The FAB: a Frontal Assessment Battery at bedside

OBJECTIVE

To devise a short bedside cognitive and behavioral battery to assess frontal lobe functions.

METHODS

The designed battery consists of six subtests exploring the following: conceptualization, mental flexibility, motor programming, sensitivity to interference, inhibitory control, and environmental autonomy. It takes approximately 10 minutes to administer. The authors studied 42 normal subjects and 121 patients with various degrees of frontal lobe dysfunction (PD, n = 24; multiple system atrophy, n = 6; corticobasal degeneration, n = 21; progressive supranuclear palsy, n = 47; frontotemporal dementia, n = 23).

RESULTS

The Frontal Assessment Battery scores correlated with the Mattis Dementia Rating Scale scores (rho = 0.82, p < 0.01) and with the number of criteria (rho = 0.77, p < 0.01) and perseverative errors (rho = 0.68, p < 0.01) of the Wisconsin Card Sorting Test. These variables accounted for 79% of the variance in a stepwise multiple regression, whereas age or Mini-Mental State Examination scores had no significant influence. There was good interrater reliability (kappa = 0.87, p < 0.001), internal consistency (Cronbach's coefficient alpha = 0.78), and discriminant validity (89.1% of cases correctly identified in a discriminant analysis of patients and controls).

CONCLUSION

The Frontal Assessment Battery is easy to administer at bedside and is sensitive to frontal lobe dysfunction.

An ecological approach to planning dysfunction: script execution

Planning, which concerns many activities in everyday life, is a two-stage process. The first one predetermines a course of actions aimed at achieving some specific goals. It is founded on managerial knowledge or overlearned sequences of events and may be tested by script generation. The second stage entails monitoring and guiding the execution of the plan to a successful conclusion. It must take into account environmental contingencies and may be tested by script execution. If the frontal lobes intervene not only in managerial knowledge (Grafman, 1989) but also in binding the plan with contextual environment (Damasio, Tranel and Damasio, 1991; Shallice and Burgess, 1991), script execution would be more sensitive than script generation to planning deficits. To test this hypothesis, script execution and script generation were compared in 11 patients with a dysexecutive syndrome and 10 matched controls, using three scripts of daily life activities: (1) 'shopping for groceries'; (2) 'cooking'; (3) 'answering a letter and finding the way to post the reply'. Two way ANOVAs showed more errors in execution than in generation, more errors in patients than in controls, and a greater difference between execution and generation in patients than in controls. Furthermore, 'context neglect' and 'environmental adherence' were the two types of errors that best differentiated patients from controls. Finally, the total number of errors in execution correlated with the score on behavioral questionnaires answered by occupational therapists. These results confirm our hypothesis and suggest that script execution may be a valid ecological approach to estimate the severity of deficits in daily life activities.

[Primary hyperparathyroidism: etiology, diagnosis and treatment]

Primary hyperparathyroidism is a not so infrequent disease that is often overlooked by physicians. Its incidence is estimated to be about 28 in 100.000 subjects, mainly women over seventy years old. Three to four percents of women over seventy are affected. Hyperparathyroidism can be isolated or be a component of a more complex syndrome like multiple endocrine neoplasms (MEN). Patients can be asymptomatic or present with symptoms like asthenia, hypertension or nephrolithiasis. The biological investigation requires the combined measurements of plasmatic ionized calcium and parathormone. In some cases, more specific explorations like calcium loading tests have to be performed in order to confirm the diagnosis.

