Acute interhemispheric subdural hematoma: two case reports and analysis of the literature.
Interhemispheric subdural hematoma (ISH) had been considered extremely rare until identification with imaging studies. Its natural history is still quite unknown in terms of potential origin and course. As a consequence of various controversies, there is still no clearly established treatment, particularly in regard to medical or surgical management. The best decision requires tailoring treatment to the individual patient according to his or her clinical condition. Two patients with acute interhemispheric subdural hematomas are reported, the controversial management of this rare entity is analysed. In reviewing current published cases of interhemispheric subdural hematoma, it seems that the outcome of an individual patient is not related to the therapeutic approach, but to the level of consciousness and the neurological condition on admission. Surgical and medical treatment indications are taken into account for management. A patient with ISH developed an extension of the hematoma to the convexity at 2 weeks of his clinical course, with a decline of his neurological condition. The hematoma was then evacuated through a parietal craniotomy with an uneventful postoperative course. Another case of ISH presented as headache and TIA, with spontaneous clinical improvement at 12 hours and with no decline in the patient's neurological condition. Management was conservative. In both cases the neurological examination was normal after 6 months. As in previously reported cases, the clinical and neurological condition of the patient on admission is crucial for the course of an ISH. Treatment strategies are based on the individual neurological response of each case and the risk-benefit ratio to decide on a medical or surgical approach.