Global Transient Amnesia as the Predominant Symptom of Cardiac Myxoma: A Case Report.

BACKGROUND The most common neurological symptoms from cardiac myxoma-induced stroke include territories of middle cerebral arteries, rendering posterior stroke less common. Although transient global amnesia usually has a benign prognosis, amnesia in the setting of concerning cerebellar symptoms should raise the suspicion for posterior circulation involvement. These benign-appearing symptoms can be manifestations of an acute cerebrovascular accident (CVA). This unusual presentation can delay workup for underlying pathology. CASE REPORT A 67-year-old woman presented to the local emergency department after an episode of global amnesia that lasted about 15 minutes and was associated with some dizziness. The patient also reported a history of chronic disequilibrium. The head CT scan was negative for any acute findings. A follow-up MRI of the brain demonstrated acute small lacunar infarcts within the left cerebellum and right parietal lobe. An echocardiogram was performed due to concern for the cardioembolic source, which revealed left atrial myxoma. She was transferred to a tertiary center for immediate surgical intervention due to the high risk of embolization associated with the condition. The patient subsequently underwent successful surgical excision of the lesion. CONCLUSIONS Cardiac myxoma, although a rare cause of posterior stroke, needs prompt intervention as it is associated with a high risk of systemic embolization, including recurrent CVA. Transient global amnesia is an atypical presentation of cardiac myxoma that can easily be overlooked, delaying timely diagnosis and prompt intervention. Early recognition and surgical resection are crucial to prevent potentially life-threatening consequences.

Long-Term Risk of Stroke After Transient Global Amnesia in Two Prospective Cohorts.

Background and Purpose- Transient global amnesia (TGA) is known as a benign syndrome, but recent data from neuroradiological studies support an ischemic cause in some cases, which might suggest an increased susceptibility to cerebrovascular events. We determined the long-term risk of stroke after a first TGA in 2 independent prospective cohorts. Methods- In 2 independent prospective cohorts of patients with TGA (OXVASC [Oxford Vascular Study], population-based; NU (Northern Umbria) cohort, TGA registry), cardiovascular risk factors and long-term outcomes, including stroke and major cardiovascular events, were identified on follow-up. Cardiovascular risk factors were treated according to primary prevention guidelines. In OXVASC, the age-/sex-adjusted risk of stroke during follow-up was compared with that expected from the rate in the underlying study population. Results- Among 525 patients with TGA (425 NU and 100 OXVASC), mean (SD) age was 65.1 (9.5) years and 42.5% male. Hypertension (58.1%), dyslipidemia (40.4%), and smoking (36.4%) were the most frequent cardiovascular risk factors. The risk of stroke was similar in the 2 cohorts, with a pooled annual risk of 0.6% (95% CI, 0.4-0.9) and a 5-year cumulative risk of 2.7% (1.1-4.3). Moreover, the stroke risk in OXVASC cases was no greater than that expected in the underlying study population (adjusted relative risk=0.73; 0.12-4.54; P=0.74). Conclusions- TGA does not carry an increased risk of stroke, at least when cardiovascular risk factors are treated according to primary prevention guidelines.

Persistência de imagem de hiperintensidade no hipocampo após episódio de amnésia global transitória / Persistence of hyperintensity image in the hippocampus after an episode of transient global amnesia

A patogenia da amnésia global transitória (AGT) continua obscura. Estudos recentes demonstraram que, em alguns pacientes, a sequência de difusão (DWI) da ressonância magnética pode revelar apresença de sinal pequeno e pontual hipersinal no hipocampo, após a fase aguda do episódio. Esse sinal é principalmente visualizado nas primeiras 6 horas do início do evento, sendo 114 horas o tempo máximo que foi registrado até o momento. Estamos apresentando um caso em que essa imagem persistiu por 11 dias após o episódio. Discutem-se as conhecidas causas, as teorias da patogenia da AGT e a possível conexão entre um efeito vascular e a depressão alastrante, como relatada na enxaqueca com aura.

The pathogenesis of transient global amnesia (TGA) remains obscure.Recent studies revealed that small and punctate signal on diffusion-weighted imaging (DWI) in the hippocampus after the post-acute phase. This signal is mainly seen in the first 6 hours of the onset of the event, and so far the maximum time registered was 114 hours. We present one case where this image persisted for 11 days after the episode. Known causes, theories on pathogenesis of TGA and a possible relation between a vascular mechanism and the spreading depression, as reported in migraine with aura, are discussed.