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PubMed1996

Performance of the 'unaffected' upper extremity of elderly stroke patients.

BACKGROUND AND PURPOSE: The main objective of this study was to compare the sensorimotor performance of the unaffected upper extremity (UE) of elderly stroke patients with that of healthy elderly people. METHODS: The group of stroke patients was composed of 43 hemiplegic/paretic subjects who had had a cerebrovascular accident at least 6 months earlier. They were > or = 60 years old, were right-handed before the stroke, had visual perception within normal limits, and showed no major cognitive impairments. A group of 43 healthy subjects matched for dominance, age, and sex was used for comparison. The main parameters of the performance of the unaffected UE of the stroke subjects and of the same side of the healthy subjects were measured with valid, reliable instruments. Some variables potentially related to the unaffected UE were also measured: affected UE motor function, functional independence, length of time since the stroke, self-perceived health status, activity level, and hand anthropometry. RESULTS: Statistical analyses showed significant deficits in the unaffected UE of hemiplegic/paretic subjects compared with normal subjects with regard to the following parameters: gross manual dexterity, fine manual dexterity, motor coordination, global performance, and kinesthesia (P < .01 to P < .0001). No significant clinical or statistical difference was found for grip strength (P < .81), static and moving two-point discrimination (P = .21 and P = .12), or touch/pressure threshold (P < .91). CONCLUSIONS: Many factors (frequency of use of the unaffected hand, sensorimotor interaction tasks, severity of the deficits in corticifugal projections, and deficits in postural stabilization) could interact to provide the clinical picture obtained in the present study.

Aged↗
PubMed1999

Forced use of the upper extremity in chronic stroke patients: results from a single-blind randomized clinical trial.

BACKGROUND AND PURPOSE: Of all stroke survivors, 30% to 66% are unable to use their affected arm in performing activities of daily living. Although forced use therapy appears to improve arm function in chronic stroke patients, there is no conclusive evidence. This study evaluates the effectiveness of forced use therapy. METHODS: In an observer-blinded randomized clinical trial, 66 chronic stroke patients were allocated to either forced use therapy (immobilization of the unaffected arm combined with intensive training) or a reference therapy of equally intensive bimanual training, based on Neuro-Developmental Treatment, for a period of 2 weeks. Outcomes were evaluated on the basis of the Rehabilitation Activities Profile (activities), the Action Research Arm (ARA) test (dexterity), the upper extremity section of the Fugl-Meyer Assessment scale, the Motor Activity Log (MAL), and a Problem Score. The minimal clinically important difference (MCID) was determined at the onset of the study. RESULTS: One week after the last treatment session, a significant difference in effectiveness in favor of the forced use group compared with the bimanual group (corrected for baseline differences) was found for the ARA score (3.0 points; 95% CI, 1.3 to 4.8; MCID, 5.7 points) and the MAL amount of use score (0.52 points; 95% CI, 0.11 to 0.93; MCID, 0.50). The other parameters revealed no significant differential effects. One-year follow-up effects were observed only for the ARA. The differences in treatment effect for the ARA and the MAL amount of use scores were clinically relevant for patients with sensory disorders and hemineglect, respectively. CONCLUSIONS: The present study showed a small but lasting effect of forced use therapy on the dexterity of the affected arm (ARA) and a temporary clinically relevant effect on the amount of use of the affected arm during activities of daily living (MAL amount of use). The effect of forced use therapy was clinically relevant in the subgroups of patients with sensory disorders and hemineglect, respectively.

Activities of Daily Living↗
PubMed2001

The ABILHAND questionnaire as a measure of manual ability in chronic stroke patients: Rasch-based validation and relationship to upper limb impairment.

