|Year : 2019 | Volume
| Issue : 2 | Page : 180-182
Isolated epileptic nystagmus
Shalesh Rohatgi, Satish P Nirhale, Pravin Naphade, Prajwal Rao, Khadkikar Gajanan
Department of Neurology, Dr. DY Patil Medical College, Hospital and Research Center, Dr. DY Patil Vidyapeeth, Pune, Maharashtra, India
|Date of Submission||21-Jun-2018|
|Date of Acceptance||28-Aug-2018|
|Date of Web Publication||25-Mar-2019|
Department of Neurology, Dr. DY Patil Medical College, Hospital and Research Center, Dr. DY Patil Vidyapeeth, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Isolated epileptic nystagmus is defined as a quick, repetitive jerky movement of the eyeball associated with seizure activity on electroencephalography. However, there are no clinical seizures apart from nystagmus. We report a case of 56-year-old male, not a known case of diabetes or hypertension, nonsmoker, who presented with frequent episodes of dizziness along with difficulty in reading in that the lines in newspapers were moving side to side. He was conscious during episodes. He was found to have episodes of gaze deviation to the left with left beating nystagmus lasting for about 30 s. Routine hematological and biochemical parameters were normal. Electroencephalogram showed right parieto-temporo-occipital epileptogenic activity. Magnetic resonance imaging (MRI) brain showed diffusion restriction in the right temporo-occipital region suggestive of small ischemic infarct. Repeat MRI after 1 month was normal. He responded to levetiracetam.
Keywords: Epileptic nystagmus, isolated epileptic nyystagmus, nystagmus
|How to cite this article:|
Rohatgi S, Nirhale SP, Naphade P, Rao P, Gajanan K. Isolated epileptic nystagmus. Med J DY Patil Vidyapeeth 2019;12:180-2
| Introduction|| |
Isolated epileptic nystagmus (IEN) is defined as a quick, repetitive jerky movement of the eyeball associated with seizure activity on electroencephalography. However, there are no clinical seizures apart from nystagmus.
A number of different cortical regions could induce IEN. However, cases of IEN due to ictal discharge from the posterior temporoparietal-occipital region or occipital lobe have been reported.
The nystagmus can be accompanied with vertigo when the epileptogenic focus is in cortical saccade region (including the frontal eye field, supplementary eye field, parietal eye field, and posterior parietal lobule) and parietoinsular vestibular cortex.
Gaze deviation, blindness, or eye blinking have also been reported along with nystagmus.
IEN could be classified as two types according to their pathophysiologic mechanisms. In Type I, the epileptogenic focus is in cortical saccade region and produces nystagmus with a contralateral fast component. In Type II, the Brodmann area 19/37/39 is involved in nystagmus with an ipsilateral slow component. Nicita et al. showed a strong correlation of electroencephalogram (EEG) findings with active foci during the ictal phase in single-photon emission computed tomography (SPECT) images. Many patients with EN have brain lesions such as hemorrhage, tumor, or cortical dysplasia.
| Case Report|| |
A 56-year-old male, not a known diabetic or hypertensive, nonsmoker presented with complaints of difficulty in reading newspapers with attacks of dizziness for 15 days, in that while reading newspapers, he found that the lines were moving side to side. Such episodes lasted for few seconds and occurred every 5–10 min throughout the day. Onset was abrupt. There was no history of loss of awareness, deviation of head, or any tonic clonic movements. He was conscious throughout the episodes. There was no history of head injury, fever, or any other neurological symptoms. Clinical examination showed episodes of the left gaze deviation with left beating nystagmus lasting for about 30 s. There was associated lightheadedness but no true vertigo. He was fully conscious during the episodes. There was no neurological deficit. Head impulse test and Dix–Hallpike test were negative. Hematological and biochemical parameters including blood sugar, glycated hemoglobin, and lipid profile were normal. EEG showed epileptogenic activity in the right parieto-temporo-occipital region [Figure 1]. Magnetic resonance imaging (MRI) brain showed diffusion restriction in the right temporo-occipital region, thought to be ischemic infarct [Figure 2] and [Figure 3]. MR angiography of the brain, carotid Doppler, and two-dimensional echocardiography were normal. Repeat MRI after 1 month was normal [Figure 4] and [Figure 5]. The patient was treated with levetiracetam with very good clinical response.
|Figure 1: Electroencephalogram showing epileptogenic activity in the right parieto-temporo- occipital region|
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|Figure 2: Diffusion-weighted imaging showing hyperintensity in the right temporo-occipital region|
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|Figure 3: Apparent diffusion coefficient image showing diffusion restriction corresponding to diffusion-weighted imaging|
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|Figure 4: Repeat diffusion-weighted imaging after 1 month showing no abnormality|
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| Discussion|| |
In a systemic review of 36 patients, Lee et al. found that in almost all of the patients, the nystagmus was contralateral to epileptogenic focus and seizures mostly originated from the posterior part of the brain.
In our patient, we had evidence of the right parieto-temporo-occipital epileptogenic activity. The initial MRI showed diffusion restriction in that region and suggested acute ischemic infarct. The findings normalized after 1 month.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]