Gaze Palsy Research Articles

A novel homozygous frameshift mutation in the DCC gene in a Pakistani family with autosomal recessive horizontal gaze palsy with progressive scoliosis-2 with impaired intellectual development.

Horizontal Gaze Palsy with Progressive Scoliosis-2 with Impaired Intellectual Development (HGPPS2) is a rare congenital disorder characterized by absence of conjugate horizontal eye movements, and progressive scoliosis developing in childhood and adolescence. We report three new patients with HGPPS2 in a consanguineous Pakistani family, presenting varying degrees of progressive scoliosis, developmental delays, horizontal gaze palsy, agenesis of corpus callosum, and absence of cerebral commissures. Analysis of genotyping data identified shared loss of heterozygosity (LOH) region on chromosomes 5p15.33-15.31, 6q11.2-12, and 18q21.1-21.3. A hypothesis-free, unbiased exome data analysis detected an insertion of nucleotide A (c.2399dupA) in exon 16 of the DCC gene. The insertion is predicted to cause frameshift p.(Asn800Lysfs*11). Interestingly, DCC gene is present in the LOH region on chromosome 18. Variant (c.2399dupA) in the DCC gene is considered as the most probable candidate variant for HGPPS2 based on the presence of DCC in the LOH region, previously reported role of DCC in HGPPS2, perfect segregation of candidate variant with the disease, prediction of variant pathogenicity, and absence of variant in variation databases. Sanger Sequencing confirmed the presence of the novel homozygous mutation in all three patients; the parents were heterozygous carriers of the mutation, in accordance with an autosomal recessive inheritance pattern. DCC encodes a netrin-1 receptor protein; its role in the development of the CNS has recently been established. Biallelic DCC mutations have previously been shown to cause HGPPS2. A novel homozygous variant in patients of the reported family extend the genotypic and phenotypic spectrum of HGPPS2.

Visual Perception: Attending beyond the Eyes’ Reach

It has been long debated whether visual attention can shift covertly, decoupled from programming eye movements. Now we know that patients with gaze paralysis show conventional benefits of exogenous (involuntary) attention, confirming that covert attention is not driven by oculomotor programming.

Genetics of Progressive Supranuclear Palsy: A Review.

Progressive supranuclear palsy (PSP) is an atypical parkinsonism with prominent 4R-tau neuropathology, and the classical clinical phenotype is characterized by vertical supranuclear gaze palsy, unprovoked falls, akinetic-rigid syndrome and cognitive decline. Though PSP is generally regarded as sporadic, there is increasing evidence suggesting that a series of common and rare genetic variants impact on sporadic and familial forms of PSP. To date, more than 10 genes have been reported to show a potential association with PSP. Among these genes, the microtubule-associated protein tau (MAPT) is the risk locus with the strongest effect size on sporadic PSP in the case-control genome-wide association studies (GWAS). Additionally, MAPT mutations are the most common cause of familial PSP while the leucine-rich repeat kinase 2 (LRRK2) is a rare monogenic cause of PSP, and several other gene mutations may mimic the PSP phenotype, like the dynactin subunit 1 (DCTN1). In total, 15 MAPT mutations have been identified in cases with PSP, and the mean age at onset is much earlier than in cases carrying LRRK2 or DCTN1 mutations. GWAS have further identified several risk loci of PSP, proposing molecular pathways related to PSP. The present review focused on genetic studies on PSP and summarized genetic factors of PSP, which may help to elucidate the underlying pathogenesis and provide new perspectives for therapeutic strategies.

Novel mutations in ATP13A2 associated with mixed neurological presentations and iron toxicity due to nonsense-mediated decay

