New-onset refractory status epilepticus in an adult with an atypical presentation of cat-scratch disease: successful treatment with high-dose corticosteroids.

New-onset refractory status epilepticus (NORSE) is defined as a sudden onset of refractory status epilepticus in patients who do not have a history of epilepsy. It is a neurologic emergency, and determining the underlying etiology is an important factor for effectively managing and predicting the prognosis of NORSE. We describe the case of a 28-year-old woman who was hospitalized with NORSE secondary to an unknown etiology. She did not respond to traditional anticonvulsant therapy, including benzodiazepines, fosphenytoin, propofol, and levetiracetam. The patient was placed on continuous electroencephalography (EEG) monitoring and was treated further with multiple antiepileptics, which were titrated aggressively based on EEG readings and therapeutic drug levels; despite this treatment, EEG monitoring revealed continued seizures. Thus, high-dose corticosteroids were started for seizure control. Her workup included computed tomography and magnetic resonance imaging of the head, a lumbar puncture, toxicology screening, and extensive testing for multiple infectious and inflammatory etiologies. The patient's history revealed recent exposure to a new cat. Serologic results were positive for Bartonella henselae, and she was diagnosed with cat-scratch disease (CSD). She did not have the typical presentation of symptoms of lymphadenopathy, however, which is common in CSD. Doxycycline 100 mg and rifampin 300 mg twice daily were added to the patient's anticonvulsant and corticosteroid therapy. She was hospitalized for a total of 26 days and discharged with only minor neurologic impairment (short-term memory deficits and minor cognitive problems). The patient was discharged receiving antiepileptics, antibiotics, and a corticosteroid taper. To our knowledge, this is the first clinically known case of NORSE secondary to CSD without typical CSD symptoms in the adult population. The patient failed to respond to traditional anticonvulsant therapy alone. With the addition of high-dose corticosteroids to aggressive anticonvulsant therapy, seizure control was achieved. Further studies are needed to determine the effectiveness of high-dose corticosteroid and anticonvulsant therapy followed by antibiotics in patients with NORSE secondary to CSD.