Frontal Lobe Divisions

Divisions

1. primary motor cortex

2. premotor cortex

3 prefrontal cortex

-the strip

-activating and controlling motor acts

-a little further forward than primary motor cortex

- complex and skilled movements; fine motor movements

-speech, hand and finger movement

- Exectuive funtioning

-reasoning, abstract thinking, self monitoring, planning, decision making, pragmatic funtion

Functions

- how we know what we are doing within our environment- problem solving

-how we initiate activity in response to our environment

- judgements we make about what occurs in our daily activities

- controls our emotional response

-contros our expressive language

-assignms meaning to words we choose

-involves word associations

-memory for habits and motor activities

Disorders

-Paralysis

-Sequencing

-transcortical Motor Aphasia

-loss of flexibility in thinking

-perseveration

-Attending

-Emotionally Labile

-changes in social behavior and personality

-dificulty w/ problem solving and reasoning

-Broca's Aphasia

sequencing

Transcortical Motor aphasia

perseveration

emotionally labile

-difficulty planning a sequence of cognive or motor steps

-loss of spontaneity in communicating with others

-persistence of a single motor pattern

-dramatic mood changes; cascades of chemicasl and hormones

-aphasia in frontal lobe

-site usually Brodmann area 44

Production

-speech is slow, laborious and halting

- phonetic distortions- perseveration

-agrammatism or telegraphic speech

-dysprosody

-lots of fillers

-relatively good comprehension and reading

- poor repetition

-Writing- often like they talk, slow and laborious, frequent misspellings and letter omissions, often sland down across page rarely write in cursive

Functions

-gross sensation of pain, temperature, touch, etc...

-reading

-naming

-calculations and arithmetic

-cross modal integration of senses- where brain takes diff sources of info and integrates it

Disorders

-Contralateral neglect

-motor apraxia

tactile agnosia

-inability to judge spatial relationships

-Anomia

-Agraphia

-alexia

-dyscalculia

Functions

- visual processing

Disorders

- contralateral visual field neglect

-difficulty with locating objects in the environment

- color agnosia-difficulty with identifying colors

-cortical blindness-confabulate descriptions and scenes

Temporal Lobe

-structures or areas that are specialized for communication

- heschl's gyrus: cortical center for hearing

-Wernicke's area: language comprehension area

- Arcuate Fasciculus: axonal bundle connecting wernicke's area to broca's area- if interrupted you loose ability to repeat

Functions

-hearing ability

-language comprehension

-lexical categorization

-memory encoding

Disorders (? hemisphere)

-hearing/comprehension deficits

-ahasia (lang deficits): comprehension, verbal production, written language, reading, verbal memory or word-finding, repetition

-Dementia: defficits in memory

-sexual dysfunction: lost ability to inhibit

-increased aggression and agitation

Disorders (? hemisphere)

-nonverbal memory

-loss in ability to discriminate tones/musical ability

-deficits in attention

-difficulties with humor and inferences

-pragmatic impairment

Aphasia Production

-fluent

-semantically inappropriate

-paraphasias are common: wrds that are close but instead of saying cat they say tat

-sometimes called "cocktail hour speech": if you are not paying attention to the words it sounds fine but words don't make sense

-Augmentation: complicating a repeated utterance by adding words and paraphasias

-prosody still intact: content of spch snds normal, if ignoring content

-articulation is normal

-empty speech, jargon, logorrrhea or press speech, circumlocution, word finding

-substituting general words without referents for more specific words

e.g. moderate- "I went down to the thing to do the other one and she was only the last one that ever did it."

-strings of neologisms with scattered connected words.

e.g. explaining what the patient hasd for breakfast  "That's frinking the ambivuli binai the frigilator."

-phenomenon characterized by continued talking, with little to no turn taking. Clients often have to be interrupted

-also known as press of speech

-Behavior where patient talks around missing words, knowing the concept but not the word

e.g. discussing what she had for breakfast. "Thismorning for - that meal - the first thing this morning - what I ate - I dined on - chickens, but little - and pig - pork - hen fruit and some bacon, I guess."

Comprehension

-comprehension is usually impaired. In severe cases patients may not understand single words

-language spoken or in visual form: includes their own speech

-may have pure word deafness or blindness

Repetition

-fluent

-grossly restricted retention span

-writing resembles their speech: the letters are well formed and legible, but it often doesn't make sense. Most will use cursive.

-Paraphasia: saying tat instead of cat

- Logorrhea also occurs in their writing

-Anosognosia: patients tend to show a lack of awareness or outward concern about their communication problems

-center section in the brain

- Autonomic functions: food and water intake, body temperature

- hormone and neurotransmitter release

Cerebral spinal fluid flows through ventricles, helps cushion the brain

-ICP:intracranial pressure from buildup in lateral ventricals

obstructive hydrocephelis-a blockage somewhere

non-obstructive hydrocephelis-too much production

-lateral ventricals: good to look for to orient yourself

-3rd and 4th ventricals

anterior pathway

aorta from the heart

common carotid artery

external and internal carotid arteries

circle of willis

posterior pathway

aorta from the heart

subclavian artery

vertebral artery

basilar artery

circle of willis

X-Ray

CT Scan (computerized tomography)

MRI (magnetic resonance imaging)

PET Scan (positron emition temography)

EEG (electroencephalogram)

ERP (evoked related potential)

-structural

-radiation (film)

-2D not very detailed

-gray scale according to detail

-fairly inexpensive

-sometimes used with radio-opaque dyes; e.g. kidney dye test

-structural

-radiation (more like a beam of radiation)

narrow radiation beam generators rotate axially around the patient, radiation detectors instead of film are used to analize the radiation beams, the scanner moves up or down the body in regular steps creating a series of image "slices".