BACKGROUND AND PURPOSE: Chronic hemiparetic patients often retain the ability to manage activities requiring both hands, either through the use of the affected arm or compensation with the unaffected limb. A measure of this overall ability was developed by adapting and validating the ABILHAND questionnaire through the Rasch measurement model. ABILHAND measures the patient's perceived difficulty in performing everyday manual activities. METHODS: One hundred three chronic (>6 months) stroke outpatients (62% men; mean age, 63 years) were assessed (74 in Belgium, 29 in Italy). They lived at home and walked independently and were screened for the absence of major cognitive deficits (dementia, aphasia, hemineglect). The patients were administered the ABILHAND questionnaire, the Brunnström upper limb motricity test, the box-and-block manual dexterity test, the Semmes-Weinstein tactile sensation test, and the Geriatric Depression Scale. The brain lesion type and site were recorded. ABILHAND results were analyzed with the use of Winsteps Rasch software. RESULTS: The Rasch refinement of ABILHAND led to a change from the original unimanual and bimanual 56-item, 4-level scale to a bimanual 23-item, 3-level scale. The resulting ability scale had sufficient sensitivity to be clinically useful. Rasch reliability was 0.90, and the item-difficulty hierarchy was stable across demographic and clinical subgroups. Grip strength, motricity, dexterity, and depression were significantly correlated with the ABILHAND measures. CONCLUSIONS: The ABILHAND questionnaire results in a valid person-centered measure of manual ability in everyday activities. The stability of the item-difficulty hierarchy across different patient classes further supports the clinical application of the scale.

Adult↗
PubMed1994

Selected motor skills of mentally retarded and nonretarded individuals.

The aim of this study was to examine whether mentally retarded individuals show a specific motor performance deficit on measures of reaction time, aiming, and dexterity. 23 mentally retarded adolescents and two control groups of 22 non-retarded persons of the same mental age and 20 nonretarded persons of the same chronological age were tested. Motor performance measures for retarded persons were considerably longer than those of nonretarded persons of the same chronological age and of the same mental age. Only time of finger dexterity with short pins was longer for the retarded than for the nonretarded adolescents of the same mental age. Reaction times across groups were faster for the sound than for the light signal. No difference in RT for fine movement was observed. Differences among the various motor performance measures for retarded and nonretarded subjects are confirmed.

Adolescent↗
PubMed1993

Surgical glove perforations in otolaryngology: prevention with cut-resistant gloves.

This study examines the role of cut-resistant, "orthopedic-type" gloves in prevention of exposure of surgical personnel to infectious body fluids through surgical glove perforation. The incidence of glove perforations in 12 consecutive cases of intermaxillary fixation (IMF) was studied. Surgeons were double-gloved with standard latex gloves and wore cut-resistant gloves between the outer and inner gloves. As controls, six cadaver heads were wired into IMF with surgeons double-gloving without the cut-resistant glove. The rates of latex glove perforation were then compared between the two groups. Fifty-three percent (32 of 60) of outer latex gloves, but no inner latex gloves (0 of 50) were perforated when surgeons wore cut-resistant gloves. In the control group, 45% of outer gloves (9 of 20) and 15% of inner gloves (3 of 20) were perforated. The difference of inner glove perforations--hence cutaneous exposure--between these two groups was statistically significant (p < 0.01). The use of cut-resistant gloves in addition to double-gloving with latex surgical gloves is recommended for facial plastic and reconstructive procedures with metal implants and major head and neck surgery, because these operations have a high rate of glove perforation. Because some loss of dexterity is noted when cut-resistant gloves are worn, the risk of glove perforation must be weighted against the need for optimal dexterity.

Equipment Design↗
PubMed2003

The impact of ulnar nerve compression at the elbow on the hand function of heavy manual workers.

The objectives of this article were to study the impact of the hand function disability due to ulnar neuropathy at the elbow (UNE) on workers engaged in occupations requiring heavy hand use. Four patients (42.5 +/- 7 years old), all engaged in heavy-duty jobs, with severe conduction block but without severe axonal loss were recruited. The severity of ulnar nerve compression was quantified based on electrophysiologic studies, Jebsen-Taylor Hand Function Test, Jamar dynamometer, and Semmes-Weinstein Monofilaments Test. UNE resulted in a reduction in hand strength without any significant impact on fine motor dexterity. The 4 laborers whose work required strong hand grip found this debilitating. Severe UNE affects the hand function of heavy manual workers by impeding their grip and pinch strengths. However, UNE does not affect tasks requiring fine hand dexterity.

Adult↗
PubMedDate not supplied

Behavioral evaluation of hemiparkinsonian MPTP monkeys following dopamine pharmacological manipulation and adrenal co-graft transplantation.

