the basic structural and functional unit of the nervous system

aka nerve cell

specialized cells which surround and support the neurons

collectively referred to as neuroglia

a bundle of neuon fibers (axons) collected together as a trunk

TRAVELS IN THE PNS

nerve=nerve trunk

never fibers = individual axons making up the nerve trunk

connects 2 hemispheres

examples:

• Corpus Callosum
• Aterior commissure

1. Ideation                               (cognition)
2. Linguistic Planning                (Language)
3. Motor Plannin/Programming   (motor)             
4. Performance-execution          (motor)
5. Feedback                             (sensory)

a collective group of speech disorders resulting from disturbance in muscular control over the speech mechanism due to damage of the CNS or PNS.  Designates problems in oral communication due to paralysis, weakness, or incoordination of the speech mechanism

** NOT AT THE MUSCULAR LEVEL **

1) Perceptual Method - "gold standard" for differential diagnosis; listen and look

2) Acoustic methods - confirms perceptual judgement

3) Physiologic Method - movement parameters; focus on the movement of the speech structures

What are some variables relevant to neurologic and etiologic perspectives?

1) age at onset (congenital vs. acquired)

2) Course

       congenital, chronic, progressive, degenterative

3) Site of lesion - what to expect; understand prognosis; course of treatment

4) Neurologic diagnosis - understand underlying pathology; predictive power --> guides in decisions

5) Pathophysiology (weakness, spasticity, etc.)

1) Speech components involved (respiration, phonation, resonance, artiucation = assessment)

2) Severity - determined along severity continuum (normal <----> profound - where can I get a quick fix/biggest difference)

3) perceptual charactersitics

1. Flaccid
2. Spastic
3. Ataxic
4. Hypokinetic
5. Hyperkinetic
6. Mixed
7. Unilateral Upper Motor Neuron
8. Undertermined

• Myelinated
• tissue underlying cortext
• CNS
• fiber tracts

• fillers/support neurons
• functionally specialized cellts
• "fillers"
• integrate all sensory and motor functiosn of CNS

1. Longitudinal - divides 2 hemispheres
2. Central fissure (fissure of rolando/central sulcus) - divides each cerebral hemisphere into anterior and posterior regions
3. lateral fissure (fissure of sylvius) - courses along the side of the cerebrum - separates frontal and parietal and some of the temporal

Primary Motor Cortex (4)

aka Motor Strip

• Pre central gyrus - anterior to the central sulcus 
• stimulation will result in movement of the corresponding contralateral body part (bilateral innervation)

• internal generation of movements
• **important for motor speech programming**
• **performance of repetitive, sequential motor tasks**
• may use sensory info to organize & guide motor behavior
• linked with B.G. & cerebllum - help make volitioinal movements

• associated with motor speech programming, but has a real role in terms of control, rhythm, phonation, articulation
• strong connections to limbi lobe - mechanics that "drive" or motivate action
• Plays role in: 
• initiation of propositonal speech
• stimulation of site can evoke/arrest vocalization, slow speech, induce dysfluencies
• ***CONTROL OF ACTIVATION & INITIATION OF SPEECH ***

• part of pre-motor cortex
• inferior frontal gyrus
• **anterior to promary motor cortex**
• above lateral fissure
• speech programming

Somatosensory Cortex (1, 2, 3, & 5)

sensory strip/primary sensory cortex

post central gyrus

• Receives tactile & kinesthetic information from different sensory receptors, contralaterally
• helps plan & program for speech - for preparation of motor activity
• proprioceptive = feedback (co-articulation)
• sensory info important for feedback & feed-forward system for speech motor control

1. Taction/Tactile
• pressure; tongue/lips
2. Baroception
• air pressure
• baroreceptors in tracheobronchial aid in regulating air pressures needed for speech
3. Audition/Auditory
• learn to speak; monitor output

Muscle Spindles (striated)

• voluntary
• located in striated (skeletal) muscles
• sensitive to degree of strech in muscle

• located at terminal portion of lateral fissure; parietal association cortex
• processing & integrating mulisensory information:
• tactile, auditory, & visual in preparation for motor activity
• language processing
• phonological storage
• processing & integrating mulisensory info -->feed-forward
• multimodal for sensor - motor control and language production

1. Primary auditory cortext
2. Heschl's gyrus
3. transverse gyrus

-- same region, various names, Brodman's #41

4. Wernicke's Area (22, 41, 42)

• upper portion of lateral fissure & superior temporal gyrus
• primary processor of auditory signals
• receives ino from thalamus via thalamocortical radiations

• interpreting audiotyr info (language)
• phonological processing --> formation of message to send
• Posterior superior part of the temporal lobe
• auditory association cortex

How brain COMPREHENDS speech/language

1. travel from ears to auditory cortext
• encodes acoustic info
2. sends to Wernicke's area
• sort through semantic meanings for words
• syntactic rules are searched to determine relationships
3. Other parts of brain are sent "instructions" on how to respond

1. Wernicke's retrieves from mental lexicon
• constructs sentence that complies w/ phonologic, syntactic, & semantic rules
2. Broca's & other frontal lobe cortices translae code into action --> sends to primary motor cortex
3. Primary motor cortex & other frontal lobe cortices put finishing touches --> send down to cranial nerves
4. Cranial nerves put speech muscles in motion
5. **Wernicke's area monitors output**

