Dizziness and Syncope by sammyc2007

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									Dizziness and Syncope

  Naushira Pandya M.D., CMD
  Associate Professor and Chair
  Department of Geriatrics
  NSU COM
Definition
  Dizziness is a subjective sensation of postural
   instability or of illusory motion.
  Nonspecific term; includes
        vertigo
        disequilibrium
         lightheadedness
        spinning
        giddiness, faintness
        floating, feeling woozy
        many other sensations
Prevalence and Morbidity

    One of the most common presenting complaints in
     primary care practice for persons aged 65 years and
     older
    Prevalence ranges from 4% to 30%
    Dizziness increases with age (women are 30% more
     likely than men to report dizziness)
    Chronic dizziness has been associated with an
     increased risk of falls, syncope, functional disability,
    Strongly associated with fear of falling and reduced
     confidence in performing daily activities.
    Associated with worsening of depressive symptoms,
     self-rated health, and participation in social activities
Types of Dizziness
    Vertigo
       spinning or rotational sensation, either of the
        patient with respect to the environment or vice
        versa
    Presyncope
       feeling of lightheadedness or impending faintness
    Disequilibrium
       feeling of imbalance or unsteadiness usually not
        associated with any abnormal head sensations
    Other
       a vague feeling other than vertigo, presyncope, or
        disequilibrium.
       "floating," "wooziness," "spaciness," "whirling,"
Mechanisms of Equilibrium
    Complex integration of sensory information
     from the visual, auditory, vestibular, and
     proprioceptive systems by the cerebral cortex
     and cerebellum; use of this information for the
     appropriate motor response.

    Visual system helps in maintaining balance by
     providing signals from the retina to the
     occipital cortex; vestibulo-ocular reflex (VOR)
     controls the position of the eyes, enabling
     maintenance of a stable visual image during
     head movement.
The vestibulo-ocular reflex (VOR)

If you move your head to the
left, you will excite the left
horizontal canal, inhibiting
the right. To keep your eyes
fixed on a stationary point,
you need to fire the right
lateral rectus and the left
medial rectus, to move the
eyes to the right.
The semicircular canals
respond to changes in angular
acceleration, and the utricle
and saccule respond to linear
acceleration.
Mechanisms of Equilibrium…
  Hearing assists in stability by detecting and
   interpreting auditory stimuli; enables one to
   localize and be oriented in space
  Hearing is particularly helpful when other
   sensory modalities are impaired
  Although age-related visual,auditory,vestibular
   and propioceptive changes do not likely cause
   clinical disease, they may predispose older
   persons to the occurrence of dizziness (more
   vulnerable to impairments and disease
Causes of Chronic Dizziness
  Results from either discrete or combined
   effects of disorders or impairments in the
   multiple systems
  Discrete causes of chronic dizziness can be
   divided into
        central nervous system disorders
        vestibular disorders
        psychogenic causes
        systemic causes
        medications
        miscellaneous
Central nervous system disorders

Causes                History               Exam             Investigation        Treatment

Brainstem             Dizziness slurred     Detailed         CT or MRI scan;      Low-dose aspirin
(vertebrobasilar)     speech; visual        neurologic       MRI preferred        or clopidigel or
and/or cerebellar     changes; one-         examination                           DPA/ASA
infarcts/hemorrhage   sided weakness
s                     and/or gait ataxia;
                      truncal ataxia


Cerebellopontine      Vertigo or            Detailed         Audiometry;          Surgical excision
angle tumor:          dysequilibrium;       neurologic       asymmetric hearing
acoustic neuroma,     unilateral hearing    examination      loss;MRI
schwanomma            loss; tinnitus


                      Dysequilibrium;       muscular         Diagnosis made by    Antiparkinson
 Parkinson's          imbalance; slow       rigidity;        history and          treatment
disease               motor activities;     tremorbradykin   examination
                      slow walking          esia;
                                            orthostatic
                                            hypotension
       Vestibulocochlear system

Causes       History                        Exam                   Investigation           Treatment


Benign       Sudden intense vertigo -       Vertigo; nystagmus     None                    Epley maneuver
paroxysmal   days to months                 confirmed by Dix-                              Vestibular rehabilitation
positional                                  Hallpike maneuver;                             short course of
vertigo                                     absence of other                               vestibular
                                            signs                                          suppressants




