perfusion (CTP), and functional assessments including National Institutes of Health Stoke Scale (NIHSS), Bathel Index (BI), and a battery of neuropsychological tests including Mini-Mental State Examination (MMSE), Alzheimer Disease Assessment Scale-Cognitive Subtest (ADAS-Cog), verbal fluency, and Color Trail Making A and B, were done prior to and 3 months after the procedure.

RESULTS

Successful CS was achieved in 28 of 34 patients (82%). Based on the baseline CTP finding and intervention result, patients were divided into three groups: group I (n=6) as ipsilateral cerebral ischemia with failed CS procedure, group II (n=17) as ipsilateral cerebral ischemia with successful CS procedure, and group III (n=11) as normal baseline CTP with successful CS procedure. The demographics and baseline cognitive performances were similar among the three groups. In group II, there were significant improvement in Alzheimer Disease Assessment Scale (pre 6.8 ± 4.3 vs post 4.9 ± 2.8, p=0.033), Mini-Mental State Examination Score (pre 25.8 ± 3.8 vs post 27.4 ± 3.5, p=0.007), and Color Trail test A (pre 120.4 ± 73.9s vs post 95.8 ± 57.6s, p=0.004) after CS. In groups I and III, however, no significant difference was observed in any of the cognitive tests.

CONCLUSIONS

Successful CS improves neurocognitive function in asymptomatic ICA stenosis or occlusion with objective ipsilateral ischemia.

Cognitive stimulation during hospitalization improves global cognition of older Taiwanese undergoing elective total knee and hip replacement surgery

AIM

  This article is a report on a pilot study conducted to determine the effects of cognitively stimulating activities in older patients undergoing elective hip and/or knee replacement.

BACKGROUND

  Cognitive decline occurs in 16-35·5% of older hospitalized patients. In-hospital interventions, such as cognitively stimulating activities, might combat cognitive decline. However, evidence supporting such interventions is limited.

METHODS

For this randomized pilot trial, 50 older patients (90% women with a mean age of 72·8 years) were recruited in 2008 from a tertiary medical centre in Taiwan. While hospitalized, participants in the intervention group received a daily nurse-led, individual-based, cognitive-stimulation intervention. The comparison group received usual care. Cognitive function was assessed using Mini-Mental State Examination at admission, discharge and 1 month after discharge.

RESULTS

  The incidence of cognitive decline (≥2-point decline in cognitive score) by hospital discharge was significantly lower for the intervention group (12%) than the usual care group (44%). The intervention group also had better cognitive scores following hospitalization. Upon discharge, participants in the intervention group scored 1·28 points higher than at admission, whereas participants in the usual care declined by 0·76 points. Improvement in cognitive status persisted for the intervention group (+1·33 points) vs. usual care (-0·26 points) at 1 month after discharge. Group differences in changes were statistically significant both at discharge and 1 month afterwards.

CONCLUSION

  Our cognitive-stimulation intervention benefited global cognitive function among older patients undergoing elective hip and/or knee replacement. The benefit persisted at 1 month after discharge.

Biofunctionalized magnetic nanoparticles for specifically detecting biomarkers of Alzheimer's disease in vitro

Magnetic nanoparticles biofunctionalized with antibodies against β-amyloid-40 (Aβ-40) and Aβ-42, which are promising biomarkers related to Alzheimer's disease (AD), were synthesized. We characterized the size distribution, saturated magnetizations, and stability of the magnetic nanoparticles conjugated with anti-Aβ antibody. In combination with immunomagnetic reduction technology, it is demonstrated such biofunctionalized magnetic nanoparticles are able to label Aβs specifically. The ultralow-detection limits of assaying Aβs in vitro using the magnetic nanoparticles via immunomagnetic reduction are determined to a concentration of ∼10 ppt (10 pg/mL). Further, immunomagnetic reduction signals of Aβ-40 and Aβ-42 in human plasma from normal samples and AD patients were analyzed, and the results showed a significant difference between these two groups. These results show the feasibility of using magnetic nanoparticles with Aβs as reagents for assaying low-concentration Aβs through immunomagnetic reduction, and also provide a promising new method for early diagnosis of Alzheimer's disease from human blood plasma.

