Dyslipidemias and stroke prevention: Recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology.

OBJECTIVE: We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. DEVELOPMENT: We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. CONCLUSIONS: In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value <55 mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value.

Dislipidemias y prevención del ictus: recomendaciones del Grupo de Estudio de Enfermedades Cerebrovasculares de la Sociedad Española de Neurología / Dyslipidemias and stroke prevention: recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology

Objetivo: Actualizar las recomendaciones de la Sociedad Española de Neurología para la prevención del ictus, tanto primaria como secundaria, en pacientes con dislipidemia. Desarrollo: Se ha realizado una revisión sistemática en Pubmed evaluando los principales aspectos relacionados con el manejo de las dislipidemias en la prevención primaria y secundaria del ictus, elaborándose una serie de recomendaciones relacionadas con los mismos. Conclusiones: En prevención primaria se recomienda determinar el riesgo vascular del paciente con el fin de definir los objetivos de LDLc. En prevención secundaria tras un ictus de origen aterotrombótico se recomienda un objetivo de LDLc < 55 mg/dl, mientras que en ictus isquémicos de origen no aterotrombótico, dado que su relación con dislipidemias es incierta, se establecerán los objetivos en función del grupo de riesgo vascular de cada paciente. Tanto en prevención primaria como secundaria las estatinas son los fármacos de primera elección, pudiendo asociarse ezetimiba y/o inhibidores de PCSK9 en aquellos casos que no alcancen los objetivos terapéuticos. (AU)

Objective: We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. Development: We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. Conclusions: In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value < 55 mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value. (AU)

Recommendations of the Spanish Society of Neurology for the prevention of stroke. Interventions on lifestyle and air pollution.

OBJECTIVE: To update the recommendations of the Spanish Society of Neurology regarding lifestyle interventions for stroke prevention. DEVELOPMENT: We reviewed the most recent studies related to lifestyle and stroke risk, including randomised clinical trials, population studies, and meta-analyses. The risk of stroke associated with such lifestyle habits as smoking, alcohol consumption, stress, diet, obesity, and sedentary lifestyles was analysed, and the potential benefits for stroke prevention of modifying these habits were reviewed. We also reviewed stroke risk associated with exposure to air pollution. Based on the results obtained, we drafted recommendations addressing each of the lifestyle habits analysed. CONCLUSIONS: Lifestyle modification constitutes a cornerstone in the primary and secondary prevention of stroke. Abstinence or cessation of smoking, cessation of excessive alcohol consumption, avoidance of exposure to chronic stress, avoidance of overweight or obesity, a Mediterranean diet supplemented with olive oil and nuts, and regular exercise are essential measures in reducing the risk of stroke. We also recommend implementing policies to reduce air pollution.

Stroke prevention in patients with arterial hypertension: Recommendations of the Spanish Society of Neurology's Stroke Study Group.

OBJECTIVE: To update the recommendations of the Spanish Society of Neurology on primary and secondary stroke prevention in patients with arterial hypertension. DEVELOPMENT: We proposed several questions to identify practical issues for the management of blood pressure (BP) in stroke prevention, analysing the objectives of blood pressure control, which drugs are most appropriate in primary prevention, when antihypertensive treatment should be started after a stroke, what levels we should aim to achieve, and which drugs are most appropriate in secondary stroke prevention. We conducted a systematic review of the PubMed database and analysed the main clinical trials to address these questions and establish a series of recommendations. CONCLUSIONS: In primary stroke prevention, antihypertensive treatment should be started in patients with BP levels >  140/90 mmHg, with a target BP of < 130/80 mmHg. In secondary stroke prevention, we recommend starting antihypertensive treatment after the acute phase (first 24 hours), with a target BP of < 130/80 mmHg. The use of angiotensin-II receptor antagonists or diuretics alone or in combination with angiotensin-converting enzyme inhibitors is preferable.

