Neurological Assessment Flashcards
Which CN are direct extensions from the brain
CNs I & II are white matter tracts that emerge as direct extensions from the brain
CN I
Olfactory nerve = sense of smell
CN II
Optic nerve = Sight
CN III
Oculomotor nerve = all eye muscles, except for superior oblique & external rectus muscle
CN IV
Trochlear nerve = superior oblique muscle of the eye
CN V
Trigeminal nerve = sensory to the face, sinuses and teeth; chewing muscles
CN VI
Abducens nerve = external rectus muscle of the eye
CN VII
Facial nerve = muscles of facial expression
CN VIII
Vestibulocochlear nerve = balance and hearing
CN IX
Glossopharyngeal nerve = sensory to the posterior tongue, tonsils, & pharynx; pharyngeal muscles
CN X
Vagus nerve = sensory & muscular inner action to the heart, lungs, bronchi, & digestive system; sensory in the trachea, larynx, pharynx, and external ear
CN XI
Accessory nerve = sternocleidomastoid & trapezius muscles
CN XII
Hypoglossal nerve = muscles of the tongue
How many pairs of spinal nerves are there?
- 31 pairs of spinal n.
- 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, & 1 coccygeal
What do peripheral nerves contain?
Both sensory (afferent) and motor (efferent) fibers
How does the Corticospinal tract control motor pathways
- Mediates voluntary movement and integrates skilled, complicated, or delicate movements by stimulating selected muscular actions and inhibiting others
- “Brain to spinal cord”
- Fibers decussate = cross in the medulla = right side of the brain controls movement of the left side of the body
- Higher motor pathways depend on intact lower motor neurons to affect movement
How does the Basal Ganglia system control motor pathways?
- Maintains normal muscle tone and to control body movements, especially gross automatic movements (walking)
What happens when the Basal ganglia is damaged?
- Damage causes rigidity, bradykinesia, involuntary movements, and/or disturbances in posture and gait
How does the Cerebellar system control motor pathways?
- Receives both sensory and motor input
- Coordinates motor activity, maintains equilibrium, and helps to control posture
What happens when the Cerebellar system is damaged?
- Damage can impair coordination, gait, equilibrium, decrease muscle tone, nystagmus or dysarthria
What is Corticobulbar motor pathway? What nerves does it directly innervate?
- Conducts impulses from the brain to the cranial nerves
- only 50% of these fibers decussate
- Directly innervates the nuclei of:
- V, VII, IX, and XII
- Contributes to the motor function of X
What happens when the Upper motor neurons of the corticospinal tract are damaged?
- increased muscle tone and HYPERreflexia b/c the lower motor neurons are disinhibited
What happens when the Lower motor neurons of the corticospinal tract are damaged?
- Decreased muscle tone and HYPOreflexia; atrophy and fasciculations
Corticospinal tract damage
- The corticospinal tracts have inhibitory effect on lower motor neurons
= weakness can be caused by damage to upper or lower motor neurons - Skilled, complicated or delicate movements are lost (not gross movements)
- When motor systems are damaged above their crossover in the medulla, motor impairment develops on the contralateral side
- Damage below the crossover = motor impairment on the ipsilateral side of the body
Sensory impulses give rise to what 3 things?
- Conscious sensation
- Location of body position in space
- Help regulate internal autonomic functions
Where do sensory impulses travel to in the spinal cord?
Dorsal (posterior) root ganglia in the spinal cord
What are the 2 pathways from the spinal cord to the sensory cortex of the brain?
- Spinothalamic tract = smaller sensory neurons with UNmyelinated or thinly myelinated axons
- Posterior columns = larger neurons with HEAVILY myelinated axons
What is the pathway of the spinothalamic tract
- Peripheral SMALL-fiber neurons arising in free nerve endings in the skin register:
- Pain, temperature, & crude touch
- these fibers pass into the posterior horn & synapse with 2nd order neurons
- 2nd order neurons then cross to the opposite side & pass upward into the thalamus
What is the pathway of the posterior column system (Dorsal column)
- Peripheral large-fiber projections transmit the sensation of:
- Vibration, Proprioception, Kinesthesia, Pressure, & Fine touch from the skin & joint
- Central projections travel upward in the posterior columns to 2nd order sensory neurons in the medulla on the SAME side of the body
- 2nd order neurons cross to the opposite side at the medullary level & continue to the thalamus
At the level of the thalamus what is perceived?
- The general quality of sensation (pain, cold, pleasant, unpleasant), but not fine distinction
For full perception of sensory where are impulses sent?
