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2971 Lab Neuro

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2971 Lab Week 5 Neuro

A&P

Macrostructure
  1. Scalp-moves freely. Protects and cushions from injury
  2. Skull-rigid, bony cavity. Fixed volume=1500 ml


Meninges (protective membranes)
  1. Dura mater-thick, tough and outermost
  2. Arachnoid mater-arachnoid villa project into the subarachnoid space to absorb
      CSF
  3. Pia mater-thin and vascular; helps form the choroids plexuses, which are vascular
      structures in the ventricles that form CSF.

CNS
Composed of brain and spinal cord.
4 components of the brain:
    1. Cerebrum-largest portion containing corpus callosum, cerebral cortex, basal
       ganglia and each hemisphere is divided into 4 lobes: frontal, parietal, temporal
       and occipital
    2. Diencephalon-relay center composed of the thalamic structures: thalamus,
       epithalamus and the hypothalamus important in body temp regulation, pituitary
       hormone control and ANS response; and has a role in behavior via limbic system.
    3. Cerebellum-inferior to occipital lobe and behind the brain stem. Responsible for
       coordination of movement. It has 2 lobes and medial part called vermis which
       maintains posture and equilibrium.
    4. Brain stem-midbrain, pons and medulla oblongata. Reticular formation controls
       resp, cardio and vegetative functions. RAS is excitatory responsible for arousal,
       and perception of sensory input. Contains CN III-XII nuclei. Medulla oblongata
       center for reflexes and resp and cardio system
Spinal Cord-continuation of medulla oblongata. Dorsal horn contains sensory (afferent)
neurons; ventral horn contains motor (efferent) neurons.

Motor Pathways of the CNS
3 motor pathways:
   1. Pyramidal Tract or corticospinal pathway descends from the motor area of the
       cerebral cortex, through the midbrain, the pons and the medulla. Contains upper
       and lower neuron cell bodies. Lower motor neurons innervate skeletal muscle
       and responsible for purposeful, voluntary movement.
   2. Extrapyramidal Tract-includes all motor neurons not included in the pyramidal
       tract. Responsible for controlling gross movements and muscle tone.
   3. Cerebullum
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Sensory Pathways of the CNS
Afferent neurons divided into somatic afferent (skeletal muscles, joints, tendons and skin)
and visceral afferent neurons (viscera).

Spinothalamic tracts
   1. lateral-pain and temperature sensations
   2. anterior-crude or light touch

Posterior Column-carries position, vibration, and fine touch.

BLOOD SUPPLY
Internal carotid and vertebral arteries meet at circle of Willis.

Peripheral Nervous System
   1. Spinal verves-31 pairs which each innervate a specific dermatome
   2. Cranial Nerves-12 pairs
   3. ANS-sympathetic contains fight or flight actions; parasympathetic does general
      housekeeping.

Reflexes
No conscious control. Three categories:
   1. muscle stretch or DTR
   2. Superficial reflexes
   3. Pathological reflexes

ASSESSMENT OF THE NEUROLOGICAL SYSTEM

Mental Status
Assess physical appearance and behavior, communication, LOC, cognitive abilities and
mentation.
As the pt approaches observe gait, posture and mode of dress, involuntary movements,
voice, etc.

Physical Appearance and Behavior
Posture-relaxed, slumped or stiff
Patience
Movements-control and symmetry
Gait

Dress, Grooming and Personal Hygiene
Clean, condition, age and weather appropriate
Grooming for adequacy, symmetry and odor

Facial Expression
Appropriate variations and symmetry
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Affect
Verbal and nonverbal behavior- note if labile, blunted or flat and extremes

Communication
Voice quality (volume and pitch)
Articulation-fluency and rate
Follows commands
Ability to write-spelling, grammar and logical thought process

Aphasia=impairment of language function
Dysarthria=disturbance in muscle control of speech
Dysphonia=difficulty with laryngeal sounds
Apraxia=inability to convert intended speech into motor act of speech
Agraphia=loss of writing ability
Alexia=inability to grasp meaning of written words

LOC
RAS
Glascow Coma Scale

Cognitive Abilities and Mentation
MMSE-p621

Attention
Serial 7 or 3

Memory
Ask name of spouse, pt’s BD, president’s name, mother’s maiden name

Judgement
Insight
Spacial Perception
Pt copies previously drawn simple figures, identifies familiar sounds, id’s right from left
body parts.
Agnosia=inability to recognize form and nature of objects or persons
Apraxia=inability to perform purposeful movements
Constructional apraxia=inabilitly to reproduce figures on paper

Calculation
Dyscalculia=inability to perform calculations

Abstract Reasoning
Thought Process and Content
Thought process should be logical, coherent, and goal oriented and reality based.
Confabulation=making up of answers unrelated to facts
Echolalia=involuntary repetition of words
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Neologism=word meaningful only to pt

Suicidal Ideation
Have you ever felt so bad you wanted to hurt yourself? Now?
PT should be able to verbalize self worth

Mental Health

Sensory Assessment
Exteroceptive Sensation-expose legs, arms and abdomen.

