Integrating Somatosensory Information Over Time.

Our choices are often informed by temporally integrating streams of sensory information. This has been well demonstrated in the visual and auditory domains, but the integration of tactile information over time has been less studied. We designed an active touch task in which participants explored a spheroid-shaped object to determine its inclination with respect to the horizontal plane (inclined to the left or the right). In agreement with previous findings, our results show that more errors, and longer decision times, accompany difficult decisions (small inclination angles). To gain insight into the decision-making process, we used a time-controlled task in which the experimenter manipulated the time available for tactile exploration on a trial-by-trial basis. The behavioral results were fit with a bounded accumulation model and an independent sampling model that assumes no sensory accumulation. The results of model fits favor an accumulation-to-bound mechanism and suggest that participants integrate the first 600 ms of 1800 ms-long stimuli. This means that the somatosensory system benefits from longer streams of information, although it does not make use of all available evidence.

Tactile object categories can be decoded from the parietal and lateral-occipital cortices.

The visual system classifies objects into categories, and distinct populations of neurons within the temporal lobe respond preferentially to objects of a given perceptual category. We can also classify the objects we recognize with the sense of touch, but less is known about the neuronal correlates underlying this cognitive function. To address this question, we performed a multivariate pattern analysis (MVPA) of functional magnetic resonance imagining (fMRI) activity to identify the cortical areas that can be used to decode the category of objects explored with the hand. We observed that tactile object category can be decoded from the activity patterns of somatosensory and parietal areas. Importantly, we found that categories can also be decoded from the lateral occipital complex (LOC), which is a multimodal region known to be related to the representation of object shape. Furthermore, a hyperalignment analysis showed that activity patterns are similar across subjects. Our results thus indicate that tactile object recognition generates category-specific patterns of activity in a multisensory area known to encode objects, and that these patterns have a similar functional organization across individuals.

Incidence of pain flare following palliative radiotherapy for symptomatic bone metastases: multicenter prospective observational study.

BACKGROUND: Palliative radiotherapy (RT) is an effective treatment for symptomatic bone metastases. Pain flare, a transient worsening of the bone pain after RT, has been described in previous reports with different incidence rates. The aim of the study was to prospectively evaluate the incidence of pain flare following RT for painful bone metastases and evaluate its effects on pain control and functionality of the patients. METHODS: Between June 2010 and June 2014, 204 patients were enrolled in this study and 135 patients with complete data were evaluable. Pain flare was defined as a 2- point increase in worst pain score as compared with baseline with no decrease in analgesic intake or a 25% increase in analgesic intake as compared with baseline with no decrease in worst pain score. All pain medications and worst pain scores were collected before, daily during, and for 10 days after RT. The Brief Pain Inventory (BPI) was filled out on the pretreatment and at the 4 weeks follow-up visit. RESULTS: There were 90 men (66.7%) and 45 women (33.3%). Mean age was 66 years (SD 9.8). The most common primary cancer site was lung in 42 patients (31.1%), followed by prostate in 27 patients (20.0%). Forty-two patients (31.1%) patients received a single fraction of 8 Gy and 83 (61.5%) received 20 Gy in five fractions. The overall pain flare incidence across all centers was 51/135 (37.7%). The majority of pain flares occurred on days 1-5 (88.2%). The mean duration of the pain flare was 3 days (SD: 3). There were no significant relationships between the occurrence of pain flare and collected variables. All BPI items measured four weeks after end of RT showed significant improvement as compared with pretreatment scores (p < 0.001). No significant differences in BPI time trends were found between patients with and without flare pain. CONCLUSION: Pain flare is a common event, occurring in nearly 40% of the patients that receive palliative RT for symptomatic bone metastases. This phenomenon is not a predictor for pain response.

Should PET/CT be implemented in the routine imaging work-up of locally advanced head and neck squamous cell carcinoma? A prospective analysis.