1. association fibers
2. commisuural fibers

• connect WITHIN a hemisphere
• connect areas of sensory reception ot association areas that provide meaning to sensory stimulus by comparing with "memories"
• example:
• arcuate fasiculus - connects frontal with regions in parietal & temporal; fibers run anteriour

• 4 bundles of fibers that connect the two hemispheres
• exmaples:
• Corpus Collosum - major link btwn hemispheres; connects homologous areas of the right and left cerebral hemispheres
• Anterior commissure
• Middle commissure
• posterior commissure

Cortical Components (tracts & pathways)

• ** Direct acivating system for voluntary movement = various areas of origination**

1. primary motor cortex
2. premotor cortex
3. supplementary cortex
4. post-central gyrus (feeds from primary sensory area)

afferent and efferent tracts that connect higher and lower areas in the CNS

(both sensory and motor)

• coricalbulbar & corticalspinal TRACTS are arranged in fan like mass of fibers
• collectively known as corona radiata

THESE FUNNEL INTO INTERAL CAPSULE

• corona radiata converges in to compact band (known as IC)
• important b/c containts ALL afferent & efferent fibers that project to and from cortex
• these fibers are in a small concetrated area on the way down to the brainstem and spinal cord
• IC = interconnected w/ thalamus - all afferent & efferent fibers from cortex

Basal Nuclei (Ganglia)

-- group of neurons clustered together

• nuceli = term for CNS (where it lies)
• generalized term for masses of neuron cell bodies that lie deep in the brain
1. Caudate tail
2. Lenticular nucleus/Lenticular Formation
3. Striatum

Globus pallidus + Substantia niagra

they exhert an inhibitory control on the brainstem

What is the major function of the Basal Ganglia?

What happens if there is damage at the B.G.?

• initiates movement & terminating - supresses unwanted motor activity
• important in controlling motor functions of the body

hypokinetic dysarthria (reduction in motion) - Parkinson's Disease - hyperkinetic - excessive movements (ticks, Korea?, etc.)

• major part of diencephalon
• gray matter
• relay center for subcortical & cortical structures for sensory & morot info
• all sensory info converges here (EXCEPT SMELL)
• then distributes to other parts of CNS

1. ventral anterior nuclei
2. ventral lateral nuclei      

 -- these two receive input from Basal nuclei & cerebellum

• controls and integrates the functions of the autonomic nervous system
• regulates pituitary gland
• integrates function of endocrine system
• body temp.
• food/water intake
• emotion
• sexual behavior
• sleep/wake cycle

Cerebellum

"little brain"

• base of occpital love & adjacent to brain stem; posterior to 4th ventricle
• contains about 1/2 of total neurons in CNS
• cortex (thin) made up of gray & white matter
• primary info-receiving part 
• input section(sensory) & output section (motor)
• info arrives via middle & inferior cerebellar peduncles --> connect to : spinal cord, vestibular system, motor control areas

3 sets (white matter):

tracts - information flowing in/out of cerebellum

Can directly coordinate with spinal cord & at a corical level

helps make "online corrections" which are not made at the corical level

movement disorder, resulting in damage to cerebellum

--looks like someone is drunk (slurred speech & poor balacnce/incoordination)

• maintain equilibrium --> balance
• coordnate muscle action
• contributes to syngergy of muscle action (synchronization of muscles as a group)
• make sure muscles contract at right time w/ right force
• speech - allows for smooth flow from 1 articulator to the next

• muscle synergy - coordination & smoothness in time & space of ongoing movements - transitions - essential for fine & skilled movements (speech)
• muscle tone
• movement range, strength & velocity
• maintenance of body equilibrium
• Vital control of very rapid muscular activity

• generate emotion and visceral responses
• may provide motivational & intentional aspect to comm.
• instinct

• mutism
• bilateral hippocampal lesion
• RECENT MEMORY DEFICIT -- hippocampa & amygdala

1. Midbrain
2. Pons
• cerebellum is connected @ pons by cerebellar peduncles
3. medulla

Spinal Cord

(inferior to medulla)

• Foramen magnum - hole that allows spinal cord thru to cortex/skull
• contained in vertebral column
• contains Spinal nerves (PNS)

Posterior Horns (dorsal horns) =

Anterior horns (ventral horns) =

Posterior horns/dorsal horns = sensory - white matter

anterior horns/ventral horns = motor - gray matter

back/dorsal/posterior portion

SENSORY

• 12 paired cranial nerves
• 31 paired spinal nerves

• reception of general sensory information from head region and control of muscles of head (esp. facial expression & masication)
• vision, hearing, balance, smell, and taste

• motor nuclei in brain stem
• axon of nerve cells innervate/activate muscle = LMN
• group of cells in brainstem (LMN/alpha motor neurons) receive impulses thru cortical bulbar tract
• this tract originates in PYRAMIDAL cells -- inferior part of precentral gyrus
• tract descends thru corona radiata & internal capsule
• Most cross over -- deccusation in medulla (except VII & hypoglossal)

