536 Abrupt Lesions PT Implications

mild TBI

TBI that causes concussion without structural injury

moderate

TBI that often involves structural injury

severe

TBI that involves loss of consciousness for longer than 6 hours

headache, disorientation & disturbances in cognition, dizziness, nausea, vomiting, mood and attention disorders, pain

common symptoms of concussion

True

True or false? The severity of amnesia related to the severity of the head injury?

retrograde amnesia

Refers to the loss of memories formed before the injury.

anterograde amnesia

Refers to the inability to form memories after the injury

neuropathic pain

common pain sensed with TBIs as a result of damage to sensory pathways (specifically, the thalamus)

ventral posterior nucleus

specific area of the thalamus that, when damaged, causes sensory abnormalities including hypoesthesia, hypoalgesia, and hyperalgesia

Glasgow Coma Scale (GCS)

How can altered consciousness and mental status be assessed after a TBI?

coma

Disorder of consciousness characterized by the following:

- Eyes do not open at all

- No communication

- No awareness, command following, or purposeful responses

Unresponsive Wakefulness

Disorder of consciousness characterized by the following:

- Eyes open at times but not sustained, sluggish

- No communication

- No awareness, command following, or purposeful responses

Minimally Conscious State

Disorder of consciousness characterized by the following:

- Eyes open more frequently, potentially progressing to normal eye opening/trackin

- Potential for yes/no nodding or gestures/verbal responses that may be inconsistent or unreliable

- purposeful but inconsistent awareness

ascending reticular activating system

Collection of brainstem nuclei that provide excitatory input to the cortex; damage at midbrain leads to altered states of consciousness.

Cushing's Triad

Signs of increased intracranial pressure or brainstem compression

hypertension, bradycardia, irregular respiration

Cushing's Triad symptoms

respiratory

These issues associated with TBI must be controlled immediately (especially when the pons and medulla are involved)

Cheyne-Stokes breathing

a distinct pattern of breathing characterized by oscillating patterns between rapid breathing and momentary pauses

hyperventilation

the condition of taking abnormally fast, deep breaths

apneustic breathing

a distinct pattern of breathing characterized by prolonged pauses occurring following inspiration

ataxic breathing

a distinct pattern of breathing characterized by irregular breathing rates and tidal volumes

Glasgow Coma Scale, CT first, MRI second, clinical symptoms

How do we diagnose TBIs

highest: 14

lowest: 3

highest and lowest score on glasgow coma scale

3-8

glasgow coma scale score indicating a minimally conscious state

cranial nerve reflexes, abnormal posturing

in comatose patients, how can the level of TBI damage be estimated?

flaccidity

Limpness or loss of muscle tone that often occurs at the onset of the brain injury

decorticate posturing

abnormal posturing that involves flexion of the arms, clenched hands,

and extended legs with pointed toes (TBI)

decerebrate posturing

Abnormal posturing that involves clenching the jaw and extension of the

arms and legs. That patient is rigid, and limbs are rotated internally (TBI)

decorticate posturing

Abnormal posturing that suggests severe injury above the midbrain.

decerebrate posturing

Abnormal posturing that suggests severe injury at or below the level of the midbrain; poor prognosis

more accurately estimates herniation, minimizing secondary brain damage

Why would MRI potentially be a better for TBI diagnosing?

diffusion tensor imaging (MRI)

method to detect diffuse axonal injury that tracks the diffusion of water in order to trace myelinated axon

tracts; not routinely used in practice

N-acetylaspartate (NAA)

levels that correlate with the severity of damage and neurological outcomes of a TBI (second-most abundant amino acid in the CNS, after glutamate)

False (decrease)

True or false? Following TBI, NAA levels increase.

catheters in lateral ventricles/subarachnoid space, transcranial color doppler

How can ICP be monitored after a TBI?

infection

risk of catheters to monitor ICP

concussion

SCI in which a blow or violent shaking results in temporary loss of function

contusion

SCI in which the cord surface remains intact while the white or gray matter is damaged

laceration

SCI in which the spinal cord surface and tissue is torn

1. light touch/pinprick sensitivity

2. myotomes

How can we test for injury level of a SCI?

True

True or False? complete lesions cause loss of sensory and motor function while incomplete lesions leave some axons intact

paraplegia

Affects the lower trunk and limbs and is caused by

damage in the thoracic or lumbar regions of the spine

Quadriplegia

Affects all four limbs and the

trunk and is caused by injury in the cervical spine

80%

Symptoms of SCI common in 80% of SCI patients.

denervates phrenic n → paralysis of diaphragm → requires ventilator

How can SCIs at C4 affect the respirator system?

weak/paralyzed abdominal or intercostal mm → impaired coughing → secretion build-up & obstructive sleep apnea

How can SCIs between C5 and T12 affect the respiratory system?

pain, weakness, fatigue

common complaints that reduce the quality of life following SCI

autonomic dysfunction, depression, decreased mobility

what causes fatigue for those with a SCI

sleep, bladder & bowel function, cardiopulmonary function, sexual activity

Autonomic dysreflexia is a common syndrome in SCI that affects what aspects of life?

1. increased BP, heart rhythm

2. pounding headache

3. sweating/flushing of face, neck, shoulders

4. visual disturbances

5. anxiety

6. bladder/bowel incontinence

7. sexual dysfunction

8. compromised immune function

Following SCI, descending regulation of autonomic activity is lost, leading to what symptoms?