Bradykinesia and rigidity are the symptoms that most directly correlate with loss of striatal dopamine in Parkinson's disease. In the hemiparkinsonian (HP) monkey, this is represented by paucity of movement as measured by coli puterized movement analysis, diminished manual dexterity on clinical examination, and diminished performance on operant behavioral tasks. The present study used an MPTP-induced HP model in rhesus monkeys to evaluate the effectiveness of adrenal medullary and peripheral nerve co-grafts in diminishing parkinsonian symptoms. Unoperated controls (N = 4), surgical controls with caudate lesioning (N = 4), and caudate co-grafted (N = 4) HP monkeys demonstrated diminished movement in the home cage following MPTP. This behavior persisted in unoperated controls, but improved in both surgical control and co-grafted monkeys. Functional hand dexterity evaluations demonstrated similar impairment in all three groups but only surgical controls and co-grafted monkeys demonstrated improvement. In general, rotational behavior in response to apomorphine was consistent with recovery of function in surgical controls and co grafted monkeys, but marked between-subject variability precluded group statistical analyses. None of the monkeys could perform the operant task using the affected limb following MPTP. However, the performance of two co-grafted animals demonstrated partial recovery. L-dopa improved operant performance, demonstrating a dopaminergic component to the task. The results demonstrate recovery of behavioral function after surgical treatment, with adrenal co-grafted monkeys showing the greatest degree of improvement.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1998

Comparing the ability of various compositive outcomes to discriminate treatment effects in MS clinical trials. The Multiple Sclerosis Collaborative Research Group (MSCRG).

We compared the ability of the Kurtzke Expanded Disability Status Scale (EDSS) and a composite outcome of non-physician-based measures of time to ambulate 25 feet (TA) and manual dexterity (the Box and Block Test [BBT], and 9-Hole Peg Test [9HPT]) to discriminate treatment effects in the Phase III study of interferon beta-1a. A log-rank comparison of Kaplan-Meier curves by treatment group showed the non-physician-based composite of BBT, 9HPT, and TA was of comparable sensitivity (P = 0.013) in discriminating sustained treatment failure as the EDSS alone (P = 0.029). The composite of BBT, 9HPT, TA, and EDSS was more sensitive (P = 0.009) in discriminating sustained treatment failure than the EDSS alone. Compositive outcomes of the EDSS and non-physician-based measures of manual dexterity and timed ambulation provide an appealing strategy to reduce the number of patients required to discriminate treatment effects in MS clinical trials.

Clinical Trials as Topic↗
PubMed2004

The effects of constraint-induced therapy on precision grip: a preliminary study.

OBJECTIVE: This preliminary study examines the effects of a 2-week constraint-induced therapy (CIT) intervention on the force-producing capabilities of the hemiparetic hand during the performance of a functional dexterous manipulation task. METHODS: A 6-degree-of-freedom force/torque transducer that was embedded into the handle of a key allowed for the quantification of grasping forces and torques produced during the performance of a functional key-turning task. Clinical and kinetic data were collected from 10 subacute patients (3-9 months poststroke) who were participating in an ongoing national clinical study (EXCITE trial) examining the effects of CIT on upper extremity motor performance. Investigators were blinded to treatment designation. Five patients receiving treatment immediately completed 2 weeks of intensive CIT, whereas a group randomized to treatment 1 year later did not receive any therapy during a similar 2-week span. RESULTS: . Results indicated that 4 of the 5 patients in the CIT group, compared to the delayed group, showed significant clinical improvements in hand function, increased maximum precision grip force, improved force and torque regulation, and reduced variability in rate of force production during task performance. CONCLUSIONS: Improved force control may be a mechanism contributing to the observed improvements in dexterous function in those patients undergoing CIT.

Chronic Disease↗
PubMed2004

Gender differences in the relation of hypertension to cognitive function in older adults.

Here we examined potential interactive relations of hypertension and gender to cognitive function in 98 healthy, older adults (ages 55-83 years; 64% male; 92% White). After statistical adjustment for age and education, hypertensives performed significantly more poorly than normotensives on tests of motor speed and manual dexterity (p < 0.05). The adverse consequences of hypertension in older adults was more pronounced for female than male hypertensives on tests of delayed visual memory, visual attention and working memory, visuoconstructional ability, motor speed and manual dexterity for the non-dominant hand (p < 0.05); these are dimensions of performance for which female gender may be a relative disadvantage. The findings suggest the need to further examine subgroups that are vulnerable to the cognitive correlates of hypertension. The results also highlight the need for increased attention to blood pressure control in older adults for the preservation of cognitive function.

