Low Frequency Brain Oscillations during the execution and imagination of simple hand movements for Brain-Computer Interface applications.

Low Frequency Brain Oscillations (LFOs) are brief periods of oscillatory activity in delta and lower theta band that appear at motor cortical areas before and around movement onset. It has been shown that LFO power decreases in post-stroke patients and re-emerges with motor functional recovery. To date, LFOs have not yet been explored during the motor execution (ME) and imagination (MI) of simple hand movements, often used in BCI-supported motor rehabilitation protocols post-stroke. This study aims at analyzing the LFOs during the ME and MI of the finger extension task in a sample of 10 healthy subjects and 2 stroke patients in subacute phase. The results showed that LFO power peaks occur in the preparatory phase of both ME and MI tasks on the sensorimotor channels in healthy subjects and their alterations in stroke patients. Clinical Relevance- Results suggest that LFOs could be explored as biomarker of the motor function recovery in rehabilitative protocols based on the movement imagination.

Cortico-Muscular Coupling Allows to Discriminate Different Types of Hand Movements.

Cortico-muscular coupling (CMC) could be used as potential input of a novel hybrid Brain-Computer Interface (hBCI) for motor re-learning after stroke. Here, we aim of addressing the design of a hBCI able to classify different movement tasks taking into account the interplay between the cerebral and residual or recovered muscular activity involved in a given movement. Hence, we compared the performances of four classification methods based on CMC features to evaluate their ability in discriminating finger extension from grasping movements executed by 17 healthy subjects. We also explored how the variation in the dimensionality of the feature domain would influence the different classifier performances. Results showed that, regardless of the model, few CMC features (up to 10) allow for a successful classification of two different movements type. Moreover, support vector machine classifier with linear kernel showed the best trade-off between performances and system usability (few electrodes). Thus, these results suggest that a hBCI based on brain-muscular interplay holds the potential to enable more informed neural plasticity and functional motor recovery after stroke. Furthermore, this CMC-based BCI could also allow for a more "natural control" (l.e., that resembling physiological control) of prosthetic devices.

Distinctive physiological muscle synergy patterns define the Box and Block Task execution as revealed by electromyographic features.

Stroke survivors experience muscular pattern alterations of the upper limb that decrease their ability to perform daily-living activities. The Box and Block test (BBT) is widely used to assess the unilateral manual dexterity. Although BBT provides insights into functional performance, it returns limited information about the mechanisms contributing to the impaired movement. This study aims at exploring the BBT by means of muscle synergies analysis during the execution of BBT in a sample of 12 healthy participants with their dominant and non-dominant upper limb. Results revealed that: (i) the BBT can be described by 1 or 2 synergies; the number of synergies (ii) does not differ between dominant and non-dominant sides and (iii) varies considering each phase of the task; (iv) the transfer phase requires more synergies. Clinical Relevance- This preliminary study characterizes muscular synergies during the BBT task in order to establish normative patterns that could assist in understanding the neuromuscular demands and support future evaluations of stroke deficits.

[Pemphigus and herpes: Multicentre survey and literature review]. / Pemphigus et herpès : enquête multicentrique et revue de la littérature.

BACKGROUND: Although herpes superinfection is a well-known complication of pemphigus, it has not been widely investigated. AIM: To investigate the frequency and features of herpes infection in patients with ongoing pemphigus. PATIENTS AND METHODS: We carried out a multicenter retrospective study between 2008 and 2016 in patients with newly diagnosed pemphigus presenting active herpes infection. Clinical, virological, immunological and therapeutic data were collated. We performed a literature review for pemphigus and herpes. RESULTS: Among the 191 pemphigus patients, screening for herpes (PCR or culture) was carried out in 11 to 71 % of subjects, depending on the center in question. Twenty-four patients (12 women, mean age 58 years) presented at least one episode of herpes infection. The frequency of positivity ranged from 0 to 42 % by center. Twenty-one cases consisted of pemphigus vulgaris and infection occurred at a mucosal site in 19 patients. Herpes infection was identified at the time of diagnosis in 15 patients and 17 patients received no specific treatment for their pemphigus. The virus was identified using PCR in 23 cases. Ten patients subsequently received prophylactic treatment for herpes. The mean duration of follow-up was 36 months (0-89 months). Thirteen of the 24 patients had 23 relapses of pemphigus; PCR testing for herpes was performed 19 times and was positive in 6 cases (31.5 %). CONCLUSION: Our study showed wide variation in the incidence of herpes superinfection in patients with pemphigus, reflecting the different screening approach at each center (being performed either routinely or only in the event of strong suspicion). The prognostic value of routine screening for herpes in patients with active pemphigus lesions remains to be demonstrated by further prospective investigations.

