Psychometric properties of the HSE Indicator Tool: evidence from Argentina.

BACKGROUND: The Health and Safety Executive's Management Standards Indicator Tool (MSIT) is a 35-item self-report questionnaire that assesses seven psychosocial risk factors associated with work-related stress. Although the instrument has been validated in the UK, Italy, Iran and Malta, no validation studies have been carried out in Latin America. AIMS: To examine the factor structure, validity and reliability of the MSIT among Argentine employees. METHODS: A sample of employees of different organizations from Rafaela and Rosario, Argentina, completed an anonymous questionnaire that included the Argentine MSIT and specific scales to measure job satisfaction, workplace resilience and perceived mental and physical health (12-item Short Form Health Survey). Confirmatory factor analysis was used to determine the factor structure of the Argentine MSIT. RESULTS: A total of 532 employees participated in the study (74% response rate). After testing three measurement models, the final respecified model was composed of 24 items distributed in six factors (demands, control, manager support, peer support, relationships and role clarity), showing satisfactory fit indices. The original MSIT change factor was discarded. Composite reliability ranged from 0.70 to 0.82. Although all dimensions showed adequate discriminant validity, convergent validity for control, role clarity and relationships is a matter of concern (average variance extracted values ≤ 0.50). Criterion-related validity was demonstrated by significant correlations between the MSIT subscales and job satisfaction, workplace resilience and mental and physical health. CONCLUSIONS: The Argentine version of the MSIT presents good psychometric properties for use among employees of the region. Further research is needed to provide more evidence on the convergent validity of the questionnaire.

Patients with advanced Parkinson's disease with and without freezing of gait: a comparative analysis of vascular lesions using brain MRI.

INTRODUCTION: Freezing of gait (FOG) is one of the most disabling and enigmatic symptoms in Parkinson's disease. Vascular lesions, observed in magnetic resonance imaging (MRI) scans, may produce or exacerbate this symptom. PATIENTS AND METHODS: The study includes 22 patients with Parkinson's disease subjects, 12 with freezing of gait and 10 without. All patients underwent an MRI scan and any vascular lesions were analysed using the modified Fazekas scale. RESULTS: Patients with FOG scored higher on the modified Fazekas scale than the rest of the group. Although the two groups contained the same percentage of patients with vascular lesions (50% in both groups), lesion load was higher in the group of patients with FOG. Vascular lesions in the periventricular area and deep white matter seem to be the most involved in the development of FOG. DISCUSSION: Vascular lesions may contribute to the onset or worsening of FOG in patients with PD. This study suggests that cerebral vascular disease should be considered in patients with FOG.

[Neuroprotection in Parkinson's disease: analysis though group of experts' methodology]. / Neuroprotección en la enfermedad de Parkinson: análisis a través de la metodología de informadores clave.

INTRODUCTION: Currently used antiparkinsonian drugs neither stop nor slow-down the progressive nature of the disease. The final phase of PD is characterized by the presence of symptoms and signs resistant to dopaminergic agents, such as depression, dementia, freezing and falls. Therefore, it is urgent to develop therapies able to positively modify this outcome. Despite neuroprotection is a research priority in PD, no effective strategies have been found so far. METHOD: A key informants study was conducted. A group of experts in PD fulfilled a questionnaire of 10 questions to explore the most important topics related to neuroprotection. Afterwards a consensus about the current situation of neuroprotection in PD was established and future directions of development were suggested. RESULTS: Most of the answers emphasized the need of new concepts, the limitations of animal models and the difficulties in the difficulties in demonstrating a neuroprotective effects in humans owing to a lack of biomarkers. Some of the experts believe that we are already exerting a disease modifying effect. CONCLUSIONS: The concept of neuroprotection should be widened. Animal models should be improved. A reliable biomarker to start neuroprotective therapies long before the appearance of motor symptoms and to evaluate the neuroprotective effect of any therapy should be urgently developed.

Subacute hemicorporal parkinsonism in 5 patients with infarcts of the basal ganglia.

In 1929, Critchley introduced the term "vascular parkinsonism" (VP), which has been the subject of considerable controversy in neurology. Parkinsonism does not appear to be a frequent consequence of striatal infarcts, although unilateral parkinsonism has been reported as an acute or subacute onset syndrome following strategic infarcts in the striatum. Previous 123-I ioflupane SPECT (DaTSCAN) studies involving radioisotope labeling of the dopamine transporter protein at presynaptic level in patients with IPD (idiopathic Parkinson's disease) have found this technique to be highly sensitive in exploring the nigrostriatal pathway. Previous studies of VP with DatSCAN have been inconclusive. The present study correlates clinical data (unilateral parkinsonism following contralateral lenticular infarction), and radiological (CT/MRI) and functional neuroimaging findings (DatSCAN) in 5 patients with CT/MRI criteria for striatal infarcts. Finally, in 2 of these patients a diagnosis of IPD was made because of the follow-up of clinical signs and pathological DaTSCAN findings not concordant with the size and location of the vascular lesion.

