A 9-year-old right-handed girl presented with handwriting deterioration and behavioral issues for five months. Initially, she had painful grip tightening and writing difficulty after writing about ten lines, which resolved on resting. After a month, symptoms emerged immediately on writing few words. Symptom fluctuation, weakness, sensory phenomena, ptosis, unresponsiveness, feeding /bladder/bowel/gait abnormalities were absent. Her behavioural problems included unprovoked crying/laughter, auditory hallucinations and tantrums. There was no history of fever, rash, jaundice, head-injury, toxin-exposure, abuse, family history of neurological illnesses. On examination, child’s anthropometry, vital parameters, and systemic examination were normal. After writing 3-4 words, her grip tightened, wrist and interphalangeal joints got flexed, strokes coarsened and slowed, with inability to trace curves. Her left (non-writing) hand had mirror-posturing. Posturing resolved two minutes after discontinuing writing. Percussion myotonia, Trousseau sign and Chvostek’s signs were absent. Child was diagnosed with Writer’s cramp (WC) and psychosis.

Her hemogram, anti-Streptolysin O titer, electro-encephalogram, MRI brain and electromyography were normal. Workup for Wilson disease and autoimmune encephalitis was normal. ESR: 60 mm; Serum antinuclear antibody: strongly positive (speckled); anti double-stranded DNA (dsDNA) titer: 12 IU/mL (reference <5IU/mL); C3 and C4 levels: 30 mg/dL (reference: 80-200 mg/dL) and 12 mg/dL (reference: 15-40 mg/dL), respectively; anti-phospholipid antibodies: absent. She was diagnosed as SLE (European League Against Rheumatism/American College of Rheumatology criteria 2019 score:15) and administered intravenous methyl-prednisolone (30 mg/kg/day × 5 days) followed by maintenance oral prednisolone, hydroxychloroquine, trihexyphenydyl and physiotherapy. Dystonia and behavioural problems reduced significantly in three months.

WC is a rare task-specific limb dystonia reported in fourth fifth decade of life triggered by writing/typing/playing musical instruments and characterized by wrist flexion/extension, dystonic hand posturing, contralateral limb mirror dystonia and sensory trick phenomena [2]. The entity is extremely uncommon in childhood. The prominent differentials include essential tremor, primary writing tremor, neurodegenerative disorders (like Wilson disease), stroke, focal nerve entrapment and musculoskeletal issues [3]. Its patho-physiology is attributed to parietal-premotor pathway dysfunction secondary to etiologies such as genetic factors (e.g,: DYT -1 mutation) and hand trauma [2,4]. It is not reported with SLE. Antibody-mediated phenomena against basal ganglia and frontal lobe probably led to the index child’s symptomatology. Treatments include pharmacological therapy, botulinum-toxin, physiotherapy, neurosurgery and assistive devices [3].

1. Shaban A, Leira EC. Neurological complications in patients with systemic lupus erythematosus. Curr Neurol Neurosci Rep. 2019;19:97.

2. Steeves TD, Day L, Dykeman J, Jette N, Pringsheim T. The prevalence of primary dystonia: a systematic review and meta-analysis. Mov Disord. 2012;27:1789-96.

3. Goldman JG. Writer’s cramp. Toxicon. 2015;10798-104.

4. Amouzandeh A, Grossbach M, Hermsdörfer J, Altenmüller E. Pathophysiology of writer’s cramp: An exploratory study on task-specificity and non-motor symptoms using an extended fine-motor testing battery. J Clin Mov Disord. 2017;4:13.