Somatic Motor

Sensory

of cranial and spinal nerves arising from neurons whose cell bodies are located within the brainstem and spinal cord or lie in dorsal root ganglia.

when affects:

• cell body of the alpha motor neuron located within the SC or BS
• axons that arise from the ant. horn cell that form spinal and peripheral N.'s and cranial N.'s
• Motor endplate of the axon
• Mus. fibers innervated by the motor N. axon

Endoneurium

Perineurium

Epineurium

envelopes groups, or fascicles, of axons

responsible for maintaining the blood-nerve barrier

outer most layer

surrounds entire nerve and provides cushioning for the entire nerve

Becomes fibrosed with increased collagen

fibers controlling motion are more affected during aging?

more than the fibers controlling sensation

axonal degeneration that occurs distal to the lesion

begins immediately after involvement

more severe

• Affects the axon cell body
• axonal degeneration
• the longest nerve fibers are typically affected first
• S&S beginning distally and spreading proximally as the dz progresses

will affect feet and lower legs first because nerves in legs are longer

before hands and fingers

• conditions that affect only myelin in both sensory and motor fibers
• disruption of the conduction of the action potential from proprioceptors and neuropathies causes sensory changes

• segmental demyelination
• slows or blocks conduction of the AP at the point of demyelination of a myelinated nerve.
• often occurs after nerve compression that induces mild ischemia in the fibers.

• segmental demyelination occurs because of dz.
• conduction is normal above and below compression
• axon remains intact preventing mus. atrophy

• Axon has been damaged but the connective tis coverings that support and protect the nerve remain intact.
• prolonged compression causes infarction and necrosis

most severe axonal loss

complete severance of the axon as well as the disruption of its supporting connective tissue coverings

gun shot, stab wounds, or avulsions

•                 for regeneration after axonal/wallerian degeneration is possible as long as the nerve cell body remains viable.
• new axons can sprout from proximal end of damaged axons
• occurs best in axonotmesis because connective tissue coverings remain intact
• less so in neurotmesis unless surgically fixed

• if not surgically fixed axonal sprouts often enter nearby soft tis and form a neuroma, or axonal regrowth occurs down the incorrect endoneurial tube, rendering reinnervation
• non functional

single peripherial nerve affected

commonly results of trauma

ex. Carpal tunnel

• rate of onset
• type
• size of nerve fibers involved

involvement of several peripheral nerves

ex: Diabetic pt's

motor endplate or mus itself involved in peripherial ds

proximal weakness, wasting, and hypotonia without sensory impairments

spinal nerve or dorsal root ganglia (cell body) has been affected

this follows a ?

weakness occurs in all the muscles recieving axons from that spinal level

myotomal pattern.

• tingling
• prickling
• burning
• band like dyestesias and paresthesias in feet

• dying back of the longest fibers in all nerves from distal to proximal
• > than one nerve involved= polyneuropathy

hypotonicity

 flaccidity

Pt asked to walk on their heels or toes (dorsiflexors or plantarflexors are proven weak)

 DTR's (deeptendon reflex) are diminished or absent

Hereditary Motor and Sensory Neuropathy(HMSN)

Peroneal Muscular Atrophy

Fibular N affected and muscles of the foot and lower leg

then eventually to hands and feet

slow progressing

Most common

onset is in childhood

most common

Mutations in proteins associated with Schwann Cell myelination

Creates extensive demyelination and hypertrophic onion bulb formation in which demyelinated axons are surrouned by schwann cells and their processes as remyelination is attempted

is an adult onset ds

between 2nd and 7th decades

less involvement in the small mus. of the hands

• Symptoms are not all or none but graded
• Differing degrees of signs and symptoms among family members who have INHERITED the defective gene

Pt will appear with symmetrical mus weakness, atrophy, and diminished DTR's

• PES CAVUS
• HAMMER TOES
• Weak dorsiflexors and evertors
• Ambulate w/ footdrop (steppage gait pattern)
• Then intrinsics of the UE to the FA mus.