BackgroundKufor-Rakeb Syndrome (KRS) is an autosomal recessive disease characterized by Parkinsonism, pyramidal signs, dementia, and supranuclear gaze palsy. KRS is caused by mutations in ATP13A2producing a transmembrane protein responsible for the regulation of intracellular inorganic cations. ObjectiveTwo siblings born to a Turkish family of consanguineous marriage had mixed neurological presentations with the presence of hypointense images on T2-weighted MRI and were pre-diagnosed as having autosomal recessive spastic paraparesis or ataxia.We aimed to identify the disease-causing mutation by whole-exome sequencing and elucidate the underlying molecular mechanism of the causative mutation. MethodsPrussian blue staining was conducted for the detection of cellular iron accumulation. Disease-causing mutation inATP13A2was detected by whole-exome sequencing. Expression levels of ATP13A2 mRNA and protein were assessed by qRT-PCR and Western Blot. ResultsIron deposits in the patients’ fibroblasts were detected by Prussian blue staining. Novel homozygous mutation c.1422_1423del:p.P474fs was detected intheATP13A2. As this mutation caused a premature termination codon (PTC), the expression of mutant ATP13A2 mRNA through qRT-PCR analysis was found to be degraded by nonsense-mediated decay and this prevented the expression of ATP13A2 protein in the patients’ fibroblasts. ConclusionsNovel frameshift mutation causing a PTC in ATP13A2 lead to degradation of ATP13A2 mRNA by NMD. Iron accumulation due to the absence of ATP13A2 protein in the patient’s fibroblasts and hypointense areas on T2-weighted images may expand the spectrum of KRS to consider it as neurodegeneration with brain iron accumulation disorders.

After stroke, apraxia of eyelid opening is associated with high mortality and right hemispheric infarction

IntroductionApraxia of eyelid opening (AEO) refers to impaired voluntary eyelid elevation of supranuclear origin. AEO is well-described in neurodegenerative disorders, but its frequency in stroke is unknown. MethodsTo investigate the frequency of AEO after stroke, we enrolled patients with an anterior circulation occlusion admitted for endovascular thrombectomy (EVT). Exclusion criteria were posterior circulation stroke, impaired consciousness and ophthalmological disorders. Forty-eight hours after EVT, patients were screened for AEO, conjugated gaze palsies and cortical ptosis. Neurological deficits were classified using the National Institute of Health Stroke Scale (NIHSS). A blinded neuroradiologist analyzed CT brain 24 h after EVT using the Alberta Stroke Program Early CT Score. ResultsNinety-eight EVT patients were included in 9 months. Six patients had AEO (6%), 37 conjugated gaze palsy (38%) and 16% cortical ptosis (16%). AEO was associated with higher median NIHSS compared to no eye symptoms (18.5 vs. 3; p < 0.001) and gaze palsy or cortical ptosis (18.5 vs. 7; p = 0.003). The median modified Rankin Scale (mRS) after 3 months was 2 in patients without AEO, but 6 in patients with AEO (mRS in AEO patients nr. 1–6: 3, 4, 6, 6, 6, and 6; p = 0.015; no longer significant after adjustment for stroke severity), including 4 deaths (66%) in AEO patients. All patients with AEO had right hemisphere stroke (6/6 vs. 43/98 in total, p = 0.006). ConclusionAEO was observed in 6% of EVT patients who showed poor survival and outcome. AEO occurred exclusively in right hemispheric infarctions, suggesting that supranuclear eyelid control is under the influence of the right cerebral hemisphere.

Tension Pneumocephalus in a Tracheostomized, Chronically Ventilated, Duchenne’s Muscular Dystrophy Patient Without Prior Head Trauma