[Study of presynaptic nigrostriatal pathway by 123-I-FD-CIT-SPECT (DatSCAN SPECT) in primary orthostatic tremor]. / Estudio de la vía nigroestriada presináptica mediante 123-I-FP-CIT-SPECT (DatSCAN SPECT) en el temblor ortostático primario.

INTRODUCTION: Primary orthostatic tremor (OT) is defined as a clinical syndrome with high frequency (13-18 Hz) tremor when standing predominantly involving legs and trunk. OT is thought to be driven by an unique supraspinal tremor generator. Previous studies suggest that the nigrostriatal dopaminergic transmission is impaired in patients with OT. CLINICAL CASE: All three patients at an age of 56, 45 and 72 years fulfilled the diagnosis criteria of primary OT. The duration of illness amounted to 4, 3 and 1 year, respectively. The three patients had single-photon emission computed tomography (SPECT) using 123-I-FP-CIT as dopamine transporter tracer (DatSCAN). RESULTS: DatSCAN was normal in every patient. CONCLUSIONS: OT is considered to be caused by a central oscillator because high-frequency tremor bursts are time locked in arm, leg, trunk, and even facial muscles and peripheral stimulation does not reset the tremor. Some reports suggest that the central generator may be located in the posterior fossa. In our patients presynaptic nigrostriatal pathway was normal.

[SPECT with 123I-IBZM: utility in differential diagnosis of degenerative Parkinsonisms and establishment of quantification method]. / SPECT con 123I-IBZM: utilidad en el diagnóstico diferencial de Parkinsonismos degenerativos y establecimiento de un método de cuantificación.

OBJECTIVES: To assess utility of SPECT with 123I-Iolopride ( 123I-IBZM) in the differential diagnosis of patients with Parkinsonian symptoms and try to establish an adequate quantification method. MATERIAL AND METHOD: We analyzed a total of 34 patients who underwent a study with 123I-IBZM SPECT. Studies were analyzed qualitatively (visually) and quantitatively, using different quantification methods. We used different sums of slices (2, 3, 4, and 7 slices) with different cortical regions as a reference (frontal and occipital regions). Results were analyzed statistically. The final diagnosis of patients was established by two neurologists, specialized in movement disorders. RESULTS: Studies were visually assessed as normal in 24 cases and as pathologic in the other 10 cases. Scintigraphic studies had an adequate diagnostic correlation in 33 of the 34 patients. Four of the 8 methods used in the quantification were statistically significant in the differentation between normal and pathological. The use of different cortical brain regions as reference did not improve differentation between normal and pathologic studies. Global quantitative assessment of the studies showed that normal studies had higher values than pathological ones, with important overlapping between both categories. CONCLUSIONS: 123I-IBZM SPECT is an effective diagnostic tool in the establishment of the differential diagnosis in patients with Parkinson's disease and Parkinson-Plus. Quantification of these studies had limited utility since the overlapping of index values between normal and pathological restricts their use in individual cases.

[Optimization of use of levodopa in Parkinson's disease: role of levodopa-carbidopa-entacapone combination]. / Optimización del uso de la levodopa en la enfermedad de Parkinson: papel de la combinación levodopacarbidopa- entacapona.

Levodopa remains the mainstay treatment for Parkinson's disease (PD). Chronic treatment is associated with motor complications (MC) that marred the clinical benefit of levodopa. These problems and experimental data in cell cultures indicating a neurotoxic effect of levodopa have led to the idea of delaying the introduction of levodopa treatment for as long as possible. We here review recent data regarding the mechanism of action of levodopa and its application in clinical practice on the light of the marketing of the combination levodopa-carbidopa- entacapone. Accumulated evidence indicates that MC are mainly the consequence of disease severity governing the degree of dopaminergic depletion and the "pulsatile" dopaminergic stimulation provided by levodopa short plasma half-life. There is no in vivo or clinical evidence of a relevant neurotoxic effect of levodopa. In fact, the recent ELLDOPA study may suggest a neuroprotective effect. Entacapone reduces homocysteine plasma levels which could provide a mechanism to reduce cell death in PD. Currently, the combination levodopa-carbidopa-entacapone is particularly indicated for the treatment of "wearing off" fluctuations. Experimental evidence suggests that early treatment with levodopa-carbidopa-entacapone may substantially ameliorate the incidence of MC. Such a clinical study in "de novo" patients is underway. At present, the combination levodopa-carbidopa-entacapone is indicated when levodopa is judged necessary.

