Nervous System Flashcards
What are the twelve cranial nerves?
CN I (olfactory) CN II (optic) CN III (oculomotor) CN IV (trochlear) CN V (trigeminal) CN VI (abducens) CN VII (facial) CN VIII (vestibulococchlear) CN IX (glossopharyngeal) CN X (vagus) CN XI (accessory) CN XII (hypoglossal)
What is the function of the Olfactory Nerve (CN I)?
sense of smell
What is the function of the Optic Nerve (CN II)?
vision
What is the function of the Oculomotor Nerve (CN III)?
- pupillary constriction
- opening the eye
- most EOMs
What is the function of the Trochlear Nerve (CN IV)?
inferior and medial movements of the eye
What is the function of the Trigeminal Nerve (CN V)?
- motor: temporal and masseter muscles, lateral pterygoids
- sensory: facial (ophthalmic, maxillary, and mandibular divisions)
What is the function of the Abducens Nerve (CN VI)?
lateral deviation of the eye
What is the function of the Facial Nerve (CN VII)?
- motor: facial movements and expressions (closing eye and mouth)
- sensory: taste on the anterior 2/3 of tongue
What is the function of the Vestibulocochlear Nerve (CN VIII)?
- hearing (cochlear division)
- balance (vestibular division)
What is the function of the Glossopharyngeal Nerve (CN IX)?
- motor: pharynx
- sensory: posterior portions of TM and ear canal, pharynx, posterior tongue (including taste), uvula
What is the function of the Vagus Nerve (CN X)?
- motor: palate, pharynx, larynx, uvula
- pharynx and larynx
What is the function of the Accessory Nerve (CN XI)?
- motor: SCM and upper portion of trapezius
What is the function of the Hypoglossal Nerve (CN XII)?
- motor: tongue
What are the aspects of the Mental Status Examination (MSE)?
- appearance and behavior
- speech
- affect
- mental content
- mental function
- judgment
- insight
- suicidal and homicidal risks
What are the components of Appearance and Behavior in the MSE?
- level of consciousness
- posture and motor behavior
- dress, grooming and personal hygiene
- facial expression
- manner
- relationship to people and things
What are the components of Speech in the MSE?
- quantity: talkative vs silent
- rate: fast vs slow
- volume: loud vs soft
- articulation of words
- fluency: look for hesitancies, disturbed inflections (monotone), circumlocations (word substitutions)
What are the components of Affect in the MSE?
- observable, usually episodic, feeling or tone expressed through voice, facial expression, and demeanor
What are the components of Mental Content in the MSE?
- what pt thinks about
- included level of insight and judgment
What are the components of Mental Function in the MSE?
assessed by vocab, fund of info, abstract thinking, calculations, construction of objects that have 2 or 3 dimensions
What are the components of Judgment in the MSE?
- process of comparing and evaluating alternatives when deciding on a course of action
- reflects values that may or may not be based on reality and social conventions or norms
What are the components of Insight in the MSE?
- awareness that symptoms of disturbed behaviors are normal or abnormal
- ability of pt to understand and acknowledge their illness or situation
What are the components of Suicidal/homicidal Risks in the MSE?
- ask direct questions
- depression is twice as common in women and is a frequent complaint of chronic medical illness
- screen high-risk patients for early signs of depression that are often missed: low self-esteem, loss of pleasure in daily activities, sleep disorders, difficulty concentrating or making decisions
What are the levels of consciousness? (5)
- alert: pt able to open eyes, look at you, respond fully and appropriately
- lethargic: drowsy but can open eyes, look at examiner and respond; falls back to sleep easily
- obtunded: opens eyes and looks at you; offers confused responses, has lack of interest in the environment
- stuporous: wakens only with painful stimuli; verbal responses slow or absent; unresponsive unless stimuli is present
- comatose: unarousable to any stimuli; GCS
What is decorticate posture?
- upper extremities flexed at elbows and held closely to body
- lower extremities internally rotated and extended
- thought to occur when brain stem is not inhibited by motor function of cerebral cortex
What is decerebrate posture?
