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Year : 2018  |  Volume : 66  |  Issue : 6  |  Page : 1847--1849

Congenital bilateral perisylvian syndrome

Chinky Chatur1, Ankit Balani2,  
1 Department of Radiology, Yashoda Hospital, Somajiguda, Hyderabad, Telangana, India
2 Department of Radiology, Vijaya Diagnostic Centre, Hyderabad, Telangana, India

Correspondence Address:
Dr. Ankit Balani
61, Shyam Nagar, Pal Link Road, Jodhpur, Rajasthan

How to cite this article:
Chatur C, Balani A. Congenital bilateral perisylvian syndrome.Neurol India 2018;66:1847-1849

How to cite this URL:
Chatur C, Balani A. Congenital bilateral perisylvian syndrome. Neurol India [serial online] 2018 [cited 2022 Jun 25 ];66:1847-1849
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Full Text

A 12-year old female patient presented to the neurology outpatient department of our hospital with complaints of delayed milestones with cognitive impairment. There was a history of dysarthria and drooling of saliva. Since last 3 years, the patient had a history of episodes of momentary lapses of awareness with loss of muscle tone (atypical absence seizures) associated with a history of sustained muscle contraction followed by loss of muscle tone. The birth history was unremarkable. Family history revealed no known consanguinity. General examination revealed no dysmorphic features. Neurological examination revealed cognitive deficit with an intelligent quotient of 68. There was severe dysarthria with restriction of tongue movements. There was mild atrophy of lower limb muscles below the knee with bilateral exaggerated and extensor plantar reflexes. Electroencephalography (EEG) revealed infrequent intermittent, irregular bursts of sharp waves lasting for 0.5–2 s which were generalised, bilaterally synchronous, present throughout the tracings in awake phases and triggered by hyperventilation, suggesting the presence of generalised epilepsy. Magnetic resonance imaging (MRI) of the brain revealed bilateral, nearly symmetrical thickening of grey matter intermixed with shallow sulci and broad gyri involving the perisylvian regions extending dorsally upto the perirolandic region with exposure of insula [Figure 1], [Figure 2], [Figure 3]. The body of the lateral ventricles showed an inverted appearance. The cortical thickness in the perisylvian region measured upto 10 mm. The clinical features of oropharyngoglossal dysfunction with severe dysarthria and imaging features of perisylvian polymicrogyria suggested the diagnosis of congenital bilateral perisylvian syndrome. The parents were counselled about the disease and the patient was given training in swallowing and oral motor skills with speech therapy.{Figure 1}{Figure 2}{Figure 3}

Congenital bilateral perisylvian syndrome, also known as bilateral periopercular syndrome or perisylvian polymicrogyria, is a developmental neurological disorder characterised by homogeneous clinico-radiological findings with the underlying abnormality being polymicrogyria.[1],[2],[3] Clinically, the patients present primarily with pseudobulbar paresis. Dysarthria and severe restriction of tongue movements are common, as was seen in our index case. Many of the patients have seizures, as well as delayed motor and language milestones.[1],[3] Imaging characteristically reveals perisylvian and perirolandic cortical malformations (polymicrogyria). Polymicrogyria is a post-migrational developmental malformation in which neurons reach the final destination in the cortex; however, they have an abnormal distribution. There are multiple abnormally small convolutions with too few sulci. The opercula are dysplastic and incomplete and the Sylvian fissures are wide and underdeveloped. MRI also helps in grading the severity (Grade 1 being the most severe and Grade 4 the mildest): Grade 1, perisylvian microgyria extending to the frontal or occipital pole; Grade 2, polymicrogyria extending beyond the perisylvian region but not to either pole (as in our index case); Grade 3, polymicrogyria of the perisylvian region only, and Grade 4, polymicrogyria restricted to posterior perisylvian regions only.[3] The exact timing and mechanism of development of this disorder is unclear with postulation of the insult occurring before the 30 weeks of gestation, the time when opercula usually overrides the insula.[1] Familial, autosomal and X-linked inheritance has been reported. There is no cure for the perisylvian syndrome. Multidisciplinary rehabilitative measures including speech therapy, training in oral motor skills and swallowing as well as tongue muscle exercises can help the patients. If feeding is severely impaired, percutaneous gastrostomy would be of help.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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1Kuzniecky R, Andermann F. The congenital bilateral perisylvian syndrome: Imaging findings in a multicenter study. CBPS Study Group. AJNR Am J Neuroradiol 1994;15:139-44.
2Taneja S, Chaturvedi A. Bilateral perisylvian syndrome- A case report. Indian J Radiol Imaging 2006;16:169-71.
3Barkovich AJ. Current concepts of polymicrogyria. Neuroradiology 2010;52:479-87.