LETTERS TO THE EDITOR
DORSAL INTEROSSEOUS NEUROPRAXIC COMPRESSION SYNDROME Dorsal interosseous rieuropraxic compression syndrome was recently reported following the use of Canadian crutches.’ Because the nervc conduction studies included a “slowing of the radial sensory response” as well as electromyographic changes characteristic of denervation in the extensor carpi radialis ,muscle, it appears that the compressive lesion is more proxirnal and involves the radial nerve before the bifurcation into the dorsal interosseous nerve and superficial sensory nerve. The extensor Capri radialis muscles (longus and brevis) are supplied before the dorsal interosseous nerve enters the supinator just below the neck of the radius. Pressure from the edge of a metal crutch at the proximal area of the forearm is too far distal to fully explain the reported findings. Compression ot‘ the radial nerve by the triceps muscle itself has been As the terminal branch of the posterior cord, the radial nerve descends behind the axillary artery and lies on the subscapularis muscle arid tendons of the latissimus dorsi and teres major. It then courses between the long and medial heads of the triceps muscle to the humeral spiral groove. We recently reported a radial nerve compressive syndrome from repeated contraction of the triceps muscle during walker usage.5 We suggest that this might also be the situation with the case reported. T h e described woman with “overdeveloped upper extremity musculature” (presumably including the right triceps muscle) is seemingly at risk for a triceps radial nerve compressive lesion during a “strenuous day on crutches” with repeated arm extension. This triceps mechanism would appear to more completely explain the EMGINCS findings (which include abnormalities in the radial SNAP and EMG of the ECK) than the proposed dorsal interosseous compression by the cuff of the Canadian crutch.
1. Siegel IM: Dorsal interosseous nerve compression syndrome from the use of a Canadian crutch. Muscle h’em 1988;ll: 1273- 1274. 2. Lotem M, Fried A, et al.: Kadial palsy following muscular effort J Bone Joint Surg [Br] 197 1 ;53:500-506. 3. Manske PR: Compression of the radial nerve by the triceps muscle. J Bone Joint Surg [Am] 1977;59:835-836. 4. Sunderland S: Nerve and Nerue lnjwm, ed 2, Edinburgh,
Churrhill Livingstone, 1978. 5 . Ball NA, Sternpicn LM, Pasupuleti K, Wertsch JJ: Radial nerve palsy: a complication of walker usage. Arch P h y M e d Rdiabil, in press.
DORSAL INTEROSSEOUS NERVE NEUROPRAXIC COMPRESSION SYNDROME: A REPLY T h e comments of Drs. Ball and Wertsch‘ regarding our findings2 are appreciated. It should be stressed that the EMG findings in the extensor carpi radialis wcre much milder than those of the extensor digitorurn cornmunis and extensor carpi ulnaris muscles. Additionally, the patient was most weak in terms of finger- extension, and the action of the extcnsor carpi radialis was preserved. Putting the electrophysiological and clinical findings together, a diagnosis of posterior interosseoiis nerve compression seemed most likely, even though the electrophysiological signs for this were not quite purc.
Irwin M. Siegel, MD Russell H. Glantz, MD Department of Neurological Sciences Rush-Presbyterian-St, Luke’s Medical Center Chicago, Illinois 60612-3864 1. Ball NJ, Wertsch JJ: Dorsal interosseous nerve neuroNerve praxic compression syndrome. Muscle 1989;12:xxx-xxx. 2. Siegel I M : Dorsal interosseous nerve compression syndrome from the use of a Canadian crutch. M u d e Nerue 1988;11:1273-1274.
Nancy A. Ball, MD Jacqueline J. Wertsch, MD Department of Rehabilitation Medicine Northwestern University Medical School Chicago, Illinois 6061 1
172
MUSCLE & NERVE
February 1990
DORSAL INTEROSSEOUS NEUROPRAXIC COMPRESSION SYNDROME Dorsal interosseous rieuropraxic compression syndrome was recently reported following the use of Canadian crutches.’ Because the nervc conduction studies included a “slowing of the radial sensory response” as well as electromyographic changes characteristic of denervation in the extensor carpi radialis ,muscle, it appears that the compressive lesion is more proxirnal and involves the radial nerve before the bifurcation into the dorsal interosseous nerve and superficial sensory nerve. The extensor Capri radialis muscles (longus and brevis) are supplied before the dorsal interosseous nerve enters the supinator just below the neck of the radius. Pressure from the edge of a metal crutch at the proximal area of the forearm is too far distal to fully explain the reported findings. Compression ot‘ the radial nerve by the triceps muscle itself has been As the terminal branch of the posterior cord, the radial nerve descends behind the axillary artery and lies on the subscapularis muscle arid tendons of the latissimus dorsi and teres major. It then courses between the long and medial heads of the triceps muscle to the humeral spiral groove. We recently reported a radial nerve compressive syndrome from repeated contraction of the triceps muscle during walker usage.5 We suggest that this might also be the situation with the case reported. T h e described woman with “overdeveloped upper extremity musculature” (presumably including the right triceps muscle) is seemingly at risk for a triceps radial nerve compressive lesion during a “strenuous day on crutches” with repeated arm extension. This triceps mechanism would appear to more completely explain the EMGINCS findings (which include abnormalities in the radial SNAP and EMG of the ECK) than the proposed dorsal interosseous compression by the cuff of the Canadian crutch.
1. Siegel IM: Dorsal interosseous nerve compression syndrome from the use of a Canadian crutch. Muscle h’em 1988;ll: 1273- 1274. 2. Lotem M, Fried A, et al.: Kadial palsy following muscular effort J Bone Joint Surg [Br] 197 1 ;53:500-506. 3. Manske PR: Compression of the radial nerve by the triceps muscle. J Bone Joint Surg [Am] 1977;59:835-836. 4. Sunderland S: Nerve and Nerue lnjwm, ed 2, Edinburgh,
Churrhill Livingstone, 1978. 5 . Ball NA, Sternpicn LM, Pasupuleti K, Wertsch JJ: Radial nerve palsy: a complication of walker usage. Arch P h y M e d Rdiabil, in press.
DORSAL INTEROSSEOUS NERVE NEUROPRAXIC COMPRESSION SYNDROME: A REPLY T h e comments of Drs. Ball and Wertsch‘ regarding our findings2 are appreciated. It should be stressed that the EMG findings in the extensor carpi radialis wcre much milder than those of the extensor digitorurn cornmunis and extensor carpi ulnaris muscles. Additionally, the patient was most weak in terms of finger- extension, and the action of the extcnsor carpi radialis was preserved. Putting the electrophysiological and clinical findings together, a diagnosis of posterior interosseoiis nerve compression seemed most likely, even though the electrophysiological signs for this were not quite purc.
Irwin M. Siegel, MD Russell H. Glantz, MD Department of Neurological Sciences Rush-Presbyterian-St, Luke’s Medical Center Chicago, Illinois 60612-3864 1. Ball NJ, Wertsch JJ: Dorsal interosseous nerve neuroNerve praxic compression syndrome. Muscle 1989;12:xxx-xxx. 2. Siegel I M : Dorsal interosseous nerve compression syndrome from the use of a Canadian crutch. M u d e Nerue 1988;11:1273-1274.
Nancy A. Ball, MD Jacqueline J. Wertsch, MD Department of Rehabilitation Medicine Northwestern University Medical School Chicago, Illinois 6061 1
172
MUSCLE & NERVE
February 1990
