Measuring impulsivity in Parkinson's disease: a correlational and structural neuroimaging study using different tests.

BACKGROUND AND PURPOSE: Impulsivity is an aspect of personality and a major component of multiple neuropsychiatric conditions. In Parkinson's disease, it has been associated with the expression of impulse control disorders, a highly prevalent non-motor complication. Even though multiple tests of impulsivity have been used in this context, the impact of test choice has not been addressed. The aim was to evaluate whether different impulsivity measures in Parkinson's disease share substantial inter-scale and anatomical correlations or rather mirror different underlying phenomena. METHODS: In a consecutive sample of 89 Parkinson's disease patients without impulse control disorders, four common tests were evaluated assessing different aspects of impulsivity: impulsiveness trait, decisions under implicit risk with and without losses, and delay discounting. Correlations among test scores were analysed and each score was used as a regressor in a set of grey matter volume (GMV) voxel-based morphometry analyses to explore their brain structural correlates. RESULTS: No significant correlations were found between the different impulsivity tests. Furthermore, their structural brain correlates were divergent. Impulsiveness trait appeared to be associated with lower GMV in dorsal-lateral prefrontal cortices, implicit risk (with losses) with higher GMV in the left nucleus accumbens and lower left insular GMV, implicit risk (without losses) with higher GMV in the left lingual gyrus and lower GMV in the gyri recti and delay discounting with higher GMV in the left nucleus accumbens. CONCLUSIONS: In Parkinson's disease, different impulsivity measures reflect very dissimilar behavioural and brain structural correlates. Our results suggest that parkinsonian impulsivity is not a unitary phenomenon but rather a heterogeneous entity.

Impulse control disorders and dopaminergic treatments in Parkinson's disease.

A group of disorders sharing a failure to resist an impulse to perform a typically pleasurable activity that is finally harmful to the person or to others are known under the common denomination of impulse control disorders (ICDs). These behaviors, possibly previously neglected by lack of awareness, are increasingly reported among PD patients. Compelling evidence has stressed the relation between dopaminergic replacement and development of ICDs in PD, especially but not exclusively, with dopamine agonist therapy. Besides dopaminergic replacement, younger age, smoking habit, presence of familiar gambling problems and alcohol abuse can increase the risk. ICDs in PD may greatly affect patients and caregivers quality of life, stressing the importance of their screening. Management strategies include a careful use of dopaminergic therapy using the lowest effective doses.

Management of Parkinson's disease and other movement disorders in woman of childbearing age: Part 1. / Manejo de la enfermedad de Parkinson y otros trastornos del movimiento en mujeres en edad fértil: Parte 1.

INTRODUCTION: The main challenge of Parkinson's disease in women of childbearing age is managing symptoms and drugs during pregnancy and breastfeeding. The increase in the age at which women are having children makes it likely that these pregnancies will become more common in future. OBJECTIVES: This study aims to define the clinical characteristics of women of childbearing age with Parkinson's disease and the factors affecting their lives, and to establish a series of guidelines for managing pregnancy in these patients. RESULTS: This consensus document was developed through an exhaustive literature search and a discussion of the available evidence by a group of movement disorder experts from the Spanish Society of Neurology. CONCLUSIONS: Parkinson's disease affects all aspects of sexual and reproductive health in women of childbearing age. Pregnancy should be well planned to minimise teratogenic risk. A multidisciplinary approach should be adopted in the management of these patients in order to take all relevant considerations into account.

Management of Parkinson's disease and other movement disorders in women of childbearing age: Part 2. / Manejo de la enfermedad de Parkinson y otros trastornos del movimiento en mujeres en edad fértil: parte 2.

