Compare and contrast central nervous systems pathologies part 1
Cerebral vascular accidents (CVA, stroke)
A CVA is a result of ischemia (blood clot) or hemorrhage (rupture in blood vessels) in the brain, causing sudden, focal neurological deficits. Ischemic strokes are more likely to occur in contrast to hemorrhagic strokes.
The risk factors contributing to the likelihood of developing a stroke are due to hypertension, arteriosclerosis, diabetes, cardiac disease, hyperlipidemia, smoking, sedentary lifestyle, and a previous history of TIA.
Ischemic strokes can be medically managed with tissue plasminogen activator (tPA) if given within the first 12 hours after the onset of symptoms. Post-12-hour management is management via anticoagulant and antihypertensive medications.
Hemorrhagic strokes are medically managed via craniotomy or arterial clipping of bleeding arteries. Management also involves antihypertensive and epileptic medications.
Cardinal symptoms of stroke
- Sudden weakness and/or numbness
- Difficulty speaking
- Difficulty walking
- Confusion
- Visual changes
- Facial drooping
Be able to spot the signs of stroke using the F.A.S.T. Acronym
- F: face Drooping: Does one side of the face droop or feel numb
- A: arm Weakness: Is one arm weak or numb? Does one arm drift downward when raised
- S: speech Difficulty: Is speech slurred, or are they unable to speak
- T: time to call 911: If any of these signs appear
Neurological deficits associated with stroke
- Left hemisphere injury
- Right side hemiplegia
- Right side hemisensory
- Speech-language deficits
- Trouble planning/sequencing movement
- Difficulty processing
- Right hemisphere injury
- Left side hemiplegia
- Left side hemisensory
- Visual-perceptual deficits
- Poor judgement
- Impulsive
- Abstract concepts are difficult to comprehend
- Difficulty perceiving emotions
- Middle cerebral artery stroke
- Contralateral hemiplegia with upper extremity involvement greater than lower extremity weakness
- Contralateral paresthesia with upper extremity weakness greater than lower extremity weakness
- Homonymous hemianopsia
- Motor speech deficits
- Broca’s aphasia
- Receptive speech deficits
- Wernicke’s aphasia
- Loss of gaze to the opposite side
- Anterior cerebral artery stroke
- Contralateral hemiplegia with lower extremity weakness greater than upper extremity weakness
- Contralateral paresthesia with lower extremity weakness greater than upper extremity weakness
- Urinary incontinence
- Apraxia
- Mutism (less verbal)
- Akinetic (less mobile)
- Posterior cerebral artery stroke
- Contralateral sensory loss
- Homonymous Hemianopia- a loss of half the visual field in both eyes
- Involuntary movements
- Intention tremors- unintentional movement of an extremity when performing a task
- Chorea- irregular, involuntary movements that can be chorea or writhing
- Hemiballismus- forceful throwing of body segments
- Visual agnosia: difficulty recognizing objects, people, places
- Dyslexia
- Thalamic pain: chronic, burning, or constrictive pain all over the body
- Oculomotor nerve palsy
- Generalized brainstem deficits
- Vertebral-basilar artery injured- occlusion of a large portion of the vertebral-basilar artery
- Locked-in syndrome develops
- Paralysis of all muscles except eye movement
- Cognition remains intact
- Locked-in syndrome develops
- Vertebral-basilar artery injured- occlusion of a large portion of the vertebral-basilar artery
- Ventral pons area deficits
- Millard-Gilbert syndrome
- Basilar artery injured- small branch of occlusion
- Impacts the facial and abducens cranial nerves, as well as the corticospinal tract
- Facial muscles and the lateral rectus are impacted on the ipsilateral side
- Inability to abduct the eye on the ipsilateral side
- Weakness of the upper and lower extremities contralateral side (hemiplegia)
- Millard-Gilbert syndrome
- Lateral medulla deficits
- Lateral medullary syndrome (Wallenburg syndrome or PICA syndrome)
- Impacts the posterior inferior cerebellar artery
- Deficits in cranial nerves- trigeminal and vagus on the ipsilateral side
- Deficits in pain and temperature
- Decreased gag reflex
- Nystagmus on the ipsilateral side
- Horner’s syndrome on the ipsilateral side
- Diplopia (double vision), anhidrosis (inability to sweat), ptosis (drooping of eyelid)
- Pain and temperature of the contralateral body
- Hemiparesis contralateral to the body
- Deficits in cranial nerves- trigeminal and vagus on the ipsilateral side
- Impacts the posterior inferior cerebellar artery
- Lateral medullary syndrome (Wallenburg syndrome or PICA syndrome)
Brunnstrom stages for recovery
The Brunnstrom stages of recovery are a guide to describe the motor recovery status post-stroke. Individuals post-stroke may progress through all stages or remain at a certain level for an extended period of time. There is no timetable for recovery.
