Natural history and clinical features of progressive supranuclear palsy: a clinical study

How to spot ocular abnormalities in progressive supranuclear palsy? A practical review

Background

For parkinsonian disorders, progressive supranuclear palsy (PSP) continues to be significant for differential diagnosis. PSP presents a range of ocular abnormalities that have been suggested as optional tools for its early detection, apart from the principal characteristic of postural unsteadiness. Nonetheless, such symptoms may be difficult to identify, particularly during the early onset stage of the disorder. It may also be problematic to recognize these symptoms for general practitioners who lack the required experience or physicians who are not specifically educated and proficient in ophthalmology or neurology.

Main body

Thus, here, a methodical evaluation was carried out to identify seven oculomotor abnormalities occurring in PSP, comprising square wave jerks, the speed and range of saccades (slow saccades and vertical supranuclear gaze palsy), ‘round the houses’ sign, decreased blink rate, blepharospasm, and apraxia of eyelid opening. Inspections were conducted using direct visual observation. An approach to distinguish these signs during a bedside examination was also established. When presenting in a patient with parkinsonism or dementia, the existence of such ocular abnormalities could increase the risk of PSP. For the distinction between PSP and other parkinsonian disorders, these signs hold significant value for physicians.

Conclusion

The authors urge all concerned physicians to check for such abnormalities with the naked eye in patients with parkinsonism. This method has advantages, including ease of application, reduced time-consumption, and requirement of minimal resources. It will also help physicians to conduct efficient diagnoses since many patients with PSP could intially present with ocular symptoms in busy outpatient clinics.

Electronic supplementary material

The online version of this article (10.1186/s40035-019-0160-1) contains supplementary material, which is available to authorized users.

A Review of Treatment Options for Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is an atypical parkinsonian condition characterized by a symmetric akinetic-rigid syndrome, early falls, supranuclear gaze palsy, and a frontotemporal behavioral syndrome. The typical phenotype is termed Richardson's syndrome, but numerous other phenotypes have been described. The pathophysiology of PSP is not fully understood, but dysfunction of the tau protein seems to play a central role. Despite exciting new knowledge on the pathophysiology of PSP, there is still no highly effective symptomatic or disease-modifying treatment. We review the evidence on pharmacotherapy and experimental therapies in PSP and provide levels of recommendation for the off-label use of commonly used drugs in this disorder.

Power calculations and placebo effect for future clinical trials in progressive supranuclear palsy

BACKGROUND

Two recent randomized, placebo-controlled trials of putative disease-modifying agents (davunetide, tideglusib) in progressive supranuclear palsy (PSP) failed to show efficacy, but generated data relevant for future trials.

METHODS

We provide sample size calculations based on data collected in 187 PSP patients assigned to placebo in these trials. A placebo effect was calculated.

RESULTS

The total PSP-Rating Scale required the least number of patients per group (N = 51) to detect a 50% change in the 1-year progression and 39 when including patients with ≤ 5 years disease duration. The Schwab and England Activities of Daily Living required 70 patients per group and was highly correlated with the PSP-Rating Scale. A placebo effect was not detected in these scales.

CONCLUSIONS

We propose the 1-year PSP-Rating Scale score change as the single primary readout in clinical neuroprotective or disease-modifying trials. The Schwab and England Activities of Daily Living could be used as a secondary outcome. © 2016 International Parkinson and Movement Disorder Society.

Challenges Faced by Patients With Progressive Supranuclear Palsy and their Families

The literature is inadequate for understanding the challenges experienced by people with PSP and their families. Therefore, the aim of this study was to understand the challenges of people with PSP and their caregivers and identify their priority need. In this qualitative study, five focus groups were conducted with people with PSP and/or their family caregivers, one group with long-term care staff, and one with community caregivers. Data were analyzed using fundamental qualitative description. Four themes were identified: knowledge, services, research, and symptoms. Knowledge challenges were identified as the priority need, with the most common challenges in this category being lack of knowledge of PSP among community workers, physicians, patients, and family members. Service challenges involved service access and interactions with physicians, community workers, private caregivers, and long-term care staff. Research challenges related to the lack of research and the failure of health care providers or PSP organizations to communicate research findings. Symptoms most often identified as challenging were falls, mobility, vision, mood or thinking, speech, and swallowing. Participants identified their priority need as dissemination of information about PSP. This has not been captured in previous research. This information needs to reach doctors, long-term care staff, community workers, patients, families, and the general public. Subsequent activities to meet this need are summarized. These activities resulted in three new resources: a brochure for patients and families; an information packet for physicians; and a webinar for staff in long-term care and community.

