NEURO Final Flashcards
Neurons that are deprived of oxygen for a prolonged period:
Release glutamate, which causes overexcitation of the surrounding neurons
Excitotoxicity begins with:
Persistent binding of glutamate to N-methyl-D-aspartate (NMDA)–type receptors in the postsynaptic cell membrane
Cellular effects of excitotoxicity include:
- Excessive production of lactic acid
- Destruction of cellular proteins
- Cellular edema
- Interference of mitochondria functions
Which types of memory are affected by an injury to the hippocampus?
Memory of names and events
In the mature central nervous system (CNS), axonal regeneration is impeded by:
- Glial scar formation
- Absence of neural growth factor
- Release of growth inhibiting factors
Constraint-induced movement after a stroke requires:
Repetitive, task-specific functional movements of only the affected UE
Learning an individual’s name requires:
Long term potentiation (LTP)
In what stage does myelination of axons begin:
Fetal stage
In what stage do the endoderm, mesoderm, and ectoderm develop:
Pre-embryonic stage
In what stage do organs form:
Embryonic stage
Somites are derived from which pre-embryonic cell layer?
Mesoderm
Which direction are somites added?
Rostral-to-caudal direction
What form of Spina Bifida is the least severe and usually does not result in neural symptoms?
Spina bifida occulta
During acute appendicitis, the contribution of the somatosensory nociceptive afferents is:
Signaling conscious awareness of pain in the umbilical region
Areas of the central nervous system (CNS) that modulate autonomic control include:
Thalamus, hypothalamus, limbic system
Characteristics of the autonomic efferent system
- Innervates blood vessels in skeletal muscle
- Hormones regulate effector control
- Usually a two-neuron pathway with a synapse outside the CNS
- Neurotransmitters are used for signaling
Sympathetic activation does NOT produce:
Increased digestive activity
Capacitance vessels include:
Skeletal muscle veins and venules
Drugs that block beta-1 (β1) receptors are used to treat:
Tachycardia
Where are the cell bodies of sympathetic preganglionic neurons located?
Lateral horn of SC T1-L2 level
What is NOT a cause of syncope?
Hyperglycemia
Which proteins are NOT involved in the active process of muscle contraction?
Titin
What is the purpose of alpha-gamma coactivation?
Maintain muscle spindle sensitivity when extrafusal muscle fibers contract
Reciprocal inhibition produces inhibition of the alpha motor neurons to:
Antagonist muscle
What major factor limits movement in individuals who have had a stroke?
- Paresis caused by decreased agonist activation
- Loss of ability to fractionate movement
- Abnormal timing of muscle activation
If the lower motor neurons to a muscle are destroyed, what signs affect the denervated muscles?
Loss of reflexes and atrophy
List the five separate, parallel cortico-basal ganglia-thalamic loops and their functions
(1) Motor loop: adjusts the activity of cortical upper motor neurons (corticospinal, corticobrainstem, and corticopontine tracts) and reticulospinal tracts.
(2) Oculomotor loop: makes decisions about eye movements and spatial attention.
(3) Executive loop: goal-directed behavior, including evaluating information for making perceptual decisions, planning, and choosing actions in context.
(4) Behavioral flexibility and control: recognition of social disapproval, self-regulatory control, selecting relevant knowledge from irrelevant, maintaining
attention, and stimulus-response learning.
(5) Limbic: Links limbic, cognitive, and motor systems; identifies value of stimuli; involved in reward-guided behaviors; monitors errors in predictions; concerned with seeking pleasure.
The cortico-basal ganglia-thalamus motor loop contributes to:
- Regulation of muscle force
- Sequencing of movements
- Regulation of muscle tone
- Selection and inhibition of specific motor synergies
Nystagmus, dysequilibrium, truncal ataxia
Vestibulocerebellum
Wide-based, staggering gait
Spinocerebellum
Dysarthria
Vermis
Dysdiadochokinesia, dysmetria, and action tremor, and wide-based, staggering gait
Cerebrocerebellum
What is the most functionally important branch of the cervical plexus?
Phrenic nerve
Which one of the plexes innervates the posterior thigh and most of the leg and foot?
Sacral
What type of lesion would cause: lack of posterolateral sensation in digits four and five of the right hand; intact sensation of all fingertips; paralysis of long extensors for right wrist and finger; paralysis of the right supinator; sensation and motor function intact for remainder of the body
Right radial nerve lesion
What type of lesion would cause: Babinski’s sign; paralysis; hyperreflexia; muscle hypertonia; complete loss of all sensation below the level of the umbilicus
Complete T10 spinal cord lesion
What type of lesion would cause: Weakness of the quadriceps on the right side; no other motor or sensory loss
Right L3 ventral root lesion
What type of lesion would cause: Decreased strength in right deltoid and biceps; decreased sensation in anterolateral right upper arm; sensation and motor function intact for the remainder of the body
Right C5 spinal nerve lesion
What type of lesion would cause: Paralysis of the right iliopsoas and all muscles in the right lower limb; loss of discriminative touch and conscious proprioception in the right lower limb; loss of discriminative pain and temperature sensation in the left lower limb and left buttock region
Right hemi-lesion of spinal cord, L1 segment
Autonomic dysreflexia is characterized by:
Abrupt increase in blood pressure and pounding headache
Complete spinal cord lesions above which level results in long-term ventilator dependence?