A fifth subtype of Kaposi's sarcoma, classic Kaposi's sarcoma in men who have sex with men: a cohort study in Paris.

BACKGROUND: Classic Kaposi's sarcoma (CKS) occurs predominantly among elderly men and is associated with Kaposi's sarcoma-associated herpesvirus (KSHV). In low-endemic countries, KSHV infects predominantly men having sex with men (MSM). OBJECTIVES: To describe a cohort of classic Kaposi sarcoma in a low-endemic area for KSHV, to highlight the features of CKS in MSM and identify prognostic factors. METHODS: Retrospective single-centre study of CKS cases. We compared MSM to heterosexual patients. Then, we divided the patients into two subgroups, those requiring a systemic treatment and the others, and we performed univariate and multivariate analyses to determine aggressiveness of CKS. RESULTS: Between 2006 and 2015, seventy-four patients were included. Mean age at diagnosis was 68.9 years; sex ratio (M/F) was 6.4, and 28% were MSM; MSM patients were younger (P = 0.02), less often originated from endemic areas (P < 0.0001). KS was less severe (P = 0.04), required more often a local treatment than a systemic one (P = 0.03). On multivariate analysis, CD4 T-cell count > 500/mm3 at baseline was associated with a reduced risk of severe evolution. CONCLUSION: First CKS cohort in low-endemic zone. We describe a fifth subtype of KS: KS in MSM. The CD4 T-cell count was found to correlate with prognosis.

Pachydermoperiostosis: The value of molecular diagnosis.

BACKGROUND: Pachydermoperiostosis is a rare autosomal recessive genetic disorder characterized by the association of periostosis and pachydermia. To date, two genes involved in prostaglandin metabolism, HPGD and SLCO2A1, have been identified. PATIENTS AND METHODS: A 7-year-old girl presented digital clubbing of the hands and feet, curved nails, hyperhidrosis, and pachydermia, as well as eczema of the trunk and limbs. The diagnosis of pachydermoperiostosis was confirmed by the detection of a homozygous mutation in the HPGD gene. The second case concerned a 41-year-old male with acral and cephalic pachydermia (cutis verticis gyrata), and palmoplantar keratoderma. Bone X-rays showed changes in the distal ends of several bones. The diagnosis of pachydermoperiostosis was confirmed by the detection of a homozygous mutation in the SLCO2A1 gene. DISCUSSION: The genotype/phenotype correlation suggests that patients with SLCO2A1 mutations will develop the symptoms later in life, but that these will be more severe, with a greater likelihood of cutis verticis gyrata and joint involvement compared with patients presenting HPGD mutations. In addition, hereditary enteropathy has recently been described in patients with SLCO2A1 mutations, which could account for the gastrointestinal picture seen in the second patient. Finally, on account of cases involving myelofibrosis associated with mutations in the SLCO2A gene, these patients should have a hematologic follow-up. CONCLUSION: Given the genotype/phenotype correlations illustrated by these cases, it would appear useful to propose molecular diagnosis for patients presenting pachydermoperiostosis.

[Dermatoses and herpes superinfection: A retrospective study of 34 cases]. / Dermatoses et surinfection herpétique : étude rétrospective de 34 cas.

BACKGROUND: Although varicelliform Kaposi eruption is a well-known complication of dermatoses, it has not been widely investigated. AIM: To investigate features of dermatoses and herpes superinfection in patients hospitalized in a dermatology department. PATIENTS AND METHODS: We performed a single-centre, retrospective study between 2008 and 2014 that included cases of Kaposi varicelliform eruptions defined by positive PCR of an unconventional site of herpetic recurrence in a setting of active dermatitis. A record was compiled of each case giving details of the history, clinical and laboratory findings, therapeutic data and outcome. RESULTS: Thirty-four cases of Kaposi varicelliform eruptions in 30 subjects were studied. Mean age at diagnosis was 63.3±24.2 years. The underlying dermatoses were as follows: 7 pemphigus, 6 bullous pemphigoid, 3 cicatricial pemphigoid, 3 atopic dermatitis, 1 Darier disease, and 14 other dermatoses. Patients presented with skin (94.1 %) or mucous membrane lesions (62 %), mostly erosive (79 %), vesicular (27 %) or bullous (41 %), often painful (56 %) or pruritic (29 %). At diagnosis, 41.2 % were undergoing systemic immunotherapy and 24 % were on topical corticosteroids. PCR was positive for HSV1 in 20 cases and for HSV2 in 4 cases, and indeterminate in 10 cases. Lymphocytopenia was seen in 59 % of cases. The majority of patients received treatment. Nine patients experienced at least one relapse. CONCLUSION: Our study confirms the over-representation not only of the expected dermatoses (pemphigus and atopic dermatitis), but also of others such as pemphigoid and acute dermatoses; these results should be investigated in a more systematic prospective study.