Stroke prevention in patients with type 2 diabetes or prediabetes. Recommendations from the Cerebrovascular Diseases Study Group, Spanish Society of Neurology. / Prevención de ictus en pacientes con diabetes mellitus tipo 2 o prediabetes. Recomendaciones del Grupo de Estudio de Enfermedades Cerebrovasculares de la Sociedad Española de Neurología.

OBJECTIVE: To update the Spanish Society of Neurology's guidelines for stroke prevention in patients with type 2 diabetes or prediabetes, analysing the available evidence on the effect of metabolic control and the potential benefit of antidiabetic drugs with known vascular benefits in addition to conventional antidiabetic treatments in stroke prevention. DEVELOPMENT: PICO-type questions (Patient, Intervention, Comparison, Outcome) were developed to identify practical issues in the management of stroke patients and to establish specific recommendations for each of them. Subsequently, we conducted systematic reviews of the PubMed database and selected those randomised clinical trials evaluating stroke as an independent variable (primary or secondary). Finally, for each of the PICO questions we developed a meta-analysis to support the final recommendations. CONCLUSIONS: While there is no evidence that metabolic control reduces the risk of stroke, some families of antidiabetic drugs with vascular benefits have been shown to reduce these effects when added to conventional treatments, both in the field of primary prevention in patients presenting type 2 diabetes and high vascular risk or established atherosclerosis (GLP-1 agonists) and in secondary stroke prevention in patients with type 2 diabetes or prediabetes (pioglitazone).

Dyslipidemias and stroke prevention: recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology. / Dislipidemias y prevención del ictus: recomendaciones del Grupo de Estudio de Enfermedades Cerebrovasculares de la Sociedad Española de Neurología.

OBJECTIVE: We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. DEVELOPMENT: We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. CONCLUSIONS: In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value <55mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value.

Impact of COVID-19 outbreak in reperfusion therapies of acute ischaemic stroke in northwest Spain.

BACKGROUND AND PURPOSE: Spain has been one of the countries more heavily stricken by SARS-CoV-2, which has had huge implications for stroke care. The aim was to analyse the impact of the COVID-19 epidemic outbreak on reperfusion therapies for acute ischaemic stroke in the northwest of Spain. METHODS: This was a Spanish multicentre retrospective observational study based on data from tertiary hospitals of the NORDICTUS network. All patients receiving reperfusion therapy for ischaemic stroke between 30 December 2019 and 3 May 2020 were recorded, and their baseline, clinical and radiological characteristics, extra- and intra-hospital times of action, Code Stroke activation pathway, COVID-19 status, reperfusion rate, and short-term outcome before and after the setting of the emergency state were analysed. RESULTS: A total of 796 patients received reperfusion therapies for ischaemic stroke. There was a decrease in the number of patients treated per week (46.5 patients per week vs. 39.0 patients per week, P = 0.043) and a delay in out-of-hospital (95.0 vs. 110.0 min, P = 0.001) and door-to-needle times (51.0 vs. 55.0, P = 0.038). Patients receiving endovascular therapy obtained less successful reperfusion rates (92.9% vs. 86.6%, P = 0.016). COVID-19 patients had more in-hospital mortality. CONCLUSION: A decrease in the number of patients benefiting from reperfusion therapies was found, with a delay in out-of-hospital and door-to-needle times and worse reperfusion rates in northwest Spain. COVID-19 patients had more in-hospital mortality.

Stress at work in migraine patients: differences in attack frequency.

