Since it receives projections from the pons through the corticopontocerebellar pathway, it is also termed the pontocerebellum. The neocerebellum consists of most of the cerebellar hemispheres. It plays a role in controlling muscle tone and axial and limb movements. It is also known as the spinocerebellum because it receives input primarily from the spinal cord. The paleocerebellum consists of mainly the vermis of the anterior lobe. As a result of these connections, the archicerebellum controls body equilibrium and eye movements. It also receives input from areas concerned with eye movements. It is otherwise called the vestibulocerebellum because it has several connections with the vestibular nucleus. The archicerebellum corresponds to the flocculonodular lobe. From an embryogenetic and functional standpoint, the cerebellum can be divided intoįig -2 Schematic diagram of cerebellum showing lobes and lobules. The posterolateral fissure separates the posterior lobe from the flocullonodular lobes. The primary fissure divides it into anterior and posterior lobes. It has two fissures which divide it into three lobes. It has a midline portion, the vermis, and two lateral portions, the cerebellar hemispheres. It is separated from the occipital lobes by the tentorium cerebelli. It lies dorsal to the pons and medulla oblongata. The cerebellum is located in the posterior fossa. Localise from symptomatology of the patient, which part of the cerebellum is involved.įig -1 Midsagittal section of the cerebellum.The symptoms produced by lesions of the cerebellum.The cerebellar anatomy and connections of the cerebellum.At the end of the episode, we will understand We will learn the approach to a patient with cerebellar ataxia. We will focus on cerebellar ataxia in this session. Both vestibular and sensory ataxia won’t have other features of cerebellar ataxia like dysarthria, tremor etc. Patients with vestibular ataxia often have vertigo. A patient with sensory ataxia will have sensory symptoms like paresthesia, and ataxia will be more on closing eyes, usually described as a washbasin sign. The movements err in speed, range, force and timing. Cerebellar ataxia results from defective timing of the sequential contraction of the agonist and antagonist. The cerebellum acts as the orchestra’s conductor and finely coordinate the gross movements done by the pyramidal system. One of the major cerebellar functions is the automatic excitation of the antagonist muscles at the end of a movement, with the simultaneous inhibition of agonist muscles that initiated the movement. The cerebellum regulates muscle tone, posture, and equilibrium. A cerebellar pathology usually causes ataxia, but it can be caused by defects in proprioception and vestibular function. Ataxia is defined as a lack of voluntary coordination of muscle activity. An ataxia case is often kept for final year medical school clinical examination. Ataxia is a common symptom with which a patient presents to a neurologist.
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