Functional correlates of vertical gaze palsy and other ocular motor deficits in PSP: An FDG-PET study

ObjectiveTo determine the functional correlates of vertical gaze palsy and other ocular motor deficits in patients with progressive supranuclear palsy (PSP) using [¹⁸F]fluorodeoxyglucose (FDG-)PET.MethodsTwenty-six patients with PSP underwent clinical examination of vertical gaze combined with FDG-PET scans to assess regional cerebral glucose metabolism as a marker of neuronal activity. Of these, eighteen PSP patients were also investigated by electrical nystagmography to determine horizontal ocular motor deficits. Statistical parametric mapping analyses were performed to correlate regional neuronal activity with ocular motor functions.ResultsIn categorical comparisons, patients with downward gaze palsy showed a significantly reduced glucose metabolism in bilateral anterior cingulate gyrus and right lingual gyrus compared to those without downward gaze palsy. Maximum velocity of horizontal saccades was positively correlated with glucose metabolism of the rostral vermis and lingual gyrus; regional metabolism of oculomotor vermis was associated with peak velocity of the optokinetic reflex. Analysis of smooth pursuit eye movement amplitude and peak velocity of corrective saccades showed positive correlation with metabolism in bilateral inferior parietal lobe and inferior part of the frontal eye field. All paradigms of smooth pursuit showed positive association with glucose metabolism in V5.ConclusionsOcular motor functions in PSP are correlated with neuronal activity in distinct anatomical regions. These include the anterior cingulate gyrus (downward gaze palsy), rostral cerebellum (saccades), oculomotor vermis (optokinetic reflex) and inferior parietal as well as temporal regions and frontal eye field (smooth pursuit). These findings provide a deeper insight into the pathophysiology of PSP-associated ocular motor abnormalities.     

Association between vestibuloocular reflex suppression during smooth movements of the head and attention deficit in progressive supranuclear palsy.

With head movement, suppression of vestibular inputs during visual exploration is necessary not only for reorienting gaze, but also to direct attention to new visual targets. People with progressive supranuclear palsy (PSP) have difficulty suppressing the vestibuloocular reflex (VOR) and it was hypothesized that the magnitude of VOR suppression deficit correlates with the degree of degradation of attention and visuospatial performance. We evaluated cognitive and visuomotor function in 8 subjects with PSP (4 men and 4 women; ages 59-83 years). Gaze control was studied by measuring the accuracy of eye-head coordination during passive vertical and horizontal head-on-trunk movements. Fixation was assessed when subjects viewed either an earth-fixed or head-fixed target. A gaze fixation score (GFS) was calculated to represent the amount of error between eye and head movement in each plane (eye-head root mean square error normalized to the range of head rotation). The vertical but not horizontal GFS during attempted suppression of the VOR was significantly related to attention (r = -0.70; P = 0.05) and visuospatial ability (r = -0.76; P = 0.03). These findings suggest that the ability to suppress the VOR during vertical smooth movements of the head is associated with the magnitude of cognitive deficit in PSP.     

Neurodegenerative disorders mimicking progressive supranuclear palsy: a report of three cases

Progressive supranuclear palsy (PSP) is rarely confused with other parkinsonian disorders once the vertical gaze palsy appears. Corticobasal degeneration is the most common differential diagnostic entity. We describe three cases diagnosed during life as PSP but found to have another neurologic disorder at autopsy. No explanation for the gaze palsies was found in any case.     

Ocular motor abnormalities in progressive supranuclear palsy

Eleven patients, 7 males and 4 females, of progressive supranuclear palsy (PSP) were examined neuro-otologically for the purpose of elucidating the characteristics of ocular motor abnormalities. All cases were admitted to our hospital and age at onset was from 52 to 71 years old, duration of illness was 2 to 11 years. Range of voluntary eye movements and abnormal eye movements including nystagmus were examined on naked eyes and with electronystagmography (ENG). Smooth pursuit movements and saccadic eye movements were tested both horizontally and vertically by using visual tracking method with ENG recordings. Optokinetic nystagmus test and caloric test with visual suppression test were also performed. These neurotological examinations were made repetitively in 5 cases and their progressions were observed. Vertical gaze palsy and convergence palsy were observed in all cases as the initial symptom. In this study downward gaze was more severely disturbed than upward gaze. Using ENG, saccadic eye movements (saccades) were disturbed earlier than smooth pursuit movements. Hypometric saccades and decreased saccadic velocity were common abnormalities. In the later stage of the disease, horizontal eye movements were also disturbed. In four cases bilateral adduction palsy was added to vertical gaze paralysis so that the lesion of the MLF to oculomotor nucleus was suggested to exist. These voluntary eye movements were worsened gradually as the disease progressed. By using ENG we could find so called abnormal eye movements more frequently than the previous reports. Eight patients demonstrated horizontal gaze nystagmus, and rebound nystagmus were observed in four cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Unilateral midbrain infarction causing upward and downward gaze palsy.

