Introduction: Lyme disease is a complex infectious disease affecting multiple organic systems. The most frequent complications are of a dermatological, rheumatological, ophthalmological, cardiac and neurological nature. Among the neurological complications, pseudotumour cerebri is considered to be a rare manifestation of the disease. Hypothyroidism, however, is known to be only infrequently associated to pseudotumour cerebri. Paparone recently reported a case in which Lyme disease and primary hypothyroidism were concurrent, and Becker and Trock described the case of three patients with concurrent thyrotoxicosis and Lyme disease.
Case report: We present the case of a 19 year old female with pseudotumour cerebri and hypothyroidism secondary to autoimmune thyroiditis, which improved after treating her for concomitant Lyme.
Conclusions: We suggest there is a common aetiopathogenic connection between the three processes through autoimmune thyroiditis triggered by Borrelia burgdorferi. Thus, in this patient, the pseudotumour cerebri could be due to either a direct mechanism, triggered by B. burgdorferi, or indirectly, through hypothyroidism secondary to thyroiditis induced by B. burgdorferi, or perhaps to both mechanisms. It might be wise to consider infection by B. burgdorferi in patients with pseudotumour cerebri or thyroiditis coming from areas in which Lyme disease is endemic