Cranial Nerve VII:

General Info

• Facial Nerve
• Mixed motor and sensory
• Enters/exits at lower border of pons
• Travels through internal auditory meatus with CN VIII

Cranial Nerve VII:

Motor

• muscles of facial expression
• some fibers -> stimulate tears, saliva, mucous membranes

Cranial Nerve VII:

Sensory

• Taste
• anterior 2/3 of tongue

Cranial Nerve VII:

Corticobulbar tracts

1. Lower half innervation

2. upper half innervation

1. contralateral innervation
2. bilateral innervation

Cranial Nerve VII:

Unilateral Cortical/UMN damage

• contralateral facial droop on opposite side
• Lower face only!!

Cranial Nerve VII:

Unilateral nerve/LMN damage

• Ipsilateral facial droop affecting entire face

CN VIII:

General Info

• Auditory-Vestibular
• Mixed (motor and sensory)
• Enters brainstem in upper medulla
• auditory/vestibular nuclei

CN VIII:

Auditory path

• superior olivary nucleus
• inferior colliculus,
• Medial Geniculate Body
• Temporal Lobe

CN VIII:

Vestibular path

• Cerebellum
• midbrain
• reticular formation
• spinal cord

• Brainstem to cortex
• cochlear nuclei
• superior olivary complex
• lateral lemniscus (tract)
• inferior colliculus
• Medial geniculate body
• Heschel's gyrus

CN IX:

General Info

• Mixed motor and sensory
• Enters/exits at medulla

CN IX:

Motor

• stylopharyngeus
• elevates pharynx
• stimulate salivary glands

CN IX:

Sensory

• sensory from mucosa of pharynx, tonsils, Eustacian tube, tonge
• Taste from posterior 1/3 of tongue

CN X:

General Info

• Vagus
• Mixed motor and sensory (90% motor)
• Enters/exits at medulla

CN X:

 Motor

• Laryngeal/pharyngeal muscles
• parasympathetic innervation of cardiac muscles, smooth muscles of trachea/bronchi, stomach/intestines

CN X:

Sensory

• sensory info from
• muscles of pharynx
• epiglottis
• trachea/bronchi
• esophagus/stomach
• taste from pharynx

CN X:

3 branches

1. Pharyngeal branch
2. Superior laryngeal branch
3. Recurrent laryngeal branch

CN X:

Pharyngeal branch

• Motor
• velum
• pharynx
• damage
• hypernasality
• dysphagia
• nasal regurgitation

CN X:

Superior laryngeal nerve

• Internal laryngeal nerve
• sensory only
• epiglottis, larynx above vocal folds
• External laryngeal nerve
• motor only
• cricothyroid
• SLN damage
• reduced pitch control
• risk of aspiration due to reduced sensation

CN X:

Recurrent laryngeal nerve

• motor
• intrinsic laryngeal muscles
• sensory
• vocal folds and below
• damage
• vocal fold paralysis
• breathy/hoarse voice, diplophonia
• risk of aspiration

CN XI:

General Info

• Spinal Accessory
• Motor only
• Leaves brainstem at medulla

CN XI:

Motor

• mixes with Vagus to innervate velum, uvula and instrinsic laryngeal muscles
• Trapezius and sternocleidomastoid

CN XII:

General Info & 

Damage to nerve

• Hypogloassal
• Motor
• Leaves brainstem at lower medulla
• innervations all intrinsic and most extrinsic tongue muscles
• damage -> weakness of tongue muscles

Function Areas: Lobes

Frontal

• pre-frontal
• execultive function, personality
• Posterior frontal
• motor planning and execution
• Inferior/posterior frontal
• language and speech (primarily left hemisphere)

Function Areas: Lobes

Parietal

• anterior: post-central gyrus
• primary sensory area
• association areas
• Inferior parietal
• association areas
• integrate vision, language comprehension

Function Areas: Lobes

Temporal

• Superior/posterior
• Heschel's gyrus - primary auditory
• Wernicke's area (left only)
• language comprehesion
• Medial (deep)
• Hippocampus
• memory

Function Areas: Lobes

Occipital

• visual processing
• object recognition (what) = ventral pathway
• occipital -> temporal
• Spatial recognition (where) = dorsal pathway
• occipital -> parietal
• Shape, color, form, location processing = seperate areas

Left/Right Dichotomies

(Generalizations):