Human genetic factors related to susceptibility to mild malaria in Gabon

Several human genetic factors, including red blood cell polymorphisms (ABO blood group, sickle-cell trait, G6PD deficiency) as well as point mutations in the mannose binding protein (MBP) and in the promoter regions of both the TNF-alpha and NOS2 genes, influence the severity of disease due to infection with Plasmodium falciparum. We assessed their impact on mild P. falciparum malaria, as part of a longitudinal investigation of clinical, parasitological and immunological parameters in a cohort of 300 Gabonese schoolchildren. We found the following frequencies: blood group O (0.54), sickle-cell trait (0.23), G6PD deficiency (0.09), MBP gene mutations (0.34), TNF-alpha promoter mutations (at positions -238: 0.17 and -308: 0.22) and NOS2 promoter mutation (0.18). Blood group O or hemoglobin AA were associated with protection against higher parasitemia. Girls with normal G6PD enzyme activity were protected against clinical malaria attacks. In addition, we demonstrated for the first time that the mutation at position -238 of the gene coding for the promoter region of TNF-alpha was positively correlated with the level of the antibody response specific for epitopes of the antigens MSA-2 and RAP-1 of P. falciparum.

Fracture and bone mineral density in hemodialysis patients

AIM

The aim of this cross-sectional study was to determine in hemodialysis patients the pattern of low trauma fracture, the ability of dual X-ray absorptiometry (DXA) to discriminate between patients with and without fracture, and the magnitude, distribution and mechanism of bone loss.

PATIENTS AND METHODS

Eighty-eight patients were studied. Bone mineral density (BMD) was measured by DXA at lumbar spine (LS), femoral neck (FN) and 3 radius sites (UD, MID and 1/3R). In 11 patients (12.5%), 16 fractures occurred and were predominant at the distal forearm and ribs.

RESULTS

Patients with fracture had a significatively lower BMD Z-score at LS (-1.34 +/- 1.66 vs -0.42 +/- 1.23), at FN (-1.58 +/- 1.25 vs -0.60 +/- 1.01), at MID radius (-2.59 +/- 1.34 vs -0.93 +/- 1.76) and 1/3 radius (-1.62 +/- 1.60 vs -0.39 +/- 1.32). They also had a longer history of dialysis (113 +/- 64 vs 53 +/- 65 months). Prevalence of osteoporosis varied from 23% at LS to 50% at MID radius.

CONCLUSION

Multiple regression analysis showed that there was no influence of gender, age, parathormone status and primary renal disease on BMD. However, at FN, UD, MID and 1/3 radius, a significantly negative correlation was found between length of dialysis and BMD Z-score. By contrast at LS, there was a positive correlation between age at onset of dialysis and BMD Z-score. Despite occurrence of fracture at the fistula forearm, BMD levels were similar in both arms.

Immune response to Plasmodium falciparum liver stage antigen-1: geographical variations within Central Africa and their relationship with protection from clinical malaria

Two populations of schoolchildren from Gabon and Cameroon were tested in 1995 for their immunological reactivity to synthetic peptides (LSA-Rep, LSA-J and LSA-CTL) from Plasmodium falciparum liver stage antigen-1 (LSA-1). The prevalence and levels of both cellular (lymphocyte proliferation, tumour necrosis factor alpha (TNF alpha), interferon gamma (IFN gamma), and interleukin-10 (IL-10)) and humoral (immunoglobulin G) responses were determined. Protection from clinical malaria, determined after a prospective 1 year study in both sites, was associated with elevated proliferative responses to LSA-Rep and LSA-CTL in the Gabonese children, as well as with higher antibody levels to both schizont extract and LSA-Rep. The prevalence of peptide-stimulated TNF-alpha secretion was higher in the Cameroonian group, but higher levels of antibodies to LSA-Rep and LSA-J were found in the Gabonese children. The immunological differences observed between children in the 2 study sites are discussed in the context of both epidemiological and individual host factors.

