Dyke-Davidoff-Mason Syndrome

A 2-year-old boy with epileptic status associated with fever of unknown origin, which required barbituric induced coma to control it. He remained on ventilatory support during 16 days after which convulsive episodes ceased with anticonvulsive medications.

A CT scan (not shown) reporting brain interstitial oedema was obtained. She was discharged after 30 days, achieving adequate seizure control for 6 months. After this period, she started having atonic generalized seizures as well as right hemiparesis affecting the upper limb predominantly. 

A brain MRI was then performed.

MRI showed left cerebral hemisphere cortical and subcortical volume decrease, which was compensated by subarachnoid and supratentorial ventricular system enlargement (figure 1); Left thalamus and cerebral peduncle showed size reduction as well (figures 2,3); ipsilateral calvarial thickening was present as well. There was also decrease in size of the branches of the left middle and posterior cerebral arteries (figure 4).

Additional findings were enlargement of both the cisterna magna (figure 5) and the left maxillary sinus (when compared to the contralateral).

Dyke-Davidoff-Masson Syndrome is a rare neurological condition. Because the available information comes mainly from case reports, the prevalence of the disease is unknown[1,2]. Most affected patients are paediatrics; however, there are reported cases of adults [3].

The classic imaging features are cerebral hemispheric atrophy, hemi-cranial thickening and hyper-pneumatization of the frontal sinuses (only if the initial insult happens before 3 years old) [4].

Other manifestations are mega-cisterna magna, corpus callosum dysgenesis, unilateral cerebellar peduncle volume decrease, enlargement of the lateral ventricle and the subarachnoid space of the affected side, and decrease in vascularity of the affecter cerebral hemisphere [5, 6].  

Presentation can be congenital or acquired. The congenial variety usually results from perinatal infections, aortic coarctation and vascular neonatal or prenatal occlusion involving the middle cerebral artery. Acquired presentation is preceded by trauma, infection, ischemia, neoplastic process, haemorrhage or prolonged epileptic status [6].

Hemispherectomy the treatment of choice in patients with hemiplegia and intractable disabling seizures; success rates reach 85%. If hemiparesis occurs before 2 years of age, prognosis in poor [7].

Our patient presented prolonged epileptic status which could be the insult that triggered the syndrome. This must be considered since the CT scan performed initially showed no features of the syndrome. However, this can’t be confirmed since there have been cases where the features of the disease are initially missed, particularly when not evaluated by a neuroradiologist.

Conclusion

Dyke-Davidoff-Masson syndrome can be easily missed on imaging due to its low prevalence. Both CT and MRI are adequate to demonstrate the features associated with the syndrome. Knowing the clinical presentation, risk factors and imaging findings are essential to establish the appropriate management of these patients.

Written informed patient consent for publication has been obtained.