Neuroimaging and Electroencephalographic Correlation in Patients with Transient Global Amnesia: Clinical Case Series.

Objective. To determine if there is any correlation between the electroencephalographic and neuroimaging findings in patients with Transient Global Amnesia (TGA). Methods: We retrospectively reviewed files of the First Department of Neurology of AHEPA University Hospital, including patients with a clinical diagnosis of TGA. Only patients who had the characteristic high signal in the temporal lobes in the DWI MRI and those who underwent electroencephalographic recording (EEG) were selected. Results: Out of 28 patients, 8 were selected. We found that 6 out of 8 patients (75%) who had imaging findings in DWI, in at least one medial temporal lobe, also had had intermittent slow theta waves on the electroencephalographic recording. Of these 6 patients, 3 (50%) had bilateral EEG findings, 2 patients (33,3%) only had findings on the left hemisphere and 1 (17%) had on the right hemisphere. 3 out of 6 patients (50%) had electroencephalographic dominance on the left, while 2 out of the 6 (33%) had on the right. In 2 patients with imaging findings in DWI no anomalies were demonstrated on EEG. In 3 out of 8 patients, both MRI and EEG findings correlated on the same side, while 1 patient had opposite findings, depending on which hemisphere the EEG anomalies dominated. Conclusions: There is no absolute matching between the DWI MRI and EEG findings in patients with the clinical diagnosis of TGA. However, there is some degree of correlation, when we focus on the focal dominance of the EEG anomalies, although not statistically significant.

Amnesia global transitoria: una entidad infrecuente pero presente en Pediatría / Transient global amnesia: an infrequent entity but present in Pediatrics

Introducción: La amnesia global transitoria es una entidad caracterizada por la aparición súbita de amnesia anterógrada con amnesia retrógrada variable, conservando intacta la memoria inmediata. No asocia otros déficits neurológicos. La recuperación es progresiva en pocas horas, habitualmente menos de 12, aunque suele persistir amnesia del episodio y presentar posteriormente cefalea leve. Caso clínico. Niño de 10 años, sin antecedentes de interés, que consulta en Urgencias por aparición brusca de amnesia retrógrada de las últimas 48 horas, así como incapacidad para la fijación de nueva información. Se mostraba ansioso y desorientado, y repetía la misma pregunta varias veces. La exploración neurológica por lo demás era estrictamente normal y negaba cefalea u otra sintomatología asociada. No antecedente de traumatismo craneoencefálico. Se realiza analítica sanguínea y gasometría venosa, sin alteraciones significativas; tóxicos en orina, negativos; TAC cerebral que descarta patología intracraneal aguda y punción lumbar, que es normal. Ingresa en planta de hospitalización con evolución favorable, con cese espontáneo de la clínica a las 8 horas, permaneciendo amnesia del episodio, con resto de la memoria conservada. Comentarios. La fisiopatología de la amnesia global transitoria no está del todo aclarada, aunque hay trabajos que sugieren un origen vascular de la misma, produciéndose durante estos episodios una hipoperfusión del lóbulo temporal medial. Es una entidad típica de adultos de mediana edad y ancianos siendo excepcional en pediatría. Sin embargo, debemos considerar este diagnóstico ante niños con clínica típica, normalidad de la neuroimagen y resolución espontánea de los síntomas.(AU)

Introduction: Transient global amnesia is an entity characterized by the sudden onset of anterograde amnesia with variable retrograde amnesia, preserving immediate memory intact. It is not associated with other neurological deficits. Recovery is progressive in a few hours, usually less than 12 hours, although amnesia of the episode usually persists and later presents mild headache. Case report. A 10-year-old boy, with no previous history of interest, consulted the emergency department for sudden onset of retrograde amnesia of the last 48 hours, as well as inability to fix new information. He was anxious and disoriented and repeated the same question several times. The neurological examination was otherwise strictly normal, and he denied headache or other associated symptoms. There was no history of cranioencephalic trauma. Blood analysis and venous blood gas analysis were performed, with no significant alterations; urine toxins were negative; brain CAT scan ruled out acute intracranial pathology and lumbar puncture was normal. She was admitted to the hospital ward with favorable evolution, with spontaneous cessation of the clinical symptoms after 8 hours, remaining amnesia of the episode, with the rest of the memory preserved. Comments. The pathophysiology of transient global amnesia has not been fully clarified, although some studies suggest a vascular origin, with hypoperfusion of the medial temporal lobe occurring during these episodes. It is a typical entity of middle-aged and elderly adults, being exceptional in pediatrics. However, we should consider this diagnosis in children with typical clinical symptoms, normal neuroimaging and spontaneous resolution of symptoms.(AU)

[Transient epileptic amnesia-A rare phenomenon in temporal lobe epilepsies]. / Transiente epileptische Amnesie ­ ein seltenes Phänomen bei Temporallappenepilepsien.

