Neurology Flashcards
Definition of vertigo
sense of motion (usually spinning) when none exists
Definition of disequilibrium
feeling off balance or wobbly when standing or walking
Definition of pre syncope
feeling of about to pass out (faint, lose consciousness) or blacking out
Definition of lightheadedness
vague symptoms with possible feeling of being disconnected from environment
Causes of vertigo
(in order from most common to less common):
benign paroxysmal positional vertigo (BPPV)
Meniere’s disease
vestibular neuritis
labyrinthitis
central: CNS lesion (stroke, tumor), migraine, seizure
Causes of dysequilibrium
Stroke TIA Parkinson’s disease diabetic neuropathy muscle weakness affecting balance and gait poor vision
Causes of presyncope
Orthostatic hypotension
cardiac: arrhythmias, myocardial infarction, carotid artery stenosis
Causes of lightheadedness
psychiatric disorders including depression, anxiety, hyperventilation syndrome
Causes of dizziness due to medications
Cardiac medications CNS and psychiatric medications Muscle relaxants Sedatives Urologic medications
What is the Romberg test
Romberg’s test for proprioception and vestibular system
swaying towards one side indicative of vestibular dysfunction on ipsilateral side
What type of gait is associated with cerebellar cause of dizziness
ataxic gait (slow, wide based, irregular)
What is the purpose of the HINTS exam?
HINTS exam = Head Impulse, Nystagmus and Test of Skew
to rule out central cause (stroke, tumor, multiple sclerosis) for acute vertigo
How to conduct head impulse test in HINTS exam
1) Head Impulse Test
patient fix eyes on examiner’s nose while examiner move patient head in horizontal plane to left and right
central cause = intact reflex = patient eyes stay fixed on nose
peripheral cause = abnormal reflex = patient eyes do not stay fixed on nose with nystagmus to the side of which the eyes move
How to conduct nystagmus test in HINTS exam
2) Nystagmus
evaluation for nystagmus during eye movement exam during patient’s ocular pursuit of physician’s finger as it moves slowly left, right, up and down
nystagmus is involuntary movement of eyes in horizontal, vertical or rotatory plane
nystagmus consist of 2 phases: slow phase (smooth pursuit) and fast phase (saccade)
nystagmus is conventionally described by the direction of the fast phase e.g. nystagmus to the right = fast phase toward right and slow phase toward left
central cause = nystagmus that change direction when patient looks at different directions
peripheral cause = nystagmus always in same direction
How to conduct test of skew in HINTS exam
3) Test of Skew
patient focus on examiner’s nose
examiner covers one eye, then quickly uncover the eye
central cause = positive test of skew = patient’s covered and then uncovered eye need to re-align
peripheral cause = negative test of skew = patient’s eyes do not need to re-align with cover and uncover test
Interpretation of central vs peripheral cause for HINTS exam
central cause = normal head impulse, nystagmus changing directions and positive test of skew
if acute vertigo with central cause on HINTS test, then urgent CT or MRI to rule out stroke
peripheral test = abnormal head impulse, uni-direction nystagmus, negative test of skew
Hyperventilation test
if hyperventilation syndrome suspected (anxiety), then have patient rapidly take 20 deep inhalations and exhalations to reproduce symptoms
Dix Hallpike maneuver
positive Dix-Hallpike maneuver = reproduction of nystagmus and dizziness when patient’s head descended
Negative Dix Hallpike does not rule out BPPV
Diagnostic approach to dizziness
1) rule out focal CNS lesion (stroke, tumor)
if neurological deficit or HINTS exam suggesting CNS lesion, then urgent CT or MRI head
rule out medication, caffeine, nicotine, alcohol
2) for vertigo (usually in primary care setting) with neurological symptoms already ruled out classify on history vertigo vs disequilibrium vs pre syncope vs lightheadedness
a) if dizziness suggests vertigo
- migraine symptoms (aura, headache, photophobia, phono phobia) suggest migraine
- if associated with hearing loss, determine if episodic or persistent (episodic vertigo with hearing loss suggest Meniere’s disease, persistent vertigo with hearing loss suggest labyrinthitis)
- if no hearing loss, determine if episodic or persistent vertigo (episodic vertigo with no hearing loss and positive Dix-Hallpike suggest BPPV, persistent vertigo without hearing loss suggest vestibular neuritis)
b) if dizziness suggests disequilibrium
- decreased sensation in foot and legs suggest peripheral neuropathy
