Clinical Neurology and Neurosurgery 125 (2014) 65–68
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Case report
Cavernous haemangioma of the trochlear nerve: Case report and review of the literature J. Kraschl a , M.C. Spendel a , A. Kiefer b , T. Kau c , S. Grossauer a , G.H. Vince a,∗ a b c
Department of Neurosurgery, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria Department of Pathology, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria Department of Radiology, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria
a r t i c l e
i n f o
Article history: Received 3 April 2014 Received in revised form 22 June 2014 Accepted 14 July 2014 Available online 22 July 2014 Keywords: Cavernoma Cranial nerves Trochlear nerve Nerve anastomosis
1. Introduction
2. Case report
Cerebral cavernonous malformations (CM) are benign lesions, which are classified as vascular harmatomas [8,15]. They can easily be identified with gradient echo T2 or susceptibility weighted MRI sequences and demonstrate a typical berry-like appearance with a reticulated core of high and low signal intensities surrounded by a hypointense rim of deposited haemosiderin [3]. The risk of haemorrhage is considered to be below 1% per year, thus most CMs remain asymptomatic throughout life and are incidental findings on MRI [15]. Their clinical presentation depends on the location of the lesion and the extent of haemorrhage, but tends to be apoplectiform. Seizures, headaches and focal neurological deficits can also occur [2,15,20]. Cranial nerve (CN) involvement is rare, but has been reported for various cranial nerves [4,7,9–11,13,14,16–19,23,24]. Only three cases of trochlear nerve involvement are available in literature [12,21,22].
We report the case of a 70-year-old male who was initially admitted to the Department of Neurology of our institution with a sudden onset of diplopia. The symptoms showed a varied course but became gradually worse over the period of a few weeks. Neurological examination revealed a complete palsy of the right trochlear nerve with vertical double vision, torsional diplopia and positive Bielschowsky head tilt sign. In a characteristic fashion he held his head tilted downwards and to the right side to compensate the weak oblique superior muscle. As the initial MRI was described as being inconspicuous extensive neurological work-up included the examination of CSF and the exclusion of meningitis, demyelinization and ocular myasthenia. A second MRI with high-resolution three-dimensional imaging (3D MRI) including time of flight (TOF) multiple overlapping thin slab acquisition sequences then revealed a small contrast enhancing lesion in the right cerebellopontine angle in the course of the trochlear nerve (Fig. 1a and b). Due to its minute size, however, the lesion could not be further classified radiologically. Surgery was indicated on the grounds of neurological deficits in the presence of a lesion with uncertain histology. The patient had recently recovered from an adeno-carcinoma of the colon and although improbable, was seriously concerned about an association between the newly identified lesion and the previous carcinoma. The tumour was accessed by an infratentorial, retromastoidal and supracerebellar approach along the right cerebellopontine
∗ Corresponding author at: Department of Neurosurgery, Academic Hospital of Klagenfurt, Feschnigstrasse 11, 9020 Klagenfurt, Austria. Tel.: +43 0 463 538 31803. E-mail address: [email protected] (G.H. Vince). http://dx.doi.org/10.1016/j.clineuro.2014.07.020 0303-8467/© 2014 Elsevier B.V. All rights reserved.
66
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68
Fig. 2. Intraoperative view to the right CPA. Tumour (black arrow) and proximal course of the trochlear nerve (white arrow) are visible (Fig. 2a). Resected tumour with typical berry-like aspect of a cavernoma (Fig. 2b).
Fig. 1. T1w MRI axial (Fig. 1a) and coronal (Fig. 1b) images. The minute contrast enhancing lesion is marked with white arrow.
angle with the patient in a semi-sitting position. A small nodulous tumour was found in the middle of trochlear nerve (Fig. 2a). Through the operating microscope it at first did not resemble the typical “mulberry” appearance of a cavernous haemangioma. As the lesion could not be separated or pealed from the nerve and its dignity was initially unclear, the tumour was resected together with a small proximal and distal portion of nerve, which was deemed justifiable in view of the clinically complete trochlear palsy (Fig. 2b). An end-to-end anastomosis was performed and the suture secured using fibrin glue. Histological work-up demonstrated the typical features of a cavernous haemangioma (Fig. 3). The postoperative course was uneventful and the patient’s neurologcial condition was unchanged with right superior oblique palsy consisting of diplopia and image tilting. He was treated with glasses and at 5 months double Vision had nearly fully subsided.