-3D, average detail

permits visualization of soft tissues on available from regular X-Ray

-structural

-no radiation

-3D, high detail

-relatively expensive

-pace-makers and metal objects interfere with scan

-closed and open

-looking at tissue at molecular level and tissue density

-functional: using it to look at where diff. funtions are occurring

-some radiation

-glucose is tagged with a radio-isotope

-3D, average detail

-color-coded

-general idea/picture of what's happening

-measures brain electrical activity; time varying voltages occuring at different frequencies

-functional measure: not good at telling you where something is happening, it is good at telling you when something is happening

-no radiation

-poor spatial resolution, good temporal resolution

-used a lot with seisure disorders

-changes in the electrical activity of the neurons that are temporally associated with physical stimulus or psycological processes

-either negative or positive peaks

-it's hard to pick out an ERP from an EEG so they with average episodes of the same task

neurons

-basic building block of the CNS

-15 billion in the CNS

-three basic sections:

1. dendrites

2. cell body

3. axon

-major chemical messenger that controls voluntary movements

-acetylcholinestrase: breaks down and dissolves Acetylcholine in the synaptic gap

-Myasthenia Gravis: disease characterized by muscle weakness that becomes worse with exercise

-facilitates motor function

-parkinsons's disease: tremor, reduced movement, tysarthria

-some recreational drugs (LSD) cause excessive dopamine release

-EI Dopa

-regulates sleep, emotion, and pain regulation

-95% of serotonin found in the peripheral nervous system

Neurotransmitters

-GABA:glutamate aminobutyric acid

-Peptides (larger molecules)

cell type

-to support and protect the neurons

-40-50 times the number of neurons

four types in CNS

astrocytes

oligodendrocytes

microglia

ependymal cells

Astrocytes

-form supporting network in brain

-form in blood vessel to provide the blood-brain barrier

-form scar tissue around dead brain cells

-scavengers of the CNS

-engulf dead brain tissue and remove it from the lesion site

-contribute to blood-brain barrier

-form lining inside the ventricles where the choroid plexus secrete CSF

(schwann cells-myelinate axons in the PNS)

Thrombosis (insidious process)

Embolism (acute process)

TIA (tranient eschemic attack)

-gradual occlusion of artery, usually by plaque or fatty buildup in areas of slowed blood flow or bifurcation

artery is occluded by a mass flowing in the bloodstream, often a disturbed piece of plaque or fatty buildup

Intracerebral: often in region of brainstem

-Aneurysm:

-elevated blood pressure

-arteriovenous malformation (AVM):

-ballooning or weakness in vessel wall, usually genetically determined

-malformed or tangles mass of arteries and veins, usually genetically determined

Extracerebral: bleeding into the spaces between the meninges, often cause by traumatic brain injury or TBI

-Epidural hematoma:

-subdural hematoma:

-bleeding between the dura mater and the skull

-blleding between the duramater and the arachnoid membrane

TBI

Incidence-any time it happens in a period of time

Prevalence-the number of people who have it in a period of time, not counting anyone twice

-7 million incidents each year in US

-2/3 caused by MVA, most of the rest by falls and assault

males>Female

most commonly occurs with individuals who are 15-25 yrs of age

(not mutually exclusive, somtimes interconnected)

-alcohol and drug abuse

-school adjustment and social history

-socioeconomic status: area in which they live

-personality type: A>B

-previous history of TBI

-participation in sporting events

advocate for safety gear but be careful to not come across as judging. e.g. bicycle helmets

TBI

sports higher vs lower risk

1. boxing

2. motorcycling

3. bicycling

4. rock-climbing

5. horse riding

6. hockey

7. football

TBI

penetrating:

perforates or fractures the skull and penetrates brain tissue

-damage is often focal in nature

-mortality rate is high if in the brainstem area

-however if patient survives initial injury; prognosis for recovery is often surprisingly good

TBI

non penetrating (closed-head): skull stays intact

1. non-acceleration injury:

2. acceleration injury:

1. head is not moving at time of impact

-impression trauma: skull deforms at point of impact: creates kind of negative preasure, pulls tissue away from brain when it impact is over

-elipsoidal: when head is compacted by a slow moving force

2. head undergoes a sudden decreas or increase in motion

-linear accleleration injury: linear path acceleration through center axis: coup/Contre-coup

-angular acceleration injury: off-center acceleration causing a rotation of skull and brain: Diffuse axonal injury (DAI)