- TRAP (tremor, rigidity, akinesia, postural instability) suggest Parkinson’s disease
- poor vision suggest poor vision as cause of disequilibirum
- Romberg test
- ataxic gait and abnormal cerebellar testing suggest cerebellar cause of disequilibirum
c) if dizziness suggests pre syncope
- history of cardiac disease (arrhythmia, myocardial infarction, aortic stenosis) or abnormal cardiac examination suggest cardiac disease as cause for pre syncope - consider cardiac testing including resting ECG, echocardiogram, cardiac stress test
- postural changes in blood pressure or pulse suggest orthostatic hypotension
d) if dizziness suggests lightheadedness history of psychiatric symptoms / diagnoses (anxiety or depression) or positive hyperventilation provocation test suggest psychiatric cause
Vertigo management
- Address underlying cause
- Anticholinergic Meclizine to increase motion tolerance
- Antihistamine Dimenhydrinate to prevent motion sickness and decrease severity of dizziness
- Lorazepam to suppress vestibular system
Orthostatic hypotension management
- Lifestyle modification - increase fluid intake, sleep with bed elevated, increase salt intake, regular exercise
- Alpha 1 agonist Midodrine (Proamatine) to increase blood pressure
- Mineralocorticoid Fudrocortisone to increase water retention
- Pseudoephedrine to increase blood pressure
- Paroxetine to increase blood pressure
- Desmopressin to increase water retention
Anxiety related hyperventilation dizziness management
- Breathing control exercises, breathing into paper bag
- Beta blocker
- Anti-anxiety agents (SSRI, benzos)
BPPV pathophysiology
calcium debris (cupulolithiasis) in posterior semicircular canals
What is considered a positive Dix Hallpike
Reproduction of symptoms
reversibility = nystagmus changes direction with different position of Dix-Hallpike test
latency = nystagmus occur only after a few moments after patient is in supine position during Dix-Hallpike test
How do you conduct an Epley maneuver
1) patient sit on examination table, with eyes open and head turned 45 degrees to affected side A
2) examiner support head as patient quickly goes to supine position with head extended
3) physician turns patient head to other side B 90 degrees, remaining for 30 seconds
4) physician turns patient head to other side B 90 more degrees while patient rotate body 90 degrees in same direction, remaining for 30 seconds
maneuver of series of positions to relocate particle back into utricle
80% success with 1 treatment; 100% success with multiple treatment
patient can learn this as vestibular rehabilitation exercise
Meniere’s disease pathophysiology
Idiopathic, but proposed mechanism is excessive endolymph fluid in inner ear (endolympahtic hydrous), which cause swelling of endolymphatic sac that eventually burst and flow into other areas
Meniere’s disease clinical presentation
- episodic debilitating rotational vertigo, which can be severe, incapacitating and unpredictable lasting minutes to hours to days
- vertigo can be accompanied by nausea and vomiting
- fluctuating unilateral or bilateral low frequency sensorineural hearing loss
- unilateral or bilateral tinnitus
- sensation of fullness or pressure in ear
- signs include ataxia and nystagmus during acute event
Meniere’s disease treatment
1) lifestyle modification
smoking cessation
salt restriction (<2g sodium per day)
2) diuretics
Hydrochlorothiazide / Triamterene (Dyazide)
3) medication for symptomatic relief
antihistamine Behahistine
if severe vertigo refractory to medication, then surgical labyrinthectomy (removal of affected inner ear)
Vestibular neuritis pathophysiology
Idiopathic, but proposed mechanism is infection of vestibular nerve ganglion causing inflammation
Vestibular neuritis clinical presentation
onset may be preceded by upper respiratory tract
infection sudden onset debilitating vertigo lasting days
can have n/v
ataxia, nystagmus
Vestibular neuritis treatment
vestibular neuritis usually self limited and improves over 3-6 weeks
patients should be reassured and recommended to rest
1) systemic steroid Methylprednisolone PO (Depo-Medrol)
2) medication for symptomatic relief
antihistamine Gravol
serotonin antagonist Ondansetron
Meniere’s disease investigations
audiometry: low frequency sensorineural hearing loss
ENG: decreased vestibular activity
Vestibular neuritis investigations
audiometry: no hearing changes
ENG: reduced vestibular activity
What is tested by the Romberg test
With the eyes open, three sensory systems provide input to the cerebellum to maintain truncal stability - vision, proprioception, and vestibular sense.