CN involvement and a location within the nerve itself are extremely rare. To date, CMs have been reported for the optic [9,11,23] oculomotor nerve [10,16,17,24], the facial/vestibulocochlear complex [4,14], the hypoglossal nerve [7] and for the trigeminal nerve [13]. Different from those in other cranial nerves, CMs of the optic nerves and system can cause haemorrhage requiring emergency surgery to preserve vision. Only three cases of Cavernomas of the trochlear nerve have been reported in neurosurgical literature so far (Table 1). The trochlear nerve is typically vulnerable, being the longest cranial nerve with the thinnest diameter. In traumatic trochlear nerve injury, the nerve is exposed to torsional and deceleration forces between the mobile incisural segment in the CPA, ambient
Table 1 Available case reports on cavernomas affecting the trochlear nerve. Author
Patient
Treatment
Outcome
Manjila et al. [12]
31 f
Surgical resection
Sindou et al. [21]
65 m
Sürücü et al. [22]
53 m
Surgical resection and sural nerve graft Surgical resection and anastomosis
Persistent nerve palsy Complete recovery of diplopia
3. Discussion CMs can occur throughout the central nervous system, predominantly within in the subcortical brain tissue [2,8].
Complete recovery of diplopia
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68
Fig. 3. Histological sections (HE) with several, mostly congested venous vessels of different width containing flat endothelium with small uniform nuclei. The vascular walls were hypomuscular and extensively hyalinized. Neither calcifications within the walls were detectable nor intraluminal thrombotic changes or signs of recanalization. The angiomatous vessels are arranged in a back-to-back fashion sometimes separated by a delicate fibroglial matrix with sparse lymphocytic infitrates, but without siderophages.
and quadrigeminal cisterns and the fixed tentorial segment [1,12]. All cases of trochlear CM reported and our case likewise presented with sudden onset ipsilateral superior oblique palsy resulting in diplopia, which is differs Cavernomas from other pathologies like schwannomas. Symptoms can from then on gradually progress until trochlear nerve function is completely lost [12,21,22]. Borges and Casselman [3] demonstrate the importance of MRI to differentiate CN lesions and confirm earlier results by Chou et al. [6] who undertook a prospective study of 66 patients with acute isolated ocular mononeuropathies. Extra-axial mass of heterogeneous signal intensity along the lateral aspect of brainstem in the ambient cistern on T1- and T2-weighted MRI narrow the differential diagnosis to schwannoma, cavernous angiomas, hemangioblastomas, or dural-based cavernomas [3,7,12]. In our case, however, the lesion was extremely small and although visible on MRI could not be further differentiated. This goes to show that the size of the lesion need not correlate with the clinical symptoms, which are most likely explained by perineural reaction, nerve infiltration and incidences of bleeding or thrombosis. Surgical resection of intracerebral CM is typically performed along a zone of haemosiderin gliosis between the cavernoma and normal brain tissue. In cranial nerve lesions, however, this is practically not possible due to the intrinsic and circumferential involvement of the nerve [12]. This will make it difficult to salvage the nerve, as it was in the three cases available in literature and the presented one [12,21,22]. Incomplete resection of the cavernoma, on the other hand, will increase the risk of recurrence. As trochlear nerve function was completely lost preoperatively and individual nerve fibres were not clearly definable intraoperatively, a total resection of the lesion was deemed the best treatment option for our case. In literature, various surgical reconstructive procedures have been reported for cases of trochlear nerve injury or severing during lesionectomy. Sekhar et al. [20] reported 6 patients with trochlear nerve injury in which the nerve ends were resutured in 4 cases and nerve grafting was performed in 2 cases. All 4 patients with
67