Meniere's    Episodic vertigo; few          If unilateral, then    Audiogram-              Salt restriction and
disease      hours; tinnitus; fluctuating   VOR will be abnormal   sensorineural           diuretics Vestibular
             hearing loss; sensation of                            hearing loss (low       suppressants surgical
             fullness in ears                                      more than high          interventions,,
                                                                   frequencies)            gentamicin perfusion
                                                                    MRI to rule out
                                                                   retrocochlear lesions
Peripheral nerves
 Causes          History            Exam           Investigation      Treatment


 Diabetes;       Disequilibrium;    Decreased      Serum glucose;     Treatment of
 vitamin B12     worse in dark or   vibration or   B12 levels;        underlying
 deficiency;     on uneven          position       thyroid function   disease;
 hypothyroidis   surfaces           sense;         test; VDRL          good lighting;
 m; syphilis;                       steppage                          walking aid and
 idiopathic                         gait                              footwear;
                                                                       gait and
                                                                      balance
                                                                      training
                                                                      exercises
Cervical spine
 Causes            History        Exam              Investigation Treatment



 Degenerative      Neck pain,     Decreased         Cervical spine   Treatment of
 or                usually        neck range of     series           underlying
 inflammatory      episodic       motion;                            disease;
 arthritis,        dizziness      decreased                          cervical or
 spondylosis,      secondary to   vibratory or                       balance
 whiplash injury   change in      joint position                     exercises;
                   position of    sense;                             cervical collar;
                   the neck,      radiculopathy                      consider
                   history of     myelopathy or                      surgery
                   trauma or      vertebrobasilar
                   arthritis      ischemia
Vision
Causes         History         Exam           Investigation     Treatment



Presbyopia,    Difficulty in   Abnormal       Vision testing;   Good lighting
cataract;      vision; use     near/distant   referral to       without glare;
glaucoma;      of bifocals     acuity         ophthalmologist   refraction;
macular        or trifocals                                     consider
degeneration                                                    avoiding
                                                                bifocals or
                                                                trifocals;
                                                                drugs for
                                                                glaucoma;
                                                                surgery
Hearing
 Causes         History         Exam            Investigati    Treatment
                                                on


 Cerumen;       Difficulty in   Otoscopy:       Audioscopic    Cerumen
 presbycusis;   hearing in      cerumen;        examination;   removal; ear
 otosclerosis   social          abnormal        audiometry     wax drops;
                situations;     findings with                  hearing aid;
                unilateral or   whisper test,                  surgery (for
                bilateral       Rinne's test,                  otosclerosis);
                deafness        Weber's test                   hearing
                                                               rehabilitation;
                                                               listening
                                                               devices
Hypotension
Causes              History           Exam              Investigation    Treatment



Orthostatic         Near fainting:    Blood pressure    Investigations   Salt and water
volume/salt         worse when        and heart rate;   relevant to      repletion;
depletion; drugs;   getting up,       signs of          predisposing     adjustment or
vasovagal           walking,          predisposing      diseases         removal of
autonomic           complaints        diseases                           offending drugs;
dysfunction;        consistent with                                      treatment of
 diabetes;          predisposing                                         diseases; ankle
parkinsonism;       diseases;                                            pumps; elevate
 deconditioning     medication                                           head of bed;
                    history                                              stockings;
                                                                         reconditioning
                                                                         exercises; drug
                                                                         therapy,
                                                                         fludrocortisone,
                                                                         midodrine
Hypotension…
Causes         History           Exam           Investigation   Treatment



Postprandial   Same as           Postprandial   None            Frequent small
               orthostatic       blood                          meals; avoid
               hypotension       pressure and                   exertion after
               except onset is   heart rate                     meals; have
               within 1 h of     measurement                    caffeine with
               eating                                           meals; slow
                                                                rising; avoid
                                                                antihypertensive
                                                                drugs with or
                                                                near meal time
Systemic diseases
 Causes               History          Exam         Investigation    Treatment



 Cardiac/metabolic/   Symptoms of      Signs of     Relevant         Variable,
 respiratory: e.g.,   the underlying   the          investigations   depending on
 cardiac              diseases         underlying                    the underlying
 arrhythmias,                          diseases                      disease
 valvular lesions,
 CAD,
 cardiomyopathy;
 heart failure;
 COPD; diabetes;
 thyroid disorders;
 renal disorders;
 anemia
Psychiatric disorders
Causes       History           Exam         Investigation   Treatment


