Tonic spinal cord stimulation as therapeutic option in Parkinson disease with axial symptoms: Effects on walking and quality of life.

Spinal cord stimulation (SCS) is an effective surgical therapy used for the treatment of chronic neuropathic pain. Tonic SCS is safe and improve not only gait disorders, motor symptoms, but also quality of life in Parkinson patients even with dopa-resistant symptoms with or without associated deep brain stimulation.

Abnormal cerebellar processing of the neck proprioceptive information drives dysfunctions in cervical dystonia.

The cerebellum can influence the responsiveness of the primary motor cortex (M1) to undergo spike timing-dependent plastic changes through a complex mechanism involving multiple relays in the cerebello-thalamo-cortical pathway. Previous TMS studies showed that cerebellar cortex excitation can block the increase in M1 excitability induced by a paired-associative stimulation (PAS), while cerebellar cortex inhibition would enhance it. Since cerebellum is known to be affected in many types of dystonia, this bidirectional modulation was assessed in 22 patients with cervical dystonia and 23 healthy controls. Exactly opposite effects were found in patients: cerebellar inhibition suppressed the effects of PAS, while cerebellar excitation enhanced them. Another experiment comparing healthy subjects maintaining the head straight with subjects maintaining the head turned as the patients found that turning the head is enough to invert the cerebellar modulation of M1 plasticity. A third control experiment in healthy subjects showed that proprioceptive perturbation of the sterno-cleido-mastoid muscle had the same effects as turning the head. We discuss these finding in the light of the recent model of a mesencephalic head integrator. We also suggest that abnormal cerebellar processing of the neck proprioceptive information drives dysfunctions of the integrator in cervical dystonia.

"De-novo" consultation: Evaluation of an outpatient's clinic dedicated to early diagnosis of parkinsonian syndromes.

INTRODUCTION: In the absence of specific clinical signs, imaging or biomarkers, the differential diagnosis of degenerative parkinsonian syndromes may be difficult at early stages of the disease. To reduce the risk of misdiagnosis or delayed diagnosis and referral to multiple medical centers at disease onset, easier access to expert centers should be available. To improve the initial care of parkinsonian patients, the Parkinson's disease Expert Center (PEC) at Pitié-Salpêtrière Academic Hospital has set up a specific outpatients clinic with short waiting times dedicated to the diagnosis of early Parkinson's disease and related disorders. METHODS: The PEC setup first identifies requests for diagnostic confirmation of parkinsonian syndromes, then specific outpatients clinic visits are scheduled weekly, with examinations carried out by neurologists at the PEC on a rotating schedule. Data from the first year of the new procedure were analyzed retrospectively through self-administered questionnaires sent to patients seen during this period. The main outcomes were to confirm the ability to keep to short delays for patients' examinations and to assess patients' satisfaction with the setup. RESULTS: Both study outcomes were achieved. The creation of an outpatients clinic dedicated to the early diagnosis of parkinsonian syndromes allowed shorter delays before the first examination of 5 weeks instead of several months. Keeping to the weekly schedule and limited time taken for each visit was also achieved. Following this initial outpatients visit, diagnosis of a parkinsonian syndrome was clinically confirmed or further specified in 80% of cases. A survey of patients' satisfaction showed a rate of over 91% in terms of the timing and course of clinical examinations at our PEC. DISCUSSION/CONCLUSION: This study of our quality-improvement program for Parkinson's disease management has shown that specific consultations with shorter waiting times aiming to allow early specialized assessment of parkinsonian syndromes is beneficial for patients and reduces the risk of delayed diagnoses.

Protection of yttria-stabilized zirconia for dental applications by oxidic PVD coating.

In this study, the application of transparent physical vapor deposition (PVD) coatings on zirconia ceramics was examined as an approach to retard the low-temperature degradation of zirconia for dental applications. Transparent monolayers of titanium oxide (TixOy) and multilayers consisting of titanium oxide-alumina-titanium oxide (TixOy-AlxOy-TixOy) were deposited onto standardized discs of 3Y-TZP using magnetron sputtering. Using X-ray photospectroscopy and time-of-flight secondary-ion mass spectrometry, the compositions of the coatings were verified, and an approximate thickness of 50 nm for each type of coating was ascertained. After aging the coated and uncoated samples in water vapor at 134°C and 3 bar for 4, 8, 16, 32, 64 and 128 h, the monoclinic phase content was determined using X-ray diffraction, and its impact on mechanical properties was assessed in biaxial flexural strength tests. In addition, the depth of the transformation zone was measured from scanning electron microscopy images of the fracture surfaces of hydrothermally aged samples. The results revealed that the tetragonal-to-monoclinic phase transformation of the zirconia ceramic was retarded by the application of PVD coatings. During the first stages of aging, the coated samples exhibited a significantly lower monoclinic phase content than the uncoated samples and, after 128 h of aging, showed a transformation zone which was only ∼12-15 µm thick compared to ∼30 µm in the control group. Biaxial flexural strength decreased by ∼10% during aging and was not influenced by the application of a PVD coating.

