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 than hemorrhagic strokes.

Definitions

Transient ischemic attack (TIA)

A brief episode in which a temporary loss of blood flow causes stroke symptoms such as vision deficits, weakness, and numbness. Symptoms will resolve without medical intervention. The timeframe for symptoms is variable but less than 24 hours.

Risk factors that contribute to the likelihood of developing a stroke include hypertension, arteriosclerosis, diabetes, cardiac disease, hyperlipidemia, smoking, a 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. Management beyond that window involves anticoagulant and antihypertensive medications.

Hemorrhagic strokes are medically managed via craniotomy or arterial clipping of bleeding arteries. Management also involves antihypertensive and antiepileptic medications.

Definitions

Craniotomy

A surgical procedure in which blood is removed from the brain via holes drilled into the skull.

Arterial clipping

A procedure in which a clamp is placed on the hemorrhaging brain artery to reduce blood flow and stop bleeding.

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 — call immediately 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 judgment
  • Impulsive
  • Abstract concepts are difficult to comprehend
  • Difficulty perceiving emotions
• Middle cerebral artery stroke
  • Contralateral hemiplegia with upper extremity weakness 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 hemianopsia: 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 injury: occlusion of a large portion of the vertebral-basilar artery
    • Locked-in syndrome develops
      • Paralysis of all muscles except eye movement
      • Cognition remains intact
• Ventral pons area deficits
  • Millard-Gubler syndrome
    • Basilar artery injury: occlusion of a small branch
    • 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 on the contralateral side (hemiplegia)
• Lateral medulla deficits
  • Lateral medullary syndrome (Wallenberg 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)
      • Loss of pain and temperature sensation on the contralateral body
      • Hemiparesis on the contralateral side

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 hemianopsia

Definitions

Homonymous hemianopsia

A type of visual field loss that affects the same side of the visual field in both eyes.

Key features

• Anatomical basis: Most commonly, 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

Definitions

Apraxia

A motor planning disorder characterized by the inability to execute purposeful, learned movements, even when the individual has the physical capacity and desire to perform the movement. It is commonly caused by lesions in the left hemisphere of the brain, particularly the parietal and frontal lobes, and can significantly impair functional independence.

Understanding the various forms of apraxia is essential for physical therapists working in neurological rehabilitation.

Ideomotor apraxia

Definitions

Ideomotor apraxia

The inability to perform purposeful motor acts on command or imitation, even though the idea of the task is understood and motor function is intact.

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

Definitions

Ideational apraxia

The inability to carry out a sequence of actions to achieve a goal, due to loss of the concept of the task.

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)

Definitions

Traumatic brain injury (TBI)

An injury to the brain caused by a force to the skull that produces rotational acceleration, with severity that varies by case.

Types of injury:

• Open head injury: skull fracture that results in brain exposure
  • Increased risk 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, typically due to compromise of 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; <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

Definitions

Alteration of consciousness

Change in baseline perception, awareness, and mental functioning.

Post-traumatic amnesia

Inability to recall events occurring after injury.

Retrograde amnesia

Inability to recall events preceding the injury.

Imaging

Magnetic resonance imaging (MRI) is utilized to assess the level of injury.

Behavioral stratification of traumatic brain injury:

Rancho 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: confused and inappropriate but no combative characteristics
• 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: improved carryover 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