INTRODUCTION: Many diseases associated with hyperkinetic movement disorders manifest in women of childbearing age. It is important to understand the risks of these diseases during pregnancy, and the potential risks of treatment for the fetus. OBJECTIVES: This study aims to define the clinical characteristics and the factors affecting the lives of women of childbearing age with dystonia, chorea, Tourette syndrome, tremor, and restless legs syndrome, and to establish guidelines for management of pregnancy and breastfeeding in these patients. RESULTS: This consensus document was developed through an exhaustive literature search and a discussion of the content by a group of movement disorder experts from the Spanish Society of Neurology. CONCLUSIONS: We must evaluate the risks and benefits of treatment in all women with hyperkinetic movement disorders, whether pre-existing or with onset during pregnancy, and aim to reduce effective doses as much as possible or to administer drugs only when necessary. In hereditary diseases, families should be offered genetic counselling. It is important to recognise movement disorders triggered during pregnancy, such as certain types of chorea and restless legs syndrome.

Depression is Associated with Impulse-compulsive Behaviors in Parkinson's disease.

BACKGROUND: Depression and impulse control disorders (ICDs) are both common in Parkinson's disease (PD) patients and their coexistence is frequent. Our aim was to determine the relationship between depression and impulsive-compulsive behaviors (ICBs) in a large cohort of PD patients. METHODS: PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016 to November 2017 were included in the study. The QUIP-RS (Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale) was used for screening ICDs (cutoff points: gambling ≥6, buying ≥8, sex≥8, eating≥7) and compulsive behaviors (CBs) (cutoff points: hobbyism-punding ≥7). Mood was assessed with the BDI-II (Beck Depression Inventory - II) and major, minor, and subthreshold depression were defined. RESULTS: Depression was more frequent in PD patients with ICBs than in those without: 66.3% (69/104) vs 47.5% (242/509); p<0.0001. Major depression was more frequent in this group as well: 22.1% [23/104] vs 14.5% [74/509]; p=0.041. Considering types of ICBs individually, depression was more frequent in patients with pathological gambling (88.9% [8/9] vs 50.2% [303/603]; p=0.021), compulsive eating behavior (65.9% [27/41] vs 49.7% [284/572]; p=0.032), and hobbyism-punding (69% [29/42] vs 49.4% [282/571]; p=0.010) than in those without, respectively. The presence of ICBs was also associated with depression (OR=1.831; 95%CI 1.048-3.201; p=0.034) after adjusting for age, sex, civil status, disease duration, equivalent daily levodopa dose, antidepressant treatment, Hoehn&Yahr stage, non-motor symptoms burden, autonomy for activities of daily living, and global perception of QoL. LIMITATIONS: Cross-sectional design. CONCLUSIONS: Depression is associated with ICBs in PD. Specifically, with pathological gambling, compulsive eating behavior, and hobbyism-punding.

Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours: results from the COPPADIS cohort.

The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose.

Quality of life and non-motor symptoms in Parkinson's disease patients with subthreshold depression.

BACKGROUND: The role of subthreshold depression (subD) in Parkinson's Disease (PD) is not clear. The present study aimed to compare the quality of life (QoL) in PD patients with subD vs patients with no depressive disorder (nonD). Factors related to subD were identified. MATERIAL AND METHODS: PD patients and controls recruited from the COPPADIS cohort were included. SubD was defined as Judd criteria. The 39-item Parkinson's disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8) were used to assess QoL. RESULTS: The frequency of depressive symptoms was higher in PD patients (n = 694) than in controls (n = 207) (p < 0.0001): major depression, 16.1% vs 7.8%; minor depression, 16.7% vs 7.3%; subD, 17.4% vs 5.8%. Both health-related QoL (PDQ-39; 18.1 ±â€¯12.8 vs 11.6 ±â€¯10; p < 0.0001) and global QoL (EUROHIS-QOL8; 3.7 ±â€¯0.5 vs 4 ±â€¯0.5; p < 0.0001) were significantly worse in subD (n = 120) than nonD (n = 348) PD patients. Non-motor Symptoms Scale (NMSS) total score was higher in subD patients (45.9 ±â€¯32 vs 29.1 ±â€¯25.8;p < 0.0001). Non-motor symptoms burden (NMSS;OR = 1.019;95%CI 1.011-1.028; p < 0.0001), neuropsychiatric symptoms (NPI; OR = 1.091; 95%CI 1.045-1.139; p < 0.0001), impulse control behaviors (QUIP-RS; OR = 1.035; 95%CI 1.007-1063; p = 0.013), quality of sleep (PDSS; OR = 0.991; 95%CI 0.983-0.999; p = 0.042), and fatigue (VAFS-physical; OR = 1.185; 95%CI 1.086-1.293; p < 0.0001; VAFS-mental; OR = 1.164; 95%CI 1.058-1.280; p = 0.0001) were related to subD after adjustment to age, disease duration, daily equivalent levodopa dose, motor status (UPDRS-III), and living alone. CONCLUSIONS: SubD is a frequent problem in patients with PD and is more prevalent in these patients than in controls. QoL is worse and non-motor symptoms burden is greater in subD PD patients.