• sensory = outside of CNS= GANGLIA --> PNS
• some sensory nerve cells located in sensory organ (ear or eye)
• sensory info enters brainstem & synapses in sensory nuclei of cranial nerve
• axons cross midline & ascend to synpase in thalamus then go to somatosensory cortex

Crancial Nerves

important for speech

5) Tigeminal - Sensory & Motor : facial sensation

7) Facial - Sensory & Motor - facial expression & taste

8) vestibulocochlea/acoustic - sensory - hearing; sense of balance

9) glossopharyngeal - Sensory & Motor - taste sensation & swallowing

10) Vagus - Sensory & Motor - swallowing & taste sensation

11) Accessory - Motor - Controls nexk & shoulder muscles

12) hypoglossal - Motor - Tongue Movement

• Motor - muscles of mastication
• Sensory - face & anterior parts of the head, includes teeth
• 3 branches:
• opthalmic - sensory
• maxillary - sensory
• mandibular - sensory & motor

• Motor - muscle for facial expression
• Sensory - role in mediating tast ANTERIOR 2/3 of tong

• Acoustic branch - acoustic sensation stimulates at the cochlea
• Vestibular Branch - acceleration & position - communicates with vestibular nuclei

• motor - muscles to pharynx
• sensory - taste POSTERIOR 1/3 of tongue
• **Helps regulate salival **

• 3 branches
• recurrent laryngeal nerve - goes down & comes up
• pharygeal branch
• superior laryngeal branch
• efferent/motor innervates INTRINSIC laryngeal & pharyngeal muscles 
• taste info from epiglottis is mediated by vagus
• has afferent & efferent - toracic & abdominal viscera
  

• cranial & spinal components
• innervates trapezius & sternocleidomoastoid muscles
• works w/ vagus to innervate intrinsic larygeal muscles, parynx, and soft palate (TENSOR VELI PALATINI - innervated by trigeminal V)

Spinal Nerves:

How Many?

mortor enters where?

sensory infor enters where?

31 pairs emerge from spinal cord

Motor = VENTRAL = Anterior (striated - volitional movement)

Sensory = DORSAL = posterior ** remember parietal & occipital are in the PACK of the brain **

carry general sensory information from the skin, muscles, and joins to the trunk & limbs

also, concerned with motor control of trunk & limb muscles  (innervation)

What is the sensory pathway

(sensory information ascending)?

1. information receieved from peripheri
2. dorsal root ganglia of spinal nerves
3. dorsal horn
4. sensory info ascneds along fiber tracts
5. relay station in thalamic nuclei
6. passes info to cortex (some info passed thru cerebellum via cerebellar peduncles)

Motor pathway of spinal nerves

(descending tract)

1. motor neurons in ventral horn
2. motor roots emerge here
3. reach muscles of trunk/limbs

Lower Motor Neuron aka

alpha motor neuron

• motor neurons in ventral horn of SC
• innervate striated musculature - axons from nerves in PNS
• FINAL COMMON PATHWAY - to get to muscle - controlled by higher level centers (cells in primary motor strip)

• axons leave spinal cord within spinal nerve to specific muscle
• axons can innervate several muscles & muscles can be innervated by several axons

• a single LMN (alpha motor neuron) and the MUSCLE FIBERS it innervates
• LMN = axon/dendrites + muscle fibers it innervates = Motor Unit

fine control = innervates ??? muscle fibers

not percise control - innervates ?? muscle fibers

fine control = innervates few muscle fibers

not percise control = hundreds of muscle fibers

PLACE

termination (looses myelin) axon of MN enters muscle

Muscles consist of:

extrafusal fibers

intrafusal fibers

• extrafusal fibers - large mass of striated muscl & outer portion - innvervated by LMN
• intrafusal fibers - contain spindle fibers

• all efferent must pass through to activate muscles - no matter where it originates
• originates in PREFRONTAL CORTEX (pyramidal cells)

• within striated muscles
• sensitive to stretching
• run // to extrafusal fibers
• when extrafusal fibers are strechted, so will the spindles (intrafusal fibers)

** INNERVATED BY GAMMA MOTOR NEURONS***

• LMN innvervates extrafusal muscle fibers
• stretches muscle
• stretches intrafusal (spindles)
• which are innervated by GMN
• sensitive to stretch --> sends signal back to DORSAL (sensory) portion
• impact send signal to AMN/LMN "no more stretching"
• send signal all over again to contract the muscles to resting postion
• REFLEX ARC
  

Where do Gamma motor neurons lie?

What are they influenced by?

What is the role of Gamma Motor Neurons?

• along the AMN in ventral spinal horns (motor/front)
• synaptic input from cerebellum, B.G., and indirect pathways (NOT CORTICAL SPINAL TRACT) of CNS
• regulate contraction of Intrfusal fibers
• allows muscle spindles to be adjusted to the status of extrafusal fibers
• enhances sensitivity of muscle control

maintaining muscle tone

** if we did not have the reflex arc - we would have flaccidity**

Nourishment of the Brain:

Blood  complex fluid with liquid and solid components

• plasma - yellow fluid
• solid components (particulates)
• red corpuscles (erthrocytes
• carry O2 from lungs to cells of body
• formed in bone marrow
• avg life 120 day - removed by spleen
• white corpuscles - leukocytes
• platelets - thrombocytes

The brain does not supply glycogen - energy source for metabolism

needs constant supply of blood

if not will lead to necrosis - neuron death due to lack of O2

• Internal Carotid
• Anterior Cerebral artery
• Middle Cerebral artery
• **significant for speech & language*
• susceptible to strokes
• Basilar artery
• posterior cerebral artery
• cerebral arteries

What arteries are formed in the back/posterior portion?

