SQSTM1 Pro392Leu presenting as a corticobasal syndrome with progressive nonfluent aphasia.

Corticobasal syndrome is generally considered to be a sporadic condition. There are familial and isolated genetic cases, associated with GRN, MAPT, c9orf72 or PNRP variants. Some reports implicate other genes: LRRK2, CHMP2B, GBA, CYP27A1, PSEN1, APP, TARDBP and TBK1. Here, we report a case of a patient carrying a SQSTM1 Pro392Leu variant. We report a 57-year-old right-handed-woman with a history of progressive speech impairment, marked right side rigidity and bradykinesia, with rest tremor and stimulus sensitive myoclonus. She had predominantly right-sided apraxia. She had right side agraphestesia and astereognosis. MRI showed asymmetrical left frontotemporoparietal atrophy. DaTSCAN showed predominantly left involvement, PiB-PET was negative. CSF NfL was of 9356.5pg/mL. She carried a heterozygous variant P392L in SQSTM1. This case report expands the spectrum of phenotypes associated with SQSTM1 pathogenic variants. It also expands the list of genes associated with corticobasal syndrome, supporting the involvement of the ubiquitin-proteasome system in this condition.

Nucleus Basalis of Meynert Degeneration Predicts Cognitive Decline in Corticobasal Syndrome.

BACKGROUND: Cognitive changes are common in corticobasal syndrome (CBS) and significantly impact quality of life and caregiver burden. However, relatively few studies have investigated the neural substrates of cognitive changes in CBS, and reliable predictors of cognitive impairment are currently lacking. The nucleus basalis of Meynert (NbM), which serves as the primary source of cortical cholinergic innervation, has been functionally associated with cognition. This study aimed to explore whether patients with CBS exhibit reduced NbM volumes compared with healthy control participants and whether NbM degeneration can serve as a predictor of cognitive impairment in patients with CBS. METHODS: In this study, we investigated in vivo volumetric changes of the NbM in 38 patients with CBS and 84 healthy control participants. Next, we assessed whether gray matter degeneration of the NbM evaluated at baseline could predict cognitive impairment during a 12-month follow-up period in patients with CBS. All volumetric analyses were performed using 3T T1-weighted images obtained from the 4-Repeat Tauopathy Neuroimaging Initiative. RESULTS: Patients with CBS displayed significantly lower NbM volumes than control participants (p < .001). Structural damage of the NbM also predicted the development of cognitive impairment in patients with CBS as assessed by longitudinal measurements of the Clinical Dementia Rating Sum of Boxes (p < .001) and Mini-Mental State Examination (p = .035). CONCLUSIONS: Our findings suggest that NbM atrophy may represent a promising noninvasive in vivo marker of cognitive decline in CBS and provide new insights into the neural mechanisms that underlie cognitive impairment in CBS.

Corticobasal degeneration with visual hallucination as an initial symptom: A case report.

Although the initial symptoms of corticobasal degeneration (CBD) are varied, psychiatric symptoms are uncommon. Here, we report the autopsy findings of a patient with early CBD who presented with hallucinations. A 68-year-old man developed memory loss and visions of bears and insects. Because of slow vertical eye movement, postural instability, and levodopa-unresponsive parkinsonism, the patient initially was clinically diagnosed with progressive supranuclear palsy. He died of a urinary tract infection 11 months after the onset of the disease. Histopathological examination revealed neuronal loss and gliosis, which were severe in the substantia nigra and moderate in the globus pallidus and subthalamic nucleus. Astrocytic plaques were scattered throughout the amygdala and premotor cortex. The superficial cortical layers lacked ballooned neurons and spongiosis, and tau deposition was greater in glia than in neurons. The amygdala contained a moderate number of argyrophilic grains and pretangles. Western blot analysis showed a 37-kDa band among the low-molecular-weight tau fragments. Because the CBD pathology was mild, we attributed the patient's visual hallucinations to the marked argyrophilic grain pathology. CBD can occur with psychiatric symptoms, including visual hallucinations, and argyrophilic grain pathology may be associated with psychiatric symptoms.

FDG-PET patterns associated with ideomotor apraxia and imitation apraxia in patients with corticobasal syndrome.

INTRODUCTION: Apraxia is a core clinical feature of corticobasal syndrome (CBS). Among the subtypes of apraxia, ideomotor and imitation apraxia are frequently found in CBS. However, little is known about the brain networks that are characteristic of each apraxia subtype or their clinical implication. In this study, we used 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to explore the specific patterns of glucose hypometabolism that are characteristic of apraxia subtypes by focusing on ideomotor and imitation apraxia. METHODS: We compared the areas of glucose hypometabolism in the brains of 52 patients with CBS and 13 healthy controls, both as a whole and according to apraxia subtypes. In addition, we investigated the relationship between the apraxia subtypes and the clinical phenotype of CBS. RESULTS: In patients with CBS, common hypometabolism was observed in the frontal gyrus, precentral gyrus and caudate regardless of apraxia subtypes. In particular, ideomotor apraxia was associated with hypometabolism in the angular gyrus, while imitation apraxia was associated with hypometabolism in the posterior part including the postcentral gyrus, precuneus, and posterior cingulate gyrus. Patients who showed both ideomotor and imitation apraxia were more likely to show the typical features of CBS and progressive supranuclear palsy compared with patients showing only one type of apraxia. CONCLUSION: Group comparison analysis using FDG-PET revealed distinct pathways of ideomotor and imitation apraxia in CBS. These findings add to our understanding of the brain networks underlying apraxia in association with the clinical features of CBS.

Pain in neurodegenerative diseases with atypical parkinsonism: a systematic review on prevalence, clinical presentation, and findings from experimental studies.

Parkinson's disease-related pain has increasingly been investigated in research studies. Still, only a few studies have addressed the prevalence and clinical characteristics of pain in neurodegenerative disorders with atypical parkinsonism. The existing evidence, although scarce, suggests that, similarly as in Parkinson's disease, individuals with neurodegenerative diseases with atypical parkinsonism might be predisposed to the development of persistent pain. Today, as the global population is aging and we face an epidemic of neurodegenerative disorders, under-treated pain is taking a great toll on an ever-rising number of people. Here, we provide an up-to-date review of the current knowledge on the prevalence of pain, its clinical features, and findings from experimental studies that might signpost altered pain processing in the most prevalent neurodegenerative disorders with atypical parkinsonism: multiple system atrophy, progressive supranuclear palsy, corticobasal syndrome, frontotemporal dementia, and dementia with Lewy bodies. Finally, we point out the current gaps and unmet needs that future research studies should focus on. Large-scale, high-quality clinical trials, coupled with pre-clinical research, are urgently needed to reveal the exact pathophysiological mechanisms underpinning heightened pain and pave the path for mechanistically-driven analgesic interventions to be developed, ultimately leading to an improvement in the quality of life of individuals with neurodegenerative disorders.