"Nine" syndrome: A new neuro-ophthalmologic syndrome: Report of two cases

An unusual presentation of hemiparesis with complex ophthalmoplegia: A ‘nine’ syndrome

Nine syndrome is a rare clinical entity with core clinical signs of one and a half syndrome, ipsilateral facial palsy, and contralateral hemiparesis/hemianesthesia and localizing to the dorsal paramedian pontine tegmentum. The awareness of this sign helps in precise localization and consideration of relevant aetiologies. Here, we report a case consisting of right horizontal gaze palsy with right internuclear opthalmoplegia and right lower motor neuron type VII nerve palsy constituting eight-and-a-half syndrome. With the additional involvement of left upper and lower limb upper motor neuron weakness, it revealed the lesion responsible for the ‘nine’ syndrome in magnetic resonance imaging of the brain. It is our purpose to highlight the genesis of this combination of clinical signs.

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.

Nine Syndrome: Case Report and Review of Clinical Signs in Internuclear Ophthalmoplegia

The pathologic involvement of brainstem and midbrain nuclei and white matter tracts in various combinations may result in a spectrum of arithmetically derived syndromes. They include ‘one and a half syndrome’, ‘eight and a half syndrome’ and ‘fifteen and a half syndrome’. We report a case of ‘nine syndrome’, which has been reported more recently, caused by caused by acute pontine infarcts and characterised clinically by a combination of internuclear ophthalmolplegia, ipsilateral horizontal gaze palsy, lower motor neuron type of facial palsy, contralateral hemiparesis and hemianesthesia. We highlight the genesis of this combination of clinical signs, revisit the different variants of INO and review the literature on ‘Nine syndrome’.

"Eight and a half" and "nine syndrome" rare presentation of pontine lesions; case reports and review of literature

Background: Eight-and-a-half syndrome (EHS) is one-and-a-half syndrome [(conjugated horizontal gaze palsy and internuclear ophthalmoplegia (INO)] plus ipsilateral fascicular seventh cranial nerve palsy. Involvement of lower pontine tegmentum including the abducens nucleus, the ipsilateral medial longitudinal fasciculus (MLF), and the adjacent facial colliculus contribute to the clinical findings of EHS. Recently, nine syndrome with addition of hemiparesis or hemianesthesia to EHS (due to involvement of adjacent corticospinal tract or medial lemniscus) is suggested. Methods: Consecutive patients with presentation of EHS or nine syndrome were reviewed from referral neuro-ophthalmology and strabismus clinics. Results: Three cases of EHS were identified with different etiologies of intracerebral hemorrhage (ICH), demyelination, and neuromyelitis optica spectrum disorder. Moreover, one case of "nine syndrome" due to ICH was described. Brain magnetic resonance imaging (MRI) in all of them revealed lesion in lower tegmentum of pons. Conclusion: Apart from different etiologies, recognition of EHS or nine syndrome allows precise localization of the lesion to lower pontine tegmentum ipsilaterally.

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.