Term
| Where do the internal carotids enter the skull? |
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Definition
| through carotid canal of the petrous part of the temporal bone(petrous part of the artery) |
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Term
| What do the cavernous and cerebral parts of the internal carotid form? |
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Definition
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Term
| What branch of the carotid follows the optic nerve? |
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Definition
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Term
| What are the important branches of the carotid? |
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Definition
| Middle cerebral, anterior cerebral, ophthalmic, and lenticulostriate + penetrating arteries |
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Term
| What deficits occur if the anterior cerebral artery is occluded? |
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Definition
| causes restricted contralateral motor and somatosensory deficits usually limited to the distal portions of the lower limb |
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Term
| What happens if the middle cerebral artery is occluded? |
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Definition
| causes major motor and somatosensory deficits (lateral) |
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Term
| What happens if the lenticulostriate + penetrating arteries are damaged? |
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Definition
| internal capsule->damage to a small part of the internal capsule, from rupture or occlusion of a penetrating artery, can cause deficits similar to those resulting from damage to a large expanse of cortex |
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Term
| Where do the cerebral arteries originate? |
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Definition
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Term
| What is the purpose of the vertebral artery siphon? |
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Definition
• dampen pulsations
• allow for lateral flexion of head and neck |
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Term
| What is the path of the vertebral artery and basilar artery? |
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Definition
| • the two vertebral arteries run rostrally alongside the medulla and pons to form the midline basilar artery, which proceeds rostrally along the ventral surface of the pons |
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Term
| Describe the anterior spinal artery. |
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Definition
• each artery joins its mate from the other side, forming a single anterior spinal artery that runs caudally along the ventral midline of the spinal cord, supplying the anterior 2/3 of the cord
• the spinal arteries are reinforced at various points caudal to cervical cord by a more or less continuous series of anastomoses with radicular arteries derived from the thoracic and abdominal aorta
• one particular radicular artery is present at spinal cord level T12 to L2 and is called the great radicular artery (artery or Adamkiewicz) this artery may supply the entire caudal two-thirds of the spinal cord |
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Term
| Describe the posterior spinal artery. |
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Definition
| • each runs caudally along the dorsolateral aspect of the spinal cord and supplies the posterior third of the that half of the cord |
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Term
| What does the posterior inferior cerebellar artery supply? |
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Definition
| inferior surface of the cerebellar hemispheres and sends branches to much of the lateral medulla |
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Term
| What are the major branches of the vertebral arteries? |
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Definition
| anterior spinal arteries,posterior spinal arteries, posterior inferior cerebellar arteries (PICA), medullary branches |
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Term
| What are the branches of the basilar artery? |
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Definition
• anterior inferior cerebellar aa. (AICA)
• superior cerebellar aa.
• pontine
posterior cerebral arteries (PCA) |
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Term
| What does the anterior inferior cerebellar artery supply? |
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Definition
| anterior portions of inferior surface of cerebellum and parts of the caudal pons |
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Term
| Superior cerebellar arteries? |
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Definition
| o supplies the superior surface of the cerebellum and much of the caudal midbrain and rostral pons |
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Term
| What is SAP when pertaining to the cerebellum? |
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Definition
| arterial supply to the cerebellum sometimes called the SAP vessels for Superior cerebellar, Anterior inferior cerebellar and Posterior inferior cerebellar |
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Term
| What is the labyrinthine artery? |
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Definition
| supplies the inner ear – occlusion can lead to vertigo and ipsilateral deafness |
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Term
| What is the function of the posterior cerebral arteries? |
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Definition
medial and inferior portions of temporal lobe
medial aspect of occipital lobe (visual cortex)
also supplies posterior and lateral pars of thalamus and rostral midbrain |
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Term
| What happens if the posterior cerebral artery is occluded? |
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Definition
| occlusion of a posterior cerebral artery at its origin leads to visual field losses in addition to other deficits referable to midbrain and diencephalon |
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Term
| Describe the Circle of Willis. |
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Definition
anastomosis between the two internal carotid arteries and the two vertebral arteries (via the basilar)
posterior communicating artery from each internal carotid joins ipsilateral posterior cerebral artery from the vertebrobasilar systemposterior arc of the circle
anterior communicating artery joins the anterior cerebral arteriesanterior arc of the circle
normal circle is seen in less than 50% of population |
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Term
| What is a transient ischemic attack? |
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Definition
neurological deficits of sudden onset lasting < 24 hrs
usually complete recovery of function seen
etiology
• occluding emboli (most common): internal carotid artery branches most common location
• atherosclerotic stenosis: vertebrobasilar system most common location |
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Term
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Definition
3rd leading cause of death in US
neurological deficit resulting from disturbed regional flow to brain
relatively permanent deficits
etiology
• infarcts (thrombotic or embolic)
• hemorrhages (internal or subarachnoid) |
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Term
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Definition
localized abnormal dilation of arteries supplying the brain
aneurysms of the circle of Willis are the most commonly encountered aneurysms in the body
berry aneurysms: most common type of aneurysm arising from the cerebral arterial circle |
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Term
| What are the symptoms of a MCA occlusion? |
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Definition
• contralateral facial and arm weakness, hemiplegia
• contralateral facial and arm sensory deficits
• homonymous hemianopsia (superior or inferior quadrantopsia if only parietal or temporal lobe affected)
• conjugate deviation of eyes ipsilateral to side of lesion
• language difficulties – Wernicke’s (receptive) aphasia (dominant posterior temporal lobe) or Broca’s (expressive) aphasia if frontal or global aphasia if both areas damaged
• +- apraxia if dominant parietal lobe (ex. dressing apraxia, where patient “forgets” how to dress one limb); or spatial disorganization if non-dominant hemisphere (ex.hemi-neglect syndrome) |
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Term
| What are the signs of a ACA occlusion? |
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Definition
• contralateral leg weakness
• contralateral leg sensory deficits
• behavioral abnormalities (if occlusion is bilateral) consisting of profound apathy, motor inertia and muteness |
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Term
| What are signs of a PCA occlusion? |
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Definition
• contralateral homonymous hemianopsia (occipital lobe)
o macular sparing may be seen
• contralateral hemiplegia (primarily lower limb) due to damage to internal capsule
• ipsilateral 3rd nerve palsy (upper midbrain)
• contralateral sensory loss (thalamus) |
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Term
| What are the signs of a basilar artery occlusion? |
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Definition
• most are catastrophic
• loss of consciousness (reticular activating system (RAS) in medulla)
• quadriplegia with sensory deficits and facial paralysis (pons)
• bilateral ophthalmoplegia and bilateral pupillary abnormalities (midbrain and CN III)
• disordered respiratory patterns and cardiac rates (medulla) |
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Term
| What are the cerebellar signs of a vertebrobasilar occlusion? |
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Definition
• nausea, vomiting, vertigo, ataxia
• occipital HA
• intact motor strength and sensation |
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