Somatosensory aura in mesial temporal lobe epilepsy: semiologic characteristics, MRI findings and differential diagnosis with parietal lobe epilepsy

Abstract

INTRODUCTION: Somatosensory auras (SSAs) are more usually described in patients with parietal lobe epilepsy (PLE), producing more commonly a localized cutaneous tingling sensation, involving hands and fingers followed by tonic or clonic focal seizures. These usually originate in the contralateral hemisphere. Etiology includes dysplasias, tumours, ischemic or postencephalitic gliosis. However, other focal epilepsies, such as frontal and temporal, may also originate SSAs. Although this type of aura is reported as rare in patients with mesial temporal lobe epilepsy (MTLE), this association has not been systematically studied. OBJECTIVES: The aim of this article was to describe the cases of four patients with refractory MTLE and SSAs, reporting their clinical characteristics and MRI findings. We discuss the localizing and lateralizing value of SSAs, particularly in the context of MTLE. METHODS AND RESULTS: Four patients with refractory MTLE and SSAs followed-up in the outpatient's clinic at the Epilepsy Section, Universidade Federal de São Paulo, were submitted to presurgical evaluation and corticoamygdalohippocampectomy. MRI in all cases showed unilateral mesial temporal sclerosis (MTS). Regarding seizure semiology, tingling sensation involving the upper extremity was the most prevalent symptom. Three of the four patients had SSAs contralateral to the MTS. Following the SSAs all patients most of the time presented other symptoms such as autonomic or psychic auras evolving to psychomotor seizures. After surgical treatment, two of the patients presented infrequent auras, and two were rendered seizure-free. CONCLUSION: Although rare, SSAs can be present in MTLE. The characteristics of autonomic or psychic auras, psychomotor seizures, neuropsychological deficits, and typical neurophysiologic and MRI findings may help differentiate patients with MTLE from those with PLE.

Somatosensory and Pharyngolaryngeal Auras in Temporal Lobe Epilepsy Surgeries

“…Our findings are in line with previous reports suggesting that SSA [8, 26, 27] and PLA [21, 22] do not necessarily indicate an extratemporal seizure onset or an independent extratemporal seizure focus in patients with pharmacoresistant temporal lobe-like epilepsy. Our findings would suggest that for the majority of our patients, SSA or PLA was the result of rapid spread of epileptic activity to perisylvian somatosensory structures such as the insular cortex and second somatosensory cortex (SII) [1, 2, 5, 6, 22, 26, 35–37] rather than from an extratemporal seizure focus.…”

“…Although some studies have suggested that patients with pharmacoresistant TLE who exhibit SSA and PLA have a favorable prognosis following temporal lobe surgery [8, 21, 26, 27], others have reported a poor outcome in this patient population [28–30]. The purpose of this study was to determine the prevalence and prognostic significance of SSA/PLA as a potential marker of insular epilepsy and thus a predictor of poor response to surgery in TLE patients.…”

Case Report on Epilepsy with Cough Aura

“…Several studies reported that any aura involved with epilepsy was developed mostly in a mesial temporal epilepsy. A study showed that majority of their patients with a mesial temporal epilepsy developed some sort of somatosensory aura mostly in the form of a tingling sensation in the upper extremities [5]. The study based on abdominal aura showed that development of an abdominal aura was more common in patients with temporal lobe epilepsies compared to those patients with an extra temporal epilepsy.…”

Neural Encoding of Acupuncture Needling Sensations: Evidence from a fMRI Study

“…The study using MEG showed that both selective stimulation of A δ -fiber or C-fibers induced the ultra-late evoked brain potentials at posterior parietal cortex [37], which supported our findings in the sensations of pressure, heaviness, and fullness involving A δ -fiber and/or C-fibers. On the other hand, the relationship between the sensations of numbness and tingling and posterior parietal cortex also can be supported by tingling and numbness of limbs commonly found in patients with parietal lobe epilepsy [45, 46]. …”