Vertigo

Attacks of vertigo can indicate the part of the brain involved. The central form is  due to a disease originating from the central nervous system (CNS) often including lesions of cranial nerve VIII. 
The most common causes are inner ear infections or diseases of the ear such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis, and Meniere’s disease.
While  sometimes a one off episode it is more commonly a generally sudden hallucination of motion over hours or days,often with nausea,headaches or double vision.  Dizziness could also be a symptom of of a serious brain problem such as stroke, bleeding in the brain or multiple sclerosis. Attacks are a fairly common symptom and side effect of multiple sclerosis (MS), occurring in about 20 percent of people with MS at some point. 
Dizziness is often confused or used interchangeably. Feeling dizzy involves unsteadiness, light-headedness, uneasiness or fatigue whereas episodes of vertigo symptoms of spinning,sensation of movement or whirling can occur when one is not actually moving.  
Head movements and maneuvers such as Epley, Semont, Foster, and Brandt-Daroff techniques are often employed in diagnosis and treatment for vertigo

We  use peripheral vision automatically to maintain a stable spatial world in which to position ourselves to look around and see in line of sight  with central vision. The two visual systems work together, one giving stable spatial structure and the other gives central vision detail.
A mismatch can occur between reality and the signals your eyes, inner ears, and sense of touch are sending your brain
The four classic symptoms are vertigo, tinnitus, a feeling of fullness or pressure in the ear, and fluctuating hearing or hearing loss.

If the vestibular nerve has been damaged eg by a viral infection causing conditions jointly known as vestibular neuronitis, vestibular neuritis or labyrinthitis the result can be an infection of the vestibular nerve in the inner ear. As the vestibular nerve becomes inflamed, control and sense  of balance can suffer eg  chronic dizziness.

Dix Hallpike manoeuvre to diagnose BPPV

If no stroke or hypertension the most common peripheral form is benign paroxysmal positional vertigo (BPPV).
BPPV comes on quickly, causing disorientation and stumbling; some even fall out of bed. Most episodes last about a minute and recur over a period of a few days or weeks. ​
The Dix-Hallpike maneuver can differentiate an inner ear problem specifically as different types of BPPV cause different eye movements and elicit symptoms of dizziness during  a 45-degree head turn for at least 30 seconds.

The Head impulse is used as  certain rapid eye movements can indicate a problem in the semicircular canals of the inner ear.​ 
The Romberg test may show how vision will compensate for the loss of position sense as sway or fall  can occur  with eyes closed 

tumour workup
tumour symptoms
tumour implications

Causations can be from simple optical illusions  to complex brain tumours 
Integration of vestibular system, somatosensory and visual input to maintain posture and balance is required.
​Visual ,head and body movement training may be required.
Anything that disturbs this combination  can disturb our spatial stability, especially reduced visual acuity, field loss, stroke, head injury, 
The human ear is the key to dizziness. In the positional form  the eyes can provide clues. 
​A patient who has a problem with proprioception can still maintain balance by using vestibular function and vision.
In the Romberg test, the standing patient is asked to close his or her eyes.
​An increased loss of balance is interpreted as a positive Romberg’s test suggestive of mild lesions of the sensory, vestibular, or proprioceptive systems

 

Migraine headaches can bring on the dizzying sensation, as can lying in the magnetic field of an MRI machine. Meniere’s disease is caused by a buildup of fluid in the inner ear and can cause dizziness along with ringing in the ears and hearing loss,sometimes alleviated by a low sodium diet and a diuretic to decrease fluid pressure in the inner ear.​ 
Antiemetics such as meclizine may inhibit the nausea or vomiting that accompanies most types of the condition. 

​Smoothness of pursuit eye movements, horizontally and vertically, and loss of fixation or saccadic intrusions are important as eye movements are often the first sign of these conditions, and the most sensitive indicator of deterioration.

The visual sense can compensate for this loss of proprioception of muscle and joint position.
Proprioception, is the sense of the relative position of one’s own parts of the body and strength of effort being employed in movement.  it is provided by proprioceptors in skeletal striated muscles and tendons and the fibrous membrane in joint capsules.
If  caused by a dorsal column disorder, the patient may correct balance problems by opening his or her eyes.
If the lesion is in the cerebellum rather than the dorsal columns, the cerebellar ataxia of balance will not be corrected by visual compensation, as is the case in the sensory ataxia of the dorsal column.
Vertigo can be be concurrent with paralysis 
Radiation treatement Pre and post surgery 

Benign paroxymal positional vertigo (BPPV)

BPPV can occur when calcium builds up in canals of the inner ear  usually brought on by trauma to the head or by moving the head in certain positions.
The majority of peripheral vertigo is caused by otoconia (also called canaliths), tiny limestone and protein crystals that reside deep inside your ear in the vestibule dislodge from external motion to the gel in the utricle  and migrate into one or more of the 3 fluid-filled semicircular canals instead.

The most commonly used and successful physical therapy for BPPV and treatment  is the Epley manoeuvres  (also known as a canalith repositioning procedure).  The goal is to return the dislodged otoconia to the vestibule to lessen risk of falls and driving accidents utilising  head positions designed to remove or shift inner ear ‘crystals’ in BPPV

Other treatments helping to control balance include  
calcium channel blockers, beta blockers and tricyclic antidepressants.

  • migraine prevention medication.
  • medication to dampen the sensations of dizziness.
  • anti-nausea medication.
  • Vestibular compensation and vestibular rehabilitation
  • Training the brain to cope with the disorientating signals coming from the inner ears by learning to rely more on alternative signals coming from the eyes, ankles, legs and neck to maintain balance.​

Diagnosis can be made by magnifying and measuring rapid eye movements with high definition recording googles during dizzy spells as crystals in the  ear are moving in and out of place (  eg  a nystagmus – an uncontrolled movement of the eye)  the eye movements  with physical therapy can be measured.
​This  may result to maintain orientation eg during the Fakuda step test which requires body  movements with the eyes closed to see if the body strays from the midline where affected by the condition.