Anxiety,     Usually           Positive                     Psychotherapy;
depression   continuous        results on                   antidepressant
             nonspecific       anxiety or                   therapy after
             dizziness;        depression                   considering risks
             fatigue; poor     screening                    and benefits
             appetite; sleep
             problems;
             somatic
             complaints;
             poor
             concentration
Medications
Causes              History             Exam                 Investigation   Treatment



Ototoxic:           Vestibulocochlear   Nystagmus,                           Eliminate,or
aminoglycosides,    symptoms            bedside vestibular                   reduce specific
diuretics, NSAIDS                       function test can                    offending med if
vestibular                              be abnormal,                         possible; reduce
suppressants                            abnormal caloric                     the drugs to
                                        test                                 lowest possible
                                                                             dose
Others:             H/o fatigue;        May have postural
antihypertensives   confusion;          hypotension
antianxiety,        dizziness often
anticholinergics,   vague, can be
antidepressants,    continuous,
anticonvulsants,    dizziness can be
antipsychotics      postural
Chronic Dizziness as a Geriatric
Syndrome
   Dizziness in older persons was considered a symptom
    of one or more discrete diseases.
   Recent studies, however, suggest the possibility of a
    multifactorial etiology
   Factors independently associated with chronic
    dizziness include:
         anxiety
         depressive symptoms
         decreased hearing
         postural hypotension
         impaired balance and gait
         use of five or more medications
         past history of myocardial infarction
Evaluation- History
  The potential workup is extensive and
   expensive
  Stepwise approach to the evaluation of chronic
   dizziness is recommended
  Clinical history
        Intermittent, brief- BPV
        Hearing loss, tinnitus- Miniere’s disease
        Provoking factors (position or meals)
        Cardiac, DM, renal, anxiety, depression,
        Medications (include OTCs)
Physical examination
    Orthostatic changes in BP and pulse
    Ear exam (cerumen, structural problems)
    Hearing (whisper test or audioscope)
    Vision (near and distant)
    Spontaneous nystagmus? Horizontal in peripheral
     vestibular lesions or rotatory, suppressed by visual fixation, but in central
     lesions is vertical and is not suppressed by visual fixation.

  Cranial nerves (speech, dysphagia..)
  Cerebellar exam
  Range of neck motion
Routine laboratory evaluation
    Hematocrit
    Glucose
    Blood urea nitrogen, electrolytes
    Thyroid function tests
    Vitamin B12 levels
         in all patients complaining of dizziness.
    ECG if cardiovascular etiology is suspected, an ECG
     (Holter monitoring and tilt table testing)
    Audiometry and evoked responses
    Vestibular Function tests
    Neuroimaging
Investigate complaints fully!
Syncope in the Elderly
  Defined as a sudden transient loss of
   consciousness associated with loss of postural
   tone from which the patient recovers
   spontaneously
  Large differential diagnosis, ranging from
   common benign problems to severe life-
   threatening disorders.
  Hence approach to this symptom frequently
   results in hospital admission and performance
   of many diagnostic tests
Pathophysiology
    Caused by sudden decrease in cerebral to reticular
     activating system and both hemispheres
     (consciousness)
    Elderly patients often have multiple comorbid
     conditions that interact with age-related physiologic
     derangement, leading to a reduction in cerebral blood
     flow
    Elderly patients with hypertension and atherosclerotic
     vascular disease have baseline decreased cerebral
     blood flow
    Additionally multiple medications may further reduce
     cerebral blood flow by altering vascular tone or volume
Age-Related Cardiovascular Changes

    As a result of decreased baroreceptor reflex sensitivity, elderly
     may not be able to maintain cerebral blood flow by increasing
     heart rate and vascular tone in the setting of hypotension.
    Elderly are more sensitive to the effects of vasodilators and other
     hypotensive drugs
    More likely to have exaggerated hypotension from volume loss,
     hemorrhage, and upright posture.
    Systolic HTN, prevalent in more than 30%of persons over age
     75,also leads to diminished baroreflex sensitivity
    HTN may also increase the threshold for cerebral autoregulation,
     which can lead to a decrease in cerebral blood flow with modest
     acute decreases in blood pressure to levels within the
     normotensive ranges
Decreased Ability to Maintain Extracellular
Volume

   With aging, kidneys develop impairment of sodium
    conservation when salt intake is restricted.
   Basal plasma levels of renin and aldosterone are also
    decreased.
   These changes may increase the susceptibility of the
    elderly to orthostatic hypotension and syncope.
   As a result, the effects of diuretics, salt restriction, and
    upright posture may be more pronounced in the
    elderly.
Syncope
Etiologies of syncope.

