Are personality traits of juvenile myoclonic epilepsy related to frontal lobe dysfunctions? A proton MRS study

Abstract

SUMMARYPurpose: Personality traits characterized by emotional instability and immaturity, unsteadiness, lack of discipline, hedonism, frequent and rapid mood changes, and indifference toward one's disease have been associated with patients who have juvenile myoclonic epilepsy (JME). Literature data demonstrate worse seizure control and more psychosocial dysfunctions among patients with JME who have those traits. In this controlled study we performed a correlation analysis of psychiatric scores with magnetic resonance spectroscopy (MRS) values across JME patients, aiming to verify the existence of a possible relation between frontal lobe dysfunction and the prevalence of personality disorders (PDs) in JME. Methods: Sixteen JME patients with cluster B PDs, 41 JME patients without any psychiatric disorder, and 30 healthy controls were submitted to a psychiatric evaluation and to a quantitative multivoxel MRS of thalamus; insula; cingulate gyrus; striatum; and frontal, parietal, and occipital lobes. Groups were homogeneous according to age, gender, and manual dominance. Psychiatric evaluation was performed through the Scheduled Clinical Interview for DSM-IV, Axis I and II (SCID I and II, respectively). Results: A significant reduction of N-acetyl-aspartate over creatinine (NAA/Cr) ratio was observed mainly in the left frontal lobe in the JME and PD group. In addition, a significant increase in the glutamate-glutamine over creatinine GLX/Cr ratio was also observed in this referred region in the same group. Discussion: These data support the hypothesis that PDs in JME could represent neuronal dysfunction and possibly a more severe form of this epileptic syndrome.

Frontal and thalamic changes of GABA concentration indicate dysfunction of thalamofrontal networks in juvenile myoclonic epilepsy

“…In accordance with our study results, frontal Glx increase was also found in the subgroup of seven JME patients . Another study found a frontal Glx/Cr increase together with NAA/Cr decrease in JME patients with personality disorders, supporting the hypothesis that typical personality changes of JME patients are related to the frontal lobe dysfunction …”

“…However, glutamine and glutamate are not easily quantifiable at field strengths below 4 Tesla when their overlapping peaks start to separate and GABA measurement requires additional editing. In contrast, the neuronal marker N ‐acetyl aspartate‐glutamate (NAA) is quantifiable even at lower field strengths, and reduced NAA was observed in brain structures that are involved in epilepsy . Only few studies measured in vivo concentrations of GABA or glutamate and glutamine separately (Glx as sum of both, Glx) in patients with JME .…”

Structural and functional correlates of epileptogenesis — Does gender matter?

“…They are characterized by an increase in the concentration of gray matter and thickness of the cortex (Betting et al, 2006; Vulliemoz et al, 2011), along with reductions in N-acetyl aspartate (Savic et al, 2004) and increases in glutamate (de Araujo Filho et al, 2009; Simister et al, 2003). A recent study also reported a significant increase in cortical thickness in the precentral gyrus (Alhusaini et al, 2013).…”

Sex‐specific behavioral traits in the Brd2 mouse model of juvenile myoclonic epilepsy

“…Patients with JME also show less self‐control than matched healthy subjects (Plattner et al ). Magnetic resonance spectroscopy and imaging studies suggest the involvement of prefrontal cortex in these epilepsy patients, and impairments in the prefrontal cortex may also be involved in associated behavioral traits (de Araujo Filho et al ,; Koepp et al ; Piazzini et al ). On the other hand, JME patients usually do not have serious cognitive deficits (Moschetta & Valente ), although JME has been reported to be associated with verbal and visual memory deficits (Sonmez et al ) related to the frontal lobe (Koepp ; Piazzini et al ).…”