Meningiomas are typically slow-growing, extra-axial tumors that present with a gradual onset of symptoms related to mass effect. The acute presentation of a patient harboring a meningioma is rare and is almost always associated with hemorrhage [2–13] and sometimes with new onset of seizures. The hemorrhage may be intratumoral, intracerebral, subdural, or subarachnoid [2–13]. It has been proposed that extensive tumor infarction may precipitate tumor-associated hemorrhage and the acute clinical decline of such patients [2]. In this case report, we describe a patient with an olfactory groove meningioma who presented with the signs and symptoms of a herniation syndrome in the absence of tumor-associated hemorrhage. This is a unique presentation for an anterior skull base meningioma

A possible mechanism of deterioration in this patient is the acute development of central tumor necrosis. This could have precipitated an abrupt increase in cerebral edema and intracranial pressure leading to the herniation syndrome observed. On preoperative CT and MR imaging, the presence of significant bifrontal vasogenic edema was evident. Central tumor necrosis has been considered the cause of an acute decline in a previously reported patient with a meningioma who did not, though, progress to herniation [1].

Another plausible mechanism of deterioration includes a seizure event. The degree of mass effect related to cerebral edema could have placed the patient in a critical threshold, where a single seizure (with consequent hypoventilation/hypercarbia) could precipitate catastrophic herniation. This hypothesis raises the importance of prophylactic anti-epileptic medications in patients with meningiomas associated with surrounding edema.

A management nuance highlighted by this case is the timing of surgery once a patient harboring a meningioma acutely deteriorates. In this case, the patient was immediately placed on hyperosmolar therapy and steroids to mitigate the effects of increased intracranial pressure. Fortunately, she had a clinical response to this treatment and the decision was made to continue medical therapy for an additional 36 h prior to surgery. In situations where a clinical response to aggressive medical intervention does not occur and concerns for elevated intracranial pressure persist, urgent surgical decompression should be considered. For patients with meningiomas and extensive parenchymal edema, the paradigm for surgical intervention would be similar to a protocol for intractable intracranial pressure, where urgent intervention is considered when a poor clinical examination is refractory to medical therapy.

Interestingly, although the patient had no light perception on follow-up examination and had MRI evidence of bilateral occipital infarcts, she denied any visual impairment. Anton-Babinski syndrome or Anton’s blindness, where the patient is blind but refuses to acknowledge the condition, is generally the result of trauma or stroke where damage has occurred to the bilateral occipital lobes, resulting in cortical blindness [14]. Although a previous report has associated an anterior skull base meningioma with the syndrome, our case is unique in regard to the acute presentation of a herniation syndrome [15].