Poisoning or primary nervous system disease?--difficulties of the differential diagnosis exemplified by four different clinical cases.

Acute or chronic injury of the nervous system caused by xenobiotics can resemble primary disorders of the nervous system. In this study, four different cases that are characterized by unclear clinical presentation have been discussed; they required a detailed differential diagnostics using modern radiologic and electrophysiologic studies. Case 1. A young alcohol abuser was referred to the Acute Poisonings Unit at Wrocław with a presumptive diagnosis of methanol poisoning. Neither methanol nor ethylene glycol were detected in patient's serum and urine. During hospitalization in our ward he lost vision completely, and neurologic examination was consistent with a transverse spinal cord injury. Traumatic spinal cord injury coexisting with methanol poisoning, or even Devic's syndrome were considered in differential diagnosis. The MRI did not reveal a spinal cord injury, and the EMG showed severe demyelinating-axonal polyneuropathy. Finally the patient was diagnosed with methanol poisoning complicated by both loss of vision and severe alcoholic polyneuropathy. Case 2. A 27-year-old man was found unconscious in a street. A head CT revealed numerous small intracerebral hemorrhages, and patient's urine contained high concentration of amphetamine. A presumptive diagnosis of amphetamine poisoning complicated by intracranial hemorrhage was proposed. The repeat head CT revealed traumatic injury of the skull in a form of depression. Based on this result, the patient was diagnosed with a posttraumatic intracranial hemorrhage. Case 3. A young man with history of schizophrenia was transferred to our ward from a psychiatric hospital with a presumptive diagnosis of neuroleptic malignant syndrome complicated by rhabdomyolysis. Infection of the nervous system and focal lesions in the brain were ruled out with help of lumbar puncture and a brain MRI. After having obtained additional details of patient's history, it appeared that the patient had not been taking neuroleptics, and therefore it was assumed that patient's condition be connected with a catatonic type of schizophrenia exacerbation. Case 4. A 17-year-old woman, who returned from a disco club, presented with a bizarre behavior, she spoke incoherently, and she saw everything in bright and intense colors. Then she experienced a severe seizure attack with loss of consciousness and apnea. Toxicologic tests were negative. The patient was referred to neurology where she was finally diagnosed with epilepsy, and the attack was induced by strobe lights in a disco club.