gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

Clinical assessment of the stretch reflex of the spastic ankle: a biomechanical analysis

Meeting Abstract

  • corresponding author P. Decq - Service de Neurochirurgie, Hôpital Henri Mondor, Créteil
  • J. Carrillo-Ruiz - Service de Neurochirurgie, Hôpital Henri Mondor, Créteil
  • M. Shin - Service de Neurochirurgie, Hôpital Henri Mondor, Créteil
  • Romain Gherardi - Unité INSERM 0011, Hôpital Henri Mondor, Creteil

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. DocP038

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2005/05dgnc0306.shtml

Veröffentlicht: 4. Mai 2005

© 2005 Decq et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective

The detected stiffness in spastic ankle includes the intrinsic muscular stiffness and the strength developed by the stretch reflex itself, which is supposed to be exaggerated in spastic patients. The aim of this study is to measure the different components of the stiffness detected during a passive dorsal flexion of the ankle in spastic patients.

Methods

The triceps surae stretch reflex is studied in 16 patients with an equinus spastic foot and in 11 controls, at low, intermediate and rapid speeds, knee in extension then in flexion. A force sensor is placed between the clinician hand and the sole of the foot. It is synchronised with an ankle goniometer and a surface EMG of the soleus and the medial and lateral heads of the gastrocnemius. The angular speeds are measured in °/sec and the stiffness by the ratio ? force (Kg) / ? angular degree (°) of the ankle from the neutral position to the maximal dorsi-flexion. EMG activity is noted as present or absent. Each measurement is repeated three times then averaged. A lidocaïne percutaneous motor blockage is performed to transiently eliminate spasticity (any EMG activity). Measurements were performed before and after blockage.

Results

The clinically assessed speeds were : 6,45 to 8, 80 °/sec (« slow » speed (SL)), 19,66 à 22,86 °/sec (« intermediate » speed (IS)) and 100 à 162, 80 °/sec (“rapid” speed (RS)). Average triceps stiffness is greater in patients as compared with controls whatever the speed: 0,31 versus 0,65 F/° (p=6,75 E-05) (SP), 0,26 versus 0,90 F/° (p=2,96 E-05) (IS) and 0,29 versus 0,79 F/° (p= 5,73 E-07) (RS).

The number of patients with an EMG activity increase from low (half of the patients) to rapid (all patients) speed. The same result is observed with the flexion of the knee. All patients had a clonus at rapid speed, when the knee is flexed. The soleus motor block leads to the disappearance of the EMG activity on the three heads of the triceps in all patients when the knee is flexed. Clonus disappears in all patients.

The clinically assessed triceps stiffness is not statistically different before and after the soleus motor blockage although the disappearance of the EMG activity, whatever the speed or the position of the knee.

Conclusions

The manual passive stretch of the triceps is unable to determine the presence or absence of spasticity, as defined as an EMG induced activity. The clonus is the only clinical event that the clinician is able to detect.