Biomedical subjects

Prabha Siddarth

Publications and source records attributed to Prabha Siddarth.

24 records · Page 2Linked to original sources

PubMed2003

MMSE items predict cognitive decline in persons with genetic risk for Alzheimer's disease.

Performance on individual Mini-Mental State Examination (MMSE) items can predict incident Alzheimer's disease (AD). The purpose of the current study is to determine whether, in nondemented persons with and without the apolipoprotein E-4 (APOE-4) genetic risk for AD, a subset of MMSE items predict cognitive decline. Fifty-four nondemented subjects, 23 with at least one copy of the APOE-4 allele and 31 without APOE-4, were given the MMSE and cognitive tests at baseline and 2-year follow-up. MMSE total score and a subset of MMSE items including delayed recall, serial 7s, pentagon, and orientation to time and place were used to predict change on cognitive tests. The subset of MMSE items significantly predicted decline in visuo-spatial construction and naming in APOE-4 carriers but not in noncarriers. Performance on a subset of MMSE items, combined with APOE-4 genotype, may aid in identifying high-risk persons for research or follow-up.

Aged↗

PubMed2002

Developmental outcome with and without successful intervention.

A review of the literature on the developmental outcome of medically and surgically treated symptomatic infantile spasms (IS) indicates that poor seizure control, severe mental retardation, and marked behavioral disorders are found at long-term outcome of symptomatic IS. The 2-year outcome findings of the UCLA Pediatric Epilepsy Surgery Research Group in children with symptomatic infantile spasms and in children with early onset intractable symptomatic epilepsy other than IS (non-IS) demonstrate impaired development of cognition, language, and social communication despite improved seizure control. The social communication deficits of these children are similar to those found in autistic children. Finally, the underlying pathology of the resected brain, rather than ongoing seizures and seizure type, plays an important role in development of the remaining brain tissue and the outcome of early onset symptomatic IS and non-IS.

Child Behavior↗

PubMed2002

Differentiating between reflex and spontaneous blinks using simultaneous recording of the orbicularis oculi electromyogram and the electro-oculogram in startle research.

The present study documents the differences between reflex and spontaneous blinks by recording the vertical electro-oculogram (EOG) along with the orbicularis oculi electromyogram (OO-EMG). EOG and OO-EMG were applied without fixation of the head in 15 freely moving children during an auditory startle experiment. Results revealed that the easily-recorded EOG shows the same relationships between orbicularis oculi contraction and velocity of lid movement in startle blinks as the head-constraining methods, e.g. the magnetic search coil, used in previous studies. The OO-EMG onset occurred before the EOG onset in most reflex blinks while no such pattern occurred for spontaneous blinks. In comparison with spontaneous blinks, reflex blinks showed a shorter duration between onset and peak and between onset and offset in OO-EMG and EOG. In addition, reflex blinks showed greater OO-EMG activity and smaller EOG-recorded lid movements compared with spontaneous blinks. Simultaneous recording of OO-EMG and EOG can distinguish reflex from spontaneous blinks and lid saccades in populations, e.g. children, that cannot tolerate head restraint and in experiments permitting or requiring movement.

Blinking↗

PubMed2002

Social communication in children with epilepsy.

BACKGROUND: This study examined measures of social communication that involve the use of language in formulating and organizing thoughts and its relationship with seizure-related, developmental, cognitive, and behavioral variables in 92 children with complex partial seizure disorder (CPS), 51 with primary generalized epilepsy (PGE), and 117 normal children, aged 5.1-16.9 years. METHODS: Coding the children's speech samples with the Kiddie Formal Thought Disorder Rating Scale (Caplan et al., 1989) and Halliday and Hasan's (1976) analysis of cohesion demonstrated social communication deficits in both seizure disorder groups. RESULTS: The CPS patients had both formal thought disorder and cohesion deficits and the PGE group had mild cohesion deficits. IQ, as well as fronto-temporal and bilateral spike and wave activity were associated with the severity of the social communication deficits of the CPS group. The social communication deficits of the PGE group, however, were related to IQ and seizure control. CONCLUSIONS: Recurrent CPS and PGE and fronto-temporal localization of epileptic activity might impair the development of children's communication skills.

Adolescent↗

PubMedDate not supplied

Apolipoprotein epsilon4 allele status, depressive symptoms, and cognitive decline in middle-aged and elderly persons without dementia.

OBJECTIVE: Because the apolipoprotein epsilon4 (APOE-epsilon4) allele or depressive symptoms may increase the risk for development of Alzheimer disease (AD), the authors assessed APOE-epsilon4 status, baseline level of depressive symptoms, and subsequent cognitive decline in middle-aged and older persons without dementia. METHODS: The 49 subjects (age range: 51-85 years) included 20 with and 29 without APOE-epsilon4. Baseline and follow-up neuropsychological assessments determined the degree of cognitive decline. RESULTS: Baseline mild depressive symptoms were greater in APOE-epsilon4 carriers than in non-carriers. The subject groups demonstrated significant cognitive decline at follow-up. APOE-epsilon4 carriers showed a significantly greater rate of verbal memory decline than non-carriers. Baseline depressive symptoms, however, did not predict future cognitive decline. CONCLUSIONS: These results suggest that APOE-epsilon4 carriers may have a greater severity of depressive symptoms than non-carriers. The APOE-epsilon4 allele (but not baseline mild depressive symptoms) is associated with verbal memory decline in middle-aged and older persons. Because of the limited range of depression scores in our sample, these findings should be interpreted with caution and not be generalized to patients with syndromal depression.

Aged↗

PubMedDate not supplied

Localization of neurofibrillary tangles and beta-amyloid plaques in the brains of living patients with Alzheimer disease.

The authors used 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ([18F]FDDNP), a hydrophobic radiofluorinated derivative of 2-(1-[6-(dimethylamino)-2-naphthyl]ethylidene)malononitrile (DDNP), in conjunction with positron emission tomography to determine the localization and load of neurofibrillary tangles (NFTs) and beta-amyloid senile plaques (APs) in the brains of living Alzheimer disease (AD) patients. Previous work illustrated the in vitro binding characteristics of [18F]FDDNP to synthetic beta-amyloid(1-40) fibrils and to NFTs and APs in human AD brain specimens. In the present study, greater accumulation and slower clearance was observed in AP- and NFT-dense brain areas and correlated with lower memory performance scores. The relative residence time of the probe in brain regions affected by AD was significantly greater in patients with AD (n=9) than in control subjects (n=7; p=0.0007). This noninvasive technique for monitoring AP and NFT development is expected to facilitate diagnostic assessment of patients with AD and assist in response-monitoring during experimental treatments.

Aged↗