PMC9774482_01
The patient had been using an eye patch to prevent episodes of recurrent trigeminal pain triggered by bright light, as illustrated in the picture above. Area of recurred pain are coloured in red (), corresponding to the ophthalmic and maxillary branches of the trigeminal nerve; abbreviations: V1, ophthalmic branch of the trigeminal nerve; V2, maxillary branch of the trigeminal nerve; V3, mandibular branch of the trigeminal nerve.
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F1
Subsequently, she covered her left eye with a patch to avoid triggering the pain episodes (Figure 1).
Axial computed tomography (CT) scan without contrast showing hyperdense lesion (A) and magnetic resonance imaging (MRI) T1 with gadolinium contrast (B) showing T1 low to medium intensity, contrast-enhancing lesion compressing the superolateral portion of left trigeminal nerve root entry zone (CN.V), suggesting Teflon granuloma (TG). Left superior (C), left lateral (D), left anterolateral (E), and posterolateral (F) view of the 3D reconstruction using 3D Slicer  software showing the relation between Teflon granuloma, trigeminal nerve, superior cerebellar artery, superior petrosal vein, and the remaining brainstem parenchyma. Trigeminal nerve is coloured as yellow (); artery as red (); vein as blue (); and brainstem parenchyma as green ().
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F2
Magnetic resonance imaging (MRI) and pre-operative 3D reconstruction suggested a Teflon granuloma (TG) compressing the left trigeminal nerve root (Figure 2).
(A) craniotomy was conducted using the left retrosigmoid approach and the same skin incision as for the initial surgery. (B) Intraoperative findings showed a non-neurovascular origin compression (Teflon granuloma) of the trigeminal nerve root entry zone rostro-lateral portion. The granuloma was tightly adhered to the mildly atrophic trigeminal nerve, with no marked angulation. Local thickening of the arachnoid membrane was also present, adherent to the nerve. (C) The granuloma was debulked, and the remaining granulation was transposed by dissecting it free from the nerve root. Surgicel  was used to avoid direct contact between the remaining TG and surrounding tissue. (D) Partial internal rhizotomy was conducted following the MVD; abbreviations: CN. V, trigeminal nerve; TG, Teflon granuloma.
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F3
The second MVD was performed through the same skin incision and craniotomy (Figure 3).