A convulsive tic, or hemifacial spasm, is described as a facial muscle spasm supplied by the VIIth cranial nerve.

This condition is often associated with compression of the nerve by an adjacent blood vessel.

Spasms may be clonic or tonic movements involving muscles of part or most of one-half of the face. These movements are also referred to as contractions.

Tests to diagnosis and evaluate this condition may include some or all of the following measures: a complete history; physical and neurological examinations; blood studies; electromyography (EMG); computed tomography (CT) scan; and magnetic resonance imaging (MRI).

Specific treatment includes anticonvulsants or botox injections. In some cases, decompressive surgery is required.

Recovery may be prolonged. Physical therapy may be needed for the duration of recovery and long-term medication may be needed.

• None.

• Depending on frequency, severity, muscle groups involved. 38 CFR 4.124(a) [Schedule of ratings-neurological conditions and convulsive disorders]