PURPOSE: The objective of this study was to determine the incremental staging information provided by positron emission tomography/computed tomography (PET/CT) and its impact on management plans in patients with untreated stage III-IV head and neck squamous cell carcinoma (HNSCC). METHODS: We prospectively studied, between September 2011 and February 2013, 84 consecutive patients [median age 63.5 years (39-84); 73 men] with histologically confirmed HNSCC. First, based on a conventional work-up (physical examination, CT imaging of the head, neck and chest), the multidisciplinary Head and Neck Tumour Board documented the TNM stage and a management plan for each patient, outlining the modalities to be used, including surgery, radiation therapy (RT), chemotherapy or a combination. After release of the PET/CT results, new TNM staging and management plans were agreed on by the multidisciplinary Tumour Board. Any changes in stage or intended management due to the PET/CT findings were then analysed. The impact on patient management was classified as: low (treatment modality, delivery and intent unchanged), moderate (change within the same treatment modality: type of surgery, radiation technique/dose) or high (change in treatment intent and/or treatment modality → curative to palliative, or surgery to chemoradiation or detection of unknown primary tumour or a synchronous second primary tumour). TNM stage was validated by histopathological analysis, additional imaging or follow-up. Accuracy of the conventional and PET/CT-based staging was compared using McNemar's test. RESULTS: Conventional and PET/CT stages were discordant in 32/84 (38 %) cases: the T stage in 2/32 (6.2 %), the N stage in 21/32 (65.7 %) and the M stage 9/32 (28.1 %). Patient management was altered in 22/84 (26 %) patients, with a moderate impact in 8 (9.5 %) patients and high impact in 14 (16.6 %) patients. PET/CT TNM classification was significantly more accurate (92.5 vs 73.7 %) than conventional staging with a p value < 0.001 (McNemar's test). CONCLUSION: PET/CT should be implemented in the routine imaging work-up of stage III-IV HNSCC.

Impact of intraoperative MRI/TRUS fusion on dosimetric parameters in cT3a prostate cancer patients treated with high-dose-rate real-time brachytherapy.

PURPOSE: The purpose of this study was to evaluate the impact of intraoperative MRI/TRUS fusion procedure in cT3a prostate cancer patients treated with high-dose-rate (HDR) real-time brachytherapy. MATERIAL AND METHODS: Prostate gland, dominant intraprostatic lesions (DILs), and extracapsular extension (ECE) were delineated in the pre-brachytherapy magnetic resonance images (MRI) of 9 consecutive patients. The pre-implant P-CTVUS (prostate clinical target volume) was defined as the prostate seen in the transrectal ultrasound (TRUS) images. The CTVMR includedthe prostate with the ECE image (ECE-CTV) as defined on the MRI. Two virtual treatment plans were performed based on the MRI/TRUS fusion images, the first one prescribing 100% of the dose to the P-PTVUS, and the second prescribing to the PTVMR. The implant parameters and dose-volume histogram (DVH) related parameters of the prostate, OARs, and ECE were compared between both plans. RESULTS: Mean radial distance of ECE was 3.6 mm (SD: 1.1). No significant differences were found between prostate V100, V150, V200, and OARs DVH-related parameters between the plans. Mean values of ECE V100, V150, and V200 were 85.9% (SD: 15.1), 18.2% (SD: 17.3), and 5.85% (SD: 7) when the doses were prescribed to the PTVUS, whereas ECE V100, V150, and V200 were 99.3% (SD: 1.2), 45.8% (SD: 22.4), and 19.6% (SD: 12.6) when doses were prescribed to PTVMR (p = 0.028, p = 0.002 and p = 0.004, respectively). CONCLUSIONS: TRUS/MRI fusion provides important information for prostate brachytherapy, allowing for better coverage and higher doses to extracapsular disease in patients with clinical stage T3a.

The parietal cortices participate in encoding, short-term memory, and decision-making related to tactile shape.

