Conjugate Eye Deviation in Unilateral Lateral Medullary Infarction

Dynamic changes of the direction and angle of radiographic ocular lateral deviation in patients with lateropulsion after stroke onset

OBJECTIVE

To examine if radiographic ocular lateral deviation (rOLD) could be provoked in stroke patients with mild-to-moderate lateropulsion according to vertical perception.

METHODS

In this single-center, retrospective study, acute stroke patients with mild-to-moderate lateropulsion assessed by the Scale for Contraversive Pushing were enrolled. Computed tomography or magnetic resonance imaging was performed on all patients on admission and then according to their conditions. The direction and angle of rOLD were compared among three groups according to the responsible lesion: lateral medullary (LM), pontine (P), and hemispheric (H).

RESULTS

Sixty-six patients (male, 47; average age, 67 years) were enrolled and divided into the LM (n = 37), P (n = 8), and H (n = 21) groups. All patients had body tilt. Patients in the LM group showed body tilt to the ipsilesional side during hospitalization, while those in the P and H groups tilted to the contralesional side. All patients had rOLD at the final assessment at an average of 13 days after onset; patients in the P and H groups showed contralateral rOLD, while those in the LM group showed ipsilateral rOLD if they did not have cerebellar or pontine lesions. Significant decreases in the angle and changes in direction of rOLD according to lesion site were observed during hospitalization.

CONCLUSION

Serial changes in rOLD findings after stroke onset are different according to the responsible lesion. The direction of rOLD in most patients is in accordance with vertical perception after the acute stage of stroke.

Ocular lateral deviation as a vestibular sign to improve detection of posterior circulation strokes: A review of the literature

BACKGROUND

Posterior circulation stroke can present with dizziness/vertigo without other general neurological symptoms or signs, making it difficult to detect, and missed stroke can deteriorate. Therefore, a sign that can be easily identified during an examination would be helpful to improve the detection of this type of stroke.

OBJECTIVE

The objective of this review is to highlight an ocular sign that is seen in posterior circulation strokes called ocular lateral deviation (OLD). OLD is mostly seen in dorsolateral medullary strokes, and it is also seen in pontine and cerebellar strokes. OLD is detected by asking a patient to look straight ahead and then briefly close their eyes. Upon re-opening their eyes, the examiner will see that the eyes have deviated to one side; the patient's eyes will then make corrective saccade(s) to return to looking straight ahead. Complete eye deviation is a central sign of posterior circulation stroke.

DISCUSSION

OLD is an under-recognized vestibular ocular sign of central vestibulopathies including posterior circulation stroke. The most common location is in the dorsolateral medulla, where one-third of such strokes have complete OLD. Eye deviation can also be appreciated on computed tomography or magnetic resonance imaging. OLD can be detected up to 6 months after a posterior circulation stroke.

CONCLUSIONS

Checking for the sign of complete eye deviation in patients with dizziness/vertigo could be a simple, quick method for detecting posterior circulation stroke, and a means to improving the patients' outcome.

Posterior circulation stroke diagnosis in unselected group of acutely dizzy patients

BACKGROUNDS

Diagnostics of a posterior circulation ischemia (POCI) in patients with acute vertigo is a challenging task. Recently, the combination of HINTS (Head Impulse, Nystagmus and Test of Skew) exam and ABCD2 has been recommended to identify stroke in these patients. Until now, studies regarding HINTS have mostly been tested on preselected patient groups and their results are only partially applicable to real clinical practice.

AIMS

To compare the sensitivity and specificity of HINTS and ABCD2 and their combination in unselected acutely dizzy patients in the emergency department (ED) toward posterior circulation stroke detection.

METHODS

A prospective cross-sectional monocentric study in ED patients with acute onset of dizziness lasting less than 72 h. Their clinical characteristics, HINTS, vascular risk factors, ABCD2 scores and neuroimaging data were analyzed.

RESULTS

140 patients were recruited. Acute stroke was identified by MRI in 39 patients. All patients had central pattern nystagmus, skew deviation or further focal neurological finding. The age (≥60) and arterial hypertension clearly distinguished stroke and non-stroke group (p < 0001). The sensitivity of HINTS, ABCD2 and their combination in the unselected group was high (82,1 - 97,4%), but specificity low. After removing patients with inconclusive diagnosis, including transitory ischemic attack, specificity was much higher and comparable to previously published results.

CONCLUSIONS

The sensitivity and specificity of HINTS in previously published studies may vary because of their selection criteria. Even though, our study was performed on the unselected patient cohort, combination of HINTS and ABCD2 remained highly sensitive in detecting POCI and outperformed each of these tests alone.

Isolated axial lateropulsion caused by an acute lateral medullary infarction involving the dorsal spinocerebellar tract: A case report

Lateral medullary syndrome encompasses a broad spectrum of symptoms and signs depending on the bulbar localization of the lesion. Body lateropulsion (BL) can occur without vestibular and cerebellar symptoms, as a unique manifestation of a lateral medullary infarction. However, it is relatively rare and challenging to diagnose. We report a case of a 72-year-old woman who presented with a tendency to fall to the right. She denied having vertigo, cerebellar signs, sensory loss, or motor weakness. No signs of vestibular dysfunction were found on the ENT examination. Neurological evaluation was unremarkable, except for mild ataxia of the right limbs along with BL to the right side when standing and walking. Brain magnetic resonance (MR) imaging showed an acute small infarct in the right lateral aspect of the medulla extending from the rostral to the caudal level. MR angiography found no stenosis or vascular occlusions. We believe that ipsilateral axial lateropulsion shown by our patient may be related to a selective ischemic lesion of the dorsal spinocerebellar tract in its medullary course. A lateral medullary infarction should be seriously considered in patients who present with isolated BL without further signs of bulbar involvement.