NeuroPhys Unit 1

  1. Layers of Meninges
    • Dura Mater
    • -2 layers of fibrous connective tissue
    • Arachnoid Mater
    • -Subdural space under the dura mater
    • Pia Mater
    • -Delicate, clings to the brain
  2. Role of Meninges
    • Protection
    • Blood brain barrier
    • -Glucose, amino acids, electrolytes, fats and fat-soluble molecules move freely
    • -Toxins, wastes, etc. do not
  3. Frontal lobe functions
    Executive functions; high order functions
  4. Parietal lobe functions
    • Somatosensory
    • Initial processing of tactile and proprioceptive info
    • Comprehension of language (works with temporal lobe)
    • Spatial orientation and perception (a secondary role)
  5. Temporal lobe functions
    • Primary auditory cortex (Wernicke's Area)
    • Visual association cortex - Higher order processing of visual info
    • Includes Hippocampus and Amygdala (learning and memory)
  6. Occipital lobe functions
    • Primary visual cortex
    • Visual association cortex - high order processing of visual info (extends into temporal lobe)
  7. Limbic lobe function
    • Cingulate Gyrus and structures connected make up the Limbic System
    • Emotional responses
    • Memory
  8. Insula function
    • Gustatory (taste)
    • Autonomic
    • Pain
    • Emotional responses (to pain?)
    • Language?
  9. Cerebellum function
    • Receives info on body position and muscles tension and visual input
    • Coordinated muscles; sends info to cerebral motor cortex
    • Also sends stimulus to the midbrain and thus the spinal cord
  10. Cerebellum lobe functions
    • Anterior lobe: leg movement coordination
    • Flocculonodular lobe: input from vestibular system; controls eye movements and postural adjustments to gravity
    • Posterior lobe: voluntary movements
  11. Hypothalamus
    • Autonomic, endocrine, emotional and somatic functions
    • Promotes homeostasis
  12. Medulla
    • vital functions - regulates blood glucose, salivation, vomiting, sneezing, coughing, and cardiovascular and respiratory functions
    • Most sensory and motor tracts run through this
  13. Fornix
    relays info to/from Hippocampus
  14. Cingulate Gyrus
    • Upper portion of limbic system
    • Helps regulate emotions and pain
    • Drives the body's conscious response to unpleasant experiences
    • Involved in fear and prediction (and avoidance) of negative consequences
  15. Thalamus
    Gateway to cortex; relay for sensory input
  16. Pineal body
    • Secretes melatonin
    • Role in sleep-wake cycle and sexual behavior
  17. Midbrain
    Visual reflexes, auditory relay, startle reflex, releases dopamine, limb flexion
  18. Pons
    Transmits nerves from medulla oblongata to cerebrum, cerebrum to the cerebellum, and peripheral nerves to higher functions
  19. Cerebral Peduncle of brain stem
    Made of corticospinal, corticobulbar, and corticopontine fibers traveling base of midbrain
  20. Superior colliculus of brain stem
    • Receives afferents from retina and visual cortex
    • Role in directing visual attention and eye movements
  21. Inferior colliculus
    Link to auditory system - sends fibers to medial geniculate nucleus
  22. Ventricles
    • Generate CSF
    • Contain Cerebral Aquaduct = narrow channel that connects 3rd and 4th ventricles
  23. Cerebrospinal Fluid (CSF)
    • Protects the CNS - absorbs impact of injury
    • Supplies water, amino acids, ions and chemical messengers, nutrients and removes metabolites from brain
    • Formed in ventricles in Choroid Plexus
  24. Basal Ganglia
    • Group of nuclei that includes the Caudate Nucleus, Putamen, Globus Pallidus, and Substantia Nigra
    • Initiation and coordination of movements
  25. Caudate Nucleus
    • Associated with prefrontal area
    • Mostly involved in cognition
  26. Putamen
    Motor functions of Basal Ganglia
  27. Globus Pallidus
    • Inhibitory axons to thalamus
    • Major output structure of Basal Ganglia
  28. Mammillary body
    Recollective memory and relay for impulses coming from the amygdala and hippocampi to the thalamus
  29. Subthalamus
    • Part of motor system
    • Correlation center for optic and vestibular impulses relayed to the globus pallidus
  30. Substantia Nigra
    • Contains dopaminergic neurons
    • Involved in motor control
  31. Amygdala
    • Connects to hypothalamus
    • Regulates endocrine activity, sexual behaviors, food and water intake, and fear and aggression responses
  32. Hippocampus
  33. Lateral Geniculate Nucleus
    relays info for vision to thalamus and then to Occipital lobe
  34. Medial Geniculate nuclei
    relays auditory info to thalamus and then temporal lobe
  35. Corpus callosum
    connects hemispheres
  36. Corticospinal tract
    • Fibers form sensorimotor cortex
    • Initiate movement, skilled volitional movement, modulate ascending systems
  37. Rubrospinal tract
    • Project to spinal motor neurons
    • Motor control; but over time, role has been replaced by Corticospinal tract
  38. Tectospinal tract
    • Guide head movements - activate cervical spinal circuits that control neck and back muscles
    • Keep us upright - extensors of legs
  39. Vestibulospinal tract
    moves head in response to stimulus
  40. Reticulospinal tract
    • Pontine = leg extension (antigravity)
    • Medullary = releases antigravity muscles to move
  41. Dorsal columns
    Carry touch and proprioception info to brain stem
  42. Spinothalamic tract
    Convey pain and temp to thalamus
  43. Neuron levels
    • Primary (first order) neuron
    • -Receptor to CNS (DRG or equivalent)
    • Secondary (second order) neuron
    • -One level of CNS to thalamus
    • Tertiary (third order) neuron
    • -Thalamus to cortex
  44. Upper motor neuron
    Motor cortex and motor tracts that descend into the cord
  45. Lower motor neuron
    Alpha motor neuron to muscle or autonomic motor
  46. Frontal lobe damage
    • Apathy and indifference
    • Spoken language
    • Poor problem solving
    • Memory loss
    • Personality changes
    • Antisocial behavior
    • Disinhibition
    • Motor impairments
  47. Parietal lobe damage
    • Loss of sensation
    • Cant comprehend language
    • Hemi-neglect = more common with right lesion
    • Perceptual deficits
  48. Temporal lobe damage
    • Comprehension of language
    • Auditory issues
    • Learning and memory
    • Lowest threshold for seizure activity
  49. Occipital lobe damage
    visual impairments
  50. Limbic lobe damage
    • Emotional impairments
    • -Recognizing danger
    • -Expression of emotions
    • Memory
  51. Cerebellar lobe damage
    • Coordination
    • Balance
    • Vestibular issues
  52. CVA
    Death of brain cells due to lack of oxygen resulting from blocked or ruptured vessels (hemorrhagic or ischemic)

