RESUMO
BACKGROUND: Whether presenting an episode of amaurosis fugax (AFx) increases the risk of ischemic stroke is controversial and there is a lack of consensus in the following management. We aimed to describe the clinical characteristics and prognosis of patients with AFx due to suspected transient retinal ischemia. METHODS: Observational, retrospective study of patients admitted in a Comprehensive Stroke Center with diagnosis of AFx due to suspected transient retinal ischemia between 2015 and 2020. Clinical characteristics and diagnostic-therapeutic data were collected, as well as recurrences (new episodes of amaurosis and/or ischemic strokes). Multivariable Cox regression analyses were performed to study factors associated with the risk of recurrence. RESULTS: We included 91 patients with a mean age of 67.9±14.8 years, 43(47.3%) were women. After the diagnostic workup 14(15.4%) AFx were attributed to an atherothrombotic etiology, 4(4.4%) cardioembolic source, 10(11%) other determined cause (TOAST-OC) and 63(69,2%) indeterminate etiology. 71(78%) patients started antiplatelet therapy and 2(2.2%) anticoagulant therapy. After a median follow-up of 3.5 years (IQR 1.8-5.2), at least one recurrence was recorded in eight (8.8%) patients (four new AFx and four cerebral infarctions). TOAST-OC (HR=9.66, 95% CI 2.41-38.70; p=0.001) and prior history of ischemic stroke (HR=4.21. 95% CI 1.01-17.66; p=0.049) were both independently associated with the risk of recurrence. CONCLUSIONS: In two out of three patients, AFx due to transient retinal ischemia was of undetermined cause. The risk of stroke recurrence after a first episode of AFx in our cohort was 8.8%. Patients with TOAST-OC etiology identified were at highest risk of recurrence.
RESUMO
Background: Magnesium is an important intracellular cation involved in essential enzymatic reactions. It is necessary for neuronal function and its depletion can produce neurological symptoms such as cramps or seizures. Clinical consequences of its deficit in the cerebellum are less known and the diagnosis can be delayed because of the lack of awareness on this condition. Cases: We present three cases of cerebellar syndrome (CS) due to hypomagnesemia: A midline CS with myoclonus and ocular flutter and two cases of hemispheric CS, one of them entailed a Schmahmann's syndrome and the other suffered a seizure. MRI findings revealed cerebellar vasogenic edema and the symptoms improved after magnesium replacement in all cases. Literature Review: We reviewed 22 cases of CS due to hypomagnesemia, all with subacute onset (days to weeks). Encephalopathy and/or epileptic seizures were common. MRI findings were vasogenic edema involving the cerebellar hemispheres, the vermis, or the nodule. Up to 50% of patients presented hypocalcemia and/or hypokalemia. All the patients showed symptomatic improvement after magnesium replacement, but 50% showed significant sequelae, and 46% relapsed. Conclusions: Hypomagnesaemia should always be considered in the differential diagnosis of CS as it has a potential treatment, and its early recognition can avoid recurrences and permanent cerebellar impairment.
