Category: Parkinsonism, Atypical: MSA
Objective: To determine pyramidal signs in multiple system atrophy (MSA) and the associations with other clinical characteristics.
Background: The clinical manifestations of MSA are comprised with symptoms of four domains: autonomic, parkinsonism, cerebellar, and pyramidal systems. However, the involvement of pyramidal system, manifesting as upper motor neuron (UMN) symptoms and signs, are frequent yet insufficiently studied in MSA.
Method: We reviewed 40 autopsy-confirmed MSA cases from New York Brain Bank and assessed the pyramidal signs using UMN burden scores (0-36, calculated by scoring deep tendon reflexes, muscle tone, and corticospinal tract signs). Based on UMN burden scores, MSA patients were divided into those with high UMN burden (HUMN) ≥ 18 and low UMN < 18 (LUMN). We compared the clinical characteristics of MSA cases with HUMN vs. LUMN using Chi-Square and independent t-test. We investigated if UMN burden is associated with the presence of autonomic, parkinsonism, and cerebellar features. We conducted a multivariable linear regression to examine if UMN burden is associated with survival. We investigated whether cases with more severe glial cytoplasmic inclusion deposition (GCI score ≥ 2, Figure 1B and 1C) in the motor cortex have higher UMN burden scores compared to less severe cases (GCI score < 2, Figure 1A).
Results: MSA cases with HUMN (35%, n = 14) and those with LUMN (65%, n = 26) have similar age, sex, age of onset, and disease duration. MSA cases with HUMN are more likely to be MSA-P than those with LUMN (p = 0.016). MSA patients with HUMN are more likely to have urinary incontinence (OR = 4.00, p = 0.046), but less likely to have orthostatic hypotension (OR = 0.24, p = 0.043) and erectile dysfunction (OR = 0.03, p = 0.006). The HUMN cases do not differ from LUMN in regards to bowel dysfunction, stridor, and dry eyes. Patients with HUMN and those with LUMN are not different in survival. Cases with more severe GCI deposition (GCI ≥ 2), compared to the less severe group (GCI < 2), has higher UNN burden (43.7 ± 16.8 vs. 29.0 ± 20.2, p = 0.039).
Conclusion: Pyramidal signs are associated with different MSA subtypes and autonomic features. Further studies are needed to fully characterize this often-neglected clinical domain for MSA.
To cite this abstract in AMA style:
C. Lin, A. Viswanathan, T. Chen, P. Faust, S. Kuo. The Implications of Pyramidal Signs in Multiple System Atrophy [abstract]. Mov Disord. 2021; 36 (suppl 1). https://www.mdsabstracts.org/abstract/the-implications-of-pyramidal-signs-in-multiple-system-atrophy/. Accessed June 15, 2025.« Back to MDS Virtual Congress 2021
MDS Abstracts - https://www.mdsabstracts.org/abstract/the-implications-of-pyramidal-signs-in-multiple-system-atrophy/