Autopsy reports described prevalent white matter abnormalities and brainstem pathology [36]. The presence of numerous spiny neurons dispersed in the white matter has also been reported, which is suggestive of impaired neuronal migration and apoptosis [20]. Using functional neuroimaging selleck compound library techniques in a patient with early myoclonic encephalopathy, Hirose et al. [46] demonstrated hypoperfusion and hypometabolism
in the basal ganglia and thalami interictally, with ictal hyperperfusion of the basal ganglia, thalami, brainstem, and deep front-parietal cortex. This finding was indicative of dysfunction in these regions, and was thought to suggest a functional deafferentation of the cortex from subcortical structures [46]. A number of familial cases of early myoclonic encephalopathy have been reported [14] and [40], raising the question of whether the disease involves a genetic component. A likely genetically mediated case was reported in association with Schinzel-Giedion syndrome,
a rare genetic multiple malformation disorder [47]. In 2009, early myoclonic encephalopathy was reported in association with CT99021 clinical trial a mutation of the v-erb-a erythroblastic leukemia viral oncogene homologue 4 (ErbB4 gene), which is involved in the migration of interneurons to the cortex [48]. This genetic abnormality is consistent with the persistence of spiny neurons in the white matter on pathologic examination, and of the functional deafferentation described by Hirose et al. [46], both of which seem to indicate impaired neuronal migration to the cortex, suggesting a degree of “cortical isolation” in the brains of these patients [20], [46] and [48]. The diagnosis of both Ohtahara syndrome and early myoclonic Tacrolimus (FK506) encephalopathy is based on a typical clinical picture and associated electroencephalographic findings,
as already described. The prognosis is universally poor. Neuroimaging to assess for structural brain abnormalities is generally recommended in cases of Ohtahara syndrome. Brainstem evoked potentials are occasionally abnormal in both conditions, but normal studies do not exclude the possibility of disease [36]. Only anecdotal evidence supports the use of specific antiepileptic drugs in these conditions. Phenobarbital, valproate, pyridoxine, zonisamide, and benzodiazepines have all demonstrated limited effectiveness in seizure control in Ohtahara syndrome [10] and [49]. Adrenocorticotropic hormone therapy also exerts limited efficacy, and may be particularly beneficial in cases of Ohtahara syndrome that progress to West syndrome [3] and [9]. None of the antiepileptic medications has been effective in treating early myoclonic encephalopathy, nor have alternative methods of seizure management such as adrenocorticotropic hormone therapy, corticosteroids, and pyridoxine.