If there is a mild lesion in the vestibular or proprioception systems, the patient is usually able to compensate with the eyes open.
When the patient closes their eyes, however, visual input is removed and instability can be brought out.
If there is a more severe proprioceptive or vestibular lesion, or if there is a midline cerebellar lesion causing truncal instability, the patient will be unable to maintain this position even with their eyes open.
Note that instability can also be seen with lesions in other parts of the nervous system such as the upper or lower motor neurons or the basal ganglia, so these should be tested for separately in other parts of the exam.
Headache red flags, corresponding differential diagnosis and investigations
1) onset age >50 years
differential diagnoses include temporal arteritis, brain
tumor work up includes head imaging (CT or MRI), ESR
2) sudden onset headache (reaching maximal intensity in seconds or minutes), first headache or worst headache
differential diagnoses include intracranial bleed especially SAH or brain tumor
work up includes head imaging (CT or MRI) and follow up lumbar puncture if head imaging is negative
3) headache with change of increased frequency or severity (i.e. change form previous pattern)
differential diagnoses includes brain tumor, subdural hematoma, medication induced headache
insidious progressive headache over course of days to months or headache worse at night or upon awakening suggests brain tumor
work up includes drug screen, head imaging (CT or MRI)
4) new onset headache in high risk population (immunocompromised)
differential diagnoses include meningitis, brain abscess and brain metastases
work up includes head imaging (CT or MRI) and lumbar puncture
5) headache with systemic illness (fever, meningismus, rash)
differential diagnoses include meningitis, encephalitis, systemic infection, collagen vascular disease, temporal arteritis
work up includes head imaging (CT or MRI), lumbar puncture, ESR and serology
6) focal neurological deficits, confusion, loss of consciousness, change in personality
differential diagnoses include brain tumor, stroke, vascular malformation, collagen vascular disease, brain abscess, venous sinus thrombosis, encephalitis
work up includes head imaging (CT or MRI), connective tissue work-up
7) papilledema
differential diagnoses includes mass lesion, meningitis, idiopathic intracranial hypertension
work up includes head imaging (CT or MRI), lumbar puncture
8) head trauma
differential diagnoses include intracranial hemorrhage and hematoma (epidural hematoma, sub-dural hemorrhage)
work up includes head imaging (CT or MRI), X-ray of skull and C-spine
9) headache during pregnancy or post partum period headache
suggest cortical vein or venous sinus thrombosis, carotid dissection or pituitary apoplexy
Pharmacologic symptomatic relief of secondary headache
Acetaminophen or NSAID
may consider prescribing opioids for severe headache
if nausea, then anti-emetics or sedatives such as diphenhydramine, prochlorperazine, chlorpromazine, droperidol, metoclopramide
Migraine stages
- Prodrome
- hours to days before headache
- non specific symptoms due to hypothalamus activity ( yawning, mood, thirst, hunger, etc) - Aura
- visual, sensory, speech positive or negative symptoms
- Occurs gradually over 5-20 minutes and lasts <1 hour - Headache
- unilateral throbbing and pounding headache usually localized to frontotemporal region aggravated with exertion 4 hours to 3 days in duration - Post drome
- hours to days after headache - fatigue, soreness, confusion etc
Symptoms associated with migraine headache
N/V
Photophobia
Phonophobia
Migraine management
1) lifestyle modification
2) medication abortive therapy to relieve symptoms during current headache
abortive therapy options include triptans, ergots, conventional analgesics, narcotic analgesics
prophylactic therapy taken everyday to prevent headaches
prophylactic therapy options include tricyclic antidepressants (amitriptyline), anti-epileptics (divalproex, topiramate), beta blockers (propranolol) and serotoninergic compounds (methysergide, pizotylline)
What is the goal of abortive therapy for migraines?
