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

A Rare Presentation of Posterior Circulation Strokes: A Case Report of Nine Syndrome

Nine syndrome is a rare variant of one-and-a-half syndrome that results from a stroke in the posterior circulation, mainly manifesting as ipsilateral horizontal gaze palsy, facial palsy, and contralateral hemiataxia. Awareness of the clinical signs of this syndrome is crucial for accurate localization of the lesion and guiding further investigations. We report a case of nine syndrome presenting with signs of one-and-a-half syndrome, ipsilateral facial nerve palsy, hemiataxia, and hemiparesis. There are only a few cases of nine syndrome reported in the literature.

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.

Eight-and-a-half syndrome as manifestation of acute disseminated adenovirus encephalomyelitis

Acute disseminated encephalomyelitis is an immune mediated inflammatory-demyelinizing disease that usually manifests after infection or vaccination in school-age children. It typically presents a prodromal phase with flu-like symptoms, followed by a phase with varied clinical symptoms, neuro-ophthalmological alterations such as ophthalmoplegia or optic neuritis may occur. The differential diagnosis includes tumor, vascular, infectious, inflammatory and demyelinating diseases. Diagnosis is based on the clinical history and the characteristics of brain magnetic resonance imaging, the gold standard test. The study of the cerebrospinal fluid can help to guide the clinical picture. The prognosis is favorable, with an excellent response to corticosteroids and immunoglobulins, with minimal long-term sequelae in most cases. We report the case of an 8-year-old male with acute demyelinating disease due to adenovirus whose manifestation was an eight-and-a-half syndrome.

Sixteen syndrome: a rare presentation of central demyelination

This case illustrates two diagnostic challenges for clinicians: the rarely described sixteen syndrome and the relationship between tumour necrosis factor (TNF)-alpha inhibitors and central demyelination. Sixteen syndrome affects horizontal eye movements and the facial nerve bilaterally reflecting a lesion in the posterior pontine tegmentum, adjacent to the fourth ventricle. Given its rarity and complexity of clinical signs, this syndrome risks misdiagnosis and mismanagement. The relationship between TNF-alpha inhibitors and demyelination is a complex issue in which causality is yet to be established. This diagnostic challenge poses a management dilemma for clinicians.

How does a small area cause big syndromes? A case report of a patient with one-and-a-half syndrome and MRI review of the anatomical pathways involved in causing different pontine neuro-ophthalmological syndromes

Purpose

To describe the clinical symptoms, anatomical location of the injury and different etiologies of one-and-a-half syndrome and its variants.

Observations

A small lesion to the brainstem can cause complex syndromes that involve the disfunction of different nuclei and pathways. A 52-year-old man presented with sudden onset of diplopia characterized by horizontal gaze palsy and internuclear ophthalmoplegia (INO). With these clinical characteristics, the patient was diagnosed with the one-and-a-half syndrome. Neuroimaging revealed an acute/subacute ischemic lacunar event in the pontine tegmentum. The one-and-a-half syndrome is described as a horizontal gaze palsy in one direction (damage to the paramedian pontine reticular formation [PPRF] or the VI nerve nucleus) and an internuclear ophthalmoplegia in the other direction (damage to the medial longitudinal fasciculus). Along with the traditional description, the closed anatomical proximity with other nuclei and pathways makes possible the appearance of other more complex syndromes that have been grouped as the one-and-a-half syndrome and its variants.

Conclusions and importance

A detailed clinical neuro-ophthalmologic examination, along with a clear understanding of the neuroanatomical pathways, gives clinicians a good diagnostic opportunity to determine the precise location of injuries to the brainstem.

One-and-a-half Syndrome Associated with Multiple Sclerosis in a 14-year-old Girl

Purpose: To report the case of a 14-year-old female patient with one-and-a-half syndrome subsequently diagnosed with multiple sclerosis involving the pons.Case summary: A 14-year-old girl without any underlying disease presented with difficulty focusing and mild headache for 5 days. The patient showed conjugate gaze palsy to the left, limited adduction in the left eye, and abducting nystagmus in the right eye, which indicated one-and-half syndrome. T2 fluid-attenuated inversion recovery brain magnetic resonance imaging revealed multiple punctate hyperintensities in the pontine tegmentum, bilateral cerebral white matter, and cerebellum. Cerebrospinal fluid examination revealed oligoclonal bands and multiple sclerosis was diagnosed. The patient was treated with intravenous steroids and beta-interferon. Seven weeks later, limitation of eyeball movement and nystagmus had resolved completely.Conclusions: At the young age of 14 years, a patient presenting with one-and-a-half syndrome was diagnosed with multiple sclerosis. Children with multiple sclerosis may experience severe physical and cognitive impairments, and brainstem involvement predicts an especially poor prognosis. Early diagnosis and active treatment may help to prevent poor outcomes.

