[Effect of blink reflex in diagnosis of central vertigo and its comparison with brain MRI]

Vestibulitis and VIII nerve lesions are the final diagnosis in most of the patients presenting with acute true vertigo, but central vertigo due to brainstem lesions must always be considered. In most of the patients, brain MRI is the only available solution. In this study, blink reflex [BR] abnormalities in acute true vertigo were compared with MRI findings. One hundred and five patients who were presented with acute true vertigo without other signs of brainstem involvement, and who had normal neurologic examination were evaluated. In 18 patients in whom new neurologic signs were appeared or their symptoms were lasted for more than 72 hr, BR and brain MRI were requested and their results were compared. From 18 patients, in 5 patients BR and brain MRI were normal and central vertigo was ruled out. In 8 patients both BR and brain MRI were abnormal. Three patients had normal BR and abnormal brain MRI. In the last two patients, brain MRI was normal but BR was abnormal. Abnormal response of BR [76.9%] were well correlated with abnormal MRI findings [84.6%], and the results of the two tests were additive. Therefore, BR can be a good accompaniment for brain MRI in evaluation of central vertigo. Based on low practice of mothers, it is recommended to give necessary knowledge to mothers by regular educational program and make them sure that fluid therapy is effective. Therefore, they can learn necessary skills to prevent mortality of children due to dehydration

[Comparing MRI findings and blink reflex in patients with brainstem strokes]

Introduction: Blink Reflex [BR] is an electro diagnostic test, which is equivalent to the corneal reflex. BR responses are classified as R1, R2 and R2c. Abnormalities of these responses have been reported in brainstem lesions

Objective: This article aims to survey diagnosis of brainstem strokes by BR in comparison to MRI findings

Materials and Methods: Twenty-two brainstem stroke patients were evaluated. Brain MRI and BR were obtained within the first 48 hours in all of them. Ten control cases of similar age and sex were enrolled to the study for determination of normal and abnormal range of BR responses. At last MRI finding were compared with BR responses

Results: from the total of 22 patients, MRI did 21 correct diagnosis of brainstem and BR did 20. BR correctly diagnosed one case, not diagnosed by MRI, and two cases with normal BR was diagnosed by MRI BR responses were also analyzed in midbrain, pons, modullary and cerebella lesions. Brain MRI and BR were successful in diagnosis of the brainstem lesions in 95.4% and 90.9% cases respectively, and each test revealed some cases unidentified by other method

Conclusion: In diagnosis of brainstem lesions, it is better to use clinical findings, MRI and electrophysiological tests together. This policy can minimized the undiagnosed fraction of brainstem stroke and may prevent a catastrophic outcome

Blink reflex as a complementary test to MRI in early detection of brainstem infarctions: comparison of blink reflex abnormalities in anterior versus posterior circulation strokes

Background: early detection of vertebro-basilar insufficiency is of paramount importance. Brain MRI was the only method of diagnosis for many years, but in addition to high cost and delay in report, it may not detect all brain stem lesions. In this study Blink reflex [BR] was evaluated as a complementary test to MRI

Methods: fifty-four patients were studied [27 anterior circulation stroke patients [ACSP] and 27 posterior circulation stroke patients [PCSP]]. MRI was performed within the first week after the onset of stroke. Nineteen age and sex matched healthy people enrolled as controls. BR was performed within the first 24 hours of the onset. Frequency of abnormal blink reflex in ACSP and PCSP was compared with MRI findings. Then abnormal responses in two groups were compared by chi-square test

Results: in both ACSP and PCSP, two patients had normal BR responses, and in 25 patients R1 or R2 components of blink responses were absent or prolonged [92.5%]. R1was absent or delayed in 16 PCSP, but it was abnormal in only two ACSP [P < 0.001]. Abnormal R2 responses were detected in 22 PCSP and 24 ACSP

Conclusion: BR abnormalities had high correlation with MRI findings in PCSP [92.5%] BR can be performed within the first 24 hours of onset of stroke, and its results is available immediately. This test is easy to perform and comfortable for the patient, has low cost, and is available every where. Therefore we introduced BR as a complementary [but not replacing] test to MRI in early detection of brainstem infarctions. Comparison of BR responses in ACSP and PCSP showed that abnormalities of R1 responses had high accuracy in differentiation between anterior and posterior circulation strokes. We concluded that BR responses not only can detect brainstem infarctions rapidly and readily in its early stages, but also can differentiate ACSP from PCSP with high accuracy