<P> The cerebellum is provided with blood from three paired major arteries: the superior cerebellar artery (SCA), the anterior inferior cerebellar artery (AICA), and the posterior inferior cerebellar artery (PICA). The SCA supplies the upper region of the cerebellum . It divides at the upper surface and branches into the pia mater where the branches anastomose with those of the anterior and posterior inferior cerebellar arteries . The AICA supplies the front part of the undersurface of the cerebellum . The PICA arrives at the undersurface, where it divides into a medial branch and a lateral branch . The medial branch continues backward to the cerebellar notch between the two hemispheres of the cerebellum; while the lateral branch supplies the under surface of the cerebellum, as far as its lateral border, where it anastomoses with the AICA and the SCA . </P> <P> Damage to the cerebellum often causes motor - related symptoms, the details of which depend on the part of the cerebellum involved and how it is damaged . Damage to the flocculonodular lobe may show up as a loss of equilibrium and in particular an altered, irregular walking gait, with a wide stance caused by difficulty in balancing . Damage to the lateral zone typically causes problems in skilled voluntary and planned movements which can cause errors in the force, direction, speed and amplitude of movements . Other manifestations include hypotonia (decreased muscle tone), dysarthria (problems with speech articulation), dysmetria (problems judging distances or ranges of movement), dysdiadochokinesia (inability to perform rapid alternating movements such as walking), impaired check reflex or rebound phenomenon, and intention tremor (involuntary movement caused by alternating contractions of opposing muscle groups). Damage to the midline portion may disrupt whole - body movements, whereas damage localized more laterally is more likely to disrupt fine movements of the hands or limbs . Damage to the upper part of the cerebellum tends to cause gait impairments and other problems with leg coordination; damage to the lower part is more likely to cause uncoordinated or poorly aimed movements of the arms and hands, as well as difficulties in speed . This complex of motor symptoms is called ataxia . </P> <P> To identify cerebellar problems, neurological examination includes assessment of gait (a broad - based gait being indicative of ataxia), finger - pointing tests and assessment of posture . If cerebellar dysfunction is indicated, a magnetic resonance imaging scan can be used to obtain a detailed picture of any structural alterations that may exist . </P> <P> The list of medical problems that can produce cerebellar damage is long, including stroke, hemorrhage, swelling of the brain (cerebral edema), tumors, alcoholism, physical trauma such as gunshot wounds or explosives, and chronic degenerative conditions such as olivopontocerebellar atrophy . Some forms of migraine headache may also produce temporary dysfunction of the cerebellum, of variable severity . Infection can result in cerebellar damage in such conditions as the prion diseases and Miller Fisher syndrome, a variant of Guillain--Barré syndrome . </P>

Most brain areas control functioning on the ipsilateral side of the body