Age-related vulnerabilities along the hippocampal longitudinal axis

Evidence for an anterior-posterior gradient of age-related volume reduction along the hippocampal longitudinal axis has been reported in normal aging, but functional changes have yet to be systematically investigated. The current study applied an advanced brain mapping technique, large deformation diffeomorphic metric mapping (LDDMM), automatically delineating the hippocampus into the anterior and posterior segments based on anatomical landmarks. We studied this anterior-posterior gradient in terms of structural and functional MRI in 66 participants aged from 19 to 79 years. The results showed age-related structural volume reduction in both anterior and posterior hippocampi, with greater tendency for anterior decrease. FMRI task contrasts that robustly activated the anterior (associative/relational processing) and posterior (novelty) hippocampus independently, showed only significant reduction of activation in the anterior hippocampus as age increased. Our results revealed positive correlation between structural atrophy and functional decrease in the anterior hippocampi, regardless of task performance in normal aging. These findings suggest that anatomy and functions related to the anterior hippocampus may be more vulnerable to aging, than previously thought.

Frontotemporal dementia and motor neuron disease: report of 3 cases in Taiwan and literature review

PURPOSE

Case reports and a review of literature of the coexistence of motor neuron disease (MND) and frontotemporal dementia (FTD).

CASE REPORT

All three patients demonstrated generalized lower motor neuron signs and very few upper motor neuron signs. In the level of patterns of cognitive impairments, neuropsychological studies do not distinguish between patients with onset of weakness from bulbar palsy and patients with onset of weakness from limbs. All patients of FTD had their onset of MND or amyotrophic lateral sclerosis symptoms within a two-year interval which is similar to previous reports. FTD combined with MND may shorten the survival to less than three years shorter than cases with FTD only. Respiratory failure occurred one to two years after onset of the behavioral symptoms in all patients.

CONCLUSION

We reported three patients of FTD with MND to remind clinicians that these two disorders may occur together on the same patient and that these two disorders may belong to one broad spectrum neurodegenerative disease.

KEYWORDS

motor neuron disease, amyotrophic lateral sclerosis, frontotemporal dementia, frontotemporal lobar degeneration.

Bio-signal analysis system design with support vector machines based on cloud computing service architecture

Today, many bio-signals such as Electroencephalography (EEG) are recorded in digital format. It is an emerging research area of analyzing these digital bio-signals to extract useful health information in biomedical engineering. In this paper, a bio-signal analyzing cloud computing architecture, called BACCA, is proposed. The system has been designed with the purpose of seamless integration into the National Taiwan University Health Information System. Based on the concept of. NET Service Oriented Architecture, the system integrates heterogeneous platforms, protocols, as well as applications. In this system, we add modern analytic functions such as approximated entropy and adaptive support vector machine (SVM). It is shown that the overall accuracy of EEG bio-signal analysis has increased to nearly 98% for different data sets, including open-source and clinical data sets.

Rhombencephalitis as an initial manifestation of primary Sjögren's syndrome: a case report and review of the literatures

PURPOSE

We present a case report and a comprehensive review of the literature concerning aseptic meningoencephalitis and Sjögren's syndrome (SS).

CASE REPORT

We report a 44-year-old woman of primary SS with initial presentation of aseptic meningoencephalitis and a reversible magnetic resonance image (MRI) lesion in the medulla. The diagnosis of primary SS based on ocular dryness, lacrimal hyposecretion, secretory and excretory dysfunction from sialocintigraphy, and positive anti-SS-A antibodies. Corticosteroid and cyclophosphamide therapies reversed the neurological deficits and the MRI lesion.

CONCLUSION

Primary SS may have variable manifestations in the central nervous system which may precede the classic sicca symptoms. SS should be investigated in cases of aseptic meningoencephalitis even without clinical signs of xerostomia or xerophthalmia. MRI is useful in demonstrating brain lesions and in evaluating treatment efficacy of the SS.

rs5848 variant of progranulin gene is a risk of Alzheimer's disease in the Taiwanese population

Progranulin is the precursor of granulins, and its downregulation may lead to neurodegeneration. The single-nucleotide polymorphism rs5848 increases the risk of Alzheimer's disease (AD). We explored the association between alleles of rs5848 and the risk of AD in the Taiwanese population. The frequency of the homozygous TT genotype (16.4 vs. 10.0%) increased in AD subjects by an odds ratio (OR) of 1.87 (p = 0.03) corrected for APOE ε4, age and gender. Interaction between age and homozygous TT genotype accentuated the risk of AD (OR 4.44, p < 0.001). The homozygous TT genotype of rs5848 may play a role in the genetic risk of AD development, especially in the elderly.