Clinical outcomes of two main variants of progressive supranuclear palsy and multiple system atrophy: a prospective natural history study

Progressive supranuclear palsy (PSP) and parkinsonian subtype of multiple system atrophy (MSA-P) are, after Parkinson's disease (PD), the most common forms of neurodegenerative parkinsonism. Clinical heterogeneity of PSP includes two main variants, Richardson syndrome (PSP-RS) and PSP-parkinsonism (PSP-P). Clinical differentiation between them may be impossible at least during the first 2 years of the disease. Little is known about the differences in natural course of PSP-RS and PSP-P and, therefore, in this study we prospectively followed the clinical outcomes of consecutive, pathologically unconfirmed patients with the clinical diagnoses of PSP-RS (51 patients), PSP-P (21 patients) and MSA-P (49 patients). Estimated mean survival time was 11.2 years for PSP-P, 6.8 years for PSP-RS, and 7.9 years for MSA-P, where a 5-year survival probabilities were 90, 66 and 78 %, respectively. More disabling course of PSP-RS compared to PSP-P was also highlighted through the higher number of milestones reached in the first 3 years of the disease, as well as in the trend to reach all clinical milestones earlier. We found that PSP-P variant had a more favorable course with longer survival, not only when compared to PSP-RS, but also when compared to another form of atypical parkinsonism, MSA-P.

Rate of decline in progressive supranuclear palsy

The rate of patients' decline is critical to properly design trials of disease-modifying agents. We prospectively quantified the progression of 27 progressive supranuclear palsy (PSP) patients for at least 1 year to determine the rate of decline of motor, ocular-motor, neuropsychological, and neuropsychiatric features. PSP patients meeting the National Institute of Neurological Disorders and the Society for Progressive Supranuclear Palsy criteria were assessed using the PSP Rating Scale (PSP-RS) and modified UPDRS. The Mini-Mental State Examination (MMSE) and Frontal Assessment Battery assessed cognitive decline, the Neuropsychiatric Inventory assessed behavior, and the modified Schwab and England scale and UPDRS ADL assessed activities of daily living (ADL). The rate of change of each score was calculated as 1-year worsening score. Power and sample sizes were estimated. PSP patients showed a significant yearly decline in total and subtotal scores of the PSP-RS and UPDRS, as well as in MMSE, and UPDRS and Schwab and England ADL scores. In addition, they had significant deterioration of individual item scores reflecting major aspects of the disease (i.e., ocular-motor). The rate of decline reflected in the UPDRS mirrored that of the PSP-RS. The worsening of the ADL score was positively correlated with the PSP-RS progression of falls and ocular-motor subitem scores and with executive dysfunction. PSP patients showed a significant yearly decline in motor, ocular-motor, and ADL functions. Our findings suggest that using more-advanced technology to measure ocular-motor, postural instability, and ADL will be helpful in planning future therapeutic trials.

Clinical features and disability milestones in multiple system atrophy and progressive supranuclear palsy