INTRODUCTION: Migraine is a common and prevalent disease that contributes to health expenditure and interferes with quality of life. Our goal was to analyse the level of stress at work in a sample of migraine and its possible association with the chronicity of the process MATERIAL AND METHODS: We applied the Maslach Burnout Inventory, consisting of 22 items grouped into blocks that assess emotional exhaustion (EE), personal accomplishment (PA), depersonalisation at work (DP)] and positive influence (PI), to 94 consecutive subjects recruited in the outpatient clinic. Differences were compared between clinical groups (chronic migraine [CM]: > 15 days/month with headache over a 3-month period vs episodic migraine [EM]: < 15 days/month with headache) using the general linear model adjusted for age and MIDAS score RESULTS: The mean age was higher in the CM group. Mean MIDAS scores were 51 ± 4.1 in CM, and 17.7 ± 15 in EM (P=.001). Adjusted means for EE were 24.6 ± 2.6 in CM patients, 16.2 ± 2.6 in EM patients, and 13.4 ± 2.3 (P=.03) in the healthy group. MIDAS scale scores were inversely correlated to PA (P<.05) DISCUSSION: Our results suggest that the level of EE at work is higher in EM than in CM patients, while PA levels decrease as impact on the MIDAS scale increases. The Maslach scale is a potentially useful tool for studying migraine impact. Surprisingly, EE is higher in patients with fewer episodes; this tendency could be related to stress adaptation mechanisms present in patients with chronic illness.

[Laparoscopic splenectomy in hematologic diseases in children. Analysis of 11-year experience]. / Esplenectomía laparoscópica por enfermedades hematológicas en niños. Análisis de 11 años.

OBJECTIVES: A common indication for splenectomy in children is hematologic diseases. Indications, clinical course and complications of laparoscopic splenectomy are shown; factors associated with open conversion are analyzed. MATERIAL AND METHODS: Retrospective, longitudinal, descriptive series of laparoscopic splenectomy during 11 years and its long-term follow-up. RESULTS: We studied 88 laparoscopic splenectomies. Average age was 9 years and weight 30 kg. The indication was hemolytic anemia in 77% and thrombocytopenic purpura in 18%. Eleven percent was operated with severe thrombocytopenia and two patients urgently; cholecystectomy was done in 13%. The median surgical time was 180 minutes and bleeding 100 ml. Conversion rate was 5.7% mainly because of persistent bleeding, being risk bleeding greater than 300 ml and the need for red cell concentrate transfusion. The median length of stay was 3 days, longer in those affected by purpura. Three patients developed pneumonia and one, intra-abdominal abscess. Follow-up was 3.6 years average with two late complications. Treatment response was cure in 72%, improvement in 11.3% and failure in 6.8%. DISCUSSION: It is feasible to operate patients under 5 years of age and patients with anemia or thrombocytopenia at the time of surgery without major problems. The conversion rate is low and risk factors for conversion are bleeding more than 300 ml and needing to transfuse erythrocyte concentrate.

INTRODUCCION: Una indicación frecuente de esplenectomía en niños son las enfermedades hematológicas. Se muestran las indicaciones, curso clínico y complicaciones en niños con esplenectomía laparoscópica y se analizan los factores de conversión a cirugía abierta. MATERIAL Y METODOS: Estudio de cohorte, longitudinal, descriptivo de esplenectomía laparoscópica en un periodo de 11 años y su seguimiento a largo plazo. RESULTADOS: Se analizaron 88 esplenectomías laparoscópicas. Edad promedio 9 años y peso 30 kg. La indicación fue anemia hemolítica en el 77% y púrpura trombocitopénica en el 18%. El 11% se operó con trombocitopenia grave y dos pacientes en forma urgente, se hizo colecistectomía en el 13%. La mediana de tiempo quirúrgico fue de 180 minutos con sangrado de 100 ml. Se convirtió el 5,7% por sangrado persistente, siendo los factores de riesgo el sangrado mayor a 300 ml y la necesidad de transfusión de concentrado eritrocitario. La mediana de estancia fue 3 días, superior en los pacientes afectos de púrpura. Tres pacientes desarrollaron neumonía y uno, absceso intra-abdominal. El seguimiento promedio es de 3,6 años con dos complicaciones tardías. Hubo curación con normalización del hemograma y sin necesidad de transfusiones en el 72%, mejoría con necesidad de transfusiones ocasionales en el 11,3% y fallo con requerimientos transfusionales iguales a los preoperatorios en el 6,8% de los pacientes. DISCUSION: Es posible operar a pacientes menores de 5 años y a pacientes con anemia o trombocitopenia en el momento de la cirugía, sin mayor complicación. La tasa de reconversión es baja y los factores de riesgo para reconversión son un sangrado mayor de 300 ml y la necesidad de transfundir concentrado de hematíes.