Motor changes during sertraline treatment in depressed patients with Parkinson's disease*.

BACKGROUND: Pharmacological interventions to treat depressive symptoms associated with Parkinson's disease (PD) are limited. Whether selective serotonine re-uptake inhibitors increase parkinsonism or have clinically significant interactions with antiparkinsonian drugs is unresolved. PURPOSE: We used a naturalistic approach to prospectively investigate the long-term effects on motor status of adding sertraline in a large sample of community-dwelling PD patients with depressive symptoms. METHODS: Main outcome measure was the motor part of the Unified PD Rating Scale (UPDRS) at baseline and at 1-, 3-, and 6-month follow-up. Secondary measures were the change in antiparkinsonian drugs expressed as total levodopa equivalent dose and the scores of the Hospital Anxiety and Depression Scale (HADS). Of the 374 patients included, 310 (82%) completed the study. RESULTS: Treatment with sertraline (mean dose 66.0 +/- 29.8 mg) resulted in improvement in all UPDRS domains along with a significant decrease of the HADS scores. A modest but significant increase of the total dose of levodopa, without significant change of total levodopa equivalent dose, was observed. Almost 8% of patients discontinued medication for adverse events, mainly related to the gastrointestinal system. CONCLUSIONS: Although worsening of tremor was observed in some patients, active management of depression with sertraline appears to have a positive impact on parkinsonism.

Bilateral deep brain stimulation in Parkinson's disease: a multicentre study with 4 years follow-up.

Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n = 49) or globus pallidus internus (GPi, n = 20) included in a multicentre study. Patients were assessed preoperatively and at 1 year and 3-4 years after surgery. The primary outcome measure was the change in the 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) at 3-4 years. Stimulation of the STN or GPi induced a significant improvement (50 and 39%; P < 0.0001) of the 'off' medication UPDRS-III score at 3-4 years with respect to baseline. Stimulation improved cardinal features and activities of daily living (ADL) (P < 0.0001 and P < 0.02 for STN and GPi, respectively) and prolonged the 'on' time spent with good mobility without dyskinesias (P < 0.00001). Daily dosage of levodopa was significantly reduced (35%) in the STN-treated group only (P < 0.001). Comparison of the improvement induced by stimulation at 1 year with 3-4 years showed a significant worsening in the 'on' medication motor states of the UPDRS-III, ADL and gait in both STN and GPi groups, and speech and postural stability in the STN-treated group. Adverse events (AEs) included cognitive decline, speech difficulty, instability, gait disorders and depression. These were more common in patients treated with DBS of the STN. No patient abandoned treatment as a result of these side effects. This experience, which represents the first multicentre study assessing the long-term efficacy of either STN or GPi stimulation, shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.

A randomized placebo-controlled comparative trial of gabapentin and propranolol in essential tremor.

