Subclinical rhythmic electrographic discharges of adults and transient global amnesia: a causal or casual association? (original) (raw)
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Left dominance of EEG abnormalities in patients with transient global amnesia
Seizure, 2014
Transient global amnesia (TGA) is characterized by development of acute anterograde amnesia without loss of consciousness, lasting less than 24 h. Poser and Ziegler described seven cases with temporary amnesia as a manifestation of cerebrovascular insufficiency in 1960, 1 and one of these cases had EEG abnormalities without a detailed description. Fisher and Adams, who used the term of TGA for the first time in 1964 to describe typical amnesia, 2 found EEG abnormalities in five out of thirteen patients and bilateral focal spikes or sharp waves in two out of five patients. Since then, the EEG abnormality rate in TGA has been reported to be up to 76.9% 3 but some studies found no EEG abnormalities. 4-7 The exact etiology and mechanism of TGA are still unknown, 8-11 but epilepsy is thought to be a possible mechanism for TGA like ischemia, migraine, and venous insufficiency. TGA has often been focused on DWI or SPECT images during the acute episode. EEG results in patients with TGA are inconsistent and there are few systematic large-scale studies. In this study, we consecutively collected EEGs of total 217 patients with TGA and analyzed the frequency and characteristics of EEG abnormalities in patients with TGA. 2. Methods 2.1. Subjects We retrospectively collected medical records of patients who had visited the emergency room or the outpatient clinic of our hospital from 2003 to 2011 and had been diagnosed as having TGA according to the Hodges & Warlow criteria. 5 Anterograde amnesia Seizure 23 (2014) 825-829
Clinical Outcome of Patients with SREDA (Subclinical Rhythmic EEG Discharge of Adults)
Internal Medicine, 2006
Objective To clarify the clinical significance of 'subclinical rhythmic EEG discharge of adults' (SREDA) by analyzing characteristics of SREDA and the outcome of patients based on retrospective analysis of EEG data base. Methods EEGs were recorded soon after the onset of patient's initial symptoms and repeatedly recorded at various intervals of 2-3 months in all 4 patients. Neurological findings, MRI and SPECT were also investigated. Subjects Out of 340 consecutive inpatient population who had EEGs, 4 patients (1.2%) showed SREDA. They had a diagnosis of syncope, transient global amnesia, generalized tonic-clonic seizure and right temporal lobe epilepsy for each. Results There was no consistent abnormality in the brain MRI, CT or SPECT among the 4 patients. The acute and transient symptoms disappeared and did not recur within the follow-up period of 28 months in any patient. In 2 patients SREDA disappeared in the follow-up EEG taken 7-14 days after the first EEG showing SREDA. In the other 2 patients, the follow-up EEGs taken 5 days after the first EEG with SREDA when clinical symptoms disappeared showed less frequent occurrence of SREDA. Conclusion Being different from the previous reports suggesting the relation with cardiogenic insults or persistent ischemic abnormality, SREDA can occur in patients with various acute brain dysfunctions followed by a favorable clinical outcome.
Brain : a journal of neurology, 2006
Since the first reports of transient global amnesia (TGA) were published in 1956, several neuropsychological and functional imaging studies have shed light on different aspects of this neurological syndrome. By establishing diagnostic criteria, Hodges and Warlow (1990b) have made it far easier to identify clinical TGA-related features. However, no comprehensive survey has been yet carried out in order to validate their criteria/findings or provide information about previously unknown features. In the present paper, (i) we review the literature published since Hodges and Warlow's study and seek to characterize the demographic and clinical features of TGA more accurately, (ii) we report 142 personal TGA cases, with supplementary information regarding both episodes and patients, such as precipitating events, associated symptoms and personality, and (iii) we suggest the existence of different groups of TGA patients, on the basis of a hierarchical cluster analysis. This revealed that...
Are brief or recurrent transient global amnesias of epileptic origin?