What arteries are formed in the front/anterior portion?

Back/Posterior

           1) subclavian

           2) vertebral fuse together to form

           3) Basilar artery

           4) posterior arteries

Front/Anterior

          1) Internal Carotid

          2) MCA (on each side)

          3)anterior carotid (each side)

          4) anterior communicating artery

returns through the venous system

dura venous sinus (drain blood) --> jugular vein --> heart

Meninges - wrappings of the brain

Ventricular System - cushion - floating in cranial vault - series of internal cavitites that contain cerbrospinal fluid

**bone, meniges, and fluid protect the brain & spinal cord**

1. dura mater (tough mother)
• extradural space: between skull and dura
• subdural space
2. Arachnoid (spider mother)
• tiny filaments - cushion brain
• subarachnoid space
3. Pia mater (delicate mother)
• closest to cerebral cortex

• separates cerebral hemispheres
• extension of dura mater; fibrous dense; keep 2 hemispheres from rubbing & rotational surfaces in cranial vault

"tent over cerebellum:

divides cranial cavity into cerebral & cerebellar regions

Cerebrospinal Fluid (CSF) - location

& what produces it

• fills subarachnoid space & ventricular system (cavities of brain)
• Choroid plexus - withing the ventricles (esp. lateral ventricle)
• tuft like substance - produced in lateral ventricle (mostly)

1. CSF flows from 2 lateral ventricles
2. foramen monroe --> 3rd ventricle
3. cerebral aqueduct --> 4th ventricle
4. 3 apetures
• median apeture - foramen of magendie
• lateral apeture - foramen of luschka
5. Subarachnoid space --> venous system
• venous system @ superior sagittal sinus via ARACHNOID VILLI

• protective function
• shock absorber
• affords protection against some expandion of intrac cranial contents
• cannot expand in 1 area without compromising another
• nutritive function - maintains metabolism
• spinal tap: a way of sampling the CSF

Ventricular system:

ventricle

• Ventricle: cavities that contain CSF
• CSF Flow - circulates, cushions, and maintains metabolism
• ventricle + subarachnoid space = ventricular system
• CSF circulates thru ventricles & subarachnoid space - absorbed in arachoid villi in brain or leptomeninges w/in subarachnoid space in spinal cord

Circle of Willis - how is it made up (arteries)

vertebrobasilar + carotid = circle of willis

• all vessels supplying the brain & cerebral hemispheres come from AORTIC ARCH
• carotid originates with ICA (from neck); ICA separates into anterior and cerebral arteries.  The 2 ACA connected to each other anterior communicating artery

• vertebrobasilar system begins w/ 2 vertebral arteries - enter brainstem via foramen magnum
• join to form basilar artery
• branches supply brainstem, cerebellum & portions of cervical spinal cord
• posterior cerebral arteries are branches of verebrobasialr system

• influence all levels of nervous system
• actions have direct bearing on speech
• dysfunction can lead ot motor-speech & other neurologic disorders

• Structures:
• reicular formation & ascending projection pathways, portions of thalamus, areas of cerebral cortex
• Crucial to maintaining:
• wakefulness, consciousness, awareness of environ., selective & sustained attn.

• rely on sensory feedback for normal functions
• found at ALL major anatomic levels of nervous sys.
• includes:
• perpheral receptor organs, afferent fibers in CN, SN, & Peripheral nerves, dorsal root gangllia (sensory receptors to CNS), ascending pathways in brainstem, portions of thalamus, thalamocoritcal connections

• all major anatomical levels of nervous system & directly responsible for all motor activity involving STRIATED muscles
• includes: efferent connections to cortex, descending pathways to motor nuclei of CN & SN, striated muscles
• essential to normal reflexes, mainintain normal muscle tone & posture, planning, initiation and ctrl of voluntary movement

• neuron - most important structural element of nervous system
• cell body = central processing unity (soma)
• axons: conduct electric energy away from cell body to next
• dedrites - receieve - gather information transmitted from other neurons

• place of communication btwn neurons
• axons & dendrites communicate - separated by synaptic cleft
• neuromuscular synapse - acetylcholine released - if sufficent, leads to movemtn thru contraction of muscle fibers

results from integrated activity of astounding numbers of neurons conducting impulses at many levels of CNS

activites of neuons that join to carry out volitional movement of speech production (join together to accomplish particular goal)

Nerve

**to know and to love

Peripheral nerve

• Nerve: group of nerve fibers that travel together in PNS
• peripheral nerves - travel btwn CNS & peripheral end organs
• from spinal cord to muscles - spinal nerves innvervate for respiration

