Syndrome characterized by cerebral hemiatrophy with marked asymmetry of the cerebral hemispheres and characteristic changes on skull radiograph. These changes usually are associated with facial asymmetry, mental retardation, seizures, and contralateral hemiplegia.
DDMS; Cerebral Hemiatrophy Syndrome.
In 1933, C. G. Dyke, L. M. Davidoff and C. B. Masson first described the syndrome in plain radiographic and pneumoencephalographic changes in a series of nine patients. The syndrome causes cortical and subcortical atrophy, porencephalic cysts, contralateral hemiparesis, infarction, and gliosis of middle cerebral artery with compensatory hypertrophy of skull and sinuses.
The exact incidence remains unknown. Only a small series of case reports has been published since the first description in 1933.
Unknown. Normal chromosomal karyotypes and amino acid excretion patterns on testing. Males and females are equally affected.
Condition results from two different etiologies.
Primary: Caused by perinatal asphyxia with symptoms apparent soon after birth and often resulting in severe white matter lesions and marked asymmetry of the pyramidal tracts.
Secondary: Caused by loss of cortical neurons with symptoms presenting later in childhood after a generally normal early development. Syndrome may be postictal, particularly if there is a history of early childhood febrile seizures (multifocal neuronal loss) following a vascular insult such as middle cerebral artery stroke or trauma (more focal abnormality).
Clinical suspicion is confirmed by the classic changes on skull radiograph showing ipsilateral osseous hypertrophy of the calvaria and hyperpneumatization of the paranasal sinuses and mastoid cells. This is a result of the failure of brain growth leading to inward growth of bony structures, resulting in increased size of the frontal sinus and elevation of the greater wing of sphenoid and petrous ridge on the affected side. Computed tomography and MRI scans are used to assess the etiology and extent of cerebral parenchymal involvement. They usually reveal dilation of the ventricles and low density of the involved cortical side. Thickening of the calvaria and midline shift are seen in about half of cases. Temporal sclerosis is frequent if there is a history of febrile convulsions.
Asymmetry of the face and calvaria and contralateral hemiplegia are the main characteristics. Moderate-to-severe mental retardation is often associated with cerebral palsy, visual perception problems, language (slurred or immature) or speech problems (repetitive speech patterns, simple jargon), and seizures. Patients may present with symptoms of schizophrenia without neurologic abnormalities. Coarctation of the midthoracic aorta has been reported.
Precautions before anesthesia
General clinical assessment including the ability to cooperate. The presence of facial asymmetry, contralateral atrophy, hemiparesis, and ...