Case Report Cephalic auras of supplementary motor area origin: An ictal MEG and SAM(g 2 ) study Leonides Canuet, Ryouhei Ishii * , Masao Iwase, Ryu Kurimoto, Kouji Ikezawa, Michiyo Azechi, Hidetoshi Takahashi, Takayuki Nakahachi, Masatoshi Takeda Department of Psychiatry, Osaka University Graduate School of Medicine, Suita City, Japan article info Article history: Received 1 April 2008 Revised 16 May 2008 Accepted 19 May 2008 Available online 27 June 2008 Keywords: Cephalic aura Sensory seizure Supplementary motor area Frontal lobe epilepsy Ictal magnetoencephalography Electroencephalography Synthetic aperture magnetometry Kurtosis abstract Although a nonspecific cephalic sensation, the so-called ‘‘cephalic aura,” is a common sensory aura, par- ticularly in frontal lobe seizures, but is rarely is the entire sensory seizure event. The unusual presenta- tion of cephalic sensations in isolation representing supplementary motor area (SMA) seizures, which are commonly unaccompanied by ictal electroencephalography (EEG) changes, can easily lead to misdiagno- sis of nonepileptic psychogenic seizures. We illustrate the case of a 36-year-old male patient with frontal lobe epilepsy who presented with isolated cephalic auras described as a nonvertiginous sense of head movement without observable clinical signs after his habitual partial motor seizures were controlled with pharmacotherapy. Video/EEG recordings showed no recognizable epileptic discharges time-locked to the onset of the isolated cephalic auras. Ictal magnetoencephalography (MEG) with synthetic aperture magnetometry–kurtosis (SAM(g 2 )) analysis demonstrated the SMA onset of the cephalic auras; thus, MEG was essential in differentiating these isolated auras from nonepileptic psychogenic events. Ó 2008 Elsevier Inc. All rights reserved. 1. Introduction Epilepsy aura is considered a subjective ictal phenomenon that in a given patient may precede an observable seizure, but, if occur- ring alone, constitutes a sensory seizure [1]. A nonspecific cephalic sensation, the so-called ‘‘cephalic aura,” is a common sensory aura, particularly in frontal lobe seizures [2,3]. It has been suggested that isolated auras that represent partial seizures and usually have auditory, viscerosensory, or psychic symptoms are a common fea- ture of temporal lobe epilepsy, but not frontal lobe epilepsy (FLE). Thus, many patients with FLE deny auras that do not progress fur- ther. This is particularly true for cephalic auras, which evolve into a dialeptic or motor seizure and rarely constitute the entire sensory seizure event [3]. Despite the general consensus that cephalic auras do not local- ize to a specific area within the frontal lobe, these auras are re- ported in association with the sensorimotor area (SMA) [2,3]. In mesiofrontal epilepsy, including SMA epilepsy, searching for an electroencephalography (EEG) focus is often elusive [4]. Magneto- encephalography (MEG), which provides higher resolution than EEG in the localization of deeply located sources in the brain, ap- pears to be of value in the detection of SMA epileptogenic foci, especially using ictal recordings [5]. However, ictal MEG is rare be- cause of movement artifacts that interfere with accurate source localization and logistic difficulty with prolonged recording in the MEG laboratory; hence, magnetoencephalograms have gener- ally been recorded in patients with intractable or prolonged non- convulsive seizures [6]. We illustrate the case of a patient with FLE who developed isolated cephalic auras, described as a nonver- tiginous sense of head movement, after the habitual partial motor seizures were controlled. Ictal MEG was essential in differentiating the cephalic auras from nonepileptic events and in demonstrating the SMA onset of these sensory seizures. 2. Clinical presentation A 36-year-old, left-handed, male patient began to have seizures at the age of 3 years following viral encephalitis. Seizure frequency was about five or six per year during childhood. Thereafter, the pa- tient experienced good seizure control on carbamazepine, even though a few periods of seizure exacerbation were reported. At the age of 35, the seizures recurred up to several times a day, and the patient was admitted to our hospital. Seizures were char- acterized by abrupt asymmetric tonic posturing of the arms (the right showing greater elevation than the left), often preceded by an aura of nonspecific sensation localized to the head and de- scribed as indefinable. These seizures were typically accompanied by facial grimacing, and followed by head and eye deviation to the right. The seizures were very brief in duration, usually lasting less 1525-5050/$ - see front matter Ó 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2008.05.013 * Corresponding author. Address: Department of Psychiatry, Osaka University Graduate School of Medicine, Yamadaoka 2-2, D-3, Suita City 565-0871, Japan. Fax: +81 6 6879 3059. E-mail address: ishii@psy.med.osaka-u.ac.jp (R. Ishii). Epilepsy & Behavior 13 (2008) 570–574 Contents lists available at ScienceDirect Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh