Disclosures: Bridget B. Walker, MD: Allergan (Products/Services: Yes) (Research Grant or Support)Medtronic (Products/Services: No) (Research Grant or Support)Merz (Products/Services: No) (Research Grant or Support)Saol Therapeutics (Products/Services: No) (Research Grant or Support)

Case Description: She presented with subacute onset of difficulty walking around age 15 with unclear etiology. Symptoms were primarily right leg heaviness/spasms that progressively worsened over years, worse with walking. Exam was notable for right laterocollis and torticollis with non-rhythmic dystonic tremor. She ambulated with right hip adducted and elevated, knee with increased extension during stance with toe-heel gait and foot inversion. Tone was increased to right hip adductors, bilateral knee extensors, right ankle plantarflexors/invertors. Strength minimally decreased to right > left leg. She previously trialed cyclobenzaprine, baclofen, carbidopa/levodopa, PT, and AFO. No relevant family history. MRI brain and complete spine overall unremarkable.

Setting: Tertiary care hospital

Patient: 38-year-old woman with focal dystonia secondary to novel CACNA1A mutation Assessment/

Results: She had problematic limb and cervical dystonia that caused decreased balance, difficulty with ambulation/stairs, and pain. Neuromuscular specialist ordered genetic testing, which found a novel CACNA1A mutation (calcium-channel gene). Other mutations have been described in episodic ataxia type 2, familial hemiplegic migraine, spinal cerebellar ataxia type 6, paroxysmal torticollis/episodic dystonia. She received onabotulinumtoxin-A to her neck and right lower extremity. Botulinum toxin was reconstituted with 0.9% normal saline to a 100U/2cc concentration for the neck. 60U was divided equally to right splenius capitus, splenius cervicis, and SCM. A 100U/4cc concentration was used for the limb muscles except for medial gastrocnemius, which used a 100U/2cc concentration. A total of 215U was divided into the right vastus intermedius (50U), adductor longus (50U), medial gastrocnemius (40U), and posterior tibialis (75U). EMG and ultrasound were used for guidance. She reported improved ambulation and balance, navigation of stairs, decreased dystonia and pain, with effects lasting for 3 months.

Discussion: This is the first reported case, to our knowledge, of botulinum toxin injections for focal dystonia secondary to CACNA1A mutation.

Conclusion: Botulinum toxin A is an effective treatment for focal dystonia secondary to CACNA1A mutation.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/botulinum-toxin-treatment-for-focal-dystonia-secondary-to-novel-cacna1a-gene-mutation-a-case-report/