Esplenectomía laparoscópica por enfermedades hematológicas en niños. Análisis de 11 años / Laparoscopic splenectomy in hematologic diseases in children. Analysis of 11-year experience

Introducción. Una indicación frecuente de esplenectomía en niños son las enfermedades hematológicas. Se muestran las indicaciones, curso clínico y complicaciones en niños con esplenectomía laparoscópica y se analizan los factores de conversión a cirugía abierta. Material y métodos. Estudio de cohorte, longitudinal, descriptivo de esplenectomía laparoscópica en un periodo de 11 años y su seguimiento a largo plazo. Resultados. Se analizaron 88 esplenectomías laparoscópicas. Edad promedio 9 años y peso 30 kg. La indicación fue anemia hemolítica en el 77% y púrpura trombocitopénica en el 18%. El 11% se operó con trombocitopenia grave y dos pacientes en forma urgente, se hizo colecistectomía en el 13%. La mediana de tiempo quirúrgico fue de 180 minutos con sangrado de 100 ml. Se convirtió el 5,7% por sangrado persistente, siendo los factores de riesgo el sangrado mayor a 300 ml y la necesidad de transfusión de concentrado eritrocitario. La mediana de estancia fue 3 días, superior en los pacientes afectos de púrpura. Tres pacientes desarrollaron neumonía y uno, absceso intra-abdominal. El seguimiento promedio es de 3,6 años con dos complicaciones tardías. Hubo curación con normalización del hemograma y sin necesidad de transfusiones en el 72%, mejoría con necesidad de transfusiones ocasionales en el 11,3% y fallo con requerimientos transfusionales iguales a los preoperatorios en el 6,8% de los pacientes. Discusión. Es posible operar a pacientes menores de 5 años y a pacientes con anemia o trombocitopenia en el momento de la cirugía, sin mayor complicación. La tasa de reconversión es baja y los factores de riesgo para reconversión son un sangrado mayor de 300 ml y la necesidad de transfundir concentrado de hematíes

Objectives. A common indication for splenectomy in children is hematologic diseases. Indications, clinical course and complications of laparoscopic splenectomy are shown; factors associated with open conversion are analyzed. Methods. Retrospective, longitudinal, descriptive series of laparoscopic splenectomy during 11 years and its long-term follow-up. Results. We studied 88 laparoscopic splenectomies. Average age was 9 years and weight 30 kg. The indication was hemolytic anemia in 77% and thrombocytopenic purpura in 18%. Eleven percent was operated with severe thrombocytopenia and two patients urgently; cholecystectomy was done in 13%. The median surgical time was 180 minutes and bleeding 100 ml. Conversion rate was 5.7% mainly because of persistent bleeding, being risk bleeding greater than 300 ml and the need for red cell concentrate transfusion. The median length of stay was 3 days, longer in those affected by purpura. Three patients developed pneumonia and one, intra-abdominal abscess. Follow-up was 3.6 years average with two late complications. Treatment response was cure in 72%, improvement in 11.3% and failure in 6.8%.Discussion. It is feasible to operate patients under 5 years of age and patients with anemia or thrombocytopenia at the time of surgery without major problems. The conversion rate is low and risk factors for conversion are bleeding more than 300 ml and needing to transfuse erythrocyte concentrate

Cerebellar abscesses caused by dog bite: a case report.

INTRODUCTION: Bites by house pets can be lethal or cause a series of catastrophic events with severe sequels, such as the loss of a limb or a systemic infection which may be life-endangering, especially in the case of children being bitten. PRESENTATION: A 2-year-old girl was attacked by a dog, causing lesions at the occipital region. This was treated initially as a superficial wound that became further complicated with two cerebellar abscesses. These abscesses required neurosurgical and antimicrobial treatment, with a satisfactory outcome. CONCLUSION: The precise and diligent evaluation of a lesion caused by an animal bite may prevent further life-endangering complications. To the best of our knowledge, there are no reports about cerebellar abscess caused by a dog bite. When cranial lesions are penetrating, an abscess must to be considered. We insist on the importance of medical evaluation and adequate treatment of such lesions.