    • Transient Ischemic Attack (TIA)
    • Short term blockage of blood flow
    • Damage isn't permanent; symptoms last less then 24 hrs
    • Warning for a risk for major CVA
  53. Hemorrhagic strokes
    • Result of rupture of weakened blood vessels in brain
    • Includes Aneurysm (ballooning of blood vessels) and Arteriovenous Malformation (AVM; abnormally formed blood vessels)
  54. Intracerebral Hemorrhage (ICH)
    • Bleeding within the brain tissue
    • Life threatening
    • Causes
    • hypertension
    • arteriovenous malformations
    • head traumas
  55. Subarachnoid Hemorrhages (SCH)
    • Bleeding in space between Pia Mater and Arachnoid membrane
    • Causes
    • Head trauma most common
    • Cerebral aneurysms, Arteriovenous Malformation, and Hypertension
  56. Ischemic strokes
    • Blockage of blood vessel supplying blood to brain
    • Cerebral Thrombosis
    • -Blood clot that develops at the site of the vessel
    • Cerebral Embolism
    • -Blood clot the develops at larger arteries and travel to blood vessels of the brain
  57. Initial signs and symptoms of a stroke
    • Sudden one sided weakness (limbs and facial droop)
    • Visual Changes
    • Confusion
    • Sensory changes
    • Trouble producing language or comprehending speech
    • Headache
    • Balance problems

