Cape Town:  021 201 1119  

Dizziness and other conditions

What does it mean if I get dizzy?

Dizziness is a symptom that can result from many causes, one of them being the blood supply to the brain.  Other more common causes include:

Orthostatic hypotension:
-  This is a drop in the blood pressure when changing position - for example, from sitting to standing.

Medication
-  Especially medication that lowers your blood pressure

Cardiac causes
-  Abnormal rhythms of the heart

Ear problems
-  Inner ear disorders

Brain problems
-  Benign central nervous system problems

Vascular causes
-  Decreased blood flow to the brain from blockages in the arteries
-  Peices of plaque causing blockages in the brain
-  Blockages in the arm arteries which may then divert blood away from the brain
-  Spinal disease of the neck - pieces of bone may compress the blood vessels that supply the brain with oxygen

Other symptoms apart from dizziness that occur with vascular problems include:

  • Double vision
  • Unable to walk in a straight line
  • Difficulty speaking or formulating words
  • Ringing in the ears
  • Numbness around the mouth
  • Numbness in different parts of the body
  • Drop attacks

Symptoms usually affect both sides of the body.  It is very important to have them checked out if ≥2 are present.

How does a vascular problem cause symptoms like dizziness?

There are 4 blood vessels to the brain.

  • Two carotid arteries on either side of the neck in the front.
  • Two vertebral arteries that run up with your spine to supply the posterior part of the brain.

dizziness1

These arteries all connect in the brain so that if there are problems with one artery, the others can compensate.  All arteries may be affected by atherosclerosis. The risk factors for atherosclerosis are:

  • Diabetes
  • High blood pressure
  • Smoking
  • High cholesterol or high lipids
  • Older age
  • Increased body mass index
  • Sedentary lifestyle

In the neck vessels, the nature of the plaque (how soft or hard) is more important than how much narrowing it causes.  In fact, if a persons arteries all connect, then 3 vessels can be diseased and the brain is still able to function on one vessel!  The problem arises when not all the arteries are connected or when pieces of a plaque break off and travel to the brain.

The symptoms mentioned above may be occur if the vertebral arteries are not connected to the front carotid arteries. If there is a narrowing of one or both of the arteries, you may feel dizzy (or other symptoms mentioned above) when your blood pressure drops low or when you turn your head in a certain direction and the artery gets compressed.  This compression may occur if you have spinal problems in the neck. This, in turn, restricts the amount of blood flow to the posterior part of the brain and that is why you get those specific symptoms.  This usually last for a short period, and when the blood flows again, you return to normal.  These are more of a nuisance than anything else. They may be a danger if you are driving or working with machinery and should be investigated.

Other reasons for the symptoms are the same as described for stroke, the difference is that atherosclerosis and plaque formation is in the posterior arteries and not the carotid arteries. If the plaque is unstable (or soft) pieces may break off and lodge in smaller arteries in the posterior brain, preventing oxygen flow to those cells.

Occasionally all 4 arteries supplying the brain may be narrowed and at times not enough blood will reach the brain. This is a problem if all the arteries are not connected.
This is not common and requires investigation.

How will I be investigated?

Dizziness and various other posterior circulatory symptoms are common in the elderly population.  Sometimes atherosclerosis can be found on arteries, but it doesn’t mean they need to be treated.

In order to treat the right condition and not to treat unnecessarily, it is important to look at all the causes of these symptoms.

  • Your doctor will need to check your blood pressure when you are sitting and standing as well as feel all the pulses in your arms and neck.
  • Your medications will need to be reviewed – and often adjusted.
  • Your heart will need to be assessed – you may need to see a cardiologist.
  • Your ears will need to be looked at - you may need to see an ENT surgeon.
  • Your brain needs to assessed – you may need to see a neurologist.

These are all important aspects of your body to be looked at because you don’t want to have any unnecessary surgery, that may put you at risk of a stroke.

Finally, in order to assess the blood vessels a duplex doppler ultrasound of the neck is necessary. This will look at the all the blood vessels supplying the brain – if there is any disease present, if there is any narrowing and at the direction of blood flow.

 

Contacts

Room 1521 Christiaan Barnard Hospital, Cape Town, 8001.

  Cape Town Switchboard:  021 201 1119