C4
Loss of descending sympathetic control as a result of complete spinal cord lesions above T6 result in which of the following?
- Orthostatic hypotension
- Autonomic dysreflexia
- Poor thermoregulation
The Hallpike maneuver was designed to:
Provoke maximal movement of otoconia in the posterior semicircular canals
What happens second during excitotoxicity?
Stimulation results in an influx of Ca2+ into cell and indirectly facilitates release of Ca2+ stores
What is the hippocampus not responsible for?
Performing motor acts (procedural memory)
Constraint-Induced Movement Therapy
Type of task specific functional movements used in individuals with chronic dysfunction resulting from a stroke
How would constraint-induced movement therapy be performed?
- Use of unaffected UE is constrained by a sling
- Pt then undergoes intense practice of functional movements with affected UE
Long Term Potentiation (LTP)
Cellular mechanism for memory that results from synthesis/activation of new proteins and growth of new synaptic connections
What rehabilitation mechanism(s) promote beneficial neural plasticity?
- Task specific practice/training (essential for motor learning)
- Early initiation of rehabilitation (improved recovery)
Meningocele (Spina Bifida)
Protrusion of the meninges through bony defect
Meningomyelocele (Spina Bifida)
Most severe
- Always results in abnormal growth of SC
- Results in some LE dysfunction (usually bowel/bladder)
Cerebral Palsy
Movement and postural disorder caused by permanent, non progressive damage to developing brain
Spastic CP
Damaged neurons adjacent to ventricles
- Results in increased muscle stiffness or hypertonicity
Athetoid (Dyskinetic) CP
Damage to basal ganglia
- Characterized by writhing/uncoordinated movements
Ataxic CP
Damage to cerebellum
- Characterized by incoordination, tremors and weakness
ADHD
Characterized by developmentally inappropriate inattention, impulsivity and motor restlessness
Treatment for ADHD
Stimulant drugs
What do stimulant drugs do for ADHD as a treatment?
Increases the availability of dopamine and norepinephrine in synapses which leads to improved function in some
Signs and Symptoms of Autism Spectrum Disorders
- 12 mo of age
- Poor eye contacted
- Decreased shared attention
- Decreased communication
- Decreased social interaction
Autistic Disorder
- Limited interests
- Appear to lack imagination
- Not interested in interacting with others
Asperger’s Disorder
- Speak/have normal or higher intelligence
- Limited social skills
- Narrow range of interests
- Repetitive/frequently obsessive behaviors that interfere with school, work or social life
Pervasive Developmental Disorders
- Atypical behaviors similar to autism or Asperger’s disorder, but do not meet all criteria for diagnosis of autism/Asperger’s
What neurologic development happens in the embryonic stage (day 15 - end of wk 8)?
- Neural tube formation (day 18 - 26)
- Brain formation (day 28)
Growing Into Deficit
Nervous system damage occurring early is not evident until damaged system normally becomes functional
Developmental Coordination Disorder
Classification for children with normal intellect w/o TBI, CP or other neurologic problems
- Lack motor coordination to perform tasks that most children their age able to perform
- Usually continues into adulthood
What time period is the CNS most susceptible to major malformation?
Between day 14 and wk 20
What are the effects of alcohol abuse during pregnancy?
FAS or alcohol related birth defects
- Abnormally small head, indistinct philtrum, thin upper lip, short vertical space between open eyelids
- Cognitive, movement and behavioral problems
- Impaired intelligence, memory, language, attention, reaction time, visuospatial abilities, decision-making skills, goal-oriented behavior, fine/gross motor skills, social/adaptive functioning
Contribution of somatosensory nociceptive afferents during acute appendicitis:
Signaling conscious awareness of pain in umbilical region
What results from sympathetic activation?
- Increased blood flow to active muscles
- Increased blood glucose levels
- Dialation of bronchioles
- Increased HR
What does autonomic regulation of the heart depend on?