Pathophysiology of neuropathic pain in type 2 diabetes: skin denervation and contact heat-evoked potentials

OBJECTIVE

Neuropathic pain due to small-fiber sensory neuropathy in type 2 diabetes can be diagnosed by skin biopsy with quantification of intra-epidermal nerve fiber (IENF) density. There is, however, a lack of noninvasive physiological assessment. Contact heat-evoked potential (CHEP) is a newly developed approach to record cerebral responses of Aδ fiber-mediated thermonociceptive stimuli. We investigated the diagnostic role of CHEP.

RESEARCH DESIGN AND METHODS

From 2006 to 2009, there were 32 type 2 diabetic patients (20 males and 12 females, aged 51.63 ± 10.93 years) with skin denervation and neuropathic pain. CHEPs were recorded with heat stimulations at the distal leg, where skin biopsy was performed.

RESULTS

CHEP amplitude was reduced in patients compared with age- and sex-matched control subjects (14.8 ± 15.6 vs. 33.7 ± 10.1 μV, P < 0.001). Abnormal CHEP patterns (reduced amplitude or prolonged latency) were noted in 81.3% of these patients. The CHEP amplitude was the most significant parameter correlated with IENF density (P = 0.003) and pain perception to contact heat stimuli (P = 0.019) on multiple linear regression models. An excitability index was derived by calculating the ratio of the CHEP amplitude over the IENF density. This excitability index was higher in diabetic patients than in control subjects (P = 0.023), indicating enhanced brain activities in neuropathic pain. Among different neuropathic pain symptoms, the subgroup with evoked pain had higher CHEP amplitudes than the subgroup without evoked pain (P = 0.011).

CONCLUSIONS

CHEP offers a noninvasive approach to evaluate the degeneration of thermonociceptive nerves in diabetic neuropathy by providing physiological correlates of skin denervation and neuropathic pain.

Pharmacological treatment for Alzheimer's disease: current approaches and future strategies

More than a decade after the first approval of the use of acetylcholine esterase inhibitor on patients with Alzheimer's disease, we still not have a single treatment or combination therapy that can effectively stop or reverse the relentless progression of such neurodegenerative disease. Recently therapeutics targeting amyloid hypothesis have undergone scrutiny by many clinical trials. These include gamma secretase inhibitor for reducing beta amyloid formation, agents for preventing aggregation of amyloid oligomers, and immunotherapy for enhancing clearance of amyloid and plaque. Therapies targeting hyperphosphorylated tau is another promising mechanism to be tackled with. Other agents enforcing mitochondria functions, enhancing serotonin receptors, modulating advanced glycation end products, and neurotrophic factors, as well as other therapies are also emerging. We review current treatments and therapeutic strategies already undergone different stage of clinical trails in this report. We propose that therapeutics of various combination composed of symptomatic treatments and disease modifying therapies will become standard regimens of AD treatment with much better efficacy than current approaches.

Role of the premotor cortex in leg selection and anticipatory postural adjustments associated with a rapid stepping task in patients with stroke

The premotor cortex (PMC) plays an important role in selecting and preparing for movement. This study investigates how stroke-induced PMC lesions affect stepping leg selection and anticipatory postural adjustments (APAs) preparation. Fifteen hemi-paretic patients (eight with PMC lesions (PMC(Lesion)) and seven PMC spared (PMC(Spared))) and eight age- and sex-matched healthy adults participated in the study. The subjects performed rapid forward stepping with the right or left leg under simple and choice reaction time conditions. The percentage of trials in which the subject showed the correct initial vertical ground reaction force pattern before lift-off of the stepping leg indicated the accuracy in selecting the designated stepping leg. The latency of bilateral contractions in the tibialis anterior (TA) and the reaction time (RT) of the stepping leg represented the time needed to prepare for stepping-related APAs and stepping movement, respectively. All three groups demonstrated a similar rate of accuracy of the stepping leg selection under both conditions. However, in both conditions, the PMC(Lesion) group exhibited a longer RT and TA contraction latency of the affected leg than the healthy and PMC(Spared) groups. The PMC(Lesion) group also presented a longer TA contraction latency of the unaffected leg than the healthy group in both conditions. These results suggest that the PMC is involved in APAs associated with leg stepping movement and that a PMC lesion in one hemisphere impairs APAs of both the contralateral and ipsilateral legs during stepping.

