Stellate Ganglion Blockade for Corticobasal Syndrome Pain: A Case Report and Potential New Discovery.

Abstract

Corticobasal syndrome (CBS) is a neurodegenerative condition characterized by cortical and extrapyramidal dysfunction. It can manifest as painful asymmetric rigidity, spasticity, and dystonia. Treatments include muscle relaxants, analgesics, chemodenervation, and physical therapy.1 Some patient's pain is not alleviated by current treatments, demonstrating the need for new effective treatments. We report what may be the first case of CBS pain treated with stellate ganglion blockade. Stellate ganglion block is used to treat sympathetically mediated pain and complex regional pain syndrome (CRPS) of the upper extremity. We present a 63-year-old female diagnosed with CBS. Six years prior, she developed clumsiness, cramping, and difficulty completing tasks involving the right hand. This progressed to severe right upper extremity rigidity after 2 years. She was evaluated by movement and behavioral neurologists. She exhibited right upper extremity akinesis and rigidity, right sided predominate bradykinesia and leg rigidity, deficits with attention, language and recall, and speech apraxia. Magnetic resonance imaging, positron emission tomography, and dopamine transporter scan revealed volume loss of the left frontal and anterior parietal lobes, hypometabolism in the left posterior frontal region and mid-cingulate regions, and decreased radiotracer binding in the bilateral putamen, greater on the left. Laboratory studies including a frontotemporal dementia panel were unremarkable. As her condition progressed, she began experiencing constant pain in the right upper extremity. It was described as 8 of 10 in severity and only improved with botulinum toxin injections. At best, her pain was 4 of 10 after chemodenervation. However, this benefit often diminished weeks before her next dose. Despite chemodenervation treatment, she continued to describe her pain as “bone-breaking” and “intense.” Her pain did not improve with baclofen, tizanidine, clonazepam, levodopa, fluoxetine, ibuprofen, naproxen, acetaminophen, cannabidiol, topical diclofenac, or physical therapy. She was referred to pain medicine and a sympathetic block was proposed as a palliative measure. A right stellate ganglion block was performed with a 5 mL mixture of 10 mg of dexamethasone and 0.5% bupivacaine with epinephrine 1:200,000. She experienced relief after the procedure and continued to endorse a 0/10 pain at 2.5, 4, and 7 weeks. However, she did not experience improvement in her rigidity, dystonia, or limb akinesia. There has been at least one prior case of a patient with CBS who developed CRPS. Both conditions are associated with bradykinesia, dystonia, immobility, and sensory abnormalities.2 Both exhibit loss of inhibitory input to the cortex, increased cortical excitability,1, 3 and thalamic degeneration.1, 4 CRPS and CBS share the same pain generating mechanism as central post-stroke pain. In each condition, there is sensory deafferentation and reduction in thalamic and sensory input to the cortex, which produces pain.5 There are limited studies on the mechanism of pain generation in CBS. In her case, we suspect it is a combination of both peripherally and centrally mediated processes. The exact explanation for why she benefited from the procedure remains unclear. Sympathetic blockade may be effective in treating CBS-related pain. CBS and CRPS share similar pathophysiologic and phenotypic features. More research is needed to better treat pain associated with CBS and other neurodegenerative disorders. (1) Research project: A. Conception, B. Organization, C. Execution; (2) Statistical Analysis: A. Design, B. Execution, C. Review and Critique; (3) Manuscript: A. Writing of the First Draft, B. Review and Critique. L.H.: 1A, 1B, 1C, 3A. R.F.: 1A, 1C, 3B. E.C.S.: 1C, 3B. Ethical Compliance Statement: The authors confirm that this case is exempt from Institutional Review Board review per University of Nebraska Medical Center policy. Informed consent was discussed verbally with the patient, and then informed consent was obtained in written form. All core elements of Health Insurance Portability and Accountability Act of 1996 (HIPPA) and the additional informed consent requirements of this journal was addressed, obtained, and documented in the patient consent form. The patient consent form can be available upon request. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Funding Sources and Conflicts of Interest: No specific funding was received for this work. The authors declare that there are no conflicts of interest relevant to this work. Financial Disclosures for the Previous 12 Months: The authors declare that there are no additional disclosures to report.