Neurological Disorders

Consciousness

A state of awareness of oneself and the environment, and responses to the environment

Fully conscious

Spontenous, purposeful, independent response to a stimulus

1. arousal

2. awareness

2 components of consciousness

the reticular activating system

Arousal is mediated by

1. information processing

2. attention

3. maintains consciousness

the reticular activating system regulates: [3]

awareness

encompassess all cognitive funcitons

by the attentional, memory, language, and executive systems

Awareness is mediated yb

1. structural

2. metabolic

3. phsychogenic (functional)

Alterations in arrousal can be caused by disorders that are [3]

above the tentorium cerebelli

Supratentorial disorders location

Supratentorial disorders

Any diffuse dysfunction from disease processes affecting the cerebral cotex or the underlying subcortical white matter

extracerebral disorders

disorders outside the brain but inside the cranium

1. neoplasms

2. head trauma with subdural bleeding

3. accumulation of pus in subdural space

etiology of extracerebral disorders:

diffuse dysfunction

extracerebral disorders can produce what

intracerebral disorders

disorders within the brain that directly impair function to the thalamic and hypothalamic activating systems, or compress these structures

1. bleeding

2. infarction

3. emboli

4. tumours

intracerebral disorders etiology

below the tentoriu cerebelli

intratratentorial disorder location

1. accumulation of blood or pus

2. neoplasms

3. demyelinating disorders

4. impaired blood supply

intratratentorial disorder etiology

A decline in arousal

intratratentorial disorders produce what?

1. destruction or compression of the RAS and its pathways

2. destruction of the brainstem

intratratentorial disorders produce a decline in arousal by what?

decrease in attention, information processing, and consciousness

destruction of the RAS and itspathways would result in what?

a decline in arousal

metabolic disorders produce what?

metabolic disorders

disorders produce a decline in arousal be alterations in oygen, electrolytes, or glucose (hypoglycemia)

liver or renal failure

metabolic disorders may be caused by what?

Psychogenic disorders

Alterations in arousal and unresponsiveness may signal psychiatric disorders

1. level of consciousness

2. breathing patterns

3. pupillary reactions

4. oculomotor responses

5. motor responses

neurological functions to evaluate (health assessment) [5]

level of consciousness alterations

most critical index of nervous system functioning

alert and oriented to self, others, place, and time.

when someone is functioning at the highest level, they are:

1. alert

2. confusion

3. disorientation

4. lethargy

5. obtundation

6. stupor

7. light coma

8. coma

9. deep coma

Levels of consciousness [9

helps to evaluate the level of brain dysfunction and coma

How do breathing patterns assess neuro funciton?

pCO2

as consciousness decreases, the lower brainstem takes over and breating is regulated by changes in ?

posthyperventilation apnea

as consciousness decreases, the lower brainstem takes over and breating is regulated by changes in pCO2, this is called

Cheyne-Stokes

Hemispheric breathing pattern

1. central neurogenic hyperventillation

2. apneustic

3. cluster

4. ataxic

brainstem breathing patterns (4)

brain death

Irreversible function of the whole brain including that there s no brainstem function. There are no spontaneous respirations

1. ischemia

2. hypoxia

3. atropine

4. benzos

5. alcohol

6. barbirutares

Dilated, fixed pupils etiology [6]

brainstem changes

pupil alterations may indicate

hypothermia

Fixed pupils etiology

opiates

pinpoint pupils etiology

1. eyes do not turn in a conjugate manner

2. eyes move in direction of head turn (Doll eyes)

Abnormal occulomotor responses:

spontaneous and reflexive, turn in the opposite direction of the head

normal occulomotor response

evaluates the level of brain dysfunction/side or location of the brain damaged.

motor response changes help to evaluate the lelev of what?

non-purposeful and non- present

Abnormal motor responses

decerebrate posturing

involuntary extension of the upper extremities in response to external stimuli.

decorticate posturing

abnormal posturing in which a person is stiff with bent arms, clenched fists, and legs held out straight

1. seizure

2. head injury

3. alzheimer’s disease

amnesia etiology

CVA

Neglect syndrome etiology

1. agnosia

2. dysphasia

3. delirium

4. dementia

5. alzheimers disease

6. epilepsy and seizures

data processing disorders: [6]

trauma

primary brain injury etiology

Secondary brain injury

when there is an alteration in cerebral blood flow or O2 delivery (leading to CVA) or alterations in ICP

local or diffuse, open or closed.

brain injuries can be [2]

traumatic brain injury

alteration in brain function/pathology caused by an outside force

coup injury

Impact against an object causes injury to brain directly at the site of injury

Contrecoup injury

Impact on the brain is within the skull, injury is on the opposite side of the forceful impact

Diffuse axonal injuries

widespread areas of the brain are affected.

