Ocular motor disturbances occurring as false localizing signs in ruptured intracranial aneurysms

A Case of a Ruptured Microaneurysm at the Tip of the Basilar Artery With Right Abducens Nerve Palsy at the Time of the Initial Rupture and Rerupture During an Outpatient Follow-Up

The presentation of abducens nerve palsy after each occurrence of subarachnoid hemorrhage (SAH) is rare. Herein, we report the case of a patient with a ruptured microaneurysm at the tip of the basilar artery who presented with right abducens nerve palsy at the time of the initial rupture and rerupture during an outpatient follow-up. A 52-year-old woman developed SAH with right abducens nerve palsy, which was treated with coil embolization. One year after the initial SAH, there was a relapse of the SAH and paresis of the right abducent nerve palsy. This may have been caused by the location of the abducens nerve in relation to the surrounding structures, which were susceptible to the effects of hematoma or intracranial pressure fluctuations. Stent-assisted coil embolization is an effective treatment for regrowth that appears after endovascular therapy of microaneurysms.

Clinical Course of Abducens Nerve Palsy in Patients with Ruptured Vertebral Artery Dissecting Aneurysms

Objective

There are few detailed reports on abducens nerve palsy due to a ruptured vertebral artery dissecting aneurysm (VADA). We investigated the clinical characteristics and long-term course of abducens nerve palsy in ruptured VADA patients treated by endovascular surgery.

Methods

Of the 51 cases of ruptured VADA treated by endovascular intervention from 2011 to 2019, 31 with a good/fair outcome, in which ocular motility disorder was able to be followed, were included and investigated.

Results

In all, 11 patients (35.5%) had abducens nerve palsy, and the World Federation of Neurological Surgeons (WFNS) grade and Hunt & Hess (H&H) grade at the time of arrival of patients with abducens nerve palsy were significantly higher than those of patients without abducens nerve palsy. Of the 10 patients who were able to be followed, abducens nerve palsy in 3 completely recovered in 7-180 days. Abducens nerve palsy improved in five patients and remained in two patients.

Conclusion

More severe neurological findings on admission reflect a higher rate of abducens nerve palsy. Diplopia induced by abducens nerve palsy is one of the most important sequelae of ruptured VADA, which impairs the daily activities of the patients. Some cases of abducens nerve palsy improve over a long period. Therefore, appropriate diagnosis and follow-up should be concerned.

Recovery of oculomotor nerve palsy after endovascular management of posterior communicating artery aneurysms

BACKGROUND

Oculomotor nerve palsy (ONP) is a common clinical presentation of posterior communicating artery (PcomA) aneurysms. It remains unclear if patients have a better rate of recovery after surgical clipping or endovascular coiling.

OBJECTIVES

The main objectives of this study were to assess the overall rate of ONP recovery after endovascular coiling of PcomA aneurysms, as well as to determine the associated predictive factors of oculomotor nerve recovery.

METHOD

We retrospectively evaluated the demographic, clinical, and radiological characteristics and the outcome of consecutive patients presenting with PcomA aneurysms treated by endovascular coiling from January 2012 to November 2016 with at least 1 year clinical and radiological follow-up. Statistical analysis was applied to determine the association between ONP recovery and the demographic, clinical and radiological variables.

RESULTS

A total of 91 patients with PcomA aneurysms were treated endovascularly. Thirty-four patients (22 women and 12 men) with ONP related to PcomA aneurysms were included. The mean age of the patients was 49.8 years. Subarachnoid haemorrhage was present in 27 patients. The mean aneurysm size was 6.7 mm. The overall rate of recovery was 88.2%. Complete nerve recovery was seen in 16 (47%) patients and partial recovery was observed in 14 (41.2%) patients, whilst 4 (11.8%) patients remained unchanged after treatment. The non-posterolateral direction of the aneurysm showed a tendency towards better recovery compared to the posterolateral projection (p = 0.06).

CONCLUSION

Endovascular coiling of PcomA aneurysms in patients with ONP resulted in a cure or improvement of oculomotor nerve dysfunction in the majority of patients.

