Demonstration of a sensory trick in a case of writer's cramp

Writer's cramp

Writer's cramp is the most common form of focal, task-specific dystonia. Symptoms frequently evolve in the setting of repetitive hand movements and increased writing demands, and clinical presentations demonstrate a variety of different dystonic patterns of the upper extremity such as while writing or holding a writing utensil. However, why writer's cramp develops still remains much of a mystery. Clinical evaluation of patients with writer's cramp and various theories regarding its pathophysiology are reviewed. Treatment can be challenging and often involves a combination of pharmacologic (e.g., oral medications, botulinum toxin injections) and non-pharmacologic approaches (e.g., neurosurgical or neurostimulatory interventions, rehabilitation therapies, adaptive devices). Management strategies for writer's cramp using both of these approaches will be discussed.

Tricks in dystonia: ordering the complexity

Sensory tricks are various manoeuvres that can ameliorate dystonia. Common characteristics are well known, but their variety is wide, sensory stimulation is not necessarily the critical feature, and their physiology is unknown. To enumerate the various forms of sensory tricks and describe their nature, research findings and theories that may elucidate their neurophysiologic mechanism, we reviewed the literature pertaining to sensory tricks, including variants like motor tricks, imaginary tricks, forcible tricks and reverse sensory tricks. On the basis of this information, we propose a new classification of sensory tricks to include its variants. We highlight neurophysiologic evidence suggesting that sensory tricks work by decreasing abnormal facilitation. We tie this with established dystonia pathogenesis and postulate that sensory tricks decrease abnormally increased facilitation to inhibition ratios in the dystonic brain. It appears worthwhile for patients to search for possible sensory tricks.