TY  - JOUR
A1  - Tenberg, Sarah
A1  - Weinig, Jonas
A1  - Niederer, Daniel
A1  - Vogt, Lutz
A1  - Leisse, Markus
A1  - Müller, Steffen
T1  - Effects of kilohertz versus low-frequency electrical stimulation of the wrist extensors in patients after stroke: A randomized crossover trial
T2  - PM&R
N2  - Background: Electrical stimulation is an effective treatment method for improving motor function after stroke, but the optimal current type for patients with stroke and arm paresis remains unclear.

Objective: To compare the effects of kilohertz frequency with low-frequency current on stimulation efficiency, electrically induced force, discomfort, and muscle fatigue in patients with stroke.

Design: A randomized crossover study.

Setting: Neurological inpatient rehabilitation clinic in Germany.

Participants: A total of 23 patients with arm paresis after stroke within the last 6 months were recruited, 21 were enrolled, and 20 completed the study (7 females; mean ± SD: 66 ± 12 years; 176 ± 11 cm; 90 ± 19 kg; 57 ± 34 days since stroke).

Intervention: All patients underwent both kilohertz and low-frequency stimulation in a randomized order on 2 days (48-hour washout). Each day included a step protocol with a gradual increase in stimulation intensity, starting at the first measurable force (up to 12 steps, 1 mA increments, 8 seconds stimulation, 60 second rest) and a fatigue protocol (30 repetitions, 8 second stimulation, 3 second rest).

Main Outcome Measure: Primary outcome was stimulation efficiency (electrically induced force/stimulation intensity) [N/mA], measured during each step of the stepwise increase in current intensity protocol.

Results: Linear-mixed-effects models showed significantly higher stimulation efficiency for low-frequency stimulation (mean difference 0.14 [95% confidence interval, 0.01–0.27 N/mA], p = .031). However, current type did not significantly affect electrically induced force, level of discomfort, or muscle fatigue (p > .05).

Conclusion: The findings suggest that low-frequency stimulation is more efficient than kilohertz-frequency stimulation. However, both current types yield similar effects on force, discomfort, and fatigue, making them both viable options for wrist extensor stimulation in patients after stroke. Considering the variability among individuals, customizing the current type based on electrically induced force and perceived discomfort may enhance therapeutic outcomes. Further research on the long-term treatment effects of both current types is warranted.
KW  - stroke
KW  - motor function
KW  - electrical stimulation
KW  - kilohertz stimulation
KW  - low-frequency stimulation
KW  - Schlaganfall
KW  - Parese
KW  - Arm
KW  - Elektrotherapie
KW  - Frequenz
KW  - Niederfrequenz
KW  - Effizienz
Y1  - 2026
UR  - https://hst.opus.hbz-nrw.de/frontdoor/index/index/docId/1105
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:tr5-11055
VL  - 17
IS  - 9
SP  - 1055
EP  - 1068
PB  - Wiley
ER  -