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Biomedical subjects

F Ostrosky-Solis

Publications and source records attributed to F Ostrosky-Solis.

17 recordsLinked to original sources
PubMed1998

Memory abilities during normal aging.

One hundred and five normal subjects from 20 to 89 years old, and with a minimum of six years of formal education were selected. Subjects were divided into seven age ranges, with 15 subjects in each group. The following tests were individually administered: (1) Wechsler Memory Scale (WMS) (Wechsler, 1945); (2) Serial Verbal Learning (Ardila, Rosselli & Puente, 1994; Ardila & Ostrosky, 1991); (3) The Rey-Osterrieth Complex Figure (ROCF) (Osterrieth, 1944) (copy, immediate, and delayed reproduction); (4) Corsi's blocks (Milner, 1971) (forwards and backwards); and (5) Rivermead Behavioural Memory Test (Wilson, Cockburn, & Baddeley, 1985). This last test may be considered as a functional or ecological memory test. All test scores declined across ages between 4.1% and 76.6%. In all the tests, excepting Digits, standard deviations increased with age. It was observed that the youngest subjects could retain about three-fourths of the information presented, whereas the oldest retained around one-third of this information. About half of the test significantly correlated with the Rivermead Behavioral Memory Test. A factor analysis revealed four different factors accounting for 63.3% of the variance. A single nonverbal memory factor accounted for over 40% of the variance.

Adult↗
PubMed1997

Neuropsychological changes in subjects at risk of inheriting Alzheimer's disease.

Subjects from four Mexican families at risk of inheriting Alzheimer's disease (AD) were studied using a complete neuropsychological battery. These tests were repeated and compared 1 year later. Some of the experimental subjects belong to an international protocol on molecular chromosomal study. A control group matched in age and schooling was included. The subjects at risk underwent a complete physical, neurological and neuropsychological assessment. A neuropsychological battery of cognitive domains designed for the the study of dementia syndromes was administered to all subjects. Six of the subjects showed abnormal performance in cognitive functions, memory, visuospatial functions or language which persisted 1 year later. The present work describes the initial findings of a long-term prospective study aimed at delineating the neuropsychological profile of subjects at risk and to validate subtle abnormalities which in some cases could be the incipient changes of AD.

Adult↗
PubMed1997

ERP assessment of semantic memory in Alzheimer's disease.

This study used the technique of Event-Related Potentials (ERPs), specifically the component N400, to evaluate semantic functions in Alzheimer's disease (AD). ERPs of 10 patients with probable AD and 10 asymptomatic elderly control subjects were recorded during a semantic categorization task using pictures as stimuli, 50% of the stimuli were congruent and the other 50% were incongruent. Significant differences for the incongruent ERPs, with a diminished N400 component, was observed in the patients group whereas the amplitude of the congruent ERPs was similar in both groups. The characteristics of the N400 in the patients with probable AD suggest that there is a lack of efficiency in accessing information and shows that there are deficient associative connections within the semantic network.

Aged↗
PubMed1995

Fetal striatal homotransplantation for Huntington's disease: first two case reports.

Based on the successful use of fetal striatal brain grafting in the restoration of striatal function in rat and nonhuman primate models of Huntington's disease, as well as on the evidence for the clinical potential of fetal brain grafting in the treatment of Parkinson's disease, homotopic fetal striatal homotransplantations were performed in two huntingtonians. Case 1 was a 37 year-old female with moderate to severe Huntington's disease of 9 years evolution; case 2 was a 29 year-old male with mild Huntington's disease of 5 years evolution. Using open microsurgery, each patient was implanted to the ventricular wall of the right caudate nucleus with both striata from a 13 week-old and a 12 week-old human fetus, respectively. Since surgery both patients were kept on cyclosporine A. Surgery produced no damaging effect to either patient. The time course of the neurological progression of their disease, spanning 33 months for case 1, and 16 months for case 2, reveal that the disease in both patients has progressed more slowly in relation to their preoperative state. Although presently it is not possible to determine to what extent, surgery has modified the course of their disease, or if it will continue to have an effect on it, these surgeries represent the first step towards the development of brain grafting for Huntington's disease.