hematomas, contusions, coma, seizures, CTE

traumatic brain injury can lead to: [5]

subdural hematoma

bleeding between the brain and dura mater

epidural hematoma

Bleeding between the dura mater and the skull

Intracerebral hematoma

Bleeding within the brain

Concussion

Brain injury due to a jolt to the head or body where the head and brain move back and forth rapidly

1. headache

2. dizziness

3. fatigue

4. nervousness

5. irritability

6. insomnia

7. impaired concentration

post-concussion syndrome symptoms: [7]

may last weeks to longer periods of time

post-concussion syndrome may last for how long

mild concussion

concussion with immediate but brief clinical manifestations. headache, amnesia, might not feel like self for a few days

Classic cerebral concussion

Concussion with loss of consciousness for less than 6h with amnesia and confusion lasting hours to days

Diffuse axonal injury

Concussion where LOC lasts more than 6h to months/years in a coma

Chronic traumatic encephalopathy

develops from repeated raumatic brain injury from sports or blast injuries in soldiers. leads to progressive cognitive, physical, and behavioral decline.

At time of autopsy

Wen is chronic traumatic encephalopathy diagnosed?

1. tumour growth

2. edema

3. excessive CS

4. hemorrhage

Increased ICP etiology:

Cerebrospinal fluid

most readily displaced cranial content

Cerebral edema

increased fluid content in brain tissue

hydrocephalus

increased fluid content in ventricles/subarachnoid space or both.

1. trama

2. infection

3. hemorrhage

4. tumours

5. ischemia

6. infarction

7. hypoxia

cerebral edema etiology:

1. vasogenic

2. metabolic

3. interstitial

Types of cerbral edema (3)

Vasogenic cerebral edema

increased permeability of capilaries after injury to vascular structure leads to distruption of the blood brain barrier. Plasma proteins leak into EC spaces, water follows and enters brain white matter.

Leads to increased ICP, ischemia, and

Metabolic cerebral edma

When there is a toxic factor that affects the grey matter. The active transport system fails, and sodium enters the vell as potassium leaves. Water follows sodium into cells. Causes cerebral edema

Interstitial cerebral edema

Hydrocephalus where ventricular system becomes obstructed. The cerebrospinal fluid hydrostatic pressure in the ventricles increases. and flid is pushed into the white matter causing edema

Hypotonia

Decreased muscle tone, passive movement of a muscle with little to no resistance

1. spinal cord injury

2. CVA

hypotonia may be seen with: [2]

Hypertonia

Increased muscle tone, passive movement of a muscle occurs with resistance to stretch, spasticity.

1. cerebral palsy

2. parkinsons disease

Hypertonia may be seen with [2]

huntington’s disease

Degenerative disease that is hereditary and causes hyperkinetic movement and involuntary muscle contractions. Begins with the face and arms and eventually affects the entire body. Progressive dysfunction of cognitive abilities

Parkinson’s disease

Degeneration of basal ganglia and loss of dopamine producing neurons, meaning there is a decreased dopamine and increased cholinergic activity manifests as hypertonia.

progressive difficulty maintaining upright posture, speaking, swallowing, mask-like face

Parkinson’s s+s

Hemiparesis/hemiplagia

paresis/paralysis of upper and lower extremeties on one side

Paraparesis/parapalegia

paralysis/paresia of lower extremities, potential lower core of body as a result of lower spinal cord injury

Quadraparesis/quadrapalegia

Paralysis/paresis of all four etremeties, core of body as a result of upper spinal cord injury

Lou Gehrig disease

Amyotrophic lateral sclerosis example:

Lou gehrig disease

Neurodegenitive disorder involving upper and lower motor neurons. Leads to progressive muscular weakness eventually leading to death. Brain cognitive function remains intact.

Meningitis

Inflammation of the brain or spinal cord

infection

meningitis may be caused by

Multiple sclerosis

Autoimmune disease with degeneration of CNS myelin, leading to scarring and loss of axons

1. paresthesia

2. weakness

3. imparied gait

4. visual disturbances

5. urinary incontinence

Clinical manifestations of MS [5]

epilepsy

recurrence of seizures

seizure

transient disruptions in brain electrical function caused by abnormal excessive discharges of cortical neurons

status epilepticus

continuous (more than 5 minute) or rapidly ocuring seizures without recovery in between. Can be life-threatening

1. tonic-clonic

2. atonic

3. myoclonic

4. absense

Types of seizures:

Atonic seizure

A type of seizure that causes sudden loss of muscle strength. Also called drop attacks, the person can fall down but normally remains conscious

tonic clonic seizure

Seizure with rapid and rhythmic jerking of the arms and legs

myoclonic seizure

Burst of shock-like jerks of a muscle or group of muscles. usually does not last longer than a second or two