BACKGROUND: Transient epileptic amnesia (TEA) is a rare phenomenon in temporal lobe epilepsy that is often unrecognized or misdiagnosed as transient global amnesia (TGA). It is postulated that TEA is due to both ictal and postictal disturbances. Response to antiseizure medication underlines its epileptic nature. In view of the increasing incidence of new-onset epilepsies in old age, an increase in TEA can be expected in the future. OBJECTIVE: Analysis of TEA features in a monocentric case series. MATERIAL AND METHODS: A search in our electronic patient data base yielded 10 patients with TEA out of 7899 patients over a period of 8 years. Clinical and paraclinical features as well as findings of additional examinations were retrospectively collected. Data are given as mean ± SD. RESULTS: All 10 patients were diagnosed with temporal lobe epilepsy. The mean age at manifestation of TEA was 59.1 ± 6.7 years, the diagnosis was made with a delay of 21.9 ± 26.3 months. The TEA lasted on average 56 ± 37 min, and 16 ± 9.9 TEA episodes per year were reported by the patients; out of the 10 patients 6 reported that TEA usually occurred upon awakening. In 9 of 10 patients, there was evidence of typical seizure symptoms or other semiological elements during TEA. Interictal neuropsychological disturbances of temporal functions were seen in 8 of 10 patients and evidence of depressive disorder in 6 of 10 patients. Video EEG recordings revealed epileptiform activity during sleep in 4 patients over the left and in 2 patients over both temporal regions. In 3 patients, magnetic resonance imaging displayed typical alterations of the temporomesial structures (in 2 patients on the left and in 1 the right side). Antiseizure medication improved seizure control in 7 of 10 patients (seizure freedom in 6 patients), 3 patients were lost to follow-up. DISCUSSION: TEA is rare, occurs in older adults and is correctly diagnosed after about 2 years. Thorough assessment of additional symptoms and circumstances, the recurrent occurrence as well as typical EEG and imaging findings of temporal lobe epilepsy enables the distinction between TEA and TGA.

Transient global amnesia with transient anosmia: a curious case suggestive of middle cerebral artery occlusion.

BACKGROUND: Transient global amnesia (TGA) is an enigmatic amnestic syndrome and affects people in middle or older age. During an episode of TGA, a person is not able to make new memories, which indicates hippocampal damage. The symptom anosmia may be associated with memory impairment. CASE PRESENTATION: A 70-year-old woman presented to our emergency room with transient spatial memory loss. She also complained of a sudden loss of smell. Magnetic resonance angiography confirmed occlusion of the right middle cerebral artery. DISCUSSION AND CONCLUSION: The mechanism causing the transient anosmia may have resulted in a transient loss of hippocampal function, resulting in amnesia. This rare case is consistent with recent research showing that olfaction has developed as a navigation system.

New-Onset Transient Global Amnesia: A Clinical Challenge in an Air Medical Transportation Pilot With a History of Coronavirus Disease 2019.

A 43-year-old male Bell 214C helicopter pilot presented to the emergency ward with flu-like syndrome. His nasopharyngeal severe acute respiratory syndrome coronavirus 2 real-time polymerase chain reaction test was positive, and a chest computed tomographic scan confirmed coronavirus disease 2019 pneumonia. He was admitted, received treatment, was discharged, and returned to flying. During the mission debrief, copilots who had flown with him reported that he experienced episodes of in-flight dizziness and blacked out. They occurred briefly during the cruise and hovering flight, perhaps for a few seconds of disorientation and unconsciousness. Rapid identification of the copilot and control of the helicopter prevented any incident or accident. Afterward, he explained the sudden onset and unexpected brief periods of loss of consciousness after a headache. The flight safety office referred him to the aviation medical center for further investigations. The cardiovascular, neurologic, laboratory, and toxicologic assessments were inconclusive with the approach to sudden-onset transient loss of consciousness. The only abnormal finding was hippocampus lesions on brain magnetic resonance imaging (MRI). Because of the possible diagnosis of transient global amnesia, the aviation medical examiner suspended him from flight duties until complete recovery and the absence of any probable complications.

[Memory Loss - a Case of Sudden Amnesia]. / Herr B. kann sich nicht mehr erinnern ­ wenn das Gedächtnis gelöscht ist.

Memory Loss - a Case of Sudden Amnesia Abstract. Transient global amnesia (TGA) is a clinical diagnosis with typical signs of an anterograde and retrograde amnesia. The underlying mechanisms are yet unknown, different hypotheses are being discussed. Ultimately there is a temporary dysfunction of the hippocampi. Consistent with this, transient uni- or bilateral punctiform hyperintense lesions may be found on DWI-MRI sequences, usually without correlation on FLAIR-weighthed MR-images. Symptoms usually resolve within twenty-four hours. There is no need for a specific therapy. A prophylactic therapy, such as antithrombotic treatment, is not indicated. The prognosis is usually good, the risk of a recurrence is about 18%.

Transient Global Amnesia.

Transient global amnesia (TGA) is a clinical syndrome characterized by anterograde amnesia, mild retrograde amnesia, and confusion up to 24 hours. Most commonly seen in patients older than 50 years, TGA results from the temporary impairment of short-term memory formation. Clinically, patients have time disorientation and often ask repeated questions regarding the day's events. Vomiting, headache, blurry vision, dizziness, and nausea may be present. A physically or psychologically stressful precipitating event, such as emotional stress, significant physical exertion, exposure to extreme temperatures, high-altitude conditions, Valsalva maneuver, acute illness, or sexual intercourse, is often the cause. The pathophysiology of TGA is not well understood but may be related to impaired venous drainage of the hippocampus. The diagnosis is primarily clinical, but recent studies suggest that magnetic resonance imaging may be helpful. TGA is self-limited and resolves within 24 hours. There is no established treatment for episodes. The lifetime recurrence rate is 2.9% to 23.8%. Recent evidence suggests an association between TGA and migraine headaches as well as takotsubo cardiomyopathy. No apparent increased risk of cerebrovascular events occurs in patients who have had an episode of TGA. There is conflicting evidence as to whether an episode of TGA predisposes to future seizures or dementia.