A 31-year-old right-handed male patient with a history of seizures before the age of 3. He noticed right leg stiffness and cramps around the age of 20. Within one year the spasms progressed to the right arm, neck, face, and mandibular muscles. In four years, he developed a soft whispering voice, blepharospasm, and left-sided involvement. Magnetic resonance imaging showed the T2 hyperintensity in the basal ganglia. Gradient echo sequence revealed severe mineralization of bilateral basal ganglia especially GPi and of bilateral medial midbrain in the substantia nigra area. Genetic testing revealed a PANK 2 heterozygous mutation. Despite trials of Carbidopa/Levodopa, Trihexyphenidyl, clonazepam, and Botulinum toxin, the patient had severe disabling blepharospasm, and dystonia in the head, neck, and limbs affecting his gait and causing frequent falls. He underwent DBS placement and was found to have significant GPi calcification, so the neurosurgeon proceeded with the STN as the target for stimulation. 

The patient had significant improvement after the procedure. Nine months after surgery, the Burke-Fahn-Marsden dystonia rating scale dropped from 34 (before the surgery) to 21, with the main improvement in gait and blepharospasm. 

This case highlights the considerable outcome of using STN as a target for DBS placement in patients with PKAN disease. Although not a typical target for dystonia, STN-DBS can provide a substantial benefit in subsiding patients' symptoms and their quality of life.