Transient Complete Unilateral Oculomotor Nerve Palsy following Clipping of Ruptured Anterior Communicating Artery Aneurysm: An Abstruse Phenomenon

Background

Aneurysmal subarachnoid hemorrhage may be associated with different cranial nerve palsies, with oculomotor nerve palsy (ONP) being the most common. ONP is especially associated with posterior communicating artery aneurysms, due to the anatomical proximity of the nerve to the aneurysmal wall. Anterior communicating artery (Acom) aneurysms are very unlikely to produce ONP due to the widely separated anatomical locations of Acom and oculomotor nerve.

Case Description

Here we describe the case of a 60-year-old nondiabetic lady who presented with Acom aneurysmal subarachnoid hemorrhage having a World Federation of Neurosurgical Societies (WFNS) grade I. She underwent an uneventful right pterional craniotomy and clipping of the aneurysm, except for a short period of controlled rupture of the aneurysm. Postoperatively she developed complete ONP on the right side, though her sensorium was preserved. Computed Tomogram and Magnetic Resonance Imaging scans of the brain did not yield any useful information regarding its etiology. She was conservatively managed and kept on regular follow-up. She had a gradual recovery of ONP in the following order: pupillary reaction, ocular movements, and finally ptosis. On postoperative day 61, she had complete recovery from ONP.

Conclusion

We describe a very unusual case of complete ONP following Acom aneurysm clipping and its management by masterly inactivity.

Isolated trochlear nerve palsy with perimesencephalic subarachnoid haemorrhage

Perimesencephalic subarachnoid haemorrhage is usually asymptomatic other than meningeal irritation sign. The authors report a case of subarachnoid haemorrhage at the quadrigeminal cistern showing ipsilateral trochlear nerve palsy and discuss the pathogenesis. A 71-year-old man with a history of diabetes mellitus and acute myocardial infarction presented with diplopia. He underwent CT, which revealed subarachnoid haemorrhage at the left quadrigeminal cistern. Neurological examination revealed left isolated trochlear nerve palsy, with results otherwise normal. The diagnosis of perimesencephalic subarachnoid haemorrhage was established on neuroimaging. The amount of haemorrhage is related to symptoms. A dense clot in the quadrigeminal cistern might have been the cause of trochlear nerve palsy.

Ophthalmic segment aneurysmal subarachnoid hemorrhage presenting with contralateral abducens nerve palsy: a false localizing sign

BACKGROUND

Neuro-ophthalmic manifestations of aneurysmal subarachnoid hemorrhage are commonly linked to a palsy of the cranial nerve in close proximity to the aneurysm or to chronic intracranial hypertension.

CASE REPORT

A patient with subarachnoid hemorrhage secondary to a rupture of an intracranial right ophthalmic segment internal carotid artery aneurysm presented with an acute-onset contralateral abducens nerve palsy. There were no clinical or radiologic features of chronic intracranial hypertension. Magnetic resonance imaging showed a co-existent ectatic basilar artery on the left side of the pons in close relation to the sixth nerve.

CONCLUSION

Abducens weakness in the above-50 age group is most commonly caused by a vascular etiology. The authors discuss the pathogenesis of this rare clinical entity and present pertinent literature review.

False localizing signs in traumatic brain injury

BACKGROUND

Hemiparesis ipsilateral to a mass-occupying lesion can be due to Kernohan-Woltman Notch Phenomenon (KWNP). This syndrome implies a false-localizing sign because clinical findings lead the examiner to an incorrect neuroanatomical diagnosis. The contralateral crus cerebri (pyramidal tract) is pressed against the tentorial incisum and a resultant hemiparesis is found on the same side of the lesion.

REVIEW

A detailed literature search of false-localizing signs is presented.

CONCLUSIONS

Not infrequently, patients presenting to a physiatrist may have incomplete records. The existence of false localizing signs may point the physician towards the wrong underlying pathology.