    • FAST
    • Face
    • Arms
    • Speech
    • Time
  58. Right CVA
    • Full communication
    • Left sided weakness/dysfunction
    • Impaired judgement
    • Denial
    • Impulsiveness
    • Impaired attention
    • Inappropriate socialization/behavior
    • Problems with non-verbal communication
    • May be seen as uncooperative, unmotivated, overly dependent
    • Spatial perceptual deficits
    • Left neglect
    • Left inattention
  59. Left CVA
    • Aphasia (loss of ability to speak or interpret written or spoken word)
    • Difficulty swallowing
    • Slow movements
    • Decreased initiation of/cautious movements
    • Lack of motor planning or proper use of items (Apraxia)
    • Rarely have right neglect or inattention
  60. Thalamic CVA
    • Responsible for relaying sensation, motor signals, and spatial sense
    • Symptoms
    • Hearing noises
    • Feeling ear pressure on opposite side
    • Pain in opposite side of body (most common)
  61. Pusher syndrome
    • Due to Posteriolateral Thalamus CVA
    • Exhibit tendency to push away from the noninvolved side
  62. Brain Stem Stroke
    • Midbrain
    • Visual reflexes
    • Auditory relay
    • Startle reflex
    • Releases dopamine
    • Limb flexion
    • Pons
    • Transmits nerves from medulla and cerebrum, and from cerebrum to the cerebellum
    • Medulla
    • Sends ascending impulses through the brain stem and to higher functions
    • Controls heart rate
    • Vasomotor control
    • Respiratory center
  63. Brain Stem Damage: Coma
    • No/limited response to stimulus
    • May have spontaneous body movements
    • Cause: Reticular Activating System
  64. Primary clinical features of brain tumors
    *Due to increased ICP

    • Headaches
    • Nausea
    • Drowsiness
    • Seizures
    • -Blocked or abnormal electrical signals
  65. Secondary features of brain tumors
    *Depends on lobe/structures impacted

    • Paralysis
    • Memory and cognitive disorders
    • Speech disorders
    • Ataxia, dysarthria, apraxia
    • Hormonal changes
    • Etc.
  66. Treatment side effects of brain tumors
    • Fatigue
    • Memory and cognitive changes
    • Seizures
  67. Meningiomas
    • Most common primary brain tumor
    • Arise from meninges

    • Symptoms/side effects
    • Weakness in limbs
    • Personality change
    • Low vision problems
    • Depends on location
  68. Meningitis
    • Inflammation in meninges of brain and spinal cord
    • Infection in fluid surrounding brain and spinal cord
    • CSF becomes thickened; causes blockage of ventricles
    • Can lead to hydrocephalus or encephalitis

    • Causes
    • Viral infection
    • Bacterial infection
    • Chemical irritation
    • Drug allergies
    • Fungi
  69. Encephalitis
    • Inflammation of the brain
    • Usually occurs in first year of life; most severe in young and elderly

    • Transmission
    • Saliva
    • Nasal discharge
    • Feces
    • Respiratory secretions
    • Throat secretions

    • Causes
    • Viral infection most common
    • Bacterial infection
  70. Hydrocephalus
    Imbalance between how much CSF is produced, how much is absorbed into blood stream, and abnormal flow from brain to SC

