Posterior inferior cerebellar artery

Intracranial atherosclerotic VA obstruction is mainly located at the origin of the posterior inferior cerebellar artery (PICA) and less frequent at the site of dura penetration. Consequently the most frequent clinical syndrome in VA occlusive disease is the dorsolateral medullary syndrome ( Wallenberg s syndrome) consisting of dizziness, retroorbital pain, facial numbness, dissociated sensory deficit, weakness, hoarseness, dysphagia and vomiting, nystagmus, Horner s syndrome and failure of autonomic respiration (Vuilleumier et al. 1995). 

Amarenco P, Hauw JJ (1990) Cerebellar infarction in the territory of the anterior and inferior cerebellar artery. A clinico-pathological study of 20 cases. Brain 113 139-155 Baquis GD, Pessin MS, Scott RM (1985) Limb shaking - a carotid TIA. Stroke 16 444-448 Barth A, Bogousslavsky J, Regli F (1994) Infarcts in the territory of the lateral branch of the posterior inferior cerebellar artery. J Neurol Neurosurg Psychiatry 57 1073-1076 Baumgartner RW, Sidler C, Mosso M et al (2003) Ischemic lacunar stroke in patients with and without potential mechanism other than small-artery disease. Stroke 34 653-659... 

Vertebral arteries vary in size and symmetry, where mostly the left vertebral artery is the dominant one. The coincidence of vertebral fenestrations and aneurysms is well known. The anterior spinal artery receives tiny vessels from the vertebral arteries which are physiologically not depicted by MRA due to their size. The posterior inferior cerebellar artery (PICA) as the largest, most important and most variable cerebellar artery however, under normal conditions it is constantly depictable with TOF and CE-MRA. 

Medullary infarcts can be medial, lateral or combined (Fig. 14.6). The medial territory is supplied by penetrating vessels from the anterior spinal artery and the distal vertebral artery. The lateral territory main arterial supply comes from penetrating arteries from the distal vertebral artery and the posterior inferior cerebellar artery. The small posterior territory is supplied by the posterior spinal artery and the posterior inferior cerebellar artery. Medial... 

Cerebellar infarcts can be grouped in territorial (superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery and combined), borderzone and lacunar. They are often combined with brain stem infarcts and with superficial posterior cerebral artery or thalamic infarcts. The most common isolated cerebellar infarcts are located in the superior cerebellar artery and posterior inferior cerebellar artery territories (Amarenco 1993 Amarenco et al. 1993,1994). 

Fig. 9 Cerebellar infarct with secondary hydrocephalus and transependymal fluid movement (interstitial edema), (a) Initial diffusion-weighted image with cerebellar infarct in the territory of the left posterior inferior cerebellar artery, (b) Echo-planar T2 axial image shows enlargement of the ventricles prior to surgery for hydrocephalus. Arrow shows transependymal movement of fluid...

The posterior cerebral artery supplies the occipital lobe and portions of the medial and inferior temporal lobe. The arterial supply of the spinal cord is derived from the vertebral arteries and the radicular arteries. The brain is supplied by the internal carotid arteries (the anterior circulation) and the vertebral arteries, which join at the pon tomedullary junction to form the basilar artery (collectively termed the posterior circulation). The brainstem is supplied by the posterior system. The medulla receives blood from branches of the vertebral arteries as well as from the spinal arteries and the posterior inferior cerebellar artery (PICA). The pons is supplied by paramedian and short circumferential branches of the basilar artery. Two major long circumferential branches are the anterior inferior cerebellar artery (AICA) and the superior cerebellar artery. The midbrain receives its arterial supply primarily from the posterior cerebral artery as well as from the basilar artery. The venous drainage of the spinal cord drains directly to the systemic circulation. By contrast, veins draining the cerebral hemispheres and brain stem drain into the dural sinuses. Cerebrospinal fluid also drains into the dural sinuses through unidirectional valves termed arachnoid villi. 

Low flow to the basilar artery can also be caused by vertebral disease. Sometimes one vertebral artery is small and terminates as the posterior inferior cerebellar artery, never making the connection to the basilar artery. Other times, one vertebral artery is occluded. In these two circumstances, flow-limiting disease in the dominant or remaining vertebral artery may then produce... 

The posterior spinal arteries arise from the vertebral or posterior inferior cerebellar arteries and pass as two at each side along the dorsal aspect of the spinal cord. They are sustained to the lower spinal levels by being predominantly fed by the posterior branches of the radicular arteries. The posterior spinal arteries supply the dorsal third of the spinal cord and have a caliber of less than 0.5 mm. 

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