Isolated ischemic third-nerve palsy as a warning sign of severe internal carotid artery stenosis

Partial oculomotor nerve palsy in a 7-year-old child

Oculomotor nerve palsy can be due to varied causes that include diabetic neuropathy, myasthenia gravis, brainstem infarction, demyelinating conditions, and cerebral aneurysms. Among the aneurysmal causes of oculomotor nerve palsy, aneurysm of the posterior communicating artery has been observed to be the most common. Pupillary dysfunction is considered to be an important feature of aneurysmal oculomotor nerve paresis. A case of a 7-year-old boy with partial oculomotor nerve palsy with pupillary sparing is being reported here, the etiology of which is tortuous and ectatic distal internal carotid artery. This is a rare cause of oculomotor nerve paresis and to the best of our knowledge has not yet been reported in children. Ischemia rather than compression seems to be the most plausible cause in this case.

Isolated third, fourth, and sixth cranial nerve palsies from presumed microvascular versus other causes: a prospective study

PURPOSE

To estimate the proportion of patients presenting with isolated third, fourth, or sixth cranial nerve palsy of presumed microvascular origin versus other causes.

DESIGN

Prospective, multicenter, observational case series.

PARTICIPANTS

A total of 109 patients aged 50 years or older with acute isolated ocular motor nerve palsy.

TESTING

Magnetic resonance imaging (MRI) of the brain.

MAIN OUTCOME MEASURES

Causes of acute isolated ocular motor nerve palsy (presumed microvascular or other) as determined with early MRI and clinical assessment.

RESULTS

Among 109 patients enrolled in the study, 22 had cranial nerve III palsy, 25 had cranial nerve IV palsy, and 62 had cranial nerve VI palsy. A cause other than presumed microvascular ischemia was identified in 18 patients (16.5%; 95% confidence interval, 10.7-24.6). The presence of 1 or more vasculopathic risk factors (diabetes, hypertension, hypercholesterolemia, coronary artery disease, myocardial infarction, stroke, and smoking) was significantly associated with a presumed microvascular cause (P = 0.003, Fisher exact test). Vasculopathic risk factors were also present in 61% of patients (11/18) with other causes. In the group of patients who had vasculopathic risk factors only, with no other significant medical condition, 10% of patients (8/80) were found to have other causes, including midbrain infarction, neoplasms, inflammation, pituitary apoplexy, and giant cell arteritis (GCA). By excluding patients with third cranial nerve palsies and those with GCA, the incidence of other causes for isolated fourth and sixth cranial nerve palsies was 4.7% (3/64).

CONCLUSIONS

In our series of patients with acute isolated ocular motor nerve palsies, a substantial proportion of patients had other causes, including neoplasm, GCA, and brain stem infarction. Brain MRI and laboratory workup have a role in the initial evaluation of older patients with isolated acute ocular motor nerve palsies regardless of whether vascular risk factors are present.

Paralysies oculomotrices douloureuses : une approche diagnostique

We review the question of diagnosis of painful and relatively isolated ophthalmoplegia due to diseases affecting the ocular motor nerves. For each clinical setting, we provide an overview of the main causes and a practical way to approach the diagnosis. As vascular malformations should always be kept in mind in patients with painful ophthalmoplegia, emergency neuroradiological investigations may be needed. However, the etiological scope is wide and the rationale for choosing the more appropriate examination and its optimal timing depends exclusively on the clinical evaluation. Despite advances in investigation techniques, diagnosis may remain difficult or even unresolved in a certain number of patients. We discuss successively paralysis of the third, sixth and fourth nerve, paralysis of several ocular motor nerves, recurrent ophthalmoplegia and ischaemic ocular motor palsies, which are the most frequent cause.

Upper cranial nerve palsy resulting from spontaneous carotid dissection

INTRODUCTION

Upper cranial nerve palsy has a variety of causes such as cerebral and nerve ischemia, diabetes, infectious and non-infectious meningitis, subarachnoid hemorrhage and intracranial aneurysm. CASE 1 : A 45-year-old man suffered from holocephalic headaches and a right-sided neck pain for two weeks. He presented to our emergency department because of a sudden ptosis of the right eye. On admission neurological examination revealed a right sided Horner's syndrome and hypesthesia of the right side of the face. Magnetic resonance angiography identified a circumscribed dissection of the right extracranial internal carotid artery originating from the carotid bifurcation. Conventional angiography 2 weeks later showed a nearly recanalized artery. CASE 2 : A 55-year-old previously healthy man without cardiovascular risk factors developed right sided neck pain when loading a seeder with several sacks of crop. A few hours later he noticed a left-sided weakness. On admission a severe left sided hemiparesis and a mild neglect were present. Duplex sonography revealed a right-sided distal internal carotid artery (ICA) occlusion. The next morning the patient complained of double vision; he had a right-sided pupil-sparing oculomotor palsy. The diagnosis of ICA dissection was confirmed by conventional angiography, at that time showing a partially recanalized ICA without involvement of the cavernous region by the dissection.

CONCLUSION

ICA dissection must be included in the differential diagnosis of upper cranial nerve palsy and should be assessed by duplex ultrasound and magnetic resonance imaging. A possible explanation is nerve ischemia due to a transient or permanent interruption of the blood supply by compression of the vasa nervorum originating from the intracranial carotid artery.

Acute ocular motor mononeuropathies: prospective study of the roles of neuroimaging and clinical assessment

The role for immediate neuroimaging in patients 50 years of age or older with acute isolated third, fourth, and sixth nerve palsies is controversial. We prospectively evaluated 66 patients, aged 50 years and older (median 67 years, range 50-85), with acute isolated ocular motor mononeuropathies. Our purpose was to evaluate both the role of neuroimaging and the role of clinical assessment in determining etiology. We found that clinical features, including time to maximal diplopic symptoms, were not predictive of etiology (median 2 days to maximal diplopic symptoms for both peripheral microvascular and other etiologies). The presence of any common vascular risk factor, including diabetes mellitus, hypertension, hypercholesterolemia, or coronary artery disease, was significantly associated with peripheral microvascular etiology in this cohort (p=0.0004, Fisher's exact test). Despite the high prevalence of peripheral microvascular ischemia as an etiology in this age group, other causes were identified by magnetic resonance imaging (MRI) or computed tomography (CT) scanning in 14% of patients. Diagnoses included brainstem and skull base neoplasms, brainstem infarcts, aneurysms, demyelinating disease, and pituitary apoplexy. Neuroimaging procedures may have a role in the initial evaluation of patients 50 years of age or older with acute ocular motor mononeuropathies.