- Stage 1: Flaccidity, with little or no voluntary movement
- Stage 2: Spasticity appears, and voluntary movement is possible
- Stage 3: Spasticity increases, and patients can voluntarily perform limb synergies
- Stage 4: Spasticity decreases, and patients can perform movement combinations that are not synergies
- Stage 5: Patients can perform complex movement combinations
- Stage 6: Spasticity disappears
- Stage 7: Patients return to normal function
Synergy patterns
Synergy patterns are abnormal muscle patterns developing status-post stroke. The two synergy patterns that exist are flexion and extension synergy patterns. Below are descriptions of muscle activation during the synergy patterns.
Flexion synergy
- Upper limb
- Scapula: retraction and/or elevation
- Shoulder: abduction and external rotation
- Elbow: flexion
- Forearm: supination
- Lower limb
- Hip: flexion, abduction, and external rotation
- Knee: flexion
- Foot and ankle: dorsiflexion
Extension synergy
- Upper limb
- Scapula: protraction and/or depression
- Shoulder: adduction and internal rotation
- Elbow: extension
- Forearm: pronation
- Lower limb
- Hip: extension, adduction, and internal rotation
- Knee: extension
- Foot and ankle: plantarflexion
Homonymous hemianopia
Key features
- Cause: Most commonly due to lesions in the optic tract, optic radiation, or occipital lobe on the opposite side of the vision loss (e.g., a left-sided brain lesion causes right homonymous hemianopsia).
- Common causes: Stroke (especially affecting the posterior cerebral artery), traumatic brain injury, and brain tumors.
- Symptoms:
- Bumping into objects on the affected side
- Reading difficulties (especially when vision loss is on the right)
- Difficulty with driving or navigating environments
- Diagnosis: Confirmed with visual field testing (perimetry).
- Rehabilitation focus:
- Visual scanning training
- Compensatory strategies (e.g., turning the head to scan the blind side)
- Environmental modifications
Apraxia
Ideomotor apraxia
Clinical presentation:
- A patient can describe a movement but cannot perform it when asked.
- May improve with automatic or habitual actions.
- Common errors include awkward or incorrect limb positioning during tasks like waving or brushing teeth.
