EEG findings during "paroxysmal hemiplegia" in a patient with GLUT1-deficiency

A growing number of studies have disclosed the myriad of features that can suggest the diagnosis of a Glucose-transporter-1 deficiency (GLUT1D). The occurrence of paroxysmal movement disorders such as exercise-induced dystonia and non-kinesigenic dyskinesia, received considerable emphasis, while limited attention has been paid to other paroxysmal phenomena, as transitory neurological disorders. These paroxysmal events are roughly and variably described as limb weakness, hemiparesis or ataxia. Their EEG correlate has been never documented.

We report the EEG pattern characterizing two acute episodes of paroxysmal paresis with confusion and aphasia, in a girl with GLUT1D. The EEG picture is characterized by a clear-cut contralateral EEG slowing, similar to what is observed in Alternating Hemiplegia of Childhood and Hemiplegic Migraine attacks. In our patient the paroxysmal events were responsive to a ketogenic diet.