- pts with extensive brain stem damage to pons and lesions that compress lower thalamus and midbrain
- rigid extension
- arms fully extended, forearms pronated, wrists/fingers flexed
- jaw clenched, neck extended, back may be arched
- feet plantar flexed
- may occur spontaneously, intermittently, or in response to stimuli
What is aphasia?
- disorder in producing/understanding speech
- causes: lesions in dominant cerebral hemisphere (L)
- Broca’s aphasia: (expressive) nonfluent, slow, articulation is impaired but meaningful (with nouns, transitive verbs, important adjs)
- Wernicke’s: (receptive) fluent, rapid, articulation good but sentences lack meaning; words malformed/invented
What is dysarthria?
- difficulty speaking due to abnormalities of oral and facial muscles that produce speech
- words may be nasal, slurred, or indistinct
- causes: motor lesions of the central or peripheral nervous system, parkinsonism, cerebellar disease
What are paraphasias?
words are malformed, wrong, or invented
How do you test for aphasia?
- word comprehension: one-staged and two-staged commands
- repetition: repeat phrase of one-syllable words
- naming
- reading comprehension
- writing
What is circumstantiality?
- speech characterized by indirection and delay in reaching the point due to unnecessary detail
- components have meaningful connection
- pts with obsessions
What is derailment?
- shifting from subject to others that are unrelated/related only obliquely without realizing subjects have no connection
- schizophrenia, manic episodes, psychosis
What is a flight of ideas?
- continuous flow of accelerated speech
- changing abruptly from topic to topic
- plays on words, distracting stimuli, no progress to sensible conversation
- manic episodes
What are neologisms?
- invented/distorted words or words with new/highly idiosyncratic meanings
- schizophrenia, psychotic disorders, aphasia
What is blocking?
- interruption of speech midsentence/before completion of an idea
- losing a thought
- profound in schizophrenia
What is confabulation?
- fabrication of facts/events in response to questions in order to fill in gaps in impaired memory
- Korsakoff’s syndrome from alcoholism
What is perseveration?
- repetition of words/ideas
- schizophrenia/psychosis or traumatic injuries
What is echolalia?
- repeating words/phrases of someone else
- manic episodes and schizophrenia
What is clanging?
- choosing word based on sound rather than meaning
- usually rhyming/punning
- schizophrenia and manic episodes
How can you assess Thought Content?
- assess during interview
- follow leads suggested by patient instead of asking stereotyped list of questions
- abnormalities include: compulsions, obsessions, phobias, anxieties, feelings of unreality, feelings of depersonalization, delusion (of persecution, grandeur, jealousy, reference, being controlled, somatic, systematized)
How can you assess Mental Function?
- orientation (name, date, place)
- attention
- digit spans (serial 7s or spell world backwards)
- remote memory
- recent memory
- new learning ability (repeat 3 words)
- higher cognitive functions including vocabulary, calculating ability, abstract thinking (proverb), and constructional ability (draw a clock)
How can you assess Judgment?
- ability to evaluate situation and form appropriate response
- assess by asking patient to propose solution to a current problem (how will you get to your follow-up appointment) and/or ask to propose solution to a hypothetical problem
How do you test the Olfactory Nerve (CN I)?
- test each nostril with a familiar, non-irritating odor
How do you test the Optic Nerve (CN II)?
- test visual acuity (confrontation)
How do you test the Optic Nerve (CN II) and Oculomotor Nerve (CN III)?
- inspect size and shape of pupils
- test pupillary reactions to light
- check near response
How do you test the Oculomotor Nerve (CN III), the Trochlear Nerve (CN IV), and the Abducens Nerve (VI)?
- test EOM in the six cardinal directions of gaze
- look for nystagmus, diplopia, and ptosis
How do you test the Trigeminal Nerve (CN V)?