primary resuturing had a good clinical outcome, and the 2 grafting cases showed a success rate of 50% [20]. Sürücü et al. [22] report complete recovery of trochlear nerve function following gross total resection of the cavernoma and end-to-end anastomosis. Sindou et al. [21] found similar clinical results following cavernoma resection and nerve reconstruction using a graft harvested from the distal part of sural nerve. In one case where anastomosis could not be achieved, the patient still showed trochlear palsy and diplopia 5 months after surgery [12]. In our case we saw complete resolution of diplopia and improvement of trochlear nerve function after end-to-end anastomosis and fibrin glue. This might be attributed to either regeneration of the nerve after surgical repair or to spontaneous adaptation to the condition. Trochlear cavernoma surgery is not reported in the literature enough to allow any further deductions, but some form of immediate nerve anatomosis does appear to increase the chances of later clinical improvement for NIV lesions also [22]. Continuous paralysis of the superior oblique muscle may cause an ipsilateral hypertropia and persistent contralateral head tilt that is too large to correct with prism glasses. Should the patient not improve after surgical nerve repair, this condition is amenable to a range of surgical corrections that include Myectomy and concomitant disinsertion of the inferior oblique (IO) muscle or concomitant IO disinsertion and recession of the superior rectus muscle in the ipsilateral eye [5]. 4. Conclusion CMs located within the cranial nerves are rare lesions that pose a significant threat to CN function. Their radiological characteristics are highly suggestive but, as in our case, often non-diagnostic. Including this case, only four instances of trochlear nerve cavernoma have been reported to date. Therefore, no definitive recommendations regarding treatment can be made, although it appears reasonable that all symptomatic lesions should be treated. Complete surgical excision is the treatment of choice as subtotal resection bears the risk of recurrence. Following resection of the lesion some form of nerve anastomosis is warranted, either by direct resuturing, nerve grafting or fibrin glue adhesion. With regard to diplopia the functional results of surgery are favourable in the long term. Conflict of interest None. References [1] Ammirati M, Musumeci A, Bernardo A, Bricolo A. The microsurgical anatomy of the cisternal segment of the trochlear nerve, as seen through different neurosurgical operative windows. Acta Neurochir 2002;144(12):1323–7. [2] Bertalanffy H, Benes L, Miyazawa T, Alberti O, Siegel AM, Sure U. Cerebral cavernomas in the adult. Review of the literature and analysis of 72 surgically treated patients. Neurosurg Rev 2005;25:1–53. [3] Borges A, Casselman J. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts. Eur Radiol 2007;17(9):2332–44. [4] Bricolo A, De Micheli E, Gambin R, Alessandrini F, Iuzzolino P. Cavernous malformation of the internal auditory canal. A case report. J Neurosurg Sci 1995;39(3):153–8. [5] Caca I, Sahin A, Cingu A, Ari S, Akbas U. Residual symptoms after surgery for unilateral congenital superior oblique palsy. J Pediatr Ophthalmol Strabismus 2012;49(2):103–8. [6] Chou KL, Galetta SL, Liu GT, Volpe NJ, Bennett JL, Asbury AK, et al. Acute ocular motor mononeuropathies: prospective study of the roles of neuroimaging and clinical assessment. J Neurol Sci 2004;219(1–2):35–9. [7] Chow M, Addas B, Sangalang V, Holness R. Cavernous malformation of the hypoglossal nerve: case report and review of the literature. Can J Neurol Sci 2002;29(2):191–4. [8] Clatterbuck RE, Eberhart CG, Crain BJ, Rigamonti D. Ultrastructural and immunocytochemical evidence that an incompetent blood–brain barrier is
68
[9]
[10]
[11]
[12]
[13]
[14] [15] [16]
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68 related to the pathophysiology of cavernous malformations. J Neurol Neurosurg Psychiatry 2001;71:188–92. Hempelmann RG, Mater E, Schröder F, Schön R. Complete resection of a cavernous haemangioma of the optic nerve, the chiasm, and the optic tract. Acta Neurochir 2007;149(7):699–703. Itshayek E, Perez-Sanchez X, Cohen JE, Umansky F, Spektor S. Cavernous hemangioma of the third cranial nerve: case report. Neurosurgery 2007;61(3):E653. Liu JK, Lu Y, Raslan AM, Gultekin SH, Delashaw Jr JB. Cavernous malformations of the optic pathway and hypothalamus: analysis of 65 cases in the literature. Neurosurg Focus 2010;29(3):E17. Manjila S1, Moon K, Weiner MA, Cohen ML, Leigh RJ, Megerian CA, et al. Cavernous malformation of the trochlear nerve: case report and review of the literature on cranial nerve cavernomas. Neurosurgery 2011;69(1):E230–8. Mascarenhas L, Magalha˜es F, Magalha˜es Z, Romão H, Resende M, ResendePereira J, et al. Cavernous malformation of the trigeminal nerve. Neurocirugia (Astur) 2006;17(1):64–7. Miyashita T, Hoshikawa H, Kagawa M, Mori N. A case report of facial nerve hemangioma. Auris Nasus Larynx 2007;34(4):519–22. Moriarity JL, Clatterbuck RE, Rigamonti D. The natural history of cavernous malformations. Neurosurg Clin N Am 1999;10:411–7. Ogilvy CS, Pakzaban P, Lee JM. Oculomotor nerve cavernous angioma in a patient with Roberts syndrome. Surg Neurol 1993;40(1):39–42.