Tension pneumocephalus is a rare condition that can be a life-threatening neurosurgical emergency. It usually results from head trauma, but there have been case reports of iatrogenic causes including on non-invasive mechanical ventilation. We report a case of pneumocephalus resulting from high mechanical ventilation pressures in a patient without prior head trauma.A 37-year-old male with Duchenne’s muscular dystrophy who had been ventilator-dependent through tracheostomy was admitted for shortness of breath and intermittent fevers. The patient was found to have pneumonia, with left-lower lobe consolidation, and was started on linezolid given known Methicillin-resistant Staphylococcus aureus from previous sputum culture; he was later switched to vancomycin and piperacillin-tazobactam given persistent fevers to cover for hospital-acquired pneumonia. The patient went into septic shock requiring multiple pressors as well as stress steroids for persistent shock, with eventual improvement in hemodynamics. He developed further respiratory acidosis on his usual ventilator settings, and peak inspiratory pressures (PIPs) progressively increased to as high as 45-70 cm H2O during his hospital course. PIPs did not improve with suctioning or after bronchoscopy. On the 17th day of the patient’s stay, he had acutely altered mental status with non-reactive fixed and dilated pupils and disconjugate gaze of the right eye on neurologic examination. CT of the head at that time revealed extensive pneumocephalus along the bifrontal convexities, suprasellar cisterns, and posterior fossa, with a possible fracture of the frontal skull base near the ethmoid roof. Mount Fuji sign was present on CT scan, indicative of “tension pneumocephalus”. Neurosurgical consultation was obtained but the family declined intervention given his overall debilitated stated. Comfort measures were instituted, and the patient expired the following day.Pneumocephalus is the accumulation of air entry into the cranial cavity, generally from head trauma, inflammation, or surgery. Patients may have underlying base skull defects or microfractures that permit air to enter the intracranial cavity. Increased sphenoid sinus pressure from mechanical ventilation may enter the subperiosteal space, allowing air to enter the intracranial cavity. It is important to consider pneumocephalus in a patient with new neurological findings after mechanical ventilation.

Identification of a novel mutation in ATP13A2 associated with a complicated form of hereditary spastic paraplegia.

ObjectiveTo establish molecular diagnosis for a family with a complicated form of autosomal recessive hereditary spastic paraplegia with intellectual disability, cognitive decline, psychosis, peripheral neuropathy, upward gaze palsy, and thin corpus callosum (TCC).MethodsPhysical examinations, laboratory tests, structural neuroimaging studies, and exome sequence analysis were carried out.ResultsThe 3 patients exhibited intellectual disability and progressive intellectual decline accompanied by psychiatric symptoms. Gait difficulty with spasticity and pyramidal weakness appeared at the ages of 20s–30s. Brain MRI revealed TCC with atrophic changes in the frontotemporal lobes, caudate nuclei, and cerebellum. Exome sequence analysis revealed a novel homozygous c.2654C>A (p. Ala885Asp) variant in the ATP13A2, a gene responsible for a complicated form of hereditary spastic paraplegia (SPG78), Kufor-Rakeb syndrome, and neuronal ceroid lipofuscinosis. The predominant clinical presentations of the patients include progressive intellectual disability and gait difficulty with spasticity and pyramidal weakness, consistent with the diagnosis of SPG78. Of note, prominent psychiatric symptoms and extrapyramidal signs including rigidity, dystonia, and involuntary movements preceded the spastic paraparesis.ConclusionsOur study further broadens the clinical spectrum associated with ATP13A2 mutations.

Author response: Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI2AA).

We appreciate the comments and insights of Grewal and Goldstein on our article.1 As for atrial fibrillation (AF), it has the weakest relation with large vessel occlusion (LVO) (logit [probability of the occlusion] = 3.3 [gaze palsy, aphasia, or inattention [GAI]] + 1.5 [arm paresis] + 1.3 [AF] − 4.4 + e), and the prevalence may vary between the patient groups. In our GAI2AA scale (pronounced “gaia,” who is the Greek goddess of the earth), the addition of AF was intended to reinforce the diagnosis of LVO. If the patients with hemispheric symptoms and arm paresis also have the sign of AF, it not only shows the more probability of an LVO but also with typical cardioembolic origin.

Reader response: Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI2AA).

I highly appreciate the present study,1 in which a newly developed simple scale for prediction of large vessel occlusion (LVO) in anterior circulation has undergone internal single center—and external multicenter—validation and comparison with previously published clinical scales. Novelties of the GAI2AA scale are the combined scoring of gaze palsy, aphasia, and inattention, and the addition of the subitem atrial fibrillation.

