Aphasia: A&P/Blood Flow/Etiology

What is the acronym for a stroke?

FAST

• face

• arm

• speech

• time

What are the risk factors of a stroke?

• heart disease

• diabetes (fatty deposits in arteries)

• smoking (makes cell walls thinner)

• obesity (strain on heart)

• birth control pills (lack of blood to brain)

• male

• family history (close family)

• previous stroke

What parts are in the CNS?

Brain

• Brainstem

• Cerebellum

• Diencephalon

• Basal Ganglia

• Cerebral Cortex

• Lobes of the hemisphere

• Broadmann’s Areas

Spinal cord

What is the PNS?

Cranial/spinal nerves that connect the brain with peripheral organs

What is the Autonomic Nervous system?

Controls bodily functions that are not consciously directed

What is the spinal cord?

bundle of nerve fibers within the vertebral column that carry motor impulses to periphery and sensory info to the CNS

• lowest structure in brainste

What are the 3 parts of the brainstem from top to bottom?

Midbrain, Pons, Medulla

What is the medulla?

Controls several autonomic functions

• lowest/most caudal structure in brainstem

• upward extension of spinal cord

What is the pons?

Transmits info related to movement from the cerebrum to the cerebellum, used for hearing/balance

• in middle of brainstem

What is the midbrain?

Controls many sensory and motor functions

• highest structure in brainstem

What are the 2 arteries that wrap around the brainstem?

Basilar and Vertebral

What is a major portion of the hind brain?

Cerebellum

What is the Cerebellum?

• “little brain”

  • 2 hemispheres

  • fissures

  • grey matter = surface, white matter = deep

• back of the brainstem

• part of the motor system

• damage to the system

  • uncoordinate/abnormal voluntary moments

  • dysarthria

What is the Diencephalon?

Includes the Thalamus, Epithalamus, Subthalamus, and Hypothalamus

• located between brainstem and cerebrum

What is the function of the Thalamus?

• integrates sensory info and relays it to the cortical areas

• integrates motor info from basal ganglia and relays it to the cortical areas

• roles in consciousness and alertness

What is the Basal Ganglia?

Modulates movement (sit still/rest)

• deep in the brain near thalamus

What are the impairments of the Basal Ganglia?

• Dykinesias: tremors, involuntary move

• Hypokinesia: restricted range

• Bradykinesia: slowed move

What diseases are associated with the Basal Ganglia?

Parkinson and Huntington Disease

What contains a network of white matter connecting fibers which connect different sections of the brain to each other?

The brain

What are the 3 types of connecting fibers?

• projection fibers

• association fibers

• commissural fibers

What do projection fibers do?

Connect cortex to brainstem

• efferent carries motor commands to body

• afferent carries sensory info back to cortex

What do association fibers do?

Connect different areas of the brain within the same hemisphere

What is fasciculi?

Long association fibers

What are examples of association fibers?

• Superior Longitudinal Fasciculus

  • Arcuate

• Inferior Longitudinal Fasciculus

• Uncinate Fasciculus

What do commissural fibers do?

Connect the 2 hemispheres

• Ex. Corpus Collosum

What happens if there is damage to the Corpus Collosum?

Movement reading and naming problems

What does the cerebral cortex do?

• controls all higher brain functioning

• has 2 hemispheres

• White/grey matter

• Includes: Gyri, Sulci, Fissures

What is a gyri?

Convolutions or hills in the cortex

What is a sulci?

Grooves or valleys in the cortex

What is a fissure?

Deep sulcus

What are the most important fissures and sulci?

• Longitudinal Cerebral Fissure

• Central Sulcus

• Lateral Sulcus/Sylvian Fissure

What does the Longitudinal Cerebral Fissure separate?

left and right hemisphere

What does the Central Sulcus separate?

anterior and posterior halves of the hemisphere

Where is the Lateral Sulcus/Sylvian Fissure located?

Bottom of the frontal lobe and moves up

What are the lobes of the brain? (5)

Frontal, Parietal, Temporal, Occipital, Insula

What are Brodmann’s Areas for?

They associate functions with areas of the brain.

What are the most important structures in the frontal lobe?

• Precentral gyrus/primary motor cortex

  • initiate movement

• Premotor cortex

  • plan movement

• Prefrontal cortex

  • exec function, personality, judgement

• Broca’s area

  • left hemi only, speech/lang production

What makes up the homunculi?

Motor

• primary motor cortex

Sensory

• primary somatosensory area

What is important to note about the size of each area on the homunculi?

The bigger the body part = bigger fine motor control over it

What parts have large fine motor control?

Tongue and pharynx

What parts have large sensory control?

