Many patients have balance abnormalities that can be related to eye functions. There are connections in the brain stem between nuclei which serve balance – the vestibular nerve which goes to the semicircular canals in the ear, receptors in muscles in the neck as well as the eye muscle motor nuclei. These connections help keep eyes in line as we hold our head in different positions. When input from peripheral muscles become unbalanced from one side to another, patients can feel as if they are dizzy. There is a group of people who feel light-headed and a group of people who feel as if the room is spinning. Some of these people who feel light-headed have problems with their cardiovascular system. Work-ups involve testing blood pressures and pulse both seated and standing, in addition to tests of their heart and carotid. Patients who feel as if the room is spinning may have problems due to overaction of the receptors in their semicircular canals. Sometimes this involves an imbalance in the sodium metabolism of the fluid. It can be corrected with drugs, including hydrochlorothiazide, spironolactone, and injectable triamterene.
Other patients have a feeling of uneasiness as they look to the side. They feel as if their balance is off. These patients can benefit from different classes of drugs. One class can relieve the symptoms by slowing the firing of the nerves. Benzodiazepines such as clonazepam help with this. Long term help can be obtained with the neurotransmitter GABA, either with Neurontin or Lyrica.
The first thing done to correct these problems is a thorough neuro-ophthalmic exam. The patient is examined for evidence of nystagmus and for eye movement disorders. Prisms are used to correct the imbalance as are exercises. There are basically two types of exercises: exercises for the vestibular system and exercises for the eye muscle system. Both are useful. The goal is to eliminate the feeling of uneasiness with drugs and exercises and to gradually reduce the need for prisms and medications.