UMN/LMN Lesion Characteristics

Question 1

Location of Lesion/Structures Involved: UMN

Answer 1

CNS:
- Cortex
- Brain stem
- Corticospinal tracts
- Spinal Cord

Question 2

Location of Lesion/Structures Involved: LMN

Answer 2

Cranial nerve nuclei/nerves
Spinal Cord: anterior horn cells, spinal roots
Peripheral nerves

Question 3

Diagnosis/Pathology Associated: UMN

Answer 3

Stroke
TBI
SCI

Question 4

Diagnosis/Pathology Associated: LMN

Answer 4

Polio
Guillain-Barre
Peripheral Nerve Injury
Peripheral Neuropathy
Radiculopathy

Question 5

Tone Characteristics: UMN

Answer 5

Increased: Hypertonia + Clonus

Velocity Dependent

Question 6

Tone Characteristics: LMN

Answer 6

Decreased or absent: Hypotonia, Flaccidity

Not Velocity Dependent

Question 7

Reflex Characteristics: UMN

Answer 7

Increased: Hyperreflexia

Exaggerated cutaneous and autonomic reflexes

+ Babinski

Question 8

Reflex Characteristics: LMN

Answer 8

Decrease or Absent: Hyporeflexia

Question 9

Associated Involuntary Movements: UMN

Answer 9

Muscle Spasms: Flexor or Extensor

Question 10

Associated Involuntary Movements: LMN

Answer 10

With Denervation: Fasciculations

Question 11

Strength Deficits: UMN

Answer 11

Weakness or paralysis:
- Ipsilateral (one side) for stroke
- Bilateral for SCI

Corticospinal Tract: Contralateral if lesion above pyramidal decussation, Ipsilateral if below.

Distribution: NEVER FOCAL

Question 12

Strength Deficits: LMN

Answer 12

Ipsilateral Weakness or Paralysis

Limited distribution: segmental or focal pattern