  Neurally mediated syndromes
  Orthostatic hypotension
  Neurologic diseases
  Decreased cardiac output
  Other heart disease
  Arrhythmias
Neurally mediated syndromes
    Vasovagal
    Situational
        Micturition
        Cough
        Swallow
        Defecation
  Carotid sinus syncope
  Neuralgias
  High altitude
  Psychiatric disorders
  Others (exercise, selected drugs)
Orthostatic hypotension
  PrimaryAutonomic failure with multiple system
   atrophy
  SecondaryGeneral
     medical disorders: diabetes; amyloid;
      alcoholism
     Autoimmune disease: Guillain-Barre syndrome
     Metabolic disease: vitamin B12 deficiency;
      porphyria;
  Central brain lesions: vascular lesion or tumors
   (craniopharyngioma; multiple sclerosis;
   Wernicke's encephalopathy)
  Spinal cord lesions
  Familial dysautonomia
Orthostatic hypotension….
    Aging
    Drugs
       Tranquilizers; phenothiazines; barbiturates
       Antidepressants: tricyclics; monoamine
        oxidase inhibitors
       Vasodilators: prazosin; calcium channel
        blockers
       Centrally acting hypotensive drugs
       Adrenergic blocking drugs: phenoxybenzamine;
        labetalol
       Ganglion-blocking drugs: hexamethonium
       Angiotensin-converting enzyme inhibitors
Neurologic diseases
    Migraines- may lead to a vasovagal reaction
     secondary to pain,
    TIAs -Approximately 6%of persons with ischemic
     stroke or TIA have associated syncope
    Seizures- rare cause of syncope
                 -atonic seizures and sudden falls
                 associated with temporal lobe epilepsy
                 (temporal lobe syncope).
                - Unwitnessed grand mal seizures
                   may also be mistakaken for syncope
Decreased cardiac output

 Obstruction to flow
  Obstruction to LV outflow or inflow
      Aortic stenosis, IHSS (N-mediated or V
       tach)
      Mitral stenosis, myxoma

    Obstruction to RV outflow or inflow
      Pulmonic stenosis
      PE, pulmonary hypertension
      Myxoma
Other heart disease

  Pump failure (CHF; cardiomyopathy)
  MI (presenting symptom in 5% to 12% of
   elderly patients)
  CAD
  Coronary spasm
  Tamponade, aortic dissection
 Mechanisms could be V tach, bradyarrythmias,
   vasovagal reactions, sudden pump failure
Arrhythmias
    Bradyarrhythmias
        Sinus node disease
        Second- and third-degree atrioventricular block
        Pacemaker malfunction
        Drug-induced bradyarrhythmias
    Tachyarrhythmias
        Ventricular tachycardia
        Torsades de pointes (e.g., associated with
         congenital long QT syndromes or acquired QT
         prolongation)
        Supraventricular tachycardia
Diagnostic Evaluation
    Most important elements in the evaluation of
     syncope in the elderly are;
       determining whether the patient had
        syncope (distinguish from seizure,
        dizziness, coma, vertigo)
       risk stratification
       selective use of diagnostic tests to define
        the etiology of loss of consciousness
           history and physical examination, ECG,
            and risk stratification to guide further
            diagnostic tests.
History, Physical Examination, and Baseline
Laboratory Tests

     Detailed account of syncope, the events leading to loss of
      consciousness, and symptoms following the episode
     Orthostatic hypotension
     Cardiovascular findings - differences in BP (generally >20 mmHg)
      in the two arms are suggestive of aortic dissection or subclavian
      steal syndrome. Special focus for aortic stenosis, idiopathic
      hypertrophic subaortic stenosis, pulmonary hypertension,
      myxomas, and aortic dissection
     Neurologic examination
     H and P led to 40% of diagnoses

     Laboratory blood tests rarely yield diagnostically helpful
      information
        Hypoglycemia, hyponatremia, hypocalcemia, or renal
          failure are found in 2% to 3%
Further evaluation should focus on