UMN: spastic bladders & bowels, erectile function preserved without ejaculation

bowel/bladder/sexual function symptoms of SCI above T12

LMN: flaccid bladders, bowels, and genitals.

bowel/bladder/sexual function symptoms of SCI below T12 (S1-S2)

CT scans (reliable)

MRI (better detect soft tissue damage, syringomyelia, & hematoma

What are good diagnostic methods for SCI?

UMN

Damage to the corticospinal tract creates UMN or LMN signs?

hyperreflexia or clonus, increase muscle tone, plantar reflex (Babinski), weakness w/o muscle wasting

UMN signs resulting from damage to the corticospinal tract

LMN injuries, partial UMN lesions that cause paralysis

What type of SCI injuries are more likely to cause "muscle wasting".

False (rapid onset)

True or False? Ischemic stroke symptoms are typically delayed.

aorta → ICA → (carotid foramina) → circle of Willis → MCA & ACA

flow of the significant arteries from the aorta to the brain (that run through the carotid foramina)

aorta → vertebral arteries → (foramen magnum) → basilar artery → joins Circle of Willis

flow of the significant arteries from the aorta to the brain (that run through the foramen magnum)

middle cerebral artery

artery that is the most common source of ischemic events, serving the lateral portions of the cerebrum

- CL weakness (UE/face > LE)

- CL sensory loss (UE/face > LE)

- Aphasia

- hemineglect

generalized deficits of the MCA

stem infarcts

proximal MCA occlusions that affect all 3 divisions (superior, inferior, deep)

anterior cerebral artery

Infarcts in this artery affect the medial frontal lobes, parietal lobes and anterior basal ganglia

- CL weakness (LE>UE)

- CL sensory loss (LE>UE)

- Apathy, lack of motivation

generalized deficits of infarcts in the ACA

occipital lobes

what does the PCA supply?

- visual deficits, field cuts

- apathy and personality changes

- memory loss

generalized deficits of infarcts in the PCA

watershed zones

Intermediate regions between two adjacent blood vessels.

drop in BP

common cause of infarcts in watershed zones

true

true or false? terminal arteries in the watershed zones are very fine and have high internal resistance

proximal arm and leg weakness

Watershed infarcts in ACA-MCA watershed zone region cause these symptoms:

higher-order visual processing

Watershed infarcts in MCA-PCA watershed zone region cause these symptoms:

long tract signs

signs referable to the pyramidal tracts (corticospinal and corticobulbar), posterior column-medial lemniscus pathway, and the spinothalamic tracts

posterior

long tract signs occur when there is damage to posterior or anterior circulation of the brain

third nerve palsy, cerebellar ataxia

smaller infarcts in the midbrain cause what symptoms?

facial, abducens, mandibular palsy

smaller infarcts in the pons cause what symptoms?

lateral medullary syndrome, ipsilateral facial deficits, CL body deficits, deafness, vertigo

smaller infarcts in the medulla cause what symptoms?

ipsilateral cerebellar ataxia, nausea, vomiting, dizziness, vertigo

smaller infarcts in the cerebellum cause what symptoms?

coma

symptoms of larger infarcts in the midbrain

locked syndrome, death

symptoms of larger infarcts in the pontine

death

symptoms of larger infarcts in the medullary

sudden, severe headache

what specific symptoms characterizes a subarachnoid hemorrhage

nausea, vomiting, syncope, neck pain, coma, confusion, lethargy, motor weakness, cranial nerve palsies, seizures

additional symptoms of subarachnoid hemorrhage

3 months

around 90% of neurological recovery occurs in what time period following a stroke

neuroplasticity

changes in the synaptic connectivity of the nervous system

true

True or False? The brain is able to change its pattern of synaptic connectivity, which allows us to store new information.

Hebbian plasticity

If a synapse is repeatedly activated at the same time that the postsynaptic cell fires an action potential, that synapse will become "stronger" and increase the likelihood of causing an action potential in the postsynaptic cell; neurons that fire together wire together

increasing strength of existing synapses, unsilencing silent synapses, modifying inhibitory input

what are the 3 ways in which Hebbian plasticity occur?

taken over by nearby neurons

When neurons are lost, how can their function be preserved

cognitive, associative, autonomous

3 stages of motor learning

cognitive

stage of motor learning in which existing neural patterns are used to try to execute a movement carried out by the damaged area(s)

associative

stage of motor learning in which the correct sequence of neural activity

in the cortex has been figured out, but the motor program has not been stored in subcortical structures

autonomous

stage of motor learning in which the motor program is solidified in the cortex and subcortical motor areas

1. align symptoms to infarct location

2. symptom onset suggest suggest the infarct type

3. CT (ideal)

4. MRI (follow-up imaging)

diagnosis of both ischemic and hemorrhagic strokes

30 minutes

How soon can an MRI detect an ischemia

2-6 hours

How soon can an MRI detect an infarct

rapid

embolic infarcts cause slow or rapid symptom onset?

slow

thrombotic infarcts cause slow or rapid symptom onset?

- typically slower onset

- signs of ICP elevation

- same signs as ischemic stroke

symptoms of hemorrhagic stroke

- reduce ICP surgically or w/ mannitol

- avoid glucocorticoids (increases mortality)

Treatment for TBIs

1. severity of impaired responsiveness

2. duration of alt. consciousness

3. duration of posttraumatic amnesia

4. degree of brainstem damage

5. degree of hypoxemia/hypotension

6. cerebral edema & hematoma

7. epilepsy w/in 7 days of injury

8. older age at injury

9. brain injury history

10. ICP increase > 20 mmHg

10 factors that determine prognosis after a TBI