Transcranial magnetic stimulation (TMS)-based studies have led to an advanced understanding of the pathophysiology of dystonia. This narrative review summarizes the TMS data contributed to the literature so far. Many studies have shown that increased motor cortex excitability, excessive sensorimotor plasticity, and abnormal sensorimotor integration are the core pathophysiological substrates for dystonia. However, an increasing body of evidence supports a more widespread network dysfunction involving many other brain regions. Repetitive TMS pulses (rTMS) in dystonia have therapeutic potential as they can induce local and network-wide effects through modulation of excitability and plasticity. The bulk of rTMS studies has targeted the premotor cortex with some promising results in focal hand dystonia. Some studies have targeted the cerebellum for cervical dystonia and the anterior cingulate cortex for blepharospasm. We believe that therapeutic potential could be leveraged better when rTMS is implemented in conjunction with standard-of-care pharmacological treatments. However, due to several limitations in the studies conducted to date, including small samples, heterogeneous populations, variability in the target sites, and inconsistencies in the study design and control arm, it is hard to draw a definite conclusion. Further studies are warranted to determine optimal targets and protocols yielding the most beneficial outcomes that will translate into meaningful clinical changes.
Keyphrases
- transcranial magnetic stimulation
- high frequency
- deep brain stimulation
- early onset
- case control
- functional connectivity
- healthcare
- resting state
- multiple sclerosis
- palliative care
- systematic review
- artificial intelligence
- quality improvement
- blood brain barrier
- machine learning
- big data
- weight loss
- health insurance
- network analysis
- adipose tissue
- skeletal muscle
- deep learning