Frontal presentation in progressive supranuclear palsy

Rational therapeutic approaches to progressive supranuclear palsy

Progressive supranuclear palsy is a sporadic and progressive neurodegenerative disease, most often presenting as a symmetric, akinetic-rigid syndrome with postural instability, vertical supranuclear gaze palsy and frontal lobe deficits. It belongs to the family of tauopathies and involves both cortical and subcortical structures. Although the exact pathophysiology is not yet fully understood, several lines of evidence point to a crucial contribution from both genetic predisposition and mitochondrial dysfunction. Recently gained insights into the pathophysiology of this disease have led to several hypothesis-driven therapeutic approaches aiming at disease-modification rather than mere symptomatic neurotransmitter-replacement therapy. Agents targeting mitochondrial dysfunction have already shown a positive effect in a phase II study and further studies to verify and expand these results are ongoing. Clinical studies with agents targeting tau dysfunction such as tau-kinase inhibitors, tau-aggregation inhibitors and microtubule stabilizers are in preparation or ongoing. This review presents the current pathophysiological concepts driving these exciting therapeutic developments.

Cerebellar involvement in progressive supranuclear palsy: A clinicopathological study

The clinical heterogeneity of progressive supranuclear palsy (PSP), which is classified as classic Richardson's syndrome (RS) and PSP-Parkinsonism (PSP-P), has been previously discussed. We retrospectively analyzed 22 consecutive Japanese patients with pathologically proven PSP to investigate the clinicopathological heterogeneity. We investigated the clinical features both early in and at any time during the disease course. The pathological severities of neuronal loss with gliosis and tau pathology were also evaluated. On the basis of the clinical features, 10 patients were categorized as having RS, and 8 were categorized as having PSP-P. Four patients presenting with cerebellar ataxia or cerebral cortical signs were categorized as having unclassifiable PSP. Among them, 3 developed cerebellar ataxia as the initial and principal symptom. Notably, tau-positive inclusion bodies in Purkinje cells were significantly more frequently observed in the patients with cerebellar ataxia than in those without cerebellar ataxia. All the patients with cerebellar ataxia exhibited more neuronal loss with gliosis and higher densities of coiled bodies in the cerebellar dentate nucleus than those without cerebellar ataxia. This study confirms the wide spectrum of clinicopathological manifestations associated with PSP regardless of different ethnic origin, and demonstrates that PSP patients manifest cerebellar ataxia.

Emotion recognition in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is an atypical parkinsonian syndrome characterised by akinesis, rigidity, falls, supranuclear gaze palsy and cognitive, particularly executive, dysfunction. This study examined the extent to which emotion recognition is affected by PSP. Although deficits in the recognition of emotion have been reported in several diseases which share clinicopathological characteristics with PSP, it has never been studied systematically in PSP. Twenty-four patients with probable or definite PSP and matched healthy controls were studied using tests of facial identity and facial emotion recognition. Patients were not impaired in recognising famous faces, but they showed significant deficits in the recognition of emotions, particularly negative emotions. Moreover, emotion recognition was strongly correlated with the severity of other cognitive deficits in PSP, but not disease duration. Deficits in emotion recognition form an integral part of the cognitive spectrum of the disease. The findings point to the pathological involvement of key regions necessary for the processing of emotions and to a subtype of PSP with cognitive and emotion recognition impairments. The acknowledgement of deficits in emotion recognition is important for management of both patients and their carers.

Progressive supranuclear palsy: clinicopathological concepts and diagnostic challenges

Progressive supranuclear palsy (PSP) is a clinical syndrome comprising supranuclear palsy, postural instability, and mild dementia. Neuropathologically, PSP is defined by the accumulation of neurofibrillary tangles. Since the first description of PSP in 1963, several distinct clinical syndromes have been described that are associated with PSP; this discovery challenges the traditional clinicopathological definition and complicates diagnosis in the absence of a reliable, disease-specific biomarker. We review the emerging nosology in this field and contrast the clinical and pathological characteristics of the different disease subgroups. These new insights emphasise that the pathological events and processes that lead to the accumulation of phosphorylated tau protein in the brain are best considered as dynamic processes that can develop at different rates, leading to different clinical phenomena. Moreover, for patients for whom the diagnosis is unclear, clinicians must continue to describe accurately the clinical picture of each individual, rather than label them with inaccurate diagnostic categories, such as atypical parkinsonism or PSP mimics. In this way, the development of the clinical features can be informative in assigning less common nosological categories that give clues to the underlying pathology and an understanding of the expected clinical course.

The early neuropsychological and behavioral characteristics of frontotemporal dementia

Frontotemporal lobar degeneration (FTLD) represent a constellation of disorders that may be overlooked or misdiagnosed, despite being fairly common presenile neurodegenerative diseases. Although the cognitive disorder can be difficult to document, particularly early in the dementia course, neuropsychological evaluation can assist in the diagnosis. Neuropsychologists are in an excellent position to draw from related disciplines like personality theory and social psychology to better assess the types of changes that characterize the prodromal and early phases of the disease. This review summarizes the current state of the field in the diagnosis of FTLD and discusses the emerging role of neuropsychology in elucidating the brain organization of complex processes including empathy, behavioral control and inhibition, reward systems, appetitive behaviors, emotional regulation, and goal-orientation. As this review underscores, frontotemporal dementia remains a powerful model for studying brain-behavior relationships.