Journal of Neurology, Neurosurgery, and Psychiatry, 1994
To evaluate if short (less than one hour) or recurrent, or both, episodes of transient global amnesia (TGA) have an epileptic origin or carry a subsequent risk of epilepsy a group of patients with these types of TGA attacks was studied. The group was selected from a prospective series of 103 patients with TGA. Sixteen patients had an episode lasting less than one hour, 13 had more than one episode, and five patients had both short and recurrent attacks. For each patient the number of recurrences was small (four or less) and they were separated by months or years. During short attacks of TGA many subjects showed other typical features of TGA including repeated questioning (12 subjects) and performance of purposeful complex acts (eight subjects). Twelve short attacks were closely related to a characteristic precipitating event. During follow up only one patient had a seizure (partial motor). No other association between either short or repeated attacks of TGA and past history of epilepsy or paroxysmal discharges were seen on the EEG. Short or recurrent, or both, attacks of TGA are not epileptic and do not carry a relevant risk of subsequent seizures.
Abnormal EEG Power Spectra in Acute Transient Global Amnesia: A Quantitative EEG Study
Clinical EEG and neuroscience, 2018
Transient global amnesia (TGA) is a clinical syndrome characterized by retrograde and anterograde amnesia without other neurological deficits. Although electroencephalography (EEG) methods are commonly used in both clinical and research setting with TGA patients, few studies have investigated neurophysiological pattern in TGA using quantitative EEG (qEEG). The main aim of the present study was to extend these previous findings by exploring EEG power spectra differences between patients with acute TGA and healthy controls using the exact low-resolution brain electromagnetic tomography software (eLORETA). EEG was recorded during 5 minutes of resting state. Sixteen patients (mean age: 66.81 ± 7.94 years) during acute TGA and 16 healthy subjects were enrolled. All patients showed hippocampal or parahippocampal signal abnormalities in diffusion-weighted magnetic resonance imaging performed from 2 to 5 days after the onset of TGA. Compared with healthy controls, TGA patients showed a decr...
Subclinical Rhythmic Electrographic Discharges of Adults in a Patient with Migraine
Clinical EEG and Neuroscience, 2012
Subclinical rhythmic electrographic discharges of adults (SREDA) is an uncommon distinctive EEG rhythmic pattern with uncertain significance. We report a patient with transient global amnesia in whom an EEG recording, performed after the acute phase of the neurological event, showed SREDA. Based on this EEG finding, we discuss about a possible correlation between SREDA and transient global amnesia. The presence of SREDA in our patient with transient global amnesia seems to be incidental. When described in association with transient global amnesia, SREDA should be recognized in order to avoid misdiagnosis. Although SREDA has been fortuitously described in association with transient global amnesia, a patho-physiological correlation with mechanisms which produce it seems unlikely.
Transient Global Amnesia: A Case Report
Case Reports in Neurology, 2012
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Neuropsychology review, 2015
Transient global amnesia (TGA) is a neurological syndrome that usually occurs in middle-aged or older people. It is characterized by the abrupt onset of profound anterograde amnesia, associated with more variable retrograde amnesia and repetitive questioning. The whole episode lasts no more than 24 h. Almost 60 years after its first descriptions, the etiology of TGA remains unknown. Until now, TGA has been described exclusively as a memory disorder, but there is a growing body of evidence to show that emotional and psychological factors (as anxious and depressive symptoms) are present at different times of TGA. Their role therefore needs to be clarified. First, these factors seem to play a part in triggering TGA, at least for a subgroup of patients, suggesting the existence of an emotional TGA subtype. Second, recent research shows that almost all the TGA patients displayed modifications of their emotional state during the episode, possibly linked to sudden memory loss. The level of...
Time trends, frequency, characteristics and prognosis of short‐duration transient global amnesia
European Journal of Neurology, 2020
Background and purposeTransient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia lasting up to 24 h. One major differential for TGA is transient epileptic amnesia, which typically lasts < 1 h. However, TGA can also be short in duration and little is known about the time trends, characteristics and prognosis of TGA cases lasting < 1 h.MethodsWe compared the clinical features of TGA ascertained in two independent cohort studies in Oxfordshire, UK [Oxford cohort 1977–1987 versus Oxford Vascular Study (OXVASC) 2002–2018] to determine the time trends of clinical features of TGA. Results were validated in another independent contemporary TGA cohort in Italy [Northern Umbria TGA registry (NU) 2002–2018]. We compared the risk factors, clinical features and long‐term prognosis (major cardiovascular events, recurrent TGA and seizure/epilepsy) of patients presenting with episodes lasting < 1 h versus those lasting ≥ 1 h.ResultsOverall, 639 patients with T...