Cerebellar processing of sensory inputs primes motor cortex plasticity.

Plasticity of the human primary motor cortex (M1) has a critical role in motor control and learning. The cerebellum facilitates these functions using sensory feedback. We investigated whether cerebellar processing of sensory afferent information influences the plasticity of the primary motor cortex (M1). Theta-burst stimulation protocols (TBS), both excitatory and inhibitory, were used to modulate the excitability of the posterior cerebellar cortex and to condition an ongoing M1 plasticity. M1 plasticity was subsequently induced in 2 different ways: by paired associative stimulation (PAS) involving sensory processing and TBS that exclusively involves intracortical circuits of M1. Cerebellar excitation attenuated the PAS-induced M1 plasticity, whereas cerebellar inhibition enhanced and prolonged it. Furthermore, cerebellar inhibition abolished the topography-specific response of PAS-induced M1 plasticity, with the effects spreading to adjacent motor maps. Conversely, cerebellar excitation had no effect on the TBS-induced M1 plasticity. This demonstrates the key role of the cerebellum in priming M1 plasticity, and we propose that it is likely to occur at the thalamic or olivo-dentate nuclear level by influencing the sensory processing. We suggest that such a cerebellar priming of M1 plasticity could shape the impending motor command by favoring or inhibiting the recruitment of several muscle representations.

Psychogenic nonepileptic seizures: characterization of two distinct patient profiles on the basis of trauma history.

This prospective study investigated and compared psychiatric features of 25 consecutive patients with psychogenic nonepileptic seizures (PNES) on the basis of presence of reported trauma. The "trauma" group comprised 19 patients (76%) and the "no-trauma" group comprised 6 patients (34%). We compared history of PNES, psychiatric comorbidity, alexithymia, and symptoms of dissociation. The study clearly characterized two distinct profiles of patients with PNES on the basis of trauma history. Patients with trauma had at least one psychiatric comorbidity or antecedent (vs 0% in the no-trauma group NT, P<0.001) and a higher median score of dissociation (P<0.001). Patients without trauma had more frequent "frustration situations" as a factor triggering PNES and subsequent sick leaves as perpetuating factors (P=0.001). Trauma antecedents correlated with a high rate of psychiatric comorbidity and a strong dissociative mechanism. Patients without trauma had no psychiatric comorbidity and a weaker dissociative mechanism.

[Psychogenic non epileptic seizures: a review]. / Crises psychogènes non épileptiques. Revue de la littérature.

OBJECTIVE: This paper summarizes the recent literature on the phenomena of psychogenic non epileptic seizures (PNES). DEFINITION AND EPIDEMIOLOGY: PNES are, as altered movement, sensation or experience, similar to epilepsy, but caused by a psychological process. Although in the ICD-10, PNES belong to the group of dissociative disorders, they are classified as somatoform disorders in the DSM-IV. That represents a challenging diagnosis: the mean latency between manifestations and diagnosis remains as long as 7 years. It has been estimated that between 10 and 30% of patients referred to epilepsy centers have paroxysmal events that despite looking like epileptic episodes are in fact non-epileptic. Many pseudo epileptic seizures have received the wrong diagnosis of epilepsy being treated with anticonvulsants. The prevalence of epilepsy in PNES patients is higher than in the general population and epilepsy may be a risk factor for PNES. It has been considered that 65 to 80% of PNES patients are young females but a new old men subgroup has been recently described. POSITIVE DIAGNOSIS AND PSYCHIATRIC COMORBIDITIES: Even if clinical characteristics of seizures were defined as important in the diagnosis algorithm, this point of view could be inadequate because of its lack of sensitivity. Because neuron-specific enolase, prolactin and creatine kinase are not reliable and able to validate the diagnosis, video electroencephalography monitoring (with or without provocative techniques) is currently the gold standard for the differential diagnosis of ES, and PNES patients with pseudoseizures have high rates of psychiatric disorders such as depression, anxiety, somatoform symptoms, dissociative disorders and post-traumatic stress disorder. We found evidence for correlations between childhood trauma, history of childhood abuse, PTSD, and PNES diagnoses. PNES could also be hypothesized of a dissociative phenomena generated by childhood trauma. PATHOPHYSIOLOGY: Some authors report that PNES can be associated with a physical brain disorder playing a role in their development: head injury may contribute to the pathogenesis of PNES. New-onset psychogenic seizures after resective epilepsy surgery or other intracranial neurosurgery have been described. Recent studies found psychogenic seizure disorders associated with brain pathology in the right hemisphere, non specific interictal electroencephalography abnormalities, magnetic resonance imaging changes and neuropsychological deficits. However, complex partial seizures of frontal origin might present similar characteristics with PNES and could be confused with the latter. PROGNOSIS AND TREATMENT: There is actually no clear agreement as the best treatment plan for PNES patients. The PNES diagnosis has to be clearly communicated to the patient. Nevertheless, even after a correct diagnosis is made a high proportion of PNES patients continue to have seizures, serious disability and bad self-reported quality of life. Furthermore, seizure remission cannot be considered a comprehensive measure of medical or psychosocial outcome. Nearly half of the patients who become seizure free remain unproductive and many of these patients continue to have symptoms of psychopathology including other somatoform, depressive, and anxiety disorders. Even if psychiatric comorbidities have to be treated by a psychiatrist? who could also suggest a psychotherapy, in all cases the importance of a neurologist continuing to follow post-diagnosis PNES patients is essential. CONCLUSIONS: PNES is a diagnostic and therapeutic challenge that is costly to patients and to society at large. Further studies are needed to understand this dissociative psychiatric disorder and to propose therapeutic guidelines.

