Imaging diagnosis : Congenital Bilateral Perisylvian Syndrome.
Bilateral symmetrical polymicrogyria
The term “perisylvian” refers to the area (“peri” = about or around) of the sylvian fissure (lateral sulcus), which acts as the brain’s language and speech center. It is basically an organization anomaly in which the neurons reach their final destination in the cortex but are distributed abnormally.
The syndrome is one of a group of congenital neurological diseases characterized by slack muscles of the face and tongue, chewing and swallowing difficulties, delayed or abnormal speech and language development, epilepsy, and in certain cases, impairment of cognitive function and impaired mobility. Similar disorders were described first by the French neurologists Charles Foix, Jan Alfred Chavany and Julien Marie in 1926, and later by the English physician Cecil Charles Worster-Drought in 1956.
Genetic factors are very important, and there are families in which more than one person has the syndrome, although the symptoms may vary from person to person. Linked with a mutation on the long arm of the X chromosome (Xq27.2-q27.3 and Xq28). Disorders caused by mutations in genes on the X chromosome primarily affect boys.
Acquired, the Perisylvian syndrome may also be acquired, for example from a local malfunction in the blood circulation of the brain, or an infection in the relevant area of the temporal lobe during the foetal stage like congenital cytomegalovirus infection. In these cases the condition is not hereditary.
The most common symptoms are impairments of the mobility of the tongue and throat (pseudobulbar palsy), epilepsy and mild cognitive impairment.
In serious forms of the disease, neonates may have problems sucking and swallowing.
May not become apparent till the child starts eating solids. It can be difficult to chew, move food around in the mouth, and swallow. Drooling is common.
Child is slow to start talking or has speech difficulties. The most common symptoms are paralysis or impaired motor capacity of the organs necessary for speech (dysarthria) and difficulties coordinating movements (dyspraxia) of the mouth.
Unclear and slurred speech, as well as problems forming certain sounds, are signs of dysarthia whith as associated drooling and swallowing difficulties. Problems in moving the tongue and the mouth mean that children with the syndrome cannot purse their lips or whistle. Oral motor problems, which commonly cause difficulties eating, drinking and speaking, remain throughout life.
Oral motor problems may affect the growth of the lower jaw, which may be smaller than normal (micrognathia). Misalignment of the teeth (malocclusion) may mean that it is difficult to close the mouth completely and that the lower jaw protrudes.
Dyspraxia may be oral or verbal. Oral dyspraxia means that it is difficult to exert voluntary control over movements of the tongue and lips. Verbal dyspraxia means that it is difficult to form words, despite the relevant organs having normal functionality. The symptoms are the result of abnormalities in areas of the brain controlling the motor skills necessary for speech. In verbal dyspraxia it is difficult to make a connection between sounds and syllables, which is necessary to form words. The degree of severity varies. Less severe disabilities give rise to problems with multi-syllable and longer sentences, which become more difficult to formulate the longer they get. Severe dyspraxia may mean that the child cannot form syllables or words.
Other language and communication problems may also occur, including difficulties with grammar and phonology (speech sounds). Children with the syndrome may have specific reading and writing problems (dyslexia). Speech comprehension, however, does not appear to be affected.
Most individuals with this syndrome have epilepsy. Seizures may present as infantile spasms during the child’s first two years of life and develop into other, difficult to treat, forms of epilepsy as the child gets older. In infantile spasms the child experiences a series of short, sudden, cramp-like jerks of the arms, or wider, uncontrolled movements of the arms.
Physical disability characterized by stiffness in the arms, legs and neck. Stiff, malformed joints make it difficult to walk, and to move in general. Require special aids or a wheelchair.
Mild cognitive impairment and hyperactivity may also present. Individuals with intellectual disability require more time to understand and learn new skills.
The diagnosis is based on observation of the symptoms, as well as finding structural abnormalities on CT and MRI.
Treatment and Rehabilitation:
There is no cure for Perisylvian syndrome.
Training in oral motor skills and swallowing at an early stage.
Exercises to the muscles of the tongue.
Training in closing the mouth will help prevent deformities of the lower jaw.
Child may need to be fed with the help of a PEG (percutaneous endoscopic gastrostomy), a procedure where a feeding tube is inserted into the stomach directly through the abdominal wall.
Their epilepsy is often difficult to control as the nature of the attacks varies greatly. Medication is prescribed on the basis of type of seizure, EEG results and the effects of the medication.
Surgery may sometimes be used to control epileptic attacks. A vagus nerve stimulator can be an alternative if other measures fail. The vagus nerve is one of the twelve cranial nerves originating in the brain. In an operation the stimulator is placed under the left collar bone and it sends electric impulses to the brain with the help of an electrode placed around the vagus nerve in the neck. These impulses can reduce epileptic activity and attacks.
Speech therapist to assesses and treats chewing and swallowing problems, drooling and communication difficulties.
Treatment usually requires mutli-disciplinary teamwork. The major hospitals in Sweden have specialist teams (dysphagia and nutrition teams) for assessing and treating speech, eating and swallowing difficulties.
Dental treatment for chewing and oral hygiene in the form of dental braces.