Development of minimal lentivirus vectors derived from simian immunodeficiency virus (SIVmac251) and their use for gene transfer into human dendritic cells

Lentivirus-derived vectors are very promising gene delivery systems since they are able to transduce nonproliferating differentiated cells, while murine leukemia virus-based vectors can only transduce cycling cells. Here we report the construction and characterization of highly efficient minimal vectors derived from simian immunodeficiency virus (SIVmac251). High-fidelity PCR amplification of DNA fragments was used to generate a minimal SIV vector formed from a 5' cytomegalovirus early promoter, the 5' viral sequences up to the 5' end of gag required for reverse transcription and packaging, the Rev-responsive element, a gene-expressing cassette, and the 3' long terminal repeat (LTR). Production of SIV vector particles was achieved by transfecting 293T cells with the vector DNA and helper constructs coding for the viral genes and the vesicular stomatitis virus glycoprotein G envelope. These SIV vectors were found to have transducing titers reaching 10(7) transducing units/ml on HeLa cells and to deliver a gene without transfer of helper functions to target cells. The central polypurine tract can be included in the minimal vector, resulting in a two- to threefold increase in the transduction titers on dividing or growth-arrested cells. Based on this minimal SIV vector, a sin vector was designed by deleting 151 nucleotides in the 3' LTR U3 region, and this SIV sin vector retained high transduction titers. Furthermore, the minimal SIV vector was efficient at transducing terminally differentiated human CD34(+) cell-derived or monocyte-derived dendritic cells (DCs). Results show that up to 40% of human primary DCs can be transduced by the SIV vectors. This opens a new perspective in the field of immunotherapy.

Mitochondrial mutations of Leber's hereditary optic neuropathy: a risk factor for multiple sclerosis

Multiple sclerosis (MS) and Leber's hereditary optic neuropathy (LHON) have been found to occur in combination. Based on an extensive literature search and on a clinical analysis of 55 LHON pedigrees (103 patients) and 40 patients with definite MS, this study concludes that the association of LHON and MS is more than a coincidence, and that carrying a primary LHON mutation is a risk factor for developing MS. All three primary LHON mutations occurring in the European and North American populations have been found to be associated with an MS-like syndrome. The neurological characteristics of MS associated with LHON are indistinguishable from those of MS in general, but the severe and bilateral visual symptoms and signs justify considering these patients as a clinical subgroup of MS and screening them for LHON mutations. However, screening LHON patients for MS appears to be more rewarding.

In vivo neutrophil recruitment by granulocyte chemotactic protein-2 is assisted by gelatinase B/MMP-9 in the mouse

Granulocyte chemotactic protein-2 (GCP-2) of the mouse is a potent neutrophil chemotactic and activating factor in vitro and in vivo. Gelatinase B/matrix metalloproteinase-9 is released from neutrophils within 1 h after stimulation with GCP-2. In vitro neutrophil chemotaxis by GCP-2 was not impaired by specific inhibitory monoclonal antibodies (mAb) against gelatinase B, indicating that gelatinase B is not involved in chemotaxis of neutrophils through polycarbonate filters. To investigate if gelatinase B degranulation is involved in in vivo cell migration toward GCP-2, experiments were performed with gelatinase B knockout mice. When mouse GCP-2 was injected intradermally in mice, a dose-dependent neutrophil chemotactic response was observed, and this cell migration was significantly impaired in young mice by genetic gelatinase B knockout. In adult vs. young gelatinase B-deficient mice, such compensatory mechanisms as higher basal neutrophil counts and less impairment of chemotaxis toward local GCP-2 injection were observed. These experiments prove the concept that gelatinase B release under pressure of GCP-2 is a relevant, but not exclusive, effector mechanism of neutrophil chemotaxis in vivo and that known mechanisms, other than the release of gelatinase B, allow for a full-blown chemotactic response and compensate for gelatinase B deficiency in adult life in the mouse.

Total hip arthroplasty with use of the Metasul metal-on-metal articulation. Four to seven-year results

BACKGROUND

Total hip replacements with a metal-on-metal articulation were commonly used until the mid-1970s; most were then abandoned in favor of hip replacement with a metal-on-polyethylene articulation. The reason for this change was primarily early cup loosening, which was more prevalent with these metal-on-metal designs than it was with metal-on-polyethylene designs. In the late 1980s, a metal-on-metal design with improved clearance (adequate space between the femoral head and the acetabular articulation surface to allow fluid film lubrication and clearance of any debris from within this joint), metal hardness, and reproducible surfaces was introduced by Sulzer Orthopedics in Switzerland. Orthopaedic surgeons were interested in this Metasul articulation because the contribution of polyethylene wear particles to the failure of total hip replacements had become evident. This study was undertaken to review the clinical performance of this implant and to determine if early acetabular loosening or revision and wear and osteolysis were prevalent.

