By Dr Ian Lawson BChiroSc, MChiroprac
Do you suffer dizziness? If so, you’re not alone. Symptoms of dizziness are amongst the most common symptoms we see in practice here at the Chiro Health & Rehab Centre every day.
The question is, what causes it? And more importantly, WHAT CAN BE DONE ABOUT IT?
Before I explain anything, let me offer you this: if you suffer from dizziness, send me an email (email@example.com) with something in the subject line about dizziness (eg. “Free dizziness assessment”), and mention this blog post, and I will give you a complimentary assessment (either by email or in person at the clinic) of your dizziness and chat about how we might be able to help you, completely free of charge or obligation.
Now, onto the fun stuff!
The first thing to know is this: How would you describe the dizzy feeling? Do you feel;
a) Light-headed, as though you are about to faint? or;
b) A sensation of movement (usually described as a ‘spinning’ feeling)?
The answer to this question goes a long way to differentiating the causes.
a) Light-headedness or ‘near-faint dizziness’ is an issue of fuel delivery. In other words, not enough oxygen or glucose is getting to the brain and you start to feel faint. This can be due to a cardiovascular issue (if so, a heart test or blood pressure check would be in order), or a condition known as orthostatic hypotension (ie. a drop in blood pressure when the nervous system doesn’t respond to a change in posture, for example when going from sitting to standing quickly). Light-headedness may also be caused by a range of external influences such as medication, stress, alcohol, etc.
b) A sensation of movement is what we call vertigo. Vertigo has a number of different causes, none of which we’ll explain greatly here, lest this become more of an essay than a quick blog read! As an overview, we need to determine whether vertigo is caused by a problem within the vestibular apparatus (the inner ear), or in the brainstem.
Common causes of vertigo related to the vestibular apparatus
The main causes of vertigo that can be attributed to dysfunction of the vestibular apparatus are:
- Benign Paroxysmal Positional Vertigo (BPPV): This occurs when small crystals embedded within part of the vestibular apparatus become dislodged and make their way into the semicircular canals (where they shouldn’t be!) This effectively causes nerve signals from the vestibular apparatus to the brain to become amplified, and so movements of the head bring on an increased sensation of movement. The dizzy spell typically only last for 10-20 seconds, and is related to a positional change of the head (eg. rolling over in bed, looking down for a while then looking up, etc.) If the dizzy spell lasts any longer than 20 seconds it’s highly unlikely to be BPPV. If it is BPPV, a simple manoeuvre caled the Epley Manoeuvre can be carried out to correct it. In most cases, it only takes one or two applications of this techniaue to fix the problem.
- Meniere’s disease: This condition will be characterised by the classic triad of symptoms: vertigo, tinnitus (ringing in the ear), and hearing loss. The dizzy spells last longer in this condition, more like several minutes at a time.
- Infection (eg. acute otitis media or vestibular neuronitis): You’ve probably all heard of someone getting an inner ear infection, and the biggest effect is vertigo and a loss of balance. Again, dizzy spells last longer in the case of infection, and there is usually a history of a recent infection elsewhere in the body (commonly an upper respiratory tract infection).
- Acoustic neuroma: The 8th cranial nerve (the vestibulocochlear nerve) is the one that relays all vestibular signals AND sound information from the vestibular apparatus and the cochlea into the brain. This nerve is surrounded by a nerve sheath, and can become susceptible to the growth of a neuroma. This slow growing tumour will be responsible for the onset of dizziness and hearing loss over the course of years as it slowly compresses the nerve and inhibits nerve signals from travelling along it properly. It needs to be diagnosed by an MRI, and audiometry is frequently used to confirm the hearing loss prior to this (audiometry is also used when diagnosing Meniere’s disease).
The main causes of vertigo that can be attributed to dysfunction of the brain or brainstem are:
- Multiple Sclerosis(MS): MS is definitely a consideration for vertigo sufferers, particularly if there have been episodes of dizziness in the past that have come and gone, or other neurological symptoms in the past that have seemingly spontaneously resolved themselves. It is also most common in caucasian or Mediterranean females aged between 20-50. MS attacks the myelin sheath that covers nerves and affects nerve transmission, showing up in a myriad of symptoms, of which attacks of vertigo can be one.
- Migraine: Yep, migraine. The more research we do into the brain the more we see that the neurological dysfunction that we classify as migraine is responsible for MANY different symptoms (not just headaches!) Headaches are just one of the many symptoms of migraine: vertigo is another. But that’s the topic of a whole separate blog entry.
- Vascular lesion: Damage to the vertebral artery (which supplies 30% of the blood to your brain) will lead to an alteration in the transmission of nerve signals and an alteration of perception of your position in space. This leads to dizziness as the brain isn’t exactly aware of the body’s location in relation to the environment around it. This also covers vascular lesions that have damaged the blood flow to the cerebellum, a part of the brain that is intricately involved in balance and co-ordination.
- Tumour: While rare, a space occupying lesion (ie. tumour) of the brainstem area must be considered as a potential causative factor in anyone with dizziness. This will usually correlate with a number of other history findings, and must be investigated with an MRI. Brainstem tumours are more common in children than in adults (adults tend to get tumours in higher areas of the brain, kids tend to get them in deeper areas of the brain such as the brainstem). Again, these are rare and anyone with dizziness SHOULD NOT assume they have a tumour! We’re not trying to scare anyone here…
And finally, we must consider this: Impaired cervical sensorimotor control
We’ll probably cover this in a blog post of its own too, but the basic premise is this: your brain is aware of your body’s position in space (and any movement thereof), not just from one sensory input, but a combination of THREE main sensory inputs. These three sensory inputs are:
- Vestibular System
- Proprioception (joint position sense, especially from the upper part of the neck)
These 3 inputs converge onto the brainstem, and if all 3 are in agreement (ie. they’re all telling the brain the same thing regarding where the body is currently positioned in space), then a state of normality exists and there will be no sense of vertigo. If one of these 3 sensory inputs is a bit off, the brain can cancel that out and ignore it, and go with the other 2. If, however, there’s a mismatch between all 3 or a significant difference from one of them, a state of ‘unawareness’ ensues and the person will normally experience some vertigo.
Hence, improvement of the sensory information from the upper part of the neck (and rest of the body as a whole) with the aim of normalising these 3 sensory input systems will lead to a decrease in dizzy sensations. Isn’t it a good thing that chiropractic adjustments primarily enhance proprioceptive inputs into the brainstem?
This is one of the main ways that chiropractic can help with dizziness. Improving cervical (neck) proprioceptive feedback through adjustments to this area, will lead to an improvement in sensorimotor control and a greater sense of awareness of the body position in space, and any movement happening therein. A decrease in dizziness is commonly experienced through our treatment.
There’s probably a whole lot I haven’t covered here, but I hope that has given you a bit more insight to one of the most common symptoms we see.
Oh, I forgot to mention one more cause of dizziness: staring for too long at the picture below will DEFINITELY cause dizziness. The solution? Don’t look at it! But just try and take your eyes off it, it’s not easy, hey?!