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PubMed2005

Percutaneous coronary intervention: recommendations for good practice and training.

Cardiologists undertaking percutaneous coronary intervention (PCI) are excited by the combination of patient and physician satisfaction and technological advance occurring on the background of the necessary manual dexterity. Progress and applicability of percutaneous techniques since their inception in 1977 have been remarkable; a sound evidence base coupled with the enthusiasm and ingenuity of the medical device industry has resulted in a sea change in the treatment of coronary heart disease (CHD), which continues to evolve at breakneck speed. This is the third set of guidelines produced by the British Cardiovascular Intervention Society and the British Cardiac Society. Following the last set of guidelines published in 2000, we have seen PCI activity in the UK increase from 33,652 to 62,780 (87% in four years) such that the PCI to coronary artery bypass grafting ratio has increased to 2.5:1. The impact of drug eluting stents has been profound, and the Department of Health is investigating the feasibility of primary PCI for acute myocardial infarction. Nevertheless, the changes in the structure of National Health Service funding are likely to focus our attention on cost effective treatments and will require physician engagement and sensitive handling if we are to continue the rapid and appropriate growth in our chosen field. It is important with this burgeoning development now occurring on a broad front (in both regional centres and district general hospitals) that we maintain our vigilance on audit and outcome measures so that standards are maintained for both operators and institutions alike. This set of guidelines includes new sections on training, informed consent, and a core evidence base, which we hope you will find useful and informative.

Angioplasty, Balloon, Coronary↗

PubMed2005

Do wrist guards have the potential to protect against wrist injuries in bicycling, micro scooter riding, and monkey bar play?

OBJECTIVE: To test the potential of wrist guards to prevent wrist injury in recreational activities that require good grip strength and hand dexterity. METHODS: Forty eight children aged 5-8 years from one Melbourne school volunteered for tests chosen or devised following a review of the literature on the effects of orthoses use and hand function. RESULTS: Wrist guard wearing significantly degraded grip strength, bicycle steering, and performance on a monkey bar. Micro scooter steering was not significantly affected by their use. CONCLUSION: Wrist guards designed for skating are not recommended for bicycle riding and playing on climbing apparatus, and their suitability for scooter riding requires further investigation.

Bicycling↗

PubMed2000

Laser capture microdissection in pathology.

The molecular examination of pathologically altered cells and tissues at the DNA, RNA, and protein level has revolutionised research and diagnostics in pathology. However, the inherent heterogeneity of primary tissues with an admixture of various reactive cell populations can affect the outcome and interpretation of molecular studies. Recently, microdissection of tissue sections and cytological preparations has been used increasingly for the isolation of homogeneous, morphologically identified cell populations, thus overcoming the obstacle of tissue complexity. In conjunction with sensitive analytical techniques, such as the polymerase chain reaction, microdissection allows precise in vivo examination of cell populations, such as carcinoma in situ or the malignant cells of Hodgkin's disease, which are otherwise inaccessible for conventional molecular studies. However, most microdissection techniques are very time consuming and require a high degree of manual dexterity, which limits their practical use. Laser capture microdissection (LCM), a novel technique developed at the National Cancer Institute, is an important advance in terms of speed, ease of use, and versatility of microdissection. LCM is based on the adherence of visually selected cells to a thermoplastic membrane, which overlies the dehydrated tissue section and is focally melted by triggering of a low energy infrared laser pulse. The melted membrane forms a composite with the selected tissue area, which can be removed by simple lifting of the membrane. LCM can be applied to a wide range of cell and tissue preparations including paraffin wax embedded material. The use of immunohistochemical stains allows the selection of cells according to phenotypic and functional characteristics. Depending on the starting material, DNA, good quality mRNA, and proteins can be extracted successfully from captured tissue fragments, down to the single cell level. In combination with techniques like expression library construction, cDNA array hybridisation and differential display, LCM will allow the establishment of "genetic fingerprints" of specific pathological lesions, especially malignant neoplasms. In addition to the identification of new diagnostic and prognostic markers, this approach could help in establishing individualised treatments tailored to the molecular profile of a tumour. This review provides an overview of the technique of LCM, summarises current applications and new methodical approaches, and tries to give a perspective on future developments. In addition, LCM is compared with other recently developed laser microdissection techniques.

Cell Adhesion↗

PubMed2004

Visual disturbances representing occipital lobe epilepsy in patients with cerebral calcifications and coeliac disease: a case series.

