A potential new brainstem reflex: The oculoglossal phenomenon

Background: A synchronized involuntary movement of the tongue to the same side as voluntary movements of the eyes, termed the oculoglossal phenomenon, has been observed. A description of the hypothesized pathway of this phenomenon could guide the development of a rapid clinical evaluation of the long segment of the brainstem and help facilitate further studies to establish a new reflex, if possible. The aim of this study is to describe and propose the simple concept of this pathway/phenomenon, the oculoglossal phenomenon. Methods: This is an observational study. Of a newly observe brainstem phenomenon evaluated on a subject at the National Neuroscience Institute in king Fahad Medical City (KFMC), Riyadh, Saudi Arabia. After being observed incidentally in a single patient, 60 participants were tested between January and March 2020 to confirm the presence of the phenomenon. Each subject was instructed to protrude the tongue and then move their eyes horizontally to the side. If the tongue simultaneously and involuntarily moved to the same side as the eyes, the test was deemed confirmatory. A literature review was performed, and possible anatomical pathway was proposed. Results: The oculoglossal reflex was present in most (50/60, 83.3%) of the subjects. Our proposed pathway begins at the frontal cortex, followed by a projection to the paramedian pontine reticular formation, then to the contralateral medial longitudinal fasciculus and bilaterally to the hypoglossal nuclei. Conclusion: An accurate description of this phenomenon could lead to additional studies and possibly establishing it as a legitimate reflex, thus conceivably adding a new tool in the neurological examination to evaluate the brainstem’s integrity.

A Case Report of Classical eight-and-a-Half Syndrome and Etiology Analysis

Eight-and-a-half syndrome is one-and-a-half syndrome plus ipsilateral seventh (facial) cranial nerve palsy, which was first reported by Eggenberger in 1998. This syndrome is caused by a lesion (most often vascular or demyelinating) in the dorsal tegmentum of the caudal pons. It involves the para pontine reticular formation and the medial longitudinal fasciculus, as well as the nucleus and the fasciculus of the facial nerve. We describe a case of a 56-year-old man presented with eight-and-a-half syndrome. We also discuss the vascular pathology and etiology of this syndrome through the literature review. Most eight-and-a-half syndrome cases are caused by occlusions of the perforating branches of the pons. The pathology can be transparent lipid-like changes at the perforator arteries. It can also be thrombosis at the orifice of the main or perforator arteries. BAH could be a very important factor in perforator artery infarction at the pontine. The etiology is closely related to hyperglycemia. An effective intervention is to avoid bad habits and control the hyperglycemia.

“Nine Syndrome”: A Rare Neuroophthalmological Syndrome Associated with HIV Vasculopathy

There are many named brainstem syndromic variants of medullary infarcts among which “eight-and-a-half” syndrome is a rare condition that involves ipsilateral abducens nucleus or paramedian pontine reticular formation, ipsilateral medial longitudinal fasciculus, and adjacent facial colliculus/facial nerve. Here, we describe a new variant of brainstem syndrome, which includes the clinical features of “eight-and-a-half syndrome” with associated hemiparesis. This patient is a known case of HIV illness since 6 years on antiretroviral therapy, presented with features of “Nine” syndrome.

Complete horizontal gaze palsy due to bilateral paramedian pontine reticular formation involvement as a presentation of multiple sclerosis: a case report

Background Demyelinating central nervous system diseases include several disorders that multiple sclerosis (MS) is identified as the most common among them. Ocular movement disturbances are a typical presentation in MS patients where lesions affect the complex and interconnected pathways involved in eye motion. Centers for gaze control are located in the pons primarily; therefore, lesions involving these centers can be presented with abnormalities in gaze. However, bilateral lesions in pontine gaze centers are exceptionally rare. Case presentation A 16-year-old girl with bilateral horizontal gaze palsy was referred to the neurology clinic. Magnetic resonance imaging of the patient indicated bilateral hyperintensities in the pons at the level of the paramedian pontine reticular formation. The patient was diagnosed with multiple sclerosis with respect to clinical and imaging findings and managed. Conclusion Ocular movement abnormalities are a commonly encountered manifestation in patients with multiple sclerosis, however, bilateral gaze palsy is an exceptionally rare sign and should guide the physician to contemplate for anticipated lesions in the pons, and suspect MS, especially in childbearing-aged women. Although an extensive workup should also be done to rule out possible mimickers.