Unruptured aneurysms presenting with mass effect symptoms: response to endosaccular treatment with Guglielmi detachable coils. Part I. Symptoms of cranial nerve dysfunction

sObject. Embolization of intracranial aneurysms by using Guglielmi detachab le coils (GDCs) is proving to be a safe method of protecting aneurysms from rupture. Occasionally, patients with unruptured intracranial aneurysms pre sent with symptoms related to the aneurysm's mass effect on either the brai n parenchyma. or cranial nerves. In the present study, the authors conducte d a retrospective review to evaluate the response to GDC embolization in a series of 19 patients presenting with cranial nerve dysfunction due to mass effect. Methods. Aneurysms were classified by size, shape, wall calcification, and amount of intraluminal thrombus. Patients were classified by duration of sy mptoms prior to GDC treatment (range < 1 month to > 10 years). Clinical ass essment was performed within days of the GDC procedure and at later follow- up appointments (range 1-70 months, mean 24 months). In the immediate post-GDC period, four patients experienced worsening of cr anial nerve deficits. Two of the four patients had transient worsening of v isual acuity, which later improved to better than baseline status. Another patient who had presented with headache and seventh and eighth cranial nerv e deficits from a vertebrobasilar junction aneurysm had improvement in thes e symptoms, but developed a new diplopia. The fourth patient had worsening of her visual acuity, which had not resolved at the I-month follow-up exami nation; this patient later underwent surgical decompression. Conclusions. On late follow-up review, the response was classified as compl ete resolution of symptoms in six patients (32%), improvement in eight pati ents (42%), no significant change in four patients (21%), and symptom worse ning in one patient (5%). Patients with smaller aneurysms and those with sh orter pretreatment duration of symptoms were more likely to experience an i mprovement in their symptoms following GDC treatment, although statistical significance was not reached in this series (p = 0.603 and p = 0.111, respe ctively). The presence of aneurysmal wall calcification (six patients) or i ntraluminal thrombus (12 patients) showed no correlation with the response of mass effect symptoms in these patients.