Paroxysmal visual manifestations may represent epileptic seizures arising from the occipital lobe. In coeliac disease (CD) bilateral occipital calcifications and seizure semiology consistent with an occipital origin have been described, primarily in Mediterranean countries. By reporting three adult patients from an Australian outpatient clinic with visual disturbances, occipital cerebral calcifications, and CD, this study seeks to emphasise that CD should be considered even when patients of non-Mediterranean origin present with these symptoms. Seizure types included simple partial, complex-partial, and secondarily generalised seizures. The seizure semiology consisted of visual disturbances such as: blurred vision, loss of focus, seeing coloured dots, and brief stereotyped complex visual hallucinations like seeing unfamiliar faces or scenes. Symptoms of malabsorption were not always present. Neurological examination was unremarkable in two patients, impaired dexterity and mild hemiatrophy on the left was noted in one. Routine electroencephalography was unremarkable. In all cases, computed tomography demonstrated bilateral cortical calcification of the occipital-parietal regions. Magnetic resonance imaging showed no additional lesion. All patients had biopsy confirmed CD. Seizure control improved after treatment with gluten free diet and anticonvulsants. This report illustrates the association between seizures of occipital origin, cerebral calcifications, and CD even in patients not of Mediterranean origin.

Adult↗

PubMed2005

White matter hyperintensities are related to physical disability and poor motor function.

OBJECTIVE: To determine the impact of white matter hyperintensities (WMHs) on physical health and cognitive function in 60-64 year old individuals residing in the community. METHODS: A subsample of 478 persons aged 60-64 from a larger community sample underwent brain magnetic resonance imaging (MRI) scans. WMHs on T2 weighted FLAIR (fluid attenuated inversion recovery) MRI scans were assessed using an automated procedure. Subjects were assessed for global cognitive function, episodic memory, working memory (digit span), information processing speed (Symbol Digit Modalities Test; SDMT), fine motor dexterity (Purdue Pegboard), and grip strength, and completed the Physical Component Summary of the Short Form Health Survey (SF-12). Regression analyses were used to examine the effect of WMHs on physical and cognitive function. RESULTS: Deep and periventricular WMHs were present in all subjects, with women having slightly more lesions than men. WMHs were significantly associated with poorer reported physical health on the SF-12 scale, after adjusting for depression, cognitive function, and brain atrophy. WMHs were also related to lower scores on the Purdue Pegboard test, grip strength, choice reaction time, and SDMT, but not on tests of episodic memory, working memory, general intellectual function, and global cognitive function. On regression analyses, the Purdue Pegboard test and grip strength were related to physical disability. CONCLUSION: WMHs are common, albeit mild, in middle adult life. They are associated with physical disability, possibly through reduced speed, fine motor coordination, and muscular strength. They are also related to slowed information processing speed but not other cognitive functions.

Automation↗

PubMed2005

A syndromal analysis of neuropsychological outcome following coronary artery bypass graft surgery.

BACKGROUND: Studies of neuropsychological outcome following coronary artery bypass graft surgery (CABG) have traditionally dichotomised patients as "impaired" or "unimpaired". This conceals the potential heterogeneity of deficits due to different mechanisms and sites of brain injury. OBJECTIVES: To explore neuropsychological outcome following CABG and determine to what extent it conforms to prototypic cortical and/or subcortical neurobehavioral syndromes and whether different intraoperative physiologic measures are associated with different subtypes of neuropsychological outcome. METHODS: Neuropsychological tests were administered to 85 patients before and after elective CABG and to 50 matched normal control subjects. Pre- to postoperative change scores were computed using standardised regression based norms. Change scores on selected memory measures were subjected to cluster analysis to identify qualitatively distinct subtypes of memory outcome. Emergent clusters were compared on non-memory measures, intraoperative physiologic measures, and demographic variables. RESULTS: Three subtypes of memory outcome were identified: memory spared (48% of patients), retrieval deficit (35%), and encoding/storage deficit (17%). Contrary to expectation, the subgroups were indistinguishable on measures of confrontation naming and manual dexterity and on intraoperative cardiac surgical physiologic measures and demographic variables. The encoding/storage deficit subgroup exhibited executive dysfunction. CONCLUSIONS: Heterogeneous profiles of neuropsychological dysfunction were found following CABG although they did not tightly conform to prototypic cortical and subcortical neurobehavioral syndromes. This challenges the value and appropriateness of the common practice of collapsing individual test scores to arrive at a single figure to define "impairment". Whether different subtypes of neuropsychological outcome are caused by different pathophysiologic mechanisms remains unknown.

