Clinical Case A patient delays initiation of movement, displays an uneven trajectory in moving her hand from above her head to touch her nose, and is uneven in her attempts to demonstrate rapid alternation of pronating and supernating movements of the hand and forearm. Which regions of the brain is most likely contains the lesion?

Clinical Case A 55-year-old male had been complaining about his having difficulty in coordinating the use of his arms in meaningful ways. For example, when examined by a neurologist, the patient was unable to move his finger accurately to his nose from his side when requested to do so but instead he would undershoot or overshoot the target. He also had difficulty in making Rapid alternating rotational movements of the hand. The neurologist believed that the patient was suffering from a disorder that resulted in a lesion of a region of the cerebellum or structures related to it. Which regions of the cerebellum is most likely contained this lesion

Cerebellum External features located in posterior cranial fossa. 2. Communicate with brain stem by cerebellar peduncles. Superior cerebellar peduncles( Brachium conjunctiva) Middle cerebellar peduncles (Brachium pontis) Inferior cerebellar peduncle (Restiform Body

Crebellum External features cont.. Anatomical sub divisions of Cerebellum Longitudinal division Vermis, Paravermal Region, Hemisphere Transverse division Anterior Lobe ---- primary fissure Posterior Lobe ----posterolateral fissure Flocculonodular Lobe

Cerebellum Classification Archicerebellum (Equilibrium, Tone & Posture of trunk Muscles) Paleocerebllum (Tone & Posture of limb Muscles) Neocerebellum (Smooth performance of skilled act by coordination of move) Classification by its Connections Vestibulocerebellum Spinocerebellum cerebrocerebellum

Crebellum External features cont.. Subdivision of Flocculonodular Lobe Nodulus Flocculus Subdivision of Anterior Lobe Vermis Hemisphere Lingula Central Lobule Ala Central Lobule postcentral fissure Culmen Quadrangular Lobule

Crebellum External features cont.. Subdivision of Posterior Lobe Vermis crebellar Hemisphere Declive Simple Lobule postcentral fissure Folium Superior Semilunar Lobule horizontal fissure Inferior Semilunar Lobule Tuber Gracile Lobule prepyramidal fissure Pyramid Biventer Lobule secondary fissure Uvula Tonsil

Crebellum Internal features cont.. Cerebellar Cortex Molecular Layer Purkinje Cell Layer Granular Layer Deep Cerebellar Nuclei Fastigial Nuclei (Nucleus Interpositus) Emboliform Nucleus Globose Nucleus Dentate Nucleus

Crebellum Internal features cont.. Cerebellar Cortex I. Molecular Layer Stellate Cell (inhibitory) afferent: parallel fiber efferent: Purkinje cell dendrite Basket Cell ---- GABA (inhibitory) efferent: Purkinje cell soma Parallel Fiber granule cell axon Purkinje Cell Dendrite

Cerebellum Internal features cont.. II. Purkinje Cell Layer Purkinje Cell -- 15,000,000 in number -- GABA (inhibitory) afferent: parallel fiber climbing fiber stellate cell basket cell efferent: deep cerebellar nuclei nuclei

Cerebellum Internal features cont.. III. Granular Layer Granular Cell -- 50,000,000,000 in number -- glutamic acid (excitatory) afferent: mossy fiber efferent: Purkinje cell dendrite basket cell, stellate cell Golgi cell Golgi Cell -- GABA (inhibitory) afferent: parallel fiber, mossy fiber rosette efferent: granule cell dendrite

Cerebellum Internal features cont.. Synaptic Glomerulus Afferent terminals on granular layer  Mossy Fiber Rosette -- afferent fibers except inferior olivary input -- 2/3 of medullary center  Granular Cell Dendrite -- main afferent input  Golgi Cell Axon -- synapse on granule cell dendrite -- GABA (inhibitory) - Surrounded by Astrocyte Foot Process

Cerebellum Connections 1. Inferior Cerebellar Peduncle Restiform Body Posterior Spinocerebellar Tract Olivocerebellar tract Cuneocerebellar Tract Reticulocerebellar Tract Juxtarestiform Body Vestibulocerebellar Tract Primary Vestyibular Fiber

Cerebellum Connections Afferent Connections (2): 2. Middle Cerebellar Peduncle Pontocerebellar fiber Corticopontocerebellar Fiber Reticulocerebellar Fiber 3. Superior Cerebellar Peduncle Anterior Spinocerebellar Tract Cerulocerebellar fiber Raphecerebellar fiber Rubrocerebellar fiber Hypothalamocerebellar fiber

Cerebellum Connections Efferent Connections:   1. Superior Cerebellar Peduncle   Cerebellothalamic fiber - From 3 deep nuclei to VPLo, VLc, CL Cerebellorubral fiber - From nucleus globusus And dentate nucleus 2. Inferior Cerebellar Peduncle   Fastigiovestibular fiber Descending portion of Uncinate fasciculus

Cerebellar Pathway

Main Connections of the Vestibulocerebellum Vestibular Organ Floculonodular Lobe Vermis VESTIBULAR NUCLEUS vestibulospinal tract MLF FASTIGIAL NUCLEUS lower motor neuron ARCHICEREBELLUM LMN

Main Connections of the Paleocerebellum RED NUCLEUS NUCLEUS INTERPOSITUS rubrospinal tract Inferior Olivry Nucleus ANTERIOR LOBE PARAVERMAL ZONE lower motor neuron PALEOCEREBELLUM SPINAL CORD spinocerebellar tract

Main Connections of the Neocerebellum CEREBRAL CORTEX THALAMUS DENTATE NUCLEUS pyramidal tract Pontine Nucleus POSTERIOR LOBE CEREBELLAR HEMISPHERE lower motor neuron NEOCEREBELLUM LMN

Pyramidal Tract and Associated Circuits upper motor neuron UMN Cerebellum BASAL GANGLIA pyramidal tract lower motor neuron UMN

Cerebellum and Automatic Motor Control Lower Motor Neuron (LMN) Motor Cortex CEREBELLUM Red Nucleus Vestibular Nucleus Reticular Formation Lower Motor Neuron (LMN) Proprioceptors

Functions Of Cerebellum  Maintenance of Equilibrium - balance, posture, eye movement  Coordination of automatic movement of walking and posture maintenance - posture, gait  Adjustment of Muscle Tone  Motor Leaning – Motor Skills  Cognitive Function

Cerebellum Disorders Ataxia: incoordination of movement - decomposition of movement - dysmetria, past-pointing - dysdiadochokinesia(Adidydakokinesia) - rebound phenomenon of Holmes - gait ataxia, truncal ataxia, titubation Intention Tremor Hypotonia, Nystagmus

Cerebellum Disorders Archicerebellar Lesion: medulloblastoma Paleocerebellar Lesion: gait disturbance Neocerebellar Lesion: hypotonia, ataxia, tremor