    • Contributing factors
    • Congenital
    • Lesions or tumors
    • CNS infections
    • Bleeding in brain from stroke or head injury
    • Other traumatic injury to brain
  71. Hydrocephalus treatment
    • Shunt replacement 
    • -Insertion of a catheter into the 3rd ventricle
    • Pleural, peritoneal, or atrial drainage
  72. Paraneoplastic Syndromes
    • Group of rare disorders that develop in some people with cancer
    • Rare
    • Can affect any organ or tissue; nervous system itself is a common site
    • Caused by typical cancers
    • -Occur when the cancer fighting agents of the immune system attack nerve cells
  73. Treatment of Paraneoplastic syndromes
    • Treat the cancer
    • Suppress immune response causing the neurological signs
    • Medication 
    • Immunosuppression by intravenous immune globulin
    • Plasmapheresis
    • -Remove plasma containing unwanted antibodies
  74. Mild vs Severe TBIs
    • Mild
    • Loss of consciousness for less than 30 minutes
    • Severe
    • Loss of consciousness longer than 30 minutes as well as loss of memory
    • Irreversible brain damage
  75. Causes of TBIs
    • Penetrating (open)
    • Bullet or shrapnel
    • Stab wound
    • Skull fragment

    • Closed
    • Blow to head
    • Falls
    • Car accidents
  76. Hematomas
    • Epidural
    • Damage to middle meningeal artery by a fracture to the temporal bone
    • Subdural
    • Damage to veins between cortex and dural sinuses from falls or car crashes
    • Intracerebral
    • Results from merging of contusions
  77. Coup-Contracoup injuries
    Damage to impact site and opposite side of brain as well
  78. Diffuse axonal injury
    • Damage throughout brain due to rotational/shearing effects
    • Influx of calcium
    • Cytoskeletal collapse disrupts transmissions
    • Axon swells and breaks
    • Distal axon degenerates

