Research Bits

New dystonia studies are published daily. Below are a tiny sample of recent data and discoveries.

PLAN B.

TorsinA is a protein found in neurons (brain cells) that causes dystonia when it becomes abnormal due to small genetic changes. When TorsinA is abnormal, it cannot function properly in the cell. This loss of function ultimately leads to the development of dystonia symptoms. A related protein, called TorsinB, performs similar roles in neurons as TorsinA. A team of investigators recently demonstrated in mice that dystonia symptoms and related neuron dysfunction resulting from a loss of function of TorsinA can be corrected by increasing levels of TorsinB. These findings suggest that TorsinB may be mobilized to slow or prevent the development of dystonia symptoms.

Li J, Liang CC, Pappas SS, Dauer WT. TorsinB overexpression prevents abnormal twisting in DYT1 dystonia mouse models. Elife. 2020;9:e54285. Published 2020 Mar 23.

DYSTONIA GENES & MENTAL HEALTH.

There are many types of dystonia, often presenting with very distinct symptoms. There is also a great deal of overlap in the physical manifestation of symptoms across the different types. Non-motor symptoms are common, including psychiatric disorders such as depression and anxiety. There have been numerous genes identified to cause dystonia, and it is not yet clear what these genes have in common. A group of researchers set out to help disentangle the complex genetic landscape of dystonia by systematically analyzing genetic data from mice and humans. They set out to learn whether dystonia-causing genes can be linked to shared brain pathways and, if so, where in the brain this convergence takes place. Plus, whether there are underlying genetic links to the psychiatric disorders frequently seen in dystonia. Using new and well-established genetic approaches, the researchers tested 28 dystonia genes for increased expression in specific brain cell types. They found that multiple dystonia-causing genes interact and contribute to dysfunctional signaling in specific groups of neurons in the brain. Furthermore, commonalities have been found in the underlying genetic basis of dystonia and a range of psychiatric disorders often seen in dystonia patients including anxiety, depression, and obsessive-compulsive disorder. These findings suggest that certain mental health disorders may be part of the underlying genetics of dystonia, thereby increasing an individual’s risk of developing psychiatric symptoms. The report reflects the increasing call from experts to recognize and address non-movement symptoms in dystonia patients. The results also represent an important step in better understanding the brain pathways involved in dystonia and examining relationships among dystonia-causing genes and among dystonia types.

Mencacci NE, Reynolds R, Ruiz SG, et al. Dystonia genes functionally converge in specific neurons and share neurobiology with psychiatric disorders. Brain. 2020;143(9):2771-2787 Busch H, Klein C. ‘Moving genes’: how dystonia genes functionally converge on the transcriptome. Brain. 2020 Sep 1;143(9):2631-2634.

DRIVER’S ED.

A research team in the Netherlands set out to explore driving performance and driving safety in individuals with cervical dystonia compared to individuals without cervical dystonia. All participants in the cervical dystonia group participated in the study 4-8 weeks after botulinum neurotoxin treatment, which tends to be the time of maximum benefit. Volunteers completed a simulated driving assessment that included lane tracking, intersections, and highway merging. In the individuals with cervical dystonia, there was no indications that driving performance or safety were significantly different than the group without cervical dystonia. However, cervical dystonia patients notably reported higher levels of fatigue before and after driving.

Van den Dool J, Visser B, Huitema RB, Caljouw SR, Tijssen MAJ. Driving Performance in Patients With Idiopathic Cervical Dystonia; A Driving Simulator Pilot Study. Front Neurol. 2020;11:229.

Republished, with permission from DMRF Dystonia Dialogue, Winter 2020 Vol 43, No 3.