Tracts & Pathways

commissural tracts, association tracts, projection tracts

• Tracts & Pathways - CNS - group of nerve fibers that travel together
• Commissural tracts - connect homologus areas in 2 hemispheres - CC
• Association tracts - connect cortical areas withing a hemisphere "associate w/ neighbor"
• projection tracts - afferent & efferent tracts that connect higher & lower areas in CN

• Glial cells - fillers & support - produce myelin in CNS
• Schwann cells - produces myelin in PNS
• Nodes of Ranvier - small space between myelinated segments of peripheral nerves - allows for impulses to travel quicker
• saltatory trasnmission - the electrical impusles that skips from node to node - speeding up transmission

Evolution or course

Transient, improving, progressive, exacerbating0remitting, stationary

• Transient - symptoms resolve on their own - temporarty
• Improving - severity reduced, but symptoms have not resolved/gone away
• Progressive - continue to get worse
• Exacerbating-remitting - symptoms develop, resolve, and then recur (& are exacerbated) - MS
• stationary - remain unchanged - maximum severity

1. degenerative - loss/cells dying; structures & function; progressive & chronic - long standing & continue over time
2. inflammatory - infection - outpouring of white blood cells (ex. meningitis)
3. toxic-metabolic - vitamin deficiencies; biochemical disorders - alter neuronal function - acute onset, but can change over time to subacute; impacts liver & kidney function
4. neoplastic disease - tumors

• identify precipitating event (except subdural hemotoma)
• open vs closed
• coup vs contra coup
• diffuse axonal injury is view as principle cause of persistent severe neurologic deficits

• CVAs/ stroke
• ischemic attack/occulsive - clot formed - lack of blood supply - results in lack of O2 - blockage of blood vessel (artery)
• embolic - sudden onset
• thrombosis - blockage @ site within artery - usually bending or bifercating - gradual build up
• TIA - temporary occulsion of an artery
• hemmorrhagic - too much blood; rupture in blood vessel - collection of blood (hematoma)

Final Common Pathway

**to know and to love**

• LMN - peripheral mechanism thru which all motor activity is mediated
• last link in chaing of events for motor activity
• extrafusal fibers = direct contact w/ LMN
• axon of LMN leaves brainstem thru CN to specific muscle
• Gamma Motor nurons are strongly influenced by cerebellum, BG, and indirect pathways
• muscle tone - innervate intrafusal muscle fibers

will abolish or reduce reflexes by removing or weakening the trigger for them

damage to a single LMN doees not eliminate muscle contractions - may lead to weakness or paresis

discharge of motor unit - spontaneous - input to LMN changed due to damange

  -- borders of tongue (common area)

sensory - pain, thermal & tactile sensation from face & forehead; mucous membranes of nose & mouth, teeth, gums, hard palate

motor - muscles of mastication, tensory tympani, tensory veli palatini

motor: stapedius muscles, muscles of facial expression

sensory - taste (2/3 anterior tongue)

LMN = paralysis on ipsilateral side of face - fasiculation may be seen on chin

motor: sylopharyngeus muscle of pharyn

sensory : pharynx, tongue, eustachian tube

**lesions here are usually accompanied by vagus nerve damage**

motorr: soft palate, pharynx, larynx

sensory : same structures

**superior & recurrent laryngeal nerves are responsible for all motor activities involving phonation & swallowing**

contains cranial and spinal

innvervates neck muscles

motor: all intrinsic & external (except palatoglossus) tongue muscles

sensory: taste & tactile information

damage can lead to atrophy, weakness, fasiculations, tongue will deviate to side of lesion

22 pairs - responsible for respiration

intercostal & abdominal muscles are spread thru thoracic portions of spinal cord

phrenic nerve = those suppling the diaphragm arise from 3rd, 4th1 and 5th cervical segments

Direct Activation Pathway

**to know and to love - TEST**

coticalbulbar (CN) + coricalspinal (SN) = direct activation system

UMN inlcude neurons that regulate LMN and are controlled directly or indirectly by cortex, cerebellum, or BG

UMN controls coricalbulbar & cortical spinal

if it travels from cortex = direct activation pathway

indirect route is still controlled by UMN system

contained entirely within CNS

**DOES NOT INCLUDE BG & CEREBELLAR CONTROL CIRCUITS **

does include coricalbulbar & corticalspinal

predominatly direct activation pathway

Cortical components

**to know and to love: test**

the direct activation pathway originates in the cortext of each cerebral hemisphere

Pyramidal Tract:

- primary motor cotex - precentral gyrus

- premotor cortex

- supplementary motor area

- post central gyrus - parietal lobe

Tracts

**to know and to love: test**

• axons of direct activation pathway for speech travel in Pyramidal Tracts
• **Corticalbulbar & Corticalspinal tracts**
• arranged in fan-like mass of fibers that converges from cortex to brainstem
• fan like mass = corona radiata
• converge & form internal capsule

Internal Capsule

• corona radiata converge into compact band = IC
• important regiong b/c it contains ALL afferent & efferent fibers that project to and from cortext
• both sensory and motor

Destination of UMN

**to know and to love: test**

• UMN innervate LMN on both sides or contralaterally (typical)
• direct activation of speech cranial nerves = bilateral
• tongue & lower face are innervated predominatly by contralateral corticalbulbar fibers

