Nociceptive two-point discrimination acuity and body representation failure in polyneuropathy.

OBJECTIVES: Although patients' complaints suggest polyneuropathy (PNP) and neuropathic pain, routine investigations do not always support the diagnosis. Assessing two-point-pain discrimination thresholds (2ptDT) and quantify body representation disturbances might be useful to close this diagnostic gap. METHODS: Pinprick pain and laser-heat pain perception thresholds and 2ptDT on hands, forearms, lower legs and feet were obtained in 20 PNP patients (mean age: 57.6 ± 13.9) and 20 healthy subjects (mean age: 50.6 ± 4.7 years). Body representation disturbances were assessed by self-estimating feet size and the Bath CRPS body perception disturbances questionnaire adapted for PNP. RESULTS: Pain perception thresholds and laser-heat pain 2ptDT were unaltered, but patients had higher pinprick pain 2ptDT then the healthy subjects. The 2ptDT for pinprick at the hands discriminate best between groups (U-test; p=0.001). Furthermore, patients estimated their feet longer than they are. In subsequent multivariate discriminant analyses, 2ptDT for pinprick pain at the hands, 2ptDT for laser-heat pain and the perception thresholds for laser-heat pain at the feet classified 85% of PNP vs. HC correctly. The combination of 2ptDT for pinprick pain at the hands, pinprick pain perception thresholds at the calves and foot length estimation differentiates painful vs. non-painful PNPs correctly in 90% of the cases. CONCLUSIONS: Testing 2ptDT for painful pinprick stimuli at the hands and asking for foot length estimation might add to diagnostic accuracy in painful PNP.

Diagnosis and treatment of Guillain-Barré syndrome during the Zika virus epidemic in Brazil: A national survey study.

The Zika virus (ZIKV) epidemic in Brazil in 2015-2016 was followed by an increase in the incidence of patients with Guillain-Barré syndrome (GBS). With this national survey study, we aimed to gain a better understanding of how neurologists in Brazil are currently diagnosing and treating patients with GBS, and how this increase in incidence has impacted the management of the disease. The questionnaire consisted of 52 questions covering: personal profile of the neurologist, practice of managing GBS during and outside of the ZIKV epidemic, and limitations in managing GBS. All 3264 neurologists that were member of the Brazilian Academy of Neurology at the time of the study were invited to participate. The questionnaire was fully answered by 171 (5%) neurologists. Sixty-one percent of neurologists noticed an increase in patients with GBS during the ZIKV epidemic, and 30% experienced an increase in problems in managing GBS during this time. The most important limitations in the diagnosis and management of GBS included the availability of nerve conduction studies (NCS), beds in the Intensive Care Unit (ICU) and referral to rehabilitation centers. Most neurologists did not use a protocol for treating patients with GBS and the treatment practice varied. Increasing availability of NCS and beds in the ICU and rehabilitation centers, and the implementation of (inter)national guidelines, are critical in supporting Brazilian neurologist in their management of GBS, and are especially important in preparing for future outbreaks.

A non-functional galanin receptor-2 in a multiple sclerosis patient.

Multiple Sclerosis (MS) is an inflammatory neurodegenerative disease that affects approximately 2.5 million people globally. Even though the etiology of MS remains unknown, it is accepted that it involves a combination of genetic alterations and environmental factors. Here, after performing whole exome sequencing, we found a MS patient harboring a rare and homozygous single nucleotide variant (SNV; rs61745847) of the G-protein coupled receptor (GPCR) galanin-receptor 2 (GALR2) that alters an important amino acid in the TM6 molecular toggle switch region (W249L). Nuclear magnetic resonance imaging showed that the hypothalamus (an area rich in GALR2) of this patient exhibited an important volumetric reduction leading to an enlarged third ventricle. Ex vivo experiments with patient-derived blood cells (AKT phosphorylation), as well as studies in recombinant cell lines expressing the human GALR2 (calcium mobilization and NFAT mediated gene transcription), showed that galanin (GAL) was unable to stimulate cell signaling in cells expressing the variant GALR2 allele. Live cell confocal microscopy showed that the GALR2 mutant receptor was primarily localized to intracellular endosomes. We conclude that the W249L SNV is likely to abrogate GAL-mediated signaling through GALR2 due to the spontaneous internalization of this receptor in this patient. Although this homozygous SNV was rare in our MS cohort (1:262 cases), our findings raise the potential importance of impaired neuroregenerative pathways in the pathogenesis of MS, warrant future studies into the relevance of the GAL/GALR2 axis in MS and further suggest the activation of GALR2 as a potential therapeutic route for this disease.

Cross-cultural Adaptation, Reliability, and Validity of the BICAMS in Brazil.

OBJECTIVE: To investigate the reliability and validity of a Brazilian-Portuguese adaptation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS). METHOD: A Brazilian sample of 58 multiple sclerosis (MS) patients and 58 healthy controls (HC) were administered the Brazilian-Portuguese BICAMS test battery, comprising the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test Second Edition (CVLT2), and the Brief Visuospatial Memory Test Revised (BVMTR). Mean differences between groups on BICAMS tests were assessed using analysis of covariance (ANCOVA), controlling for age, gender, education, anxiety, and depression. Test-retest data were obtained from 49 of the MS patients, two weeks after the initial assessment. RESULTS: The MS patient group scored significantly lower on all BICAMS tests (CVLT2 F1,110 = 28.99, p < .001; BVMTR F1,110 = 7.77, p < .01; SDMT F1,110 = 21.09, p < .001). Mixed-factor ANCOVAs tested differences in learning curves across trials for CVLT2 and BVMTR. HCs had significantly steeper learning curves on both CVLT2 (F1,111 = 10.82, p < .01) and BVMTR (F1,110 = 7.816, p < .01). These findings support diagnostic validity of the Brazilian-Portuguese adaptation. Test-retest reliability was satisfactory for SDMT, CVLT2, and BVMTR (.86, .84, and .77, respectively). CONCLUSION: The results suggest that this Brazilian version of the BICAMS will be a valid and reliable measure once complete normative data become available.