Folic Acid potentiates the effect of memantine on spatial learning and neuronal protection in an Alzheimer's disease transgenic model

Folic acid deficiency and hyperhomocysteinemia potentiate amyloid-beta (Abeta) neuron toxicity. Memantine, an NMDA antagonist used in moderate to severe AD, is considered to be neuroprotective. We propose that folic acid might have a synergistic effect for memantine in protecting neurons from Abeta accumulation. We treated 8-month-old Tg2576 transgenic mice with memantine (30 mg/kg/day) with or without folic acid (8 mg/kg/day) for 4 months. Escape latencies in the Morris water maze were significantly shorter in the folic acid-memantine treatment group Tg(+)_M+F compared to both the non-treatment transgenic controls Tg(+) and the memantine-treatment group Tg(+)_M (both p < 0.05). Analysis of Abeta40 and Abeta42 showed lower brain loads in both treatment groups but this did not reach statistical significance. Histopathology analysis showed that Tg(+)_M+F had lower ratios of neuronal damage than Tg(+) (p < 0.001) and Tg(+)_M (p< 0.005). DNA analysis revealed that in the Tg(+)M_+F group, transcription was upregulated in 72 brain genes involved in neurogenesis, neural differentiation, memory, and neurotransmission compared to the Tg(+)_M group. In conclusion, we found that folic acid may potentiate the effect of memantine on spatial learning and neuronal protection. The benefit of combination therapy may be through co-action on the methylation-controlled Abeta production, and modification of brain gene expression.

Assessment of behavioral and psychological symptoms of dementia by family caregivers

This study was designed to test the performance and related factors of a self-administered instrument in assessing behavioral and psychological symptoms of dementia (BPSD) by family caregivers. We recruited 173 patients with dementia and major caregivers from two neurological clinics. Information about clinical diagnosis, the Mini Mental State Examination (MMSE), the Clinical Dementia Rating (CDR), the Dementia Behavior Disturbance Inventory (DBDI), and global caregivers' strain were collected from interview and chart review. We found that DBDI has acceptable construct validity and good internal consistency reliability. BPSD was more frequently found in patients with advanced dementia, poor cognitive function and highly correlated to caregivers' strain. Multivariate analysis revealed that female patients and caregivers, advanced CDR stages, patient-caregiver relationship, types of dementia and MMSE score were related to the increase of frequency and disturbance index of DBDI. We concluded that BPSD could be evaluated by family caregivers using a self-administered instrument. Further study is indicated to clarify how caregiver characteristics affect the report of behavioral symptoms, and its clinical importance.

Impaired gist memory in patients with temporal lobe epilepsy and hippocampal sclerosis

PURPOSE

Temporal lobe epilepsy (TLE) is the most common focal epilepsy and frequently causes memory problems. It is often associated with hippocampal sclerosis (HS) and is useful in exploring memory functions. We aimed to examine the effect of restricted hippocampal lesions on gist memory function in patients with TLE.

METHODS

Forty-five patients with TLE and HS (16 left, 15 right, and 14 bilateral lesions) and 22 control subjects were recruited. Patients with magnetic resonance imaging (MRI) or electroencephalography (EEG) evidence of extratemporal lesions were excluded. All participants performed a gist-based recognition task following the Deese-Roediger-McDermott paradigm and were tested for verbal IQ and memory functions. We conducted hippocampal volumetry on MRI of all the participants.

RESULTS

Patients showed multidomain memory impairments. Gist memory was impaired in patients with bilateral HS and probably in patients with right HS. Hippocampal volumetry supported such findings that total volume of hippocampi and volume of right hippocampus correlated positively with gist memory function.

DISCUSSION

HS has a dose effect and a probable right dominance effect on gist memory; good item memory supports gist memory performance; and a disproportionate deficit was noted in tasks with high relational demand but not in tasks with simple association. We should develop memory skills for patients with TLE by enhancing performance of gist memory related to simple association task.

