Artery of Percheron Ischaemic Stroke: A Classic Presentation of a Rare Case

The artery of Percheron (AoP) is a rare anatomic variant, where the paramedian thalami and the rostral midbrain are supplied by an artery emerging from the P1 segment of the posterior cerebral artery. Ischaemic infarction of the artery of Percheron occurs rarely, accounting for 0.1 to 2% of all ischaemic strokes. AoP occlusion can lead to an infarction of the paramedian thalami and mesencephalon, resulting in a triad of clinical features; namely, altered mental status, vertical gaze palsy and memory impairment. A larger mesencephalon infarction can also feature oculomotor disturbances. We describe here the case of an 88-year-old patient, presenting with this triad of features.

The Compatibility between the Takeover Process in Conditional Automated Driving and the Current Geometric Design of the Deceleration Lane in Highway

In recent years, the takeover process of conditional automated driving has attached a great deal of attention. However, most of the existing research has focused on the effects of human-machine interactions or driver-related features (e.g., non-driving-related tasks), while there is little knowledge about the compatibility between the takeover process and existing road geometric design. As there is a high possibility that drivers must take over the vehicle before they diverge from the mainline of the highway, this explanatory study aimed to examine the compatibility between the takeover process and the current deceleration lane geometric design. The distribution range of existing deceleration lanes’ lengths were obtained through a geo-based survey. Nine scenarios were recreated in the driving simulator which were designed with various deceleration lane lengths and driving modes (different takeover time budgets and manual driving as the baseline group). A total of 31 participants were recruited to take part in the experiment, their gaze behaviors were recorded simultaneously. Results showed that, compared with manual driving, both drivers’ horizontal and vertical gaze dispersion increased, while drivers adopted higher deceleration in the mainline and merged into the deceleration lane later under takeover conditions. Moreover, a longer deceleration lane could benefit vehicle control. However, its marginal effect was reduced with the increase of deceleration lane length. These findings can help automated vehicle manufacturers design dedicated takeover schemes for different deceleration lane lengths.

Case Report: Isolated, unilateral oculomotor palsy with anti-GQ1b antibody following COVID-19 vaccination

Neurological complications following vaccinations are extremely rare, but cannot be eliminated. Here, we report the first case of unilateral oculomotor nerve palsy (ONP) with anti-GQ1b antibody after receiving the Pfizer-BioNTech COVID-19 (BNT162b2) mRNA vaccine. A 65-year-old man developed diplopia and ptosis in the right eye 17 days after vaccination, without preceding infection. Neurological examination revealed mild blepharoptosis, limitation of adduction, and vertical gaze on the right side. Increased levels of anti-GQ1b ganglioside antibody in the serum and albuminocytologic dissociation in the cerebrospinal fluid were detected. Cranial magnetic resonance imaging showed swelling and enhancement of the right oculomotor nerve. The patient was diagnosed with right ONP accompanied with anti-GQ1b antibody, and intravenous immunoglobulin (IVIG) therapy for 5 days was administered. The limitation of adduction and vertical gaze improved, and ptosis markedly resolved after IVIG treatment. Given the temporal sequence of disease progression, laboratory findings, and a favorable response to IVIG, a causal relationship cannot be ruled out between the occurrence of ONP and COVID-19 immunization. Since immunomodulatory treatments significantly hasten the recovery and minimize the residual symptoms in anti-GQ1b antibody syndrome, clinicians should be aware of this clinical condition following COVID-19 vaccination.

Wall-eyed bilateral internuclear ophthalmoplegia in posterior circulation stroke-a case report

Internuclear ophthalmoplegia is characterised by restricted ocular motility in lateral gaze in which the affected eye shows impairment of adduction and it results from damage to medial longitudinal fasciculus (MLF). Wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) is an extremely rare neurological manifestation which has typical signs including primary gaze exotropia, vertical gaze palsy, ptosis, abducting nystagmus. The common and serious etiological factor is cerebrovascular accident involving the vessels supplying MLF and many cases have life threatening associated neurological impairment. In this case report we have discussed about a gentleman who presented with bilateral ptosis, primary gaze exotropia and headache. Patient found to have vertical gaze palsy and abducting nystagmus on examination. Computed tomography (CT) imaging shows infarct in pontine region and CT angiography revealed basilar artery occlusion supplying region of pons with involvement of posterior cerebral artery. Patient treated with antiplatelet and diplopia managed. Patient showed improvement on subsequent follow-up visits.

Distinct purinergic receptor-mediated currents of rat oculomotor integrator neurons characterized by different firing patterns

The roles of purinergic signaling on vertical (mediated by the interstitial nucleus of Cajal; INC) and horizontal (prepositus hypoglossal nucleus; PHN) gaze control are not understood. Here, we report three current types induced by ATP in INC neurons; the distribution of these current types across different types of INC neurons is different from that in PHN neurons. These results suggest distinct modes of purinergic modulation in horizontal and vertical gaze control centers.

Occipital posterior interhemispheric supratentorial approach for resection of midbrain cavernous malformation

Approaches to the pineal region are various, and each has its advantages and disadvantages. The authors present a case of a 50-year-old woman who presented with progressive hemiparesis and vertical gaze palsy; she was diagnosed with a midbrain cavernous malformation. The patient underwent an occipital posterior interhemispheric supratentorial transpineal approach with gross-total resection. On long-term follow-up, her symptoms significantly improved. The authors review the regional anatomy and present the operative video. They also discuss the various approaches with their indications, advantages, and disadvantages. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2133.

