PTE 731: exam 3

according to the notes, what is the definition of a red flag noted during a neurological screen?

any alterations in mental status, sensations, reflexes, balance, and movement/strength

emergent referrals

immediate medical attention needed

non-emergent referrals

urgent but not life-threatening

what are the ascending motor tracts?

dorsal column-medial lemniscus tract and anterolateral spinothalamic tracts

what are the descending motor tracts?

lateral corticospinal and ventral corticospinal tracts

what is the primary responsibility of the lateral corticospinal tract?

controlling contralateral fine motor movements of the limbs, particularly the distal muscles

• crucial for skilled, precise voluntary movements

what is the primary responsibility of the anterior corticospinal tract?

controlling bilateral gross motor movements of the trunk and proximal musculature

• crucial for movements for posture and balance

the _____ tract is responsible for deep touch, proprioception, and vibratory sensations.

DCML

the ___ tract is responsible for pain and temperature sensations.

ALS

how would a therapist determine if a spinal cord injury is incomplete?

if there is an odd presentation, where right/left and UE/LE examinations don’t match

spinal cord syndromes chart

what are the two most common characteristics seen with a central cord lesion?

1. most common incomplete spinal cord injury

2. most commonly in cervical and thoracic spinal levels

a SCI patient presents with dysfunction and weakness in his upper extremities, specifically in his hands, along with using descriptors like tingling and burning for his pain in those regions. upon further questioning, he admits to peeing often (bladder dysfunction) and feeling like his bladder is always full (urinary retention). which spinal cord lesion should the therapist suspect?

central cord

T or F: central spinal cord lesions often present bilateral symptoms but the symptoms can be asymmetric.

T

extreme and forceful head movement into _________ can result in a central cord spinal lesion.

hyperextension

what are some examples of underlying pre-existing pathologies associated with central cord lesions?

• spondylosis

• atlantoaxial instability

• tethered cord

• spinal abscess

• syringomyelia

a patient presents with UE and LE motor loss to one side. the therapist performs other tests to rule out a stroke and discovers the patient cannot perceive pain on the contralateral UE and LE. however the patient experiences little to no sensation on the same side as the motor loss. what should the therapist conclude?

brown-sequard spinal cord lesion

describe a brown-sequard lesion.

transverse hemi-section of the spinal cord is affected 

list some possible traumatic and non-traumatic incidents that could lead to a brown-sequard lesion.

traumatic: stab or gunshot wound, fracture

non-traumatic: tumor, disc herniation, radiation

when performing the adult neurological exam, a SCI patient fails the pain/temp tests and the light touch tests, but experiences no problems with the proprioception tests. she also exhibits bilateral motor lost below T10. what spinal cord lesion should the therapist conclude?

anterior cord

extreme and forceful head movement into _________ can result in an anterior cord spinal lesion.

hyperflexion

list some direct and indirect incidents that could lead to an anterior spinal cord lesion.

direct: crush injury, burst fracture, gunshot or stab wound

indirect: occlusion, ischemia, or hypo-perfusion of the anterior spinal artery

a SCI patient complains of uncontrollable bowel and bladder movements along with increasing weakness in bilateral LEs. upon further inspection, the patient states he cannot feel sensations around his crotch region. which spinal cord lesion should the therapist suspect?

cauda equina

a cauda equina diagnosis should result in a 911 call. what five characteristics should a therapist be “on the look out for”?

1. bilateral neurogenic sciatica

2. reduced perineal sensation

3. loss of anal tone

4. altered bladder function leading to painless retention

5. loss of sexual function

list some examples of clinical signs and symptoms of a neurological impairment.

• confusion

• depression/irritability

• drowsiness/lethargy

• dizziness/light-headedness

• loss of consciousness

• vision or speech changes

no positive changes in gross motor exam →

no further testing required (like sensory function)

according to the notes, what are the seven steps of the neurological exam?

1. mental and emotional status

2. cranial nerves

3. sensory function

4. motor function

5. reflexes

6. neural tension

7. vision

what is Marcus Gunn Pupil?

occurs when there is damage to the optic nerve or severe retinal disease on one side; characterized by an abnormal response to light when performing the swinging flashlight test

• aka: relative afferent pupillary defect (RAPD)

describe the clinical presentation of Horner’s Syndrome.

ptosis (drooping eyelid), miosis (constricting pupil), and anhidrosis (lack of sweating on face)

what is the purpose of performing neural tension testing?

to assess whether the nerves are being stretched, compressed, or irritated during certain movements and to pinpoint the area where

vision makes up ___ of cortex making it one of the most important senses.