METHODS

Between 1991 and 1994, seventy patients (seventy hips) had a total hip replacement with the Metasul metal-on-metal articulation and a cemented Weber cup. Nine patients died less than four years after the replacement; none of these deaths were related to the operation. Five patients were not available for radiographic evaluation, but they were contacted and it was known that the hip was not painful and had not been revised. Fifty-six patients (fifty-six hips) had complete clinical and radiographic data four to 6.8 years after the operation, and they made up the study group. The patients were evaluated with use of the Harris hip score, a patient-self-assessment form, and radiographs.

RESULTS

At an average of 5.2 years (range, four to 6.8 years) after the operation, the average total Harris hip score for the fifty-three patients who did not have a revision was 89.6 points (range, 62 to 100 points). The average Harris pain score was 41.0 points (range, 30 to 44 points), and the average Harris limp score was 9.4 points (range, 5 to 11 points). One patient had revision of a loose cup, but there were no other loose acetabular components in the series. Two patients had revision of the acetabular component because of dislocation. No patient had a loose or revised femoral component. Therefore, the mechanical failure rate was one (2 percent) of fifty-six patients. Thirty-six of forty-seven patients who completed the patient-self-assessment form rated their result as excellent; seven, as very good; two, as good; one, as fair; and one, as poor. Wear could not be measured on radiographs because of the metal-on-metal articulation. No hip had radiographic evidence of acetabular osteolysis and two hips had calcar resorption, but there was no other radiographic evidence of focal osteolysis.

CONCLUSIONS

Our four to seven-year experience with this articulation surface indicates that the clinical results are similar to those of total hip replacements with a metal-on-polyethylene articulation. We believe that the Metasul articulation may have a role in reducing the wear that occurs with total hip replacement. The Metasul articulation appears to be particularly indicated for more active patients. A historical comparison with the reports in the literature of which we are aware indicated that the hips in our study had a lower rate of acetabular revision and loosening than did those with previous metal-on-metal designs and that they had no more acetabular loosening or osteolysis than did those with metal-on-polyethylene articulations followed for an average of five years.

Antibody responses to Plasmodium falciparum: evolution according to the severity of a prior clinical episode and association with subsequent reinfection

We measured sporozoite- and total parasite antigen-specific IgG and IgM antibodies before and after treatment in matched groups of Gabonese children who presented with either mild or severe Plasmodium falciparum malaria. We investigated the influence of various parameters on these antibody responses, including clinical presentation, age, and post-treatment reinfection profiles. IgG but not IgM responses were strongly influenced by both clinical and parasitological status. IgG responses to the repeat region of the circumsporozoite protein, which were low at admission, particularly so in those with severe anemia, increased after treatment but showed no association with either age or reinfection profiles. Total parasite antigen-specific IgG responses were strongly influenced by parasitological status, and also differed significantly when segregated according to clinical status at admission, age, and reinfection histories. Most notably, anti-parasite IgG responses measured when children were parasite-free were higher and a good indicator of recent reinfections in those who presented with mild rather than with severe malaria. The profile of responses in the latter group suggests some immune system dysfunction, which may reflect the induction of tolerance to parasite antigens.

[Chronic renal failure: management suggestions based on scientific evidence]

Chronic renal failure whatever its etiology is a progressive disease, associated with important morbidity and mortality. Most patients will require renal replacement therapies (hemodialysis, peritoneal dialysis or transplantation). An early follow up by nephrologists, an optimal control of hypertension and of the glomerular hyperfiltration syndrome, might allow slowing the rate of evolution of nephropathies. At least, this approach allows to delay complications of renal failure and to improve the patient survival. Guidelines based on scientific studies are presently available to approach the treatment of chronic renal failure.

