Skip to content
Inciteful Med

MSA-P vs. MSA-C: Understanding Your Subtype and Scans

Last updated:

Multiple System Atrophy (MSA) has two main subtypes: MSA-P causes Parkinson-like stiffness and tremors, while MSA-C causes balance and coordination issues. Neurologists use MRI, DAT, and PET scans to look for hallmark signs, like the 'hot cross bun' or 'putaminal rim', to confirm your subtype.

Key Takeaways

  • • MSA-P primarily mimics Parkinson's disease with stiffness and tremors, while MSA-C mainly affects balance, coordination, and speech.
  • • An MRI can show specific visual clues to identify your subtype, such as the 'hot cross bun' sign for MSA-C or the 'putaminal rim' sign for MSA-P.
  • • Specialized scans like DAT and FDG-PET help evaluate brain function, dopamine loss, and glucose metabolism to confirm an MSA diagnosis.
  • • Non-motor symptoms can vary by subtype, with pain being significantly more common in individuals with MSA-P.

While Multiple System Atrophy (MSA) is a single disease, it typically presents in one of two ways. These “subtypes” are defined by which part of the brain is most affected and which symptoms are most prominent [1]. Understanding your subtype can help you and your care team better predict which symptoms may need the most attention [2].

Note: You do not need to memorize the complex medical terms in this section. They are simply the clues your neurologist uses to understand your specific condition and tailor your care.

The Two Main Subtypes

The subtypes are named based on their primary symptoms:

  • MSA-P (Parkinsonian type): This is the most common form in Europe and North America [3]. It primarily mimics Parkinson’s disease, causing stiffness, slowness of movement (bradykinesia), and tremors [4]. Biologically, this type is associated with striatonigral degeneration (SND), which is the loss of nerve cells in the area of the brain that produces dopamine [4][5].
  • MSA-C (Cerebellar type): This is the more common form in Asian countries like Japan [3]. It primarily affects balance, coordination, and speech—a condition known as ataxia [4]. Biologically, it is linked to olivopontocerebellar atrophy (OPCA), which is the shrinking of the cerebellum and brainstem [4][1].

What Brain Scans Can Show

Imaging is a vital tool for confirming a diagnosis of MSA and distinguishing between the subtypes.

MRI Findings

MRI (Magnetic Resonance Imaging) uses powerful magnets to create a detailed picture of brain structure. Specialists look for specific “hallmarks”:

  • The “Hot Cross Bun” Sign: This is a classic indicator of MSA-C [6]. It appears as a white, cross-shaped pattern in the pons (part of the brainstem) on certain MRI views, caused by the loss of specific nerve fibers [7][8].
  • The “Putaminal Rim” Sign: More common in MSA-P, this appears as a bright, thin line along the outer edge of the putamen (a brain structure involved in movement) [9].
  • Atrophy: Scans can also show visible shrinking (atrophy) in the cerebellum (for MSA-C) or the putamen (for MSA-P) [10][11].

Specialized Scans (DAT and PET)

Other scans look at how the brain functions rather than just how it looks:

  • DAT Scan: This tracks dopamine transporters in the brain. While both Parkinson’s and MSA show a loss of dopamine, MSA-P typically shows a more severe and rapid loss than Parkinson’s [12][13].
  • FDG-PET Scan: This scan measures how the brain uses glucose (sugar) for energy [14]. It can help confirm a subtype by showing reduced activity in the putamen (for MSA-P) or the cerebellum (for MSA-C) [14].
  • Functional MRI (fMRI): This can identify “disconnections” in brain networks, such as a breakdown in the communication between the cerebellum and the rest of the brain in MSA-C [15].

Clinical Differences Between Subtypes

The subtypes also vary in terms of non-motor symptoms. For instance, pain is significantly more common in MSA-P (affecting about 76% of patients) than in MSA-C (45%) [16]. Additionally, some research suggests that MSA-C may progress slightly faster in terms of mobility, though every patient’s experience is unique [17]. It is also possible for a person to start with symptoms of one subtype and develop features of the other as the disease progresses [18].

