35 research outputs found
Soluble and controlled-release preparations of levodopa: do we really need them?
No full textThe controlled-release preparations of levodopa or newer soluble preparations of levodopa may improve levodopa bioavailability and tolerability and help managing (or even preventing) motor complications. Whether the controlled-release preparations or soluble preparations can really take the place of standard levodopa remains highly controversial, especially in patients receiving chronic levodopa therapy. Controlled-release formulations have a longer half-life and provide more stable plasma levels than standard levodopa. In de novo parkinsonian patients, controlled-release levodopa and standard levodopa are equally efficacious, and carry similar motor complication rates. In patients with advanced disease, whether motor fluctuations respond better to controlled release than to standard oral levodopa remains unclear. In selected parkinsonian patients, single bedtime doses of controlled-release levodopa may improve sleep and nocturnal disability. The poor solubility of levodopa may be overcome by soluble formulations that achieve maximal absorption. A levodopa formulation that guarantees faster and more reliable absorption would be especially useful in the clinical treatment of Parkinson's disease patients experiencing "no-on" or "delayed-on" phenomena. However, further studies with these new formulations are needed to understand if they offer better benefit to parkinsonian patients. New dual formulations incorporating both a faster absorption and an increased half-life than standard levodopa are currently under study. © Springer-Verlag 2010
D’Arcevia o della via al rischio degli arc hetipi, degli arc hivi, dell’arx altissima, dove la lussuria dell’esporre potrebbe condurre a perdersi.
No full textBruno d’Arcevia, pittore, viene ascritto, dai catalogatori di tendenze, ad un gruppo di artisti, chiamati anacronisti. Un gruppo al quale si fanno appartenere anche Carlo Maria Mariani, Di Stasio, Piruca, Omar Galliani.Il motivo sembra essere duplice. Da un lato questo fa riferimento alla capacità di d’Arcevia di interpretare la dimensione mito-immaginaria degli eventi, filtrati e lavorati da una memoria sontuosa, oratoria. Dall’altro non si limita a segnalare – come sembrerebbe volere Calvesi – un ritorno alla pittura dopo le «sperimentazioni pittoriche delle neo-avanguardie», ma prolunga di fatto, ed in senso virtuosistico, una vistosa tradizione accademica, di scuola. Il suo diabolus (in pictura) – come per il referente manierista cinquecentesco – resta sempre rappresentato da un atteggiamento controriformistico, o da letture alla Ludovico Dolce (Dialogo della pittura), o ancor più alla G.B. G.P Bellori : di chi ritenga di dover far ancora scuola alla scuola
Abnormal cortical facilitation and L-dopa-induced dyskinesia in Parkinson's disease
No full textBackground
Animal models of Parkinson's Disease (PD) demonstrated increased facilitatory cortico-striatal activity, reflecting overactive glutamatergic neurotransmission and contributing to the pathophysiology of l-dopa induced dyskinesias (LIDs).
Objective
To assess different facilitatory intracortical circuits in the primary motor cortex (M1) in patients with PD and LIDs by means of a combination of transcranial magnetic stimulation (TMS) protocols.
Methods
We tested the Input/Output (I/O) curve, intracortical facilitation (ICF) and short-interval intracortical facilitation (SICF) at baseline (T0), ‘OFF’ and ‘ON’ state, in 20 PD patients with LIDs. The same parameters were examined after 2 weeks of chronic intake of 50 mg (T1) and 100 mg/day (T2) of safinamide. Finally, we tested SICF in a further group of patients without LIDs.
Results
At T0, patients with LIDs showed increased I/O curve steepness, which was partly ameliorated by l-dopa. These patients also had normal ICF, and abnormally increased SICF, which did not change with l-dopa. Safinamide improved the I/O curve both at T1 and T2, it reduced SICF at T1 and normalized this measure at T2. In patients with PD and LIDs, SICF correlated with the severity of dyskinesia. In patients without LIDs, SICF was less prominently abnormal and responsive to l-dopa.
Conclusions
Patients with PD and LIDs have abnormal cortical facilitation, possibly suggesting overactive glutamatergic neurotransmission in specific circuits within M1. Although not responsive to l-dopa, this dysfunction is restored by the anti-glutamatergic properties of safinamide 100 mg. The results suggest that the abnormal cortical facilitation in M1 contributes to the pathophysiology of LIDs
Effect of camptocormia on lung volumes in Parkinson's disease
No full textCamptocormia is defined as an abnormal flexion of the thoracolumbar spine of 45 degrees, or more, that typically increases during walking or standing and completely disappears in the supine position. Camptocormia may occur in patients with Parkinson's disease; when it does, it is usually associated with greater disease severity. Respiratory complications, which may be secondary to abnormal chest function, are one of the most frequent causes of death in patients with Parkinson's disease. No data on lung volumes are available for Parkinson's disease patients with camptocormia. The aim of this study was to evaluate the effect of camptocormia on lung function. Eleven patients with Parkinson's disease and camptocormia and ten age-matched healthy subjects underwent lung spirometry (in the standing position, inclining the trunk forward at approx. 45 degrees and supine) measurement of arterial oxygen-hemoglobin saturation and heart rate. We found that Parkinson's disease with camptocormia is not associated with major clinical changes in lung volumes. (C) 2013 Elsevier B.V. All rights reserved
Motor training reduces surround inhibition in the motor cortex
Get PDFOBJECTIVE: Surround inhibition (SI) is thought to facilitate focal contraction of a hand muscle by keeping nearby muscles silent. Unexpectedly, SI is reduced in skilled pianists. We tested whether repeated practice of focal contraction in non-pianists could reduce SI. METHODS: Motor-evoked potentials were elicited by transcranial magnetic stimulation in the relaxed abductor digiti minimi randomly at the onset and 5s after offset of a 2s focal contraction (10% maximum) of the first dorsal interosseous (FDI). Over 5 blocks of 40 trials participants obtained points for increasing contraction speed and stability in FDI. In a final block, the interval between contractions was varied randomly to increase attention to the task. RESULTS: Over the first 5 blocks, SI declined as performance (points scored) improved. In the final "attention" block SI increased towards baseline without affecting performance. CONCLUSIONS: Although SI may be useful during the early stages of learning, skilled focal finger movement does not require SI to prevent activity in non-involved muscles. This could be due to better targeting of the excitatory command to move. Results from the final block suggest that increased attention can re-engage SI when task parameters change. SIGNIFICANCE: SI is not necessary for successful focal contraction, but may contribute during learning and during attention to task
Somatosensory temporal discrimination tested in patients receiving botulinum toxin injection for cervical dystonia
No full textWe designed this study to find out more about the relationship between the sensory effects of Botulinum toxin type A (BTX) and the clinical benefits of BTX therapy in patients with cervical dystonia (CD). In 24 patients with CD, we tested sensory temporal discrimination (STD) in the affected and two unaffected body regions (neck, hand, and eye) before and 1 month after BTX injection. In 8 out of the 24 patients with CD, STDT values were tested bilaterally in the three body regions before, 1 and 2 months after BTX injection. As expected, STD testing disclosed altered STD threshold values in all three body regions tested (affected and unaffected by dystonic spasms) in patients with CD. STD threshold values remained unchanged at all time points of the follow-up in all CD patients. The lack of BTX-induced effects on STD thresholds suggests that STD recruits neural structures uninvolved in muscle spindle afferent activation. (C) 2010 Movement Disorder Societ
Abnormal motor cortex excitability during linguistic tasks in adductor-type spasmodic dysphonia
No full textIn healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal
