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Anatomy and Embryology of the External and Middle Ear
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
The roof of the epitympanum is the tegmen tympani, a thin bony plate that separates the middle ear space from the middle cranial fossa. Both the petrous and squamous portions of the temporal bone form it; and the petrosquamous suture line, which does not close until adult life, can provide a route of access for infection into the extradural space in children. Veins from the tympanic cavity running to the superior petrosal sinus pass through this suture line. There is a bony crest, known as the cog, which projects from the tegmen tympani caudally to lie anterior to the head of the malleus and can be of variable size. This structure divides the larger posterior epitympanic space from the smaller anterior epitympanic space, where residual cholesteatoma may be left if not formally explored in canal wall-up surgery (Figure 46.6).
Head, neck and vertebral column
Published in David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings, McMinn’s Concise Human Anatomy, 2017
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings
Passing through each cavernous sinus are the internal carotid artery and the abducent nerve. The other two nerves of the extraocular muscles (oculomotor and trochlear nerves) and the ophthalmic and maxillary branches of the trigeminal nerve run in the walls of each cavernous sinus. Other sinuses include the superior petrosal sinus, which runs posteriorly from the cavernous sinus, along the top of the petrous part of the temporal bone, to join the transverse sinus, and the inferior petrosal sinus, which also runs posteriorly from the cavernous sinus, but at a lower level, in the groove between the petrous temporal and occipital bones to pass through the jugular foramen, becoming the highest tributary of the internal jugular vein.
Management of veins during microvascular decompression for idiopathic trigeminal neuralgia
Published in British Journal of Neurosurgery, 2018
Xu Zhao, Shuai Hao, Minqing Wang, Chao Han, Deguang Xing, Chengwei Wang
Only a few studies have examined idiopathic TN caused by venous compression.4,27 However, we believe that veins deserve more attention as the causative factor of TN because offending veins are extremely different from offending arteries, the tactics for treatment of venous type TN are special and the recurrence rate for this type of TN is high.4 It has been reported that solely venous conflicts are responsible for 5-18% of TN cases.1,12,18 The veins that commonly compress the trigeminal nerve are tributaries of the SPV, namely, the transverse pontine vein, the pontotrigeminal vein, the vein of the cerebellopontine fissure and the vein of the middle cerebellar peduncle. The transverse pontine vein, which passes near the nerve to reach the bridging vein entering the superior petrosal sinus, is the most common offending vein.12,18,28 As Lee4 reported, TN attributable to venous compression recurred in approximately 31% of cases after MVD and was likely to recur within 1 year after the initial operation.
Radiologic features of vascular pulsatile tinnitus – suggestion of optimal diagnostic image workup modalities
Published in Acta Oto-Laryngologica, 2018
Ah-Ra Lyu, Sung Jae Park, Dami Kim, Ho Yun Lee, Yong-Ho Park
The demography of patients is described in Table 1. There were more females than males (M:F = 14:35). Tinnitus symptoms were synchronous with the heartbeat in all cases and 38 patients (78%) complained of continuous symptom. Fifteen patients had a history of hypertension. The lesions detected were high jugular bulb (n = 24), jugular bulb dehiscence (n = 6), dural AVF (n = 4), sigmoid sinus diverticulum (n = 3), jugular bulb diverticulum (n = 3), sigmoid sinus dehiscence (n = 2), aberrant carotid artery (n = 2), superior semicircular canal dehiscence (SCD) due to superior petrosal sinus (SPS) (n = 2) ICA narrowing due to atherosclerosis (n = 2) and a rare venous variant presenting as enlarged mastoid emissary vein (n = 1). Almost all (38/41) tinnitus of venous origin showed relief of symptoms with the neck compression test (Table 1).
Percutaneous transorbital embolization of a carotid cavernous fistula
Published in Baylor University Medical Center Proceedings, 2019
Lance J. Lyons, Sarah A. Smith, Orlando Diaz, Humberto Diaz, Aroucha Vickers, Claudia Prospero, Andrew G. Lee
CCFs that drain posteriorly into the inferior or superior petrosal sinuses can spare the ophthalmic venous system and produce a white-eyed shunt. Patients with a posterior draining CCF may be asymptomatic or symptomatic (e.g., headache, facial or eye pain, and diplopia—typically from a sixth nerve palsy). However, anterior drainage involving the ophthalmic veins may cause ophthalmic venous hypertension and resultant orbital congestion (“red-eyed shunt”). In the case above, onset of symptoms paralleled angiographic evidence of flow reversal from partial thrombosis. Treatment was initiated after the development of an acute transition from white-eyed to red-eyed shunt, markedly elevated intraocular pressure, and acute visual loss from presumed posterior ischemic optic neuropathy.