Posts Tagged ‘syncope evaluation’

Dizzines , giddiness , light headedness , fear of fall or true fall (Syncope) are the  most common symptoms beyond middle  age .They usually end up with consulting physicians , neurologists and cardiologists .Cervical disc is commonly blamed for this.While all these symptoms can be a manifestation of cervical disc , true syncope seems to be rare with cervical spinal disorder.

how common is suncope in cervical spondylosis Why true is  syncope rare with  cervical spinal narrowing ?

There is a fundamental ignorance here. We are not yet clear  whether giddiness /dizziness is neural or vascular .(Or combinations of both ) in cervical spinal disease.

Many of the patients experience momentary unsteadiness and feel like falling but very rarely end up in a fall or syncope.By definition syncope requires global transient hypoperfusion of brain to trigger a fall .

Cervical canal carries only the vertebral artery .Both internal carotids are no where near the spine. So, however severe the vascular compromise within the cervical canal , syncope is unlikely as anterior cerebral circulation compensates at the level of circle of Willis. Is that the correct way of reasoning ? Unilateral vertebral compromise rarely matters as other side takes care.It is very unlikely both vertebral artery get compromised by cervical spinal spurs simultaneously.

How many seconds of vascular compromise is  required to produce syncope ?

Brain seems to be a funny and sensitive organ .In erect posture it is very sensitive. It reacts  in a  fraction of time for any transient reduction of blood flow.The same cardiac events which can cause symptoms of impending syncope in erect posture is quiet comfortably tackled in recumbent posture .

In erect posture , blood pressure need to much higher to get it pumped above the heart against the gravity. Though , it seems absolute blood pressure and cerebral perfusion that matters, there is something more we are missing.  The brain-stem -vestibular system perceives differently when a recumbent person develop cerebral ischemia than when he is erect . The reflex circuit that activates on/off switch  for abrubt loss  generalised muscular tone is not yet been identified .

It is a biologically  heartening irony that syncope is a natural counter mechanism by which  the organism assumes instant recumbent position to maintain perfusion of brain .A fall promptly does this.(Ofcourse with a risk of Injury )

We think more than 3 second pause will initiate a  syncope circuit .But it is not a fixed number. Some can tolerate up to 5sec or even more especially in lying posture.

Final message

Syncope , as such in isolated cervical spondylosis is rare even though it can potentially interfere with  the vertebro basilar system .Why the vascular compromise almost always fall short of syncope and end up with just momentry unsteadiness is not clear.

Further queries to be addressed

Is dizziness, giddiness , presyncope  are vascular or neural  event?

Can vertigo occur with cervival spine disease ?

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Recently , I came across a   young women  who underwent the following three tests for one episode of syncope after witnessing her pet dog bleeding with  an Injury !

  1. Carotid doppler
  2. Holter monitoring and event monitors
  3. Brain MRI /MR angiogram

This was followed up  by Head up tilt(HUT)  in a premier hospital

After 1 week of investigation ,a diagnosis of  Neurocardiogenic syncope was made and she was reassured and no drugs were prescribed.

(The collective yield of the above three investigation in fixing  a specific diagnosis is  less than 10 % of all known causes of syncope )

Syncope  approach  evaluation

To diagnose  common syncope . . . we need common sense !

Syncope is a dramatic  symptom.It is one of the commonest symptom in ER as well . Life time incidence of syncope is at least one episode in 50% all human life ! The definition  of syncope until recently , was liberal .Any transient loss of consciousness with spontaneous recovery  was termed syncope.

This includes

  1. Hypoglycemia
  2. Anemia
  3. Siezure disorders
  4. Structural  neurogenic (Including ,  brain tumors , Dural hematomas etc )
  5. Panic attacks (psychogenic)

Cardiologists wanted to fix syncope as an exclusive disorder of  circulatory insufficiency.By bringing in a modification in the definition  , ie  syncope is  now defined as a transient loss of consciousness due to   reduction in cerebral perfusion  .

This definition helped cardiologists  to exclude the above entities . Still many would include all in single basket as patient should be seen as a whole and we can’t expect them to  land according to our convenience and classification.

Here is an incomplete* list about causes of  syncope (* 99% complete ?)


  • Vaso- vagal syncope in young ( Neuro-cardiogenic , Common , Benign)
  • Autonomic dysfunction of elderly ( Including postural hypotension )


Arrhythmic ( Sinus node dysfunction /CHB/Idiopathic VT/Long QT syndromes)

Structural heart disease

  • Valvular  heart disease  (LVOT/RVOT obstructions)
  • Myocardial disease
  • Rarely ischemic heart disease


  • Severe pulmonary hypertension (Including PPH ,  pulmonary Embolism )
  • Paradoxical embolism.
  • Aortic arch disease -Takayasu related arteritis .


We have a sophisticated array  of investigation for syncope .It can be a never ending exercise , ranging from  spinal cord evoked potentials to diagnose Shy-drager syndrome ,   . . .  to implanting long-term loop recorders to decode  heart beat behavior.

However , evaluation of syncope is the ultimate wake-up call  to all current generation cardiologists  . . . Why clinical cardiology  should  never  be allowed to die (and  it  will not ! )

Common sense begins with answering  few simple questions . Is it really syncope ?

If  you ask this question three times and with  specific leads to the patient  and the witness ,  truth will come out  . 90% of times it may not be syncope at all (Near syncope, accidental  fall, dizziness ,extreme blurred vision, drowsiness  etc)

If it is syncope , Is there a non cardiac cause ?

It may related to the Hypoglycemia / Anemia /Panic attacks.Get a neurologist opinion , it would be terrible mistake if you miss a space occupying lesion  within the brain. (Missing chronic silent sub dural hematomas is  frequent   in the evaluation of syncope of elderly !)

Ruling out  cardiac syncope is relatively easy

In the remaining  patients  basic investigation like routine blood tests,ECG, ECHO   will help us  rule out most serious cardiac disorders.Similarly  bulk of the electrical cardiac syncope can be diagnosed.(Holter , carotid study in selected few )

Need for neurologist -cardiologist interaction.

Syncope due to VBI,  transient Ischemia attack , Senile vascular dementia  is a grey zone . Many have complex neuronal -vascular mechanisms . What is Consciousness ?  and  What is LOC ?  :Is it the lack of blood or severely depressed nerve signal in the reticular activating system? Lots of interaction between cardiologist and neurologist is required to clear our ignorance.(I  have one such  elderly patient who is intermittently awake ! I call this chronic syncope !)  .

Undiagnosed syncope is not  a crime

Realise the most important lesson in Medicine . If you  have ruled out all serious  causes of syncope you should have the courage to be satisfied with that !

Scientific pursuits has a limit. Searching for the mechanism of a psychogenic  fainting attacks with intra cerebral electrodes is a clear case of  physician acquiring a psychotic  behavior !

Final message

Syncope is not only a dramatic symptom for the patient , it also unfolds a drama of costly  investigations  . .  . many  with  dubious value.

Talk to the patient personally for  10 minutes in a quiet room, try to apply that elusive  clinical sense  . . .   it would rarely let you down !

After thought

What is the true clinical value of * Head up tilt Test (HUT)?

Will be posted soon

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