Deep brain stimulation improves quality of life in pantothenate kinase-associated neurodegeneration
A 10-year-old girl born of non-consanguineous marriage was apparently well up to 2.5 years of age with the normal development. Thereafter, she developed frequent falls while walking without any visual disturbances and had mild slurring of speech. At this time, she had normal hearing and cognition. Physical examination revealed unsteady gait with mild dystonia in all extremities along with mild dysarthria with normal sensory and cranial nerve examination. Metabolic work-up was normal. Brain MRI revealed classical “eye of tiger” appearance (fluid attenuated inversion recovery sequence {FLAIR}) hyperintensities in bilateral globus pallidi with surrounding hypointensity). Diagnosis of Halloverdan Spatz disease (PKAN) was confirmed as PANK2 gene deletion testing was positive. Medical management comprising of trihexiphenidyl, baclofen, clonazepam, L-dopa, and botulinum toxin was tried with little therapeutic success in arresting the symptom progression. Over the ensuing years, there was gradual worsening in her mobility and ability to do activities of daily living. She developed severe generalized dystonia affecting her limbs, trunk, face, and tongue causing difficulty in walking, dressing, use of hands, difficulty in opening eyes due to severe blepharospasm and problems with chewing, deglutition, vocalization, and maintaining hygiene. She required gastrostomy tube feeding to maintain nutrition. She was totally wheel chair bound for mobility by 7 years of age. At the age of 9 years, she had severe dystonic spasms and marked discomfort from dystonia. She was offered DBS surgery at this stage. Pre-DBS assessment denoted “Burke-Fahn-Marsden (BFM) Dystonia Rating Scale Motor Score” 120/120 and “BFM Dystonia Rating Scale Disability Score” 28/29 implying severe generalized dystonia and severe difficulty in activities of daily living respectively. There was a definite improvement in the dystonia post-operatively, which was sustained even at 15 months post-DBS. The BFM Dystonia Rating Scale Motor Score improved to 42.5/120 while BFM dystonia Rating Scale Disability Score improved to 25/29. This was reflected in her ability to sit in a chair, stand and walk few steps with support, opening eyes and ease in chewing and swallowing food. However, there was no improvement in the speech yet.