[17] Park DM, Kim DH. Cavernous angioma of the oculomotor nerve. J Korean Neurosurg Soc 2005;38(2):147–50. [18] Ramina K, Ebner FH, Ernemann U, Tatagiba M. Surgery of cavernous hemangioma of the optic nerve: case report and review. J Neurol Surg A Cent Eur Neurosurg 2013;74(4):265–70. [19] Sajadi A1, de Tribolet N. Unusual locations of hemangioblastomas. Case illustration. J Neurosurg 2002;97(3):727. [20] Sekhar LN, Lanzino G, Sen CN, Pomonis S. Reconstruction of the third through sixth cranial nerves during cavernous sinus surgery. J Neurosurg 1992;76(6):935–43. [21] Sindou M, Gilg A, Vighetto A, Jouvet A. Cryptic angioma in the trochlear nerve. Excision of the invaded portion and successful repair with an autologous graft: case report. Neurosurgery 1992;30(2):255–8. [22] Sürücü O, Sure U, Mittelbronn M, Meyermann R, Becker R. Cavernoma of the trochlear nerve. Clin Neurol Neurosurg 2007;109(9):791–3. [23] Sun XY, Yu F. Microsurgical resection of a cavernous angioma that involves the optic pathway using a pterional approach: a case report and literature review. Br J Neurosurg 2012;26(December (6)):882–5, http://dx.doi.org/10. 3109/02688697.2012.685820. [24] Yamada T, Nishio S, Matsunaga M, Fukui M, Takeshita I. Cavernous hemangioma in the oculomotor nerve. A case report. J Nerurol 1986;233:63–4.
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Case report
Cavernous haemangioma of the trochlear nerve: Case report and review of the literature J. Kraschl a , M.C. Spendel a , A. Kiefer b , T. Kau c , S. Grossauer a , G.H. Vince a,∗ a b c
Department of Neurosurgery, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria Department of Pathology, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria Department of Radiology, Academic Hospital of Klagenfurt, 9020 Klagenfurt, Austria
a r t i c l e
i n f o
Article history: Received 3 April 2014 Received in revised form 22 June 2014 Accepted 14 July 2014 Available online 22 July 2014 Keywords: Cavernoma Cranial nerves Trochlear nerve Nerve anastomosis
1. Introduction
2. Case report
Cerebral cavernonous malformations (CM) are benign lesions, which are classified as vascular harmatomas [8,15]. They can easily be identified with gradient echo T2 or susceptibility weighted MRI sequences and demonstrate a typical berry-like appearance with a reticulated core of high and low signal intensities surrounded by a hypointense rim of deposited haemosiderin [3]. The risk of haemorrhage is considered to be below 1% per year, thus most CMs remain asymptomatic throughout life and are incidental findings on MRI [15]. Their clinical presentation depends on the location of the lesion and the extent of haemorrhage, but tends to be apoplectiform. Seizures, headaches and focal neurological deficits can also occur [2,15,20]. Cranial nerve (CN) involvement is rare, but has been reported for various cranial nerves [4,7,9–11,13,14,16–19,23,24]. Only three cases of trochlear nerve involvement are available in literature [12,21,22].
We report the case of a 70-year-old male who was initially admitted to the Department of Neurology of our institution with a sudden onset of diplopia. The symptoms showed a varied course but became gradually worse over the period of a few weeks. Neurological examination revealed a complete palsy of the right trochlear nerve with vertical double vision, torsional diplopia and positive Bielschowsky head tilt sign. In a characteristic fashion he held his head tilted downwards and to the right side to compensate the weak oblique superior muscle. As the initial MRI was described as being inconspicuous extensive neurological work-up included the examination of CSF and the exclusion of meningitis, demyelinization and ocular myasthenia. A second MRI with high-resolution three-dimensional imaging (3D MRI) including time of flight (TOF) multiple overlapping thin slab acquisition sequences then revealed a small contrast enhancing lesion in the right cerebellopontine angle in the course of the trochlear nerve (Fig. 1a and b). Due to its minute size, however, the lesion could not be further classified radiologically. Surgery was indicated on the grounds of neurological deficits in the presence of a lesion with uncertain histology. The patient had recently recovered from an adeno-carcinoma of the colon and although improbable, was seriously concerned about an association between the newly identified lesion and the previous carcinoma. The tumour was accessed by an infratentorial, retromastoidal and supracerebellar approach along the right cerebellopontine
∗ Corresponding author at: Department of Neurosurgery, Academic Hospital of Klagenfurt, Feschnigstrasse 11, 9020 Klagenfurt, Austria. Tel.: +43 0 463 538 31803. E-mail address: [email protected] (G.H. Vince). http://dx.doi.org/10.1016/j.clineuro.2014.07.020 0303-8467/© 2014 Elsevier B.V. All rights reserved.
66
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68
Fig. 2. Intraoperative view to the right CPA. Tumour (black arrow) and proximal course of the trochlear nerve (white arrow) are visible (Fig. 2a). Resected tumour with typical berry-like aspect of a cavernoma (Fig. 2b).
Fig. 1. T1w MRI axial (Fig. 1a) and coronal (Fig. 1b) images. The minute contrast enhancing lesion is marked with white arrow.
angle with the patient in a semi-sitting position. A small nodulous tumour was found in the middle of trochlear nerve (Fig. 2a). Through the operating microscope it at first did not resemble the typical “mulberry” appearance of a cavernous haemangioma. As the lesion could not be separated or pealed from the nerve and its dignity was initially unclear, the tumour was resected together with a small proximal and distal portion of nerve, which was deemed justifiable in view of the clinically complete trochlear palsy (Fig. 2b). An end-to-end anastomosis was performed and the suture secured using fibrin glue. Histological work-up demonstrated the typical features of a cavernous haemangioma (Fig. 3). The postoperative course was uneventful and the patient’s neurologcial condition was unchanged with right superior oblique palsy consisting of diplopia and image tilting. He was treated with glasses and at 5 months double Vision had nearly fully subsided.
CN involvement and a location within the nerve itself are extremely rare. To date, CMs have been reported for the optic [9,11,23] oculomotor nerve [10,16,17,24], the facial/vestibulocochlear complex [4,14], the hypoglossal nerve [7] and for the trigeminal nerve [13]. Different from those in other cranial nerves, CMs of the optic nerves and system can cause haemorrhage requiring emergency surgery to preserve vision. Only three cases of Cavernomas of the trochlear nerve have been reported in neurosurgical literature so far (Table 1). The trochlear nerve is typically vulnerable, being the longest cranial nerve with the thinnest diameter. In traumatic trochlear nerve injury, the nerve is exposed to torsional and deceleration forces between the mobile incisural segment in the CPA, ambient
Table 1 Available case reports on cavernomas affecting the trochlear nerve. Author
Patient
Treatment
Outcome
Manjila et al. [12]
31 f
Surgical resection
Sindou et al. [21]
65 m
Sürücü et al. [22]
53 m
Surgical resection and sural nerve graft Surgical resection and anastomosis
Persistent nerve palsy Complete recovery of diplopia
3. Discussion CMs can occur throughout the central nervous system, predominantly within in the subcortical brain tissue [2,8].
Complete recovery of diplopia
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68
Fig. 3. Histological sections (HE) with several, mostly congested venous vessels of different width containing flat endothelium with small uniform nuclei. The vascular walls were hypomuscular and extensively hyalinized. Neither calcifications within the walls were detectable nor intraluminal thrombotic changes or signs of recanalization. The angiomatous vessels are arranged in a back-to-back fashion sometimes separated by a delicate fibroglial matrix with sparse lymphocytic infitrates, but without siderophages.
