Daneault et al. Journal of Medical Case Reports 2011, 5:449 http://www.jmedicalcasereports.com/content/5/1/449 C A S E R E P O R T JOURNAL OF MEDICAL CASE REPORTS Open Access Changes in physiological tremor associated with an epileptic seizure: a case report Jean-François Daneault1, Benoit Carignan2, Maxime Robert3 and Christian Duval3* Abstract Introduction: Epileptic seizures are associated with motor, sensory, somatosensory or autonomic symptoms that have all been described in varying detail over the years. Of interest in the present report is a case of normal physiological tremor, which to date has never been evaluated prior to and during an epileptic seizure. In fact, there is only anecdotal mention of pre-ictal and ictal changes in clinically noticeable tremor in the literature. Case presentation: Our patient was a left-handed, 27-year-old Caucasian woman diagnosed seven years previously with partial epileptic seizures, secondarily generalized. Physiological tremor was measured simultaneously on the index finger of both hands of our patient. Electromyography as well as heart rate and respiration were also monitored. A previously performed electroencephalography examination revealed abnormal oscillations focalized to the left primary somatosensory cortex. She was also diagnosed with left frontal neuronal heterotopias. We detected subclinical changes in tremor characteristics, such as amplitude, median power frequency and power dispersion, contralateral to the localization of epileptic activity. Tremor characteristics remained relatively steady ipsilateral to the localization of the epileptic activity. Conclusions: Changes in physiological tremor characteristics should be considered as another possible pre-ictal or ictal manifestation. We propose that the network associated with physiological tremor might be more sensitive to abnormal oscillations generated within the central nervous system by epileptic activity from certain structures. Introduction Epilepsy is characterized by a predisposition to abnor- mal brain activity leading to seizures, as well as motor and non-motor symptoms [1]. In addition to motor, sensory, somatosensory or autonomic symptoms that can be encountered during the ictal phase [2], physiolo- gical changes have also been observed in the pre-ictal phase. In some cases heart rate variability has been shown to increase in the minutes prior to the clinical onset of seizures [3]. There is also anecdotal mention of pre-ictal and ictal changes in clinically noticeable tremor [4]. These manifestations are intimately linked to the localization of the seizure activity. In this report, we describe the case of an epileptic patient who had a sei- zure while physiological tremor (PT) was being recorded. PT is commonly described as involuntary rhythmical oscillations with sinusoidal properties. These * Correspondence: duval.christian@uqam.ca 3Département de Kinanthropologie, Université du Québec à Montréal, Montréal, Québec, Canada Full list of author information is available at the end of the article low-amplitude oscillations, normally less than 0.5 mm [5], stem from mechanical properties of the limb [6] as well as possible central oscillators [7]. The characteris- tics of PT have been extensively studied by our group [8,9] and others (see [10] for review). Case presentation Our patient was tested as part of a study on bilateral PT [8]. She signed the institutionally approved informed consent form, but omitted to inform us of her condition prior to testing. Detailed procedures for that study can be found in the published work [8], and are described in brief below. A medical history for our patient was gath- ered from her medical records. She was a left-handed, 27-year-old Caucasian woman who had been diagnosed seven years previously with partial epileptic seizures, secondarily generalized. Her medical records also described abnormal electroencephalography (EEG) oscil- lations focalized to the left primary somatosensory cor- tex. She was also diagnosed with left frontal neuronal heterotopias. Since her diagnosis, her symptoms had © 2011 Daneault et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.