BACKGROUND: New medication is needed to treat essential tremor. Preliminary evidence suggests that gabapentin may be effective in the treatment of this disorder. OBJECTIVE: To study the effects of gabapentin in a comparative, double-blind, crossover, placebo-controlled trial of patients who have essential tremor. PATIENTS AND METHODS: 16 patients with essential tremor (6 with a new onset and 10 with a 2-week washout period of previous treatment with propranolol hydrochloride) received gabapentin (Neurontin), 400 mg 3 times daily; propranolol hydrochloride, 40 mg 3 times daily; and placebo for 15 days with a 1-week washout period between treatments. MAJOR OUTCOME MEASURES: Major outcome evaluations consisted of a Tremor Clinical Rating Scale, accelerometric recordings, and a self-reported disability scale obtained before drug intake on study days 1 and 15 of each treatment period. In addition, the initial (day 1) and superimposed (day 15) drug effects were studied before and 2, 4, 6, and 8 hours after drug intake. RESULTS: At day 15, both gabapentin and propranolol demonstrated significant and comparable efficacy in reducing tremor from baseline in all tremor measures. The initial drug effects evaluated through accelerometry revealed no significant changes with the use of a placebo, but gabapentin and propranolol use significantly reduced tremor power. CONCLUSION: Gabapentin may be useful for the treatment of essential tremor.

Prospective study of new-onset seizures in patients with human immunodeficiency virus infection: etiologic and clinical aspects.

OBJECTIVE: To determine the frequency and etiologic and clinical aspects of new-onset seizures in patients with human immunodeficiency virus (HIV) infection. DESIGN: A prospective survey of an HIV-infected patient cohort. SETTING: Outpatients and inpatients in a university hospital in Barcelona, Spain. PATIENTS: Five hundred fifty HIV-infected patients recruited over 1 year. MAIN OUTCOME MEASURE: Analysis of new-onset seizures, with detailed medical history and appropriate workup. RESULTS: Seventeen HIV-infected patients (3%) had a new-onset seizure during the study period. Fourteen (82%) of 17 patients had acquired immunodeficiency syndrome diagnosed according to the 1993 CDC Expanded AIDS Definition. Mean latency (+/-SD) between diagnosis of HIV infection and the first seizure was 60.7+/-37.6 months. Seizure cause was drug toxicity in 8 patients (47%) and intracranial lesion in 6 patients (35.3%). Two patients had seizures related to metabolic derangements. No cause was found in 1 case. The first seizure was generalized in 12 patients (70.6%), simple partial motor seizure in 2 (11.8%), and simple partial seizure evolving to generalized seizure in 3 (17.6%). We found partial seizures in 66.6% of patients who had intracranial lesions. Most patients were treated with phenytoin, which was well tolerated and effective in controlling seizures. CONCLUSIONS: New-onset seizures are infrequent in patients with HIV. In most cases a definite or probable cause is identified, which is usually related to toxic and/or metabolic factors. Most seizures are generalized, and partial seizures suggest a focal cerebral lesion.

Mania following deep brain stimulation for Parkinson's disease.

Three patients with PD developed manic behavior after bilateral implantation of electrodes for deep-brain stimulation (DBS). Common to all three patients were manic symptoms unremitting after levodopa reduction or stimulation "off," lower electrodes positioning caudal to the subthalamic nucleus area, postoperative DBS with the lower contacts (0) of the quadripolar electrodes, and resolution of the manic episodes coinciding with stimulation through higher contacts.

A six-month study of pergolide and levodopa in de novo Parkinson's disease patients.