Aged↗
PubMed2004

A multiple case design experiment to investigate the performance and neural effects of a programme for training hand function after stroke.

OBJECTIVE: To investigate the effects of task-specific practice on hand function in stroke subjects who were given computer-assisted training and to look for associated changes in corticospinal connectivity. DESIGN: Single case design experiments. SETTING: Subjects' homes. SUBJECTS: Seven chronic stroke subjects with impaired hand function. INTERVENTIONS: Daily intensive practice of fast and accurate force changes in pinch grip and knob turning grip for four weeks. MAIN MEASURES: Pinch and power grip strength and dexterity measured using the Ten-hole Peg Test and a timed nuts and bolts test were recorded twice a week throughout the study. Corticospinal connectivity was assessed by latency of electromyography (EMG) responses to transcranial magnetic stimulation (TMS) recorded during the baseline weeks before the training and again immediately after the training period. RESULTS: Subjects completed between 5760 and 18560 force changes. Clinically relevant improvements in grip strength were evident in only two subjects. None of the subjects showed clinically significant improvement in dexterity measures. Statistical analysis showed that improved performance was related to the training phase in only two subjects. A reduction in latency of EMG responses to TMS was seen in two subjects but could not be attributed to the training phase. CONCLUSIONS: The intensive training did not improve hand function in most subjects. Latencies of EMG responses to TMS were also unable to detect any change.

Aged↗
PubMed2006

The effect of a task-oriented intervention on arm function in people with stroke: a randomized controlled trial.

OBJECTIVE: To evaluate the efficacy of a task-oriented intervention in enhancing arm function in people with stroke. DESIGN: Two-centre, observer-blinded, stratified, block-randomized controlled trial. SETTING: General community. PATIENTS: Ninety-one individuals within one year of a first or recurrent stroke consented to participate between May 2000 and February 2003. INTERVENTIONS: The experimental intervention involved practice of functional, unilateral and bilateral tasks that were designed to improve gross and fine manual dexterity whereas the control intervention was composed of walking tasks. Members in both groups participated in three sessions a week for six weeks. MAIN OUTCOME MEASURE(S): The primary test of arm function was the Box and Block Test. Secondary tests included the Nine-Hole Peg Test, maximal grip strength, the Test d'Evaluation des Membres supérieurs des Personnes Agées (TEMPA) and the Stroke Rehabilitation Assessment of Movement. RESULTS: Results are for the more affected arm. Baseline performance on the Box and Block Test was an average of 26 blocks (standard deviation (SD) = 16) in the experimental group (n = 47) and 26 blocks (SD = 18) in the control group (n = 44). These values represent approximately 40% of age-predicted values. Values for the postintervention evaluation were an average of 28 (SD = 17) and 28 (SD = 19) blocks for the experimental and control group respectively. No meaningful change on other measures of arm function was observed. CONCLUSIONS: A task-oriented intervention did not improve voluntary movement or manual dexterity of the affected arm in people with chronic stroke.

Activities of Daily Living↗
PubMed2005

Diagnosis of hypertension and high blood pressure levels negatively affect cognitive function in older adults.

BACKGROUND: Hypertension is associated with diminished performance on tests of cognitive function. The degree to which those diagnosed with hypertension have controlled blood pressure (BP) levels may be a critical determinant of cognitive outcomes. Persons with hypertension and poorly controlled BP are likely to display the worst performance on cognitive tests. PURPOSE: The purpose is to examine potential interactive relations of hypertension diagnostic status and current BP levels to cognitive function. METHODS: Participants were 101 healthy older adults (ages 53-84, 62% male, 90% White, 29% diagnosed with hypertension) who engaged in biomedical and neuropsychological assessment. RESULTS: After statistical adjustment for age and education, persons with high BP performed more poorly than those with normal BP on the Visual Reproductions-Immediate and Delayed Recall and the Grooved Pegboard tests. Diagnosed hypertension was related to poorer performance on the Grooved Pegboard tests. An interaction of diagnosed hypertension and BP level revealed that those diagnosed with hypertension and also having poorly controlled BP levels performed least well on the Grooved Pegboard tests and the Trail Making Test-Part A. CONCLUSION: Irrespective of prior diagnostic status, individuals with high BP displayed compromised performance on tests of nonverbal memory, motor speed, and manual dexterity. However, as compared to the other groups, those diagnosed with hypertension and also having poorly controlled BP elevation were most vulnerable to difficulties on tests of perceptuo-motor speed, motor speed, and manual dexterity. These findings suggest the need for increased attention to preventative efforts with respect to BP assessment and control in older adults to help preserve cognitive function.

