study guide all weeks

What is the role of M1?

The execution of voluntary movement.

What is the role of the premotor cortex?

Planning movements from external cues.

What is the role of the SMA?

Planning internal, sequential, and bimanual movements.

What does the lateral corticospinal tract control?

Fine, distal voluntary movement.

Where do most corticospinal fibers decussate?

At the pyramids of the medulla.

What does the corticobulbar tract control?

Voluntary movement of face and head muscles.

What is the role of the vestibulospinal tract?

Posture and balance control.

What is the role of the reticulospinal tract?

Gross motor patterns and tone regulation.

What does the tectospinal tract do?

Coordinates head and eye turning toward stimuli.

What are hallmark UMN signs?

Spasticity, hyperreflexia, Babinski sign.

What are hallmark LMN signs?

Flaccidity, fasciculations, muscle atrophy.

What causes spasticity?

Loss of corticospinal inhibition.

What causes flaccidity?

Loss of LMN input to muscle.

What is the Babinski sign?

Extension of big toe indicating UMN damage.

What is clonus?

Rhythmic contractions after stretch due to UMN damage.

What distinguishes rigidity from spasticity?

Rigidity is not velocity-dependent.

What does the basal ganglia direct pathway do?

Facilitates movement.

What does the indirect pathway do?

Inhibits movement.

How does dopamine affect the direct pathway?

Excites it to promote movement.

How does dopamine affect the indirect pathway?

Inhibits it to promote movement.

What degenerates in Parkinson's disease?

Substantia nigra pars compacta.

What are cardinal symptoms of Parkinson's disease?

Resting tremor, rigidity, bradykinesia, postural instability.

What causes Huntington's disease?

Striatal degeneration reducing indirect pathway activity.

What movement disorder is linked to Huntington's?

Chorea.

What is the cerebellum's primary function?

Coordination of movement and timing.

What is ataxia?

Clumsy, uncoordinated movement.

What is dysmetria?

Inaccurate reaching (over/undershoot).

What is intention tremor?

Tremor that increases near a target.

What is dysdiadochokinesia?

Impaired rapid alternating movements.

What type of gait comes from cerebellar lesions?

Ataxic wide-based gait.

What is decorticate posturing?

Flexed arms, extended legs.

What is decerebrate posturing?

Extension of arms and legs.

Which posture is more severe?

Decerebrate.

What is diffuse axonal injury?

Widespread shearing of axons from acceleration-deceleration.

What injury shows a lucid interval?

Epidural hematoma.

What vessel is torn in an epidural hematoma?

Middle meningeal artery.

What vessel is torn in subdural hematoma?

Bridging veins.

Who is more prone to subdural hematoma?

Older adults with brain atrophy.

What complication arises from rising ICP?

Brain herniation.

What does the ACA supply?

Medial frontal and parietal cortex.

What deficit comes from ACA stroke?

Contralateral leg weakness.

What does the MCA supply?

Lateral frontal, temporal, and parietal lobes.

What deficits come from MCA stroke?

Face/arm weakness, aphasia or neglect.

What does the PCA supply?

Occipital lobe and visual cortex.

What deficit comes from PCA stroke?

Homonymous hemianopia.

What is a TIA?

Transient ischemic attack resolving within 24 hours.

Why is a TIA important?

Indicates high risk of stroke.

What is the penumbra?

Salvageable brain tissue around an infarct.

Why is early treatment critical in stroke?

To save penumbra tissue.

What is neuroplasticity?

The brain's ability to reorganize after injury.

What is collateral sprouting?

Neighboring axons reinnervate a target.

What is regenerative sprouting?

A damaged neuron grows a new connection.

What is synaptic hypereffectiveness?

Remaining synapses become more efficient after injury.

What is denervation hypersensitivity?

Postsynaptic cells become more sensitive to remaining inputs.

What is functional reorganization?

The brain shifting functions to new areas.

What promotes neurogenesis?

Stem cells generating new neurons post-injury.

What is an enriched environment?

Stimulating settings that improve recovery.

Why does early rehab matter?

It enhances recovery and improves prognosis.

What non-neurological factors affect recovery?

Motivation, personality, and drive.