NPTE-PT Test Test Neuromuscular and Nervous Systems 1

Question 1

A patient presents with spasticity, hyperreflexia, and a positive Babinski sign in both lower extremities following a stroke. These findings are most consistent with a lesion affecting which neural structure?

Accepted Answer

Upper motor neurons of the corticospinal tract

Answer

Upper motor neuron (UMN) lesions interrupt descending inhibitory control, producing the classic triad of spasticity, hyperreflexia, and a positive Babinski sign. Lower motor neuron lesions instead cause flaccidity, hyporeflexia, and muscle atrophy.

Question 2

A patient with a complete T10 spinal cord injury would most likely present with which of the following functional profiles?

Accepted Answer

Paraplegia with full trunk control and intact respiratory function

Answer

The diaphragm is innervated by C3–C5 (phrenic nerve), so a T10 lesion spares respiratory function entirely. T10 injuries result in paraplegia with loss of lower extremity motor/sensory function and variable trunk control, but the upper extremities and breathing remain intact.

Question 3

Which descending motor pathway carries the primary commands for fine, skilled voluntary movements of the distal upper extremities, including individual finger control?

Accepted Answer

Lateral corticospinal tract

Answer

The lateral corticospinal tract originates from primary motor cortex, decussates in the medullary pyramids, and synapses directly on anterior horn motor neurons controlling distal limb musculature. It is the dominant pathway for fine voluntary motor control, especially of the hands and fingers.

Question 4

On repetitive nerve stimulation testing at 3 Hz, a patient shows a decremental response in the compound muscle action potential (CMAP) amplitude. Which disorder does this finding most strongly suggest?

Accepted Answer

Myasthenia gravis

Answer

In myasthenia gravis, postsynaptic acetylcholine receptors are reduced by autoantibodies, so successive nerve stimuli deplete the available quanta and CMAP amplitude decrements by ≥10%. Lambert-Eaton syndrome, by contrast, shows an incremental response because high-frequency stimulation mobilizes more calcium and acetylcholine release.

Question 5

Selective damage to the dorsal columns of the spinal cord, as seen in the posterior cord syndrome or subacute combined degeneration, would produce ipsilateral loss of which sensory modalities below the lesion?

Accepted Answer

Proprioception and vibration sense

Answer

The dorsal columns (fasciculus gracilis and cuneatus) carry ipsilateral proprioception, vibration, and discriminative (two-point) touch. Pain and temperature travel in the contralateral anterolateral (spinothalamic) tract. Isolated dorsal column injury therefore spares pain/temperature while eliminating position sense and vibration.

NPTE-PT Test Practice Test

NPTE-PT Test Practice Test

NPTE-PT Test Test Neuromuscular and Nervous Systems 1