Effect of exogenous melatonin on hepatic energetic status during ischemia/reperfusion: possible role of tumor necrosis factor-alpha and nitric oxide.

BACKGROUND: This study was designed to determine if the very potent antioxidant melatonin is able to reduce organ damage and improve energetic status in an in situ liver ischemia/reperfusion model. MATERIALS AND METHODS: Total hepatic ischemia was induced in rats by occlusion of the hepatic artery, portal vein, and bile duct. A portojugular shunt was inserted. After 60 min of ischemia, reperfusion was established for a period of 120 min. Rats were assigned to one group receiving systemic melatonin administration or to another receiving only normal saline. Variables were observed at preischemia, after 60 min of ischemia, and at 30, 60, and 120 min of reperfusion. RESULTS: Energy charge, measured as the arterial ketone body ratio, showed higher values in the melatonin group during the first 60 min of reperfusion. Rises in plasma nitrite, tumor necrosis factor (TNF)-alpha, aspartate aminotransferase, alanine aminotransferase, lipid peroxidation products, and inducible nitric oxide synthase (iNOS) expression were less severe with melatonin. Linear regression analysis demonstrated a significant correlation between nitrites and arterial ketone body ratio (R(2) = 0.2454). Bile production was higher with melatonin. Seven-day survival rates were 52% for control, 80% for melatonin, and 100% for sham groups. CONCLUSIONS: Exogenous melatonin is capable of preserving the functional and energetic status during ischemia/reperfusion which is associated with reduced concentrations of TNF-alpha and inhibited expression of iNOS and NO production. This improvement may be due to an adequate preservation of the hepatic mitochondrial redox status.

Blood flow rate and energy charge in the isolated perfused canine liver.

Background. Liver viability depends on blood flow rate, which varies among isolated perfused livers used in different studies. We aimed to identify the minimal blood flow capable of keeping the energy charge compatible with liver viability. Materials and methods. Isolated canine livers were assigned to different groups (n = 4) with blood flow rates of 0.5 (Group I), 1.0 (Group II), and 1.5 ml/g/min (Group III). Blood gases, hematocrit, and glucose were measured over 180 min. Nucleotides, serum osmolarity, and electrolytes were also measured. Morphological changes were recorded at the end of each experiment. Results. Acid-base balance was better in livers from Group III. Electrolytes, osmolarity, hematocrit, and glucose showed no differences. Higher energy charges correlated with higher blood flow rates. On histopathology, there was evidence of more hydrostatic pressure-related changes in Group III, with no difference in necrosis or inflammatory-related alterations. Conclusions. (1) Energy charge correlates strongly with blood flow rate. (2) A rate of 1.5 ml/g/min allows for a better electrolyte, osmolarity, and acid-base balance. (3) Morphological analysis is not a sensitive predictor of organ viability as assessed by energetic potential. (4) The minimal blood flow rate required to attain an energy charge above 0.75 is 1.33 ml/g/min.

Exogenous nitric oxide protects kidney from ischemia/reperfusion.

Blockade of NO production is followed by an increase in leukocyte rolling and adhesion resulting in some deleterious effects of ischemia. Preischemic administration of NO protects vascular integrity after reperfusion. Exogenous NO causes a direct reduction in leukocyte adhesion. This work was performed to test the hypothesis that exogenous NO administered during the preischemic period to the kidney alone, without coming into contact with the leukocytes, could also reduce leukocyte-endothelium adhesion. Adult rats were subjected to in situ isolation of the left kidney. Solutions were infused through the renal artery and drained through an incision in the renal vein, thus avoiding the systemic circulation. Group IC rats served as an ischemic control, and received 0.9% saline. Group NP received Na nitroprusside. Group S was a nonischemic control. Groups IC and NP were subjected to 75 min of renal ischemia. After this period, vascular structures were repaired and reperfusion allowed. A right nephrectomy was performed. Serum urea and creatinine, myeloperoxidase activity, and histopathological studies were carried out at different intervals after reperfusion. Survival at 15 days was 46%, 80%, and 100% in groups IC, NP, and S, respectively. Differences between groups for serum urea and creatinine were significant only during the first seven days. Myeloperoxidase values were significantly higher in group IC. All rats from group IC and only 20% from group NP showed histological evidence of necrosis. Thus, exogenous NO is protective and acts selectively upon the kidney, modulating its interactions with polymorphonuclear cells after ischemia/reperfusion.