We report on a 47-year-old-woman who developed sudden complete loss of vertical saccades, smooth pursuit, and vestibular eye movements bilaterally. MRI revealed a unilateral midbrain infarct involving the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the interstitial nucleus of Cajal (INC) and spared the posterior commissure (PC). The lesion is presumed to have interrupted the pathways involved in vertical gaze just before they decussate, inducing an anatomically unilateral but functionally bilateral lesion. Previous reports of bidirectional vertical gaze palsy have shown lesions involving the PC or both riMLFs. This case is the first to show that a unilateral lesion of the riMLF and the INC that spares the PC may cause complete bidirectional vertical gaze palsy.     

Abnormalities of optokinetic nystagmus in progressive supranuclear palsy

OBJECTIVES: To measure vertical and horizontal responses to optokinetic (OK) stimulation and investigate directional abnormalities of quick phases in progressive supranuclear palsy (PSP). METHODS: Saccades and OK nystagmus were studied in six PSP patients, five with Parkinson's disease (PD), and 10 controls. The OK stimulus subtended 72 degrees horizontally, 60 degrees vertically, consisted of black and white stripes, and moved at 10-50 degrees /s. RESULTS: All PSP patients showed slowed voluntary vertical saccades and nystagmus quick phases compared with PD or controls. Small, paired, horizontal saccadic intrusions (SWJ) were more frequent and larger in PSP during fixation. Vertical saccades were transiently faster at the time of SWJ and horizontal saccades in PSP. During vertical OK nystagmus, small quick phases were often combined with horizontal SWJ in all subjects; in PSP the vector was closer to horizontal. Vertical OK slow phase gain was reduced in PSP but, in most PD patients, was similar to normals. The average position of gaze shifted in the direction of vertical OK stimulus in PSP patients with preserved slow phase responses but impaired quick phases. CONCLUSIONS: Vertical OK responses in PSP show impaired slow phase responses, and quick phases that are slowed and combined with SWJ to produce an oblique vector. SWJ facilitate vertical saccades and quick phases in PSP, but it is unclear whether this is an adaptive process or a result of the disease. A large OK stimulus is useful to induce responses that can be quantitatively analysed in patients with limited voluntary range of vertical gaze.     

Supranuclear gaze palsy and eyelid apraxia in postencephalitic parkinsonism

Summary We describe six patients with clinicopathologically confirmed postencephalitic parkinsonism (PEP) in whom oculomotor abnormalities developed several years after suffering the initial episode of encephalitis lethargica. Four of the cases had vertical supranuclear gaze palsy and two eyelid apraxia, features typically associated with progressive supranuclear palsy (PSP). Our findings indicate that the presence of gaze palsy alone may not be a reliable clinical discriminator between PEP and PSP. Involvement of the dorsal central gray nucleus, nucleus centralis pontis oralis, nucleus dorsal raphe interpositus, rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), nucleus interstitialis of Cajal, nucleus of the posterior commissure, pedunculopontine nuclei and frontal cortex was observed in several of our PEP cases and may contribute to the oculomotor abnormalities in this disorder. Whether the dorsal tegmental nucleus, caudal to the supratrochlear nucleus, severely affected in all our PEP cases, has a role in vertical gaze needs to be further studied.Abbreviations PSP progressive supranuclear palsy - NFTs neurofibrillary tangles - NPTs neuropil threads - riMLF rostral interstitial nucleus of the medial longitudinal fasciculus     

