Long-term efficacy with deep brain stimulation of the globus pallidus internus in cervical dystonia: a retrospective monocentric study

Structural and functional brain alterations in laryngeal dystonia: A coordinate-based activation likelihood estimation meta-analysis

Laryngeal dystonia (LD) is an isolated, task-specific, focal dystonia characterized by intermittent spasms of laryngeal muscles impairing speech production. Although recent studies have demonstrated neural alterations in LD, the consistency of findings across studies is not well-established, limiting their translational applicability. We conducted a systematic literature search to identify studies reporting stereotactic coordinates of peak structural and functional abnormalities in LD patients compared to healthy controls, followed by a coordinate-based activation likelihood estimation meta-analysis. A total of 21 functional and structural neuroimaging studies, including 31 experiments in 521 LD patients and 448 healthy controls, met the study inclusion criteria. The multimodal meta-analysis of these studies identified abnormalities in the bilateral primary motor cortices, the left inferior parietal lobule and striatum, the right insula, and the supplementary motor area in LD patients compared to healthy controls. The meta-analytical findings reinforce the current view of dystonia as a neural network disorder and consolidate evidence for future investigations probing these targets with new therapies.

BDNF-Regulated Modulation of Striatal Circuits and Implications for Parkinson's Disease and Dystonia

Neurotrophins, particularly brain-derived neurotrophic factor (BDNF), act as key regulators of neuronal development, survival, and plasticity. BDNF is necessary for neuronal and functional maintenance in the striatum and the substantia nigra, both structures involved in the pathogenesis of Parkinson's Disease (PD). Depletion of BDNF leads to striatal degeneration and defects in the dendritic arborization of striatal neurons. Activation of tropomyosin receptor kinase B (TrkB) by BDNF is necessary for the induction of long-term potentiation (LTP), a form of synaptic plasticity, in the hippocampus and striatum. PD is characterized by the degeneration of nigrostriatal neurons and altered striatal plasticity has been implicated in the pathophysiology of PD motor symptoms, leading to imbalances in the basal ganglia motor pathways. Given its essential role in promoting neuronal survival and meditating synaptic plasticity in the motor system, BDNF might have an important impact on the pathophysiology of neurodegenerative diseases, such as PD. In this review, we focus on the role of BDNF in corticostriatal plasticity in movement disorders, including PD and dystonia. We discuss the mechanisms of how dopaminergic input modulates BDNF/TrkB signaling at corticostriatal synapses and the involvement of these mechanisms in neuronal function and synaptic plasticity. Evidence for alterations of BDNF and TrkB in PD patients and animal models are reviewed, and the potential of BDNF to act as a therapeutic agent is highlighted. Advancing our understanding of these mechanisms could pave the way toward innovative therapeutic strategies aiming at restoring neuroplasticity and enhancing motor function in these diseases.

Impact of Physiotherapy in the Treatment of Pain in Cervical Dystonia

Background

Cervical dystonia (CD) is the most common form of focal dystonia in adults. Studies show that physiotherapy (PT) in combination with BoNT has an effect on pain in cervical dystonia. We intended to test this hypothesis in a real-world setting to answer the question of whether pain is a good target symptom for prescribing PT. We also aimed to assess which form of PT is most appropriate for the treatment of pain.

Methods

Study design: cross-sectional survey-based study of 91 patients with a confirmed diagnosis of cervical dystonia. The survey consisted of a questionnaire on type, frequency and content of physiotherapy, an assessment of quality of life with the Craniocervical Dystonia Questionnaire 24 (CDQ 24) and subjective pain scores.

Results

53.8% of patients received physiotherapy, mostly a mixture of exercises to either correct the abnormal posture or to reduce the muscle tone. Additional therapies included stress-reducing exercises (14.3%), psychotherapy (9.9%) and EMG biofeedback (2.2%). Patients who received PT showed a non-significant tendency towards higher pain scores. The severity of dystonia-associated pain was significantly associated with the patients' quality of life (F (1,54) = 22.9, adjusted R2 = 0.286, p < 0.001).

Discussion

Pain is a frequent problem in patients with CD and severely affects quality of life. Physiotherapy could therefore be a valuable treatment option for patients with CD and pain.

Highlights

Our uncontrolled study illustrates the high frequency of physiotherapy in addition to BoNT treatment in a real-life cohort of patients with cervical dystonia. We were able to show that PT reduces patients' perceived pain in a patient reported outcome measure. This highlights the importance of PT in reducing CD-related pain, which considerably impairs quality of life.