Lips, teeth, gums, jaw, and tongue

What are the most important structures in the parietal lobe?

• Post central gyrus/primary sensory cortex

• *Supramarginal gyrus

• *Angular gyrus

• Somatosensory association cortex

  • integrates sensory info to interpret it

*mark posterior boundaries in left hemi

What are the most important structures in the temporal lobe?

• Heschl’s gyri/primary auditory cortex

  • process auditory info

• Auditory association cortex

  • interpret auditory info

• Wernicke’s Area

  • attaches meaning to what we hear, comprehension

• Superior, Medial, Inferior temporal gyri

What occurs when there is damage to an association?

Agnosia; can’t process sensory info in a specific modality

What are the most important structures in the occipital lobe?

• Primary visual cortex

  • process visual info

• Visual association cortex

  • interpret visual info

What is the role of the insula cortex?

• sensorimotor functions

• limbic system

• gustatory functions

Where is the insula lobe located?

Distal from surface; very deep under front of frontal lobe

What is the Perisylvian Region?

An association cortex important for language in left hemisphere.

What are the fibers surrounding the Perisylvian Region?

Arucate Fasciculus

What are the 3 Tertiary Areas?

• Prefrontal

• Limbic

• Parietal-Occipital-Temporal

What are the disruptions to the cerebral blood supply?

• Lose consciousness after 10 sec

• Electrical activity ceases after 20 sec

• Permanent damage may occur after 4-6 min

What are the two types of cerebral arteries?

External and Internal Carotid Arteries

What are the cerebral arteries attached to the internal carotid?

• Anterior Cerebral

• Middle Cerebral

• Posterior Cerebral

What arteries run along the brain stem?

Vertebral

What makes up the Circle of Willis?

• Anterior communicating

• Anterior cerebral

• Middle cerebral

• Posterior communicating

• Posterior cerebral

• Basilar + Vertebral

What is the Circle of Willis?

A safety feature to keep the redundency of blood flow. Damage to the circle means no blood to the brain. Damage below means blood can still get to the brain through other arteries.

Where does the Carotid Artery System provide blood?

To the Anterior and Middle Cerebral arteries.

Areas:

• majority of lateral surface

• parietal lobe around frontal to posterior temporal

Where does the Vertebral Artery System provide blood?

Posterior Cerebral Arteries

• entire posterior part of brain

What are the 2 watershed areas of the brain?

Anterior and Posterior

What is the posterior watershed?

It’s where middle and posterior arteries overlap to supply blood to the region.

What is the anterior watershed?

It’s where anterior and middle arteries overlap to supply blood to the region.

What are watershed areas?

They receive blood from the small end branches of the primary arteries that supply blood to brain.

What areas of the homunculi are used for speech?

Lateral areas

How do motor pathways work?

Motor info crosses over at the medulla to the opposite side of the body

If aphasia affects left hemisphere, where will it affect on the body?

Right side

What is the visual impairment to be aware of with strokes and why?

Right Neglect

• damage from aphasia can go deep enough to damage right visual field

• can affect therapy

The temporal tract is _____ and the nasal/visual tracts are ______.

ipsilateral; contralateral

The left visual field takes info from what hemisphere?

right hemisphere (contralateral)

What is a stroke?

Sudden onset of a prominent and persistent neurological deficit (medically = cerebrovascular accident - CVA)

What are the stroke symptoms?

• ACUTE = rapid onset

  • weakness of muscles

  • impairment in understanding speech

  • slurred speech

  • blindness/double vision

  • dizziness, impaired balance

  • severe headaches

  • vomiting

• Symptoms lasting at least 24 hrs

What are the types of stroke etiology?

Ischemic, Hemorrhagic, Transient Ischemic Attack (TIA)

What is an Ischemic stroke?

Blockage of blood flow to brain

Thrombotic vs Embolic

• Throm: blood clot forms in artery

• Embo: creates blood clot and blocks blood vessel

What is a Hemorrhagic stroke?

Blood bleeding into brain, involves more pressure

• can cause part of brain to die

• causes: broken blood vessel, aneurysm, A-V malformation

More likely to die, less cell death if you survive

What is a TIA?

Mini stroke

• blockage that breaks free

• symptoms develop quick but go away in less than 24 hrs

• usually 2-3 hrs of symptoms

What are the motor symptoms of stroke?

• Paralysis: loss of voluntary movement

• Paresis: weakness

• Hemiplegia: 1 side paraylsis

• Hemiparesis: 1 side weakness

What are the sensory symptoms of stroke?

• Anesthesia: partial/complete loss of senesation

• Dysesthesia: sensation of pins&needles