We routinely identify objects with our hands, and the physical attributes of touched objects are often held in short-term memory to aid future decisions. However, the brain structures that selectively process tactile information to encode object shape are not fully identified. In this article we describe the areas within the human cerebral cortex that specialize in encoding, short-term memory, and decision-making related to the shape of objects explored with the hand. We performed event-related functional magnetic resonance imaging in subjects performing a shape discrimination task in which two sequentially presented objects had to be explored to determine whether they had the same shape or not. To control for low-level and nonspecific brain activations, subjects performed a temperature discrimination task in which they compared the temperature of two spheres. Our results show that although a large network of brain structures is engaged in somatosensory processing, it is the areas lining the intraparietal sulcus that selectively participate in encoding, maintaining, and deciding on tactile information related to the shape of objects.

Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy?

INTRODUCTION: In severe cases refractory to medical treatment, APC appears to be the preferred alternative to control persistent rectal bleeding of patients with chronic radiation proctitis. Although successful outcomes have been demonstrated in patients previously treated with moderate doses of radiotherapy, there is reluctance towards its indication due to the concern of severe adverse events in patients treated with high doses of radiation. OBJECTIVES: The aim of this study was to assess the efficacy and toxicity of APC in the management of bleeding radiationinduced proctitis in patients treated with high doses of radiation for prostate cancer. METHODS AND MATERIALS: Data from 30 patients were treated with APC due to chronic radiation proctitis, were reviewed retrospectively. All cases had prostate cancer and 9 of them (30 %) underwent previous radical prostatectomy. The median dose of conformal 3D External Beam Radiotherapy (EBRT) delivered was 74 Gy (range 46-76). Median rectal D1cc and D2cc was 72.5 and 72.4 Gy respectively. Median rectal V70, V60 and V40 was 12, 39.5 and 80 %. Cardiovascular and digestive disease, diabetes, smoking behaviour, lowest haemoglobin and transfusion requirements were recorded. Indications for treatment with APC were anemia and persistent bleeding despite medical treatment. Argon gas flow was set at 1.8 l/min with an electrical power setting of 50 W. RESULTS: Median age of all patients was 69.6 years. The median lowest haemoglobin level was 9.6 g/dL. Median time between completion of radiotherapy and first session of APC was 13 months. Ninety-four therapeutic sessions were performed (median 3 sessions). Median time follow-up was 14.5 months (range 2-61). Complete response with resolved rectal bleeding was achieved in 23 patients (77 %), partial response in 5 (16 %) and no control in 2 (6 %). No patients required transfusion following therapy. Two patients developed long-term (> 6 weeks) grade 2 rectal ulceration and grade 2 rectal incontinence, respectively. CONCLUSIONS: The argon plasma coagulation is an effective and safe management option in patients with medically refractory rectal bleeding after high doses of radiation for prostate cancer.

Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy? / ¿Es la coagulación con plasma argón una opción terapéutica eficaz y segura en pacientes con proctitis crónica actínica tras dosis altas de radioterapia?

Introduction: In severe cases refractory to medical treatment, APC appears to be the preferred alternative to control persistent rectal bleeding of patients with chronic radiation proctitis. Although successful outcomes have been demonstrated in patients previously treated with moderate doses of radiotherapy, there is reluctance towards its indication due to the concern of severe adverse events in patients treated with high doses of radiation. Objectives: The aim of this study was to assess the efficacy and toxicity of APC in the management of bleeding radiationinduced proctitis in patients treated with high doses of radiation for prostate cancer. Methods and materials: Data from 30 patients were treated with APC due to chronic radiation proctitis, were reviewed retrospectively. All cases had prostate cancer and 9 of them (30 %) underwent previous radical prostatectomy. The median dose of conformal 3D External Beam Radiotherapy (EBRT) delivered was 74 Gy (range 46-76). Median rectal D1cc and D2cc was 72.5 and 72.4 Gy respectively. Median rectal V70, V60 and V40 was 12, 39.5 and 80 %. Cardiovascular and digestive disease, diabetes, smoking behaviour, lowest haemoglobin and transfusion requirements were recorded. Indications for treatment with APC were anemia and persistent bleeding despite medical treatment. Argon gas flow was set at 1.8 l/min with an electrical power setting of 50 W. Results: Median age of all patients was 69.6 years. The median lowest haemoglobin level was 9.6 g/dL. Median time between completion of radiotherapy and first session of APC as 13 months. Ninety-four therapeutic sessions were performed (median 3 sessions). Median time follow-up was 14.5 months (range 2-61). Complete response with resolved rectal bleeding was achieved in 23 patients (77 %), partial response in 5 (16 %) and no control in 2 (6 %). No patients required transfusion following therapy. Two patients developed long-term (> 6 weeks) grade 2 rectal ulceration and grade 2 rectal incontinence, respectively. Conclusions: The argon plasma coagulation is an effective and safe management option in patients with medically refractory rectal bleeding after high doses of radiation for prostate cancer (AU)