Progressive supranuclear palsy: a clinicopathological study of 21 cases

The symptoms and signs used to diagnose progressive supranuclear palsy (PSP) should be easily identifiable by neuropathologists and neurologists as well as by movement disorder experts. The presence, at the time of death, of symptoms and signs that are used in published clinical criteria for the diagnosis of this disorder was searched for in 21 pathologically confirmed typical PSP cases. The following items, present in at least 80% of pathologically confirmed cases, can be considered as the most accurate clinical data for the diagnosis of PSP: nonfamilial parkinsonism, not improved by l-dopa therapy, with vertical voluntary gaze palsy; postural instability and falls; pseudobulbar palsy and dementia with frontal lobe-like syndrome; and a progressive course of less than 10 years. The definite diagnosis of PSP must be clinicopathological, and these minimal clinical data may be used for this purpose. Received: 16 August 1995 / Revised, accepted: 23 October 1995     

Progressive supranuclear palsy: Electromyographic examinations of eye muscles

Electromyographic examination of vertical and lateral extraocular muscles was carried out in five patients suffering from progressive supranuclear palsy, and incapable of performing voluntary vertical eye movements. No evidence of a lower motor neurone lesion or paradoxical innervation of eye muscles was noted.
Reciprocal inhibition of antagonist vertical muscles though present in oculocephalic (doll's head) stimulation, was incomplete on attempted voluntary movement. This factor is held to be the probable immediate cause of the vertical gaze palsy.     

Dynamic properties of horizontal and vertical eye movements in parkinsonian syndromes

We studied dynamic properties of horizontal, vertical, and oblique eye movements in 23 patients with the following parkinsonian syndromes: idiopathie parkinsonism (PD), multiple system atrophy (MSA), pure akinesia (PA), progressive supranuclear palsy (PSP), and cortical-basal ganglionic degeneration (CBGD). Compared with age-matched controls, only PSP patients showed slowing of saccades. Patients in all groups showed saccadic hypometria that was most marked vertically. The trajectories of saccades made to diagonal target jumps were deviated toward the horizonal plane, due to the vertical hypometria; this was most marked in PA and PSP groups. Saccade latency was only increased in the CBGD group. Sinusoidai smooth pursuit did not differentiate between controls and patients; however, with step-ramp stimuli, pursuit eye acceleration was impaired in all patient groups compared with controls. The vestibulo-ocular reflex, with or without visual enhancement, was similar in patients and controls. These findings indicate that (1) in parkinsonian syndromes apart from PSP, the saccade-generating brainstem burst neurons are probably spared, but the signals that they receive, specifying the size and direction of saccades, are flawed; and (2) measurements of the gain and trajectory of oblique saccades, and initiation of smooth pursuit, may aid in diagnosing these different types of parkinsonism.     

Bilateral internuclear ophthalmoplegia in progressive supranuclear palsy with an overriding oculocephalic maneuver.

We present a patient with progressive supranuclear palsy (PSP) who had a bilateral internuclear ophthalmoplegia (INO) that could be fully overcome by the oculocephalic maneuver. In addition to being an unusual finding in the clinical setting of PSP, this phenomenon has interesting implications for the functional control of conjugate horizontal gaze.     

Progressive supranuclear palsy and Parkinson's disease overlap: A clinicopathological case report

We describe a woman with a 13‐year history of postural instability, vertical gaze palsy and dopa‐responsive parkinsonism ‐ a clinical profile that corresponds to progressive supranuclear palsy (PSP) and Parkinson's disease (PD). The patient died at the age of 82 years. Neuropathological features included neuronal loss and gliosis in the substantia nigra, locus ceruleus, dorsal motor nucleus of the vagus, thoracic intermediolateral nucleus and nucleus basalis of Meynert, in addition to the typical pathology of PSP. Immunohistochemical studies demonstrated that PSP‐tau pathology was localized in the central nervous system, but Lewy body‐related α‐synucleinopathy was extensive in the central and peripheral nervous systems. Although PSP and PD may represent independent processes, this case could provide insight into a common defect in either protein phosphorylation or the proteinase surveillance system that contributes to human aging.     

