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Flashcards in Defining Motor Speech Disorders Deck (128):
1

Neurologic process of speech production involves (3):

1. Cognitive-Linguistic Process (Aphasia)
2. Motor Speech Programming (apraxia)
3. Neuromuscular Execution (dysarthria)

2

Cognitive-Linguistic Process –

the aspect of speech production involving an intention to communicate which is organized into the verbal symbols that follow the rules of language. (Aphasia)

3

Motor Speech Programming –

the intended communication has to be executed by the neuromuscular system. To do this the speaker selects and organizes the sensorimotor programs that cause the appropriate speech muscles to be activated at the right time. This is the speech programming process. (apraxia)

4

Neuromuscular Execution –

The CNS and PNS innervate the necessary muscles of respiration, phonation, articulation and resonance to produce desired words. (dysarthria)

5

Motor Speech Disorders:

Disorders of speech resulting from neurologic impairment affecting the motor programming or neuromuscular execution of speech (2):
-apraxia of speech
-the dysarthrias

6

Types of Motor Speech Disorders (2)

Dysarthria & Apraxia

7

Dysarthria:

Collective name for group of motor speech disorders resulting from disturbances in muscular control over the speech mechanism due to damage of the CNS or PNS.

Can result in paralysis, weakness, or incoordination of speech musculature.

8

Dysarthria can affect which speech subsystems (5)?

All speech subsystems:
1. Respiration
2. Phonation
3. Resonance
4. Articulation
5. Prosody

9

Site of lesion for Dysarthria:

CNS
or
PNS

10

Types of Dysarthria – developed by Darley, Aronson & Brown (6)

1. Flaccid
2. Spastic
3. Ataxic
4. Hypokinetic
5. Hyperkinetic
6. Mixed

11

Apraxia:

Neurogenic speech disorder resulting from impairment of the capacity to program sensorimotor commands for the positioning and movement of muscles for volitional production of speech.

Occurs in the absence of weakness.

12

Can apraxia and dysarthria co-occur with aphasia?

Yes, both apraxia and dysarthria can co-occur with aphasia

BUT apraxia more commonly co-occurs with aphasia

13

Apraxia of speech can affect which subsystems of speech (2)?

1. Articulation – may be inconsistent errors (?), difficulty with initiating speech

2. Prosody – due to starting and stopping in self-correcting

14

Does the course of motor speech disorders depends on etiology?

Yes

15

Course of disease for motor speech disorders (5):

1. Transient – symptoms don’t last, they disappear completely

2. Improving – things are improving but some symptoms are still there – just not as severe.

3. Progressive – symptoms don’t get better, they continue to get worse or new symptoms appear.

4. Exacerbating-remitting – symptoms occur, then get better, then occur again; gets worse, then better, etc.

5. Stationary – symptoms remain unchanged after they have reached maximum severity.

16

Treatment of motor speech disorders...

varies depending on type of dysarthria

i.e. for progressive course goals will be different than for developmental or transient

17

How do symptoms develop for motor speech disorders?(3 types)

1. Acute – comes on quickly within minutes
2. Subacute – comes on within days
3. Chronic – comes on within months

18

Most motor speech disorders are associated with...

chronic disorders

19

The Central Nervous System includes:

1. Brain
-Cerebrum
-Brain stem
-Cerebellum
2. Spinal cord
*areas encased by bone

20

4 Lobes of the cerebrum:

Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe

21

The cerebrum is made up of:

Cortex – outer layer (bark)
Gyri – ridges
Sulci - valleys

22

The Cerebellum's job:

Modifing cortical activity

23

The 3 lobes of the cerebellum are:

1. anterior
2. posterior
3. flocculonodular

-Has 2 hemispheres, right and left
-Vermis – midportion

24

3 Parts of the brain stem:

Midbrain – links cerebrum to brain stem page 41
Pons – bridges to cerebellum
Medulla – controls respiration

25

Midbrain (place):

links cerebrum to brain stem

26

Pons (place):

bridges to cerebellum

27

Medulla (function):

controls respiration

28

Are the bones of the skull separated or fused?