    Arrhythmia detection
        Prolonged Electrocardiographic Monitoring
        Electrophysiologic Studies
   Tilt testing
  If multiple abnormalities causing symptoms,
   then try empiric therapy for these factors
   before extensive investigation
Evaluation of syncope
Prolonged Electrocardiographic Monitoring


   only 4% of patients had symptomatic
    correlation with arrhythmias
   In approximately 80%of patients, no symptoms
    occurred but arrhythmias were often found
    (causal relation therefore uncertain)
   In patients with high pretest likelihood of
    arrhythmias, further evaluation for arrhythmias
    needs to be pursued by event monitoring or
    electrophysiologic studies.
   Extending the duration of monitoring to 72 h
    may increase the yield of arrhythmias detected
Electrophysiologic studies (EPS)
    Predictors of V tach by EPS include organic heart
     disease, PVCs by ECG, and nonsustained V tach by
     Holter monitoring.
     Sinus bradycardia, first-degree AV block, and bundle
     branch block by ECG predict bradyarrhythmic
     outcome
    Negative predictors include the absence of heart
     disease; EF greater than 40%; normal ECG and Holter
     monitoring; absence of injury during syncope; and
     multiple or prolonged (>5 min) episodes of syncope
    Identify a group of patients who are at high risk of
     mortality- as high as 61% and sudden death rates of
     48%
Electrophysiologic studies (EPS)
Tilt testing

     Upright posture leads to pooling of blood in legs resulting in
      decreased venous return
      Normal compensatory response to standing up-right is reflex
      tachycardia, more forceful contraction of the ventricles, and
      vasoconstriction
     In individuals susceptible to vasovagal syncope, this forceful
      ventricular contraction in the setting of a relatively empty ventricle
      may excessively stimulate the cardiac sensory nerves
      (mechanoreceptors)
      Afferent impulses are relayed to the medulla, resulting in a
      decrease in sympathetic and increase in parasympathetic tone
     Use of provocative agents such as isoproterenol (avoid in elderly)
      or nitroglycerine because rates of positive responses without
      chemical stimulation appear to be low
Tilt testing
Other Tests
  Skull films, lumbar puncture, radionuclide brain scan,
   and cerebral angiography have not yielded diagnostic
   information for a cause of syncope in the absence of
   clinical findings suggestive of a specific neurologic
   process
  EEG shows an epileptiform abnormality in 1%, but
   almost all these are suspected clinically
  Head CT scans are needed if subdural bleed due to
   head injury is suspected or in patients suspected to
   have a seizure as a cause of loss of consciousness,
   but the yield is low when used in a nondirected fashion
Reasons for hospital admission.
    Admission for diagnostic evaluation:
    Known coronary artery disease, CHF Valvular or
     congenital heart disease
    History of ventricular arrhythmias
    Physical findings of heart disease (e.g., findings of
     aortic stenosis)
    Symptoms suggestive of arrhythmias or ischemia
    Associated with palpitations
    Chest pain suggestive of coronary disease
    Exertional syncope
Reasons for hospital admission…

    Admission for diagnostic evaluation: contd

    Electrocardiographic abnormalities
        Ischemia
        Conduction system disease (e.g., bundle branch block, first-
         degree atrioventricular block)
        Unsustained ventricular or supraventricular
         tachycardiaProlonged QT
        Accessory pathway
        Right bundle branch block with ST elevation in V1-V3
        Pacemaker malfunction

        Neurologic disease- New stroke or focal neurologic
         findings
Reasons for hospital admission…
    Admission for treatments:
    Structural heart disease
    Acute myocardial infarction, pulmonary embolism, other cardiac
     diseases diagnosed as causing syncope
    Orthostatic hypotension
    Acute severe volume loss (e.g., dehydration, gastrointestinal
     bleeding)
    Moderate to severe chronic orthostatic hypotension
    Treatment of multiple coexisting abnormalities
    Discontinuation or dose modification of offending drug
    Drugs causing torsades de pointes and long QT
    Drug reaction such as anaphylaxis, orthostasis, bradyarrhythmias
Treatment Selection
    Treatment should be reserved for elderly patients with frequent or
     disabling symptoms
    Screening for the psychiatric illnesses should be performed
     - often results in resolution of recurrent syncope
    Various drugs and pacemakers have been tried for patients with
     vasovagal syncope
    Very few controlled studies of drug therapy for neurally mediated
     syncope
         beta-blockers may inhibit the activation of cardiac
          mechanoreceptors by decreasing cardiac contractility
         anticholinergic drugs (transdermal scopolamine, disopyramide,
          paroxetine or theophylline)
          measures to expand volume (increased salt intake, custom-
          fitted counterpressure support garments from ankle to waist,
          and fludrocortisone acetate
Overall survival of participants with syncope




    Soteriades ES, Evans JC, Larson MG, et al. Incidence and prognosis of syncope. N Engl J

    Med. September 19, 2002;347(12):878-885  .
Thank You

								
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