Autonomic dysfunction in patients with progressive supranuclear palsy

The most important features that characterize and differentiate progressive supranuclear palsy (PSP) from other parkinsonian syndromes are postural instability, supranuclear gaze palsy, pseudobulbar palsy, and cognitive disturbances. Although it has been reported that significant autonomic dysfunction is an exclusionary feature for PSP diagnosis, we could demonstrate in this study using semiquantitative clinical interview and cardiovascular testing that both PSP and idiopathic Parkinson's disease (PD) patients can present with significant autonomic dysfunction. The parasympathetic cardiovascular system seems to be involved to a similar extent in PD and PSP patients, whereas sympathetic cardiovascular dysfunction is more frequent and severe in PD patients, but can also be found in PSP patients. Our findings have a profound implication on the diagnosis and treatment of PSP patients. © 2008 Movement Disorder Society     

Progressive supranuclear palsy - 20 years later

Reviewing the literature since recognition of progressive supranuclear palsy (PSP) as a clinicopathological entity 20 years ago, the present state of knowledge is delineated. The etiology of PSP is still unknown. The clinical hallmarks are supranuclear palsy of vertical gaze, axial dystonia in extension and pseudobulbar palsy with marked dysarthria and dysphagia. Accessory features include subcortical dementia, mental, extrapyramidal, pyramidal and cerebellar symptoms. PSP is a disease of the presenium (average age at onset, 59.6 years) with a male preponderance (60% men). The onset is insidious with vague complaints of dysequilibrium (60%), mental changes (46%) and disturbed vision (21%), often preceding abnormal neurological findings. The important borderland and main differential diagnosis is parkinsonism. However, in PSP, responsiveness to antiparkinsonian agents is poor and progression is rapid and fatal within few years (average survival time, 5.7 years). Promising diagnostic tools at present include CT-scanning and neuro-otologic and -ophthalmologic examination. Neuropathological findings, confined to specific diencephalic, brainstem and cerebellar nuclei, include neurofibrillary tangles (ultrastructurally different from those seen in other CNS disorders), neuron loss and gliosis. The importance of research on neurocytochemistry, brain ultrastructure and immunology in the current investigation of PSP is outlined.     

Differential diagnostic value of eye movement recording in PSP-parkinsonism,Richardson's syndrome,and idiopathic Parkinson's disease

Abstract   Vertical gaze palsy is a highly relevant clinical sign in parkinsonian syndromes. As the eponymous sign of progressive supranuclear palsy (PSP), it is one of the core features in the diagnosis of this disease. Recent studies have suggested a further differentiation of PSP in Richardson's syndrome (RS) and PSP-parkinsonism (PSPP). The aim of this study was to search for oculomotor abnormalities in the PSP-P subset of a sample of PSP patients and to compare these findings with those of (i) RS patients, (ii) patients with idiopathic Parkinson's disease (IPD), and (iii) a control group. Twelve cases of RS, 5 cases of PSP-P, and 27 cases of IPD were examined by use of video-oculography (VOG) and compared to 23 healthy normal controls. Both groups of PSP patients (RS, PSP-P) had significantly slower saccades than either IPD patients or controls, whereas no differences in saccadic eye peak velocity were found between the two PSP groups or in the comparison of IPD with controls. RS and PSP-P were also similar to each other with regard to smooth pursuit eye movements (SPEM), with both groups having significantly lower gain than controls (except for downward pursuit); however, SPEM gain exhibited no consistent difference between PSP and IPD. A correlation between eye movement data and clinical data (Hoehn & Yahr scale or disease duration) could not be observed. As PSP-P patients were still in an early stage of the disease when a differentiation from IPD is difficult on clinical grounds, the clear-cut separation between PSP-P and IPD obtained by measuring saccade velocity suggests that VOG could contribute to the early differentiation between these patient groups.     

Late-onset frontotemporal dementia associated with progressive supranuclear palsy/argyrophilic grain disease/Alzheimer's disease pathology

Progressive supranuclear palsy (PSP) is typically manifested by vertical supranuclear gaze palsy, frequent falls early in the disease course, axial rigidity and poor response to levodopa. Prominent anterograde memory dysfunction with subsequent impairment in other cognitive domains is characteristic of Alzheimer's disease (AD). No clear clinical syndrome has been identified in argyrophilic grain disease (AGD). Frontotemporal dementia (FTD) is characterized by apathy, emotional blunting, disinhibition, and impairment in executive functioning despite relatively preserved memory and visuospatial abilities. Cognitive deficits are known to occur in PSP; however, overt clinical FTD without parkinsonism or supranuclear gaze palsy associated with PSP pathology has rarely been documented. We report an elderly patient with the typical clinical, neuropsychometric, and neuroimaging features of FTD who had autopsy findings most consistent with PSP plus AGD and AD in limbic structures. We suggest that PSP with or without coexisting AD and AGD be included in the differential diagnosis of patients presenting with FTD.     