Aged↗
PubMed2000

Spinocerebellar ataxia type 8: clinical features in a large family.

OBJECTIVE: To compare the clinical and genetic features of the seven-generation family (MN-A) used to define the spinocerebellar ataxia 8 (SCA8) locus. BACKGROUND: The authors recently described an untranslated CTG expansion that causes a novel form of SCA (SCA8) characterized by reduced penetrance and complex patterns of repeat instability. METHODS: Clinical and molecular features of 82 members of the MN-A family were evaluated by neurologic examination, quantitative dexterity testing, and, in some individuals, MRI and sperm analyses. RESULTS: SCA8 is a slowly progressive, predominantly cerebellar ataxia with marked cerebellar atrophy, affecting gait, swallowing, speech, and limb and eye movements. CTG tracts are longer in affected (mean = 116 CTG repeats) than in unaffected expansion carriers (mean = 90, p < 10-8). Quantitative dexterity testing did not detect even subtle signs of ataxia in unaffected expansion carriers. Surprisingly, all 21 affected MN-A family members inherited an expansion from their mothers. The maternal penetrance bias is consistent with maternal repeat expansions yielding alleles above the pathogenic threshold in the family (>107 CTG) and paternal contractions resulting in shorter alleles. Consistent with the reduced penetrance of paternal transmissions, CTG tracts in all or nearly all sperm (84 to 99) are significantly shorter than in the blood (116) of an affected man. CONCLUSIONS: The biologic relationship between repeat length and ataxia indicates that the CTG repeat is directly involved in SCA8 pathogenesis. Diagnostic testing and genetic counseling are complicated by the reduced penetrance, which often makes the inheritance appear recessive or sporadic, and by interfamilial differences in the length of a stable (CTA)n tract preceding the CTG repeat.

Adult↗
PubMed2003

Neuropsychological effects of third ventricle tumor surgery.

OBJECTIVE: This study assessed the neuropsychological outcome of patients after surgical treatment for third ventricle brain tumors. Neuropsychological consequences of surgical intervention can have a major impact on patients' quality of life and therefore have important implications for treatment planning. METHODS: A retrospective analysis of 33 patients' neuropsychological data was performed. All patients received a comprehensive neuropsychological evaluation after treatment for a primary brain tumor in the third ventricular region. Twenty-six patients underwent surgery, 14 via the transcallosal approach and 12 via a subfrontal, left transcortical, right pterional, or infratentorial supracerebellar approach. Seven patients were not treated by surgical intervention. RESULTS: There was a significantly elevated frequency of cognitive impairment relative to normative values in memory, executive functioning, and fine manual speed and dexterity. There were no differences in mean neuropsychological scores between patients who underwent surgery and those who did not. There were no differences in mean performance on the basis of surgical approach, tumor infiltration, or history of cranial irradiation. Repeated measures data available for two patients revealed memory impairment before and after surgery, and one patient experienced major improvement after surgery on a measure of mental flexibility and problem solving. CONCLUSION: Patients with third ventricle tumors are at risk for developing impairments in memory, executive function, and fine manual speed and dexterity, which are domains associated with frontal subcortical functions. In the current study, different types of treatment were not associated with differential cognitive sequelae, and surgical intervention did not account for cognitive deficits.

Adolescent↗
PubMed2004

Surgical robotics: a review and neurosurgical prototype development.

PURPOSE: The purpose of this article is to update the neurosurgical community on the expanding field of surgical robotics and to present the design of a novel neurosurgical prototype. It is intended to mimic standard technique and deploy conventional microsurgical tools. The intention is to ease its integration into the "nervous system" of both the traditional operating room and surgeon. CONCEPT: To permit benefit from updated intraoperative imaging, magnetic resonance imaging-compatible materials were incorporated into the design. Advanced haptics, optics, and auditory communication with the surgical site recreate the sight, sound, and feel of neurosurgery. RATIONALE: Magnification and advanced imaging have pushed surgeons to the limit of their dexterity and stamina. Robots, in contrast, are indefatigable and have superior spatial resolution and geometric accuracy. The use of tremor filters and motion scalers permits procedures requiring superior dexterity. DISCUSSION: Breadboard testing of the prototype components has shown spatial resolution of 30 microm, greatly exceeding our expectations. Neurosurgeons will not only be able to perform current procedures with a higher margin of safety but also must speculate on techniques that have hitherto not even been contemplated. This includes coupling the robot to intelligent tools that interrogate tissue before its manipulation and the potential of molecular imaging to transform neurosurgical research into surgical exploration of the cell, not the organ.