Editors' note: Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI 2 AA)

Editors' note: Optimizing in-hospital triage for large vessel occlusion using a novel clinical scale (GAI ₂ AA)

Neuropathology of Cerebellar Cortical Atrophy

Cerebellar cortical atrophy (CCA) is a neurodegenerative disease characterized by the loss of Purkinje cells, frequently associated with atrophy of the inferior olivary nucleus. The diagnosis of CCA requires a pathologic assessment; however, this term has also been used in clinical practice as a diagnosis of exclusion for sporadic, adult-onset, and progressive ataxia. For the clinical diagnosis of CCA, diagnostic criteria for idiopathic cerebellar ataxia (IDCA) have been proposed. We herein describe two patients with a pathologic diagnosis of CCA. The first patient was clinically suspected to have Creutzfeldt-Jakob disease due to rapid progressive dementia and ataxia. The second patient was clinically diagnosed with progressive supranuclear palsy based on imbalance, frequent falls, and vertical gaze palsy. The se cases suggest that the clinical presentation of CCA is heterogeneous, and CCA does not always meet the criteria for IDCA. Therefore, the term CCA should be used solely for a pathologic diagnosis.

Artery of Percheron infarction presenting as nuclear third nerve palsy and transient loss of consciousness: a case report

BackgroundThalamic blood supply consists of four major vascular territories. Out of them paramedian arteries supply ipsilateral paramedian thalami and occasionally rostral mid brain. Rarely both paramedian arteries arise from a common trunk that arise from P1 segment of one sided posterior cerebral artery (PCA). This is usually due to hypoplastic or absent other P1 and this common trunk is termed Artery of Percheron (AOP). Its prevalence is in the range of 7–11% among the general population and AOP infarcts account in an average of 0.4–0.5% of ischemic strokes. Clinical presentation of AOP infarction is characterized by impaired arousal and memory, language impairment and vertical gaze palsy. It also can present with cerebellar signs, hemi paresis and hemi sensory loss. We herein present a case of AOP infarction presenting as transient loss of consciousness and nuclear third nerve palsy.Case presentationA 51 year old previously healthy male, was brought to us, with a Glasgow coma scale (GCS) of 7/15. GCS improved to 11/15 by the next day, however he had a persisting expressive aphasia. Right sided nuclear third nerve palsy was apparent with the improvement of GCS. He did not have pyramidal or cerebellar signs. Thrombolysis was not offered as the therapeutic window was exceeded by the time of diagnosis. Diagnosis was made using magnetic resonance imaging (MRI) that was done after the initial normal non-contrast computer tomography (NCCT) brain. He was enrolled in stroke rehabilitation. Aspirin and atorvastatin was started for the secondary prevention of stroke. He achieved independency of advanced daily living by 1 month, however could not achieve full recovery to be employed as a taxi driver.ConclusionsBecause of the rarity and varied clinical presentation with altered levels of consciousness, AOP infarcts are easily overlooked as a stroke leading to delayed diagnosis. Timely diagnosis can prevent unnecessary investigations and the patient will be benefitted by early revascularization. As it is seldom reported, case reports remain a valuable source of improving awareness among physicians about this clinical entity.

Molecular mechanisms regulating axon responsiveness at the midline

During embryonic development in bilaterally symmetric organisms, correct midline crossing is important for the proper formation of functional neural circuits. The aberrant development of neural circuits can result in multiple neurodevelopmental disorders, including horizontal gaze palsy, congenital mirror movement disorder, and autism spectrum disorder. Thus, understanding the molecular mechanisms that regulate proper axon guidance at the midline can provide insights into the pathology of neurological disorders. The signaling mechanisms that regulate midline crossing have been extensively studied in the Drosophila ventral nerve cord and the mouse embryonic spinal cord. In this review, we discuss these axon guidance mechanisms, highlighting the most recent advances in the understanding of how commissural axons switch their responsiveness from attractants to repellents during midline crossing.

Ocular lateral deviation with brief removal of visual fixation differentiates central from peripheral vestibular syndrome.

