The main objective of the study is to estimate the efficiency and to determine the optimal dose of Botulinum toxin A, administered by intramuscular way in cervical spasms after radiotherapy, as well as the optimal sites for these injections.

The concerned muscular groups are the sternocleidomastoid (SCM), the trapezius muscle and the splenius capitis.

Inclusion Criteria:

• Patients from 18 to 75 years old;
• malignant Tumor of aerodigestive ways, in forgiveness;
• Treatment containing the external radiotherapy ended since > 6 months
• Life expectancy > 6 months;
• patient complaining from cervical spasms with functional disability;
• Negative Pregnancy test;
• Women under effective contraception;
• Patients benefiting from a national insurance scheme;
• Patient having given a written consent.

Exclusion Criteria:

• Cervico-facial Surgery with reconstruction by pedicled flap
• Implantable Chamber with catheter in the internal jugular vein near the spasm;
• Muscular, neurological Pathology or malformative pulling a disorder of perception of the pain, an amyotrophy, a muscular weakness affecting the cervical axis or the upper limbs;
• Disorder generalized by the muscular activity (ex myasthenia);
• Cervical osseous or muscular Pathology pulling pains and disability before the beginning of the treatment (cervical degenerative osteoarthritis diagnosed to the cervical radiography, the slipped disc);
• Previous cervical injection of botulinum toxin ;
• Local Infection at the level of one of the sites proposed for injection;
• Histories of epilepsy;
• Patients presenting a hypersensitivity to the botulinum neurotoxin A or in one of its excipients;
• Patients under anticoagulation therapy, Under antibiotic treatment by aminoglycosides or amino 4 quinoline, under myorelaxant treatment or that must undergo an intervention with curarisation;
• Patients for whom a surgical operation is planned in the zone interested in the treatment
• Pregnant or breast-feeding Women;
• Patients for whom questionnaires will not be assessable (handicaps of communication, patient not speaking French, etc.).