LESSON 1: PART 9 - INTRODUCTION TO NEUROLOGICAL CONDITIONS

Upper motor neuron (UMN) syndrome

As a result of damage to the CNS and descending pyramidal tracts.

Upper motor neuron (UMN) syndrome

Muscle affected are in groups

Upper motor neuron (UMN) syndrome

Atrophy is slight due to disuse

Lower motor neuron (LMN) syndrome

lesions that affect the anterior horn cell and peripheral nerve

Lower motor neuron (LMN) syndrome

An individual muscle may be affected, groups

Lower motor neuron (LMN) syndrome

(neurogenic) atrophy is pronounced (up to70 – 80%)

Lower motor neuron (LMN) syndrome

Flaccidity and hypotonia present with loss of DTR’s

Upper motor neuron (UMN) syndrome

Spasticity is present with hyperactivity of the tendon reflex and extensor response (Babinski sign)

Upper motor neuron (UMN) syndrome

Absent fascicular twitches

Lower motor neuron (LMN) syndrome

fascicular twitches and fibrillations may be present

Lower motor neuron (LMN) syndrome

Abnormal NCV in EMG

Upper motor neuron (UMN) syndrome

Normal NCV, no denervation potential

MUSCLE TONE

Defined as the resistance of muscle to passive elongation or stretch

MUSCLE TONE

represents a state of slight residual contraction in normally innervated, resting muscle, or steady-state contraction.

• hypertonia

• hypotonia

• dystonia

MUSCLE TONE ABNORMALITIES

Hypertonia

increased tone above normal resting levels → Can either be spasticity or rigidity

SPASTICITY

a motor disorder characterized by a velocity-dependent increase in muscle tone with increased resistance to stretch.

SPASTICITY

has to increase in tonic stretch reflex with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex

RIGIDITY

increased resistance to passive motion which affects all striated muscles.

Clonus

is characterized by the cyclical, spasmodic alternation of muscular contraction and relaxation in response to sustained stretch of a spastic muscle