and quadrigeminal cisterns and the fixed tentorial segment [1,12]. All cases of trochlear CM reported and our case likewise presented with sudden onset ipsilateral superior oblique palsy resulting in diplopia, which is differs Cavernomas from other pathologies like schwannomas. Symptoms can from then on gradually progress until trochlear nerve function is completely lost [12,21,22]. Borges and Casselman [3] demonstrate the importance of MRI to differentiate CN lesions and confirm earlier results by Chou et al. [6] who undertook a prospective study of 66 patients with acute isolated ocular mononeuropathies. Extra-axial mass of heterogeneous signal intensity along the lateral aspect of brainstem in the ambient cistern on T1- and T2-weighted MRI narrow the differential diagnosis to schwannoma, cavernous angiomas, hemangioblastomas, or dural-based cavernomas [3,7,12]. In our case, however, the lesion was extremely small and although visible on MRI could not be further differentiated. This goes to show that the size of the lesion need not correlate with the clinical symptoms, which are most likely explained by perineural reaction, nerve infiltration and incidences of bleeding or thrombosis. Surgical resection of intracerebral CM is typically performed along a zone of haemosiderin gliosis between the cavernoma and normal brain tissue. In cranial nerve lesions, however, this is practically not possible due to the intrinsic and circumferential involvement of the nerve [12]. This will make it difficult to salvage the nerve, as it was in the three cases available in literature and the presented one [12,21,22]. Incomplete resection of the cavernoma, on the other hand, will increase the risk of recurrence. As trochlear nerve function was completely lost preoperatively and individual nerve fibres were not clearly definable intraoperatively, a total resection of the lesion was deemed the best treatment option for our case. In literature, various surgical reconstructive procedures have been reported for cases of trochlear nerve injury or severing during lesionectomy. Sekhar et al. [20] reported 6 patients with trochlear nerve injury in which the nerve ends were resutured in 4 cases and nerve grafting was performed in 2 cases. All 4 patients with
67
primary resuturing had a good clinical outcome, and the 2 grafting cases showed a success rate of 50% [20]. Sürücü et al. [22] report complete recovery of trochlear nerve function following gross total resection of the cavernoma and end-to-end anastomosis. Sindou et al. [21] found similar clinical results following cavernoma resection and nerve reconstruction using a graft harvested from the distal part of sural nerve. In one case where anastomosis could not be achieved, the patient still showed trochlear palsy and diplopia 5 months after surgery [12]. In our case we saw complete resolution of diplopia and improvement of trochlear nerve function after end-to-end anastomosis and fibrin glue. This might be attributed to either regeneration of the nerve after surgical repair or to spontaneous adaptation to the condition. Trochlear cavernoma surgery is not reported in the literature enough to allow any further deductions, but some form of immediate nerve anatomosis does appear to increase the chances of later clinical improvement for NIV lesions also [22]. Continuous paralysis of the superior oblique muscle may cause an ipsilateral hypertropia and persistent contralateral head tilt that is too large to correct with prism glasses. Should the patient not improve after surgical nerve repair, this condition is amenable to a range of surgical corrections that include Myectomy and concomitant disinsertion of the inferior oblique (IO) muscle or concomitant IO disinsertion and recession of the superior rectus muscle in the ipsilateral eye [5]. 