How patients with Parkinson's disease retrieve and manage cognitive event knowledge

Several studies have pointed out that basal ganglia are involved in adaptive control of action at both motor and cognitive level. This study aimed to investigate how basal ganglia retrieve and manage script event knowledge required in planning behavior. Script event knowledge was investigated in patients with Parkinson's Disease using three kinds of activity that differed in familiarity. Unlike patients with prefrontal lesions, patients with Parkinson's Disease were able to order events in a typical sequence and obeyed the boundaries and hierarchies between events. In contrast, patients with Parkinson's Disease were impaired in evaluating how important each script event was within the context of goal-oriented planning activity. Our findings indicate that the prefrontal cortex and the basal ganglia are differentially involved in planning. The role of the basal ganglia might consist in providing a feedback about the goodness of each action while building up meaningful sequences of events during learning.

Diagnosis and management of Alzheimer's disease and other disorders associated with dementia. The role of neurologists in Europe. European Federation of Neurological Societies

In 1998 a task force to develop guidelines for diagnostic evaluation and treatment of dementia was initiated by the European Federation of Neurological Societies (EFNS) scientist panel on dementia. The aims of the task force were to provide evidence-based recommendations and to highlight the role of the neurologist in the management of patients with Alzheimer's disease and other disorders associated with dementia. We based our recommendations on a review of available evidence-based guidelines supplemented with further literature reviews. The recommendations were derived from consensus meetings and relate to individual patient management, as there are inadequate data on the cost-effectiveness of different diagnostic evaluations and treatments for dementia. Their specific applications will depend upon available resources. The particular contributions of the neurologist include: early identification and differential diagnosis of rare and common brain disorders causing cognitive and behavioural symptoms, referral for and interpretation of ancillary investigations, and identification and treatment of vascular and other concurrent diseases. A review of the management of dementia in Europe revealed considerable variation. In some countries neurologists have taken the lead in the management of patients with dementia, while in other countries the neurologist is rarely involved. We recommend that neurologists should have a clear role in the management of dementia in the whole of Europe. They should be involved in the diagnostic evaluation of dementia and facilitate the development of multidisciplinary teams for evaluation and management of patients with cognitive disturbances. The increasing role of neurology in the management of patients with dementia has important implications for training and education.

Similar subcortical pattern of cognitive impairment in AIDS patients with and without dementia

The aim of this study was to develop a series of neuropsychological tests that define the cortical and subcortical features of cognitive impairment and the characteristics of memory in demented and mildly cognitively impaired AIDS patients. We attempted to establish a usable method to assess and determine the type and degree of cognitive impairment in individual AIDS patients. We examined 53 patients without central nervous system opportunistic infections. A short battery included two scales of global efficiency (the Mattis dementia rating scale and the Mini Mental State Examination), a psychomotor speed test, an executive control assessment and explicit memory evaluation. Patients were categorized into four groups based on their score on both the Mattis dementia rating scale and the DSM-IV criteria: (1) asymptomatic; (2) having AIDS without cognitive impairment; (3) having AIDS with mild cognitive impairment; and (4) having AIDS dementia. Patients with mildly impaired cognition demonstrated slowed thinking, abnormal initiation and conceptualization, and memory impairment. AIDS dementia patients had slower motor activity and memory recall was more severely affected. The short neuropsychological battery was able to characterize modified cognitive performances in both severely and mildly cognitively impaired AIDS patients. The subcortical pattern of the memory disorder was obvious, regardless of the degree of cognitive impairment.

The impact of metrifonate therapy on caregivers of patients with Alzheimer's disease: results from the MALT clinical trial. Metrifonate in Alzheimer's Disease Trial

OBJECTIVE

To assess the impact on burden reported by caregivers of patients with mild to moderate Alzheimer's disease (AD) who were treated with metrifonate during a randomized double blind clinical trial.