A model of suture-induced urolithiasis with urographic control in the bladder of the rat.

The characteristics of a model of urolithiasis in the bladder of male Wistar rats were evaluated. Two techniques were compared: one knot of suture material through the bladder wall, or 15-throw knots inside the bladder. Rats were randomly assigned to one of six groups, according to the technique and suture material used (polyester, silk, or chromic catgut). An excretory urogram was performed at days 30, 60, and 90. At the moment of positive radiographic diagnosis, animals were sacrificed and stones were obtained. All rats were sacrificed at day 90 regardless of the x-ray results. Variables evaluated were average days to a positive urogram, average weight of all uroliths, and percentage of animals developing urolithiasis throughout the study. There were no statistical differences between groups for the average weight of stones, which ranged from 0.008 to 1.502 g for individual cases. All three materials were more lithogenic with the 15-throw knot inside technique. No significant differences were detected for lithogenesis criteria between suture materials. X-ray dispersion spectroscopy evidenced calcium phosphate composition of two stones from chromic catgut, and magnesium phosphate composition of two stones from chromic catgut, two from silk, and two from polyester. Neo-epithelization over the suture was confirmed microscopically in bladders with the one-throw technique. We conclude that (1) this is an effective model of urolithiasis, with predictability in time, composition, and amount of stone formation; (2) the presence of more suture material inside the bladder is more lithogenic; and (3) excretory urograms are highly sensitive and specific for the noninvasive diagnosis of bladder urolithiasis.

Vegetation-environment relationships based on a life-forms classification in a semiarid region of tropical Mexico.

Taking the view that morphological characteristics represent behavioral strategies of plants to cope with environmental pressures, we defined 18 life-forms, using multivariate classification techniques in a tropical semiarid ecosystem in Central Mexico. A multiple discriminant analysis confirmed the existence of these groups. A null model of random membership of species to life-forms was significantly different from our classification. Vegetation-environment relationships were examined with Detrended Canonical Correspondence Analysis (DCCA). Ordination axes were interpreted mainly be altitude and soil moisture. Response curves of life-forms along these gradients were explored fitting generalized linear models (GLIM's). We believe that the life-forms approach for the study of vegatation-environment relationships is a valid alternative to the traditional species approach usually used in physiological research because: i) life-forms number was found to be an excellent species diversity predictor, ii) this approach enables considerable reduction in the bulk of data without losing ecological information, and iii) life-forms represent ecological strategies per se and, they constitute an index of the number of different ways the desert's resources are utilized.

Vegetation-environment relatioship based on a life-forms classification in a semiarid region of Tropical Mexico

Taking the view that morphological characteristics represent behavioral strategies of plants to cope with environmental pressures, we defined 18 life-forms, using multivariate classification techniques in a tropical semiarid ecosystem in Central Mexico. A multiple discriminant analysis confirmed the existence of these groups. A null model of random membership of species to life-forms was significantly different from our classification. Vegetation-environment relationships were examined with Detrended Canonical orrespondence Analysis (DCCA). Ordination axes were interpreted mainly be altitude and soil moisture. Response curves of life-forms along these gradients were explored fitting generalized linear models (GLIM's). We believe that the life-forms approach for the study of vegatation-environment relationships is a valid alternative to the traditional species approach usually used in physiological research because: i) life-forms number was found to be an excellent species diversity predictor, ii) this approach enables considerable reduction in the bulk of data without losing ecological information, and iii) life-forms represent ecological strategies per se and, they constitute an index of the number of different ways the desert's resources are utilized