    Primarily affects basal ganglia, superior cerebellar peduncle, corpus callosum, and midbrain
  79. Diffuse axonal injury pathology
    • Primary tissue damage from injury itself
    • Secondary due to chemical process response of brain to injury 
    • -Impaired regulation of cerebral blood flow
    • --Increased lactic acid, membrane permeability, and edema
    • -Impaired metabolism
  80. Cerebral Vasospasm pathology
    Chronic depolarization due to reduced K+ channel activity in blood vessels
  81. Cerebral oxygenation pathology
    • Balance between delivery and consumption of cerebral oxygen can indicate severity of injury
    • Critical threshold of oxygen pressure before neurons begin to die
    • -15-10mm Hg PtO2
  82. Excitotoxicity pathology
    • Massive release of excitatory amino acid neurotransmitters
    • Glutamate
    • -Affects neurons, astrocytes, and causes overstimulation of glutamate receptors
    • --Release of Ca2+, Na+, and K+
    • --Breakdown of blood brain barrier
    • --Increased metabolic demand
  83. Edema pathology
    • Dangerous in a closed brain injury
    • Pressure prevents blood flow and oxygen from getting to brain
  84. CN l: Olfactory nerve
    • Sensory only
    • Smell
    • Lesions cause loss of smell (anosmia) or taste
    • Test with Pocket smell test or other familiar aromas
  85. CN ll: Optic nerve
    • Sensory only
    • Vision
    • Test with standard vision tests
    • Pathology often results in blindness
  86. Damage to Medial Optic Chiasm
    • Compromise the decussating fibers from both nasal hemiretinas
    • Loss of peripheral vision in both eyes = Bitemporal Hemianopia
  87. Damage to lateral aspect of optic chiasm
    Affects the fibers of the ipsilateral nasal hemiretina
  88. Damage to posterior optic chiasm
    • Half of the ganglion cell axons projecting to the LGN decussate in the optic chiasm
    • Loss of input from contralateral visual fields of both eyes (homonymous hemianopia)
  89. Damage to the optic tract
    Loss of contralateral visual fields in both eyes (homonymous hemianopia)
  90. Damage to the optic radiation
    • Fibers of the optic radiation are considerably more spread out than those of the optic tract
    • Damage normally only occurs to a portion of the geniculocalcarine tracts
  91. CN lll: Oculomotor nerve
    • Eye and eyelid movement
    • -Superior rectus, inferior rectus, medial rectus, inferior oblique, levator palpebrae superioris
    • Autonomic - parasympathetic (pupillary constrictor)
  92. Oculomotor nerve lesions
    • Compressive lesions are peripheral; usually dilate the pupil
    • Ischemic lesions affect central portion of nerve and don't dilate
    • If completely paralyzed, eyes will deviate to lateral
    • Ptosis: eyelid droop
  93. Oculomotor nerve testing
    • Look for ptosis
    • Test extraocular range of motion (H pattern)
    • Test pupillary constriction with the light reflex
  94. CN lV: Trochlear Nerve
    • Motor only
    • Moves eye downwards and outward (superior oblique muscle)
  95. Trigeminal nerve
    • Sensory and motor
    • 3 branches
    • Ophthalmic
    • Motor - eyeball, tear gland
    • Sensory - eye lining, brow forehead
    • Maxillary
    • Motor - muscles of temple
    • Sensory - side of forehead, cheek, mouth membranes, lower eyelid
    • Mandibular 
    • Motor - chewing muscles, salivary glands, anterior 2/3 of tongue
    • Sensory - teeth and gums of jaw, external ear, temple, tongue (not taste)
  96. Trigeminal nerve palsy symptoms
    • Anesthesia to half of the face
    • Inflammation of cornea
    • Chewing muscles paralyzed
  97. Trigeminal nerve corneal reflex test
    • Touch cornea with cotton wisp
    • Immediate closure of both eyelids should occur
  98. Trigeminal nerve sensory testing
    • Tough face with a piece of cotton and a safety pin
    • Positive test if impaired or absent sensation or inability to differentiate
  99. Trigeminal nerve motor testing
    • Patient performs mandibular protrusion, retrusion, and lateral deviation
    • Positive test if impaired ability to move mandible through the specific motions
  100. Trigeminal nerve masseter reflex
    Pronounced jaw jerk reflex when mandible is tapped at a downward angle
  101. CN Vl: Abducens nerve
    • Motor only
    • Lateral rectus
  102. CN Vll: Facial nerve
    • Sensory and motor
    • Controls most facial expressions
    • Secretion of tears and saliva (all glands of head except parotid)
    • Sensory for ear and tympanic membrane
    • Special sensory - taste, anterior two thirds of tongue
    • Bell's Palsy - often is self-correcting
  103. Facial nerve motor testing
    • Wrinkle forehead and compare the two sides
    • Shut eyelids and try to pry both open; compare
    • Smile and compare both sides
    • Purse lips or whistle
  104. Facial nerve sensory testing
    Pt is asked to distinguish between sweet and salty placed on the anterior portion of the tongue
  105. CN Vlll: acoustic/vistibulocochlearnerve
    • Sensory only
    • Hearing and balance
    • Aspirin, streptomycin and quinine can damage auditory nerve and cause bilateral hearing loss
    • Compression due to blood causes temporary deafness; permanent deafness results from acute compression
  106. Acoustic/Vestibulocochlear nerve testing
    • Distance from ear where patient can hear a ticking watch
    • Positive by inability to hear at 18-24 inches or a significant bilateral difference
  107. Acoustic/Vestibulocochlear Rinne's test
    • Vibrating tuning fork is placed on the mastoid process, and then quickly around the ear hold
    • Sound should be louder next to the ear hole
  108. Acoustic/Vestibulocochlear Weber's test
    • Vibrating tuning fork placed against the middle of forehead
    • Sound should be equally audible in both ears
  109. CN lX: Glossopharyngeal
    • Sensory and motor
    • Posterior 1/3 of tongue and pharynx
    • Motor to Stylopharyngess muscle and parotid gland
    • Taste and swallowing
    • Sensory for internal surface of tympanic membrane and carotid body
    • Injury causes loss of sour and bitter taste and impaired swallowing
  110. Glossopharyngeal nerve motor testing
    • Tough pharynx with a tongue depressor
    • Lack of gagging may be a positive sign
  111. Glossopharyngeal sensory testing
    • See if patient can taste, especially sour and bitter, on posterior 1/3 of tongue
    • Also inability to feel tongue depressor touch back of throat
  112. CN X: Vagus nerve
    • Sensory and motor
    • Muscles of pharynx/larynx
    • Parasympathetic motor to neck, thorax, abdomen
    • Sensory from pharynx/larynx/viscera