50%

saccades

fast, voluntary eye movements used to shift the eyes’ focus from one object to another

why might a therapist perform a saccadic visual test?

to gain insight into the function of the CNS, particularly the brain’s eye movement control centers that affect eye movement coordination, attention, and gaze control

describe the saccadic testing procedure.

• the patient is asked to alternate gaze between two stationary objects placed horizontally or vertically 12-18 inches apart

• the examiner observes how quickly and accurately the eyes move from one target to the other

what aspects of eye movement does the saccadiac procedure test?

accuracy, speed, corrective movements, hypermetria or hypometria

which diseases can display abnormal saccadic function?

Parkinson’s disease, Multiple Sclerosis, stroke, or TBI

what is the difference in clinical significance between delayed saccades or multiple corrective movements found during the testing?

delayed: neurological conditions affecting the frontal eye fields or brainstem pathways

multiple corrections: dysfunctions in cerebellar or brainstem regions

what is the vestibular ocular reflex (VOR)?

an involuntary reflex that keeps vision stable by making the eyes move in the opposite direction of head movement to keep focus on a target

• vital for maintaining clear vision while moving and preventing the world from appearing blurry or bouncing

what is the purpose of the VOR testing?

assess the function of the vestibular system (balance) and its interaction with the ocular system

describe the VOR head-thrust test.

• patient is asked to focus on a stationary target

• examiner moves patient’s head rapidly and unpredictably to one side and then the other

• eyes should remain fixed on the target during head movements in the VOR is functioning properly

  • positive if patient’s eyes move off target

describe the dynamic visual acuity test.

• patient is asked to read a line of letters from an eye chart

• test repeated while the patient’s head is moved side to side by the examiner

  • positive if reduce visual acuity occurs 

what is the smooth pursuit system?

a set of neurological circuits that allow the eyes to smoothly follow a moving object, keeping its image stabilized on the fovea for clear vision

what is the purpose of smooth pursuit testing?

evaluates and assesses the integrity of the visual tracking system via eyes’ ability to smoothly track a moving object

• critical for maintaining visual focus during slow, controlled movements

which disorders may produce an impaired smooth pursuit system?

cerebellar disorders, Parkinson’s disease, multiple sclerosis, concussion, and/or TBI

what is eye convergence?

the simultaneous inward movement of both eyes towards an object to ensure the object remains in focus on both retinas

• allows for clear, single vision at close distances 

what is the procedure for testing the eye convergence system?

• patient is asked to focus on a small object held at arms length in front of the face

• the object is slowly moved toward the patient’s nose

• the patient is instructed to follow the object with both eyes until he or she experiences double vision or can no longer maintain focus

list the convergence insufficiency symptoms.

• eye strain

• headaches

• double vision or blurred vision

• difficulty concentrating

the central nervous system is responsible for…

controlling bodily functions and is the center for behavioral and intellectual abilities

why do CNS drugs need to modify the activity of neurons to treat specific disorders or alter the general level of CNS arousal?

CNS drugs alter neurotransmitters so they can traverse the blood brain barrier to exert their effects on the CNS

what’s the difference between white mater and grey mater:

white mater: consists of myelinated axons of neurons (tracts) that ascend or descend between the brain and spinal cord

grey mater: area of synaptic connections between various neurons

cerebrum

composed of frontal, temporal, parietal, and occipital lobes; highest order of conscious function and integration

drugs affect on the cerebrum:

indirectly, except epilepsy and Alzheimer’s drugs

basal ganglia

group of specific areas located deep within the cerebral hemispheres; primarly involved in control of motor activities

drugs affect on the basal ganglia:

target BG movement disorders

diencephalon

area enclosing the third ventricle (thalamus and hypothalamus)

• thalamus: relays sensations and hypothalamus: controls hormones

drugs affect on the diencephalon:

influence body functions and sensations

mesencephalon and brainstem

midbrain, pons, medulla

drugs affect on the mesencephalon and brainstem:

impact alertness and arousal

cerebellum

plans and coordinates motor activity; maintains balance and posture

drugs affect on the cerebellum:

do not target actually! but if there is toxicity in the system, individual will demonstrate unwanted movements 

limbic system

cortical: amygdala, hippocampus, cingulate gyrus; hypothalamus, mammillary bodies, and septum pellucidum; controls emotional and behavioral activity

drugs affect on the limbic system:

target motivation, aggression, sexual activity, instinctive responses, anxiety, and psychosis

drug and brain region chart

why is the drug treatment complexity higher/more challenging in the central nervous system than the peripheral?

