Movement disorders such as dystonia or spasms are neurological conditions, which means they are caused by problems in the nervous system. The most common examples of this kind of disorder are:
Hemifacial spasms
Hemifacial spasms (HFS) are irregular and involuntary muscle spasms on one side of the face. The contractions may be tonic (one intense contraction) or clonic (repeated rhythmic contractions). HFS commonly begins from the age of 40 onwards and is more common in women than in men.
Causes
The most common cause of HFS is a compression of the blood vessels around the root of the facial nerve, which irritates the nerve and causes muscles in the face to contract involuntarily. Other causes include cholesteatoma (a growth in the middle ear), acoustic neuroma (a growth on the nerve connecting the ear to the brain), facial nerve neuroma (a growth on the facial nerve), and adenoid cystic tumors (a growth at the back of the nasal cavity). When diagnosing HFS, it is first necessary to exclude other facial movement disorders, such as blepharospasm (eyelid twitches), facial myokimia (shivering), oromandibular dystonia (contractions of the mouth, jaw and tongue muscles), facial tics, and post Bell’s palsy synkinesis (quivering).
Treatment
- Medication
- Botulinum toxin (BoNT): Resulting in improvements in between 75% and 100% of patients, BoNT injections have been reported to improve patients’ quality of life. The benefits of Botulinum toxin serotype A (BoNT/A) appear within 1-3 days after treatment, although they can take up to 2-3 weeks in some patients. In most cases, however, the effects peak within 2 weeks of treatment and are maintained for a further 6-8 weeks. Repeated injections are usually required for 3-6 months.
- Surgical treatment: The most likely form of surgery is microvascular decompression, which requires an incision to be made behind the ear on the affected side.
Blepharospasm (eyelid twitches)
Blepharospasm is a localized form of involuntary muscle contractions. This particular condition affects the eye muscles, named “orbicularis oculi”, and results in repetitive blinking or sustained eyelid closure. In severe cases, the muscles can contract and force one eyelid to remain closed, resulting in functional blindness. Blepharospasm usually begins from the age of 40 onwards and is more common in women than in men.
Causes
- Benign essential blepharospasm: The exact causes of this form of eyelid twitching remain unknown, although stress, fatigue and certain irritants are believed to aggravate this condition.
- Secondary blepharospasm: This more persistent form of eyelid twitching is caused by conditions such as damage to the brain resulting from inflammation or damaged blood vessels, or it can also be caused by inherited conditions, particularly metabolic or neurodegenerative disorders.
Treatment
- Medication
- Botulinum toxin (BoNT): Botulinum toxin serotype A (BoNT/A) injections lead to improvements in between 72% and 93% of patients. The benefits typically appear between 3 and 4 days after treatment, and can last for between 12 and 16 weeks.
Spasmodic torticollis (extreme neck muscle contractions)
Spasmodic torticollis, also known as cervical dystonia (CD), is one of the most common types of muscle contraction disorders, with women more likely than men to be affected. The condition is characterized by abnormal involuntary contractions of neck and/or shoulder muscles, resulting in the head twisting to one side, repetitive neck movements and abnormal posture.
Causes
- Genetic
- Side-effects of some medications
- Environmental factors
Treatment
The goals of treatment are to correct the abnormal posture, ease any pain in the neck, and prevent secondary complications such as permanent damage to the muscle, pinched nerve or pinched spinal cord.
- Oral medication
- Physical therapy
- Botulinum toxin (BoNT): BoNT injections have a high rate of success with very few recorded side effects.
- Surgical treatment