A case-control proton magnetic resonance spectroscopy study confirms cerebellar dysfunction in benign adult familial myoclonic epilepsy

Abstract

Background: Benign adult familial myoclonic epilepsy (BAFME) is a rare form of epilepsy syndrome. The pathogenesis of BAFME remains unclear, though it seems to involve dysfunction of the cerebellum.

Objectives: The purpose of this study was to use proton magnetic resonance spectroscopy ((1)H-MRS) to investigate whether neurochemical changes underlie abnormal brain function in BAFME.

Methods: Twelve BAFME patients from one family and 12 age- and sex-matched healthy controls were enrolled in this study. The ratios of NAA/Cr, NAA/Cho, Cho/Cr, and NAA/(Cr+Cho) were analyzed.

Results: The BAFME patients exhibited a decreased N-acetylaspartate (NAA)/choline (Cho) ratio in the cerebellar cortex, whereas there were no significant differences in the NAA/creatine (Cr), Cho/Cr, and NAA/(Cr+Cho) ratios compared with healthy controls. There were no significant differences in (1)H-MRS values in the frontal cortex or thalamus between the BAFME patients and controls. No correlation was detected between the NAA/Cho ratio in the cerebellar cortex and disease duration, myoclonus severity, or tremor severity.

Conclusion: Our results indicate clear cerebellar dysfunction in BAFME. (1)H-MRS is a useful tool for the diagnosis of BAFME in combination with family history and electrophysiological examination.

Keywords: benign adult familial myoclonic epilepsy (BAFME); cerebellum; cortical tremor; myoclonus; proton magnetic resonance spectroscopy (1H-MRS).

Figure 1

Typical spectroscopic localization of VOIs from a single subject. Notes: Transverse, coronal, and sagittal slices are shown from top to bottom. VOIs: (A) left frontal cortex (18×18×20 mm), (B) left thalamus (18×18×20 mm), and (C) left cerebellar cortex (20×20×20 mm). Abbreviation: VOIs, volumes of interest.

Figure 2

Sample of chemical shift imaging spectra from a subject. Notes: Peak NAA, Cr, and Cho were determined at 2.02, 3.02, 3.22 ppm, respectively. Abbreviations: Cho, choline; Cr, creatine; NAA, N-acetylaspartate.