Left

• Analytic
• Linear
• Sequential, temporal
• Language
• Auditory processing

Left/Right Dichotomies

(Generalizations):

Right

• Holistic (gestalt)
• Nonlinear
• Parallel
• Music
• Visual spatial processing

Language Processing:

Language Networks

• Comprehension and production
• Syntax and semantics

Language Processing:

Syntax

• left lateralized
• temporal-inferior frontal

Language Processing:

Semantics

• primarily left, but also right
• temporo-frontal network

Language Processing:

Prosody

• right hemisphere network
• temporo-frontal network

• Broadman's areas
• BA 44 - Broca's area
• BA 41-42 - Wernicke's area
• BA 39-40 Angular and supramarginal gyri

LH Language Pathways:

Dorsal pathway 1

• Posterior STG to cortex
• Auditory-motor integration

LH Language Pathways:

Dorsal pathway 2

• STG to BA 45

LH Language Pathways:

Ventral pathways 1 & 2

• STG to frontal operculum and BA 45
• Sound-to-meaning mapping

Bilingual Brain:

Multiple language learning

• Easiest before age 5
• minimal confusion between languages

Bilingual Brain:

Benefits

• Improves attention and working memory
• inhibiting distractors
• Delays onset of dementia/Alzheimer's disease
• Cognitive reserve

Bilingual Brain:

Brain function

• Language stored together in left hemisphere
• increased neuronal density in left inferior parietal cortex
• Right dorsolateral pre-frontal cortex activity
• Aids in attention/working memory efficiency
• active during "bilingual mode"
• Rapid switching between languages

Bilingual Brain:

Aphasia in Bilingual adults

• Can affect either/both languages
• treatment - can be done in either/both languages
• Considerations for treatments
• Earliest learned?
• Most commonly used?
• Most fluent?
• Gains may transfer to untreated language

• Aphasia
• Anterior lesion (~Broca's area)
• broca's aphasia; non-fluent aphasia
• primary problem = expressive language
• Posterior lesion (~Wernicke's area)
• Wernicke's aphasia; fluent aphasia
• Primary problem = language comprehension

• 1960-1970s
• Studies of aphasia
• RHD group didn't look like "normal" controls
• RHD group didn't look like aphasia group

RH Damage- Typical Deficits:

Communication

• Discourse: verbose, tangential
• Comprehension: can be impaired with longer texts; difficulties with integrating information, understanding INTENT

RH Damage- Typical Deficits:

Attention/perception

• General attentional abilities
• Visuospatial neglect

RH Damage- Typical Deficits:

Cognition

• Organization
• planning
• sequencing
• problem-solving
• reasoning
• judgement

• Traumatic brain injury
• Diffuse axonal injury
• executive function deficits
• limbic system dysfunction
• generalized slowing, processing inefficiencies

Prevention of Brain Damage:

Stroke

• Risk factors
• Warning signs

Prevention of Brain Damage:

TBI

• Risk factors
• Preventive measures

• family history
• race
• African-Americans 2x more likely than Caucasians
• Mexican-Americans more likely than whites
• Age
• Risk doubles every decade after 55
• Gender
• Males (57%) > females (43%) stroke risk

• hypertension
• heart disease
• diabetes
• high cholesterol
• obesity
• smoking, druge use, excessive alcohol use

• migraines
• the pill (especially combined with smoking
• pregnancy and post-partum
• Hormone Replacement Therapy

• All occur suddenly
• weakness/numbness in face, arm, leg unilaterally
• dizziness, loss of balance/coordination
• loss of vision (one or both eyes)
• sudden, severe, unexplained headache
• difficulty speaking and/or understanding speech

• face/limb pain
• hiccups
• nausea
• general weakness
• chest pain
• shortness of breath
• palpitations

• Face - Smile - Is one side drooping?
• Arms - Raise both arms - does one drift down?
• Speech - Speak or repeat a sentence - is sentence correct? Slurred speech?
• Time - Call 911 immediately if any problems are noted

• Normal brain has 130 billion neurons, 150 trillion synapses and 84,500 miles of fibers
• loss per second - 32,000 n, 230 million s, 218 yards fibers, ages 8.7 hours
• loss per minute - 1.9 million n, 14 billion s, 7.5 miles, ages 3.1 weeks
• loss per hour - 120 million n, 830 billion s, 447 miles, ages 3.6 years
• loss per stroke - 1.2 billion n, 8.3 trillion s, 4470 miles, ages 36 years

