Foix–Chavany–Marie syndrome

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.[4]

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.[1]

Strokes are one of the most common causes of Foix–Chavany–Marie syndrome. The type of strokes associated with this syndrome include embolic and thrombotic strokes. Strokes affecting the middle cerebral artery and the branches that pass through or near the operculum are characteristic of FCMS.[1]

Symptoms of infections specifically HIV and herpes simplex encephalitis can cause FCMS. Numerous lesions can develop with HIV infections, which likely result in the development of FCMS.[1][5]

Epilepsy symptoms such as seizures can spread discharges that cause FCMS. This causation results in the only reversible development of FCMS as it is the only cause that allows full recuperation from speech, swallowing, and mastication difficulties when treated.[3] This causation is most commonly seen in children with FCMS.[3]

• Tumors
• Multiple Sclerosis
• Neurodegenerative diseases
• Acute disseminated encephalomyelitis
• Moyamoya disease
• Vasculitis[6]
• Trauma

The anatomic basisFoix–Chavany– for the automatic voluntary dissociation is characterized by the following. Neurons that lie adjacently in the operculum project supranuclear fibers to the cranial nuclei for the voluntary movement of facial, pharyngeal, lingual, and masticatory muscles. Emotional movement of these muscles is controlled by alternative pathways that run from the amygdala and lateral hypothalamus to the brainstem via the medial forebrain bundle and dorsal longitudinal fasciculus.[8]

The opercular cortex surrounding the insula is separated by two anatomical components: the ascending rami of the lateral sulcus and the posterior rami into three different sections of the operculum.[3]

1. Frontal operculum formed by posterior part of the inferior frontal gyrus.
2. Fronto-parietal opercula formed by the lowermost part of the precentral and postcentral gyrus and the anterior and lowermost part of the inferior parietal lobule.
3. Temporal opercula formed by the superior temporal gyrus.[3]

FCMS shares similar characteristics with the following disorders: catatonia, akinetic mutism, orobuccal apraxia, Broca's aphasia, pseudobulbar palsy, bulbar palsy secondary to myasthenia gravis, Guillain–Barré syndrome, and brainstem strokes.[1]

In determining a diagnosis between with catatonia, akinetic mutism, and FCMS, a person must demonstrate their ability to perform voluntary function of the limbs. Patients with catatonia or akinetic mutism are not able to perform voluntary commands that involve the use of limbs, while patients with FCMS still possess voluntary usage of limbs.[1] If a person can demonstrate ability in voluntary usage of limbs, catatonia and akinetic mutism are most likely ruled out from the diagnosis.

In determining a diagnosis between Broca's aphasia and FCMS, a person must demonstrate their ability in voluntary movement of cranial musculature. People with Broca's aphasia may not exhibit a complete loss of voluntary movement facial muscles, pharyngeal muscles, laryngeal muscles, brachial muscles, tongue muscles, and muscles of the mouth that aid in chewing. These voluntary functions may still be present, to varying degrees. People with FCMS do not possess this ability. For people with FCMS, voluntary movement of cranial musculature is completely absent.[1]

In determining a diagnosis between pseudobulbar palsy, a person must demonstrate whether or not muteness is present, as well as the ability to move the facial, buccal, lingual, and pharyngeal muscles. People with pseudobulbar palsy exhibit, to varying degrees, an ability in these functions, while patients with FCMS do not.[1]

There are three general classes of tests utilized by physicians when determining a diagnosis for FCMS: (1) automatic-voluntary dissociation assessment, (2) psycholinguistic testing, and (3) neuropsychological testing.[9] In addition, brain scanning techniques are utilized to observe whether ischemic abnormalities or lesions are present within the operculum region of the cortices.

FCMS is largely characterized by the paralysis of voluntary movement in facial, lingual, pharyngeal, and masticatory muscles, while automatic, involuntary functions of these four muscle groups remain.[3] Automatic functions are performed by inducing involuntary reflexes, such as palatal, laryngeal, blink, and gag reflexes. Other involuntary functions that are tested include spontaneous smiling, laughter, and yawning.[10] Patients with the disorder are able to these functions under automatic, involuntary reflex. An individual's ability to perform these functions voluntarily are tested determined through a series of commands by the physician. Typically, individuals with the disorder are not able to perform any of these functions upon command. Dissociation between automatic and voluntary dissociation is indicated by an individual's ability to perform the involuntary, automatic functions, and their inability to perform the same actions, voluntary.

Psycholinguistics pertain to the psychological and neurobiological components that allow humans to acquire, utilize, comprehend, and produce language. The tests most commonly used for psycholinguistic testing include the Dutch version of Aachen aphasia test, syntactic comprehension test, and the Token test.[10] Psycholinguistics allow physicians to narrow down and rule out other disorders that may be similar to FCMS when diagnosing a patient.

Neuropsychology is the study of neurobiology and psychology. Neuropsychological tests are utilized for the purpose of observing an individual's abilities in cognitive functioning, reasoning, and memories.[10] The tests most commonly used for neuropsychological testing include WAIS-III, Stroop test, Bourdon Wiersma test, and the Rey–Osterrieth complex figure test. These tests allow physicians to evaluate the degree to which the bilateral lesions in the operculum have been affected, and allow for the determination of proper treatment.

Scanning techniques include EEG, SPECT, MRI, and CT brain scanning.[1][2] These additional techniques are useful in determining what type of lesion the patient has, and allows physicians to determine more effective ways in treating the patient.

(A) CT scan of a patient with middle cerebral artery stroke illustrating hypodensity areas within the temporal and frontal lobes. (B) CT scan displaying an ischemic stroke bordering the fronto-parietal opercular cortex (red arrow) and a left-sided ichemic lesion of the fronto-parietal opercular cortex (blue arrow).

MRI is one of the best techniques that can detect the lesions in the brain of the FCMS that some of the times are missed by just using a Computer-Tomography Scan. Also, this type of imaging can reveal right frontal lobes contusions encompassing the anterior operculum, the premotor area, and the association area.[10]

This computer-tomography type of imaging is one of the most used in any clinical environment and although it can detect some of the brain areas affected by a stroke or a trauma it does not provide the same acuity as the magnetic resonance imaging. CT scans can also reveal, in patients with the syndrome, the bilateral cortical infarcts located in the posterior frontal region involving the opercular areas.[3]

The single photon emission computed tomography of the brain can show uptake area in the right frontal lobe and normal uptake are in the left hemisphere.[10] This type of imaging can give a more detailed view of a specific region of the brain.

An electroencephalography (EEG) is also used in patients with the FCMS and it can reveal focal slowing and epileptic discharges from left fronto-temporal regions.[3]