Neurovascular microdysgenesis in a case of Unverricht-Lundborg's disease

An 18 year old female presented with a characteristic clinical course of Unverricht-Lundborg's disease. She was treated with several antiepileptic drugs but never with phenytoin. This patient died quietly during sleep. Coronal sectioning of the fixed brain revealed a 10 mm large red-brown solid cortical-subcortical lesion in the mesial part of the right frontal lobe and a similar alteration measuring 4 mm in the centromedian nucleus of the left thalamus. Histologically the lesions displayed supernumerary irregularly oriented vessels, mainly capillaries, and, in the cortex, a markedly disturbed neuronal orientation and lamination. Numerous heterotopic nerve cells were found in the subcortical white matter, especially under the calcarine cortex. A similar vascular malformation was found in the pons. The neuropathological changes in Unverricht-Lundborg's disease have been described as non-specific atrophy of various neuronal populations, especially medial thalamic nuclei and Purkinje cells. The present case shows that the same clinical picture may be associated with multiple cerebral microvascular malformations and a disturbance in neuronal migration and organization which may be more generalized than appears in light microscopical sections.