Localization Flashcards

1
Q

Upper Motor Neuron Lesion

A

Location: Descending from brain (cortex) to spinal cord (synapse 1 at cell body of anterior horn)

  • weakness: Extensors of upper extremities; Flexors of lower extremities
  • spastic paralysis: Especially Flexors of upper extremities, and Extensors of LE
  • increased reflexes
  • increased tone
  • difficulties with fine motor control
  • positive Babinski reflex
  • positive clasp knife spasticity
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2
Q

Lower Motor Neuron Lesion

A

Location: PNS (leaving the spinal cord to synapse at the NMJ)

  • weakness: follows distribution of the motor unit
  • atrophy
  • fasciculations: simultaneous discharge of whole motor unit
  • Fibrillations: spontaneous contraction of a single muscle fiber
  • decreased reflexes and tone
  • flaccid paralysis
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3
Q

Primary Sensory Cortex

A
  • Post-Central Gyrus (Parietal Lobe)

- Brodmann areas 3, 1 and 2

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4
Q

Primary Motor Cortex

A
  • Pre-Central Gyrus (Frontal Lobe)

- Brodmann area 4

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5
Q

Lateral Corticospinal Tract

A

Function: Descending voluntary movement of contralateral limbs

1st Order Neuron: Motor cortex descends through the internal capsule, then decussates at the CAUDAL/LOWER MEDULLA (PYRAMIDAL DECUSSATION); descends contra laterally

Synapse 1: Cell body of the anterior horn

2nd Order Neuron: leaves spinal cord
Synpase 2: NMJ

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6
Q

Bell’s Palsy vs. LMN Lesion vs. UMN Lesion

A

Bell’s Palsy: Complete destruction of Cranial Nerve VII: The whole face loses tone

LMN Lesion: Ipsilateral paralysis of upper and lower face

UMN Lesion: Lesion occurs between the motor cortex and the facial nucleus

  • Only CONTRALATERAL paralysis of LOWER FACE
  • Forehead is spared due to bilateral UMN innervation
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7
Q

Myotomes

  • Diaphragm
  • Deltoid
  • Tricep
A
  • the muscles that are innervated by specific spinal cord roots
  • Diaphragm: C3, C4 and C5
  • Deltoid: C5
  • Tricep: C7
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8
Q

Dermatomes

  • Thumb, Digits 1&2
  • Medial Hand
  • Big toe
  • Heel
A
  • sensory areas that tell you what segment of the spinal cord is effected
  • Thumb, Digits 1&2: C6
  • Medial Hand/pinky: C8
  • Big toe: L5
  • Lateral foot/Heel: S1
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9
Q

Deep Tendon Reflexes

  • Biceps
  • Triceps
A
  • Biceps: C5

- Triceps: C7

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10
Q

Pronator Drift Test

A
  • Hold arms out and close eyes

- Positive test: One arm drifts down and pronates; indicates UMN Cortical Spinal Tract Lesion

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11
Q

Dorsal Column/Medial Lemniscal Pathway

A

Function: Ascending

  • Pressure
  • Vibration
  • Fine Touch
  • Propioception

1st Order Neuron: Cell body in Dorsal Root Ganglion enters spinal cord and ascends ipsilaterally in Dorsal Column

Synapse 1: Medulla (Ipsilateral Nucleus cuneatus or gracilis)

2nd Order neuron: Decussates in medulla, ascends contralaterally to the medial lemniscus

Synpase 2: VPL Thalamus

3rd Order: Sensory Cortex

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12
Q

Spinothalamic Tract

A

Lateral: Pain & Temperature
Anterior: Crude Touch & Pressure

1st Order: Sensory nerve endings/Cell body in Dorsal root ganglion enters the spinal cord

Synapse 1: Ipsilateral gray matter in spinal cord

2nd Order: Decussation at anterior white commissure, ascending contra laterally

Synapse 2: VPL Thalamus

3rd Order: Sensory Cortex

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13
Q

VPL (ventroposterior lateral) nucleus

A

receives sensory information from your body

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14
Q

VPM – ventroposterior medial nucleus

A

receives sensory information from your face

- Is more Superior to the VPL; facial sensory information crosses at level above High Pons

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15
Q

LGN (Lateral geniculate nucleus)

A

receives visual/optical information

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16
Q

medial geniculate nucleus:

A

receives hearing

17
Q

Frontal Lobe

A
  • motor control
  • executive functions (initiating, planning, self-check, ability to pay attention)
  • Broca’s area (in dominant hemisphere): Motor speech

Lesion:

  • IPSILATERAL GAZE
  • Aphasia if in dominant (usually left) hemis
  • inattention
  • contralateral weakness
  • perseveration: repetition of words or phrases
18
Q