Aged↗

PubMed2006

Patients with horizontal gaze palsy and progressive scoliosis due to ROBO3 E319K mutation have both uncrossed and crossed central nervous system pathways and perform normally on neuropsychological testing.

BACKGROUND: Horizontal gaze palsy and progressive scoliosis (HGPPS) is caused by mutations of the ROBO3 gene, which encodes a receptor associated with axonal guidance during development. Although there is evidence for uncrossed cuneatal and corticospinal tracts in HGPPS, it is unclear whether other central nervous system pathways are involved. OBJECTIVE: To study two patients with HGPPS homozygotic for the ROBO3 E319K mutation using a variety of neurophysiological and neuropsychological tests. METHODS: A battery of neuropsychological tests was applied to assess various cognitive and perceptual functions. The corticospinal, somatosensory and auditory pathways were evaluated using appropriate neurophysiological tests. To access motor pathways to the neck muscles, electromyographic recordings were obtained from the sternocleidomastoideus and splenius capitis muscle during active head rotation. RESULTS: Both patients performed normally on manual dexterity, complex sensory and visuospatial functions, reading and general intelligence tests. Motor evoked potentials in both patients showed uncrossed corticospinal tracts for the extremities, although in one patient, electromyography indicated pyramidal tract crossing for the neck muscles. Although somatosensory evoked potentials showed uncrossed somatosensory fibres subserving proprioception and light touch, right median nerve somatosensory evoked potential in one patient indicated a partial lemniscal crossing. Sympathetic skin response and blink reflex showed a midline crossing of the spinothalamic and quintothalamic tracts. Brain stem auditory evoked potentials indicated a lack of crossing in the level of the trapezoid body. CONCLUSIONS: Our patients with the ROBO3 E319Kappa mutation show normal perceptual and cognitive functions and have both crossed and uncrossed motor, sensory and auditory pathways.

Cognition↗

PubMed2006

A population-based study of depressive symptoms in multiple sclerosis in Stockholm county: association with functioning and sense of coherence.

OBJECTIVES: To explore and analyse the prevalence of depressive symptoms in people with multiple sclerosis (PwMS), taking into account disease-related and sociodemographic factors, and also to analyse the association between depressive symptoms and functioning (tested and self-reported) and sense of coherence (SOC), respectively. METHODS: Home visits were made to a population-based sample of 166 PwMS. Data were obtained from structured, face-to-face interviews using the Beck Depression Inventory (BDI), the Sickness Impact Profile (SIP) and the SOC scale. A range of tests were also carried out for analyses of different aspects of functioning such as cognitive function, walking capacity and manual dexterity, and structured interviews examined activities of daily living and frequency of social/lifestyle activities. RESULTS: 19% (28/149) of the people were depressed (BDI > or = 13). Depressive symptoms were associated with worse self-reported functioning on the SIP and with poor memory function, but not with any of the other tests of functioning. Depressive symptoms were associated with weak SOC, but not with any of the disease-related or sociodemographic factors studied. CONCLUSION: The prevalence of depressive symptoms in a population-based sample of PwMS is high. Given the serious nature of depression and its association with worse self-reported functioning and weak SOC, attention to, and treatment of, mental-health problems and depression are strongly indicated in the clinical management of multiple sclerosis.

Activities of Daily Living↗

PubMed1980

The use of choline chloride in ataxic disorders.

Fourteen patients with a variety of ataxic disorders were given choline chloride, double blind for six weeks, in an attempt to improve gait and manual dexterity. One patient withdrew before receiving the active drug, twelve patients showed no functional improvement, but one achieved greater mobility; his response, which was dose dependent, ceased when choline was stopped and was reproducible.

Adult↗

PubMed1994

Limb temperature and human tremors.

The changes in postural tremor of the hand produced by moderate cooling of the muscles of one forearm have been investigated in 16 normal subjects and in 16 patients with essential tremor. In both groups, cooling produced a profound long lasting decrease in tremor level of the ipsilateral hand. In normal subjects, although cooling reduced the tremor size, the EMG of the active muscle clearly increased. Warming the limb in normal subjects produced an increase in tremor level and decrease in EMG. Cooling or warming the limb did not, however, significantly change the peak frequency which was quite stable for each subject. The results of cooling were compared with a brief period of ischaemia, which also reduces tremor size. Local cooling may be a useful manoeuvre for patients with essential tremor, and for others who wish to reduce their tremor temporarily in order to improve dexterity.