Chameleons, red herrings, and false localizing signs in neurocritical care

False localizing signs (FLS) and other misleading neurological signs have long been an intractable aspect of neurocritical care. Because they suggest an incorrect location or etiology of the pathological lesion, they have often led to misdiagnosis and mismanagement of the patient. Here, we reviewed the existing literature to provide an updated, comprehensive descriptive review of these difficult to diagnose signs in neurocritical care. For each sign presented, we discuss the non-false localizing presentation of symptoms, the common FLS or misleading presentation, etiology/pathogenesis of the sign, and diagnosis, as well as any other clinically relevant considerations. Within cranial neuropathies, we cover cranial nerves III, IV, V, VI, VII, VIII, as well as multiple cranial nerve involvement of IX, X, and XII. FLS ophthalmologic symptoms indicate diagnostically challenging neurological deficits, and here we discuss downbeat nystagmus, ping-pong-gaze, one-and-a-half syndrome, and wall-eyed bilateral nuclear ophthalmoplegia (WEBINO). Cranial herniation syndromes are integral to any discussion of FLS and here we cover Kernohan's notch phenomenon, pseudo-Dandy Walker malformation, and uncal herniation. FLS in the spinal cord have also been relatively well documented, but in addition to compressive lesions, we also discuss newer findings in radiculopathy and disc herniation. Finally, pulmonary syndromes may sometimes be overlooked in discussions of neurological signs but are critically important to recognize and manage in neurocritical care, and here we discuss Cheyne-Stokes respiration, cluster breathing, central neurogenic hyperventilation, ataxic breathing, Ondine's curse, and hypercapnia. Though some of these signs may be rare, the framework for diagnosing and treating them must continue to evolve with our growing understanding of their etiology and varied presentations.

'Twenty syndrome' in neuromyelitis optica spectrum disorder

A 30-year-old woman presented with recurrent hiccups, vomiting and painful diminution of vision and gait instability for 1 day. She had one-and-a-half syndrome, bilateral seventh cranial nerve paresis with bilateral symptomatic optic neuritis and left-sided ataxic haemiparesis. We described her disorder as the 'twenty syndrome' (1¹/₂+7+7+2+2+½=20). MRI of her brain revealed demyelination predominantly in right posterolateral aspect of pons, medulla and bilateral optic nerves. Serum antiaquaporin-4 antibody came out positive. Thus, she was diagnosed as neuromyelitis optica spectrum disorder (NMOSD). She responded brilliantly to immunosuppressive therapy. This is the first ever reported case of the 'twenty syndrome' secondary to cerebral NMOSD.

A Case Report of Wall-Eyed Bilateral Internuclear Ophthalmoplegia with Bilateral Facial Palsy

Case reports of bilateral facial palsy with horizontal gaze restriction are rare. A 62-year-old woman experienced sudden onset of bilateral adduction deficits, bilateral abducting nystagmus accompanied with facial diplegia. We confirmed acute ischemic stroke in the midline dorsal pons, where medial longitudinal fasciculus (MLF) and facial nerve fascicles are located. This can be explained by vascular variation of pontine perforating arteries.

WEBINO syndrome (wall-eyed bilateral internuclear ophthalmoplegia) secondary to ischemic stroke, about a case

WEBINO (wall-eyed bilateral internuclear ophthalmoplegia) syndrome is characterized by bilateral adduction impairment, nystagmus of the abducting eye, and primary gaze exotropia. We present the case of a 68 year-old man who was initially attended in emergency department with sudden onset diplopia. Neurological exploration revealed WEBINO and gait ataxia. Relevant medical history included liver transplantation and subsequent tacrolimus prescription. Complementary exams revealed ischemic lesion in mesencephalic tegmentum, involving medial longitudinal fasciculus and pretectal area. WEBINO syndrome is unfrequent. Among its etiologies, ischemic and demyelinating are the most frequent. In our case, iatrogenic etiology was also considered. Clinical recognition of this syndrome is required to perform adequate exams in order to reach diagnosis.

Binocular, Accommodative and Oculomotor Alterations In Multiple Sclerosis: A Review

Multiple sclerosis (MS) is an acquired demyelinating and inflammatory neurodegenerative disease affecting the central nervous system (CNS). Clinical and subclinical ocular disturbances occur in almost all patients with MS. The objective of this narrative review was to collect and summarize the available scientific information on oculomotor, accommodative and binocular alterations that have been reported in MS. A systematic search strategy with the following descriptors was carried out: multiple sclerosis, ocular motility disorders, internuclear ophthalmoplegia, nystagmus, vergences, fixation, pupil reflex, accommodation and stereopsis. According to the search, some oculomotor alterations were found to be commonly reported in MS, such as alterations in saccades and nystagmus. In contrast, accommodative, vergence and stereopsis alterations have not been comprehensively studied despite their relevance, with only minimal evidence showing a potential negative impact of the disease on these aspects. In conclusion, oculomotor impairment is a common component of disability in MS patients and should be considered when managing this type of patients. More research is still needed to know the real impact of this disease on binocular vision and accommodation.

Sixteen-and-a-half syndrome with metastatic pons tumor: A case report

RATIONALE

One-and-a-half syndrome (OAAH) is characterized as the combination of ipsilateral horizontal gaze palsy and internuclear ophthalmoplegia. OAAH syndrome accompanied with 7th and 8th cranial nerve palsy is called 16-and-a-half syndrome. We aimed to report the case of 16-and-a-half syndrome with metastatic pons tumor.

PATIENT CONCERNS

A 57-year-old male diagnosed with nonsmall-cell lung cancer (NSCLC) with brain metastasis occurring 15 months ago was referred to our clinic with the chief complaint of horizontal diplopia and right gaze palsy.

DIAGNOSIS

According to the patient symptom, ocular examination, and radiographic findings, he was diagnosed as 16-and-a-half syndrome which was caused by brain tumor metastasis from NSCLC.

INTERVENTIONS

We referred him to hemato-oncology department and he was treated with radiation and supportive therapy.

OUTCOMES

Unfortunately, the patient passed away 1 month later without improvement of ophthalmoplegia.

LESSONS

The clinical findings of our case indicate 16-and-a-half syndrome caused by brain tumor metastasis from NSCLC, which to our knowledge has not been previously reported. The case highlights a rare cause of OAAH spectrum disease and the importance of a systemic work-up including associated neurologic symptoms and brain imaging in patients with horizontal gaze palsy.

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’.