Artificial Intelligence↗
PubMed1993

Enrichment and characterization of thymus-repopulating cells in stroma-dependent cultures of rat bone marrow.

The bone marrow precursor cells seeding the thymus have been difficult to investigate using fresh bone marrow and in vivo thymus reconstitution assays. We have therefore designed a short-term bone marrow culture system allowing the study of thymus-repopulating cells in the marrow microenvironment. Low-density rat bone marrow cells were grown on pre-established mouse bone marrow stromal cell layers. Cocultured cells were maintained either under steroid-free conditions (Whitlock/Witte-type culture) or in the presence of 10(-7) M hydrocortisone (Dexter-type culture). After 3 days in vitro, the unanchored cell fractions were tested for their ability to colonize and repopulate fetal mouse thymic lobes in vitro. Both fresh low-density cells and Whitlock/Witte-type cultures, but not Dexter-type cultures, gave rise intrathymically to significant numbers of rat donor-type Thy-1.1high CD2+ CD5low CD43+ cells accounting for 50% to 90% of the organ-cultured cells at day 14. Repopulation of fetal mouse thymic lobes by rat Thy-1.1high cells could be used as a readout assay for initiation of thymopoiesis from bone marrow precursor cells, since 90% of the cells were CD3-/low and TCR alpha beta-/low and 15% of the cells co-expressed CD4 and CD8. Dose-response analysis showed that thymus repopulating cells were at least maintained, if not amplified during the 3-day culture period, leading to at least a 10-fold enrichment as compared to unfractionated bone marrow. Unlike fresh low-density cells before culture, short-term Whitlock/Witte-type cultures were depleted in myeloid-restricted precursor cells. In culture, the thymus-repopulating activity was predominantly associated with a 10% lymphoid cell subset which did not express the B-lineage-associated antigens revealed by HIS24 (the rat B220 equivalent) and HIS50 mAbs. We propose that unanchored thymus-repopulating cells enriched in Whitlock/Witte-type cultures may represent lymphoid-restricted, T-cell precursors of the bone marrow capable of emigrating and colonizing the thymus.

Animals↗
PubMed2002

Protein kinase C activity and the relations between blood lead and neurobehavioral function in lead workers.

At picomolar concentrations, lead activates protein kinase C (PKC). This activation has been implicated in the neurotoxicity of lead. No prior study has evaluated the association of PKC activity with neurobehavioral function in humans. The purpose of this study was to determine whether PKC activity is associated with neurobehavioral function or modifies the relationship between blood lead levels and neurobehavioral test scores. In this cross-sectional study of 212 current lead workers in the Republic of Korea, we assessed blood lead levels, neurobehavioral test scores, and PKC activity. PKC activity was determined by measuring the levels of phosphorylation of three erythrocyte membrane proteins (spectrin and the 52-kDa and 48-kDa subunits of band 4.9), using an in vitro back-phosphorylation assay. When linear regression was used to control for confounding variables, blood lead was a significant predictor of decrements in performance on tests of psychomotor function, manual dexterity, and executive ability. In linear regression models, back-phosphorylation levels were not associated with neurobehavioral test scores, but when dichotomized at the median, back-phosphorylation levels modified the relationship between blood lead and test scores. For spectrin and the 52-kDa and 48-kDa subunits of band 4.9, 5, 2, and 5 of 14 interaction terms, respectively, had associated p-values less than 0.10, all with positive signs, indicating that blood lead was associated with worse test scores only in subjects with lower back-phosphorylation levels. These data indicate that blood lead levels are associated with decrements in neurobehavioral test scores, mainly in the domains of manual dexterity and psychomotor function, but only in subjects with lower in vitro back-phosphorylation levels, which is equivalent to higher in vivo PKC activity. We hypothesize that subjects with higher PKC activity in the presence of lead may be more susceptible to the health effects of lead.

Adult↗