Blood supply via internal carotid system
Includes ACA and MCA
Tonic gaze deviation towards lesion
Global aphasia, dysgraphia, dyslexia, dyscalculia, disorientation (dominant lesion)
Spatial or visual neglect (non-dominant lesion)
Signs and Symptoms:
Contralateral sensory and motor symptoms in the lower extremity (sparing hands/face)
Urinary and bowel incontinence
Left sided lesion: akinetic mutism, transcortical motor aphasia
Right sided lesion: Confusion, motor hemineglect
Presence of primitive grasp and suck reflexes
May manifest gait apraxia
Signs and Symptoms:
Hemiparesis, facial plegia, sensory loss contralateral to affected cortex
Motor deficits found more commonly in face and upper extremity than lower extremity
Dominant hemisphere involved: aphasia
Wernicke's aphasia (receptive aphasia) -> patient unable to process sensory input and don't understand verbal communication
Broca's aphasia (expressive aphasia) -> patient unable to communicate verbally, even though understanding may be intact
Nondominant hemisphere involved: dysarthria (motor deficit of the mouth and speech muscles; understanding intact) w/o aphasia, inattention and neglect side opposite to infarct
Contralateral homonymous hemianopsia
Gaze preference toward side of infarct
Agnosia (inability to recognize previously known subjects)
Wernicke's aphasia (receptive aphasia) -> patient unable to process sensory input and don't understand verbal communication
Broca's aphasia (expressive aphasia) -> patient unable to communicate verbally, even though understanding may be intact
Blood supply via the vertebral artery
Branches include, AICA, Basilar artery, PCA and PICA
Signs and Symptoms:
Crossed neuro deficits (i.e., ipsilateral CN deficits w/ contralateral motor weakness)
Multiple, simultaneous complaints are the rule (including loss of consciousness, nausea/vomiting, alexia, visual agnosia)
5 Ds: Dizziness (Vertigo), Dysarthria, Dystaxia, Diplopia, Dysphagia
Isolated events are not attributable to vertebral occlusive disease (e.g. isolated lightheadedness, vertigo, transient ALOC, drop attacks)
Approximately 25% associated with aortic dissection
Signs and Symptoms:
Quadriplegia, coma, locked-in syndrome
"Crossed signs" in which a patient has unilateral cranial nerve deficits but contralateral hemiparesis and hemisensory loss suggest brainstem infarction
Millard-Gubler syndrome (ventral pontine syndrome) -- ipsilateral CN VI and VII palsy with contralateral hemiplegia of extremities
Sparing of vertical eye movements (CN III exits brainstem just above lesion)
Thus, may also have miosis b/l
One and a half syndrome (seen in a variety of brainstem infarctions)
"Half" - INO (internuclear ophthalmoplegia) in one direction
"One" - inability for conjugate gaze in other direction
Convergence and vertical EOM intact
Medial inferior pontine syndrome (paramedian basilar artery branch)
Ipsilateral conjugate gaze towards lesion (PPRF), nystagmus (CN VIII), ataxia, diplopia on lateral gaze (CN VI)
Contralateral face/arm/leg paralysis and decreased proprioception
Medial midpontine syndrome (paramedian midbasilar artery branch)
Ipsilateral ataxia
Contralateral face/arm/leg paralysis and decreased proprioception
Medial superior pontine syndrome (paramedian upper basilar artery branches)
Ipsilateral ataxia, INO, myoclonus of pharynx/vocal cords/face
Contralateral face/arm/leg paralysis and decreased proprioception
Millard-Gubler syndrome (ventral pontine syndrome) -- ipsilateral CN VI and VII palsy with contralateral hemiplegia of extremities
Thus, may also have miosis b/l
"Half" - INO (internuclear ophthalmoplegia) in one direction
"One" - inability for conjugate gaze in other direction
Convergence and vertical EOM intact
Ipsilateral conjugate gaze towards lesion (PPRF), nystagmus (CN VIII), ataxia, diplopia on lateral gaze (CN VI)
Contralateral face/arm/leg paralysis and decreased proprioception
Ipsilateral ataxia
Contralateral face/arm/leg paralysis and decreased proprioception
