Large Posterior Communicating Artery Aneurysm: Initial Presentation with Reproducible Facial Pain Without Cranial Nerve Deficit

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub-arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.

Posterior communicating artery aneurysms causing facial pain: A comprehensive review

Posterior communicating aneurysms are commonly associated with oculomotor nerve palsy. However, trigeminal nerve involvement among these aneurysms is a rare event with no previous analysis. In order to describe the main features of posterior communicating aneurysms causing trigeminal neuralgia (TGN-PComAAs) eight cases (six from the literature plus two more illustrative cases) were included in the present series. All cases were thoroughly studied in order to collect their epidemiological, radiological, clinical, therapeutic, pathogenic, and outcome data. The mean age at diagnosis was 57 years. Gender distribution showed a female predominance (M-to-F ratio 3:5), while side distribution showed a slight left dominance (62%). The aneurysms mean size was 24.7mm (range: 7-40mm). In 7 cases (87.5%) the PComAA was reported to project posteriorly, associated with cavernous sinus extension/compression in two of them and posterior fossa extension in three. No case presented with hemorrhage. Facial pain was the clinical onset in all eight cases, which was reported as an atypical TGN (continuous with exacerbating fits) in 87.5%. Trigger points were absent in all cases but one (87.5%). The most frequent anatomical distribution of the pain was V2 alone (n=3), followed by V1-2 (n=2) and V1-2-3 (n=2). Three different mechanisms for trigeminal neuralgia were observed, namely, cavernous sinus compression (n=4), direct trigeminal root compression (n=3), and oculomotor nerve compression (n=1). Three different treatment options were performed: surgery (n=6), trigeminal thermo-rhizotomy (n=1) and medical management (n=1). According to the Barrow Neurological Institute (BNI) score the pain control after main treatment was I (no pain with no medication) in 7 cases (87.5%). The average modified Rankin scale (mRS) score was 1. In sum, TGN-PComAAs are infrequent lesions characterized by large size and posterior-medial-inferior projection. They mainly cause atypical TGN, most commonly involving the first and second trigeminal distributions (V1-V2). Surgical aneurysmal clipping has been the most frequent treatment option for these aneurysms, providing good neurological results in a vast majority and complete trigeminal pain relief in all cases.