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.

Pacientes con enfermedad de Parkinson avanzada con y sin congelación de la marcha. Análisis comparativo de lesiones vasculares en resonancia magnética cerebral / Patients with advanced Parkinson’s disease with and without freezing of gait: A comparative analysis of vascular lesions using brain MRI

Introducción: La congelación de la marcha (CDM) es uno de los fenómenos más incapacitantes y menos comprendido de la enfermedad de Parkinson idiopática (EPI). Las lesiones vasculares, objetivadas mediante resonancia magnética nuclear (RMN), podrían contribuir a la aparición o empeoramiento de este síntoma. Pacientes y método: Se estudió un grupo de 22 pacientes con EPI avanzada, 12 con episodios de CDM y 10 sin dichos episodios. Se realizó RMN en todos los pacientes y se analizaron, mediante la escala de Fazekas modificada, las lesiones vasculares existentes. Resultados: Los pacientes con CDM obtuvieron puntuaciones superiores en la escala de Fazekas modificada. Aunque el porcentaje de pacientes que presentaban lesiones vasculares fue el mismo en ambos grupos (50% en los 2 grupos), la carga lesional fue superior en el grupo de pacientes con CDM. Las lesiones vasculares en la región periventricular y en la sustancia blanca profunda son las que parecen estar más implicadas en la aparición de la CDM. Conclusiones: Las lesiones vasculares podrían contribuir a la aparición o al empeoramiento de la CDM en los pacientes con EPI, con este estudio se sugiere que la afección vascular cerebral debe ser considerada en los pacientes con CDM

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

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.

Neuroprotección en la enfermedad de Parkinson: análisis a través de la metodología de informadores clave / Neuroprotection in Parkinson’s disease: analysis though group of expert’s methodology

Introducción. La terapia convencional basada en fármacos dopaminérgicosno frena ni ralentiza de modo significativo el cursoprogresivo de la enfermedad de Parkinson (EP). La fase final de la EPse caracteriza por la presencia de síntomas y signos resistentes a laterapia dopaminérgica (depresión, demencia, disartria, caídas, etc.).Es urgente desarrollar terapias que eviten llegar a estas fases deteniendoo retardando la progresión de la enfermedad. Sin embargo,no se dispone de estrategias neuroprotectoras efectivas.Método. Se realizó un estudio de informadores clave en el queexpertos en EP que cumplimentaron un cuestionario de 10 preguntassobre la problemática más importante en el área de la neuroprotecciónen la EP. Tras ello se estableció un consenso sobre la situaciónactual y se sugirieron nuevas direcciones de investigación.Resultados. La mayoría de respuestas coincidieron en la necesidadde nuevos conceptos, en las limitaciones de los actuales modelosanimales o las dificultades de demostrar un efecto protector en humanospor la falta de biomarcadores. Algunos participantes opinanque ya se está ejerciendo un cierto efecto modificador del curso dela enfermedad.Conclusiones. El concepto de neuroprotección debe ser ampliado,los modelos animales deben mejorarse y urge encontrar un biomarcadorfiable para planificar la terapia en fases más precoces ypara determinar el efecto neuroprotector (AU)

Introduction. Currently used antiparkinsonian drugs neitherstop nor slow-down the progressive nature of the disease. The finalphase of PD is characterized by the presence of symptomsand 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 neuroprotectionis a research priority in PD, no effective strategieshave been found so far.Method. A key informants study was conducted. A group ofexperts in PD fulfilled a questionnaire of 10 questions to explorethe most important topics related to neuroprotection. Afterwardsa consensus about the cur-rent situation of neuroprotection inPD was established and future directions of development weresuggested.Results. Most of the answers emphasized the need of newconcepts, the limitations of animal models and the difficulties inthe difficulties in demonstrating a neuroprotective effects in humansowing to a lack of biomarkers. Some of the experts believethat we are already exerting a disease modifying effect.Conclusions. The concept of neuroprotection should be widened.Animal models should be improved. A reliable biomarkerto start neuroprotective therapies long before the appearance ofmotor symptoms and to evaluate the neuroprotective effect ofany therapy should be urgently developed (AU)

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.

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

Introducción. El temblor ortostático primario (TOP) es una entidad clínica caracterizada por temblor en las extremidades inferiores y tronco, a una frecuencia entre 13-18 Hz, que aparece durante la bipedestación. Parece clara la participación de un oscilador a nivel central. Recientemente se ha apuntado el compromiso de la vía dopaminérgica nigroestriada como parte de la fisiopatología del TOP. Caso clínico. Los tres pacientes estudiados, con una edad de 56, 45 Y 72 años, cumplían criterios clínicos de TOP. El tiempo de evolución de los síntomas era de 4, 3 Y 1 año, respectivamente. A todos los pacientes se les realizó un 123-I-FP-CIT -SPECT (DatSCAN SPECT) marcando, por tanto, la proteína transportadora de dopamina a nivel presináptico para investigar el sistema dopaminérgico a ese nivel. Resultados. El estudio fue normal en todos los casos. Discusión. El TOP se considera debido a un oscilador central al descargar de forma síncrona los músculos de extremidades superiores, inferiores, tronco e incluso músculos faciales y no modificarse el temblor con estímulos periféricoso Diversos estudios sugieren la localización de este oscilador central a nivel de fosa posterior. En nuestros pacientes el estudio de la vía nigroestriada presináptica fue normal

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.