[Study of the pre and post-synaptic dopaminergic system by DaTSCAN/IBZM SPECT in the differential diagnosis of parkinsonism in 75 patients]. / Estudio pre y postsináptico de la vía nigroestriada mediante DaTSCAN o IBZM SPECT en el diagnóstico diferencial del parkinsonismo en 75 pacientes.

INTRODUCTION: Essential tremor (ET) may be misdiagnosed as idiopathic Parkinson's disease (PD). In neurodegenerative diseases, structural imaging, such as CT or MRI, is of limited value for differentiating parkinsonian syndromes since structural changes are often only evident by the time the disease is far advanced. Most cases of symptomatic parkinsonism are vascular parkinsonism, but PD may coexist. The differential diagnosis between Alzheimer's disease (AD) and dementia with Lewy bodies (LBD) is often difficult. OBJECTIVE: To define the utility of functional neuroimaging test to establish differential diagnosis between PD and ET, drug induced parkinsonism, multiple system atrophy and vascular parkinsonism, and between AD and LBD, when clinical presentation, evolution or treatment response are atypical. PATIENTS AND METHODS: A group of 75 patients with parkinsonism was examined by clinical assessment and DaTSCAN (123I-FP-CTI, dopamine transporter protein marker) and/or IBZM SPECT (D2 receptor marker). The patients were recruited from our outpatient clinic. RESULTS: Correlation between initial clinical diagnosis and functional imaging studies (DaTSCAN and/or IBZM SPECT) in our patients did not reach that described (more than 90 %) for these techniques in previously published studies. Conclusions. According to sensitivity and sensibility reported in previous imaging studies of the pre and/or postsynaptic dopaminergic system using DaTSCAN and/ or IBZM, SPECT may be a new tool in the diagnosis of parkinsonian patients with difficult clinical diagnosis.

[Fluctuations and dyskinesias as early L-dopa-induced motor complications in severe Parkinsonian's patients]. / Fluctuaciones y disquinesias como complicación precoz de la levodopaterapia en pacientes parkinsonianos graves.

Daily fluctuations of motor performance and dyskinesias in patients with Parkinson's disease (PD) treated with levodopa represent a difficult challenge to our understanding. We report 10 patients diagnosed of severe PD (Hoehn and Yahr: III-IV/V) treated with levodopa (range of dose: 750-900 mg/day) in single drug therapy since their diagnosis (mean time of levodopatherapy: 4.8 2.4 months, range: 3-6 months). All patients developed motor complications within weeks to months after initiating L-dopatherapy. Two patients received an intravenous apomorphine infusion (mean dose: 8.5 mg/day) during a mean time of 7.5 hours, but motor complications persisted during the infusion in spite of continuous dopaminergic stimulus. The degree of nigrostriatal damage (disease severity) seems to be a very important risk factor for the development of treatment-related motor complications.

[Primary orthostatic tremor: slow harmonic component as responsible of inestability]. / Temblor ortostático primario: componente armónico lento como responsable de la inestabilidad.

BACKGROUND: Orthostatic tremor (OT) is clinically defined as a tremor of the lower limbs and trunk on walking. It bears a significant functional impairement. Although the term orthostatic tremor was first used by Heilman in 1984, Pazzaglia et al had previously described some cases in 1970. Despite the fact that the pathophysiology of this entity is not fully known, the presence of a central oscillator is generally accepted as being responsible. A high frecuency tremor, between 13 and 18 Hz, constitutes an almost patognomonic finding, and treatment with clonazepam usually improves the symptoms. PATIENT AND METHOD: We present a patient who described his symptoms as "cramps" in lower limbs and trunk on standing up, which were relieved on walking or resting. RESULT: This clinical presentation together with a neurophysiological recording of the tremor showing an activity of lower frequency (8 Hz) combined with the usual higher frequency (16 Hz) and above all the clear amelioration of symptoms when treated with gabapentin, i.e. resolution of the low frequency tremor without changes in the 16 Hz tremor, were the peculiar features of this case which merits discussion. CONCLUSIONS: The slow component of the orthostatic tremor is crucial in this case. The improvement with gabapentin is explained by the disappearance of this slow c

[Motor impairment, in patients with severe Parkinson's disease, associated with dopaminergic hyperstimulation (entacapone)]. / Bloqueo motor, en pacientes parkinsonianos graves, en relación con sobrestimulación dopaminérgica (entacapone).