Ocular lateral deviation (OLD) is a conjugate, ipsilesional, horizontal ocular deviation associated with brief (3-5s) closing of the eyes, commonly linked to the lateral medullary syndrome (LMS). There is limited information regarding OLD in patients with the acute vestibular syndrome (AVS). In one case series 40years ago OLD was suggested to be a central sign. Recently, horizontal ocular deviation on imaging (RadOLD) was frequently associated with anterior circulation stroke and horizontal gaze palsy. Similarly, RadOLD has been associated with posterior circulation stroke, e.g., LMS and cerebellar stroke, but without clinical correlation with OLD. This is a prospective, cross-sectional diagnostic study of 151 acute AVS patients. Patients had spontaneous nystagmus. Horizontal gaze paralysis was an exclusion criterion. We noted the effect of brief 3-5s eyelid closure on eye position, and then used the HINTS algorithm (the head-impulse test, nystagmus characteristics and skew deviation) and RadOLD, to establish a correlation between clinical and radiologic findings RESULTS: Of the 151 AVS patients, 100 had a central lesion and 51 a peripheral lesion; 29 of the central lesions were LMS, and 11 had OLD. Additionally, one lateral pontine syndrome had OLD. On opening the eyes 11 patients with OLD and LMS made multiple, hypometric corrective saccades to bring gaze back to straight ahead. 10/11 patients with LMS showed RadOLD. OLD with multiple hypometric corrective saccades on opening the eyes was infrequent but highly localizing and lateralizing. We emphasize how simple it is to test for OLD, with the caveat that to be specific, it must be present after just brief (3-5s) eyelid closure.

Anti- RI antibody associated progressive supranuclear palsy like presentation in a patient with breast carcinoma

Paraneoplastic neurological syndromes (PNS) are well established entities associated with onconeural antibodies. Paraneoplastic parkinsonism is a highly under narrated presentation of PNS. Rapid progression of typical or atypical parkinsonism with red flags like multiaxial involvement, complete gaze palsy and a clinico-radiological mismatch should prompt a clinician to suspect secondary etiologies like infection, metabolic, vascular, metastatic and paraneoplastic causes. We describe a patient with rapidly progressive parkinsonism. Diagnosis of Breast carcinoma associated ANNA-2/ Anti Ri mediated PSP like phenotype was made in this patient based upon clinical examination and investigations. We also present a review of literature on paraneoplastic parkinsonism in this manuscript.

Introducing and Reviewing a Novel Mutation of ROBO3 in Horizontal Gaze Palsy with Progressive Scoliosis from a Chinese Family

Horizontal gaze palsy with progressive scoliosis (HGPPS) is an autosomal recessive disorder caused by ROBO3 gene mutations. To date, the number of confirmed HGPPS cases caused by gene mutations is estimated at 76. However, HGPPS caused by ROBO3 gene mutation has not been reported in the Chinese population. In this study, the clinical data, brain imaging features, somatosensory evoked potentials (SEP), and ROBO3 gene mutations were obtained for two Chinese patients with HGPPS. The proband was an 11-year-old boy. He developed horizontal eye movement disorder at the age of 1year and scoliosis at the age of 11years. Two eyeballs fixed in the midline position were revealed by neurological examination. A dorsal cleft in the pons and a butterfly-shaped medulla were shown by brain magnetic resonance imaging. Again, most corticospinal bundles did not cross in the brainstem, as revealed by diffusion tensor imaging. SEP confirmed that most somatosensory projections were uncrossed. The proband's 7-year-old brother exhibited similar clinical manifestations and imaging features. The brothers had compound heterozygous mutations c.3165G>A (p.W1055X) and c.955G>A (p.E319K) of the ROBO3 gene. The c.3165G>A mutation is a novel nonsense mutation that has not been previously reported. This study reports the first two cases of HGPPS carrying a novel ROBO3 gene mutation in patients from a Chinese family, thereby expanding the disease spectrum. Reports from the literature show that missense mutation is the most common mutational type in the ROBO3 gene. Early ROBO3 gene detection is required for patients exhibiting early-onset eyeball movement disorder to confirm HGPPS disease.

Horizontal Gaze Palsy with Progressive Kyphoscoliosis.

Horizontal Gaze Palsy with Progressive Kyphoscoliosis.

A Convenient Prognostic Tool and Staging System for Progressive Supranuclear Palsy.

