Lesion-Symptom Mapping of the Human Cerebellum

Background Post-stroke cognitive impairment can occur after damage to various brain regions, and cognitive deficits depend on infarct location. The Mini-Mental State Examination (MMSE) is still widely used to assess post-stroke cognition, but it has been criticized for capturing only certain cognitive deficits. Along these lines, it might be hypothesized that cognitive deficits as measured with the MMSE primarily involve certain infarct locations. Aims This comprehensive lesion-symptom mapping study aimed to determine which acute infarct locations are associated with post-stroke cognitive impairment on the MMSE. Methods We examined associations between impairment on the MMSE (<5th percentile; normative data) and infarct location in 1198 patients (age 67 ± 12 years, 43% female) with acute ischemic stroke using voxel-based lesion-symptom mapping. As a frame of reference, infarct patterns associated with impairments in individual cognitive domains were determined, based on a more detailed neuropsychological assessment. Results Impairment on the MMSE was present in 420 patients (35%). Large voxel clusters in the left middle cerebral artery territory and thalamus were significantly (p < 0.01) associated with cognitive impairment on the MMSE, with highest odds ratios (>15) in the thalamus and superior temporal gyrus. In comparison, domain-specific impairments were related to various infarct patterns across both hemispheres including the left medial temporal lobe (verbal memory) and right parietal lobe (visuospatial functioning). Conclusions Our findings indicate that post-stroke cognitive impairment on the MMSE primarily relates to infarct locations in the left middle cerebral artery territory. The MMSE is apparently less sensitive to cognitive deficits that specifically relate to other locations.

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Mapping of long-term cognitive and motor deficits in pediatric cerebellar brain tumor survivors into a cerebellar white matter atlas

Child s Nervous System ◽

10.1007/s00381-021-05244-2 ◽

2021 ◽

Author(s):

Frederik Grosse ◽

Stefan Mark Rueckriegel ◽

Ulrich-Wilhelm Thomale ◽

Pablo Hernáiz Driever

Keyword(s):

Brain Tumor ◽

Executive Function ◽

Cognitive Function ◽

White Matter ◽

Cerebellar Nuclei ◽

Motor Deficits ◽

Deep Cerebellar Nuclei ◽

Cerebellar White Matter ◽

Lesion Symptom Mapping

Abstract Purpose Diaschisis of cerebrocerebellar loops contributes to cognitive and motor deficits in pediatric cerebellar brain tumor survivors. We used a cerebellar white matter atlas and hypothesized that lesion symptom mapping may reveal the critical lesions of cerebellar tracts. Methods We examined 31 long-term survivors of pediatric posterior fossa tumors (13 pilocytic astrocytoma, 18 medulloblastoma). Patients underwent neuronal imaging, examination for ataxia, fine motor and cognitive function, planning abilities, and executive function. Individual consolidated cerebellar lesions were drawn manually onto patients’ individual MRI and normalized into Montreal Neurologic Institute (MNI) space for further analysis with voxel-based lesion symptom mapping. Results Lesion symptom mapping linked deficits of motor function to the superior cerebellar peduncle (SCP), deep cerebellar nuclei (interposed nucleus (IN), fastigial nucleus (FN), ventromedial dentate nucleus (DN)), and inferior vermis (VIIIa, VIIIb, IX, X). Statistical maps of deficits of intelligence and executive function mapped with minor variations to the same cerebellar structures. Conclusion We identified lesions to the SCP next to deep cerebellar nuclei as critical for limiting both motor and cognitive function in pediatric cerebellar tumor survivors. Future strategies safeguarding motor and cognitive function will have to identify patients preoperatively at risk for damage to these critical structures and adapt multimodal therapeutic options accordingly.

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SURG-40. SURGICAL RESECTIONS IN BROCA’S AREA DO NOT LEAD TO BROCA’S APHASIA

Neuro-Oncology ◽

10.1093/neuonc/noaa215.886 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii212-ii212

Author(s):

John Andrews ◽

Nathan Cahn ◽

Benjamin Speidel ◽

Valerie Lu ◽

Mitchel Berger ◽

...

Keyword(s):

Inferior Frontal Gyrus ◽

Brain Surgery ◽

Broca’S Area ◽

Broca's Area ◽

Supramarginal Gyrus ◽

Broca's Aphasia ◽

Broca’S Aphasia ◽

Language Evaluations ◽

Lesion Symptom Mapping ◽

Normal Speech

Abstract Brodmann’s areas 44/45 of the inferior frontal gyrus (IFG), are the seat of Broca’s area. The Western Aphasia Battery is a commonly used language battery that diagnoses aphasias based on fluency, comprehension, naming and repetition. Broca’s aphasia is defined as low fluency (0-4/10), retained comprehension (4-10/10), and variable deficits in repetition (0-7.9/10) and naming (0-8/10). The purpose of this study was to find anatomic areas associated with Broca’s aphasia. Patients who underwent resective brain surgery in the dominant hemisphere were evaluated with standardized language batteries pre-op, POD 2, and 1-month post-op. The resection cavities were outlined to construct 3D-volumes of interest. These were aligned using an affine transformation to MNI brain space. A voxel-based lesion-symptom mapping (VLSM) algorithm determined areas associated with Broca’s aphasia when incorporated into a resection. Post-op MRIs were reviewed blindly and percent involvement of pars orbitalis, triangularis and opercularis was recorded. 287 patients had pre-op and POD 2 language evaluations and 178 had 1 month post-op language evaluation. 82/287 patients had IFG involvement in resections. Only 5/82 IFG resections led to Broca’s aphasia. 11/16 patients with Broca’s aphasia at POD 2 had no involvement of IFG in resection. 35% of IFG resections were associated with non-specific dysnomia and 36% were normal. By one-month, 76% of patients had normal speech. 80% of patients with Broca’s aphasia at POD 2 improved to normal speech at 1-month, with 20% improved to non-specific dysnomia. The most highly correlated (P< 0.005) anatomic areas with Broca’s aphasia were juxta-sylvian pre- and post-central gyrus extending to supramarginal gyrus. While Broca’s area resections were rarely associated with Broca’s aphasia, juxta-sylvian pre- and post-central gyri extending to the supramarginal gyrus were statistically associated with Broca’s type aphasia when resected. These results have implications for planning resective brain surgery in these presumed eloquent brain areas.

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Multi-atlas based segmentation of human cerebellum

2020 17th International Multi-Conference on Systems, Signals & Devices (SSD) ◽

10.1109/ssd49366.2020.9364095 ◽

2020 ◽

Author(s):

Asma Daly ◽

Hedi Yazid ◽

Basel Solaiman ◽

Najoua Essoukri Ben Amara

Keyword(s):

Human Cerebellum

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