We report a 74-year-old man with a lung cancer, who developed right leg weakness, neurogenic bladder, and multiple cranial nerve palsies. The patient was well until December of 1992, when he was 74-year-old, when he noted transient double vision; in February of 1993, he noted numb sensation and weakness in his right leg. Later in the same month, he developed overflow incontinence of urine and weakness in his right face. He also noted deafness in his left ear (he had a marked loss of hearing in his right ear since childhood because of otitis media). His weakness in his right leg had progressed, and he was admitted to our service on March 19, 1993. On admission, he was afebrile and BP was 130/50 mmHg. General physical examination was unremarkable. On neurologic examination, he was alert and oriented to all spheres; no dementia was noted nor were detected aphasia, apraxia, and agnosia. His optic fundi were unremarkable; ocular movement appeared normal, however, he complained of diplopia in far vision. Sensation of the face was intact. He had right facial palsy of peripheral type; he was unable to close his right eye, and Bell's phenomenon was observed on attempted eye closure. On the left side, he had facial spasm. He had marked bilateral deafness. He had no dysarthria or dysphagia. The remaining of the cranial nerves were intact. Motor wise, he was unable to stand or walk alone; weakness did not appear to account for his difficulty in gait; manual muscle testing revealed 4/5 weakness in his tibialis anterior muscle, 1/5 in the peroneus longus, 0/5 in his extensor hallucis longus and extensor digitorum longus, all on the right side. Brachioradial and quadriceps femoris reflexes were increased to 3/4; plantar response was equivocal on the right side, and flexor on the left. Sensory examination revealed loss of touch and pain sensation in the L5 and S1 distributions in his right leg: vibration and position sensations were also diminished in his right foot. He had overflow urinary incontinence with loss of bladder sensation. Marked nuchal stiffness was noted, however, no Kernig's sign or eye ball tenderness was present. Pertinent laboratory findings were as allows; WBC 8,100/microliters, Ht 42.5%, platelet 326,000/microliters, TP 6.8 g/dl, BUN 16 mg/dl, creatinine 0.54 mg/dl, glucose 95 mg/dl, Na 136 mEq/l, K 4.4 mEq/l, Cl 100 mEq/l; liver profile was normal; CEA 436.6 ng/ml, CA19-93 U/ml; urinalysis was normal.(ABSTRACT TRUNCATED AT 400 WORDS)