Frequently Asked Questions

What is the difference between MSA-P and MSA-C?
MSA-P primarily causes Parkinson-like symptoms such as stiffness, slowness, and tremors. MSA-C mostly affects balance, coordination, and speech, which is known as ataxia.
What does the 'hot cross bun' sign on my MRI mean?
The 'hot cross bun' sign is a classic indicator of the MSA-C subtype. It appears as a white, cross-shaped pattern in the brainstem on an MRI, caused by the loss of specific nerve fibers.
What is the 'putaminal rim' sign?
The 'putaminal rim' sign is a bright, thin line seen on an MRI along the outer edge of the putamen in the brain. It is more commonly found in patients with the MSA-P subtype.
Can a DAT scan tell the difference between Parkinson's disease and MSA?
Yes, while both conditions show a loss of dopamine, a DAT scan in someone with MSA-P typically shows a more severe and rapid loss of dopamine transporters than in Parkinson's disease.
Is pain a common symptom of Multiple System Atrophy?
Pain is a frequent non-motor symptom, particularly in the MSA-P subtype. It affects approximately three-quarters of patients with MSA-P, compared to slightly less than half of those with MSA-C.

Questions for Your Doctor

  • • Based on my symptoms and scans, do I have the MSA-P or MSA-C subtype?
  • • Did my MRI show the 'hot cross bun sign' or the 'putaminal rim sign'?
  • • How do these specific imaging findings confirm my diagnosis and rule out Parkinson's disease?
  • • What does the 'striatonigral degeneration' or 'olivopontocerebellar atrophy' mentioned in my reports mean for my daily mobility?
  • • Since I have MSA-P, am I more likely to experience certain non-motor symptoms like pain or bladder issues?
  • • Should we consider a DAT scan or FDG-PET scan to get a clearer picture of my brain's dopamine levels or metabolism?

Questions for You

  • • Do I find it harder to stay balanced while walking (ataxia), or do I feel more 'stuck' and stiff (parkinsonism)?
  • • Have I noticed any specific tremors, like a fine shaking when I hold my hands out in front of me?
  • • How quickly did I go from noticing my first symptom to needing help with walking or daily tasks?

Want personalized information?

Type your question below to get evidence-based answers tailored to your situation.

References

  1. 1

    An update on the cerebellar subtype of multiple system atrophy.

    Ciolli L, Krismer F, Nicoletti F, Wenning GK

    Cerebellum & ataxias 2014; (1()):14 doi:10.1186/s40673-014-0014-7.

    PMID: 26331038
  2. 2

    The characteristic of nonmotor symptoms with different phenotypes and onsets in multiple system atrophy patients.

    Zhang J, Han J, Shi Z, et al.

    Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia 2023; (109()):1-5 doi:10.1016/j.jocn.2022.12.012.

    PMID: 36634471
  3. 3

    Multiple system atrophy: clinicopathological characteristics in Japanese patients.

    Ozawa T, Onodera O

    Proceedings of the Japan Academy. Series B, Physical and biological sciences 2017; (93(5)):251-258 doi:10.2183/pjab.93.016.

    PMID: 28496050
  4. 4

    Recent advances in neuropathology, biomarkers and therapeutic approach of multiple system atrophy.

    Koga S, Dickson DW

    Journal of neurology, neurosurgery, and psychiatry 2018; (89(2)):175-184 doi:10.1136/jnnp-2017-315813.

    PMID: 28860330
  5. 5

    Multiple system atrophy - a clinicopathological update.

    Jellinger KA

    Free neuropathology 2020; (1()):17 doi:10.17879/freeneuropathology-2020-2813.

    PMID: 37283673
  6. 6

    Imaging Markers of Multiple System Atrophy and Their Association With Disease Severity: A Cross-Sectional Study.

    Dash SK, Kamble N, Stezin A, et al.

    Cureus 2024; (16(8)):e67896 doi:10.7759/cureus.67896.

    PMID: 39328619
  7. 7

    A challenging case presentation of multiple system atrophy cerebellar type: A rare case report from Somalia.