DESIGN

Randomized clinical trial, with a 2-week screening period and a 26-week double blind, placebo controlled, treatment phase. Caregivers were assessed at baseline, at 12 weeks, and at end of trial.

SETTING

Caregivers were interviewed at clinics as part of the assessment of the patients.

PARTICIPANTS

Six hundred and three caregivers of AD patients who were enrolled in the MALT trial; 591 (98%) provided data suitable for analysis at baseline, and 546 (91%) provided data allowing for inclusion in the analysis of change scores.

MEASUREMENTS

The Caregiver Burden Assessment consisted of the Screen for Caregiver Burden, including both subjective (SCB-subj) and objective (SCB-obj) scores; the cognitive subscale of Poulshock and Deimling (PD); an abridged version of the Relatives Stress Scale (aRSS); assessments of time spent in providing care, including the Caregiver Activity Time Scale (CATS); and demographic and background variables on both the patient and caregiver.

RESULTS

Treatment of mild to moderate AD patients with metrifonate for a duration of 26 weeks significantly reduced the psychological burden of care to the caregivers, as measured by the SCB-subj, the PD, and the aRSS. There were no statistically significant differences on the measures assessing the time spent in caregiving, except for the caregiver's subjective impression of the change in time spent providing care during the trial. When comparing individual dose groups, most of the measures of burden showed the largest benefits in burden for the 60/80 mg group, followed by the 40/50 mg group, and then the placebo group. However, there was no statistically significant dose effect.

CONCLUSIONS

This study provides the first evidence from a randomized clinical trial of any acetylcholinesterase inhibitor used in the treatment of AD demonstrating a positive impact on the patient's caregiver as well as benefits to the patient. These results were shown consistently across several measurement scales and were observed after six months of treatment. These findings reinforce the clinical significance of research that has shown that metrifonate has beneficial impacts on the cognitive, behavioral, and functional abilities of AD patients. Because caregiver burden is a leading factor in the decision for institutional care placement, the ability to favorably impact that burden through pharmacological treatment of the patient is important.

Distinct prefrontal activations in processing sequence at the sentence and script level: an fMRI study

Neuropsychological studies have shown that the prefrontal cortex is important in planning and monitoring everyday behaviour. In this study, using functional magnetic resonance imaging (fMRI), we investigated whether specific prefrontal regions are involved in processing a sequence of actions. Subjects were required to perform two different tasks: Script-event order and Sentence-word order. Script sequence and word sequence processing were found to activate partially overlapping areas which are known to be implicated in language processing. In addition, the Script-task activated a large area in the dorsolateral prefrontal cortex (Brodmann area 6 and 8, BA 6 and 8), in both the left and right hemispheres, as well as the left supplementary motor area and left angular gyrus (BA 39). Our results suggest that these prefrontal areas may be more specifically involved in the process of analysing sequential links in the action domain.

Resistance of young gelatinase B-deficient mice to experimental autoimmune encephalomyelitis and necrotizing tail lesions

Regulated expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) plays a role in various physiological processes. To determine in vivo how unbalanced expression of these factors can promote or affect the course of pathologies, we knocked out the mouse gelatinase B gene by replacing the catalytic and zinc-binding domains with an antisense-oriented neomycin resistance gene. Adult gelatinase B-deficient mice and wild-type controls could be induced to develop experimental autoimmune encephalomyelitis (EAE) with similar scores for neurologic disease, blood-brain barrier permeability, and central nervous system histopathology. However, whereas diseased control animals showed necrotizing tail lesions with hyperplasia of osteocartilaginous tissue, adult gelatinase B-deficient mice were resistant to this tail pathology. Gelatinase B-deficient mice younger than 4 weeks of age were significantly less susceptible to the development of EAE than were age matched controls and, even as they aged, they remained resistant to tail lesions. These data illustrate that gelatinase B expression plays a role in the development of the immune system and that, in ontogenesis, the propensity to develop autoimmunity is altered by the absence of this MMP.