Direct activation pathways are crucial to voluntary motor activity, especially consioucly controlled skilled, discrete, and often rapid movemnts ( speech)

these movements are considered voluntary

1. striated muscles represented in upside down along motor strip
2. # of motorneurons devoted to striated muscles, not dependent upon muscle size, but degree of control.  Distribution reflects primary function of direct activating system for speech (discrete control of fine movements)
• the finer the movemnt, the more control needed, and the more motor neurons that are devoted
3. motor cortex organized in columns of neurons extending vertically from surface of deep layers of cortex
• movements are represented in cortex, not in the muscles
  

Indirect ACtivation Pathway & Speech

**to know and to love: test**

• source of input to LMN
• often referred to as extrapyramidal tract or indirect motor system
• indirect = mulitple synapses between origin in cerebral cortex & activation of LMN

1. coricoreticular tracts
2. corticorubral tracts
3. reticulospinal tracts
4. vestibulospinal tracts

projects from cortex to reticular formation  - arises fom motor, premotor, and sensory cotex (in brainstem - pons & midbrain)

regions have ascending & descending projections - as well as projections to cerebellum & cranial nerve nuclue

cotex --> red nucleus

cortex to LMN, fibers are sent from cortex to red nucleus via corticalrubral tracts

• cortex --> reticular formation --> spinal cord (nuclei)
• reticular activating w/ hypothalamus
• terminate @ gamma motor neuron (stretch reflexes = muscle tone)
• inhibit reflexes - maintain steady state
• mediates consiousness & ascending sensory information & has complex effects on LMN
• inhibit flexor - contributes to muscle tone

• arise from vestibular nuclei
• located in 4th ventricle in pons & medulla
• receive sensory info from vestibular apparatus of ear & from cerebellum
• tracts project to brainstem, cerebellum, and spinal cord
• terminape/impact both LMN & GMN
• FACILITATES - reflex activites & spinal mechanisms that control muscle tone

• oval mass of cells in midbrain tegmentum
• receives corical projections thru corticorubral tracts
• **relay station** between a pathway from cerebellum to ventrolateral nucleus of thalamus & ultimately the cortex
• **circuit**

• Desintation:influence activites of both GMN & LMN of the FCP
• Function: : helps regulate reflexes, maintain posture & tone
• systems maintain and carry out voluntary movement subconsiously
• ensure specific speech movements occur w/o constant or variable interference w/ speed, range & direction (**TIMING**)

• integrate/help control diverse activities of many structures & pathways involved in motore performance
• **DO NOT HAVE DIRECT CONTACT WITH LMN**
• can contribute, but not contact
• influence movemtn thru their input to cerebral cotex & from there, via the direct & indirect activation pathways
• Basal Ganglia & Cerebellar = two circuits

Basal Ganglia Control Circuit

Striatum is composed of???

• B.G. = caudate nucleus, putamen, and globus pallidus
• **THE MAJOR EFFERENT PATHWAYS OF B.G. ORIGINATE IN GLOBUS PALLIDUS**
• Striatum: caudate & putamen - reception portion of B.G.
• sends efferent fibers to sub. nigra & is major source of input in Globus Pallidus
• rich w/ acetycholin & dopamine (neurotransmitters) - important in motor ctrl
• Striatum -->GP (output) --> motor function
  

• Lentiform nucleus : Putamen & Globus Pallidus
• sub. nigra & subthalamic nucleus are anatomically & functionally closely related to BG & activities as a control circuit

• for movement, not well understood
• as a group important for maintaining normal posture & static muscle contraction
• regulating movements - amplitude, velocity & possibly the initiation of movement
• **imporatnt in generating components of motor programs for speech**

Cerebellar Control Circuit & Speech

(cerebellar + connections = cerebellar control circuit)

anterior, vermis, posterior, flocculonodular

• Cerebellum
• anterior, posterior & flocculonodular lobes
• vermis - mid portion of cerebellum
• flocculonodular - equilibirium & orientation of head & eyes
• anterior - posture, walking, gait, tone in trunk
• posterior - movement - corrdination - muscle tone

• leave and enter thru ingerior, middle, and superior cerebellar peduncles
• Peduncles
• inferior - afferent fibers - sensory, few efferent
• middle - afferent - decussate in pons - sensory primary
• superior - motor - efferent

Purkinje Cells

& dendate nuclues ( one of the cerebellar nuclei)

• primary output neurons of cerebellum; axons synapse in deep cerebellar nuclei
• dendate nucleus - active in initiating speech, regulating posture & executing pre-planned motor tasks
• most involed w/ speech control are in VERMIS & cerebellar hemispheres!

