Prime mover muscle in finger lift or finger flexion reaction times: identification with transcranial magnetic stimulation.

When recording the onset of the electromyographic (EMG) voluntary response in reaction time (RT) studies, the electrodes should be placed on the muscle which is first and foremost involved in executing the response. It is thus necessary to identify which is the prime mover muscle among active synergic muscles. This has been investigated for index finger lift or flexion RTs by delivering a magnetic stimulus to motor cortical areas prior to the subject's voluntary response. The EMG responses to the magnetic stimulus were selectively facilitated either in the extensor indicis proprius muscle (in index lift RTs) or in the first dorsal interosseous muscle (in index flexion RTs). These effects are robust and provide a method for identifying the prime mover muscle in voluntary movements.     

Delayed increase in infarct volume after cerebral ischemia: correlations with thrombolytic treatment and clinical outcome

BACKGROUND AND PURPOSE: Growing experimental evidence indicates that the development of cerebral ischemic damage is slower than previously believed. The aims of this work were (1) to study the evolution of CT hypoattenuation between 24 to 36 hours and 7 days in ischemic stroke patients; (2) to evaluate whether thrombolytic treatment given within 6 hours of stroke affects delayed infarction evolution; and (3) to investigate possible correlations between lesion volume changes over time and clinical outcome. METHODS: Of 620 patients included in the European Cooperative Acute Stroke Study 1 (ECASS1), we selected 450 patients whose control CT scans at day 1 (CT1) and day 7 (CT7) were available. They had been randomly divided into 2 groups: 206 patients had been treated with rtPA and 244 with placebo. CT1 and CT7 were classified according to the location of the infarct. The volume of CT hypoattenuation was measured using the formula AxBxC/2 for irregular volumes. The 95% confidence interval of inter- and intrarater variability was used to determine whether significant changes in lesion volume had occurred between CT1 and CT7. Clinical severity was evaluated by means of the Scandinavian Stroke Scale (SSS) at entry (SSS0) and at day 30 (SSS30). RESULTS: Mean lesion volumes were significantly (P<0.0001) higher at day 7 than at day 1 in all the subgroups of patients and particularly in patients with a subcortical lesion. Of the 450 patients studied, 287 (64%) did not show any significant change in lesion volume between CT1 and CT7, 143 (32%) showed a significant increase and the remaining 20 (4%) a significant decrease. No significant correlation was observed between treatment and lesion evolution between CT1 and CT7. Both clinical scores (SSS0 and SSS30) and degree of neurological recovery were significantly (P<0.05) lower in the subgroup of patients with a significant lesion volume increase than in the other 2 groups. CONCLUSIONS: In approximately two thirds of patients, infarct size is established 24 to 36 hours after stroke onset, whereas in the remaining one third, changes in lesion volume may occur later than the first 24 to 36 hours. Many factors may be responsible for delayed infarct enlargement and for a lower degree of clinical recovery, both of which may occur despite early recombinant tissue plasminogen activator treatment.     

Thalamo-cortical networks in subtypes of migraine with aura patients

BackgroundWe searched for differences in resting-state functional connectivity (FC) between brain networks and its relationship with the microstructure of the thalamus between migraine with pure visual auras (MA), and migraine with complex neurological auras (MA+), i.e. with the addition of at least one of sensory or language symptom.Methods3T MRI data were obtained from 20 patients with MA and 15 with MA + and compared with those from 19 healthy controls (HCs). We collected resting state data among independent component networks. Diffusivity metrics of bilateral thalami were calculated and correlated with resting state ICs-Z-scores.ResultsAs compared to HCs, both patients with MA and MA + disclosed disrupted FC between the default mode network (DMN) and the right dorsal attention system (DAS). The MA + subgroup had lower microstructural metrics than both HCs and the MA subgroup, which correlated negatively with the strength of DMN connectivity. Although the microstructural metrics of MA patients did not differ from those of HCs, these patients lacked the correlation with the strength of DAS connectivity found in HCs.ConclusionsThe present findings suggest that, as far as MRI profiles are concerned, the two clinical phenotypes of migraine with aura have both common and distinct morpho-functional features of nodes in the thalamo-cortical network.     

Efficient recovery of fluoroquinolone-susceptible and fluoroquinolone-resistant Escherichia coli strains from frozen samples.

We assessed the rate of recovery of fluoroquinolone-resistant and fluoroquinolone-susceptible Escherichia coli isolates from culture of frozen perirectal swab samples compared with the results for culture of the same specimen before freezing. Recovery rates for these 2 classes of E. coli were 91% and 83%, respectively. The majority of distinct strains recovered from the initial sample were also recovered from the frozen sample. The strains that were not recovered were typically present only in low numbers in the initial sample. These findings emphasize the utility of frozen surveillance samples.     

Monthly brain magnetic resonance imaging scans in patients with clinically isolated syndrome

We investigated if monthly gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) can assist the clinician in anticipating the diagnosis of multiple sclerosis (MS) in the very first few months following a clinically isolated syndrome (CIS). A consecutive series of CIS patients with > or = 3 T2-weighted (T2W) hyperintense brain MRI lesions suggestive of MS were followed up for the first six consecutive months after enrollment with monthly triple-dose Gd-enhanced brain MRI scan. MRI conversion to MS was defined by the presence of either > or = 1 new Gd-enhancing lesion or > or = 1 new T2W lesions in the subsequent MRI scan. Sixty patients were included. Of them, 30 (50%) had at least one Gd-enhancing lesion on the baseline MRI scan. After three months, MRI conversion to MS was observed in 80% and 62% of patients based on the appearance of > or = 1 new T2 lesion and > or = 1 new Gd-enhancing lesions, respectively. The presence of > or = 1 new T2W lesion was observed in 90% and 82% of patients who had, at baseline, a Gd-positive MRI scan and dissemination in space based on the new McDonald's criteria, respectively The rate of MRI conversion remained almost stable in the last two MRI scans. Our study suggests that the majority of CIS patients with an abnormal baseline scan showed an MRI conversion to MS after three months. The model of six months as the optimal interval for repeating MRI exam is not supported by the present data.     

Uric acid, phosphate and oxalate stones: treatment and prophylaxis

Medical treatment for the most commonly encountered types of renal stones is described. Nowadays treatment for uric acid stones is well-defined: alkalinizing urine is easy with drugs that are sufficiently active and well enough managed. Relapse is avoided in a high percentage of patients. Medical treatment of phosphate or calcium stones is a more open question as results are far from satisfactory compared with intra- and extra-corporeal approaches which are often minimally invasive and well accepted by both patient and urologist. Relapses are not easy to control because prophylactic measures such as changes in lifestyle and diet are never activated or because they are adopted for a brief period of time. Water therapy is examined, with the choice of water depending on the type of stone, together with drug therapy. Drugs such as citrate, with or without magnesium, and thiazides are considered excellent for curing renal stones and relapses. Although medical therapy has a limited role in many types of stones, its use is decisive in some others.