Foix–Chavany–Marie Syndrome (FCMS),–Chavany– also known as bilateral opercular syndrome, is a neuropathological disorder characterized by paralysis of the facial, tongue, pharynx, and masticatory muscles of the mouth that aid in chewing. The disorder is primarily caused by thrombotic and embolic strokes, which cause a deficiency of oxygen in the brain. As a result, bilateral lesions may form in the junctions between the frontal lobe and temporal lobe, the parietal lobe and cortical lobe, or the subcortical region of the brain. FCMS may also arise from defects existing at birth that may be inherited or nonhereditary. Symptoms of FCMS can be present in a person of any age and it is diagnosed using automatic-voluntary dissociation assessment, psycholinguistic testing, neuropsychological testing, and brain scanning. Treatment for FCMS depends on the onset, as well as on the severity of symptoms, and it involves a multidisciplinary approach.
Classification
There are two forms (also referred to as "classifications") of FCMS; bilateral and unilateral. The bilateral form is most common (also referred to as the "classical form") and is caused by the formation of lesions on both sides of the anterior or posterior region of the operculum. In contrast, the unilateral form is rare and is caused by the formation of lesions on one side of the anterior or posterior region of the operculum. Lesions located in the anterior regions of the operculum are associated with motor deficits and anarthria, a total absence of the ability to form speech or language. Lesions located in the posterior regions of the operculum are associated with parietal opercular functions. The two classifications of FCMS were established based on the location of the lesion, stroke, and trauma affecting the brain. Classifying FCMS based solely upon lesions yields five specific subtypes of FCMS currently known to fall into the bilateral and unilateral categories: Bilateral anterior opercular syndrome (lesion in both the anterior or in the frontal operculum) Opercular-subopercular syndrome (lesions in the opercular cortex on one side and the subopercular lesion in the contralateral side). Subopercular syndrome (lesions in the subcortical corticobulbar projections only). Unilateral anterior syndrome involving the frontal operculum. Posterior syndrome involving the junction between the frontal and the parietal lobe of the operculum.
Bilateral
The bilateral form of FCMS (also known as facio-labio-pharyngo-glosso-laryngo-brachial paralysis) is consistent with the classic presentation of bilateral corticobulbar involvement. It is characterized by well-preserved automatic and reflex movements. It is caused by lesions in the cortical or subcortical region of the anterior opercular area surrounding the insula formingFoix–Chavany– the gyri of the frontal, temporal, and parietal lobes.
Unilateral
The unilateral operculum syndrome is a very rare form of FCMS caused by the formation of unilateral lesions. In this form of FCMS, the unaffected hemisphere of the brain compensates for the unilateral lesion. Usually, this occurs when the unaffected region is the individual's dominant hemisphere.
Symptoms
An individual affected with FCMS develops disabilities associated with voluntary movements using the facial, lingual, pharyngeal, and masticatory muscles. However, the reflexive and autonomic functions of these muscles groups are usually intact. Common symptoms include drooling, an inability to elevate and depress the mandible, difficulty chewing, inability of protruding tongue, swallowing, and loss of speech.
Classification of the disorder is distinguished by the location of the lesions formed, which causes certain symptoms to be present or amplified. FCMS caused by the formation of bilateral lesions causes paralysis of the facial, lingual, pharyngeal, and masticatory muscles. This form of FCMS involves voluntary-autonomic dissociation and an inability to form speech. The formation of bilateral lesions confined to the posterior operculum has a distinct symptom of word deafness, an inability to understand language.
FCMS caused by the formation of lesions unilaterally causes muteness of speech and upper motor neuron cranial nerve paresis, muscular weakness. The formation of unilateral lesions confined to the posterior operculum has distinct symptoms that includes sensory loss in the hand and face contralateral to the location of the lesion.