- To the sensory cortex of the brain
- Here stimuli are localized & higher-order discriminations are made
What level is the T4 dermatome?
Nipple level
What level is the T10 dermatome?
Umbilicus level
What level is the cardiac accelerator fiber located at?
T2
What dermatome level covers the inguinal area?
L4-L5
If you are performing a saddle block what dermatome/nerves are you blocking?
Sacral n.
If you are repairing an inguinal hernia what level do you want to block?
T10 - at least 3-4 dermatomes higher than the incision site
True or False the spinal reflexes occur due to the muscle stretching over structures relaying sensation from the PNS only.
False.
- The muscle stretch reflexes are relayed over structures of both the CNS and PNS
List the components of the reflex arc: (5)
- Sensory nerve fibers
- Spinal cord synapse
- Motor nerve fibers
- Neuromuscular junction
- Muscle fibers
Spinal nerves involved in the tricep reflex?
Cervical 6 & 7
Spinal nerves involved in the Brachioradialis (supinator) reflex?
Cervical 5 & 6
Spinal nerves involved in the Biceps reflex?
Cervical 5 & 6
Spinal nerves involved in the knee reflex?
Lumbar 2, 3, & 4
Spinal nerves involved in the ankle reflex?
Sacral 1
What are two guiding questions when assessing neuro health history?
- What is the localization of the responsible lesion (or lesions) in the nervous system?
- What is the underlying pathophysiology that explains the patient’s symptoms and neurologic findings?
What are the most common or concerning symptoms in the neuro assessment?
- Headache
- Dizziness or lightheadedness
- Weakness (generalized, proximal, or distal)
- Numbness or abnormal or absent sensation
- Fainting and blacking out (near-syncope & syncope)
- Seizures
- Tremors or involuntary movements
Primary headaches
- No underlying cause:
- migraine, tension, cluster, trigeminal autonomic cephalgias & chronic daily headache
Secondary headaches
- Arise from underlying structural, systemic, or infectious causes
- Meningitis & Subarachnoid hemorrhage
Headache warning signs (10)
- Progressively frequent over a 3-mo period
- Sudden onset “sudden clap” or “the worst headache of my life”
- New onset after 50 yo.
- Aggravated/relieved by change in position
- Precipitated by Valsalva maneuver or exertion
- Associated symptoms of fever, night sweats, or weight loss
- Presence of cancer, HIV, or pregnancy
- Head Trauma
- Change in pattern from past headaches/ lack of similar headaches in the past
- Associated papilledema, neck stiffness, or focal neurologic deficits
How is a migraine headache different ?
- Often preceded by an aura
- 3 of the 5 “POUND” features present:
- Pulsatile or throbbing
- One-day duration or 4-72 hrs if untreated
- Unilateral
- Nausea or vomiting
- Disabling or intensity causing interruption of daily activity (photophobic)
An atypical presentation of the patient’s usual migraine may be suspicious for what?**
- Stroke, especially in women using hormonal contraceptives
- WHO advises women with migraines over age 35 with an aura to avoid use of estrogen-progestin contraceptives d/t the increase risk of CVA
Focal or asymmetric weakness
- Both central & peripheral causes
- Central: ischemic, thrombotic, or mass lesions
- Peripheral: nerve injury to the neuromuscular junction disorders to myopathies
Describe the weakness caused by a TIA/stroke
- Abrupt onset of motor & sensory deficits
Describe the weakness caused by Guillain Barre syndrome
- Rapid development of lower extremity weakness followed by upper extremity weakness
Describe the weakness caused by expanding tumors or amyotrophic lateral sclerosis
- Chronic, more gradual, progression of weakness
Global
Describe the weakness caused by Myasthenia Gravis
- Proximal weakness that gets worse with effort (fatigability), often with associated bulbar symptoms such as diplopia, ptosis, dysarthria, & dysphagia
- Think airway
Described the weakness caused by Diabetes
- Bilateral predominantly distal weakness, often with sensory loss
“peripheral neuropathy”
Describe the weakness caused by Myopathy
- Symmetric weakness of the proximal muscles
- alcohol, glucocorticoids, & inflammatory muscle disorders
Describe the weakness caused by Polyneuropathy
- Symmetric weakness of distal muscles (digits)
Numbness/ abnormal/ absent sensation associated with Diabetes:
- Small fiber neuropathy: patients report sharp, burning, or shooting foot pain
- Large fiber neuropathy: patients report numbness, tingling or no sensation
- Progresses in a “STOCKING- GLOVE” distribution
Name an example of numbness/ abnormal sensation from Local nerve compression
- i.e., hand numbness in distributions specific to the median, ulnar, or radial nerve
Name an example of nerve root compression
- i.e., dermatomal sensory loss from vertebral bone spurs or herniated discs
Name an example of numbness/ abnormal sensation from a central lesion
- i.e., stroke or multiple sclerosis can cause hemiaesthesia
Name an example of numbness/ abnormal sensation from multiple patchy areas of sensory loss in different limbs
- vasculitis & rheumatoid arthritis
What is the most common cause of a syncopal episode?**
Vasovagal syncope
- others include:
- postural tachycardia syndrome
- carotid sinus syncope
- orthostatic hypotension
- arrhythmias, especially ventricular tachycardia & bradyarrhythmias
True or False Epilepsy always involves loss of consciousness
False.