Parietal Lobe

A
  • the sensory lobe.
  • Position in space, proprioception, having a sense of direction, sensory command

Lesion:

  • Hemineglect (Contralateral): Lesion in non-dominant (usually right) side
  • anesthesia
  • thermalgesia
  • apraxia
  • graphasthesia
  • asterognosia
19
Q

Temporal Lobe

A
  • Primary Auditory cortex
  • Wernicke’s Area (dominant hemisphere): receptive language
  • Memory (episodic-lifetime, academic-semantic)

Lesion:

  • central deafness
  • receptive aphasia
  • amnesia
20
Q

Occipital Lobe

A
  • Principal visual cortex (BRODMANN AREA 17)

Lesion:

  • dyslexia
  • contralateral hemianopia
  • impaired recognition of colors
21
Q

Fasciculus Cuneatus

A

Dorsal column pathway for upper body and upper extremities

22
Q

Fasciculus Gracilis

A

Dorsal column pathway for lower body and lower extremities

23
Q

Brown-Sequard Syndrome

A

Hemisection of spinal cord:

  • Ipsilateral UMN signs/Corticospinal tract
  • Ipsilateral dorsal column damage (tactile, vibration, propioception sense)
  • Contralateral spinal thalamic damage (Pain & temp)
24
Q

Syringomyelia

A
  • Syrinx at central spinal cord epands and damages the anterior white commissure of the spinothalamic tract
  • Results in bilateral, CAPE-LIKE distribution loss of pain and temperature sensation
  • Usually at level of C8-T1
25
Q

Sensory Symptoms at level of Brainstem / Thalamus

A

Lesion at Thalamus: all sensory modalities are affected contra laterally

Lesion above High Pons:
- Contralateral sensory deficits for face/arms/legs

Lesion Below Mid Pons:

  • Ipsilateral sensory deficits of face (sensory fibers have not yet crossed)
  • Contralateral sensory deficits of arms/legs
26
Q

Anterior Cerebral Artery

A
  • Perfuse the motor and sensory cortex of the LOWER LIMBS
27
Q

Middle Cerebral Artery

A
  • Perfuses the Motor and sensory cortex of the UPPER LIMB and FACE
  • Pefuses the temporal (Wernicke’s area) and frontal lobe (Broca’s area)
28
Q

Internal Carotid Artery

A
  • gives distribution of both the ACA and MCA, feeding the motor/sensory cortex of both upper and lower limbs
29
Q
  • Paresis
A

= WEAKNESS

30
Q
  • Plegia
A

= PARALYSIS

31
Q

Location of Cranial Nerve Nuclei in Brainstem

A

From Cranial to Caudal:

  • Mesencephalon: CNs 3 and 4
  • Middle Pons: CN 5
  • Pontomedullary junction: CNs 6, 7, 8
  • Upper medulla: CNs 9 and 10
  • Lower medulla: CN12
32
Q

Location of Long Tracts in Brainstem

A

Ventral to Dorsal:

  • Pyramidal (motor): ventral
  • Medial lemniscus (Propiosensory): central
  • Spinocerebellar: dorsolateral
  • Spinothalamic: Lateral
  • Medial longitudinal fascicle: centrodorsal
  • Sympathetic tract: dorsolateral
33
Q

Oculosympathetic Pathway

A

An Uncrossed Pathway:

  • Primary: Hypothalamus
  • Secondary: Intermediolateral column of spinal cord (T1 level)
  • Tertiary: Superior cervical (sympathetic) ganglion to the pupil, eylids and face
34
Q

Horner’s Syndrome

A
  • Associated with lesion of spianl cord above T1
  • Sympathectomy of face: PAM is Horny: (everything is ipsilateral)
    1. Ptosis: slight dropping of eyelid
    2. Anhidrosis: absence of sweating and flushing
    3. Miosis: Pupil constriction
35
Q

Referred Pain

A
  • Pain felt at a distance
  • Usually PROXIMAL
  • NOT ASSOCIATED WITH DERMATOMES

Upper lumbar area: pain refers to flank, groin, or anterior thigh

Lower lumbar area: pain refers to buttocks and posterior thigh

36
Q

Radicular Pain

A
  • problem associated with spinal nerve root (e.g., impingement)
  • DISTAL PAIN
  • DERMATOMAL
  • with positive straight leg raise sign
37
Q

Most Sensitive Test to Diagnose Radiculopathy

A

Electromyography (EMG): inlcudes nerve conduction studies

  • localizes lesion to the root, plexus or nerve
  • shows extent of nerve root involvement
38
Q

Cauda Equina Syndrome

A
  • Loss of function of at least 2 of 18 nerve roots from L2 and below
  • deficits are BILATERAL but ASYMMETRIC
  • Presents with lower back pain radiating to legs, weakness, sensory loss, bladder/sphincter paralysis