    Sidow NO, Ibrahim AA, Ibrahim IG, et al.

    Radiology case reports 2024; (19(12)):6183-6186 doi:10.1016/j.radcr.2024.08.145.

    PMID: 39376957
  8. 8

    Rapidly Progressive Multiple System Atrophy-Cerebellar Type in a 52-Year-Old Woman: Diagnostic Challenges in a Resource-Limited Setting.

    Singh KV, Nimmagadda SP, Panda A, et al.

    Clinical case reports 2025; (13(12)):e71529 doi:10.1002/ccr3.71529.

    PMID: 41306404
  9. 9

    18 F-FDG PET/MRI in Multiple System Atrophy-Parkinsonian Type (MSA-P).

    Mashriqi F, di Rocco A, Franceschi AM

    Clinical nuclear medicine 2025; (50(7)):641-643 doi:10.1097/RLU.0000000000005708.

    PMID: 40241432
  10. 10

    Voxel-Based Meta-Analysis of Gray Matter Abnormalities in Multiple System Atrophy.

    Lin J, Xu X, Hou Y, et al.

    Frontiers in aging neuroscience 2020; (12()):591666 doi:10.3389/fnagi.2020.591666.

    PMID: 33328969
  11. 11

    Morphometric MRI profiles of multiple system atrophy variants and implications for differential diagnosis.

    Krismer F, Seppi K, Göbel G, et al.

    Movement disorders : official journal of the Movement Disorder Society 2019; (34(7)):1041-1048 doi:10.1002/mds.27669.

    PMID: 30919495
  12. 12

    Patterns of dopamine transporter imaging in subtypes of multiple system atrophy.

    Bu LL, Liu FT, Jiang CF, et al.

    Acta neurologica Scandinavica 2018; (138(2)):170-176 doi:10.1111/ane.12932.

    PMID: 29573392
  13. 13

    Longitudinal Change of DAT SPECT in Parkinson's Disease and Multiple System Atrophy.

    Sakakibara S, Hashimoto R, Katayama T, et al.

    Journal of Parkinson's disease 2020; (10(1)):123-130 doi:10.3233/JPD-191710.

    PMID: 31707374
  14. 14

    [The clinical application value of brain 18F-FDG PET/CT in the diagnostics of Parkinsonian syndromes].

    Gu Q, Chen SF, Chen KL, et al.

    Zhonghua yi xue za zhi 2023; (103(41)):3294-3300 doi:10.3760/cma.j.cn112137-20230707-01181.

    PMID: 37926574
  15. 15

    Functional MRI in Multiple System Atrophy: A Promising Biomarker for Clinical Applications.

    Xiao S, Ding Y, Weiss A, et al.

    Neuropsychiatric disease and treatment 2026; (22()):566720 doi:10.2147/NDT.S566720.

    PMID: 41738058
  16. 16

    Pain in Multiple System Atrophy a Systematic Review and Meta-Analysis.

    Campese N, Caliò B, Leys F, et al.

    Movement disorders clinical practice 2023; (10(12)):1738-1749 doi:10.1002/mdc3.13897.

    PMID: 38094640
  17. 17

    Rapid Progression and Shorter Survival in Indians Affected with Probable MSA: A Prospective Cohort Study.

    Rukmani MR, Yadav R, Bhaskarapillai B, et al.

    Movement disorders clinical practice 2025; (12(12)):2113-2127 doi:10.1002/mdc3.70301.

    PMID: 40853512
  18. 18

    Multiple system atrophy in Hokkaido, Japan: a prospective registry study of natural history and symptom assessment scales followed for 5 years.

    Matsushima M, Yabe I, Sakushima K, et al.

    BMJ open 2021; (11(2)):e045100 doi:10.1136/bmjopen-2020-045100.

    PMID: 33558361

This page explains Multiple System Atrophy subtypes and imaging results for educational purposes. Your neurologist and radiologist are the best sources for interpreting your specific brain scans and diagnosis.

Stay up to date

Get notified when new research about Multiple system atrophy is published.

No spam. Unsubscribe anytime.