- motor: palpate temporal and masseter muscles (ask patient to clench their teeth, ask pt to move jaw side to side)
- sensory: test for pain sensation and light touch in each of the 3 areas (ophthalmic, maxillary, and mandibular); corneal reflex
How do you test the Facial Nerve (CN VII)?
- motor limb of corneal reflex
- ask patient to raise both eyebrows,frown, close eyes tightly, smile, show both upper and lower teeth, puff out cheeks
How do you assess motor strength of the elbow?
- flexion (C5,6 - biceps)
- extensions (C6-8 - triceps)
How do you assess motor strength of the wrist?
- extension (C6-8, radial nerve)
How do you assess motor strength of the hand?
- test grip of hand (C7-8, T1)
How do you assess motor strength of the hip?
- adduction (L2-4, iliopsoas)
- abduction (L4-5, S1, gluteus medius and minimus)
- extension (S1 - gluteus maximus)
How do you assess motor strength of knees?
- flexion (L4-5, S1-2, hamstrings)
How do you assess motor strength of the foots?
- dorsiflexion (L4-5, tibialis anterior)
- plantar flexion (S1-gastrocnemius, soleus)
How do you assess cerebellar function?
- observe patient’s performance in rapid alternating movements (finger tapping)
- point-to-point movements (finger to nose test, heel to chin test)
- gait and other related body movements (walk normally, heel to toe, on toes, on heels, hop in place, shallow knee bed, rise from sitting position)
- standing in specified ways (Romberg test, pronator drift)
How you assess sensory pathway integrity?
- test pain and temp (spinothalamic tracts), position and vibration (posterior/dorsal column), light touch (both), and discriminative sensations
- compare symmetric areas
- compare distal with proximal areas
- vary place of your testing
- if you detect sensory loss/hypersensitivity, map out its boundaries
What are the deep tendon reflexes?
- ankle (S1)
- knee (L2, 3, 4)
- brachioradialis/supinator (C5, 6)
- biceps (C5, 6)
- triceps (C6, 7)
What are the cutaneous stimulation reflexes?
- abdominal: upper (T8, 9, 10) and lower (T10, 11, 12)
- plantar responses (L5, S1)
- anal (S2, 3, 4)
How do you assess for discriminative sensations?
- stereognosis
- graphesthesia
- two point discrimination
- point localization
- extinction
How do you assess for stereognosis?
- place familiar object in the patient’s hands while eyes closed
- ask them to identify it
How do you assess for graphestheisa?
- use pen to draw a # on patient’s palm
- ask them to ID the number
- bilaterally
How do you assess for two point discrimination?
- use 2 ends of an open paper clip to finger pads in two places
- then touch 1 place at a time and ask patient if they feel 1 or 2 points each time
How do you assess point localization?
- touch point on patient’s skin; ask pt to open eyes and point to place touched
How do you assess extinction?
- stimulate corresponding areas on both sides of the body simultaneously
- ask where pts feels your touch
What are the levels for Grading Muscle Strength (MRC Scale)?
- 0: no muscular contraction detected
- 1: barely detectable flicker or trace of contraction
- 2: active movement of body part with gravity eliminated
- 3: active movement against gravity
- 4: active movement against gravity and some resistance
- 5: active movement against full resistance without evident fatigue; normal muscle strength
What dysfunction is seen in Lower Motor Neuron damage?
- IPSILATERAL weakness and paralysis to the limbs
- muscle tone and reflexes are decreased or absent
What dysfunction is seen in Upper Motor Neuron Damage?
- above crossover in medulla, impairment develops on CONTRALATERAL side
- below crossover, impairment is IPSILATERAL side
- affected limb becomes weak or paralyzed, muscle tone is increased and deep tendon reflexes are exaggerated
What is the Babinski response?
- when testing plantar response (L5, S1), the big toe dorsiflexes (CNS lesion in corticospinal tract)
What is Clonus?
- test when reflexes seem hyperactive
- dorsiflex ankle and look to see if it maintains this position or if there are rhythmic oscillations (CNS disease)
What is Kernig’s sign?