OBJECTIVE: [corrected] Entacapone was given to try to improve the motor complications in eight patients with Parkinson's disease (PD) treated chronically with levodopa, with daily severe motor fluctuations and dyskinesias. PATIENTS AND METHODS: We introduced entacapone (200 mg added to every dose of levodopa) to 8 parkinsonian patients (mean age: 68.25 +/- 2.3; range: 68-72; mean PD duration: 10.4 +/- 2.7 years) treated with oral levodopa, plus a dopa-decarboxylase inhibitor (mean dose: 706.25 +/- 2.3 mg/day; mean period of levodopa-treatment; 9 +/- 2.3 years). Dyskinesias were present in all patients (chorea: 8 patients; "off"--dystonia: 4; byphasic dyskinesias: 3). The type and duration (time "on" and "off") of fluctuations was categorized on the "on-off" charts drawn up by the patients or their relatives, and observation by the investigators after the introduction of entacapone. One patient, with severe impairment with entacapone, was evaluated (motor response) during i.v. apomorphine infusion (40 mg, during 3 hours). RESULTS: The combination of levodopa and entacapone was associated with a net increase in "off" time in all patients (from 5.8 +/- 1.2 h to 12.4 +/- 4.4 h) without change in the URPD. In the patient studied with i.v. apomorphine, "off" periods appeared during the infusion. CONCLUSION: These findings suggest that increased daily levodopa consumption may reduce striatal responsiveness to dopaminergic stimulation in severe parkinsonian patients. These data should be considered when planning the treatment strategy of complex parkinsonian patients.

[Falling backward: atypical sign of iodiopathic Parkison's disease. Use of intravenous apomorphine as a diagnostic test]. / Caídas hacia atrás: signo atípico para la enfermedad de Parkinson idiopática. Utilidad de la apomorfina intravenosa como test diagnóstico.

INTRODUCTION: The differential diagnosis of a parkinsonian syndrome is extensive and complex. In most cases, however, a detailed clinical examination will help to differentiate between idiopathic Parkinson's disease (IPD) and other causes of parkinsonism. PATIENTS AND METHODS: 10 patients with an average age of 65.1 years (range 60-70), of whom 6 were men and 4 women were referred to our department with a diagnosis of IPD and history of backwards falls. The average duration of disease was 4.7 years (range 4-7). All 10 patients had at presentation a severe akinetic-rigid syndrome with no other symptoms of IPD. I.v. apomorphine (APO) was administered to each of them at a rate of 8.9 mg/hr (range 15.3 mg/hr) for an average time of 5.4 hours (range: 3-10 hours). RESULTS: The improvement of the akinetic-rigid state in six of the patients during the i.v. infusion with APO helped to elicit signs that are atypical of IPD (ataxia and postural instability). Three of the patients did not respond to i.v. APO and one of them could not be evaluated, as he did not tolerate the infusion. Oral Dopa challenge or s/c APO bolus has not been as successful in helping to differentiate IPD from other parkinsonian syndromes. CONCLUSIONS: The prompt detection of postural instability or retropopulsion is necessary in order to diagnose atypical parkinsonian syndromes. In difficult cases, continuous i.v. APO will improve the akinetic-rigid state and facilitate the detection of atypical signs. The pharmacokinetic characteristics of APO, and the advantage of it being possible to administer the drug i.v. in a few hours increases the viability of this test.

Pituitary apoplexy: a transient benign presentation mimicking mild subarachnoid hemorrhage with negative angiography.

We report on a patient who presented with isolated transient headache as the only manifestation of pituitary apoplexy. A high index of suspicion and MRI led to the diagnosis. Copyright 1998 Lippincott Williams & Wilkins

Delayed-onset dystonia in patients with antecedents of perinatal asphyxia.

We report 27 cases of delayed-onset dystonia in patients with antecendents of perinatal asphyxia after excluding other possible causes of dystonia. The patients were 16 males and 11 females (mean +/- SD age at onset of dystonia = 13.0 +/- 9.4 yr). Adverse obstetric and/or perinatal events were presented by 20 patients, and other neurological symptoms or signs were present prior to dystonia in 15 patients. The pattern of dystonia was: generalized (eight cases), segmental (six), multifocal (three), hemidystonia (two), and focal (eight). Cranial CT or MRI were normal in 21 cases, and showed brain hemiatrophy in three cases, and periventricular demyelination, subcortical atrophy and increased ventricular size in one case each. The possible cause-effect relationship is discussed.