• demyelinates peripheral nerves
• proprioception is lost in feet and ankles
• cutaneous sensation is diminished in the foot and lower legs

Less sensory loss

symptoms could be:

• tingling
• burning in the feet and legs
• impaired proprioception

• muscle wasting below the knee
• pt's legs take on the shape of and inverted champagne bottle
• normal mus. bulk above the knee

• orthotic devices can be used
• For foot drop and hand deformities
• caution should be taken to prevent ulcerations
• due to the lack of tactile sensation and propriocetion
• ROM to prevent contractures

Chronic neural compression (median nerve)

affecting sensation and motor function

will have

• pain
• tingling
• numbness
• paresthesia

can be anything that will decrease its volume of the carpal tunnel

or sustained rise in pressure with in the tunnel:

• synovial proliferation in RA
• Edema from local or systemic infections
• congestive heart failure
• pregnancy
• Callus formation after fx or malalignment
• tumors

• Normal is 7-8 mm Hg
• With this ds pressure rises up to 30mm Hg when wrist flexion or extension occurs
• Can go as high as 90 mmHg when fully flexed
• Causing ischemia in the nerve and then will see nocturnal symptoms

• Can radiate to FA, shoulder, and neck
• nocturnal pn is the Hallmark
• Sensory symptoms usually precede motor

:used to replicate CTS symptoms

• Phalen's test: wrist flexed 90 degrees for 1 min
• Tinel's test: wrist percussion over tunnel
• Carpal compression: pressure applied over flexor retinaculum
• Pt usually has a positive flick sign

• lumbosacral radiculopathy
• may occur in the presence of abcess, blood clots, or tumors
• herniation of the intervertebral disk can impinge on the nerve root

• Coughing, sneezing, or sitting worsens the pain
• L4-L5 and S1
• can radiated down 1 or both legs
• pressure neuritis- irritation of the nerve

Cranial Nerve VII (facial)

Unilateral

Ages 15-45

cause not known

• diabetic pt
• pregnant
• latent herpes virus/ herpes zoster

Early signs: days before

• may recall severe pn in the area of the mastoid or a sensation of fullness in the ear

• lies in auditory canal
• so any inflammation and swelling will create a compression that initially causes demyelination
• innervates stapedius mus of the middle ear
• sensory and autonomic fibers, which innervate for taste and lacrimation and salivation
• loss of taste on affected side
• less but thicker saliva
• autonomic fibers= cause dry eye (lack of tearing)
• Sometimes sounds are louder than normal

With         involvement of the facial nerve the pt can close the eye and wrinkle the forhead but cannot smile voluntarily.

With         involvement the pt is unable to close the eye, wrinkle forhead, or smile voluntarily.

• Given for 5 days then tapered dose for 5 days to Bell's Palsy pt's
• Most have a complete recovery within weeks but can take longer
• pt's with DM, HTN, and symptoms of a lesion with autonomic involvement might not either make full recovery or take a lot longer

• comes off the lower part of the brachial plexus
• from C8-T1 nerve roots
• passes behind medial epicondyle
• then through the two heads of the flexor carpi ulnaris through FA to wrist
• crosses flexor retinaculum and divides into a superficial and deep branch in the hand

• secondary to fractures in the elbow
• occurs years after a fx due to callus formation or a valgus deformity
• produces gradual stretching of the nerve in the ulnar groove of the medial epi

• will see claw hand deformity
• MCP ext and IP flexion of ring and little finger
• unopposed action of the extensor mus group and paralysis of the 3rd and 4th lumbricals that normally flex MCP's and extend IP's

• Flat hypothenar
• weak little pinky abductions
• palmaris brevis and abductor digiti minimi
• Dorsal interossei
• Paralysis of the FCU produces a radial deviation of the hand when wrist flex is attempted

• Mod and severe require surgery to relieve compression
• medial epiconlylectomy
• transposition of the ulnar n. to anterior aspect of the elbow
• Claw hand should be treated with a splint that blocks MCP hyperext.