• 1.4 million head injuries each year
• 50,000 deaths per year
• 50% within 2 hours of injury
• 235,000 hospitalized
• 1.1 million treated in ER & released
• 20% moderate-severe
• 80% mild
• 5.4 million Americans require help with ADLs due to TBI
• Direct & indirect costs in US in 2000 = $60 billion

• Ages 0-14
• 475,000 per year (of 1.4 million total)
• 2600 deaths
• 37,000 hospitalizations
• 435,000 ER visits

1. Falls
2. Motor vehicle/traffic accidents
3. struck by/against
4. assault
5. Unknown
6. other
7. pedal cycle (non-MV)
8. other transport
9. Suicide

• Falls
• Motor vehicle/traffic
• highest rate of hospitalization
• Struck by/against
• collisions
• sports/recreation-related
• 1.6-3.8 million per year
• most = mild, no ER visit
• Assaults
• Firearms = leading cause of TBI death
• 9/10 with firearm-related TBI die
• 2/3 are suicide attempts
• Blast injuries
• leading cause in war zones

• sex (m/f)
• alcohol/drug use
• previous TBI
• sporting activities
• personality type
• school adjustment/social history
• socioeconomic status

• Seat belts
• careseats/booster seats
• Don't drink and drive
• use helmets
• bike, motorcycle, snowmobile, scoot, ATV, skates, skateboards, horses
• Contact sports
• Batting and running bases
• Skiing, snowboarding

• tripping hazards (throw rugs, clutter)
• non-slip mats in bathroom/tub/shower
• grab bars in bathroom
• handrails - both sides of stairways
• improving lighting
• regular excersize

• Safe living areas
• window guards
• gates at top/bottom of stairs

Ventricular system:

General info

• Set of cavities andcanals
• filled with cerebrospinal fluid

• 2 lateral ventricles
• 3rd ventricle
• 4th ventricle

• 3 horns
• Anterior (frontal lobe)
• posterior (parietal/occipital)
• inferior horns (temporal)
• Choroid Plexus
• Generates CSF
• Lined with glia
• ependymal cells
• Foramen of Monroe - connects to 3rd ventricle

• Fills area between L/R thalami
• Connected via cerebral aqueduct to the 4th ventricle

• Brainstem region - between pons and cerebellum
• continues through spinal cord as spinal canal
• foramen of Magendie (medial) and Lushka (lateral)

• Protective membranes surrounding CNS
• Cover brain and spinal cord
• create space to hold CSF

1. Dura mater (outside layer)
2. arachnoid membrane (middle)
3. pia mater (inner)

Dura Mater:

General Info

• Dense, fibrous tissue, double layered
• Periosteal surface
• Connects to inner surface of cranium and vertebral column
• creates epidural space
• Meningeal layer
• connects to arachnoid layer
• creates subdural space

Dura Mater:

Spaces

• Spaces = sinuses
• Superior and inferior sagittal sinus; transverse sinus
• create spaces to hold veins

Dura Mater:

Dural extensions (list)

• Dural extensions = enfoldings
• falx cerebri
• Tentorium cerebelli
• falx cerebelli

Dura Mater:

Falx cerebri

• between R/L cerebral hemispheres
• Creates superior and inferior sagittal sinuses

Dura Mater:

Tentorium cerebelli

• Superior to cerebellum
• Supratentorial space - holds cerebrum
• Infratentorial space - holds cerebellum and brain stem

Dura Mater:

Falx cerebelli

• between R/L cerebellar hemispheres

• spider-web appreance (arachoid trebeculae)
• creates sub-arachnoid space filled with CSF
• Lies along deep surface of dura mater

• Thin, transparent, connective tissue
• adhere to brain tissue
• surrounds blood vessels

• Pia + Arachoid
• Most often involved in meningitis

• Created in lateral ventricles
• Created by Choroid plexus
• flows down through ventricles (via Foramen of Monroe and Cerebral aqueduct)
• Into sub-arachnoid space (via foramen of Megndie and Lushka)
• Re-absorbed by arachnoid vili

• Blockage in ventricular system
• Build up of CSF
• Increased intracranial pressure (ICP)
• increased fluids within skull