Successive motor nerve blocks to identify the muscles causing a spasticity pattern: example of the arm flexion pattern.
Botulinum Toxin A has been the main treatment for spasticity since the beginning of the 1990s. Surprisingly, there is still no consensus regarding injection parameters or, importantly, how to determine which muscles to target to improve specific functions. The aim of this study was to develop a systematic approach to determine this, using the example of the arm flexion pattern. We first determined anatomical landmarks for selective motor block of the brachialis nerve, using 20 forearms from 10 fresh cadavers in Ecole Européenne de Chirurgie and a university-based dissection centre, Paris, France. We then carried out selective blocks of the motor nerves to the brachialis, brachioradialis and biceps brachii in patients with stroke with an arm flexion pattern, in a University Rehabilitation Hospital, Garches, France. We measured: the resting angle of the elbow angle in standing (manual goniometer), active and passive range of extension, and spasticity using the Held and Tardieu and the Modified Ashworth scales. Range of passive elbow extension was also measured with the shoulder in 90° of flexion. The resting angle of the elbow in standing decreased by 35.0° (from 87.6 ± 23.7 to 52.6 ± 24.2°) with inhibition of brachialis, by a further 3.9° (from 52.6 ± 24.2 to 48.7 ± 23.7°) with inhibition of brachioradialis and a further 14.5° (from 48.7 ± 23.7to 34.2 ± 20.7°) with inhibition of biceps brachii. These results were consistent with the clinical evaluation of passive elbow range of motion with the shoulder at 90°. Sequential blocking of the nerves to the three main elbow flexors revealed that the muscle that limited elbow extension the most, was brachialis. This muscle should be the main target to improve the arm flexion pattern. These results show that it is important not simply to inject the most superficial or powerful muscles to treat a spastic deformity. A comprehensive assessment is required. The strategy proposed in this paper should increase the effectiveness of botulinum toxin injections by ensuring that the relevant muscles are targeted.
Service de Médecine Physique et de Réadaptation, Hôpital Raymond Poincaré, Garches, France.|'End:icap' U1179 INSERM, UFR des Sciences de la Santé - Simone Veil, Université Versailles Saint Quentin en Yvelines, Montigny le Bretonneux, France.|Ecole Européenne de Chirurgie (EEC), Paris, France.
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Genet
Service de Médecine Physique et de Réadaptation, Hôpital Raymond Poincaré, Garches, France.|Ecole Européenne de Chirurgie (EEC), Paris, France.
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Schnitzler
Service de Médecine Physique et de Réadaptation, CHRU Besançon, Besançon Cedex, France.
F
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Droz-Bartholet
Service de Médecine Physique et de Réadaptation, Hôpital Raymond Poincaré, Garches, France.|'End:icap' U1179 INSERM, UFR des Sciences de la Santé - Simone Veil, Université Versailles Saint Quentin en Yvelines, Montigny le Bretonneux, France.
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Salga
Laboratoire d'anatomie UFR SMP, Université Bourgogne/Franche-Comté, Besançon Cedex, France.|Service d'Explorations et Pathologies Neuro-musculaires, CHRU Besançon, Besançon Cedex, France.
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Tatu
'End:icap' U1179 INSERM, UFR des Sciences de la Santé - Simone Veil, Université Versailles Saint Quentin en Yvelines, Montigny le Bretonneux, France.|Service de Chirurgie Orthopédique, Hôpital Européen Georges Pompidou, Paris, France.
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Debaud
'End:icap' U1179 INSERM, UFR des Sciences de la Santé - Simone Veil, Université Versailles Saint Quentin en Yvelines, Montigny le Bretonneux, France.|Ecole Européenne de Chirurgie (EEC), Paris, France.|Service de Chirurgie Orthopédique, Hôpital Raymond Poincaré, Garches, France.
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Denormandie
Ecole Européenne de Chirurgie (EEC), Paris, France.|Service de Médecine Physique et de Réadaptation, CHRU Besançon, Besançon Cedex, France.|Laboratoire d'anatomie UFR SMP, Université Bourgogne/Franche-Comté, Besançon Cedex, France.
B
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Parratte
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001132:Arm / Q000294:innervation* / Q000502:physiology*; D002102:Cadaver; D005260:Female; D006429:Hemiplegia / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009128:Muscle Spasticity / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D009407:Nerve Block / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology
brachialis muscle; elbow flexion; hemiplegia; motor nerve block; spasticity