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

Objetivos: Valorar la utilidad de la SPECT con 123I-Iolopride ( 123I-IBZM) en el diagnóstico diferencial de pacientes con síntomas parkinsonianos e intentar establecer un método adecuado de cuantificación. Material y método: Hemos analizado un total de 34 pacientes a los que se les realizó un estudio de SPECT con 123I-IBZM. Los estudios fueron valorados de manera cualitativa (visual), y de manera semicuantitativa, utilizando diferentes métodos de cuantificación. Se emplearon diferentes sumas de cortes (2, 3, 4 y 7 cortes) así como diferentes regiones corticales (frontal y occipital) como referencia. Los resultados fueron analizados estadísticamente. El diagnóstico final de los pacientes fue establecido por dos neurólogos especialistas en trastornos del movimiento. Resultados: En 24 casos el estudio fue valorado visualmente como dentro de la normalidad, y patológico en los 10 casos restantes. Los estudios gammagráficos mostraron una adecuada correlación con el diagnóstico clínico final en 33 de los 34 pacientes. 4 de los 8 métodos utilizados en la cuantificación fueron estadísticamente significativos para diferenciar índices de normalidad respecto a patológicos. El uso de diferentes regiones corticales cerebrales de referencia no mejoró la diferenciación entre estudios normales y patológicos. La valoración cuantitativa global de los estudios mostró que los normales presentaban valores superiores a los patológicos, aunque con importante solapamiento entre ambas categorías. Conclusión: La SPECT con 123I­IBZM es una herramienta diagnóstica eficaz en el establecimiento del diagnóstico diferencial de pacientes con enfermedad de Parkinson (EP) y Parkinson-Plus. La cuantificación de estos estudios muestra una utilidad limitada, ya que el solapamiento de valores entre normales y patológicos limita su uso de manera individual

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.

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

La levodopa continúa considerándose el fármaco más útil en el tratamiento de la enfermedad de Parkinson (EP), pero se asocia con la aparición de complicaciones motoras (CM). Estudios experimentales en la rata y el mono indican que el uso de levodopa asociada a benserazida o carbidopa ya entacapona (triple combinación) se asocia con menor incidencia de discinesias. Estudios en pacientes indican que la triple combinación proporciona un estímulo dopaminérgico más estable, acercándose en mayor medida a reponer la estimulación dopaminérgica continua que caracteriza fisiológicamente al sistema nigroestriatal. No existe evidencia de un efecto neurotóxico de la levodopa en la EP. La discrepancia entre los resultados in vitro e in vivo está principalmente relacionada con la ausencia de células de la glía en los cultivos celulares y bajos niveles de ácido ascórbico. La entacapona bloquea la elevación de homocisteína plasmática inducida por levodopa. lo cual podría ser un mecanismo protector de la muerte celular en la EP. La aplicación clínica de levodopa-carbidopa-entacapona está indicada en pacientes con «deterioro de fin de dosis)}. Los estudios experimentales sugieren que la utilización inicial de esta combinación puede reducir la incidencia de CM. Se está llevando a cabo un estudio clínico multicéntrico para analizar esta hipótesis. Provisionalmente se recomienda la asociación levodopa-carbidopa-entacapona cuando se decida añadir levodopa al tratamiento de la EP

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 Me. Such a clinical study in ((de novo)} patients is underway. At present, the combination levodopa-carbidopaentacapone 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.

Neumoencéfalo como complicación tardía de traumatismo craneoencefálico / Pneumoencephaly as a late complication of cranioencephalic trauma

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[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.

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

La fisopatología de las complicaciones motoras en relación con el tratamiento de la enfermedad de Parkinson (EP) sigue siendo motivo de debate. Presentamos un grupo de 10 enfermos con EP grave, estadio III-IV/V de Hoehn y Yahr, que fueron tratados con levodopa (LD) (rango de dosis: 750 y 900 mg/día), en monoterapia, desde el diagnóstico (tiempo medio de levodopaterapia: 4,8 ñ 2,4 meses; rango: 3-6 meses). Todos desarrollaron complicaciones motoras, al cabo de semanas o meses de iniciada la levodopaterapia. Dos de estos enfermos recibieron una infusión intravenosa de apomorfina (dosis media de 8,5 mg/hora), durante un tiempo medio de 7,5 horas, persistiendo las complicaciones motoras durante la infusión, a pesar del estímulo dopaminérgico continuo. El grado de denervación nigroestriada (severidad de la enfermedad) parece ser un factor determinante para el desarrollo de las complicaciones motoras, en relación con el tratamiento. (AU)

[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

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

FUNDAMENTO: El temblor ortostático (TO) se define clínicamente como el temblor que aparece en las extremidades inferiores y el tronco durante la bipedestación y que habitualmente supone una importante incapacidad funcional. Aunque el término fue acuñado en 1984 por Heilman en la bibliografía inglesa como orthostatic tremor, previamente ya habían sido descritos los primeros casos por Pazzaglia et al en 1970. La fisiopatología del problema se sigue discutiendo, aunque se acepta la existencia de un oscilador central. La detección en los estudios neurofisiológicos de un temblor de alta frecuencia, entre 13 y 18 Hz, es casi patognomónica. Habitualmente el tratamiento con clonacepam mejora los síntomas. PACIENTE Y MÉTODO: Presentamos el caso de un paciente con calambres que le agarrotaban las piernas en relación con ortostatismo y cuyos síntomas se aliviaban con la marcha y el reposo. RESULTADOS: El registro neurofisiológico objetivó temblor con un componente armónico a menor frecuencia (8 Hz), coexistiendo con la frecuencia habitual a 16 Hz. El tratamiento con gabapentina mejoró los síntomas al desaparecer este componente lento. CONCLUSIONES: El componente lento del temblor es el factor fundamental que determina la clínica en este caso. La mejoría con gabapentina viene determinada por la desaparición de este componente lento (AU)