Ipsilateral ataxia, INO, myoclonus of pharynx/vocal cords/face
Contralateral face/arm/leg paralysis and decreased proprioception
~2% of all cerebral infarctions
May present with nonspecific symptoms - nausea/vomiting, dizziness, ataxia, nystagmus (more commonly horizontal)
Lateral superior pontine syndrome
Ipsilateral ataxia, nausea/vomiting, nystagmus, Horner syndrome, conjugate gaze paresis
Contralateral loss of pain/temperature in face/extremities/trunk, and loss of proprioception/vibration in LE > UE
Ipsilateral ataxia, nausea/vomiting, nystagmus, Horner syndrome, conjugate gaze paresis
Contralateral loss of pain/temperature in face/extremities/trunk, and loss of proprioception/vibration in LE > UE
Signs and Symptoms:
Common after CPR, as occipital cortex is a watershed area
Unilateral headache (most common presenting complaint)
Visual field defects (contralateral homonymous hemianopsia, unilateral blindness)
Visual agnosia - can't recognize objects
Possible macular sparing if MCA unaffected
Motor function is typically minimally affected
Lateral midbrain syndrome (penetrating arteries from PCA)
Ipsilateral CN III - eye down and out, pupil dilated
Contralateral hemiataxia, tremor, hyperkinesis (red nucleus)
Medial midbrain syndrome (upper basilar and proximal PCA)
Ipsilateral CN III - eye down and out, pupil dilated
Contralateral paralysis of face, arm, leg (corticospinal)
Ipsilateral CN III - eye down and out, pupil dilated
Contralateral hemiataxia, tremor, hyperkinesis (red nucleus)
Ipsilateral CN III - eye down and out, pupil dilated
Contralateral paralysis of face, arm, leg (corticospinal)
Lateral inferior pontine syndrome
Ipsilateral facial paralysis, loss of corneal reflex (CN VII)
Ipsilateral loss of pain/temperature (CN V)
Nystagmus, nausea/vomiting, vertigo, ipsilateral hearing loss (CN VIII)
Ipsilateral limb and gait ataxia
Ipsilateral Horner syndrome
Contralateral loss of pain/temperature in trunk and extremities (lateral spinothalamic)
Signs and Symptoms:
Lateral medullary/Wallenberg syndrome
Ipsilateral cerebellar signs, ipsilateral loss of pain/temperature of face, ipsilateral Horner syndrome, ipsilateral dysphagia and hoarseness, dysarthria, vertigo/nystagmus
Contralateral loss of pain/temp over body
Also caused by vertebral artery occlusion (most cases)
May present with either lacunar c/l pure motor or c/l pure sensory (of face and body)
Pure c/l motor - posterior limb of internal capsule infarct
Pure c/l sensory - thalamic infarct (Dejerine and Roussy syndrome)
C/l motor plus sensory if large enough
Clinically to cortical large ACA + MCA<unk>  - the following signs suggest cortical rather than internal capsule:
Gaze preference
Visual field defects
Aphasia (dominant lesion, MCA)
Spatial neglect (non-dominant lesion)
Others
Ipsilateral ataxic hemiparesis, with legs worse than arms - posterior limb of internal capsule infarct
Dysarthria/Clumsy Hand Syndrome - basilar pons or anterior limb of internal capsule infarct
Pure c/l motor - posterior limb of internal capsule infarct
Pure c/l sensory - thalamic infarct (Dejerine and Roussy syndrome)
Gaze preference
Visual field defects
Aphasia (dominant lesion, MCA)
Spatial neglect (non-dominant lesion)
Ipsilateral ataxic hemiparesis, with legs worse than arms - posterior limb of internal capsule infarct
Dysarthria/Clumsy Hand Syndrome - basilar pons or anterior limb of internal capsule infarct
Medial medullary syndrome - displays alternating pattern of sidedness of symptoms below
Contralateral arm/leg weakness and proprioception/vibration
Tongue deviation towards lesion
ASA syndrome
Watershed area of hypoperfusion in T4-T8
Bilateral pain/temp loss in trunk and extremities (spinothalamic)
Bilateral weakness in trunk and extremities (corticospinal)
Preservation of dorsal columns
Ischemic stroke
Stroke
Hemorrhagic stroke
Seizures/postictal paralysis 
Subarachnoid hemorrhage
Syncope
Vertebral and carotid artery dissection
Subdural hemorrhage