• primary motor cortex&premotor regions of cortex -->
• lateral cerebellar hemispheres via pontine nuclei
• RETURN: deep cerebellar nuclei & ventral thalamic nuclei

**this loop is important to planning & programming learned movemnts**

• descending corticopsinal & corticalbulbar fibers-->
• intermediate aspects of cerebellar hemispheres
• RETURN to primary motor cortex: deep cerebellar nuclei & ventral thalamic nuclei

** important b/c provides cerebellum with immediate intentions to carry out the movement**

• long-range planning of movement
• input from the cortex prepares the cerebellum to check the adequacy of speech output as feedback from muscles, tendons, & joints
• **gives feedback**
• The exclusive inhibitory output from Purkinjie cells results in smooth coordinated movemtns (inhibitory output)
• interprets infor from muscle spindles - what needs to take place
• interprets sensory infor & integrates w/ cortex about upcoming movement goals

Conceptual-Programming Level & Speech

(Brain with all the arrows)

What are the 5 stages?

• highest level = conceptual
• establish goals & what is needed to be achieved 

1. conceptualization
2. spatial-temporal planning (linguistic planning) - phonemic
3. motor planning
4. performance
5. feedback

• developing a desire to do something & establishing a purpose or goal for action
• neural basis cannot be localized

• cognitive operations on abstract rules
• requires: attn, retrieval & working memory
• also, ability to discard from active processing utterances that have already been formulated and executed
• centered in dominant hemisphere perisylvian cotex - temporoparietal & posterior frontal cortex = PERISYLVIAN FISSURE

• translation of abstract linguist-phonologic representation into a code can be used by motor system to generate movmt in speech
• must meet condition (can achieve same goal in # different ways, but in speech must be in a way that is acceptable - perceptually)
• can achieve the same mvmt goal in # diff ways, but in speech it must be perceptually acceptable

apraxia has _______ erros

dysarthria has ______ errors

• apraxia - programming level - irregular erros
• dysarthria - execution/performance leve - same errors

temporal-spatial (direction - where is the target) overlap of movements nevessar for the production of more than 1 sound occuring at the same time

**motor speech is continuous & context dependent activity in which articulators reach targets reliably despite considerable variability in starting position**

premotor & supplementary motor areas

• somatosensory cortex & supramarginal gyrus - play a role in integration of sensory information in preparation for motor activity - feed into area
• Insula - implicated in disorders of motor speech programming  - damage in insula impacts tissue there --> acquired apraxia of speech

What is the role of senstation for speech-motor programming?

** sensory infor is very relevant to normal function - guides us in movmt of speech **

1. auditory & sensory input have diverse inpu to speech motor system
2. commands leading to production of specific ounds CANNOT be invariant because the actions depend on the phonetic & physical environment
• knowledge about hwere structures will come from and their movement velocity seems essential
3. descending pathways from higher brain centers can influence sensory processing at brainstem & spinal levels - sensory pathways are pretuned & sensitive
4. abnormal processing of sensory info may have an impact on certain dysarthrias
   

Speech-Motor Planning(programming): 

Control Circuit Influences

• **BG important to preprogramming & regulation of slower components of speech movements - provide postural support for rapid speech movement such as those involved in articulation**
• **Cerebellar control circuit - programming & regulating more rapid speech movements** synergy of motion

• Performance - dysarthria - level of motor control that activates motor neurons, muscle contractions, & movement
• muscles execute motor commands from PMC (comes via nerves - corticalbulbar & corticalspinal --> innervate LMN-->motor nuclei --> muscles contract)
• Feedback- sensor info about ongoing & completed mvmts - helps us self-correct

• group of nuclei (deep) & pathways comprised of olfactory area, hypothalamic & thalamic nucle & the limbic lobe of the cortex
• cruicial role in visceral & emotional activity & mediates info about internal states
• limbic cortex important regulating memory & learning, modulating drive or motivation & influencing affective components of experiences

programming happens in left hemisphere, transmitted to right hemisphere via CC - motor pathways carry out the program in coordination w/ left hemisphere

it is believed RH plays a role in prosody & contributes to perception

• contributes to monitoring sensory input, maintaining alertness & attention, focusing attention & refining motor activity
• influencesL emotional & propositonal content (conveying meaning) & neuromuscular adequacy of speech

• circuitry  necessary for normal speech production
• **sensory processor**
• relay station for control circuits (BG & cerebellum)
• direct ties to cortical langauge & motor-speech systems -->lesion in area = subcortical aphasia
• integrative role in attention & vigilance
• role in limbic system

1. description
2. problem detection
3. establishing diagnostic possibliites & elimiate diagnosis
4. establishing a diagnosis
5. specifing severity

• Description - characterizes features of speech & make diagnosis based on this
• Bases for desction derived from:
• pt's hisotry & description of problem
• oral mech exam
• perceptial characteristics of meech & results of standardized test

• diagnosis - depends upon sufficient, valid, and reliable data - must have
• description - is little value, when the goal is diagnosis - look for cluster of symptoms

• if diagnosis cannot be achieved, describe in detail
• "patient exhibits symptoms with..."
• processing of narrowing the diagnostic possbilities & arriving at a specific diagnosis

• always should be estimated
• match complaints of patients
• influences prognosis/management
• baseline measures (Refer back to in future) how far in the disease/disorder & helpts plan treatment
• specifying severity is part of descriptive process

What are the 3 essential components of a motor speech exam?

