T1 Nerve Root Neurectomy for Finger Flexor Spasticity: Insights from a Successful Intervention

Background: The management of finger flexor spasticity (FFS) remains challenging. Traditional surgical approaches like peripheral neurotomies (PNs) and C8 cervical nerve root transection often achieve initial success in relieving FFS but are prone to rebound and recurrence. To address this limitation, we propose T1 nerve root neurectomy as a novel intervention. Methods: Among 19 patients with finger and thumb flexion spastic paralysis treated with T1 neurectomy, two also underwent contralateral C7 (CC7) or phrenic nerve (PhN) transfer for T1 repair. Patients were divided by preoperative finger extension strength into Group A (complete paralysis, n=10) and Group B (preserved function, n=9). Changes in extrinsic finger flexor muscle tone (EFFMT) and flexor pollicis longus muscle tone (FPLMT), as well as hand function, were assessed using the Modified Ashworth Scale (MAS) and the House Functional Classification (HFC), respectively. Results: The median follow-up duration was 24.0 months (IQR 20.0-44.0). Both EFFMT and FPLMT showed a significant decrease in MAS grades, from 4 (IQR 3-4) to 2 (IQR 1-3) (P < 0.001) and from 4 (IQR 4-4) to 1 (IQR 1-3) (P < 0.001), respectively. The HFC grade for hand function improved by a median of 1 grade in Group A (IQR 0.8–2.0; P = 0.01) and 3 grades in Group B (IQR 2.5–3.5; P = 0.01). Group B demonstrated significantly greater improvement compared to Group A (β = 1.83, P = 0.012). Conclusions: T1 neurectomy demonstrated durable efficacy in relieving FFS and significantly improved hand function, particularly in patients with preserved finger extension function.