Chapter 18 - Nervous System Flashcards
Cerebrovascular disease is ___ leading cause of death in US
3rd
Mental status exam evaluates:
- Level of consciousness
- Speech
- Orientation
- Knowledge of current events
- Judgment
- Abstraction
- Vocab
- Emotional responses
- Memory
- Calculation ability
- Object recognition
- Praxis
Describe patients in a coma
- Completely unconscious
- Cannot be roused even by painful stimuli
How to assess level of consciousness
Awake? Alert? Responsive?
How to evaluate a patient’s speech
Recite a short phrase like “no ifs, ands, or buts”
Define dysarthria
Difficulty in articulation
Define dysphonia
Difficulty in phonation (resulting in alteration in volume and tone of voice)
Lesions of the ____ are responsible for dysarthria
Tongue and palate
Lesions of the ____ are responsible for dysphonia
Palate and vocal cords
Define dysphasia
Difficulty comprehending or speaking
What causes dysphasia?
Cerebral dysfunction
Define aphasia
Total loss of speech
How to evaluate orientation
Patient’s awareness of self in relation to person, place, time
An abnormality in recent memory may be caused by a lesion where?
Temporal lobe
The ability to calculate depends on the integrity of what?
Dominant cerebral hemisphere AND patient’s intelligence
Define agnosia
Failure to recognize a sensory stimulus despite normal primary sensation
Define visual agnosia
Patient has normal vision and fails to recognize an object
Define tactile agnosia
Inability to recognize an object by palpation (w/o a sensory defect)
A lesion located in the ___ can cause tactile agnosia
Non-dominant parietal lobe
Define autotopagnosia
Patient’s inability to recognize his or her own body part
Define praxis
Ability to perform a motor activity
Define apraxia
Inability to perform a voluntary movement (w/o deficits in motor strength, sensation, or coordination)
Define dyspraxia
Decreased ability to perform a motor activity
Define constructional apraxia
Patient is unable to construct or draw simple designs (e.g. face of a clock)
A lesion in the ____ causes dyspraxia
Deep frontal lobe
A lesion in the ___ causes constructional apraxia
Posterior parietal lobe
CN 1 name and function
Olfactory - Smell
CN 2 name and function
Optic - Vision
CN 3 name and function
Oculomotor - eye movements, pupillary constriction, accommodation
CN 4 name and function
Trochlear - eye movements
CN 5 name and function
Trigeminal - general sensation of face/scalp/teeth, chewing movements
CN 6 name and function
Abducens - eye movements
CN 7 name and function
Facial - expressions, taste, general sensation of palate/external ear, salivary gland secretion
CN 8 name and function
Vestibulocochlear - hearing and equilibrium
CN 9 name and function
Glossopharyngeal - taste, elevation of palate, parotid gland secretion, general sensation of pharynx and ear
CN 10 name and function
Vagus - taste, swallowing, phonation, parasympathetic innervation of heart and abdominal viscera, general sensation of pharynx, larynx, ear
CN 11 name and function
Spinal accessory - phonation, head/neck/shoulder movements
CN 12 name and function
Hypoglossal - tongue movements
When should CN 1 be tested?
Suspected frontal lobe disorder
Divisions of trigeminal nerve
Ophthalmic
Maxillary
Mandibular
Unilateral weakness of CN 5 (motor) causes what to happen when patient chews?
Jaw deviates TOWARD side of lesion
How do upper motor neuron lesions affect the face?
Contralateral weakness of lower face but SPARES forehead (e.g. stroke)
How do lower motor neuron lesions affect the face?
Total paralysis of ipsilateral face, does NOT spare forehead
e.g. Bells palsy
Fasciculations are indicative of a ___ lower motor neuron lesion
Hypoglossal
The motor system is evaluated for:
Muscle bulk, strength, tone
Proximal muscle weakness is related to:
Muscle disease
Distal muscle weakness is related to:
Neurologic disease
Define muscle tone
Slight residual tension in a voluntarily relaxed muscle
How is muscle tone assessed?
Resistance to passive movement
What clinical features do upper motor neuron lesions produce?
Hyperreflexia
Babinski’s sign
Clonus
Spasticity
What clinical features do lower motor neuron lesions produce?
Hyporeflexia
Fasciculations
Atrophy
Decreased tone
How can you make fasciculations more apparent?
Gently tap muscle with reflex hammer
Define cogwheeling
Ratchety jerkiness to motion
Hyperactive reflexes are characteristic of what type of disease?
