Imagine a zoo with various animal enclosures. Most of the time, you see the animals in their designated areas – lions in the lion exhibit, monkeys in the monkey habitat. But occasionally, you might come across an unexpected sight – a lion roaming around in the monkey enclosure! Similarly, researchers have stumbled upon a peculiar occurrence in the realm of motor neuron disease (MND). While it’s rare, some patients with MND also develop parkinsonian syndromes, such as Parkinson’s disease or progressive supranuclear palsy. The existing studies on this phenomenon have been inconsistent, mostly consisting of individual case reports or small series. To shed light on this curiosity, scientists set out to identify and study patients with both MND and parkinsonian syndromes in a large group. By carefully examining their characteristics and genetic profiles, they hoped to gain a better understanding of this unique combination. Their findings revealed specific patterns within this hybrid condition: some patients displayed typical parkinsonian symptoms like those seen in Parkinson’s disease, while others exhibited atypical manifestations. Additionally, Parkinsonism was more commonly observed in certain subtypes of MND compared to others. These novel insights offer valuable clues for future research into better diagnostic and treatment strategies for individuals dealing with these concurrent conditions. Curious to learn more? Dive into the fascinating details of this study!

BackgroundParkinsonian syndromes may rarely occur in motor neuron disease (MND). However, previous studies are heterogeneous and mostly case reports or small case series. Therefore, we aimed to identify and characterize patients with concurrent parkinsonian syndromes extracted from a cohort of 1,042 consecutive cases diagnosed with MND at a tertiary Italian Center.MethodsDiagnosis of Parkinson’s disease (PD), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) was made according to current criteria. Clinical characterization included: upper and lower motor neuron disease features, typical and atypical parkinsonian features, oculomotor disorders, cognitive testing, MRI features, and, when available molecular neuroimaging. Genetic testing was carried out for major MND and PD-associated genes.ResultsParkinsonian syndromes were diagnosed in 18/1042 (1.7%) of MND patients (7 PD, 6 PSP, 3 CBS, 2 other parkinsonisms). Based on phenotype, patients could be categorized into amyotrophic lateral sclerosis (ALS)-parkinsonism and primary lateral sclerosis (PLS)-parkinsonism clusters. Across the whole database, parkinsonism was significantly more common in PLS than in other MND phenotypes (12.1 vs. 1.1%, p = 5.0 × 10−10). MND patients with parkinsonian features had older age of onset, higher frequency of oculomotor disorders, cognitive impairment, and family history of parkinsonism or dementia. Two patients showed pathogenic mutations in TARDBP and C9orf72 genes.ConclusionSpecific patterns in MND-parkinsonism were observed, with PLS patients often showing atypical parkinsonian syndromes and ALS patients more frequently showing typical PD. Systematic clinical, genetic, and neuropathologic characterization may provide a better understanding of these phenotypes.

Read Full Article (External Site)