Full relief of pain within 2 hours of initiation
Algorithm step up for abortive therapy in migraines?
Mild migraine: acetaminophen and NSAID
Moderate: acetaminophen, NSAID, triptans
Severe: triptans, opioids, corticosteroids (and possible ergotamine)
If n/v use anti-emetics (parenterally)
Triptans MOA
Serotonin agonist that activates 5HT1B/1D receptors on pre synaptic 1st order C fiber neuron of the trigeminal nerve endings.
This inhibits release of NTs by presynaptic neuron to inhibit neuro transmission of pain
5HT1B1D agonism also causes vasoconstriction of cranial vessels, which may help alleviate vasodilation related headache
Triptan contraindications
Ischemic cardiac disease
CVD
PVD
Uncontrolled severe HTN
Pregnancy
Ergotamine MOA
mixed partial agonist at 5HT1B/1D and alpha-adrenoceptors
Ergotamine side effects
Prolonged vasoconstriction, whcih can result in distal necrosis of limbs
Uterine spasm
Ergotamine contraindications
same as triptans
Indications for prophylactic migraine therapy
2-3 migraine attacks per month
migraine attack lasting >2 days
inadequate abortive therapy relief
migraine attack after prolonged aura
migraine severely disrupting quality of life
First line prophylactic migraine therapy medications with established efficacy
Propranolol, metoprolol
Amitriptyline
Valproic acid, topiramate
Tension headache clinical presentation
Band like or vice like pressure headache, usually bl, mild to moderate
Tension ha management
Lifestyle - stress
Analgesic (NSAID, acetaminophen) for episodic tension ha
Tricyclic antidepressant amitriptyline is 1st line for chronic tension ha
NaSSA (Mirtazapine) or SNRI (Venlafaxine) is 2nd line for chronic tension ha
Cluster ha clinical presentation
Recurrent severe unilateral ha, typically behind eye
Pain usually stabbing, burning or squeezing
Usually at night, 1-3 times in a day, lasting 15 min to 3 hours
Accompanied by autonomic symptoms, restlessness, difficulty concentrating
Cluster ha management
Abortive therapy - oxygen and triptans
Prophylactic - lithium or CCB
Medication overuse headache management
Detox by discontinuing all analgesic and ha related medication
If patient has history of migraine, during detox, start prophylactic medication for migraine
Detox may require medical supervision
Cervicogenic ha diagnosis
Pain referred from source in neck
Evidence of lesion in neck
Evidence that pain can be attributed to neck through clinical signs or relief with anesthetic block of C1-C4
Pain resolves within 3 months after tx of neck lesion
Cervicogenic ha treatment
- Physical therapy
- Anesthetic blockade
- Radiofrequency neurotomy, glucocorticoid injections, surgery
Indications for surgery for cervicogenic ha
- C2 spinal nerve compression by structures
- OA of lateral C1-2 joint
- Upper cervical intervertebral disc pathology
