BACKGROUND: Infection with tick borne Borrelia Burgdorferi (Lyme disease) can without treatment rarely develop into a chronic phase. Secondary Normal Pressure Hydrocephalus (sNPH) based on chronic infection with Borrelia Burgdorferi (Bb) is an even rarer entity, that with the right treatment is potentially curable.

CASE PRESENTATION: A 67-year-old male with a slow onset of progressive balance problems, also presented unspecified dizziness, urge feeling, neck soreness and discrete cognitive complaints. An MRI scan revealed an enlarged ventricular system compatible with NPH. After further liquor dynamic procedures, cerebrospinal fluid (CSF) was analysed with the surprising results of lymphocytic pleocytosis, and signs of increased antibody production. Microbiology revealed chronic neuroborreliosis and the patient was treated with antibiotics accordingly. At the one-year follow-up no symptoms remained and the ventricular system almost normalized.

CONCLUSIONS: We describe the 7th published case of sNPH secondary to chronic Borreliosis in a previous healthy adult. Existing published literature has been reviewed and previous cases showed similarly nearly full clinical recovery. Primary/idiopathic NPH (iNPH) is treated with the surgical intervention of ventriculoperitoneal shunt and can be mistaken for a sNPH. The awareness of rare causes of sNPH like chronic Borreliosis is important as it is easily treated non surgically.