One of the most striking symptoms of perpendicular hallucinosis is the existence of very vivid, colorful, and recurrent visual hallucinations. These hallucinations occur due to lesions of the brainstem and thalamus, which can influence a disinhibition of the lateral geniculate nucleus. The hallucinations provoked can be very debilitating for the person suffering from this illness and can completely disassociate him from reality.