Fused -protective device- also hampers at times when expansion needed

29

4 anatomic levels of the CNS:

1. Supratentorial
2. Posterior
3. Spinal
4. Peripheral

30

Supratentorial level of the CNS:

Made up of anterior & middle fossae

Contains the paired frontal, temporal, parietal & occipital lobes AND basal ganglia, thalamus, hypothalamus & cranial nerves I & II

31

Posterior level of the CNS:

Made up of posterior fossa

Contains brainstem, cerebellum & cranial nerves III-XII.

32

Fossae –

3 cavities in base of skull

Fossa – ditch

33

Foramina

Holes in fossae where cranial nerves exit skull

34

Where do cranial nerves II-XII originate?

In brain stem at the posterior fossa level

35

Where do cranial nerves I + II originate?

In the supratentorial level
Cranial nerves important for speech originate at this level, but are part of the PNS.

36

Are cranial nerves part of the CNS or the PNS?

PNS

but, they originate at the supratentorial (I + II) or Posterior level (III-XII) of the CNS

37

Spinal level of the CNS:

Spinal cord begins at lower end of medulla, surrounded by bony vertebral column

Spinal cord ends at first lumbar vertebrae.

38

Peripheral level of the CNS:

12 pairs of cranial nerves
31 pairs of spinal nerves
exit skull through foramina.

39

Why is it important for speech to have pairs (left + right) of cranial nerves?

Protection

40

Where do cranial nerves emerge from?

base of brain (brainstem) and penetrate skull through foramina to reach sensory - motor targets

41

Meninges (covering of the CNS) consist of 3 layers:

1. Dura mater-outer membrane -2 layers fused together
2. Arachnoid mater - below dura, loosely covers brain
3. Pia mater-innermost layer, closely attached to surface of brain

42

Spaces around the meninges (3):

1. Epidural space-between dura and bone

2. Subdural space-beneath dura (infection can develop in these 2 spaces due to trauma, blood & pus pool here)

3. Subarachnoid space-beneath arachnoid –filled with CSF, connected to inner part of brain via ventricular system

43

Neurologic Systems (6):

1. Ventricular
2. Vascular
3. Neurochemical systems
4. Consciousness system
5. Motor system
6. Sensory system

44

Ventricular Neurologic System:

Also called Cerebrospinal system

Ventricles are cavities filled with CSF (cushions brain) produced by choroid plexuses (structures in each ventricle)

Consist mainly of - paired lateral ventricles in each hemisphere, third ventricle between the 2 thalami & 4th ventricle

45

Vascular Neurologic System:

Involves blood vessels-provides oxygen and nutrients to structures & removes waste.

Brain receives blood from 2 arterial systems, carotid and vertebral basilar system These join at Circle of Willis at base of brain. Vascular disturbances can cause motor speech disorders

46

Neurochemical systems:

Influences all anatomic levels of nervous system.

Includes amino acids, ACH, neuropeptides, etc.

47

Consciousness system:

Important for maintaining consciousness, attention & awareness of environment.

Structures involved in this level include those found at supratentorial & posterior fossae level.

Damage can result in motor speech disorders.

48

Motor system:

Responsible for all motor activity including that of speech.

Includes efferent connection to cortex, basal ganglia, cerebellum, CNS/PNS pathways.

Damage here can cause motor speech disorders.

49

Sensory system:

Includes peripheral receptor organs

50

Structural elements of Neurons

1. Dendrites
2. Axons
3. Cell body (soma)

51

Dendrites:

Transmit sensory information toward the soma

52

Axons:

Transmit information away from the soma

Axons end in synapses which release neurotransmitters

Axons = collection of many nerve fibers

53

Most important neurotranmitter for muscles contraction?

AcH
Release of AcH results in contraction of muscle fiber

54

Nerves:

Groups of fibers traveling together in PNS

55

Where are cell bodies located?

Cell bodies stay in CNS

56

Where do nerves travel?

Between cell bodies and peripheral end organ to be innervated

57

In CNS, groups of fibers are called:

pathways or tracts

58

Where are impulses carried to in the CNS?

pathways/tracts carry impulses to other neurons

59

Where are impulses carried to in the PNS?

impulse is carried to the end organs

60

Motor Unit:

Made up of the axon and the muscle fiber it innervates

61

Supporting (Glial) Cells (3):

1. Oligdendroglia cells-form myelin in CNS
2. Schwann cells – form myelin in PNS. (between myelin in both are spaces called Nodes of Ranvier.)
3. Astrocytes- found in CNS –help move substances between blood and neurons of CNS – part of blood-brain barrier that keeps toxins from brain.