Pyramidal tract
electrolyte abnormalities, hyperthyroid
Diminished reflexes are characteristic of what type of disease?
Anterior horn cell disorders and myopathies
What is a hung reflex?
- Decreased relaxation after a DTR
- Occurs with hypothyroidism pts
Describe reinforcement with DTRs
- When someone has decreased DTRs, try reinforcement
- Isometric contraction of other muscles (clenching teeth, push down on bed with thighs)
What is Jendrassik’s maneuver?
- A form of reinforcement to try to elicit LE DTRs
- Patient locks fingers and tries to pull them apart
What DTRs are routinely tested?
Biceps Triceps Brachioradialis Patellar Achilles
What are the superficial reflexes?
- Abdominal (umbilicus moves toward stimulus)
- Cremasteric (men only, ipsilateral testicle raises)
The superficial abdominal reflex is frequently NOT seen in which patients?
Obese
What is the clinical significance of superficial reflexes?
LITTLE significance
What is Chaddock’s sign?
- Abnormal reflex a/w pyramidal disease
- Lateral aspect of foot is stroked and big toe dorsiflexes
What is Oppenheim’s sign?
- Abnormal reflex a/w pyramidal disease
- Downward pressure along the shin causes big toe to dorsiflex
What is Hoffmann’s sign?
- Abnormal reflex a/w pyramidal disease
- Flick fingernail of middle finger
- Positive response is adduction and flexion of thumb (the ok symbol)
Sensory exam consists of:
- Light touch
- Pain sensation
- Vibration sense
- Proprioception
- Tactile localization
- Discriminative sensations (2 point, stereognosis, graphesthesia)
Vibration sense is tested using what?
128-Hz tuning fork
How is proprioception tested?
Moving distal phalanx subtly (hold the sides of the digit)
Stereognosis is the integrative function of which lobes?
Parietal and occipital
How is cerebellar function tested?
FNF (finger nose finger) HKS (heel knee shin) Rapid alternating movement Romberg Gait
Define past pointing
Patients with cerebellar disease persistently overshoot the target in FNF testing
Define diadochokinesia
Ability to perform rapid alternating movements
Pronator drift is seen in patients with:
Mild hemiparesis
What is the Romberg test examining?
Posterior columns (rather than actual cerebellar function)
A patient with ____ tends to drag or circumduct a weak and spastic leg
Hemiplegia
A patient with ____ tends to shuffle with short, hurried steps
Parkinson’s
A patient with ____ walks with a wide based gait
Cerebellar ataxia
A patient with ____ has a slapping gait resulting from weakness of the ankle dorsiflexors
Footdrop
A patient with ____ has a high stepping gait in which the feet are slapped down firmly
Sensory ataxia
Decorticate posture - which abnormalities/lesions?
Cerebral hemispheric dysfunction OR destructive lesion of pyramidal tracts
Decerebrate posture - which abnormalities/lesions?
Midbrain or pons lesion
What does decorticate posture look like?
Arms adducted
Elbows/wrists/fingers flexed
Legs internally rotated
Feet plantarflexed
What does decerebrate posture look like?
Arms adducted
Elbows extended, forearms pronated
Wrists/fingers flexed
Feet plantarflexed
Central neurogenic hyperventilation is see in lesions of:
Midbrain or pons
Describe Cheyne-Stokes breathing
Rapid breathing separated by apnea episodes
A/w brainstem compression or bilateral cerebral dysfunction
Brainstem lesion and doll’s eyes reflex
Doll’s eyes reflex is ABSENT with a brainstem lesion
Doll’s eye reflex
- Turning a comatose pt’s head rapidly to one side while eyelids are held open
- Eyes SHOULD move conjugately to the other side
Why can doll’s eyes reflex only be elicited in a comatose patient?
Alert individuals will fixate on an object and override the reflex
What is caloric stimulation and what is it used for?
- Head flexed at 30 degrees, syringe of ice water is squeezed into one of the external auditory canals
- NORMAL response is nystagmus away from irrigation (warm water would cause nystagmus toward irrigation)
- Used to enhance doll’s eyes reflex or to test movements in a person with fractured cervical spine
How to remember caloric stimulation?
COWS - Cold Opposite, Warm Same
- Cold water causes nystagmus to other side of irrigation
- Warm water causes nystagmus to same side of irrigation
Extrapyramidal system is composed of:
Basal ganglia
Nuclei of midbrain and reticular formation
Cerebellum