Development of a high resolution and high dispersion Thomson parabola.

Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE∕E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon.

A novel DCC mutation and genetic heterogeneity in congenital mirror movements.

OBJECTIVE: DCC is the receptor for netrin, a protein that guides axon migration of developing neurons across the body's midline. Mutations in the DCC gene were recently identified in 2 families with congenital mirror movements (MM). The objective was to study clinical and genetic characteristics of 3 European families with MM and to test whether this disorder is genetically homogeneous. METHODS: We studied 3 MM families with a total of 13 affected subjects. Each patient had a standardized interview and neurologic examination, focusing on the phenomenology and course of the MM. The severity of MM was also assessed. Molecular analysis of DCC was performed in the index cases. In addition, linkage analysis of the DCC locus was performed in a large French family. RESULTS: The clinical expression and course of MM were very similar in all the affected subjects, regardless of DCC mutational status. However, slight intersubject variability in the severity of MM was noted within each family. Onset always occurred in infancy or early childhood, and MM did not deteriorate over time. Motor disability due to MM was mild and restricted to activities that require independent movements of the 2 hands. We found a novel mutation in the DCC gene in an Italian family with MM associated with abnormal ipsilateral corticospinal projection. The DCC locus was excluded in the French family. CONCLUSION: DCC has a crucial role in the development of corticospinal tracts in humans. Congenital MM is genetically heterogeneous, despite its clinical homogeneity.

[Risk of epilepsy after a first epileptic seizure in adults: Can we predict the future?]. / Prise en charge d'une première crise épileptique de l'adulte : peut-on prévoir l'avenir ?

The new definition of epilepsy recently proposed by an international panel of experts relies on the association of a first clinically certain seizure and of an enduring predisposition of the brain increasing the likelihood of future seizures. In the first part of this review, we will expose and organize into a hierarchical order the risk factors of subsequent recurrence. The major factors are: seizure(s) prior to presentation, paroxysmal abnormalities on early EEG, a remote symptomatic etiology. In the second part of this review, we will address the issue of clinical uncertainty when assessing the epileptic origin of a first clinical paroxysmal event, the reasons of uncertainty and the means to minimize it. We will analyze successively: the accuracy of eyewitness observations of transient loss of consciousness, the reliability and predictive validity of clinical criteria used for seizure assessment, the issue of overlapping clinical features between seizure and other non epileptic paroxysmal events (such as psychogenic non epileptic seizures), and finally the reliability and diagnostic value of early EEG for seizure assessment. To conclude, seizure assessment and diagnosis of epilepsy cannot be dissociated from syndrome and etiology diagnosis, which should be periodically reassessed towards a greater accuracy during the course of the disease.

Erythrocyte osmotic fragility and cation concentrations during experimentally induced bovine anaplasmosis.

1. The osmotic fragility, the concentrations of Na, K and Ca, the osmolality and the total ATPase activity of bovine erythrocytes from uninfected and Anaplasma marginale-infected bovines were studied in an attempt to correlate these parameters with the decrease in the cellular ATP concentration reported during bovine anaplasmosis. 2. The osmotic fragility found in infected bovine erythrocytes, at 0.52% NaCl, was about two times greater than that observed in non-infected bovines. The increase in osmotic fragility was directly related to the increase in intra-erythrocytic parasitemia. 3. The decrease in ATP concentration reported during bovine anaplasmosis could not be directly related to the increased fragility of these cells. The artificial depletion of erythrocytic ATP did not reproduce the same alteration in the osmotic response to NaCl. 4. The plasmatic and cytoplasmatic concentrations of Na, K and CA did not change significantly during bovine anaplasmosis, whereas the interior of the erythrocytes became hyperosmolal. 5. A. marginale-infected bovine erythrocyte membranes showed an increased ATPase activity when compared to control bovines. Parasite-enriched fractions also presented ATPase activity.