Common causes:
- Left parietal lobe lesions
- Stroke, particularly in the dominant hemisphere
Ideational apraxia
Clinical presentation
- Misuse of objects (e.g., attempting to write with a fork)
- Skipping essential steps in a task (e.g., putting on shoes before socks)
- Incoherent task sequencing (e.g., pouring juice after trying to drink from the empty cup)
Common causes:
- Extensive damage to the left hemisphere
- Dementia or widespread cortical disease
Traumatic brain injury (TBI)
Types of injury:
- Open head injury: skull fracture that results in brain exposure
- Increased risk of the development of infection
- Closed head injury: no skull fracture or exposed brain
- Increased risk for intracranial pressure
Pathophysiology:
- Local brain injury
- Damage to a specific region of the brain due to bruising, bleeding, laceration, or swelling
- Coup-countercoup injury
- Injury in which the brain is damaged due to the point of impact and the opposite side due to rebound forces
- Diffuse axonal injury
- Tearing of axons and small vessels due to the acceleration of the brain in the skull, leading to neuronal death
- Edema
- Increased swelling due to increased intracranial pressure, typically from increased volume of cerebrospinal fluid in ventricles
- Hypoxic-ischemic injury
- Loss of cerebral circulation due to compromise, typically from deficits in the cardiovascular and respiratory systems
Stratification of brain injury
Brain injuries can be stratified into three (3) categories: mild, moderate, and severe based on symptomatology present. Stratification can be done with the use of the Glasgow Coma Scale (GCS):
- Mild TBI (i.e., concussion)
- GCS score: 13-15
- Loss of consciousness: 0-30 minutes
- Alteration of consciousness: brief; >24 hours
- Post-traumatic amnesia: <1 day
- Imaging: normal
- Recovery: full recovery of physical and cognitive function, with the patient seen in an outpatient setting
- Moderate TBI
- GCS score: 9-12
- Loss of consciousness: >30 minutes; less than 24 hours
- Alteration of consciousness: >24 hours
- Post-traumatic amnesia: 1-7 days
- Imaging: normal or abnormal
- Recovery: potential to have full recovery of physical and cognitive function with intense rehabilitation in an inpatient rehabilitation or skilled nursing facility
- Severe TBI
- GCS score: 8 or less
- Loss of consciousness: >24 hours
- Alteration of consciousness: >24 hours
- Post-traumatic amnesia: >7 days
- Imaging: normal or abnormal
- Recovery: permanent physical and cognitive impairment; typically in a nursing home setting or home setting with total care
Behavioral stratification of traumatic brain injury
Ranchos los amigos cognitive scale is utilized to classify behaviors through a predictable sequence. Individuals progress through levels in sequence but can plateau at any point. Level of behavior:
- Level I- No response
- Cognitive assistance needed: total assistance with all cognitive functions
- Response to stimuli: inconsistent responses to stimuli *Single-step commands: unable to follow single-step commands
- Characteristics of level: individuals are typically in a comatose state
- Level II- Generalized response
- Cognitive assistance needed: total assistance with all cognitive functions
- Response to stimuli: consistent, generalized response to stimuli
- Single-step commands: unable to follow single-step commands
- Characteristics of level: individuals in a vegetative state
- Level III- Localized response
- Cognitive assistance needed: total assistance with all cognitive functions
- Response to stimuli: localized response to stimuli
- Single-step commands: unable to follow single-step commands
- Characteristics of level: individuals within a minimally conscious state; able to inconsistently track objects and respond to their name
- Level IV- Confused, agitated
- Cognitive assistance needed: maximal assistance for cognitive function
- Response to stimuli: localized response
- Single-step commands: unable to follow single-step commands
- Characteristics of level: confused, combative, easily agitated, hypersexual behavior
- Level V- Confused, inappropriate
- Cognitive assistance needed: maximal assistance for cognitive function
- Response to stimuli: localized response *Single-step commands: unable to follow single-step commands
- Characteristics of level: confused, inappropriate behaviors (combative and hypersexual behaviors have subsided), severely impaired memory
- Level VI- Confused, appropriate
- Cognitive assistance needed: moderate assistance for cognitive function
- Response to stimuli: localized response *Single-step commands: able to follow single-step commands
- Characteristics of level: remote memory is more consistent than recent memory, requires assistance with problem solving, minimal carry-over with new tasks
- Level VII- Automatic, appropriate
- Cognitive assistance needed: minimal assistance for cognitive function
- Response to stimuli: localized response
- Single-step commands: able to follow single-step commands
- Characteristics of level: improve carry over with activity, minimal assistance for learning new tasks, increased awareness of deficits
- Level VIII- Purposeful and appropriate
- Cognitive assistance needed: stand-by assistance for cognitive function
- Response to stimuli: localized response
- Single-step commands: able to follow single-step commands
- Characteristics of level: able to integrate new and old memory into making decisions, able to make adjustments to behavior in social interaction with minimal assistance