Parasympathetic fibers of vagus nerve and sympathetic fibers from thoracic level
Signs of Horner’s syndrome
- Group of symptoms seen when lesion to descending sympathetic tract, upper thoracic SC, brachial plexus or cervical sympathetic chain affected (sympathetic activity to one side of head decreased)
- Ipsilateral upper eyelid drooping
- Constriction of pupil
- Skin vasodilation
- Absence of sweating of ipsilateral face/neck
Causes of syncope
- Strong emotions
- Prolonged bed rest and then position change
Describe the process of muscle contraction
- Binding of Ca2+ with troponin causes tropomyosin to move, exposing active sites on actin for myosin to bind
- When the head of myosin swivel, the sarcomere actively contracts
Signs of UMNL: Spastic
More muscle contraction
Signs of UMNL: Hypertonic
More muscle tone
Signs of UMNL: Hyperreflexic
More muscle reflexes
Signs of UMNL: Disuse Atrophy
More disuse of the muscle
Signs of UMNL: Babinski Sign
Toes point up
Signs of LMNL: Flaccid
Less muscle contraction
Signs of LMNL: Hypotonic
Less muscle tone
Signs of LMNL: Hypreflexia
Less muscle reflexes
Signs of LMNL: Denervation Atrophy
Less muscle innervation
Signs of LMNL: Babinski Sign
Toes point down
Symptoms of Lesions: Vestibulocerebellum
Unsteadiness, truncal ataxia - difficulty maintaining sitting/standing balance
Nystagmus - abnormal eye movement
Symptoms of Lesions: Spinocerebellum
Intentional tremor - shaking of limb during voluntary movement
Ataxic gait - wide based unsteady, staggering, veering gait
Dysarthria - slurred, poorly articulated speech
Dysdiadochocinesia - inability to rapidly alternate movements
Dysmetria - inability to accurately move an intended distance
Movement decomposition - moving each joint separately during an activity
Cerebrocerebellum
Finger ataxia - inability to move fingers in coordinated mater
Dysarthria - slurred, poorly articulated speech
Goal Directed Behavior Loop (Basil Ganglia)
- Makes perceptual decisions
- Plans and decides upon actions in context
- Divergent thinking
Social Behavior Loop (Basil Ganglia)
- Recognition of social disapproval
- Self regulatory control
- Select relevant information from irrelevant, maintains attention and decision making
Emotion Loop (Basil Ganglia)
- Emotions
- Concerned with seeking rewards
Signs of akinetic-rigid Parkinson’s
- Akinesia/hypokinesia/bradykinesia
- Generally, hypokinesia or bradykinesia (not akinesia)
- Rigidity
- Postural unsteadiness
- Resting tremor
- Freezing during movement (FOG)
- Often triggered by visual cues
- Visuaoperceptual impairment
- Mask like facial expression
- Non-motor signs: depression, psychosis, Parkinson’s dementia, autonomic dysfunction
- Difficulty initiating movement
- Less control of amount of force their muscle produce
- Prone to falls
- Postural corrections are slow
- Cogwheel rigidity
- Rigidity may be present even during sleep
- Resting tremor including pin rolling tremor of hands
Huntington’s Disease
Autosomal dominant hereditary disorder that causes degeneration in many areas of the brain, primarily in stratum and cerebral cortex
- Characterized by hyperkinesia
- Chorea: consisting of involuntary, jerky, rapid movements and dementia
Cervical Plexus Emerges
C1 - C4 // deep to SCM
Cervical Plexus Innervates
- Cutaneous sensory information from posterior scalp to clavicle
- Motor innervation of neck/diaphragm (Phrenic nerve)
Brachial Plexus Emerges
Anterior rami of C5-T1 between ant/mid scalene muscles, passes deep to clavicle and enter axilla
- Distal axilla, plexus becomes - radial, axilla, ulnar, median, musculotaneous
Brachial Plexus Innervates
Entire UE
Lumbar Plexus Emerges
Anterior rami of L1-L4 and forms in psoas muscles
Lumbar Plexus Innervates
Skin/muscles of anterior/medial thigh
- Cutaneous branch, medial leg/foot
Sacral Plexus Emerges
Sacrum
Sacral Plexus Innervates
Posterior thigh and most of leg/foot
Characteristics associated with autonomic dysreflexia
Abrupt increase in BP and pounding headache
Symptoms of vestibular dysfunction
- Pt report dizziness are often describing different experiences
Vertigo - illusion of movements
Near syncope - feeling of impending faint
Dysequilibrium - loss of balance
Light headedness - inability to concentrate
Hallpike Maneuver
Designed to provoke maximal movement of otoconia in posterior semicircular canals as diagnostic tests for Benign Paroxysmal Postitional Vertigo (BPPV)
- If elicits nystagmus and vertigo after few seconds of latency indicates otoconia in horizontal semicircular canal
Myasthenia Gravis
Autoimmune disorder where antibodies destroy nicotinic receptors on muscle cells (CNS)
- Normal levels of ACh released, but not enough receptors to bind with at neuromuscular joint
- Slowly progressive
- Worsens throughout day
S/S of Myasthenia Gravis
Ptosis, proximal limb weakness, dysarthria, dysphagia
Guillian Barre Syndrome
Autoimmune disorder that attach Schwann cells which leads to demyelination of peripheral motor/sensory neurons
- Rapid onset, gradual recover
- Severe fatigue
S/S of Guillian Barre Syndrome
- Decreased sensation
- Muscle paralysis
- Distal to proximal symmetric progression
