Bruns nystagmus is an unusual type of bilateral

nystagmus Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. Due to the invol ...

most commonly occurring in patients with cerebellopontine angle tumours. It is caused by the combination of slow, large amplitude nystagmus (gaze paretic nystagmus) when looking towards the side of the lesion, and rapid, small amplitude nystagmus (vestibular nystagmus) when looking away from the side of the lesion. It occurs in 11% of patients with

vestibular schwannoma A vestibular schwannoma (VS), also called acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve that passes from the inner ear to the brain. The tumor originates when Schwann cells that form the insulating myelin sheath o ...

, and occurs mainly in patients with larger tumours (67% of patients with tumours over 3.5 cm diameter). Bruns nystagmus is also associated with an increased incidence of balance disturbance in patients with vestibular schwannoma. It may be caused by the compression of both flocculi, the

vestibular The Vestibular (from pt, vestíbulo, "entrance hall") is a competitive examination and is the primary and widespread entrance system used by Brazilian universities to select the students admitted. The Vestibular usually takes place from Novem ...

part of the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

, and improvement in both the nystagmus and balance problems occur commonly after removal of the tumour. Bruns nystagmus is named for Ludwig Bruns (1858 – 1915).

References

{{reflist Medical signs Disorders of ocular muscles, binocular movement, accommodation and refraction