62

Oligdendroglia cells (type of glial cell):

form myelin in CNS

63

Schwann cells (type of glial cell):

form myelin in PNS

64

Spaces between myelin in CNS and PNS:

Nodes of Ranvier

65

Astrocytes (type of glial cell):

found in CNS

help move substances between blood and neurons of CNS – part of blood-brain barrier that keeps toxins from brain

66

How can a neuron be damaged?

lack of oxygen (ischemia) caused by disruption in blood supply

67

When axons are separated from cell body it causes...

motor speech problems

68

If lower motor neuron innervation to muscle is lost...

muscle will atrophy

69

What are some pathological reactions to neurons, axons, myelin, and lower motor neurons (5)?

1. Neuron can be damaged due to lack of oxygen (ischemia) caused by disruption in blood supply.

2. Axons may be separated from cell body resulting in motor speech problems.
3. If lower motor neuron innervation to muscle is lost – muscle will atrophy.

4. Myelin can shrink due to injuries

5. Certain diseases attack myelin, i.e. multiple sclerosis & Guillain Barre dz. Causes demyelination

70

Thalamus:

Paired structures deep inside brain

Acts as relay station

Helps to mediate speech, language & cognitive function

Also integral part of motor control system

71

Basal Ganglia:

Located deep inside cerebrum

Consists of # of related structures

Important part of motor speech system

72

Parts of the Basal Ganglia:

* Globus Pallidus
* Striatum
-Putamen
-Caudate Nucleus
* Lentiform nucleus – composed of globus pallidus & putamen

73

Substantia Nigra & Subthalamic Nuclei:

Important in motor control & work with basal ganglia.

Similar in structure & function to basal ganglia. (Sometimes substantia nigra may be considered part of basal ganglia.)

Located primarily in midbrain

Important in motor control – works with basal ganglia.

74

Reticular formation:

Part of brain stem

Important in motor control

75

Localization of Neurological Lesions:

Damage can be:

1. Focal – found in single area.

2. Multifocal – found in more than one area.

3. Diffuse – involve bilateral symmetric parts of nervous system, such as dementia, where there is generalized cerebral atrophy

76

Etiologies capable of producing Motor Speech Disorders (6):

1. Degenerative diseases-gradual decline in neuronal function.

2. Inflammatory diseases-Meningitis

3. Toxic-metabolic diseases-due to vitamin deficiencies, drug toxicity.

4. Neoplastic dz – tumors.

5. Traumatic injuries – gunshot, car accidents, falls, etc.

6. Vascular diseases – CVA most common. Neurons deprived of oxygen due to disruption in blood supply. CVA results in focal lesions and is acute.

77

Motor Unit:

Consist of motor neuron and muscle fibers innervated by the motor neuron.

78

Lower Motor Neurons:

Motor nuclei through which CNS sends impulses to muscles (and glands).

Motor neurons involved in motor movement & originate in brain stem or spinal cord from a cranial or spinal nerve

Axons of these neurons leave cell bodies & travel to specific muscles. Axons subdivide into branches that connect with muscles fibers

79

Inproper innervation of muscles can result in (2):

-muscle atrophies (withers)
-fasiculations.

80

How can an axon innervate several muscles fibers?

it splits into branches

81

Do muscles fibers receive information from just 1 motor neuron?

No.

Each fiber may receive input from branches of different motor neurons

82

Upper Motor Neurons:

Cell bodies in motor cortex and their descending axonal processes that synapse on cranial and spinal motor neurons

Originate in upper brain levels

83

4 main parts to speech motor system:

1. Final Common Pathway
2. Direct Activation Pathway
3. Indirect Activation Pathway
4. Control Circuits

*The organization of the speech motor system emphasizes motor (efferent) pathways, however sensory (afferent) pathways are important also and problems in sensory pathways can impact motor function

84

Final Common Pathway of the Speech Motor System:

Also called Lower Motor Neuron system or PNS.