Acute Percheron Infarction: A Precision Learning

Background: So far, the diagnosis of acute AOP infarction is uncommon. The purpose of our study was to characterize the relationship between the imaging spectrum of acute AOP infarction and its clinical manifestations and prognosis on the basis of 23 cases.Methods: A total of 23 patients with acute AOP infarction in our institution from 2014 to 2019 were reviewed retrospectively. All cases were evaluated with computed tomography (CT), magnetic resonance imaging (MRI), detailed clinical and evaluated prognosis used a modified Rankin scale (mRs), blood studies, electrocardiogram and transthoracic echocardiography. All standard risk factors were recorded in these patients. mRs scores 90 days after discharge. Results: We identified 4 various patterns of acute AOP infarction: (1) bilateral paramedian thalamic infarction (BPTI, 52%), (2) bilateral paramedian thalamic with rostral midbrain infarction (BPTRMI, 30%), (3) bilateral paramedian and anterior thalamic infarction (BPATI, 13%), and (4) bilateral paramedian thalamic with red nuclei infarction (BPTRNI, 4%). These patients had consciousness disorder, memory dysfunctions, vertical gaze paresis, mesencephalothalamic syndrome and so on. The 65% patients with BPTI and BPATI who experienced a good functional recovery and could carry out daily life activities (mRS score ≤ 2). However, patients with BPTRMI who have an unfavorable outcome.Conclusion: Although the clinical feature of patients with AOP infarction is variable, DWI or ADC map can improve the diagnosis of acute AOP infarction patterns. Acute AOP occlusion requires immediate diagnosis and treatment initiation for a more favorable outcome and additional unnecessary procedures.

Improvement in mild anti-IgLON5 encephalopathy without immunotherapy: a case report

Background Anti-IgLON5 antibody-related encephalopathy is a recently discovered and rare autoimmune disease, and its diagnosis and treatment are more challenging than for other autoimmune encephalopathic diseases. Sleep disorder is the most prominent symptom of the disease. It can also present with gait instability, dysarthria, dysphagia, dementia, ataxia, autonomic nervous system dysfunction, chorea, vertical gaze paralysis, and other symptoms. Immunotherapy remains the primary treatment for this disease; however, there is no definitive conclusion regarding the effect of immunotherapy. The clinical symptoms of the reported cases of anti-IgLON5 antibody-related encephalopathy were generally severe. However, the symptoms in our patient were mild and relieved without immunotherapy, unlike the previously reported cases. Case presentation A 62-year-old man presented with behavioural abnormalities and involuntary movements after nearly 2 months of fever and headache. He also had symptoms of mild sleep disorder. Due to the abnormal levels of infection-related indicators, antiviral treatment was started on the day of admission. The serum analysis confirmed the presence of IgLON5 antibody, and the patient was found to be genetically susceptible. The patient’s symptoms resolved rapidly without immunotherapy and did not recur. Conclusions This case demonstrated that IgLON5 antibody-related encephalopathy might have mild manifestations. Infection and a genetic predisposition may be important causes for the disease. Patients with a mild disease may have a better prognosis.

Syndrome of one and middle of the vertical look: possible clinical entity associated with percheron artery ischemia: semiological and neuroanatomic aspects

Context: The acute paralysis of the vertical gaze is usually caused by a mesencephalic lesion because the control of the vertical conjugated gaze is found there; there are three main structures: the rostral interstitial nucleus of the medial longitudinal fascicle (riFLM), the Cajal interstitial nucleus and the posterior commissure (CP). The riFLM, contains burst neurons responsible for the saccades, projecting to the subnuclei of the upper rectum and inferior oblique to look upwards and subnuclei of the lower rectum and superior oblique to look downwards. The projections for the elevators appear to be bilateral, with axons probably crossing within the oculomotor nuclear complex and apparently not via CP; depressors, on the other hand, are ipsilateral. Case report: Female, 78 years old, hypertensive and diabetic, suddenly started with vertical diplopia and vertigo. Examination: Bilateral hypoactive photomotor reflex, bilateral paralysis of the vertical gaze upward, monocular paralysis downward and torsional nystagmus in the left eye. Resonance with restriction the diffusion of water molecules in both thalamus and in the right rostral midbrain. Conclusions: riFLM is vascularized by the posterior thalamus-subthalamic paramedian artery. A single artery, Percheron’s, provides both riFLM in 20% of the population and allows bilateral lesions from a single infarction. Unilateral infarction can also cause saccadic paralysis of the bilateral vertical gaze. The disjunctive disorders of the vertical gaze have two variants of the one and a half syndrome. One consists of bilateral paralysis of the gaze upwards and monocular paresis of the gaze downwards with an ipsilateral or contralateral lesion, described in thalamomesencephalic lesions, explanation for the exposed case. The other is due to bilateral mesodiencephalic infarctions. It is difficult to understand the relationship between topography and the vertical gaze circuit, showing that it is more complex than we imagine. It is probably an association of topographies, little described, but of paramount importance to be discussed and researched.