Formal studies examining the antiparkinsonian efficacy of levodopa and pergolide monotherapy in de novo Parkinson's disease (PD) are lacking. The authors conducted a preliminary, 6-month, open-label parallel experimental study with de novo consecutive PD patients who were randomly assigned to three daily doses of pergolide (n = 10; mean age, 63.7 years; mean Hohen & Yahr score, 1.5; mean final dose, 2.8 mg daily) or levodopa (n = 10; mean age, 67.3 years; mean Hohen & Yahr score, 1.8; mean final dose, 435 mg daily). Doses were titrated individually according to patients' evaluation of their own functional ability, known side-effects, and a monthly administration of the Unified Parkinson's Disease Rating Scale (UPDRS) by a clinician blind to the treatment regime. All patients completed the study. There were no significant basal differences between groups and no significant treatment ortreatment-by-time effects in UPDRS scores (according to two-way ANOVA). A clear time effect was observed for most of the functional and motor variables (p < 0.001), with significant improvement during the first month that was maintained for the duration of the study in both groups. Side effects were mild, transient, and comparable. In this preliminary study, pergolide and levodopa exhibited similar symptomatic efficacy and incidence of side effects in the short-term treatment of de novo PD patients at their usual age of clinical manifestation.

[Postural tremor: clinical and neurophysiological study in a consecutive series of 300 patients]. / Temblor postural: estudio clínico y neurofisiológico en una serie consecutiva de 300 pacientes.

BACKGROUND: There are few studies analysing the clinical and neurophysiological characteristics of postural tremor in Spain. PATIENTS AND METHOD: We studied prospectively 300 consecutive patients referred to a Movement Disorders Section because of postural tremor of the upper limbs. Syndromic diagnosis of postural tremor was made according to clinical criteria with the aid of neurophysiological criteria (accelerometric and EMG data). In patients diagnosed with essential tremor (ET), diagnostic sensitivity studies, correlation studies of clinical and neurophysiological data and multivariate analysis were performed. RESULTS: Most frequent syndromic diagnoses were ET (77%), parkinsonian postural tremor (10%) and exaggerated physiological tremor (6%). Fifty percent of ET patients reported having affected relatives, and 7% reported that their tremor improved with alcohol. Mostly specific variables for the diagnosis of ET were: affected relatives (77%), cephalic tremor (80%), alcohol improvement (100%), and synchronous EMG pattern (79%). The presence of affected relatives and a synchronous EMG pattern were significant predictive variables on a multivariate analysis. We found a significant correlation between age at time of consulting and frequency (rs = 0.561; p < 0.0005) and amplitude (rs = 0.470; p < 0.0005) of tremor. CONCLUSIONS: In the present study, ET was the most common cause of reference for postural tremor. Selective clinical data and neurophysiological evaluation are useful for the diagnosis of postural tremor.

[Delayed central pain associated with a sub-insular hematoma followed by parieto-occipital tumor. Favorable effects of chronic stimulation of the ventral posterior thalamic nucleus]. / Dolor central retardado asociado a hematoma subinsular seguido por tumor parietoccipital. Efecto favorable de la estimulación crónica del núcleo VPL talámico.

INTRODUCTION: Déjerine and Roussy reported thalamic syndrome, chronic pain after a vascular lesion in the thalamus, in 1906. Posterior clinical observations allowed know that the same clinical picture can be observed after lesions in other parts of the central nervous system. Due to the fact that the more frequent etiology is vascular, nowadays the term central poststroke pain syndrome is preferred. CLINICAL CASE: We report a patient who suffered a left subinsular hematoma when he was 62 years old. Four years later he started complaining burning constant pain in the right side of the body with crisis of lancinating pain. Also allodynia was observed in the face and right arm. MRI disclosed a necrotic lesion at the level of the left subinsular region. CONCLUSIONS: The lancinating pain and the allodynia were properly controlled by deep brain stimulation with an electrode placed stereotactically at the level of VPL nucleus of the left thalamus. Five months later there was a recurrence of the pain, a CT disclosed a tumour in the parietal region with an important shift of the midline and migration of the electrode out the thalamus. A biopsy disclosed tumoral necrosis. The pathophysiology of the central poststroke pain and effectivity of the deep brain stimulation in this cases are discussed.

Gaba and serotonin molecular neuroimaging in essential tremor: a clinical correlation study.

