Bilateral ophthalmoplegia: an unusual sign of the top of the basilar artery syndrome

Occlusion type and posterior communicating artery patency may predict favorable outcome after endovascular thrombectomy in selective basilar top occlusion

Introduction

The top of the basilar artery is a five-branched junction, consisting of two superior cerebellar arteries (SCAs), two posterior cerebellar arteries (PCAs), and the basilar artery itself. This study aimed to investigate prognostic factors in patients with selective acute basilar top occlusion managed with mechanical thrombectomy, focusing on occlusion type and posterior communicating artery (PCoA) patency.

Methods

Eligible patients who underwent endovascular treatment (EVT) for acute basilar top occlusion were reviewed. Patterns of basilar top occlusion were categorized as types I–III according to whether the SCA and PCA were visible on angiography. The PCoA was categorized as hypoplastic or non-visible (type I), normal patency but non-visible PCA through PCoA flow (type II), and fetal type (type III).

Results

Good outcomes were observed in 50% (21/42) and mortality in 11.9% (5/42) of the cases at 90 days. Patients with good outcomes showed lower baseline National Institutes of Health Stroke Scale (NIHSS) score (P = 0.001) and a higher proportion of type III basilar top occlusion (P = 0.004) and type III PCoA (P = 0.001). Multivariable logistic analysis showed that baseline NIHSS score [odds ratio (OR), 0.84; 95% confidence interval (CI), 0.73–0.97; P = 0.017) and type III PCoA (OR, 21.54, 95% CI, 1.33–347.97; P = 0.031) were independent predictors of good functional outcomes.

Conclusion

A low initial NIHSS score and good PCoA patency were independent predictors of favorable clinical outcomes after EVT in patients with acute basilar top occlusion. Furthermore, the favorable outcome group showed a high proportion of type III basilar top occlusions.

Reverse Locked-In Syndrome

BACKGROUND

Basilar artery occlusion can cause locked-in syndrome, which is characterized by quadriplegia, anarthria, and limited communication via eye movements. Here, we describe an uncommon stroke syndrome associated with endovascular recanalization of the top of the basilar artery: "reverse locked-in syndrome."

METHODS

We report the case of a patient with atypical neurological deficits caused by acute ischemic stroke of the midbrain tegmentum. We perform neuroanatomic localization of the patient's infarcts by mapping the magnetic resonance imaging (MRI) data onto a brainstem atlas.

RESULTS

A 61-year-old man presented with acute coma and quadriplegia due to top of the basilar artery occlusion. He underwent emergent endovascular thrombectomy, with successful recanalization of the basilar artery at 4 h and 43 min post-ictus. The patient regained consciousness and purposeful movement in all four extremities, but the post-procedure neurological examination demonstrated bilateral ptosis with complete pupillary and oculomotor paralysis. MRI revealed infarction of the bilateral oculomotor nuclei in the midbrain tegmentum. At 9-month follow-up, he had anisocoria and dysconjugate gaze, but was living at home and required minimal assistance in performing all activities of daily living.

CONCLUSIONS

Since the patient's deficits were the exact opposite of those described in locked-in syndrome, we propose the term "reverse locked-in syndrome" to describe this neurological entity characterized by bilateral ptosis, non-reactive pupils, and ophthalmoplegia with preservation of consciousness and extremity motor function.

Clinically Directed Neuroimaging of Ophthalmoplegia

PURPOSE

Ophthalmoplegia (OP) can have numerous etiologies and different clinical presentations. Most causes of OP can be narrowed down to specific anatomical locations based on clinical information. The aim of this study was to outline the different categories of diseases encountered in patients with OP, based on the location along the ocular motor pathways, and the most appropriate imaging modality for the given scenarios.

METHODS

Representative neuroimaging examples of pathological processes causing OP are displayed, sequenced by anatomical location and disease category. Correlations between the clinical presentation and site of pathology with imaging protocol recommendations are also presented.

RESULTS

Diseases affecting ocular movement can be divided into categories including: injuries or diseases of the cerebral hemispheres, midbrain, pons, and cerebellum, ocular motor nerve palsies, intrinsic extraocular muscle diseases and orbital diseases secondarily affecting the extraocular muscles. The cranial nerves responsible for ocular movements can be affected intrinsically or extrinsically along their nuclei, their course in the brainstem, in the cisterns, skull base, cavernous sinuses and orbits. The extraocular muscles can be affected primarily or secondarily by adjacent pathological processes in the orbit. Clinical information can help narrow down the differential diagnoses in terms of anatomical site of involvement and prompt the most appropriate neuroimaging techniques.

CONCLUSION

By understanding the pathophysiology of OP the neuroradiologist can discuss clinical cases with the referring clinician and determine a timely, accurate method of imaging to achieve the most precise differential diagnosis.

Bilateral internuclear and internal ophthalmoplegia due to artery of Percheron infarction

The artery of Percheron (AOP) infarction always manifests as paramedian bilateral thalamic infarcts and might present as paramedian midbrain infarcts. Despite the limited MRA evaluation, due to small size of the artery, careful evaluation of the patient's history, the clinical presentation with imaging findings can facilitate the proper diagnosis.

Complete bilateral ophthalmoplegia resistant to caloric stimulation in bilateral paramedian midbrain-thalamic infarction

A 79-year-old woman who developed bilateral paramedian midbrain-thalamic infarction manifested complete bilateral ophthalmoplegia resistant to caloric stimulation, indicating impairment of the vestibulo-ocular reflex (VOR). Previous reports have mentioned this phenomenon but have not explicitly reported the results of caloric testing. Why a lesion apparently confined to the upper brainstem should produce impairment of the horizontal VOR remains unexplained.

Complete Ophthalmoplegia

Background and Purpose— Complete ophthalmoplegia, the combination of bilateral ptosis with loss of all extraocular movements, is rarely a consequence of ischemic stroke. We describe 3 patients who had complete ophthalmoplegia as a manifestation of bilateral paramedian midbrain-thalamic infarction, and we discuss possible pathophysiologic mechanisms.

Summary of Cases— Three patients presented with coma. All had complete ophthalmoplegia that initially persisted despite improvement or fluctuation in their other deficits. MRI revealed bilateral paramedian midbrain-thalamic infarction. Two patients died, with the ophthalmoplegia remaining unchanged before death. The surviving patient had a progressive improvement in ocular abduction but persisting third nerve and vertical gaze palsies.

Conclusions— Complete ophthalmoplegia is an unusual sign of bilateral paramedian midbrain-thalamic infarction. The ophthalmoplegia could result from combined third nerve, pseudoabducens, and vertical gaze palsies.