With the information:

1. history
2. identification of salient speech features
3. identification of confirmatory signs

With the information:

* a diagnosis is made

* recommendations formulated

*resuls communicated to patient, referring physician, & others

1. strength - proficient enough to perform normal function (and look at reserve strength)
2. speed - reduced or variable
3. range - rest, stationary, & movement - are they hitting their artic targets? distance traveled, percise?
4. Steadiness - unstead? rhythmic or arrhythmic?
5. Tone - increased, decreased, or variable?
6. accuracy - movement inaccurate (consistent/inconsistent)

• additional clues about location of pathology
• can be found in speech or non-speech muscles
• non-speech: gait, hyperactive reflexes; pathologic reflexes; changes in other muscles
• speech look for change in: 1) atrophy 2) pseudobulbar affect 3) change in cough
• **a particular motor speech diagnosis does not require that confirmatory signs be present**

1. history
2. examination of oral mech during nonspeech activities
3. assessment of perceptual speech characteristics
4. assessing intelligibility

1. at rest
2. during sustained posture
3. during movement

Face:

at rest, sustained posture, during movement

• rest: symmetry, expression, involuntary mvmts, presencse of fasiculations/tremor
• sustained posture - allows additional info of symmetry, ROM, strength/tone, abiltiy to maintain posture;
• movement - during speech & emotional responses, rnage & symmetry of facial movement & expressiveness should be noted

Jaw

at rest, sustained posture, movement

• at rest- asymmetry? habitual mouth breathing? drooling? involunatry quick or slow mvmts
• sustained posture - deviate to 1 side? can pt resist examiner's attempt to open/close jaw
• movement - symmetry of opening/closing and ROM during speech & spontaneous mvmts
• AMR - alternating motion rates

Tongue

at rest, sustained posture, during movement

• rest - size, symmetry, presence of fasiculations
• sustained posture - protrude tongue, deviation? can pt resist examiner's attempt to push the tongue back into mouth; can pt push out cheeck on both sides w/ tongue
• movement - move tongue side to side rapidyly; observe speed, regularity, and ROM

Velopharynx

at rest & during movement

• rest - palate hang low in mouth? ; palatal arches symmetry? pontaneous rhythmic or arrhytmic beating movements of palate?
• movement - palatal movement symmetric? evidence of nasal airflow or does resonance change during vowel prolongation?

• vocal adduction/abduction
• presence of inhalatory stridor - audible noise when breathing in
• **only look at when structured lesions or LMN lesions of the laryngeal branches of the vagus nerve are a possiblity**

• posture normal?
• does pt complain of shortness of breath?
• breathing rate irregular?

Reflexes:

normal vs primitive

• normal - reflex whose presence is a reflection of normal nervouse system function (absence can reflect PNS pathology)
• gag
• primitive - present during infancy, but disappears during nervous system maturation (presence in adults, often associated with CNS pathology)
• jaw jerk, sucking, snout

• pathological relex
• contraction of masseter & temporalis muscles
• lead to closing
• bilateral UMN disease above level of mid-pons
• Spasticity

• UMN disease - present with dementia's
• tongue blade @ lateral border to midline - see a prusin/pouting of lips = pathological reflex

• index finger run along filtrum - lightly tap - puckering or protursion of lower lip
• incidence doubles as you get older (60+ years)

• testing for non-verbal apraxia (NOVA; oral apraxia; Bucofacialapraxia)
• observations focus on ability to perform w/o off target aprroximations, frank erros, or a frustrating awareness that performance is incorrect w/ accimpanying attempts @ self-corrections

1. vowel prolongation
2. AMRs / diadochokinetic rates
3. SMR
4. contextual speech
5. stress testing

• vowel prolongation - keep in mind respiration, but look at phonotation - respiration can affect phonation
• AMR - looking at speed & regularity of movements of jaw, lips, & tongue
• dysarthrias = abnormal or irrecular

• sequential motion rate - measures ability to move quickly from articulatory postion to another; useful for apraxia of speech
• increase length/complexity = increase in errors
• contextual speech - evaluating & integrated function of all components of speech
• conversational sample; narrative (describe picture); read passage

• patients performance w/ fatigue overtime
• should be pursued when LMN weaknes of unknown cause is present or when pt complains of rapid/dramatic changes in speech w/ continued speaking

• apraxias - no omissions; they have anticipiratory erros - make production harder
• dysarthrias - simplification; have omissions and distotions of sounds
• impercise prodcution does not necessarily mean a salient sign for dysarthrias
• LH anteriorly - suspect apraxia

mild/moderate imparied

mute

mismatch

• mild/moderately impaired - SMR repeat complex multisyllabic words & sentences (Methodist & episcopal; zip, zipper, zippering)
• mute - sing song/tune; count (automatic speech) imitate production CVC
• mismatch - btwn complex voluntary taks & simpler automatic taks increase liklihood that apraxia is apparent (not dysarthria)

dysarthria - Frenchay Dysarthia Assessment (FDA) - involves swallowin - helps distinguish types

apraxia - Apraxia Batter for Adults (ABA) - no published norms (general guidelines), can quantify diagnosis & severity

• dysarthrias - affect speech intelligibility - can estimate a %
• changes due to environment, complexity, and predicability of conversation
• poor, fair, good
• get idea of sig. other/primary comm. partner - how much on a day to day basis can you understand for familiar topic vs. unfamiliar?