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Detection of risk factors that influence weight loss in patients undergoing radiotherapy.

AIM: To identify risk factors that influence weight loss in patients receiving radiotherapy. BACKGROUND: It is a well-known fact that cancer patients can be affected by malnutrition at the onset of the disease and during treatment due to the toxicity. Pretreatment weight loss alone does not predict those who will need nutritional supplementation. Instead, a variety of nutritional and tumor related factors needs to be taken into account. MATERIAL AND METHODS: A retrospective study was conducted on 129 patients with different tumor locations. Weight loss was evaluated during radiotherapy and one month after treatment. The impact of age, ECOG, chemotherapy, pretreatment weight loss, tumor location, previous surgery and TNM were analyzed. We aimed to identify a high-risk group of patients before starting treatment. RESULTS: The average net weight loss during radiotherapy and one month after treatment for this group of patients was 0.68 kg and 1.6 kg, respectively. Median weight loss during radiotherapy was 2.6 kg for head and neck (HN) patients and 0.27  kg for other tumor sites (p = 0.028). Median weight loss one month after radiotherapy was 3.7 kg for HN patients and 1.1 kg for the rest of the patients (p = 0.034). The median weight loss one month after treatment was 3.2 kg for patients receiving chemotherapy and 0.5 kg for those patients who did not receive chemotherapy (p < 0.001). A regression analysis determined that HN tumor location and the use of chemotherapy were independent risk factors. CONCLUSIONS: Nutritional status must be monitored and managed before, during and after treatment. A variety of nutritional and tumor-related factors must be considered. According to our results, head and neck tumors and the use of chemotherapy are the only two factors considered statistically significant. Because patients continue to lose weight after treatment, we recommend close surveillance after radiotherapy.

Parkinsonism secondary to metastatic lesions within the central nervous system: a case report.

INTRODUCTION: Colorectal cancer is one of the most common human diseases worldwide, and metastases are detected in approximately 20% of patients at diagnosis. Brain metastases occur in only 4% of cases, however, and usually present with hemiparesis or other motor or sensory symptoms. There have been only a few reports of parkinsonism secondary to a brain tumor-related mass effect. CASE PRESENTATION: We present an unusual case of parkinsonism secondary to multiple brain metastases. A 57-year-old Caucasian man had recently been diagnosed with primary carcinoma of the colon and had multiple metastases in the lungs and liver. He subsequently developed bilateral symmetrical parkinsonism, and multiple brain tumors were detected by computed tomography scanning. The condition of our patient deteriorated rapidly, and he became akinetic and dependent for all activities of daily living. He was followed up and treated at home by our palliative care unit team and died two weeks after the onset of his neurologic symptoms. CONCLUSION: Although primary and secondary brain tumors are uncommon causes of parkinsonism, their clinical presentation may resemble that of idiopathic Parkinson's disease. An awareness of this rare differential diagnosis is therefore important in ensuring early diagnosis and treatment, thus improving prognosis and quality of life. A rapid progression in neurologic symptoms was observed in our patient, and clinicians should be alert to this atypical presentation of secondary parkinsonism.