    Clinical presentation is hoarseness, difficulty swallowing
  113. Vagus Nerve testing
    • Positive if unable to feel or lack of gagging when a depressor touches the pharynx
    • If absent; uvula will deviate from lesion or not elevate if bilateral
  114. CN Xl: Spinal Accessory Nerve
    • Motor 
    • Some laryngeal muscles and some muscles of back and neck
    • Hyperactivity causes torticollis
  115. Spinal accessory nerve testing
    Positive if Inability to shrug shoulders against resistance or turn head back to center against resistance
  116. CN Xll: Hypoglossal nerve
    • Motor only
    • Positive test if pt can't fully protrude tongue or tongue deviates to the week side
    • Test speech - have patient repeat a phrase with lots of r's in it or say la la la
  117. Damage (stroke) to anterior cerebral arteries
    • Cortical branches
    • Personality changes
    • -Flat, impulsive, confused, inactive, perseverative, cognitive probs
    • -Contralateral Hemiplegia and sensory loss
    • Deep branches
    • Motor dysfunction
  118. Middle Cerebral artery damage
    • Optic tract - homonymous hemianopia
    • Sensorimotor cortex - contralateral hemiplegia and sensory loss
    • Dominant/Left Hemisphere - language impairment, apraxia, cautious
    • Nondominant Hemisphere - spatial relationships, neglect, nonverbal communication, distracted, poor judgement, impulsive
    • Deep branches - contralateral hemiplegia affecting extremities and face equally
  119. Posterior cerebral artery damage
    • Midbrain branches
    • Contralateral hemiparesis
    • Eye movement paresis/paralysis - double vision 
    • Cortical blindness
    • Deep branches
    • Thalamic syndrome - severe pain, contralateral hemisensory loss, flaccid hemiparesis
    • Hippocampus - declarative memory
  120. Carotid Artery Occlusion
    • Damage = TIA
    • Atherosclerosis is one of the main risk factors for ischemic CVA
    • Contralateral weakness and/or sensory disturbance, ipsilateral blindness, and dysphasia, aphasia, or speech apraxia
    • Cognitive impairment and decline
  121. Anterior Choroidal Arteries
    • Supply structures in the cerebrum
    • Damages
    • Hemiplegia on contralateral side
    • Contralateral hemihypesthesia
    • Homonymous hemianopia
  122. Basilar Artery
    • Supplies brainstem
    • Damage - complete occlusion is death
  123. Hypoxia/Anoxia
    Diminished/lack of oxygen to brain

    • Symptoms
    • Loss of consciousness or coma
    • Persistent vegetative state
    • Resemble TBI
  124. Hypoxia/Anoxia cognitive impairments
    • Short term memory loss
    • -Hippocampus is very sensitive to lack of oxygen
    • Poor executive functions
    • -judgement making, reasoning, and processing info
    • -impulsive and indecisive
    • -lack ability to concentrate or focus on more than one task
  125. Cerebral Aneurysm
    • Weak point in blood vessel in brain
    • Can rupture

    • Causes
    • Trauma
    • Infection
    • Hardening of arteries
    • Congenital (most)
  126. Cerebral Aneurysm treatment
    • Prior to rupture may do lumbar puncture
    • May do nothing
    • May clip or remove it
    • May insert coils to block it off
  127. ArterioVenous Malformation (AVM)
    • abnormal collection of blood vessels
    • Lack the tiny capillaries
    • Blood does not go to the tissues but is pumped through the shunt and back to the heart without ever giving nutrients to the tissues
    • Risk of rupture and a stroke
Card Set
NeuroPhys Unit 1
NeuroPhys Unit 1