BACKGROUND: Essential tremor is the most common movement disorder in adults, but its exact etiology and pathophysiology are still not fully understood. There is some consensus, however, about the involvement of the cerebellum and accumulating evidence points towards a dysfunction of the gabaergic system. We hypothesize that the serotonin neurotransmission system may also play a role as it does in tremor in Parkinson disease. This study aimed to investigate the association between the severity of tremor symptoms and the gabaergic and serotoninergic neurotransmission systems in essential tremor. MATERIAL AND METHODS: We measured the tremor clinical rating scale score and acquired DASB and Flumazenil PET scans in 10 patients who presented with essential tremor at different stages of clinical severity. Statistically significant correlations were sought between the scale scores and parametric binding potential images. RESULTS: The correlation analysis of cerebellar Flumazenil uptake and tremor clinical rating scale scores reached statistical significance (R2 = 0.423, p = 0.041), whereas no association was detected in the DASB scans. CONCLUSIONS: The severity of tremor correlated with the abnormalities found in GABA receptor binding, suggesting a primary gabaergic deficiency or a functional abnormality at the level of GABA(A) receptor subtypes. These results may assist in the rational development of new pharmacological treatments for essential tremor.

[Parkinson disease and cognition]. / Enfermedad de Parkinson y cognición.

Parkinson's Disease patients may have cognitive deficits, which may vary from mild focal specific deficits to global dementia. Executive functions, working memory, visuoespatial functions and internal control of attention are the main affected cognitive areas. The dopaminergic hypothesis suggests that dopaminergic transmission is involved in most altered cognitive processes. However, other neuronal systems are probably implicated, and the improvement of the cognitive function after dopaminergic replacement is incomplete and not seen in all cognitive tasks. The prevalence of dementia in Parkinson's disease is estimated in 15-25%. The pathologic hallmarks may be similar to that seen in Alzheimer's disease. However, in Parkinson's disease patients pure subcortical alterations are able to produce a severe cognitive impairment, such as lost of dopaminergic neurones from substantia nigra to caudate nucleus and frontal areas. Comprehension of the relationship between depression and dementia in Parkinson's disease patients is incomplete. Parkinson's disease patients with depression show poor neuropsychological performance, especially in frontal tasks, but it is unclear whether depression can be considered a risk factor for the development of dementia in Parkinson's disease.

[Weight gain after functional surgery for Parkinsons disease]. / Ganancia ponderal después de la cirugía funcional en la enfermedad de Parkinson.

BACKGROUND: The origin of weight gain after functional surgery for Parkinson's disease (PD) is incompletely known. We have done a prospective study to determine the possible causes of weight gain after pallidal and subthalamic surgery. PATIENTS AND METHOD: Twenty-seven patients were studied (9 unilateral pallidotomy, 9 bilateral deep brain stimulation (DBS) of palidum, and 9 bilateral DBS of suthalamic nucleus) with a follow-up of 12 months. The relationship between weight gain and changes in motor situation, levodopa dosage, dyskinesias, dysphagia and mood state were analyzed. The patients filled a questionnaire about the severity and etiology of weight gain. RESULTS: Weight gain was noted in 26 patients (mean of 4.7 kg at 12 months). It was found a significant correlation between weight gain and improvement of dyskinesias (AIMS) (r = 0.461; p = 0.023), the scores of the UPDRS part III, (r = 0.479; p = 0.028), and a significant inverse correlation with the pre-operative weight of the patient (r = 0.399; p = 0.050). Weight gain was most pronounced with bilateral than unilateral pallidal surgery (p = 0.021). The majority of patients referred weight gain as an slight adverse event and secondary to the improvement of dyskinesias. CONCLUSION: Functional surgery for PD, independently of the surgical target, provokes weight gain which is benign in the majority of cases. Reduction of energy expenditure with respect to the pre-operative situation would be the responsible of that phenomenon.