Ruptured anterior communicating artery aneurysm causing bilateral oculomotor nerve palsy: a case report

A rare case of bilateral third cranial nerve palsy due to a ruptured anterior communicating artery aneurysm is presented. A 68-yr-old woman was semicomatose with bilaterally fixed dilated pupil, abducted eyes, and ptosis. A computed tomography demonstrated extensive hemorrhage spreading around the both Sylvian and interhemisheric fissure without focal mass effect. Intracranial pressure via extraventricular drainage before surgery was 15-50 mmHg. Three months later, brain MRI showed infarction of left posterior cerebral artery territory and lacuna infarction of the pons. Eleven months after aneurysm repair, nerve palsy improved slowly and recovered partially. The patient communicated well with simple words. The author reviewed and discussed the possible mechanism of this rare neuro-ophthalmological manifestation in view of a false localizing sign.

The evaluation of isolated third nerve palsy revisited: an update on the evolving role of magnetic resonance, computed tomography, and catheter angiography

The evaluation and management of the neurologically isolated third nerve palsy continues to evolve. The major concern for the clinician confronted with a patient with a third nerve palsy has been the exclusion of an intracranial aneurysm. The evolution of new imaging techniques, such as computed tomography angiography and magnetic resonance angiography, have provided new imaging options for clinicians. This article reviews the pertinent recent literature on the use of these imaging studies in evaluating the patient with a third nerve palsy.

Early surgery improves the cure of aneurysm-induced oculomotor palsy

BACKGROUND

Aneurysm of the internal carotid-posterior communicating artery (ICA-PCoA) is the most frequent cause of sudden unilateral oculomotor palsy. Timely surgery for the aneurysm is the most important factor for third nerve recovery.

METHODS

We scrutinized the world literature with nearly one thousand cases of isolated unilateral oculomotor palsy caused by intracranial aneurysms and treated with surgery. Only those reports (one-third of all) in which the time interval between onset of oculomotor palsy and surgery could be determined were included. We treated 1314 patients with cerebral aneurysms (183 = 14% with ICA-PCoA aneurysms) from our catchment area in Eastern Finland during years 1977-1992. Twenty-eight patients having oculomotor palsy caused by ICA-PCoA aneurysm had surgery as soon as the diagnosis was made.

RESULTS

Eight of 9 patients operated within three days (0-3) and 4 of 6 patients operated on within 4 to 6 days the onset of oculomotor palsy had complete recovery of their third nerve function, in contrast to only 4 of 13 patients operated on later. Especially those operated on more than four weeks later had a dismal outcome: only 1 of 6 had complete recovery.

CONCLUSIONS

We recommend immediate admission and acute or early surgery for aneurysm-induced third nerve palsy, preferably within 3 days, to avoid functionally and cosmetically invalidizing disability.

Bilateral third cranial nerve palsies in association with a ruptured anterior communicating artery aneurysm

Third cranial nerve palsy occurring in a patient with an intracranial aneurysm is typically unilateral and associated with an internal carotid-posterior communicating or distal basilar artery aneurysm. In this report a patient with bilateral third cranial nerve palsies associated with rupture of an anterior communicating artery aneurysm is described. Raised intracranial pressure without brain herniation and compression of the third nerves within the perimesencephalic cisterns by focal subarachnoid clot are suggested as possible underlying mechanisms of the palsies, which showed complete recovery at 4 months after the hemorrhage and subsequent early aneurysm repair.

Reversal of oculomotor disorders after intracranial aneurysm surgery

Forty-nine patients with oculomotor nerve palsy due to intracranial aneurysm were examined. The reversal of third nerve palsy is related to modality of onset and surgical timing: "early" surgery (within 14 days from the onset of oculomotor palsy) promises a better prognosis for ocular function; recovery starting within the first month will probably be complete. A full recovery is probably seen only with conduction block (neuroapraxia) or minor axonal changes (axonolysis). Clinical features of third nerve palsy due to intracranial aneurysms versus other causes of oculomotor palsy are discussed.