Quantifying abnormal writing kinematics in writer's cramp using a novel software platform.

BACKGROUND: Writer's cramp is a task-specific focal hand dystonia, which is diagnosed clinically. Quantification of defect in WC is done using clinical scales, while digitized platforms are lacking. OBJECTIVE: To design and test a platform that can differentiate and quantify the abnormal kinematics of writing using a software interface and to validate it in adult-onset isolated writer's cramp (WC). METHODS: A native platform was designed using Java and Wacom Intuos pro tablet and the data analyzed using a MATLAB-based platform called Large Data-Based Evaluation of Kinematics in Handwriting (LEKH). We standardized this new platform by comparing the handwriting between patients with WC and age, and gender and education-matched healthy controls, using standard tasks to assess the kinematics. RESULTS: Comparison of the writing of right-handed WC patients (N = 21) and 39 healthy controls (N = 39) showed that patients differed from controls in the frequency of strokes (P < 0.001), number of inversions of velocity (P < 0.001), number of breaks (P = 0.02), air time and paper time (P < 0.001). CONCLUSIONS: Using the LEKH platform, the kinematic profile of patients with WC could be differentiated from healthy controls. Studies in larger samples will be needed to derive statistical models that can differentiate the flexion and extension types of WC which can help in muscle selection and to quantify the effects of treatment.

An unusual presentation of scleromyxedema as inflammatory myopathy.

Scleromyxedema is a rare cutaneous mucinosis with frequent extracutaneous manifestations. Myopathy in scleromyxedema is a poorly recognized syndrome among neurologists and can mimic idiopathic and connective tissue disease-associated inflammatory myopathy. Diagnosis is suspected by the characterization of the skin lesions and clinched by skin and muscle biopsies. Here, we report a patient with scleromyxedema and myopathy with the characteristic histopathological feature of mucin deposition in skin biopsy. Her muscle biopsy showed a picture consistent with scleromyxedema myopathy with vacuolar and inflammatory changes. The association with paraproteinemia, propensity to life-threatening central nervous system disease and good response to intravenous immunoglobulin necessitate the accurate diagnosis of this condition.