A patient with pantothenate kinase-associated neurodegeneration and supranuclear gaze palsy

Pantothenate kinase-associated neurodegeneration (PKAN) is a genetic disease with childhood onset characterized clinically by dystonia, parkinsonism, pyramidal signs, visual failure and mental retardation. Progression is usually relentless culminating in severe disability and death within 15 years of onset. Eye movement abnormalities have been described in patients with PKAN including slowed vertical saccades and saccadic vertical pursuit. We here report a patient with PKAN and supranuclear gaze palsy broadening the phenotypic spectrum of the disease.     

A case of left third nerve palsy and contralateral vertical gaze palsy with medial midbrain infarction]

An 81-year-old man developed oculomotor nerve palsy of the left eye and vertical gaze palsy of the right eye due to left medial midbrain infarction. His left eyelid was ptotic and the pupil was dilated. His right eye showed normal horizontal movement and Bell's phenomenon was preserved although the oculocephalic reflex was incomplete. There were no other abnormal neurological findings. The brain MRI revealed a high-intensity lesion in left medial midbrain on T2 weighted image. This lesion involved the oculomotor nerve nucleus, the interstitial nucleus of Cajal, and the rostral intersititial nucleus of the medial longitudinal fasciculus (riMLF). We thought that upward gaze palsy of the right eye was resulted from the infarction of the left riMLF or disruption of the axonal collateral of upward gaze fibers in the left oculomotor nucleus. Downward gaze palsy was resulted from the damage of the downward gaze fibers before their decussation, or the damage of the left interstitial nucleus of Cajal. This case provides evidence that unilateral lesion of the midbrain could cause contralateral vertical gaze palsy.     

Neuro-ophthalmology

Eye movement research during the last year is discussed. The review covers the fields of: memory-guided saccades in supplementary motor area lesions, and the vertical saccadic system; cerebral hemispheric localization of smooth pursuit asymmetry; oculomotor disturbances in Wallenberg's syndrome; locomotory gaze instability in vestibular dysfunction; smooth pursuit disorders in vermal infarct; physiologic end-point and rebound nystagmus and the results of surgical and optical treatment of manifest latent nystagmus; clinical/magnetic resonance imaging correlations in abnormalities of horizontal gaze; mesencephalic cholinergic nuclei in progressive supranuclear palsy; as well as mesencephalic damage in diabetic third nerve palsy, divisional oculomotor nerve paresis; and new hypotheses on eye muscle susceptibility in myasthenia gravis.     

Impairment of vertical motion detection and downgaze palsy due to rostral midbrain infarction

Summary We present two cases with acute onset of vertical gaze palsy, mainly consisting of impaired downgaze and apraxia of downward head movements, together with neuropsychological deficits (hypersomnia, impaired attention and disorders of memory and affective control). CT and MRI revealed bilateral post-ischaemic lesions in the dorsomedial thalamus and the mesodiencephalic junction, dorsomedial to the red nucleus, thus being restricted to the territory of the posterior thalamosubthalamic paramedian artery, which includes the region of the rostral interstitial nucleus of the medial longitudinal fascicle as the main premotor nucleus for the generation of vertical saccades. In our patients, oculographic examination with electro-oculography and magnetic search coil recording showed severe impairment of downward more than upward saccades and only minor deficits of vertical pursuit and the vestibulo-ocular reflex. Visual functions were normal, with one exception: a psychophysical test of motion perception revealed a significant deficit in the detection of vertical movements. This could be due to a central adaptive mechanism which, in order to minimize oscillopsia, might elevate thresholds for vertical motion perception in cases of vertical gaze palsy. As an alternative explanation, lesions within the midbrain tegmentum could have damaged subcortical visual pathways involved in motion perception.