进行性核上性麻痹研究新进展

进行性核上性麻痹为神经变性疾病,早期症状不典型,需与帕金森病、橄榄脑桥小脑萎缩、阿尔茨海默病、皮质基底节变性等疾病相鉴别。其临床表现包括垂直性核上性眼肌麻痹、帕金森综合征、轴性肌张力增高、姿势不稳、假性延髓性麻痹以及认知功能障碍等。影像学检查对诊断有重要作用。文中就进行性核上性麻痹的发病机制、临床表现、影像学特点、诊断标准等研究进展予以介绍。     

Progressive Supranuclear Palsy: an Update

Purpose of review

Progressive supranuclear palsy (PSP) is a 4R tau neuropathologic entity. While historically defined by the presence of a vertical supranuclear gaze palsy and falls in the first symptomatic year, clinicopathologic studies identify alternate presenting phenotypes. This article reviews the new PSP diagnostic criteria, diagnostic approaches, and treatment strategies.

Recent findings

The 2017 International Parkinson and Movement Disorder Society PSP criteria outline 14 core clinical features and 4 clinical clues that combine to diagnose one of eight PSP phenotypes with probable, possible, or suggestive certainty. Evidence supports the use of select imaging approaches in the classic PSP-Richardson syndrome phenotype. Recent trials of putative disease-modifying agents showed no benefit.

Summary

The new PSP diagnostic criteria incorporating the range of presenting phenotypes have important implications for diagnosis and research. More work is needed to understand how diagnostic evaluations inform phenotype assessment and identify expected progression. Current treatment is symptomatic, but tau-based therapeutics are in active clinical trials.

     

Familial aggregation in Progressive Supranuclear Palsy and Corticobasal Syndrome

Background: Studies on familial aggregation might be of help to evaluate whether the genetic background has a key role in Progressive Supranuclar Palsy (PSP) and Corticobasal Syndrome (CBS). Only a few studies are available. Objective: To evaluate the prevalence of positive family history (FH) in PSP and CBS in a large sample of patients. Methods: Two hundred and thirty patients and 110 controls entered the study. Patients underwent an extensive clinical, neurological and neuropsychological assessment as well as a structural brain imaging study. A clinical follow‐up further confirmed the diagnosis. Familial aggregation was carefully recorded by a standardised questionnaire. Results: One hundred and twenty‐nine PSP (age at onset = 66.6 ± 7.3, female = 46.1%) and 101 CBS (age at onset = 62.8 ± 8.9, female = 41.6%) were consecutively enrolled. Positive FH was found in 31.8% of PSP (n = 41) and in 31.7% of CBS (n = 32). Familial aggregation was lower in the age‐matched control group compared to patient group (21.8%, P = 0.05). Patients with PSP had higher positive FH for Parkinsonism (63.4%) when compared to FH for dementia (36.6%). In CBS, FH was equally distributed between Parkinsonism (53.1%) and dementia (46.9%). In addition, FH was not associated with age at disease onset in PSP (FH+ versus FH−, 67.0 ± 7.3 vs. 66.7 ± 7.1, P = 0.788) and in CBS (62.6 ± 7.9 vs. 62.9 ± 9.5, P= 0.877). Conclusions: These results argue for familial aggregation in PSP and CBS, further underlying the importance of genetic background in these disorders. Further studies on possible genetic modulators or genetic epistasis contributing to PSP and CBS development are warranted.     

Progressive Supranuclear Palsy in a family with TDP-43 pathology

The discovery of mirror neurons in macaque has led to a resurrection of motor theories of speech perception. Although the majority of lesion and functional imaging studies have associated perception with the temporal lobes, it has also been proposed that the ‘human mirror system’, which prominently includes Broca's area, is the neurophysiological substrate of speech perception. Although numerous studies have demonstrated a tight link between sensory and motor speech processes, few have directly assessed the critical prediction of mirror neuron theories of speech perception, namely that damage to the human mirror system should cause severe deficits in speech perception. The present study measured speech perception abilities of patients with lesions involving motor regions in the left posterior frontal lobe and/or inferior parietal lobule (i.e., the proposed human ‘mirror system’). Performance was at or near ceiling in patients with fronto-parietal lesions. It is only when the lesion encroaches on auditory regions in the temporal lobe that perceptual deficits are evident. This suggests that ‘mirror system’ damage does not disrupt speech perception, but rather that auditory systems are the primary substrate for speech perception.     

Mitochondrial Dysfunction as a Therapeutic Target in Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is a sporadic and progressive neurodegenerative disease, most often leading to a symmetric, akinetic-rigid syndrome with prominent postural instability, vertical supranuclear gaze palsy, and cognitive decline. It belongs to the family of tauopathies and involves both cortical and subcortical structures. There is evidence from laboratory as well as in vivo studies suggesting that mitochondrial energy metabolism is impaired in PSP. Furthermore, several findings suggest that a failure in mitochondrial energy production might act as an upstream event in the chain of pathological events leading to the aggregation of tau and neuronal cell death. Agents targeting mitochondrial dysfunction have already shown a positive effect in a phase II study; however, further studies to verify these results need to be conducted. This review will focus on the pathophysiological concept of mitochondrial dysfunction in PSP and its possible role as a therapeutic target.