Facial Nerve Schwannoma: The Rare/Great Mimicker of Vestibular Schwannoma/Neuroma.

Schwannomas are benign tumors arising from Schwann cells which are a protective casing of nerves, composing myelin sheath and can develop in any nerve where Schwann cells are present. Most common are vestibulocochlear nerve schwannomas. Facial nerve schwannomas (FNSs) are uncommon tumors involving seventh nerve of which geniculate ganglion involvement is most common. Clinical presentations and the imaging appearances of FNSs are influenced by the topographical anatomy of the facial nerve and vary according to the segments involved. We report a case of 73-year-old man presenting with right side facial weakness of lower motor neuron type involvement. Computed tomography and magnetic resonance imaging are clinching the diagnosis. An early diagnosis is important in containing the disease facilitating early surgical intervention.

Color Doppler Imaging Features of the Lacrimal Sac in Health and Diseased States.

PURPOSE: The objective of this study is to present Color Doppler imaging (CDI) features of the lacrimal sac in normal and diseased states. METHODS: Prospective study was performed on 20 lacrimal sacs of 20 eyes of 10 patients who underwent Color Doppler imaging at a tertiary care Dacryology service over a period of 6 months. All the patients were subjected to Duplex doppler scanning of the lacrimal sacs. Of the 20 lacrimal drainage systems studied, 8 were normal, 8 had primary acquired nasolacrimal duct obstruction (PANDO) and 4 were that of acute dacryocystitis (AcDac). Patient demographics, clinical presentation, duration of the disease and Color Doppler vascular characteristics like peri-sac vascular flow, peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI), arterial spectral waveforms and sac dimensions and wall thickness were analyzed. RESULTS: The vascular flow around the lacrimal sac was increased with higher flow velocities in PANDO as compared to normal and grossly enhanced in AcDac. Flow disturbances were also quite discernible in AcDac. The mean PSV and EDV were 9 & 3.87 cm/sec, 13.07 & 4.63 cm/sec and 18 & 8.5 cm/sec in normal, PANDO and AcDac, respectively. The mean vascular resistivity index increased in patients with PANDO (0.67) and decreased in AcDac (0.53) as compared to the normal (0.57). The arterial spectral waveforms in PANDO and AcDac showed low pulsatility, but the systolic peaks were sharper with more continuous forward flow through diastole in AcDac. This reflects vascular dilatation and reduced resistance to flow in AcDac. CONCLUSION: Characteristic Color Doppler flow parameters can be demonstrated in patients with PANDO and acute dacryocystitis. Color Doppler techniques have the potential to enhance the understanding of lacrimal drainage pathophysiology.