Progressive supranuclear palsy (PSP) causes major disability, shortens life, and as yet has no disease-modifying and little symptomatic treatment. A convenient prognostic tool is needed to assist patients, families, and clinicians in planning care. We calculated times to acquisition of certain disease milestones and death. We followed a cohort of 417 patients with PSP-Richardson syndrome from 1995 to 2016, applying the Progressive Supranuclear Palsy Rating Scale (PSPRS) at each visit. We generated median times to acquisition of 13 milestones using the input variables of sex, onset age, rate of disease progression from motor symptom onset to initial visit, and PSPRS score at the baseline. Of the outcome milestones, 5 were stages of a new, provisional PSP staging system. The other 8 milestones comprised death and disabling levels of cognitive loss, gaze palsy, dysarthria, dysphagia, and gait/balance impairment. We derived median times to milestones, with 25th and 75th percentiles and 95% confidence intervals of the median for baseline PSPRS scores from 25 to 65 (scale range, 0-100). Sex and initial progression velocity significantly influenced the death milestone, but not most of the others. Median time to death ranged from 4.8 years for a man with PSPRS score of 25 and a slow progression velocity from onset to initial visit of 0.51 PSPRS points/month to 1.8 years for a woman with PSPRS 65 and rapid initial velocity of 2.25 points/month. We have created a convenient, inexpensive, noninvasive reference for counseling patients with PSP-Richardson syndrome on approximate time to encountering 13 life-altering disease milestones.

Clinical and Molecular Features of Early Infantile Niemann Pick Type C Disease.

Niemann Pick disease type C (NPC) is a neurovisceral disorder due to mutations in NPC1 or NPC2. This review focuses on poorly characterized clinical and molecular features of early infantile form of NPC (EIF) and identified 89 cases caused by NPC1 (NPC1) and 16 by NPC2 (NPC2) mutations. Extra-neuronal features were common; visceromegaly reported in 80/89 NPC1 and in 15/16 NPC2, prolonged jaundice in 30/89 NPC1 and 7/16 NPC2. Early lung involvement was present in 12/16 NPC2 cases. Median age of neurological onset was 12 (0–24) and 7.5 (0–24) months in NPC1 and NPC2 groups, respectively. Developmental delay and hypotonia were the commonest first detected neurological symptoms reported in 39/89 and 18/89 NPC1, and in 8/16 and 10/16 NPC2, respectively. Additional neurological symptoms included vertical supranuclear gaze palsy, dysarthria, cataplexy, dysphagia, seizures, dystonia, and spasticity. The following mutations in homozygous state conferred EIF: deletion of exon 1+promoter, c.3578_3591 + 9del, c.385delT, p.C63fsX75, IVS21-2delATGC, c. 2740T>A (p.C914S), c.3584G>T (p.G1195V), c.3478-6T>A, c.960_961dup (p.A321Gfs*16) in NPC1 and c.434T>A (p.V145E), c.199T>C (p.S67P), c.133C>T (p.Q45X), c.141C>A (p.C47X) in NPC2. This comprehensive analysis of the EIF type of NPC will benefit clinical patient management, genetic counselling, and assist design of novel therapy trials.

Upward Gaze Palsy: a Valuable Sign to Distinguish Spinocerebellar Ataxias.

Spinocerebellar ataxias (SCAs) represent a large group of heredodegenerative diseases, with great phenotypic and genotypic heterogeneity. However, in the clinical neurological practice, some symptoms and signs might help differentiate the SCAs. This study's aims were to evaluate the frequency of upward gaze palsy (UGP) and investigate its role in assisting in the clinical differentiation of SCAs. We included 419 patients with SCAs (248 with SCA3, 95 with SCA10, 38 with SCA2, 22 with SCA1, 12 with SCA7, and 4 with SCA6). This study compared UGP with other known markers of disease severity-age of onset, disease duration, SARA score, and size of CAG expansion, and also other semiologic features, as bulging eyes. This sign was significantly more prevalent in SCA3 (64.11%), compared with SCA10 (3.16%; p < 0.001) and other SCAs (SCA1, SCA2, SCA7-11.84%; p < 0.001). UGP showed very high sensibility ins SCA3 (92.9), although lacking of specificity (64.1%). The odds ratio (OR) of UGP were also very high, 23.52 (95% CI 12.38-44.69), and was significantly correlated with larger CAG expansions, age, and disease duration in SCA3 patients, but not with age of onset or severity of the ataxic syndrome. This study showed that UGP is highly suggestive of SCA3 and has high sensitivity for the differential diagnosis among SCAs, and it could be of great value for bedside semiologic tool.