4. Conclusion CMs located within the cranial nerves are rare lesions that pose a significant threat to CN function. Their radiological characteristics are highly suggestive but, as in our case, often non-diagnostic. Including this case, only four instances of trochlear nerve cavernoma have been reported to date. Therefore, no definitive recommendations regarding treatment can be made, although it appears reasonable that all symptomatic lesions should be treated. Complete surgical excision is the treatment of choice as subtotal resection bears the risk of recurrence. Following resection of the lesion some form of nerve anastomosis is warranted, either by direct resuturing, nerve grafting or fibrin glue adhesion. With regard to diplopia the functional results of surgery are favourable in the long term. Conflict of interest None. References [1] Ammirati M, Musumeci A, Bernardo A, Bricolo A. The microsurgical anatomy of the cisternal segment of the trochlear nerve, as seen through different neurosurgical operative windows. Acta Neurochir 2002;144(12):1323–7. [2] Bertalanffy H, Benes L, Miyazawa T, Alberti O, Siegel AM, Sure U. Cerebral cavernomas in the adult. Review of the literature and analysis of 72 surgically treated patients. Neurosurg Rev 2005;25:1–53. [3] Borges A, Casselman J. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts. Eur Radiol 2007;17(9):2332–44. [4] Bricolo A, De Micheli E, Gambin R, Alessandrini F, Iuzzolino P. Cavernous malformation of the internal auditory canal. A case report. J Neurosurg Sci 1995;39(3):153–8. [5] Caca I, Sahin A, Cingu A, Ari S, Akbas U. Residual symptoms after surgery for unilateral congenital superior oblique palsy. J Pediatr Ophthalmol Strabismus 2012;49(2):103–8. [6] Chou KL, Galetta SL, Liu GT, Volpe NJ, Bennett JL, Asbury AK, et al. Acute ocular motor mononeuropathies: prospective study of the roles of neuroimaging and clinical assessment. J Neurol Sci 2004;219(1–2):35–9. [7] Chow M, Addas B, Sangalang V, Holness R. Cavernous malformation of the hypoglossal nerve: case report and review of the literature. Can J Neurol Sci 2002;29(2):191–4. [8] Clatterbuck RE, Eberhart CG, Crain BJ, Rigamonti D. Ultrastructural and immunocytochemical evidence that an incompetent blood–brain barrier is
68
[9]
[10]
[11]
[12]
[13]
[14] [15] [16]
J. Kraschl et al. / Clinical Neurology and Neurosurgery 125 (2014) 65–68 related to the pathophysiology of cavernous malformations. J Neurol Neurosurg Psychiatry 2001;71:188–92. Hempelmann RG, Mater E, Schröder F, Schön R. Complete resection of a cavernous haemangioma of the optic nerve, the chiasm, and the optic tract. Acta Neurochir 2007;149(7):699–703. Itshayek E, Perez-Sanchez X, Cohen JE, Umansky F, Spektor S. Cavernous hemangioma of the third cranial nerve: case report. Neurosurgery 2007;61(3):E653. Liu JK, Lu Y, Raslan AM, Gultekin SH, Delashaw Jr JB. Cavernous malformations of the optic pathway and hypothalamus: analysis of 65 cases in the literature. Neurosurg Focus 2010;29(3):E17. Manjila S1, Moon K, Weiner MA, Cohen ML, Leigh RJ, Megerian CA, et al. Cavernous malformation of the trochlear nerve: case report and review of the literature on cranial nerve cavernomas. Neurosurgery 2011;69(1):E230–8. Mascarenhas L, Magalha˜es F, Magalha˜es Z, Romão H, Resende M, ResendePereira J, et al. Cavernous malformation of the trigeminal nerve. Neurocirugia (Astur) 2006;17(1):64–7. Miyashita T, Hoshikawa H, Kagawa M, Mori N. A case report of facial nerve hemangioma. Auris Nasus Larynx 2007;34(4):519–22. Moriarity JL, Clatterbuck RE, Rigamonti D. The natural history of cavernous malformations. Neurosurg Clin N Am 1999;10:411–7. Ogilvy CS, Pakzaban P, Lee JM. Oculomotor nerve cavernous angioma in a patient with Roberts syndrome. Surg Neurol 1993;40(1):39–42.
[17] Park DM, Kim DH. Cavernous angioma of the oculomotor nerve. J Korean Neurosurg Soc 2005;38(2):147–50. [18] Ramina K, Ebner FH, Ernemann U, Tatagiba M. Surgery of cavernous hemangioma of the optic nerve: case report and review. J Neurol Surg A Cent Eur Neurosurg 2013;74(4):265–70. [19] Sajadi A1, de Tribolet N. Unusual locations of hemangioblastomas. Case illustration. J Neurosurg 2002;97(3):727. [20] Sekhar LN, Lanzino G, Sen CN, Pomonis S. Reconstruction of the third through sixth cranial nerves during cavernous sinus surgery. J Neurosurg 1992;76(6):935–43. [21] Sindou M, Gilg A, Vighetto A, Jouvet A. Cryptic angioma in the trochlear nerve. Excision of the invaded portion and successful repair with an autologous graft: case report. Neurosurgery 1992;30(2):255–8. [22] Sürücü O, Sure U, Mittelbronn M, Meyermann R, Becker R. Cavernoma of the trochlear nerve. Clin Neurol Neurosurg 2007;109(9):791–3. [23] Sun XY, Yu F. Microsurgical resection of a cavernous angioma that involves the optic pathway using a pterional approach: a case report and literature review. Br J Neurosurg 2012;26(December (6)):882–5, http://dx.doi.org/10. 3109/02688697.2012.685820. [24] Yamada T, Nishio S, Matsunaga M, Fukui M, Takeshita I. Cavernous hemangioma in the oculomotor nerve. A case report. J Nerurol 1986;233:63–4.
