Cranial and peripheral nerve disorders

Question 1

Peripheral nerve disease/injury - Wallerian degeneration

Answer 1

transection results in degeneration of the axon and myelin sheath distal to the site of axonal interruption
Chromatolysis and repair processes occur in nerve cell body
Endoneurium (sheath) does not degenerate but forms a tube directing regeneration

Question 2

Peripheral nerve disease/injury - Segmental demyelination

Answer 2

axons are preserved (no wallerian degeneration)

remyelination restores function (like with GBS)

Question 3

Peripheral nerve disease/injury - axonal degeneration

Answer 3

degeneration of axon cylinder and myelin, progressing from distal to proximal, “dying back” of nerves (peripheral neuropathy)

Question 4

Peripheral nerve disease/injury - Neuropathy =

Answer 4

any disease of nerves characterized by deteriorating neural function

Question 5

Peripheral nerve disease/injury - neuropathy - polyneuropathy =

Answer 5

bilateral symmetrical invovlement of peripheral nerves, usually legs more than arms, distal segments earlier and more invovled than proximal

Question 6

Peripheral nerve disease/injury - neuropathy - mononeuropathy =

Answer 6

involvement of a single nerve

Question 7

Peripheral nerve disease/injury - radiculopathy =

Answer 7

involvement of nerve roots

Question 8

Peripheral nerve disease/injury - traumatic nerve injury - neurapraxia

Answer 8

Class 1
Injury to nerve that causes a transient loss of function (conduction block ischemia)
nerve dysfunction may be rapidly reversed or persist a few weeks
ex = compression

Question 9

Peripheral nerve disease/injury - traumatic nerve injury - axonotmesis

Answer 9

Class 2
Injury to nerve interrupting the axon and causing loss of function and wallerian degeneration distal to the lesion
with disruption of endoneurium (sheath), regeneration is possible
ex = crush injury

Question 10

Peripheral nerve disease/injury - traumatic nerve injury - neurotmesis

Answer 10

Class 3
Cutting of nerve with severance of all structures and complete loss of function
Reinnervation typically fails without surgical intervention because of aberrant regeneration (failure of regenerating axon to find its terminal end)

Question 11

Peripheral nerve disease/injury - clinical sx of LMN syndrome

Answer 11

Weakness/paresis
Hyporeflexia
Hypotonia
Atrophy
Fatigue
Sensory loss corresponding to motor weakness
Autonomic dysfunction (VD, dryness, warm skin, edema, OH)
Sensory dysesthesias, motor fasciculations/spasms
Muscle pain

Question 12

Trigeminal neuralgia - etiology

Answer 12

results from degeneration or compression
occurs in people over 50
abrupt onset

Question 13

Trigeminal neuralgia - characteristics

Answer 13

brief paroxysms of neurogenic pain (stabbing and/or shooting) pain; reocurring frequently
Occurs along distribution of trigeminal nerve (mostly mandibular and maxillary)
Restricted to one side of the face

Question 14

Trigeminal neuralgia - tend to have ___ instability

Answer 14

autonomic

exacerbated by stress or cold, relieved with relaxation

Question 15

Bell’s Palsy - what is it

Answer 15

LMN involving facial nerve (7) - resulting in unilateral facial paralysis

Question 16

Bell’s Palsy - etiology

Answer 16

acute inflammatory process of unknown etiology (immune or viral disease) resulting in compression of the nerve within the temporal bone

Question 17

Bell’s Palsy - characteristics

Answer 17

Mm of facial expression on one side are weak or paralyzed
Loss of control of salivation or lacrimation
Onset is acute with max severity in hrs to days
Commonly preceeded with pain behind the ear
Most recover fully in wks to months

Question 18

Bulbar palsy refers to

Answer 18

weakness of paralysis of the mm innervated by the motor nuclei of the lower brainstem, affecting the muscles of the face, tongue, larynx, and pharynx

Question 19

Bulbar palsy - etiology

Answer 19

result of tumors, vascular degenerative diseases of lower cranial nerve motor nuclei

Question 20

Bulbar palsy - characteristics - voice quality

Answer 20

dysphonia - hoarseness, or nasal quality

Question 21

Bulbar palsy - characteristics - pseudobulbar palsy

Answer 21

bilateral dysfunction of corticobulbar innervation of brainstem nuclei; a central or UMN lesion analagous to coritcospinal lesions disrupting function of anterior horn cells

Question 22

GBS -

Answer 22

polyneuritis with progressive mm weakness that develops rapidly

Question 23

GBS - etiology

Answer 23

unknown

associated with an autoimmune attack, usually occurs after recovery from an infectious illness (resp or GI)

Question 24

GBS - characteristics

Answer 24

Acute demyelination of both cranial and peripheral nerves
Sensory loss, paresthesias (sensory loss less than motor usually)
Motor paresis or paralysis
Dysarthria, dysphagia, diplopia, facial weakness
Progression evolves over days or weeks and recovery is usually slow (6 m to 2 yrs)

Question 25

ALS

Answer 25

a degenerative disease affecting both UMNs and LMNs | Degeneration of anterior horn cells and descending corticobulbar and corticospinal tracts

Question 26

ALS - etiology

Answer 26

unknown (viral/autoimmune) | 5-10% genetic - autosomal dominant

Question 27

ALS - Characteristics -

Answer 27

``` Progressive - typically pass away within 2-5 yrs Bulbar onset (progressive bulbar palsy) or spinal cord onset (mm atrophy) UMN and LMN signs Dysarthria, dysphagia dysphonia USUALLY ABSENCE OF SENSORY CHANGES Autonomic dysfunction Pain Resp impairments Typical sparing of BB function Cognition typically normal ```

Question 28

Stages of ALS - stage 1

Answer 28

early disease mild focal weakness asymmetrical distribution symptoms of hand cramping and fasciculations

Question 29

Stages of ALS - stage 2

Answer 29

moderate weakness in groupd of muscles some wasting (atrophy) modified independence with assistive devices

Question 30

Stages of ALS - stage 3

Answer 30

severe weakness in specific muscles increasing fatigue mild to moderate functional limitations, ambulatory

Question 31

Stages of ALS - stage 4

Answer 31

Severe weakness and wasting of LEs Mild weakness of UEs Moderate assistance and assistive devices required Wheelchair user

Question 32

Stages of ALS - stage 5

Answer 32

progressive weakness wiht deterioration of mobility and endurance increased fatigue moderate to severe weakness of whole limbs and trunk spasticity hyperreflexia loss of head control max assist

Question 33

Stages of ALS - stage 6

Answer 33

bedridden dependent in ADLs progressive resp. distress

Question 34

Postpolio syndrome (PPS)

Answer 34

new. slowly progressive mm weakness occuring in individuals with a confirmed hisotry of acute poliomyelitis follows a stable period of functioning

Question 35

PPS - etiology

Answer 35

unknown | possible hyperfunctioning of motor neurons, long term over use at high levels resulting in new degeneration

Question 36

PPS - characteristics

Answer 36

new weakness and atrophy - asymmetrical in distribution abnormal fatigue pain slow progression, either steady or stepwise brain fatigue - difficulty with concentrating