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Special interest group

Imaging & Neuroscience

Lead: Mina Langhein, MD · Co-lead: Stuart McAfee, PhD

The Imaging & Neuroscience group studies which brain structures are injured in posterior fossa syndrome (PFS) and how that injury produces its symptoms at a neural network level. We further aim to translate this work into radiological practice: recognizing risk before surgery and injury afterward.

Why we study the injury behind posterior fossa syndrome

Posterior fossa syndrome results from surgery, yet children with similar tumors and operations can have very different outcomes. Knowing exactly which structures are injured, and how that injury disrupts the brain's wider networks, is the foundation for everything else the Society works toward: planning surgery that spares critical pathways, predicting which children are at risk, recognizing injury early on imaging, and designing rehabilitation that targets the right systems.

Pathophysiology research

Which brain structures are injured, the mechanisms that link injury to symptoms, and what basic neuroscience adds.

Explore pathophysiology research

Radiology

What radiologists need to know to recognize risk before surgery and injury afterward, from preoperative MRI to surveillance.

Read the radiology guidance

The cerebellum's brain-wide connections

The cerebellum connects with nearly every part of the brain, so it is no surprise that injury to its output produces a complex mix of speech, motor, emotional, and cognitive symptoms. In children with PFS, changes appear far from the surgical site, from the frontal cortex to the midbrain.1, 2 The group aims to connect these clinical findings with basic neuroscience, including animal models.

Outputs across the brainstem and diencephalon

A systematic review of tracing studies in mammals catalogues direct cerebellar projections to a wide range of brainstem and diencephalic targets, most of which receive input from all three cerebellar nuclei.3 Among them is the periaqueductal gray, a hub for vocalization and for defensive behaviors such as freezing.4, 5

Connections with the neocortex

Mapping across a broad battery of motor, cognitive, social, and affective tasks divides the human cerebellum into functional regions that do not follow its anatomical lobules.6 Each region receives converging input from many areas of the neocortex, to a degree that varies between regions.7

A developing network

Functional brain networks reorganize through childhood from a local to a distributed organization,8 and the cerebellum may play a key role in integrating brain activity from adolescence into adulthood.9 Surgical injury in childhood may therefore disrupt networks that are still maturing.

Animal models

In juvenile rats, splitting the vermis briefly reduced social interaction and vocalization, and bilateral fastigial lesions impaired both for weeks.10, 11 In mice with a severe cerebellar circuit defect, deep brain stimulation of the periaqueductal gray restored social vocalization without improving motor symptoms, suggesting that targeted neuromodulation could one day help restore communication.12

We welcome collaboration with basic scientists studying cerebellar connections, brain network development, or vocal behavior.

Image analysis tools for research

Standard whole-brain methods often misalign the cerebellum, and surgical cavities make postoperative scans harder still. These freely available tools address both problems. The group is also preparing a review of best practices for lesion-symptom mapping in the cerebellum.

SUIT and SUITPy

Infratentorial anatomical templates of the cerebellum and brainstem, with automated isolation and normalization, flatmap visualization, and normalization of focal lesions for lesion-symptom mapping, from the Diedrichsen lab.

Diedrichsen lab: SUIT SUITPy on GitHub

Cerebellar atlas collection

Probabilistic atlases of the cerebellar lobules and deep nuclei, and functional parcellations from task-based and connectivity data.

Diedrichsen lab: Atlases

Brainstem nuclei atlases

Probabilistic atlases of brainstem nuclei in MNI space: the Brainstem Navigator, built from 7 Tesla MRI of living adults and free for non-commercial research, and the Harvard Ascending Arousal Network atlas, in the public domain.

Brainstem Navigator Harvard AAN atlas

Postoperative cerebellar damage detection

Automatic segmentation that accounts for surgical cavities, hemostatic material, and blood products, with normalization that maps surgical damage into atlas space.13

cb_norm_damage on GitHub

Preoperative risk calculator

The GOSH-Colorado-Stanford neural network model, as an online calculator with its source code.14

Open the calculator Code on GitHub

Selected references

  1. Miller NG, Reddick WE, Kocak M, et al. Cerebellocerebral diaschisis is the likely mechanism of postsurgical posterior fossa syndrome in pediatric patients with midline cerebellar tumors. AJNR Am J Neuroradiol. 2010;31(2):288–294. Link
  2. McAfee SS, Robinson G, Gajjar A, et al. Cerebellar mutism is linked to midbrain volatility and desynchronization from speech cortices. Brain. 2023;146(11):4755–4765. Link
  3. Novello M, Bosman LWJ, De Zeeuw CI. A systematic review of direct outputs from the cerebellum to the brainstem and diencephalon in mammals. Cerebellum. 2024;23(1):210–239. Link
  4. Vaaga CE, Brown ST, Raman IM. Cerebellar modulation of synaptic input to freezing-related neurons in the periaqueductal gray. eLife. 2020;9:e54302. Link
  5. Michael V, Goffinet J, Pearson J, et al. Circuit and synaptic organization of forebrain-to-midbrain pathways that promote and suppress vocalization. eLife. 2020;9:e63493. Link
  6. King M, Hernandez-Castillo CR, Poldrack RA, Ivry RB, Diedrichsen J. Functional boundaries in the human cerebellum revealed by a multi-domain task battery. Nat Neurosci. 2019;22(8):1371–1378. Link
  7. King M, Shahshahani L, Ivry RB, Diedrichsen J. A task-general connectivity model reveals variation in convergence of cortical inputs to functional regions of the cerebellum. eLife. 2023;12:e81511. Link
  8. Fair DA, Cohen AL, Power JD, et al. Functional brain networks develop from a “local to distributed” organization. PLoS Comput Biol. 2009;5(5):e1000381. Link
  9. Kundu P, Benson BE, Rosen D, et al. The integration of functional brain activity from adolescence to adulthood. J Neurosci. 2018;38(14):3559–3570. Link
  10. Al-Afif S, Staden M, Krauss JK, Schwabe K, Hermann EJ. Splitting of the cerebellar vermis in juvenile rats: effects on social behavior, vocalization and motor activity. Behav Brain Res. 2013;250:293–298. Link
  11. Al-Afif S, Krauss JK, Helms F, et al. Long-term impairment of social behavior, vocalizations and motor activity induced by bilateral lesions of the fastigial nucleus in juvenile rats. Brain Struct Funct. 2019;224(5):1739–1751. Link
  12. Brandenburg C, Srivastava S, Rey Hipolito AG, Lin T, Arenkiel BR, Sillitoe RV. Frequency-dependent cerebellar circuits independently gate social vocalizations and movement. iScience. 2026;29:117706. Link
  13. Zhang S, McAfee SS, Patay Z, Pinto S, Scoggins MA. Automatic detection and segmentation of postoperative cerebellar damage based on normalization. Neurooncol Adv. 2023;5(1):vdad006. Link
  14. Sidpra J, Marcus AP, Löbel U, et al. Improved prediction of postoperative pediatric cerebellar mutism syndrome using an artificial neural network. Neurooncol Adv. 2022;4(1):vdac003. Link

Get involved

Society members can join this group by contacting its lead or co-lead or writing to info@posteriorfossasociety.org. Not yet a member? Membership is open to clinicians and researchers working on posterior fossa syndrome.

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