Other findings that suggest a physical cause include Abnormal vital signs (eg, fever, tachycardia, tachypnea) Meningeal signs and symptoms (eg, headache, photophobia, neck rigidity) Abnormalities noted during the neurologic examination, including aphasia Disturbance of gait, balance, or both Incontinence Some findings help suggest a specific cause, especially when symptoms and signs are new or have changed from a long-standing baseline: Dilated pupils (particularly if accompanied by flushed, hot, dry skin): Anticholinergic drug effects Constricted pupils: Opioid drug effects or pontine hemorrhage Rotary or vertical nystagmus: Phencyclidine intoxication Horizontal nystagmus: Often accompanies diphenylhydantoin toxicity Garbled speech or inability to produce speech: A brain lesion (eg, stroke) A preceding history of relapsing-remitting neurologic symptoms, particularly when a variety of nerves appear to be involved: Multiple sclerosis or vasculitis Stocking-glove paresthesias: Possibly thiamin or vitamin B12 deficiency In patients with hallucinations, the type of hallucination is not particularly diagnostic except that command hallucinations or voices commenting on the patient's behavior probably represent a mental disorder.