Adult↗

PubMed1997

Median nerve injury: an underrecognised complication of brachial artery cardiac catheterisation?

OBJECTIVE: To describe the local neurological complications associated with cardiac catheterisation via the right brachial artery. METHODS: A follow up study to determine the mechanism of injury and outcome of patients who sustained a high median nerve palsy after this procedure. Five right handed patients were identified in a 24 month period. Each was assessed clinically and electrophysiologically at presentation. All were followed up initially (range six to 22 months) clinically, electrophysiologically, and using components from the Chessington occupational therapy neurological assessment battery (COTNAB) functional hand assessment. RESULTS: The incidence of this complication was between 0.2 and 1.4%. Three mechanisms of injury were identified. These included direct nerve compression due to formation of antecubital fossa haematoma, direct nerve trauma, and ischaemia secondary to brachial artery occlusion. The initial neurological and nerve conduction deficits improved with time. However, all cases had persistent disability in hand function as documented clinically and on the dexterity and stereognosis subcomponent of the COTNAB test. CONCLUSION: This is an uncommon, but probably underrecognised complication. Those performing cardiac catheterisation via the right brachial artery should be aware of the potential risks of damage to the median nerve. They should evaluate hand function after the procedure and take prompt action if median nerve dysfunction is noted. Damage to the median nerve results in appreciable long term disability, which may have medicolegal relevance.

Aged↗

PubMed2000

Evaluation of three different ways of assessing tremor in multiple sclerosis.

OBJECTIVES: To examine the comparative reliability and validity of three simple ways of rating upper limb tremor in patients with multiple sclerosis. METHODS: Three examiners independently rated severity of upper limb tremor in patients with multiple sclerosis on a 0-10 scale by studying videotape recordings of patients' examinations, spiral drawings, and handwriting samples. The correlations of the tremor severity scores with scores from arm dexterity tests and a tremor related disability scale were also assessed. RESULTS: Rating tremor on posture had a good intrarater and interrater reliability. However, these reliabilities decreased when kinetic tremor was assessed, in part because dysmetria was a confounding factor. The intrarater reliabilities of rating tremor from spirals and handwriting were also good but the interrater reliabilities were only fair to moderate. Tremor severity scored by all three methods correlated highly with scores obtained from the nine hole peg test, finger tapping test, and a tremor related activities of daily living (ADL) questionnaire, indicating that all three methods were valid ways of assessing tremor in multiple sclerosis. CONCLUSION: Multiple sclerosis tremors in posture can be scored using a clinical rating scale in a valid and reliable way, and from spirals and handwriting samples if the ratings are carried out by the same examiner. However, scoring kinetic tremor was less reliable. In addition, the nine hole peg and finger tapping tests provide useful objective assessments of upper limb function in tremulous patients with multiple sclerosis.

Activities of Daily Living↗

PubMed2002

Long term effects of intensity of upper and lower limb training after stroke: a randomised trial.

OBJECTIVE: To assess long term effects at 1 year after stroke in patients who participated in an upper and lower limb intensity training programme in the acute and subacute rehabilitation phases. DESIGN: A three group randomised controlled trial with repeated measures was used. METHOD: One hundred and one patients with a primary middle cerebral artery stroke were randomly allocated to one of three groups for a 20 week rehabilitation programme with an emphasis on (1) upper limb function, (2) lower limb function or (3) immobilisation with an inflatable pressure splint (control group). Follow up assessments within and between groups were compared at 6, 9, and 12 months after stroke. RESULTS: No statistically significant effects were found for treatment assignment from 6 months onwards. At a group level, the significant differences in efficacy demonstrated at 20 weeks after stroke in favour of the lower limb remained. However, no significant differences in functional recovery between groups were found for Barthel index (BI), functional ambulation categories (FAC),action research arm test (ARAT), comfortable and maximal walking speed, Nottingham health profile part 1(NHP-part 1), sickness impact profile-68 (SIP-68), and Frenchay activities index (FAI) from 6 months onwards. At an individual subject level a substantial number of patients showed improvement or deterioration in upper limb function (n=8 and 5, respectively) and lower limb function (n=19 and 9, respectively). Activities of daily living (ADL) scores showed that five patients deteriorated and four improved beyond the error threshold from 6 months onwards. In particular, patients with some but incomplete functional recovery at 6 months are likely to continue to improve or regress from 6 months onwards. CONCLUSIONS: On average patients maintained their functional gains for up to 1 year after stroke after receiving a 20 week upper or lower limb function training programme. However, a significant number of patients with incomplete recovery showed improvements or deterioration in dexterity, walking ability, and ADL beyond the error threshold.

