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Ultrasound treatment for treating the carpal tunnel syndrome: randomised “sham” controlled trial

BMJ 1998; 316 doi: (Published 07 March 1998) Cite this as: BMJ 1998;316:731
  1. Gerold R Ebenbichler, assistant doctora,
  2. Karl L Resch, senior lecturerb,
  3. Peter Nicolakis, assistant doctora,
  4. Günther F Wiesinger, assistant doctora,
  5. Frank Uhlc, professor,
  6. Abdel-Halim Ghanem, assistant doctora,
  7. Veronika Fialka, head of departmenta
  1. a Department of Physical Medicine and Rehabilitation, University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria,
  2. b Department of Complementary Medicine, University of Exeter, Exeter
  3. c Department of Neurology, University of Vienna
  1. Correspondence to: Dr Ebenbichler
  • Accepted 11 November 1997


Objective: To assess the efficacy of ultrasound treatment for mild to moderate idiopathic carpal tunnel syndrome.

Design: Randomised, double blind, “sham” controlled trial with assessments at baseline, after 2 weeks' and 7 weeks' treatment, and at a follow up assessment 6 months later (8 months after baseline evaluation).

Setting: Outpatient clinic of a university department of physical medicine and rehabilitation in Vienna.

Subjects: 45 patients with mild to moderate bilateral carpal tunnel syndrome as verified by electroneurography.

Intervention: 20 sessions of ultrasound (active) treatment (1 MHz, 1.0 W/cm2, pulsed mode 1:4, 15 minutes per session) applied to the area over the carpal tunnel of one wrist, and indistinguishable sham ultrasound treatment applied to the other. The first 10 treatments were performed daily (5 sessions/week); 10 further treatments were twice weekly for 5 weeks.

Main outcome measures: Score of subjective symptom ratings assessed by visual analogue scale; electroneurographic measures (for example, motor distal latency and sensory antidromic nerve conduction velocity).

Results: Improvement was significantly more pronounced in actively treated than in sham treated wrists for both subjective symptoms (P<0.001, paired t test) and electroneurographic variables (motor distal latency P<0.001, paired t test; sensory antidromic nerve conduction velocity P<0.001, paired t test). Effects were sustained at 6 months' follow up.

Conclusion: Results suggest there are satisfying short to medium term effects due to ultrasound treatment in patients with mild to moderate idiopathic carpal tunnel syndrome. Findings need to be confirmed, and ultrasound treatment will have to be compared with standard conservative and invasive treatment options.

Key messages

  • Chronic entrapment of the median nerve at the wrist (the carpal tunnel syndrome) is probably the most common peripheral nerve lesion

  • No satisfactory conservative treatment is available at present

  • Twenty sessions of ultrasound treatment show good short and medium term efficacy in patients with bilateral, mild to moderate forms of the carpal tunnel syndrome

  • Optimal treatment schedules of ultrasound treatment alone or in combination with other non-surgical treatments await elucidation


    • Accepted 11 November 1997
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