Thirteen-And-A-Half Syndrome

One-and-a-Half Syndrome in a Case of Brainstem Bleed

One-and-a-half syndrome (OHS) is a horizontal gaze palsy in one direction with internuclear ophthalmoplegia (INO) in the other. The only eye movement possible is the abduction of the contralateral eye with nystagmus. The usual structures affected are the medial longitudinal fasciculus and paramedian pontine reticular formation or the abducens nucleus. Most commonly, the OHS is caused by ischemia and demyelinating lesions. The other causes include infectious, neoplastic, and rarely traumatic. We report a case of a 42-year-old non-compliant hypertensive female who presented with giddiness, projectile vomiting, and right-sided hemiparesis and was found to have OHS on cranial nerve examination in the emergency department (ED). In the ED, the presence of complete horizontal gaze palsy in one direction with INO in the other direction should raise suspicion of a brainstem pathology.

A Rare Neuro-Ophthalmological Condition in a Patient with Lung Adenocarcinoma: The Eight-and-a-Half Syndrome, Case Report and Review of the Literature

The eight-and-a-half syndrome is a rare neuro-ophthalmological condition caused by a structural lesion in the dorsal portion of the pons, involving critical areas of the brainstem, i.e., medial longitudinal fasciculus (MLF), abducens nucleus, facial genu, and colliculus. It is characterized by internuclear ophthalmoplegia with horizontal gaze palsy and peripheral facial palsy. Although the syndrome is most frequently caused by vascular or demyelinating diseases, several different underlying causes might occur. Herein, we describe a case of the eight-and-a-half syndrome caused by a lung adenocarcinoma metastasis localized in the lower pontine tegmentum. Then, we review the current literature on the underlying causes of the eight-and-a-half syndrome.

Ocular Motor Dysfunction Due to Brainstem Disorders

BACKGROUND

The brainstem contains numerous structures including afferent and efferent fibers that are involved in generation and control of eye movements.

EVIDENCE ACQUISITION

These structures give rise to distinct patterns of abnormal eye movements when damaged. Defining these ocular motor abnormalities allows a topographic diagnosis of a lesion within the brainstem.

RESULTS

Although diverse patterns of impaired eye movements may be observed in lesions of the brainstem, medullary lesions primarily cause various patterns of nystagmus and impaired vestibular eye movements without obvious ophthalmoplegia. By contrast, pontine ophthalmoplegia is characterized by abnormal eye movements in the horizontal plane, while midbrain lesions typically show vertical ophthalmoplegia in addition to pupillary and eyelid abnormalities.

CONCLUSIONS

Recognition of the patterns and characteristics of abnormal eye movements observed in brainstem lesions is important in understanding the roles of each neural structure and circuit in ocular motor control as well as in localizing the offending lesion.

Atypical "nine" syndrome in bilateral pontine infarction: A case report

RATIONALE

"Nine" syndrome, that is "eight-and-a-half" syndrome associated with hemiplegia and hemidysesthesia, is a rare disorder. This study aimed to report a Chinese patient with acute bilateral pontine infarction manifesting as eight-and-a-half syndrome plus hemiplegia (atypical nine syndrome), and also the clinical and neuroimaging findings were explained and discussed with review of the literature.

PATIENT CONCERNS

A 79-year-old woman experienced sudden vertigo, nausea, vomiting, and weakness at her left arm and leg. The neurological examination disclosed her right horizontal gaze palsy, internuclear ophtalmoplegia (INO), and right-sided peripheral facial paralysis combined with slight left-sided hemiplegia, which were consistent with atypical nine syndrome.

DIAGNOSES

Cranial magnetic resonance imaging (MRI) displayed acute multiple ischemic infarction, involving bilateral pontine tegmentum, basilar part of right paramedian pontine, and left cerebellar hemisphere. Intracranial MR angiography (MRA) revealed right middle cerebral artery occlusion, no clear visualization of bilateral vertebral arteries, and basilar artery hypoplasia with stenotic segments.

INTERVENTIONS

Thrombolysis could not be performed due to the time window. The patient was given low molecular weight heparin for anticoagulation because of posterior circulation and progressive stroke.

OUTCOMES

The vertigo disappeared, and a notable improvement with minimal restriction in the right horizontal gaze and partial relief of her facial paralysis were found at discharge, while her left hemiparesis was fully resolved. No recurrence of cerebral infarction was observed during follow-up as well.

LESSONS

This case report with atypical nine syndrome is fairly rare. Nine syndrome may refer to the lesion located in unilateral tegmentum of the caudal pontine plus paramedian pontine, with an important localization value.

Eight Syndrome: Horizontal Gaze Palsy Plus Ipsilateral Seventh Nerve Palsy

A 62-year-old woman developed a right horizontal gaze palsy and ipsilateral facial nerve palsy due to a right pontine tegmentum infarct. This constitutes a forme fruste of the eight-and-a-half syndrome that we have termed the eight syndrome.

Eight-and-a-half syndrome caused by a pontine haemorrhage: a case report and review of the literature

BACKGROUND

Eight-and-a-half syndrome is caused by a lesion in the dorsal tegmentum of the caudal pons involving parapontine reticular formation and median longitudinal fasciculus, as well as the nucleus and/or the fasciculus of the facial nerve. It is characterized by one-and-a-half syndrome and an ipsilateral cranial nerve VII palsy. Also, many variants of eight-and-a-half syndrome have been described, including nine syndrome, thirteen-and-a-half syndrome and fifteen-and-a-half syndrome.

METHODS

We describe a case of a 49-year-old man who presented with eight-and-a-half syndrome combined with contralateral hemiparesis. We reviewed the literature describing the related spectrum of eight-and-a-half syndrome associated with various etiologies.

RESULTS

Brain computed tomography scan revealed a hyperdensity located in the left paramedian aspect of the dorsal pons. T2-weighted magnetic resonance imaging at the 11-month follow-up showed hyperintensity and enlargement of the inferior olivary nuclei, which were compatible with a diagnosis of hypertrophic olivary degeneration. In light of our observations and cases reported in the literature, we categorize the spectrum of eight-and-a-half syndrome into three types, namely classic eight-and-a-half syndrome, eight-and-a-half syndrome variants and eight-and-a-half plus syndrome. Besides, the clinical feature and outcome of the three types are discussed in this article.

CONCLUSIONS

Recognition of the spectrum of eight-and-a-half syndrome allows precise anatomic localization of the lesion to pontine tegmentum region.

One-and-a-half syndrome with its spectrum disorders

One-and-a-half syndrome is a syndrome characterized by horizontal movement disorders of the eyeballs, which was first reported and named by Fisher in 1967. It presents a combination of ipsilateral conjugate horizontal gaze palsy (one) and ipsilateral internuclear ophthalmoplegia (INO) (a half). On the basis of the one-and-a-half syndrome, there are a series of related rare syndromes called the one-and-a-half syndrome spectrum disorders. This article reviews rare cases of one-and-a-half syndrome spectrum disorder, describes the clinical and pathological features of different syndromes, and summarizes their nomenclature.