• entrapment syndrome caused by pressure from structures in the thoracic outlet on fibers of the bracial plexus at some point between interscalene triangle and inferior border of the axilla
• Vascular symptoms because of pressure on subclavian

Divided into 3 categories:

1. neurogenic= compression of brachial plexus
2. vascular= compression of subclavian artery/or vein
3. disputed= nonspecific TOS w/ chronic pn and symptoms of brachial plexus

• axons are preserved but segmental demyelination occurs.
• after loss of myelin the axons are more vulnerable to unrelieved compression

• neuropraxia can lead to this
• in which axon continuity is lost and wallerian degeneration occurs.

•                                of nerve roots or proximal plexus and arteries between the clavicle and 1st rib or impinging mus. causing edema and ischemia in the nerves
• creating a Neurapraxia----> to a axonotmesis

pt reports paresthesias and pain in the arm,

most often nocturnal

pain, tingling, and paresis

• Pain is reported in the neck
• this may radiate into the face (sometimes ear pain)
• and anterior chest as well as over scapulae
• also extend over the lateral aspect of the FA into the hand

• symptoms extend over lateral aspect of the FA into the hand.
• If the lower plexus is compromised pain and numbness occur in the posterior neck and shoulder, medial arm, and FA
• then going into the ulnarly innervated digits of the hand

• also include:
• coldness
• edema in the hand or arm
• Raynauds Phenomenon (cyanosis)
• fatigue in hand and arm
• superficial vein distention in hand

• Usually relates to posture and activites that aggravate symptoms
• overhead and lifting activies, along with mvm of the head, produce symptoms in the upper plexus

used to elicit symptoms of TOS, but these test have a high false positive response.

Or alcoholic neuropathy

a demonstrable ds, either clinically evident or subclinical, that occurs in the setting of DM without other causes for peripheral neurophathy

• Also known as Acute inflammatory demyelinating polyradiculoneuropathy (AIDP)
• Immune- mediated ds
• bacterial (campylobacter jejuni) (found in uncooked foods)
• Viral (Haemophilus influenza, Epstein- Barr virus, CMV) infections, SX, Vaccinations, ALL ASSOCIATED with developement of GBS

• 2/3 people report an acute infection within 2 months after onset
• 90% had illnesses (respiratory or gastrointestinal)after 30 days Acute= is the traditional form

heterogenous forms= associated with

c. jejuni = is more common with axonal form

 CMV = more common with greater sensory involvement

•  generalized inflammatory response
• Lymphocytes (Tcells) and macrophages are the inflammatory cells present
• Demyelination, intiated at the Node of Ranvier because macrophages responding to inflam. signals then strip myellin from the nerves

• Varicella-zoster virus (VZV) is a common herpes virus that affects the nervous system.
• common virus that causes chicken pox in children
• this lies dormant with in sensory ganglia of cranial and spinal nerves and can become activated later in life to cause (HZ), or shingles
• Immunocompromised are at risk

• Inflammation produces pn and tingling in the involved dermatome with a rash followed by developement of vesicles (blisters) that burst and encrust in the same dermatome
• Thoracic and trigeminal dermatomes are most often involved

• Occasionally, the inflammation may affect motor neurons and produce LMN S&S and then is lingering for weeks to months
• its very painful and has been described as a constant aching, burning, cutting, or stabbing pn

• also called Tic Douloureux
• ds of the trigeminal nerve V
• there are intense paroxysms of lancinating pn within the nerve's distribution
• thought to be caused by herpes zoster, MS, vascular lesions, or tumor = anything that can affect the nerve to produce painful sensation

• Typically in women
• age 50-70
• not common ds
• Idiopathic
• its a painful sensation to the nerve (unrelenting)
• restricted to the Maxilla, Mandibular divisions together and also the ophthalmic division

• any mechanical stimuli :
• chewing, smiling, or even a breeze can trigger attack
• often occurs in clusters
• attacks become more frequent over the course of the ds

• when medications are not working
• a radio frequency rhizotomy is preferred over trigeminal nerve section or alcohol ablation
• Microvascular sx is also used when small blood vessels have be found to constrict the trigeminal n. near its root

• motor endplate ds
• most common of the ds of neuromuscular transmission
• fluctuating weakness and fatigability of skeletal mus.

