Chou Claudia Z, Ahlskog J Eric, Klassen Bryan T, Coon Elizabeth A, Ali Farwa, Bower James H, Savica Rodolfo, Hassan Anhar
Division of Community Internal Medicine, Geriatrics, and Palliative Care, Mayo Clinic, 200 First St SW, Rochester, MN 59905, USA.
Department of Neurology, Mayo Clinic, 200 First St SW, Rochester, MN 59905, USA.
Clin Park Relat Disord. 2022 Jun 16;7:100149. doi: 10.1016/j.prdoa.2022.100149. eCollection 2022.
Patients with functional tremor may be clinically misdiagnosed as "medication-refractory" essential tremor (ET) and referred for surgical treatment. Electrophysiology can screen for functional tremor and avoid inappropriate surgery.
To report the utility of surface electrophysiology (SEMG) to screen for functional tremor in patients referred for ET surgery.
Retrospective review of consecutive ET patients referred to the Mayo Clinic DBS clinic over 1.5 years. Included subjects had a clinical diagnosis of medication-refractory ET and completed presurgical workup including routine SEMG tremor study.
Of 87 subjects, 9 (10%) were clinically suspected of functional tremor by the DBS neurologist. Electrophysiology confirmed functional tremor features in 7/9 and ET in the other 2/9; and newly identified 5 additional cases of functional tremor. There were 12 total confirmed cases of functional tremor: isolated in 1, and mixed functional tremor and ET in 11. Of 11 mixed patients, 6 with mild functional overlay were approved for surgery. The remaining 5 patients with moderate-severe functional overlay and the single patient with isolated functional tremor were referred to the functional tremor motor retraining program. Of these, 1 patient with mixed tremor had residual disabling organic ET after program completion and was later approved for surgery. Thus, 5/87 patients (6%) avoided unnecessary surgery.
Functional tremor may frequently overlay "medication-refractory" ET amongst patients referred for surgery, affecting 1 of 7 patients in our quaternary referral DBS center. Electrophysiology studies are useful to routinely screen patients and prevent unnecessary surgery.
功能性震颤患者临床上可能被误诊为“药物难治性”特发性震颤（ET）并被转诊接受手术治疗。电生理学可筛查功能性震颤并避免不适当的手术。
报告表面肌电图（SEMG）在转诊接受ET手术的患者中筛查功能性震颤的效用。
回顾性分析在1.5年期间转诊至梅奥诊所DBS门诊的连续ET患者。纳入的受试者临床诊断为药物难治性ET，并完成了包括常规SEMG震颤研究在内的术前检查。
87名受试者中，9名（10%）被DBS神经科医生临床怀疑为功能性震颤。电生理学证实7/9为功能性震颤特征，另外2/9为ET；并新发现5例功能性震颤病例。共有12例确诊的功能性震颤病例：1例为孤立性，11例为功能性震颤与ET混合。11例混合性患者中，6例功能性叠加较轻的患者被批准手术。其余5例功能性叠加中度至重度的患者和1例孤立性功能性震颤患者被转诊至功能性震颤运动再训练项目。其中，1例混合性震颤患者在项目完成后仍有残留的致残性器质性ET，后来被批准手术。因此，5/87例患者（6%）避免了不必要的手术。
在转诊接受手术的患者中，功能性震颤可能经常叠加在“药物难治性”ET上，在我们的四级转诊DBS中心，每7例患者中就有1例受影响。电生理学研究有助于常规筛查患者并预防不必要的手术。