Adult↗
PubMed1991

Visual detectability gradients: effect of illiteracy.

When subjects are required to detect a target pattern presented simultaneously with a number of similar non-target patterns in a brief exposure, marked differences of target detectability are observed as a function of the spatial location of the target (Efron, Yund, & Nichols, 1987, 1990a, b, c; Yund, Efron & Nichols, 1990a, b, c). These differences in detectability as a function of retinal locus, referred to collectively as a "detectability gradient," have been attributed to a central serial processing mechanism, which scans the decaying neural representation of the image. There also is evidence suggesting that, at least in some circumstances, this gradient may be influenced by the direction in which subjects normally read (Heron, 1957; Mishkin & Forgays, 1952; Efron et al., 1987). The object of the present experiment was to determine whether the detectability gradient obtained with the non-linguistic stimuli used in our previous experiments would differ as a function of previous reading experience. The experiment was performed on a group of 60 illiterate subjects and on a socioeconomic-matched group of 60 literate subjects. While the overall accuracy of target detection was identical in the two groups, there were significant differences between the detectability gradients of the literate and illiterate subjects. The nature of these differences indicates that reading, or learning to read, causes the scanning mechanisms of literate subjects to adopt more consistent scan paths, from subject to subject, than they would have adopted without this reading experience.

Adult↗
PubMed1991

Development of human neural transplantation.

The possibility of altering the course of Parkinson's disease by brain grafting is slowly becoming a reality through the efforts of many research groups worldwide. It has been shown that this procedure, as performed in high-level medical research centers, usually produces no permanent adverse effects and can effectively ameliorate parkinsonian signs in certain patients. This progress has served to reinforce our commitment to develop neural transplantation into an effective therapy to treat such a devastating neurodegenerative disease. We have summarized the most important events that have shaped the initial phase of this research. In the course of the last 4 years, considerable knowledge has been gained in the clinical neurosciences regarding the real potential of various brain grafting procedures in treating Parkinson's disease, their shortcomings, and their usefulness in carefully selected patients. There is still no consensus regarding the various fundamental aspects of human brain grafting in Parkinson's disease. Questions concerning surgical technique, candidate selection, the optimal brain regions for implantation, the optimal tissue for implantation, and the real usefulness of brain grafting must be addressed. The importance of the quality of adrenal medulla fragments for grafting, the requirement for immunosuppressors in fetal brain grafting, and the optimal fetal age and the amount of donor tissue for effective grafting are additional areas of concern. The potential of xenografting, preserved tissues, and genetically engineered cells for human brain grafting remain unanswered. The development of human neural transplantation is the responsibility and privilege of neurosurgery.

Animals↗
PubMed1991

Autologous adrenal medullary, fetal mesencephalic, and fetal adrenal brain transplantation in Parkinson's disease: a long-term postoperative follow-up.

We report on the clinical status of 5 patients with Parkinson's disease (PD) 3 years after autologous adrenal medullary (AM)-to-caudate nucleus (CN) implantation, and of 2 PD patients, 2 years after fetal ventral mesencephalon (VM)- and fetal adrenal (A)-to-CN homotransplantation. Current clinical evaluation of 4 of the AM grafted patients revealed sustained bilateral amelioration of their PD signs, most notably of rigidity, postural imbalance and gait disturbances, resulting in a substantial improvement in their quality of life. The disease-related dystonia of one of them disappeared only 2 years after surgery. The levodopa requirements of 2 of these patients and the anticholinergic therapy of another have been reduced. In agreement with the satisfactory clinical evaluation of these 4 patients, their neuropsychological and electrophysiological improvements, initially registered 3 months after surgery, have been maintained for 3 years. After 1 year of significant recovery, the 5th patient of this group has almost returned to her preoperative state. The 2 homotransplanted patients also showed sustained bilateral improvement of their PD signs. Two years after surgery, the most improved signs of the fetal VM case were rigidity, bradykinesia, postural imbalance, gait disturbances and facial expression. The fetal A case has only shown amelioration of rigidity and bradykinesia. Neither of them has shown significant neuropsychological changes. Their current levodopa requirements are less than before surgery. The improvements shown here by PD patients after brain tissue grafts go beyond those obtained using any other therapeutic approach, when levodopa fails. Although more studies and the development of these procedures are obviously required, these initial human trials appear to be resisting the test of time.

