Neuroanatomical Mechanism of Cerebellar Mutism After Stroke

Area of Science:

• Neuroscience
• Neurology
• Neuroimaging

Background:

• Cerebellar mutism (CM) is a rare neurological condition typically seen in children, characterized by a lack of speech following cerebellar lesions.
• While often associated with surgical interventions, CM can also arise from spontaneous events like cerebellar hemorrhage.

Purpose of the Study:

• To describe a rare case of cerebellar mutism (CM) occurring after a spontaneous cerebellar hemorrhage.
• To investigate the potential neuroanatomical mechanisms underlying CM in this specific case using advanced neuroimaging techniques.

Main Methods:

• Case report of a patient experiencing CM following spontaneous cerebellar hemorrhage.
• Clinical assessment including evaluation of speech, movement, and oropharyngeal function.
• Advanced neuroimaging including Diffusion Tensor Imaging (DTI) and Tracts Constrained by UnderLying Anatomy (TRACULA) analysis.
• Reconstruction and qualitative analysis of cerebello-frontal pathways using FMRIB Software Library (FSL).

Main Results:

• The patient presented with mutism, irritability, reduced spontaneous movements, and oropharyngeal apraxia.
• DTI revealed significant volume reduction in medial frontal projection fibers of the corpus callosum.
• TRACULA analysis failed to visualize forceps major and minor and bilateral cingulum-angular bundles.
• Reconstructed cerebello-frontal pathways showed fiber continuity but a reduced number of fibers.

Conclusions:

• Cerebello-frontal pathway disconnection is suggested as a potential neuroanatomical mechanism contributing to cerebellar mutism (CM).
• Damage to the brain network connecting the occipital lobe, cingulate gyrus, and cerebellum due to hemorrhage may also play a role in CM pathogenesis.