Clinical Spectrum of Focal Dystonia in Patients at Tertiary Care Hospital in Karachi: A Cross-Sectional Study

Clinical Patterns of Focal Dystonia

Abstract

Objective: To describe the clinical patterns and types of focal dystonia among patients presenting to the neurology department of a tertiary care hospital in Karachi.

Methodology: This descriptive cross-sectional study was undertaken at Dr. Ruth K. M. Pfau Civil Hospital, a tertiary care institution in Karachi, from 21^st March 2025 to 20th September 2025, including individuals aged 15 to 60 years of both genders. The exclusion criteria included patients with clinical conditions mimicking dystonia (neck extensor myopathy, post-traumatic deformities, Isaacs syndrome, neuromuscular junction disorders, and hemifacial spasm) and non-consenting patients. Following the acquisition of ethical clearance, participants were selected via convenience sampling methodology, with recruitment of consecutive patients presenting with focal dystonia to our department. Comprehensive data regarding demographic characteristics, clinical manifestations, and classification of focal dystonia (blepharospasm, oromandibular dystonia, laryngeal dystonia, cervical dystonia, and limb dystonia) were systematically gathered. Statistical evaluation was conducted utilizing SPSS software, with a significance threshold established at p ≤ 0.05, using the Chi-square test.

Results: There were a total of 75 patients, with a mean age of 32.09 ±11.68 years . Most participants were men (59, 78.7%), while 16 (21.3%) were women. The most frequent form of dystonia involved the neck muscles, causing involuntary twisting of the head (cervical dystonia, 28 patients-37.3%). This was followed by dystonia affecting the arms or legs (limb dystonia, 18 -24.0%), eyelid spasms leading to repeated blinking (blepharospasm, 14 patients -18.7%), voice muscle involvement causing a strained or interrupted voice (laryngeal dystonia, 8 patients 10.7%), and jaw or facial muscle contractions (oromandibular dystonia, 7 patients - 9.3%). Dystonia subtype was strongly connected with both gender (p=0.001) and duration (p=0.050) exhibiting different clinical patterns. Concerning the variability of symptoms, 77.3% experienced persistent dystonia, 10.7% had paroxysmal symptoms, and 12.0% reported diurnal fluctuation.

Conclusions: This study identified cervical dystonia as the most frequent form of focal dystonia, followed by limb dystonia and blepharospasm. Beyond defining subtype distribution, these findings highlight the need for improved awareness and earlier recognition of dystonia among general clinicians to prevent diagnostic delay.