- flex pt’s leg at both hip and knee and straighten knee
- positive sign indicated by pain and increased resistance to extending the knee
What is the Brudzinski Sign?
- as you flex neck (pt is passive), hips and knees also move (in pain)
What is the Doll’s Eye Response?
- hold patient’s upper eyelids open, turn head quickly
- eyes should turn toward opposite side otherwise the patient does not have an intact brainstem (used to test comatose patients)
What is the Romberg Sign?
- pt stands with feet together and closes eyes
- positive sign: swaying (dorsal column disease, cerebellar ataxia)
What is Pronator Drift?
- stand with arms straight forward, palms up, eyes closed
- look for drifting of either forearm (corticospinal tract lesion)
What is the Straight Leg Raise?
- raise pt’s relaxed and straightened leg
- if there is a painful radiculopathy associated with muscle weakness and dermatomal sensory loss can indicate sciatic or herniated disc
What is aphonia?
- loss of voice that accompanies disease affecting larynx or its nerve supply
- causes: laryngitis, laryngeal tumors, unilateral vocal cord paralysis (CN X)
What are the types of seizure disorders (3)?
- partial seizures
- generalized seizures
- pseudoseizures
What are the clinical manifestations of Partial Seizures?
- jacksonian or other motor: tonic than clonic movements that may spread
- ANS symptoms (nausea, pallor, flushing, lightheadedness)
- sensory/psychiatric phenomena: numbness, tingling, auditory/olfactory hallucinations, anxiety or fear
What is the postictal state of Partial Seizures?
normal consciousness in all
What are the clinical manifestations of Generalized Seizures?
- tonic-clonic (grand mal): loses consciousness suddenly, body stiffens, breathing stop, cyanosis, clonic phase follows, breathing resumes with excessive salivation
- absence: sudden brief lapse of consciousness with momentary blinking, staring, movements of lips/hands, no falling
- myoclonic: sudden, brief, rapid jerks of trunk or limbs
- myoclonic atonic: sudden loss of consciousness with falling but no movements, injury may occur
What is the postictal state of Generalized Seizures?
- tonic-clonic: confusion, drowsiness, fatigue, headache, muscular aching, sometimes temporary persistance of bilateral neurologic deficits (hyperactive reflexes, Babinski responses, amnesia for seizure)
- absense: no aura recalled
- myoclonic: variable
- myoclonic atonic: prompt return to normal or brief period of confusion
What are Pseudoseizures?
- clinical manifestations: movements may have personally symbolic significance, do not follow neuroanatomic pattern, injury uncommon
- postictal state: variable
What are the involuntary movements that we need to know? (6)
- tremors
- oral-facial dyskinesias
- tics
- athetosis
- dystonia
- chorea
What are the types of tremors? (3)
- resting: slow, fine, pill-rolling (Parkinson’s)
- postural: while maintaining a posture (hyperthyroidism, anxiety, fatigue, or can be benign)
- intention: absent at rest, appear with movement (cerebellar disorders, MS)
What are oral-facial dyskinesias?
- rhythmic, repetitive, bizarre movements of face, mouth, jaw, and tongue
- grimacing, pursing of lips, protrusion of tongue, opening and closing of mouth, deviation of jaw
- causes: long term psychotropic drugs, standing psychoses, elderly and edentulous persons
What are Tics?
- brief, repetitive, stereotyped, coordinated movements at irregular intervals
- causes: Tourette’s, drugs (phenothiazines and amphetamines)
What is Athetosis?
- slower, more twisting and writhing than choreiform movements with larger amplitude
- usually of face and distal extremities
- causes: cerebral palsy
What is Dystonia?
- similar to athetoid movements but often involve larger portions of body (including trunk)
- causes: drugs (phenothiazines), primary torsion dystonia
What is Chorea?
- brief, rapid, jerky, irregular, unpredictable movements that occur at rest or interrupt normal coordinated movements
- seldom repeat themselves
- causes: Sydenham’s chorea, Huntington’s disease