• complex structure and function of CNS

• blood-brain barrier limits drug entry

• neurotransmitters interact with multiple receptor subtypes

• neurons are plastic and adaptable

what is the blood brain barrier?

a highly selective membrane, comprised of tight endothelial junctions and astrocytic end-feet, that separates the blood circulating in the brain from the brain tissue

• protects the CNS from toxins and maintains a stable environment

by which two mechanisms can a drug enter the blood brain barrier?

1) must be lipid soluble or 2) via carrier-mediated transport

list the four neurotransmitters discussed in class.

1. biogenic amines

2. amino acids

3. neuropeptides

4. acetylcholine

what substances are associated with the neurotransmitter biogenic amines?

dopamine, norepinephrine, and serotonin

what substances are associated with the neurotransmitter amino acids?

glutamate/aspartate, GABA, and glycine

what substances are associated with the neurotransmitter neuropeptides?

substance P and endorphins/enkephalains

neurotransmitter chart

T or F: biogenic amines and neuropeptides required g-protein linked receptors to act on cells.

T

amino acids and acetylcholine require ___ ________ to act on cells.

ion channels

__________ neurotransmitters increase the likelihood that the postsynaptic neuron will fire an action potential by causing a depolarization of the postsynaptic membrane.

excitatory

________ neurotransmitters decrease the likelihood of postsynaptic firing by causing a hyper-polarization of the postsynaptic neuron.

inhibitory

what are the nine steps of a synaptic transmission?

1. action potential

2. neurotransmitter synthesis

3. neurotransmitter storage

4. neurotransmitter release

5. neurotransmitter reuptake

6. neurotransmitter degradation

7. postsynaptic receptors

8. presynaptic autoreceptors

9. membrane effects

action potential

initiates neurotransmitter release

neurotransmitter synthesis

blockading synthesis will eventually deplete the presynaptic terminal and impair transmission

neurotransmitter storage

impairing storage decreases synapses ability to transmit for extended periods

neurotransmitter release

increasing/decreasing neurotransmitter release modulates synaptic activity

neurotransmitter reuptake

movement of the transmitter molecule back into the presynaptic terminal thus terminating activity and allowing reuse

neurotransmitter degradation

enzymatic breakdown of released transmitter can terminate synaptic activity

postsynaptic receptor

antagonists can block the postsynaptic receptor, decreasing synaptic transmission (improvement can happen too)

presynaptic autoreceptors

serve as a method of negative feedback in controlling neurotransmitters release

membrane effects

alteration of membrane organization and fluidity modulate activity

T or F: presynaptic autoreceptors are always inhibitory

T!

what may occur following presynaptic drug actions?

• increase or block NT synthesis

• alter storage/package

• facilitate or inhibit NT release

• block NT reuptake

• inhibit NT metabolism

what may occur following postsynaptic drug actions?

• direct receptor agonists mimic NT

• receptor antagonists block NT

• contribute to up or down regulation

central nervous system drugs act on:

pre and post synaptic neurons

central nervous system drugs act by:

• altering impulse propagation

• altering NT synthesis, storage, release, reuptake, and degradation

• altering NT binding and stimulation of post-synaptic surface receptors

T or F: a single neuron influences and is influenced by multiple other neurons.

T

what’s the difference between divergence and convergence

divergence: one neuron → multiple

convergence: multiple neurons → one

what are the drug effects that make up sedative-hypnotic and anti-anxiety drugs?

sedative: calming, reduces anxiety

hypnotic: induces sleep

anxiolytic: relieves anxiety without heavy sedation

___________ is the issue leading to pathophysiology issues like insomnia and anxiety.

hyper-arousal

what are the goals for using sedative-hypnotic to treat insomnia?

• hasten sleep onset

• lengthen time asleep

• improve time in restful sleep

sedative-hypnotic drugs usually target the ______ and _______.

midbrain and brainstem

what are some risks seen when taking sedative-hypnotic drugs?

daytime sedation, confusion, delirium, falls, and dependency

T or F: sedative-hypnotic drugs are amongst the most commonly used and abused drugs worldwide.

T

describe the pharmacokinetics of sedative-hypnotic drugs.

lipophilic: readily absorbed, large Vd, and readily cross the blood-brain barrier

site of action: GABA-A or B receptors

termination of activity: liver metabolism

elimination: renal

GABA A vs GABA B chart