Sudoscan as a noninvasive tool to assess sudomotor dysfunction in patients with Fabry disease: results from a case–control study

Pauline Sahuc,1 Laurent Chiche,2 Bertrand Dussol,3 Jean Pouget,1 Jérôme Franques1,2,4 1Department of Neurology, La Timone Hospital, APHM, Aix-Marseille University, 2Department of Internal Medicine, European Hospital, 3Department of Nephrology, La Conception Hospital, APHM, Aix-Marseille University, 4Department of Neurology, La Casamance Hospital, Marseille, France Abstract: Hypohidrosis is a frequent and early symptom in patients with Fabry disease. Studies have reported improved sweating in patients treated with enzyme-replacement therapy. A new method, Sudoscan, has been developed that is noninvasive, is quantitative, and can quickly evaluate sweat gland function. It is based on the electrochemical reaction between sweat chlorides and stainless-steel electrodes in contact with the palms and soles. The aim of our study was to evaluate the Sudoscan as a tool to assess sudomotor dysfunction in patients with Fabry disease. Consecutive patients were prospectively recruited who had a diagnosis of Fabry disease, which had been confirmed genetically and/or by measurement of α-galactosidase activity in leukocytes. Healthy controls, matched (1:1) for age and sex, were also enrolled. Test results were expressed immediately as electrochemical skin conductance (ESC, µS) for hands and feet. Sudomotor dysfunction was considered absent, moderate, or severe if the ESC measured on the feet was >60 µS, between 60 and 40 µS, or <40 µS, respectively. Among the 18 patients, 11 had hypohidrosis or anhidrosis. Hand and feet ESCs were significantly lower in patients compared to their controls (P=0.0015 and P=0.0047, respectively). Among patients, 8/18 (44.5%) had a sudomotor dysfunction, moderate in three and severe in five cases. Hand and feet ESCs were significantly lower in those with hypohidrosis/anhidrosis compared to those without (P=0.0014 and P=0.0056, respectively). This study showed that Sudoscan provided a quick, noninvasive, and quantitative measurement of sudomotor function in Fabry disease patients. Keywords: electrochemical skin conductance, small fiber neuropathy, Fabry disease, sweat dysfunction, hypohidrosi

Primary neurolymphomatosis diagnosis and treatment: A retrospective study

International audienceBackground: To discuss the therapeutic approach for primary neurolymphomatosis. Methods: We report all primary neurolymphomatosis cases referred to our institution, with descriptions of clinical, radiological, electrophysiological, histological features and long-term follow-up. We treated all patients with a combination of high-dose methotrexate and alkylating agents. Results: Five patients were diagnosed with histologically confirmed primary neurolymphomatosis. The majority of them presented with painful asymmetric sensory–motor neuropathy. Magnetic resonance imaging was abnormal in 4 of 5 patients, as shown with gadolinium enhancements. Electroneuromyography revealed denervation in all 4 cases with contributive examinations. All our patients received a chemotherapy combination of high-dose methotrexate and alkylating agent. Median progression-free survival was 8 months (2 complete responses and 2 partial responses), and overall survival was 24 months. Conclusions: Primary neurolymphomatosis is rare and polymorphic; it represents a difficult diagnosis of neuropathy. In our cohort, treatment with a chemotherapy combination with high-dose methotrexate showed encouraging results

Validation of diagnosis criteria for acquired sensory neuronopathy. a francophone multicenter study

Recently published criteria using clinical (ataxia or asymmetrical distribution at onset or full development, and sensory loss not restricted to the lower limbs) and electrophysiological items (less than two abnormal lower limb motor nerves and at least an abolished SAP or three SAP below 30% of lower limit of normal in the upper limbs) were sensitive and specific for the diagnosis of sensory neuronopathy (SNN) (Camdessanche et al., Brain, 2009). However, these criteria need to be validated on a large multicenter population. For this, a database collecting cases from fifteen Reference Centers for Neuromuscular diseases in France and Switzerland is currently developed. So far, data from 120 patients with clinically pure sensory neuropathy have been collected. Cases were classified independently from the evaluated criteria as SNN (53), non-SNN (46) or suspected SNN (21) according to the expert's diagnosis. Using the criteria, SNN was possible in 83% (44/53), 23.9% (11/46) and 71.4% (15/21) of cases, respectively. In the non-SSN group, half of the patients with a diagnosis of possible SSN had an ataxic form of inflammatory demyelinating neuropathy. In the SNN group, half of those not retained as possible SNN had CANOMAD, paraneoplasia, or B12 deficiency. In a second step, after application of the items necessary to reach the level of probable SNN (no biological or electrophysiological abnormalities excluding SNN; presence of onconeural antibody, cisplatin treatment, Sj ¨ ogren's syndrome or spinal cord MRI high signal in the posterior column), a final diagnosis of possible or probable SNN was obtained in, respectively, 90.6% (48/53), 8.8% (4/45), and 71.4% (15/21) of patients in the three groups. Among the 5 patients with a final non-SNN but initial SNN diagnosis, 3 had motor conduction abnormalities (one with CANOMAD) and among the 4 patients with a final SNN but initial non-SSN diagnosis, one had anti-Hu antibody and one was discussed as a possible ataxic CIDP. These preliminary results confirm the sensitivity and specificity of the proposed criteria for the diagnosis of SNN

Motor cortical reorganization is present after a single attack of multiple sclerosis devoid of cortico-spinal dysfunction

International audienceOBJECT: While occurrence of motor cortical reorganization has been clearly demonstrated in patients with multiple sclerosis (MS), it is not yet clear whether this cortical reorganization constitutes a response to cortico-spinal lesions or to more diffuse damage affecting the neuronal network involved in motor act preparation, or both. We proposed to investigate the changes in the activation pattern during a simple motor task devoid of cortico-spinal dysfunction occurring in patients with clinically isolated syndrome (CIS) suggestive of MS. MATERIALS AND METHODS: Among 15 right-handed CIS patients, we selected eight patients with a preserved central motor pathway established by motor evoked potentials. Ten healthy right-handed gender- and age-matched volunteers were also included. After morphological MRI, subjects performed calibrated conjugated finger flexion and extension movements during fMRI acquisition. RESULTS: In CIS patients, simple movements of the non-dominant hand induced recruitment of the anterior cingulate cortex (BA32) usually involved in complex motor movements. This reorganization was correlated with the diffuse brain tissue damage (brain T lesion load). CONCLUSION: These results suggest that at least part of the cortical reorganization observed during very simple tasks in the earliest stage of MS occurs whether or not the efferent pathways are intact