Long-term effects of subthalamic nucleus deep brain stimulation on speech in Parkinson's disease.

Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment in advanced Parkinson's Disease (PD). However, the effects of STN-DBS on speech are still debated, particularly in the long-term follow-up. The objective of this study was to evaluate the long-term effects of bilateral STN-DBS on speech in a cohort of advanced PD patients treated with bilateral STN-DBS. Each patient was assessed before surgery through a neurological evaluation and a perceptual-acoustic analysis of speech and re-assessed in the long-term in different stimulation and drug conditions. The primary outcome was the percentage change of speech intelligibility obtained by comparing the postoperative on-stimulation/off-medication condition with the preoperative off-medication condition. Twenty-five PD patients treated with bilateral STN-DBS with a 5-year follow-up were included. In the long-term, speech intelligibility stayed at the same level as preoperative values when compared with preoperative values. STN-DBS induced a significant acute improvement of speech intelligibility (p < 0.005) in the postoperative assessment when compared to the on-stimulation/off-medication and off-stimulation/off-medication conditions. These results highlight that STN-DBS may handle speech intelligibility even in the long-term.

Interplay between speech and gait variables in Parkinson's disease patients treated with subthalamic nucleus deep brain stimulation: A long-term instrumental assessment.

OBJECTIVE: To evaluate correlations between speech and gait parameters in the long term and under different medication and subthalamic nucleus deep brain stimulation (STN-DBS) conditions in a cohort of advanced Parkinson's disease (PD) patients. METHODS: This observational study included consecutive PD patients treated with bilateral STN-DBS. Axial symptoms were evaluated using a standardized clinical-instrumental approach. Speech and gait were assessed by perceptual and acoustic analyses and by the instrumented Timed Up and Go (iTUG) test, respectively. Disease motor severity was evaluated with the total score and subscores of the Unified Parkinson's Disease Rating Scale (UPDRS) Part III. Different stimulation and drug treatment conditions were assessed: on-stimulation/off-medication, off-stimulation/off-medication, and on-stimulation/on-medication. RESULTS: Twenty-five PD patients with a 5-year median follow-up after surgery (range 3-7 years) were included (18 males; disease duration at surgery: 10.44 [SD 4.62] years; age at surgery: 58.40 [SD 5.73] years). In the off-stimulation/off-medication and on-stimulation/on-medication conditions, patients who spoke louder had also the greater acceleration of the trunk during gait; whereas in the on-stimulation/on-medication condition only, patients with the poorer voice quality were also the worst to perform the sit to stand and gait phases of the iTUG. Conversely, patients with the higher speech rate performed well in the turning and walking phases of the iTUG. CONCLUSIONS: This study underlines the presence of different correlations between treatment effects of speech and gait parameters in PD patients treated with bilateral STN-DBS. This may allow us to better understand the common pathophysiological basis of these alterations and to develop a more specific and tailored rehabilitation approach for axial signs after surgery.

Abnormal eye movements in three types of chorea / Anormalidades dos movimentos oculares em três tipos de coreia

ABSTRACT Chorea is an abnormal movement characterized by a continuous flow of random muscle contractions. This phenomenon has several causes, such as infectious and degenerative processes. Chorea results from basal ganglia dysfunction. As the control of the eye movements is related to the basal ganglia, it is expected, therefore, that is altered in diseases related to chorea. Sydenham’s chorea, Huntington’s disease and neuroacanthocytosis are described in this review as basal ganglia illnesses that can present with abnormal eye movements. Ocular changes resulting from dysfunction of the basal ganglia are apparent in saccade tasks, slow pursuit, setting a target and anti-saccade tasks. The purpose of this article is to review the main characteristics of eye motion in these three forms of chorea.

RESUMO Coreia é um movimento anormal caracterizado pelo fluxo contínuo de contrações musculares ao acaso. Este fenômeno possui variadas causas, como processos infecciosos e degenerativos. A coreia resulta de disfunção dos núcleos da base, os quais estão envolvidos no controle da motricidade ocular. É esperado, então, que esta esteja alterada em doenças com coreia. A coreia de Sydenham, a doença de Huntington e a neuroacantocitose são apresentadas como modelos que têm por característica este distúrbio do movimento, por ocorrência de processos que acometem os núcleos da base. As alterações oculares decorrentes de disfunção dos núcleos da base se manifestam em tarefas de sacadas, perseguição lenta, fixação de um alvo e em tarefas de antissacadas. O objetivo deste artigo é revisar as principais características dos movimentos oculares nestas três formas de coreias.

Stimulation of the pedunculopontine nucleus area in Parkinson's disease: effects on speech and intelligibility.

Improvement of gait disorders following pedunculopontine nucleus area stimulation in patients with Parkinson's disease has previously been reported and led us to propose this surgical treatment to patients who progressively developed severe gait disorders and freezing despite optimal dopaminergic drug treatment and subthalamic nucleus stimulation. The outcome of our prospective study on the first six patients was somewhat mitigated, as freezing of gait and falls related to freezing were improved by low frequency electrical stimulation of the pedunculopontine nucleus area in some, but not all, patients. Here, we report the speech data prospectively collected in these patients with Parkinson's disease. Indeed, because subthalamic nucleus surgery may lead to speech impairment and a worsening of dysarthria in some patients with Parkinson's disease, we felt it was important to precisely examine any possible modulations of speech for a novel target for deep brain stimulation. Our results suggested a trend towards speech degradation related to the pedunculopontine nucleus area surgery (off stimulation) for aero-phonatory control (maximum phonation time), phono-articulatory coordination (oral diadochokinesis) and speech intelligibility. Possibly, the observed speech degradation may also be linked to the clinical characteristics of the group of patients. The influence of pedunculopontine nucleus area stimulation per se was more complex, depending on the nature of the task: it had a deleterious effect on maximum phonation time and oral diadochokinesis, and mixed effects on speech intelligibility. Whereas levodopa intake and subthalamic nucleus stimulation alone had no and positive effects on speech dimensions, respectively, a negative interaction between the two treatments was observed both before and after pedunculopontine nucleus area surgery. This combination effect did not seem to be modulated by pedunculopontine nucleus area stimulation. Although limited in our group of patients, speech impairment following pedunculopontine nucleus area stimulation is a possible outcome that should be considered before undertaking such surgery. Deleterious effects could be dependent on electrode insertion in this brainstem structure, more than on current spread to nearby structures involved in speech control. The effect of deep brain stimulation on speech in patients with Parkinson's disease remains a challenging and exploratory research area.

Treatments for dysarthria in Parkinson's disease.

Dysarthria in Parkinson's disease can be characterised by monotony of pitch and loudness, reduced stress, variable rate, imprecise consonants, and a breathy and harsh voice. Use of levodopa to replenish dopamine concentrations in the striatum seems to improve articulation, voice quality, and pitch variation, although some studies show no change in phonatory parameters. Traditional speech therapy can lead to improvement of dysarthria, and intensive programmes have had substantial beneficial effects on vocal loudness. Unilateral surgical lesions of subcortical structures are variably effective for the alleviation of dysarthria, whereas bilateral procedures typically lead to worsening of speech production. Among deep-brain stimulation procedures, only stimulation of the subthalamic nucleus improves some motor components of speech although intelligibility seems to decrease after surgery. Due to the variable treatment effects on parkinsonian speech, management of dysarthria is still challenging for the clinician and should be discussed with the patient.