Activities of Daily Living↗

PubMed1989

Acute neurobehavioural effects of toluene.

An acute inhalation chamber study of 42 college students was performed to investigate the relation between exposure to 0, 75, and 150 ppm of toluene and changes in central nervous system function and symptoms. Paid subjects were exposed for seven hours over three days. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory); perception (pattern recognition); psychomotor skill (simple reaction time, continuous performance, digit symbol, hand-eye coordination, finger tapping, and critical tracking); manual dexterity (one hole); mood (profile of mood scales (POMS]; fatigue (fatigue checklist); and verbal ability were evaluated at 0800, 1200, and 1600 hours. Voluntary symptoms and observations of sleep were collected daily. An analysis of variance and test for trend was performed on the difference and score for each concentration reflecting an eight hour workday where each subject was their own control. A 3 x 3 Latin square study design evaluated toluene effects simultaneously, controlling for learning across the three days and the solvent order. Intersubject variation in solvent uptake was monitored in breath and urine. A 5-10% decrement in performance was considered significant if it was consistent with a linear trend at p less than 0.05. Adverse performance at 150 ppm toluene was found at 6.0% for digit span, 12.1% for pattern recognition (latency), 5.0% for pattern memory (number correct), 6.5% for one hole, and 3.0% for critical tracking. The number of headaches and eye irritation also increased in a dose response manner. The greatest effect was found for an increasing number of observations of sleep. Overall, no clear pattern of neurobehavioural effects was found consistent with the type 1 central nervous system as classified by the World Health Organisation. Subtle acute effects, however, were found just below and above the ACGIH TLV of 100 ppm toluene, supporting the position that the guideline be lowered since the biological threshold of behavioural effects may be comparable with the TLV.

Adolescent↗

PubMed1990

Chronic neurobehavioural effects of toluene.

Neurobehavioural tests were undertaken by 30 female workers exposed to toluene and matched controls with low occupational exposure to toluene. The environmental air levels (TWA) of toluene was 88 ppm for the exposed workers and 13 ppm for the controls. The toluene in blood concentrations for the exposed workers was 1.25 mg/l and for the controls 0.16 mg/l. Statistically significant differences between workers exposed to toluene and controls in neurobehavioural tests measuring manual dexterity (grooved peg board), visual scanning (trail making, visual reproduction, Benton visual retention, and digit symbol), and verbal memory (digit span) were observed. Further, the performance at each of these tests was related to time weighted average exposure concentrations of air toluene. The workers exposed to toluene had no clinical symptoms or signs. The question arises as to whether these impairments in neurobehavioural tests are reversible or whether they could be a forerunner of more severe damage.

Adult↗

PubMed1991

Acute behavioural comparisons of toluene and ethanol in human subjects.

A comparison of toluene and ethanol (EtOH) induced changes in central nervous system (CNS) function and symptoms were evaluated in two studies, and when possible the effects of toluene were expressed in EtOH equivalent units. The toluene concentrations were 0, 75, and 150 ppm, bracketing the American Conference of Governmental Industrial Hygienists threshold limit value (ACGIH TLV) of 100 ppm. The socially relevant EtOH doses were 0.00, 0.33, and 0.66 g EtOH/kg body weight, equivalent to two and four 3.5% 12 ounce beers. Forty two paid college students were used in each study. In the first study, subjects were exposed to toluene and an odour masking agent menthol (0.078 ppm) for seven hours over three days. In the second study EtOH or a placebo was administered at 1530 across three days also in the presence of menthol. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory), perception (pattern recognition), psychomotor skill (simple reaction time, continuous performance, symbol-digit, hand-eye coordination, finger tapping, and critical tracking), manual dexterity (one hole), mood (profile on mood scales (POMS), fatigue (fatigue checklist), and verbal ability were evaluated at 0800, 1200, and 1600. Voluntary symptoms and observations of sleep were collected daily. A 3 x 3 latin square design evaluated solvent effects simultaneously controlling for learning and dose sequence. An analysis of variance and test for trend were performed on am-pm differences reflecting an eight hour workday and on pm scores for each solvent, in which subjects were their own control Intersubject variation in absorbance was monitored in breath. A 5 to 10% decrement was considered meaningful if consistent with a linear trend at p less than 0.05. At 150 ppm toluene, losses in performance were 6.0% for digit span, 12.1% for pattern recognition (latency), 5% for pattern memory (number correct), 6.5% for one hole, and 3% for critical tracking. The number of headaches and eye irritation also increased in a dose-response manner. The greatest effect was found for an increasing number of observations of sleep. A range of 2 to 7% decrements suggest the ACGIH TLV of 100 ppm toluene may be a good estimate of the biological threshold supporting a re-evaluation of the TLV. At 0.66 g EtOH/kg body weight symptoms and performance decrements were 6.6% for digit span, 9.2% for pattern recognition, 4.0% for continuous performance, 7.9% for symbol-digit, 16.5% for finger tapping, 6.2% for critical tracking, and 5.2% for the one hole test. The EtOH equivalents at 150 ppm toluene for digit span (0.56g EtOH/kg/body weight), the latency for pattern recognition (0.66 g EtOH kg body weight), and the one hole element "move" (0.37 g EtOH kg body weight) show that the first two measures would be affected at or above the 50 mg% blood alcohol concentration. This concentration is recognised as the lowest alcohol concentration associated with increased numbers of automobile accidents. The results suggest that EtOH may be a useful acute standard to compare the effects of various industrial solvents and support investigating an association between exposure to solvents and increased risk to safety in industry.

Adolescent↗

PubMed1994

Sensorineural objective tests in the assessment of hand-arm vibration syndrome.

Assessment (staging) of workers exposed to vibration, based solely on a subjective history, has been shown to be unsatisfactory. The internationally agreed use of a sensorineural component in the Stockholm classification requires the use of sensory objective tests. Four hundred and twenty two subjects were assessed by a subjective history supplemented by multiple objective tests. These tests covered the vascular, sensorineural, musculoskeletal and dexterity aspects of hand-arm vibration syndrome. Tests to help with the differential diagnosis were also performed. Sensorineural tests are reported as are the associations between the subject's final Stockholm sensorineural staging and the subject's aesthesiometry, temperature threshold results, and grip strength. Scoring systems for these tests were evolved. Data showed that multiple sensory tests increased the accuracy of staging. Aesthesiometry, the temperature neutral zone tests, and grip strength were appropriate for the assessment of the sensory component, especially in separating sensorineural stages 0 and 1 from sensorineural stages 2 and 3. This is an important separation for an occupational physician monitoring subjects exposed to vibration. Analyses of the sensory tests clearly indicated that they need to be done on all digits. In this survey the sensorineural damage was greatest in the forefinger (second) and the little (fifth) fingers. No association was found between smoking and the final staging, aesthesiometry, temperature neutral zone thresholds, or grip strength.

Adult↗

PubMed1998

Occupational exposure to lead and neuropsychological dysfunction.

OBJECTIVE: To evaluate the neuropsychological effects of current low level and previous higher levels of exposure to lead and evaluate the relation between effects of lead and bone lead. METHODS: A neuropsychological test battery was given to 54 storage battery workers with well documented long term exposure to lead. The effect was studied in two subgroups: those whose blood lead had never exceeded 2.4 mmol/l (the low BPbmax group, n = 26), and those with higher exposure about 10 years earlier (the high BPbmax group, n = 28). In both groups, the recent exposure had been low. Correlations between the test scores and the indices of both long term and recent exposure--including the content of lead in the tibial and calcaneal bone--and covariance analyses were used to assess the exposure-effect relation. Age, sex, and education were controlled in these analyses. RESULTS: Analyses within the low BPbmax group showed a decrement in visuospatial and visuomotor function (block design, memory for design, Santa Ana dexterity), attention (digit symbol, digit span), and verbal comprehension (similarities) associated with exposure to lead and also an increased reporting of subjective symptoms. The performance of the high BPbmax group was worse than that of the low BPbmax group for digit symbol, memory for design, and embedded figures, but there was no reporting of symptoms related to exposure, probably due to selection in this group. No relation was found between the output variables and the tibial lead concentration. The calcaneal lead concentrations were related to the symptoms in the low BPbmax group. CONCLUSIONS: Neuropsychological decrements found in subjects with high past and low present exposure indicate that blood lead concentrations rising to 2.5-4.9 mmol/l cause a risk of long lasting or even permanent impairment of central nervous system function. Milder and narrower effects are associated with lower exposures; their reversibility and time course remain to be investigated. History of blood lead gives a more accurate prediction of the neuropsychological effects of lead than do measurements of bone lead.

Adult↗