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are an adult-onset progressive neurodegenerative disorder that are known to display diverse clinical features and disease progression. We aim to characterize the clinical features and disease progression in patients with MSA and PSP by using a number of relevant disability milestones in Koreans. Forty-one patients with MSA and 14 patients with PSP had been enrolled. The mean age at onset of MSA-C, MSA-P and PSP was 56.7 ± 7.8, 62.5 ± 8.0, 68.9 ± 6.1 years respectively. The most commonly reported symptom at disease onset is disequilibrium/dizziness in MSA-C, tremor in MSA-P and frequent falling in PSP. The mean duration of reaching milestones after disease onset in MSA-C were as followings: 20.8 (urinary incontinence), 22.9 (frequent falling), 27.8 (wheelchair bound), 31.8 (dysarthria) and 35.8 months (diagnosis). The mean duration of reaching milestones after disease onset were 22.0 (urinary incontinence), 32.6 (frequent falling and diagnosis), 41.2 (dysarthria), 61.4 months (wheelchair bound) in MSA-P and 16.8 (dysarthria), 21.6 (diagnosis), 21.7 (frequent falling), 24.0 months (wheel chair bound) in PSP. In the case of MSA, dizziness may occur for the first time. Thus, when the patient complains of non-specific dizziness, a follow-up examination to distinguish it from MSA can be helpful. There was a trend for patients with MSA-C to reach more disability milestones than in MSA-P and PSP before diagnosis. It may explain why patients with MSA-C are required more detail history taking and neurologic examination at an earlier stage.

PSP as distinguished from CBD, MSA-P and PD by clinical and imaging differences at an early stage

OBJECTIVE

Because it is often difficult to precisely diagnose and distinguish progressive supranuclear palsy (PSP) from corticobasal degeneration (CBD), multiple system atrophy-parkinsonism (MSA-P) and Parkinson's disease (PD) at the onset of the disease, we compared the patients and clarified the features of these diseases.

METHODS

We compared 77 PSP, 26 CBD, 26 MSA-P and 166 PD patients from clinical and imaging points of view including cerebral blood flow (CBF) in the frontal eye field.

RESULTS

The clinical characteristics of PSP were supranuclear gaze disturbance, optokinetic nystagmus (OKN) impairment and falls at the first visit. On head MRI, midbrain tegmentum atrophy was much more frequently detected in PSP than in all of the other groups. Heart-to-mediastinum average count ratio (H/M) in iodine-123 meta-iodobenzyl guanidine ((123)I-MIBG) myocardial scintigraphy was not decreased in PSP, CBD, MSA-P and PD-Yahr 1 (-1), but patients of PD-2, 3, 4 and 5 showed a significant decrease compared with the PSP group. The CBF in the left frontal eye field of PD-3 group and that in right frontal eye field of PD-3 and PD-4 groups were lower than that of PSP group, although other groups showed a tendency without a significant decrease compared with PSP group.

CONCLUSION

PSP is distinguishable from CBD, MSA-P and PD even at the early stage with extra-ocular movement (EOM) disturbance, falls, atrophy of the midbrain tegmentum, and H/M in (123)I-MIBG myocardial scintigraphy, and the reduction of CBF in area 8 could serve as a supplemental diagnostic method for distinguishing PSP from PD-3 or PD-4.

Detection of baseline and near-fall postural stability

It is unknown whether there are any measurable warning signs just before a patient falls. This study of postural position just prior to a fall involved a subject standing on a balance beam while wearing a gyroscope-based wireless data acquisition system. Results show a variation in postural position when the subject appeared stable. This occurred well before the subject experienced a fall and could not be classified as pre-fall or fall. The results show that there are two distinguishable levels of postural stability - baseline and near-fall.

Current and future treatments in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is an atypical parkinsonian disorder that, in spite of its growing recognition, is still underdiagnosed. For management, prognosis, and research, an accurate and early diagnosis is essential. PSP is a relentlessly progressive neurodegenerative disorder, clinically characterized by parkinsonism with prominent axial involvement and postural instability, bulbar symptoms, supranuclear ophthalmoplegia, and executive dysfunction. Abnormal neuronal and glial four-repeat tau aggregations affecting the basal ganglia and selective brainstem structures result in dysfunction of the five frontosubcortical circuits and brainstem functions. Primary therapeutic approaches are based on neurotransmitter replacement and palliative strategies. This article reviews the experience and challenges with neurotransmitter replacement and palliative strategies through an extensive literature search of studies published between 1965 and 2005. The role of and limited experience with alternative therapies, such as deep brain stimulation and pallidotomy, are also discussed. Advances in the development of biological therapies for PSP and a better understanding of its etiopathogenesis will likely result from epidemiologic studies and developed four-repeat tau-transgenic animal models. The management of patients with this disorder poses a considerable challenge and includes symptomatic and palliative strategies, as well as education and support, to improve the quality of life for patients and their caregivers.

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.