Adrenal Glands↗
PubMed1990

Fetal homotransplants (ventral mesencephalon and adrenal tissue) to the striatum of parkinsonian subjects.

Fetal ventral mesencephalon and fetal adrenal tissue grafted to the caudate nucleus of four and three parkinsonian patients, respectively, have been shown to be an alternative treatment for the amelioration of the signs of the disease. The ventral mesencephalon patients had a significant amelioration of rigidity, bradykinesia, postural imbalance, gait disturbance, and facial expression. Three of these four patients have returned to work. The fatal adrenal group only showed amelioration of rigidity and bradykinesia. Though these patients are now able to perform their basic daily living activities, and one of them has renewed her household tasks, the other two have not yet been able to return to work. The differences observed between the ventral mesencephalon- and the fetal adrenal-transplanted patients may be related to the heterogeneity of their disease and/or the type of graft implanted. However encouraging our results may be, this experimental procedure obviously requires further studies, and should not be practiced outside of highly qualified clinical research centers.

Adrenal Glands↗
PubMed1990

The late event related potentials CNV and PINV in normal and dyslexic subjects.

The most prominent ERP to occur during intervals of preparation and anticipation is the contingent negative variation (CNV) or expectancy wave. The resolution of this wave is called the postimperative negative variation (PINV). The purpose of this study was to distinguish the characteristics of the CNV and the PINV in a group of children with reading disabilities or dyslexia and to compare them from a group of normal readers. Nine righthanded boys aged between 10-13 years with reading disabilities were studied. The children were matched with a group of nine normal readers. Four derivations were used: frontal, central, parietal and occipital zones, with reference to linked ears. Data were analyzed using multivariate procedures. Significant differences between groups in CNV amplitude and in PINV amplitude and latency at the left parietal site were observed. We discuss the participation of this zone and we consider processes like expectancy, attention and brain activity signal processing in the differences mentioned.

Adolescent↗
PubMed1989

Detection of brain damage: neuropsychological assessment in a Spanish speaking population.

We developed a neuropsychological battery for assessment of cognitive processes that was standardized in 150 neurologically intact subjects from different socioeducational levels in Mexico City (Ostrosky et al., 1985, 1986). The present study was designed to explore the capacity of this neuropsychological battery to discriminate a brain-injured population from a normal one. Thirty-four patients attending the neurological service of two hospitals institutions in Mexico City were studied. The reasons for going to the hospital included both neurological and neuropsychological symptoms. The group was divided into two subgroups: twenty-four patients who showed brain damage confirmed by brain scans, and ten patients with a normal brain scan. A control group of 19 normal subjects was also studied and paired with the other groups by sex, age and sociocultural level. The results show that the neuropsychological battery was able to recognize 83.3% of the patients with scanographically confirmed brain damage: the total percentage of successful diagnosis was 88.2% and there were no false positives. These results indicate that neuropsychological assessment is a powerful diagnostic procedure that also evaluates the patient's cognitive-behavioral activity and can help to predict the possibilities for rehabilitation and return to work.

Adult↗
PubMed1985

Sociocultural effects in neuropsychological assessment.