- Epilepsy does not always involve loss of consciousness
Seizures in adults usually present as?
- Partial seizures
Describe a Generalized seizure
- Tonic-clonic motor activity, bladder or bowel incontinence, & an altered level of consciousness after a seizure episode (postictal state)
List 7 acute causes of symptomatic seizures
- Head trauma
- Alcohol
- Cocaine
- Withdrawal from alcohol, benzodiazepines & barbiturates
- Metabolic insults: low or high glucose, or low calcium/sodium
- Acute stroke
- Meningitis or encephalitis
Describe a tremor
- A rhythmic oscillatory movement of a body part resulting from the contraction of opposing muscle groups
Tremors associated with Parkinson disease
- Unilateral resting tremor, rigidity, bradykinesia, and postural instability
Describe an essential tremor
- A high-frequency, bilateral, upper extremity tremor that occurs with both limb movement & sustained posture & subsides when the limb is relaxed
(head, voice, & leg tremor may also be present)
“tremor presents when trying to feed self”
Restless leg syndrome
- Distinct from tremors
- An unpleasant sensation in the legs, especially at night, that gets worse with rest & improves with movement of the symptomatic limb
What are 3 reversible causes of Restless leg syndrome?
- Pregnancy
- Renal disease
- Iron deficiency
What are the 5 components of the Neuro Exam?
- Mental status, speech, & language
- Cranial nerves (CNs)
- Motor system
- Sensory system
- Reflexes
What are the cranial nerves used to assess speech
- V, VII, IX, X, XII
articulation, voice quality
Describe the symptoms associated with CN I damage
- Loss of smell occurs in:
- Sinus conditions
- Head trauma
- Smoking
- Aging
- Use of cocaine
- Parkinson disease
Describe the symptoms associated with CN III & IV damage
- Abnormal pupillary constriction in CN III palsy, intracranial aneurysm & brainstem herniation
Describe the symptoms associated with CN III damage
- Ptosis in third nerve palsy
- Horner syndrome or Myasthenia gravis
Describe the symptoms associated with CN VII damage
- Bell palsy - affects both the upper and lower face (loss of taste, hyperacusis, +/- tearing)
- A central lesion affects mainly the lower face
Describe Horner Syndrome
- Results from paralysis of the ipsilateral sympathetic cervical chain (stellate ganglion) caused by:
- Surgery, drugs (mainly high concentrations of local anesthetics), local compression (hematoma or tumor), or inadequate perioperative positioning of the patient
What are the clinical symptoms of Horner Syndrome
- Ipsilateral ptosis
- Miosis
- Forehead anhidrosis
What are the 4 blocks that can cause Horner Syndrome
- Unusual side effect of epidural analgesia
- Stellate ganglion block
- Interscalene block of the brachial plexus (100%)
- Or other types of supraclavicular blocks
Spasticity
- Velocity-dependent increased tone (increases with more rapid movement)
- Worsens at extremes of range of motion (increase angle)
- Seen in central disease affecting the CORTICOSPINAL TRACT
Rigidity
- Increased tone that remains the same throughout ROM (not velocity dependent)
- Seen in central disorders affecting the basal ganglia (PARKINSON DISEASE)
What is the Romberg Test for?