Light Touch-cotton wisp with very light strokes distal to proximal
Superficial pain—sharp or dull

Temperature

Anesthesia=absence of touch sensation
Hypesthesia=diminished sense of touch
Paresthesia=numbness, tingling
Dyesthesia=abnormal interpretation
Analgesia=insensitivity to pain
Hypalgesia=diminished sensitivity to pain
Hyperalgesia=increased sensitivity to pain

Proprioceptive Sensation
   1. Motion and Position (up and down of body part
   2. vibration Sense-use tuning fork over bony prominences

Cortical Sensation
   1. Stereognosis-ability to ID objects by manipulating and touch.
       Astereognosis=inability to recognize nature of objects
   2. Graphesthesia-ability to ID numbers, letters or shapes drawn on the skin
       Graphanesthesia=inability to recognize a number or letter drawn on the skin.
   3. Two-Point discrimination (pt should be able to discriminate sharp objects 5 mm
       apart on fingertips.
   4. Extinction-Touch opposite sides of the body at same site and ask if felt; then
       remove one side and ask where the sensations are felt..

CN
           I.     Olfactory Nerve-ID smells, alternate left and right nostrils
                  Anosmia=loss of sense of smell
           II.    Visual acuity, visual fields, funduscope eval
           III.   Oculomotor-cardinal fields of gaze, eyelid elevation, Pupil reactions
           IV.    Trochlear-cardinal fields of gaze
           V.     Trigeminal-a.motor-contraction of temporalis and masseter
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                                b.sensory-cotton wisp sensation ophthalmic, maxillary and
           mandibular.; pain sensation, temperature sensation, blink reflex
           VI.      Abducens-cardinal fields of gaze
           VII. Facial a. motor-symmetry of face
                           b.sensory-taste tip=sweet, salty and sour; borders are sour, back
and soft palate are bitter
Ageusia=loss of taste
Hypogeusia=diminution of taste

           VIII. Acoustic- a. Coclear divisionhearing, Weber and Rinne
                           b. Vestibular Division-vertigo and nystagmus
           IX and X.-Glossopharyngeal and Vagus-soft palate and uvula and gag reflex,
           swallow.
           XI.    Spinal Accessory-turn head with resistance, shrug shoulders
           XII. Hypoglossal-tongue movements and lingual sounds


MOTOR SYSTEM
Decerebrate rigidity
Decorticate rigidity
Pronator Drift-have pt extend arms out in front with arms out in front, palms up for 20
sec.

Cerebellar function
Smooth, precise, and harmonious muscular activity

Incoordination is categorized into 3 different types:
   1. cerebellar
   2. vestibular
   3. posterior column syndromes

COORDINATION
1.Index finger to nose, alternate index finger to nose, then with eyes closed
2. Touch finger to nose, have pt touch your index finger-start 18 inches away then change
rapidly; have pt change hands.
3. Rapid alternating movements-pat knees palms up then down rapidly alternating
    4. Have pt touch thumb to each of the fingers of the hand; repeat other hand
    5. Heel shin slide
    6. Draw figure 8 with a foot, repeat other foot
    7. Tap each foot by rapidly extending

dyssynergy=lack of coordinated action
Dysmetria=impaired judgement of distance, range, speed and force of movement
dysdiadochokinesia=inability to perform rapidly alternating movements
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GAIT
   1.   Have pt walk on toes, then heels
   2.   Tightrope walk with arms at sides
   3.   Hop in place on one foot and then on the other
   4.   Romberg’s test-stand with feet together, arms at sides first eyes open then closed

REFLEXES
Pt should be relaxed and comfortable. Position so that extremities are symmetrical.
DTR grading:
0=absent
+1=present but diminished
+2=normal
+3=mildly increased but not abnormal
+4=markedly hyperactive, clonus may be present

BICEPS
Flex arm to between 45-90*
Place thumb firmly on the biceps tendon just above the crease of the antecubital fossa.

BRACHIORADIALIS
Flex arm to 45*
Tap brachioradialis above the styloid process of the radius

TRICEPS
With pointed end of reflex hammer tap triceps just above its insertion above the
olecranon process.

PATELLAR
Place hand over quads to feel contrax, tap patellar tendon just below patella

ACHILLES
Slightly dorsiflex the patient’s foot
Tap Achilles tendon just above the insertion point.

SUPERFICIAL REFLEXES
ABDOMINAL
Upper
With pt in recumbent position, arms at sides, and knees slightly bent; use tip of cotton
applicator to stimulate the skin by stroking in a diagonal downward and inward direction.
Lower abd reflex
Stimulate area below the umbilicus, stroke in diagonal downward and inward to the
symphysis pubis.

PLANTAR
Stroke outer aspect of the sole of the foot from heel across to just below the great toe.
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CREMASTERIC
Male patient should be lying down with thighs exposed and testicles visible; stroke skin
of inner aspect of the thigh near the groin from above downward.

BULBOCAVERNOSUS
Pinch skin of the foreskin or the glans penis and observe for a contraxion of the
bulbocavernosus muscle in the perineum at the base of the penis.

PATHOLOGICAL REFLEXES
GRASP
SNOUT-tap upper or lower lip and observe for a puckering of the lips (abn after infancy)
GLABELLAR-tap on the forehead with finger between the eyebrows and watch for a
hyperactive blinking response. (Parkinson’s disease and glioblastoma of the corpus
callosum)
BRUDZINSKI’S SIGN-Flex neck in a deliberate motion. Abnormal if leg(s) flex.

GERONTOLOGICAL VARIATIONS

Depression is associated with decreased levels of norepinephrine.

Total brain weight, number of synapses, and number of neurons diminish with age
beginning at age 50.

Elderly have decreased visual acuity, visual fields, color sensitivity, papillary size and
diminished papillary response to light.
Hearing also diminishes due to ossification of the ossicles and degenerative changes in
the auditory nerve.
Elderly also demonstrate difficulties with balance and changes in coordination and
equilibrium.

Cognitive changes include decreased memory, primarily short-term memory, increased
learning time, changes in affect, mood and orientation.

				
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posted:4/23/2010
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