• autoimmunes ds
• related to thymic ds: hyperthyroidism, thyrotoxicosis, thymic tumor
• DM, RA, Lupus as well
• Exacerbations may occur before menstrual period or shortly after pregnancy

• The number of ACh receptors are decreased and those that remain are flattened, results in decreased efficiency of the neuromuscular transmission
• 75% of pts have abnormalities of the thymus (removing thymus will have a good outcome)

• 80% of people
• can be ocular mus affected or
• more generalized patterns with proximal mus weakness in the limb musculature

• Cranial mus particularly eyelids and mus controlling eye mvm are first to show weakness
• Diplopia
• ptosis (drooping eyelids)- commonly causing pt to tilt head bak to see
• Weak neck mus may cause head bobbing
• Chewing meat produces fatigue
• facial expression- snarling because lip does not close
• speech is more nasal
• Dif swallowing-result of palatal, pharyngeal, and tongue weakness. Nasal regurgitation or aspiration of food is common

• Medical emergency
• respiratory muscle involvement
• Patient will be placed on a ventilator right away

• presynaptic ds of the neuromuscular junction that can cause symptoms similar to those of MG
• its a autoimmunine ds associated with neoplasm, most commly small cell (oat cell) carcinoma of the lung

Immunosuppression drugs such as corticosteroids

 taken usually before meals to be able to eat if dif chewing and swallowing

AChE inhitor meds provides improvement of weakness but does not treat the underlying ds

(GI problems such as N&V, abdominal cramping, increased secretions)

• variable course with remissions and exacerbations especially in the 1st year of onset
• symptoms flucuate during the day
• remissions are rarely complete or permenant
• Slowly progressive course

• 3x > woman
• Boys = Girls
• There is familial link
• recurrent attacks of HA, widely variable in intensity, frequency and duration.
• Attacks commonly unilateral
• associated with anorexia, N & V

there is dilation of the middle cerebral artery and superficial temporal  artery on pn. side

peptides are released causing THROBBING of the vessels

its the key component in the distribution of the pn with the head and neck associated with migraine

Aura comes before HA and reducing bloodflow by 20% causing hypoxia

Smoking

Chocolate

Aged Cheese

Red wine

Food additives

Pt wants to be left in the dark

Afters symptoms gone they feel heavy, with scalp tenderness

• Rare type
• most painful of the HA's
• Radiates behind 1 eye
• explosive feeling
• unrelenting sever pn
• Pt walking around in circles

Horners syndrome is related to this type of HA.

(droopy eyelid, and consticted pupil)

Or Forehead sweating

Appears on uninvolved side

• Chronic ds
• recurrent seizures- sudden usually unprovoked attacks of subjective experiential phenomena, altered awareness, involuntary mvm's, or convulsions
• one seizure does not imply this=could be brain dysfunction

Part of brain can be taken out

can be simple-     ?      -pt remains conscious, unilateral, with some jerking motion, and tingling

Complex- not a good prognosis

altered state of conscious

both hemispheres are involved

• absence seizure-pt unaware of
• sudden cessation of ongoing conscious activity with only minor convulsive muscular activity or loss of postural control
• could be talking, miss a few words, looking into space and then carry on conversation

• Grand mal Seizure
• Total loss of control and loss of consciousness= archetypal seizure
• falls on floor with rigid posture, clinch hands, cyanotic, might cry (tonic phase)
• then rapid jerking, saliva, frothing @ mouth, biting tongue (clonic phase)
• most pt's know when these will occur
•  they are on epileptic meds, could have sx
• Incontinence of B&B

• medical emergency
• condition in which seizures are so prolonged or so repeated that revocery does not occur between attacks.
• leading to death
• often result of tumor, CNS infection, or drug abuse

• Common cause of status epilepticus in children under age 3
• 9/10- babies found with infection to be cause (possib. ear) (high fever causes seizure)
• babies thermoregulatory sys is not fully developed yet- baby gets high fever and they cant feel the pain so body goes into seizure (comes 1st before pn)
• put on meds to regulate- may become hyperactive or lethargic