A test of position sense
- Stand with feet together & eyes open & then both eyes closed for about 30 seconds
- Note the patient’s ability to maintain an upright posture (minimal sway is normal)
Describe a positive Romberg Test
- Patient stands well with eyes open; but loses balance when eyes are closed
Sensory ataxia
- Vision compensates for the sensory position loss, so patient has a + Romberg test
Cerebellar ataxia
- The patient has difficulty standing with feet together whether the eyes are open or closed = + Romberg Test
What are the 3 Meningeal Signs
- Nuchal Rigidity = flex the neck forward, chin to chest (normal = supple)( + sign = resistance & painful)
- Brudzinski sign = flex the neck & watch hips and knees (normal = relaxed position)(+ sign = flex neck = flex hips & knees)
- Kernig Sign = Flex the patients leg at both the hip and the knee, & then slowly extend the leg and straighten the knee (normal = no discomfort) (+ sign = pain & increased resistance)
What are the 2 types of coma classifications?
- Structural
2. Metabolic
Assessing the comatose patient: Pupillary light reflex assess what CN
- CN II & III
Assessing the comatose patient: Ocular position & movement assess what CN
- CN III, IV, & VI
Assessing the comatose patient: Oculocephalic reflex assess what CN
- CN III, IV, VI, & VIII
Assessing the comatose patient: Oculovestibular reflex w/ caloric stimulation assess what CN
- CN III, IV, VI, & VIII
Assessing the comatose patient: Corneal reflex assess what CN
- CN V & VII
- lesions present = absent blinking in both eyes
Assessing the comatose patient: Facial asymmetry, grimace in response to painful stimulus assess what CN
- CN VII
Assessing the comatose patient: Gag reflex assess what CN
- CN IX & X
What is one of the most important signs of distinguishing structural from metabolic causes of coma
- Pupillary reaction to light
- Light reaction often remains intact in metabolic coma
- Structural lesions (CVA, abscess) lead to asymmetrical pupils & loss of light reaction
In a structural hemispheric lesion, what would you anticipate the ocular position and movement to be?
- The eyes “look at the lesion” in the affected hemisphere
In a unilateral pontine lesion or in a seizure affecting one hemisphere, what would you anticipate the ocular position and movement to be?
- The eyes “look away” from the affected side
No response in posture on one side suggests ?
- Corticospinal tract lesion
What are the 5 subtypes of ischemic stroke
- Cardioembolic (e.g., from atrial fibrillation)
- Large vessel atheroembolic (e.g., from carotid artery stenosis)
- Small vessel disease (hypertension & diabetes)
- Other, including cervical artery dissection or a hypercoagulable state
- Cryptogenic = when no cause is found
What are the 4 subtypes of hemorrhagic stroke
- Intraparenchymal
- Subarachnoid (aneurysmal or non-aneurysmal)
- Subdural
- Epidural
What is most effective in preventing permanent neurologic injury
- Thrombolytic therapy, when administered within 4.5 hrs. of symptom onset
What are the 5 Stroke attack warning signs
- Sudden numbness or weakness of the face, arm, or leg
- Sudden confusion, trouble speaking or understanding
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, or loss of balance or coordination
- Sudden severe headache
Describe TIA
- Neurologic dysfunction that resolves within 24 hrs
- One of the strongest risk factors for stroke
Short-term stroke risk following a TIA is highest in:
- > 60yrs
- Diabetes
- Focal symptoms of weakness or impaired speech
- Symptoms lasting more than 10 minutes
List 11 modifiable stroke risk factors
- Hypertension
- Diabetes
- A-fib
- Smoking/tobacco
- Physical inactivity
- Dyslipidemia
- Weight
- Chronic kidney disease
- Diet & nutrition
- OSA
- Sickle cell disease
Respiratory pattern of Metabolic coma
- If regular = normal or hyperventilation
- If irregular = usually Cheyne- Stokes
Respiratory pattern of Structural coma
- Irregular, especially Cheyne-Stokes or ataxic breathing
- Also with selected stereotypical patterns like “apneustic” respiration (peak inspiratory arrest) or central hyperventilation
Pupillary size & reaction in Metabolic coma
Equal, reactive to light
- Pinpoint = opiates or cholinergics
- Fixed & dilated = anticholinergics or hypothermia
Pupillary size & reaction in Structural coma
Unequal or unreactive to light
- Midposition, fixed - suggests midbrain compression
- Dilated, fixed - suggests compression of CN III from herniation
Level of consciousness in Metabolic coma
- Changes after pupils change
Level of consciousness in Structural coma
- Changes before pupils change
Examples of causes of Metabolic coma
- Uremia
- Liver failure
- Hyper & Hypo glycemia
- Alcohol
- Drugs
- Hypothyroidism
- Anoxia
- Ischemia
- Meningitis
- Encephalitis
- Hyper & hypothermia