The group selected for this evaluation consisted of 109 normal people with an average age of 25, coming from two different sociocultural levels (high and low) of Mexico City. All were completely evaluated by Luria's battery for neuropsychological assessment, adapted by Ardila, Ostrosky, and Canseco, 1981. This group of tests measures nine different areas: Motor Functions, Somatosensory Knowledge, Auditory Knowledge, Visuospatial Knowledge, Cognitive Processes, Language, Reading, Writing and Basic Calculations. For all of these, the higher performance standards were achieved by the subjects from the high sociocultural level. A significant interaction between sociocultural level and sex was observed. The differences between sexes appear only in subjects from the low sociocultural level. Factor analysis of the battery revealed that the most sensitive items to sociocultural level were those related on one hand, to the handling of complex structural and conceptual aspects of language and on the other hand, to the organization of motor sequences and in general motor programming. Research related to the differences found is reviewed and implications for clinical assessment are discussed.

Adult↗
PubMedDate not supplied

[Neuropsychological characteristics of Parkinson's disease].

INTRODUCTION: Form part of the clinical symptoms of Parkinson's disease. These disorders may present in varying degrees: whilst in some patients a clinical picture of dementia is seen, in others there are only specific symptoms. DEVELOPMENT: In this article we consider three of the most controversial aspects currently dominating study of the neuropsychology of Parkinson's disease. The first relates to the pathophysiological basis and neurotransmitters involved. The second deals with the distinction between subcortical-type and Alzheimer-type dementia, and the third with the pathophysiological basis underlying the cognitive profile of the subgroups of patients with Parkinson's disease who do not present dementia. CONCLUSION: The relation between the factors causing the disease, neuropathology, individual variables and the presence of these subgroups requires precise systematic investigation of the neuropsychology shown by patients with Parkinson's disease.

Brain↗
PubMedDate not supplied

[Autograft of the adrenal medulla to caudate nucleus as Parkinson disease treatment: long-term clinical evaluation].

This work presents the long-term evolution (12-27 months) of the patients with adrenomedullary autotransplants to the caudate nucleus for the treatment of Parkinson's disease. Sixteen men and 6 women, mean age of 49.9 years, received brain implants of their own adrenal medulla using the procedure of Madrazo et al. (1). Nineteen of the transplanted patients suffered idiopathic Parkinson's disease and 3 of them parkinsonism. Before surgery 20 patients were on L-dopa and suffered collateral signs due to the drug. The degree of severity of their disease was evaluated pre and postoperatively, with and without medication, in their "on" and "off" periods, using the international scales of Schwab and England, Hoehn and Yahr, Madrazo, and the UPRS, and was documented by videotape. Biochemical analyses were made of lumbar and ventricular cerebrospinal fluid, and neuropsychological and neurophysiological evaluations were performed before and after surgery. In some patients, the location and viability of the adrenal medullary implants were demonstrated by brain scintigraphy using 131-I-metaiodobenzylguanidine, a chromaffin specific radiopharmaceutical. The clinical evaluations of 18 autotransplanted patients (4 died) showed their significant functional recovery both in their "on" and "off" periods, that for the first patients operated has remained stable for 27 months. Also, their response to L-dopa improved allowing the reduction of their postoperative doses of medication to 30% of their preoperative requirements, with the disappearance of the collateral effects of the drug.

Acetylcholinesterase↗
PubMedDate not supplied

[The first homotopic fetal homograft of the striatum in the treatment of Huntington's disease].

Fetal brain grafting has been used successfully in the restoration of striatal function in rat and non human primate models of Huntington's disease (HD). This is a report of the first clinical trial of this procedure applied to a 37 year old Mexican female with moderate to severe HD of 9 years evolution. The two striata from a 13 week-old human fetus were homotopically transplanted to 4 cavities in the ventricular wall of the right caudate nucleus. The months after surgery, her neurologic and neuropsychologic evaluations revealed the stabilization of many of her signs and most neuropsychologic parameters, a moderate improvement of her choreic movements, predominantly in the face, of her ability to define and express ideas in oral and written form, and of her articulatory agility, as well as of some activities of her daily life and social behavior. There was a slight deterioration of her gait and posture. Her saccadic system and optokinetic nystagmus, and her visuospatial and visuoperceptual functions were deteriorated.

Adult↗