Diffusion tensor changes in patients with amnesic mild cognitive impairment and various dementias

White matter damage and its contribution to clinical manifestations in patients with dementia have been increasingly recognized. To explore white matter changes in different types of dementia, we examined brain water diffusivity with diffusion tensor imaging (DTI). We measured fractional anisotropy and mean diffusivity of multiple white matter regions in patients with amnesic mild cognitive impairment (MCI, n=10), Alzheimer's disease (AD, n=30), subcortical ischemic vascular dementia (SIVD, n=18), frontotemporal dementia (FTD, n=7), and control subjects (n=20). We performed pairwise comparisons in each region of interest between patients and controls. MCI patients showed diffusion tensor change (DTC) in the left anterior periventricular (PV) area, possibly in the right posterior PV area, and the genu of the corpus callosum. AD patients showed DTC in the corpus callosum, and in frontal and parieto-occipital subcortical and anterior PV areas. In SIVD patients, DTC occurred in the genu of the corpus callosum, and in bilateral frontal subcortical and PV areas. FTD patients differed from controls in showing DTC in the temporal and frontal subcortical areas, the genu of the corpus callosum and PV areas. The degree of DTC correlated with the clinical severity of dementia as assessed by the clinical dementia rating (CDR). Mean diffusivity was diffusely and positively associated with the CDR scores. Fractional anisotropy of the PV areas was negatively associated with the CDR scores, suggesting a critical role of the lateral cholinergic pathways.

A warm footbath before bedtime and sleep in older Taiwanese with sleep disturbance

A single-group crossover design was used to examine the effects of a warm footbath on body temperatures, distal-proximal skin temperature gradient (DPG), and sleep outcomes in 15 Taiwanese elders with self-reported sleep disturbance. Body temperatures and polysomnography were recorded for three consecutive nights. Participants were assigned randomly to receive a 41 degrees C footbath for 40 minutes before sleep onset on night 2 or night 3. Mean DPG before lights off was significantly elevated on the bathing night. There were no significant differences in sleep outcomes between the two nights. However, when the first two non-rapid eye movement (NREM) sleep periods were examined, the amount of wakefulness was decreased in the second NREM period on the bathing night.

[Memory and memory disorders]

Memory is a reconstructive process classified as explicit and implicit memory by level of awareness. Explicit memory is a conscious recollection of either episodic or semantic memory. Episodic memory is from personal experience and is context-specific while semantic memory refers to general knowledge. Implicit memory is from priming, procedure memory or skills. On-line message held by the brain is the working memory. Prospective memory is about something to be done in the future. Over-reliance on gist memory brings in false memory. The stirring of emotion has effect on encoding and consolidation. Explicit memory depends on medial temporal and prefrontal lobes. Priming impinges directly on cerebral cortex. Procedure memory or motor skills are closely related to basal ganglia. Cerebellum plays an important role in classical conditioning and complex motor learning. Age effect on memory is mainly from decreased speed and capacity of the central executive function. Age-associated memory impairment could be normal aging while mild cognitive impairment could be preclinical dementia. Alzheimer's disease starts with episodic memory, frontotemporal dementia defects semantic memory and Lewy's body dementia impairs working memory.

An automatic analysis method for detecting and eliminating ECG artifacts in EEG

An automated method for detecting and eliminating electrocardiograph (ECG) artifacts from electroencephalography (EEG) without an additional synchronous ECG channel is proposed in this paper. Considering the properties of wavelet filters and the relationship between wavelet basis and characteristics of ECG artifacts, the concepts for selecting a suitable wavelet basis and scales used in the process are developed. The analysis via the selected basis is without suffering time shift for decomposition and detection/elimination procedures after wavelet transformation. The detection rates, above 97.5% for MIT/BIH and NTUH recordings, show a pretty good performance in ECG artifact detection and elimination.

Institution type-dependent high prevalence of dementia in long-term care units

BACKGROUND/AIMS

It is estimated that there are 90,000 patients with dementia in the 23 million habitants of Taiwan, with a few institutions specialized in dementia care. To assess the need of institutional care for dementia, we investigated the institution prevalence of dementia.

METHODS

We performed stratified randomized sampling of elder residents from different types of institutions in different regions of Taiwan. A 2-stage survey with screening and clinical confirmation was carried out in 2004.

RESULTS

In total, 1,525 residents aged 65 years and over in 60 institutions participated in the study in which 1,308 elders completed the 2-stage survey. Among these, 631 elders were diagnosed as having dementia. The dementia prevalence was 26.8% in the residential houses, 61.8% in the assisted living facilities and 64.5% in the nursing homes. Vascular dementia was the leading cause of dementia in the institutions. Old age, diabetes mellitus and family history of dementia increased risks for both Alzheimer's disease and vascular dementia.

CONCLUSION

The investigation showed that the prevalence of dementia in the long-term care units of Taiwan was much higher than those from community studies and the high prevalence in the institutions depended on the type of the long-term care unit.