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Biomedical subjects

P A Spiers

Publications and source records attributed to P A Spiers.

8 recordsLinked to original sources
PubMed1999

Citicoline for traumatic brain injury: report of two cases, including my own.

Citicoline is an investigational new drug in this country that was provided on a compassionate use basis in two cases of traumatic brain injury after horseback riding accidents. While this report is primarily anecdotal, the behavioral observations in both cases suggested atypical patterns of improvement and perhaps greater recovery than might otherwise have been predicted. The side effect profile of this drug is negligible and previous experimental research has yielded positive findings for treatment after stroke and head trauma, as well as memory loss in aging. Consequently, Citicoline may potentially be very helpful for patients suffering traumatic brain injuries and should, in our opinion, be made available and studied further in this clinical population.

Acute Disease↗
PubMed1998

Aspartame: neuropsychologic and neurophysiologic evaluation of acute and chronic effects.

BACKGROUND: Neurobehavioral symptoms have been reported anecdotally with aspartame. OBJECTIVE: This study sought to determine whether aspartame can disrupt cognitive, neurophysiologic, or behavioral functioning in normal individuals. DESIGN: Forty-eight healthy volunteers completed a randomized, double-blind, placebo-controlled, crossover study. The first month was aspartame free. Subjects then consumed sodas and capsules with placebo, aspartame, or sucrose for 20 d each. Order was randomized and subjects were assigned to either a high- (45 mg x kg body wt(-1) x d(-1)) or low- (15 mg x kg body wt(-1) x d(-1)) dose aspartame group. Neuropsychologic and laboratory testing was done on day 10 of each treatment period to determine possible acute effects and on day 20 for possible chronic effects. RESULTS: Plasma phenylalanine concentrations increased significantly during aspartame treatment. Neuropsychologic results; adverse experiences; amino acid, insulin, and glucose values; and electroencephalograms were compared by sex and by treatment. No significant differences were found for any dependent measure. CONCLUSION: Large daily doses of aspartame had no effect on neuropsychologic, neurophysiologic, or behavioral functioning in healthy young adults.

Adult↗
PubMed1998

Preclinical prediction of Alzheimer's disease using SPECT.

BACKGROUND: Regional cerebral perfusion measured by single photon emission computed tomography (SPECT) was examined as a preclinical predictor of the development of Alzheimer's disease (AD). METHODS: Singular value decomposition was used to produce 20 SPECT factors (known as vectors) (n=152). Vector scores were then computed for four groups (n=136), differing in cognitive status: Group 1--normal controls at both baseline and follow-up; Group 2--subjects with "questionable" AD at both baseline and follow-up; Group 3--subjects with questionable AD at baseline who converted to AD on follow-up (Converters); Group 4--subjects with AD at baseline. All SPECT data in the analyses were gathered at baseline. RESULTS: The four groups could be distinguished on the basis of their baseline SPECT data (p < or = 0.00005; hit rate=83%). Regional decreases in perfusion were most prominent among Converters in the hippocampal-amygdaloid complex, the posterior cingulate, the anterior thalamus, and the anterior cingulate. Inclusion of apolipoprotein E status did not significantly improve the discrimination. CONCLUSIONS: SPECT data gathered and analyzed in this manner may be useful as one aspect of the preclinical prediction of AD. Three of the four brain regions important for discriminating Converters from normal controls involve a distributed brain network pertaining to memory, suggesting that this network may be selectively affected in the earliest stages of AD.

Aged↗
PubMed1998

Use of singular value decomposition to characterize age and gender differences in SPECT cerebral perfusion.

UNLABELLED: The main objective of this study was to characterize changes in brain perfusion associated with normal aging and gender. METHODS: Perfusion SPECT images using 99mTc-hexamethyl propyleneamine oxime (HMPAO) were obtained from 152 healthy subjects (67 men, 85 women) aged 50-92 yr. An automated method was developed to objectively assess image data from a large number of brain regions. Image data were reduced with singular value decomposition (SVD), which produced 20 eigenvectors capturing 97.05% of the total information content of 4320 regions from each subject. Subjects were scored individually on each vector. RESULTS: Multivariate analyses demonstrated that there were no significant differences in whole-brain HMPAO uptake with age, but age-related regional declines were seen in lateral ventricular regions. Women had higher HMPAO uptake than men in estimates of global perfusion and regional perfusion in the midcingulate/corpus callosum, inferior temporal and inferior parietal areas. CONCLUSION: These discriminations demonstrate that singular value deomposition of SPECT data may be used to assess differences in perfusion patterns between groups of subjects. They replicate several previous findings, both with respect to age-related changes in perfusion and with respect to gender differences. In addition, they identify a previously unreported gender difference in biparietal regions.

Aged↗
PubMed1996

Citicoline improves verbal memory in aging.

OBJECTIVE: To test the verbal memory of older volunteers given citicoline. DESIGN: A randomized, double-blind, placebo-controlled, parallel group design was employed in the initial study. After data analysis, a subgroup was identified whose members had relatively inefficient memories. These subjects were recruited for a second study that used a crossover design. The subjects took either placebo or citicoline, 1000 mg/d, for 3 months in the initial study. In the crossover study, subjects took both placebo and citicoline, 2000 mg/d, each for 2 months. SUBJECTS: The subjects were 47 female and 48 male volunteers 50 to 85 years old. They were screened for dementia, memory disorders, and other neurological problems. Of the subjects with relatively inefficient memories, 32 participated in the crossover study. MAIN OUTCOME MEASURE: Verbal memory was tested at each study visit using a logical memory passage. Plasma choline concentrations were measured at baseline; at days 30, 60, and 90 in the initial study; and at day 60 of each treatment condition in the crossover study. Plasma choline concentrations and memory scores were analyzed using repeated-measures analysis of variance and covariance, followed by planned comparisons when appropriate. RESULTS: In the initial study, citicoline therapy improved delayed recall on logical memory only for the subjects with relatively inefficient memories. In the crossover study, the higher dosage of citicoline was clearly associated with improved immediate and delayed logical memory. CONCLUSIONS: Citicoline therapy improved verbal memory functioning in older individuals with relatively inefficient memories. Citicoline may prove effective in treating age-related cognitive decline that may be the precursor of dementia.

Aged↗
PubMed1990

Visual neglect during intracarotid amobarbital testing.

The unilateral suppression of hemispheric function by sodium amobarbital may result in hemispatial visual neglect, as measured by performance on a random letter cancellation task. Our study not only investigates this hypothesis but also attempts to identify more precisely the anatomic locus of control for directed attention to extrapersonal space by correlating scanning performance with EEG activity. Forty-eight consecutive patients with epilepsy underwent preoperative intracarotid amobarbital tests. The results indicated that disruption of scanning and contralateral neglect occurred only after right-hemisphere suppression and seemed specifically related to changes in right frontal lobe EEG activity. This pattern of performance held not only for right-handed subjects, but also for those who were left-handed, and even for those who had right-hemisphere language dominance.

Adolescent↗