Question: What is (are) Bilateral perisylvian polymicrogyria ?
Answer: Bilateral perisylvian polymicrogyria (BPP) is a rare neurological disorder that affects the cerebral cortex (the outer surface of the brain). Signs and symptoms include partial paralysis of muscles on both sides of the face, tongue, jaws, and throat; difficulties in speaking, chewing, and swallowing; and/or seizures. In most cases, mild to severe intellectual disability is also present. While the exact cause of BPP is not fully understood, it is thought to be due to improper brain development during embryonic growth. Most cases of BPP occur sporadically in people with no family history of the disorder; however, more than one family member may rarely be affected by the condition. Treatment is based on the signs and symptoms present in each person.
Source: GARD

Question: What are the symptoms of Bilateral perisylvian polymicrogyria ?
Answer: What are the signs and symptoms of Bilateral perisylvian polymicrogyria? The signs and symptoms of bilateral perisylvian polymicrogyria (BPP) vary but may include: Partial paralysis of muscles on both sides of the face, tongue, jaws, and throat Dysarthria Difficulty chewing Dysphagia Mild to severe intellectual disability Seizures and/or epilepsy Sudden, involuntary spasms of facial muscles Developmental delay The Human Phenotype Ontology provides the following list of signs and symptoms for Bilateral perisylvian polymicrogyria. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Atypical absence seizures - Cognitive impairment - Delayed speech and language development - Dyslexia - Generalized tonic-clonic seizures - Polymicrogyria - Pseudobulbar paralysis - X-linked dominant inheritance - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Bilateral perisylvian polymicrogyria ?
Answer: What causes bilateral perisylvian polymicrogyria? The exact underlying cause of bilateral perisylvian polymicrogyria (BPP) is unknown. The signs and symptoms associated with the condition are thought to be due to improper development of the outer surface of the brain (cerebral cortex) during embryonic growth. The cerebral cortex, which is responsible for conscious movement and thought, normally consists of several deep folds (gyri) and grooves (sulci). However, in people affected by BPP, the cerebral cortex has an abnormally increased number of gyri that are unusually small. Scientists believe that these abnormalities occur when newly developed brain cells fail to migrate to their destined locations in the outer portion of the brain. Specific non-genetic causes of polymicrogyria have been recognized, including exposure to cytomegalovirus infection (CMV) during pregnancy. Polymicrogyria has also been associated with certain complications in twin pregnancies.
Source: GARD