Bilateral post-traumatic hygromas in patient with frontotemporal dementia.

Background: Frontotemporal dementia (FTD) is a highly disabling neurologic disorder characterized by behavioral alterations and movement disorders, involving patients with a mean age of 58 years. We present a unique case of a patient suffering from FTD who developed post traumatic bilateral hygromas.

Case Description: A 52-year-old male patient, with an history of head trauma 3 months before, was admitted to our department for recurrent motor seizures. Anamnesis was positive for FTD with severe frontal syndrome. Brain computed tomography and magnetic resonance imaging (MRI) showed the typical "knife-blade" appearance of the cortical atrophy associated to bilateral hemispheric hygromas exerting mild mass effect. Brain MRI showed the signs of the cortical and "anti-cortical" vein. The two subdural collections were evacuated through two bilateral burr holes and controlled drainage. Despite anti-epileptic drugs therapy, in the early postoperative period, the patient presented further tonic-clonic seizures. The patient showed progressive recovery and was transferred to the neurorehabilitation center. After 6-month follow-up, he completely recovered.

Conclusion: In FTD, severe cortical atrophy leads to space increase between arachnoid and pia mater that could affect the anatomical integrity especially after trauma, with possible development of hygromas. The coexistence of radiological findings of the cortical vein and sign of the "anti-cortical" vein can make difficult an exact differential diagnosis between a primitive hygroma and a Virchow hygroma from resorption of previous blood collection. Surgical treatment may be indicated in selected patients, but it is burdened by higher postoperative risks compared to the general population.