Vertigo

Vertigo is the sensation that you, or everything around you, is spinning. Often incorrectly used as the term to describe the fear of heights (this is acrophobia), vertigo can affect your balance to such a degree that you find it difficult to perform everyday tasks and is often associated with the feeling of nausea, vomiting or sweating.

A vertigo attack can last anywhere from a few seconds to hours to even months in severe cases. You should make an appointment with your GP if you have vertigo that won’t go away or keeps reoccurring.

There are a wide range of conditions that can cause vertigo and it is therefore very common. In fact, it is one of the most likely reasons for people to visit their GP, with as much as 40% of people aged over 40 going on to experience vertigo. Nearly always, it is caused by an inner ear infection (Labyrinthitis), a migraine, head injury or it may even just be triggered by specific changes in the position of your head.

Spotting the difference between vertigo and dizziness

Vertigo is more than just feeling dizzy. Many people use the terms dizziness and vertigo interchangeably. However, under strict medical terminology, this isn’t quite correct. Dizziness is usually characterised as a feeling of light-headedness as if you are about to faint. Dizziness (without the sensation of spinning) is likely to be caused by low blood sugar or dehydration, irregular heart rate or low blood pressure.

Vertigo, on the other hand, is the false impression of a spinning motion when you are in fact standing or sitting still OR a misperception of a familiar motion such as walking. For example, if you are walking in a straight line along a tile floor and you feel as if you are sinking into the ground, this is defined as vertigo.  Vertigo is normally the result of a problem with the inner ear (inner most part of the ear) or the nerves that surround this area, as this part of the ear is responsible for balance as well as sound perception.

In extremely rare cases, both vertigo or dizziness can be symptoms of leukaemia. However, this blog will focus on vertigo and how and why, in very unusual cases, can be a sign of leukaemia.

Vertigo and leukaemia

There are a very small number of cases in scientific literature where vertigo is described as being the first symptom of leukaemia. It is more likely (but still very rare) to occur as a late, and highly serious symptom, that may occur when leukaemia is left untreated or you are very delayed in receiving a diagnosis. In contrary to this, up to almost half (16-48%) of leukaemia patients will present with symptoms involving disrupted ear function at some stage of the disease after diagnosis, including either; vertigo, sudden hearing loss or tinnitus.

How does leukaemia cause vertigo?

Vertigo in leukaemia is usually caused by an abnormally high number of white blood cells in the blood (hyperleukocytosis) which can occasionally cause the blood to thicken and clog up the small vessels (leukostasis). It is thought that if the vessels surrounding the nerves of the inner ear are blocked, they stop working properly which leads to a group of symptoms known collectively as hyperviscocity syndrome. This can include vertigo, sudden hearing loss or tinnitus depending of which nerves are disrupted in the inner ear. For example, obstruction of the ‘labyrinthine artery’ can cause sudden hearing loss. It is the blockage of the small blood vessels surrounding the ‘vestibular nerve’ that is thought to lead to vertigo in leukaemia patients.

Differences in occurrence between chronic and acute leukaemias

Generally speaking vertigo and other inner ear related symptoms are more common in patients with acute leukaemia rather than those with chronic leukaemia.

In particular, vertigo tends to be most prevalent in people with AML (acute myeloid leukaemia). This is because the cancer cells in AML (called blasts) are larger than normal white blood cells and so have more difficulty passing through the small blood vessels in the inner ear.

However, just because your white blood cell count is very high, this doesn’t mean you will experience vertigo. An abnormally high white blood cell count (hyperleukocytosis) is common in both chronic myeloid leukaemia (CML) and chronic lymphocytic leukaemia (CLL) however, vessel blockage (leukostasis) and the related symptoms are extremely rare in these patients.

Likewise, the frequency of hyperleukocytosis in people with ALL (acute lymphoblastic leukaemia) is between 10-30% but rarely does this result in noticeable symptoms. Other possible causes of vertigo in leukaemia patients are thought to include bleeding in the middle and inner ear or inflammation due to infection (increased bleeding and repeated infections are common symptoms of leukaemia).

Treatments of Vertigo

The treatment for vertigo depends on the underlying cause. In a lot of cases, vertigo goes away without any treatment because your brain can adapt to changes in the inner ear to help compensate for any loss of balance.

Possible treatments can include:

• Antibiotics – If your vertigo is being caused by an infection your GP will prescribe these.
• Antihistamines – For short term relief to reduce inflammation of the inner ear.
• Medications such as meclizine and benzodiazepines can help to relieve vertigo OR prochlorperazine and domperidone can relieve feelings of nausea.

• Head movement exercises – A technique called the ‘Epley maneuver’ can help to temporarily resolve vertigo. It involves manoeuvring the position of your head so that gravity can correct the flow of fluid within the inner ear.

Balance therapy or ‘vestibular rehabilitation’ involves undergoing certain exercises to help make you less sensitive to the perception of motion.

• Water pills – You may be prescribed water pills (diuretic) to help rid the body of excess water. This along with a low-salt diet will lower fluid levels within the inner ear, to help improve symptoms.

Treatment for leukaemia-induced vertigo

 Some of the above treatments may be given to provide quick relief to leukaemia patients, however, if a leukaemia diagnosis is made, the underlying problem of excess level of white blood cells must be treated. Due to the rarity of vertigo in leukaemia, there are no standard protocols for its treatment in patients, and there is debate over which method is most effective.

Possible treatments include;

• Leukapheresis and chemotherapy- Leukapheresis is a procedure in which blood is briefly taken out of the patient and the white blood cells are selectively removed. This technique has been shown to be more effective when performed alongside high doses of chemotherapy.
• Intrathecal methotrexate– Methotrexate (chemotherapy) is sometimes injected into the spinal canal (intrathecal injection) in cases of sudden hearing loss to reduce levels of leukemic cells in the cochlea (part of the inner ear involved in hearing).
• Radiotherapy of the middle and inner ear – Sometimes the inner ear can be hard to reach with chemotherapy. The anatomical structure of this area itself can sometimes act as a protective shelter for leukaemia cells. Radiotherapy is therefore sometimes needed to ensure all the leukaemic cells are completely killed off to relieve symptoms.