Called Final Common Pathway because it’s the last link in sequence of motor events that lead to motor movement & all other components have to go through it.

Includes:
-12 paired cranial nerves
-31 paired spinal nerves

85

Muscles Innervation can be (4)

1. Bilateral
2. Unilateral

And:
1. Contralateral
2. Ipsilateral

86

Bilateral Muscle Innervation:

Receives innervation from both sides

Protective function for most of cranial nerves

If one side is damaged, the other side may stay intact.

Provides protection for important functions.

87

Unilateral Muscle Innervation:

Receives innervation from only 1 side

Damage occurs more easily than with bilateral innervation

88

Contralateral Muscle Innervation:

Receives innervation from opposite side

89

Ipsilateral Muscle Innervation:

Receives innervation from same side

90

For most nerves equal innervation comes from...

opposite (both) sides of the cortex

91

Does Cranial Nerve VII (facial nerve) have bilateral or contralateral innervation?

Both!

-bilateral innervation for upper face
-contralateral, unilateral innervation for lower face

92

How is Cranial Nerve XII (hyproglassal) innervated?

-Bilateral to most tongue muscles
-Contralateral innervation to genioglossus

93

Where can lesions (damage) to nerves occur?

either UMN or LMN

94

Damage to LMN system results in:

1. weakness
2. atrophy
3. fasiculations

95

Cranial Nerve V (Trigeminal Nerve):

-Bilateral Innervation

-Largest of cranial nerves

-Sensory from face, mouth, jaw, tongue.

-Motor to muscles of mastication, tensor tympani (middle ear, tenses the tympanic membrane), tensor veli palatini (tenses soft palate), mylohyoid (extrinsic laryngeal muscle involved in moving larynx)

96

Bilateral lesions to Cranial Nerve V (Trigeminal Nerve) (a LMN) result in:

-Jaw may hang open at rest
-Can have profound effect on speech

97

Unilateral lesions to Cranial Nerve V (Trigeminal Nerve) (a LMN):

-Jaw deviates to weak side ALWAYS
- Does not affect speech too much

98

Cranial Nerve VII (Facial Nerve):

-Innervates muscles of facial expression

-Bilateral innervation – to upper face - so if patient can’t wrinkle forehead, there are probably 2 lesions.

-Contralateral– to lower part of face

99

Cranial Nerve IX (Glossopharyngeal Nerve):

-Innervates stylopharyngeus muscle of pharynx (elevates pharynx in speech & swallowing).

-Sends sensory information from pharynx, tongue and Eustachian tube.

-Lesions cause reduced pharyngeal sensation & decrease in gag reflex.

-Bilateral innervation

100

3 Branches of Cranial Nerve X (Vagus Nerve):

1. Pharyngeal branch

2. Superior laryngeal branch

3. Recurrent laryngeal nerve

*Bilateral innervation for all branches

101

Pharyngeal branch of the Vagus Nerve (CN X):

Innervates muscles of pharynx (except stylopharyngeus – IX) and soft palate (except tensor veli palatini-Vth) , also palatoglossus muscle of tongue

Responsible for elevating & pulling back the velum in VP closure in speech & swallowing. (Levator palatini – one of the main muscles which elevates soft palate.)
(Cranial nerve IX assists the pharyngeal branch in this.)

102

Superior laryngeal branch of the Vagus Nerve (CN X):

Innervates pharyngeal constrictor and cricothyroid (intrinsic laryngeal muscle – changes pitch through tensing vocal folds)

103

Recurrent Laryngeal Nerve branch of the Vagus Nerve (CN X):

Innervates other intrinsic laryngeal muscles
i.e. lateral cricoarytenoid, interarytenoids and posterior cricoarytenoid, thyroarytenoid

104

Cranial Nerve XI ((Spinal) Accessory Nerve):

-Head and neck movement

-Intermingles with Vagus and contributes to innervation of levator palatini (elevates soft palate) and somewhat to intrinsic laryngeal muscles

-Bilateral innervation

105

Cranial Nerve XII (Hypoglossal Nerve):

-Innervates all intrinsic tongue muscles and all extrinsic tongue muscles except palatoglossus (innervated by Xth)

-Innervation is bilateral to all tongue muscles, except genioglossus

-Damage can cause atrophy, weakness & fasiculations on tongue (LMN).
-UMN lesion – tongue deviates to side contralateral to lesion
-LMN lesion – tongue deviates to same side of lesion

106

When unilateral lesions occur, why does the structure (tongue, jaw, etc.) deviate to the side of weakness?

Because normal muscle contraction occurs on the strong (normal) side and no or little contraction occurs on the weak side
There is nothing to counteract the action of the muscle on the normal side
This results in the tongue, jaw, etc. being pushed to the weak side

107

If the unilateral lesion is UMN, the structure deviates...

contralateral to the side of the lesion

108

If the unilateral lesion is LMN, the structure deviates...

ipsilateral to the side of the lesion

109

If the lesion is bilateral, the result is...

decreased ROM and decreased strength

110

Spinal Nerves innervate...

muscles of respiration, including the phrenic nerve which innervates the diaphragm

111

Direct Activation Pathway (Pyramidal Tract):

-Directly connects and influences the FCP/LMN

-Along with the Indirect Activation Pathway, makes up the UMN system

-UMN system includes neurons that regulate the LMNs

112

2 tracts that make up part of the Upper Motor Neuron System and Direct Activation Pathway:

1. Coricobulbar
2. Corticospinal

113

Corticobulbar Tract:

-Most important for speech - involves the cranial nerves important for speech

-Originates in cortex (mainly at the primary motor cortex) and terminates in brainstem at the level of the cranial nerve nuclei involved with speech

-Called corticobulbar because “bulb” refers to brainstem, where the axons terminate

114

Corticospinal Tract:

-Originates in cortex and descends to lower medulla where it terminates at the level of the spinal nerve nuclei

115

Where do the Corticobulbar and Corticospinal tracts descend form?

Both tracts descend from cortex (primarily motor cortex of both hemispheres, also from premotor cortex and Supplemental Motor area) through corona radiata and internal capsule to brainstem.

The corticospinal tract continues on to the spinal cord.

116

The Direct Activation Pathway is important for...

controlled skilled, discrete and often rapid voluntary movements as is seen in speech

117

Do unilateral LMN lesions have a severe impact on speech?

Yes

118

Do unilateral UMN lesions have a severe impact on speech?

No.
Because there is still innervation from the other side

119

Do bilateral UMN lesions have a severe impact on speech?

Yes

120

Where does weakness occur when UMN lesions is unilateral?

Typically on the opposite side of the body (contralateral)

121

Indirect Activation Pathway (Extrapyramidal Pathway):

-Part of the UMN system along with the Direct Activation Pathway.

-Is less understood and its function is difficult to separate from basal ganglia and cerebellum

-Does influence directly the LMN system whereas the basal ganglia and cerebellum do not

-Starts in motor cortex and has various synapses before arriving at brainstem

-The DAP is analogous to a direct or express train line with no stops. Whereas the IAP is like a local line stopping at various places

-The IAP is made up of several short paths and interconnected structures between the origin in the cortex and its final termination at the cranial nerve nuclei and spinal cord nuclei (corticorecticular, etc.)

122

Reticular formation:

Scattered cells in the brainstem that is important in sensorimotor integration

123

Control Circuits (function):

Integrate or help control the structures and pathways involved in motor movement

Have no direct contact with LMNs

124

Control Circuits (2):

1. Basal Ganglia
2. Cerebellum

125

Basal Ganglia Control Circuit:

-Depends on balance among several neurotransmitters (AcH, dopamine, and GABA (gamma-aminobutyric acid) for aiding motor activity.

-Provides input to cerebral cortex to coordinate motor movement.

-Involved in regulating muscle tone & maintaining normal posture.

126

Damage to the Basal Ganglia Control Circuit:

Can result in Hypokinetic dysarthria or Hyperkinetic dysarthria

127

Cerebellar Control Circuit:

Integrates and coordinates movements for speech, including timing, size of muscular action and sequences of movements to provide smoothly flowing well-timed, coordinated speech

128

Damage to the Cerebellar Control Circuit:

ataxic dysarthria