A C T A O P H T H A L M O L O G I C A VOL. 5 4 1 9 7 6
Regional Department of Neurosurgery and Neuroradiology, Derbyshire Royal Infirmary, Derby, England (Heads: J . C. Taylor and R. Whitaker)
UNILATERAL PROPTOSIS DUE TO MIDBRAIN TUMOUR A Case Report BY
A. R. CHOUDHURY, J. C. TAYLOR and R. WHITAKER
A case of unilateral proptosis attributed to midbrain tumour is reported. The proptosis disappeared after release of intracranial hypertension. The postulated mechanism of the unilateral proptosis on the left side is a relative increase in orbital venous stasis on that side, consequent upon intracranial hypertension. Key words: midbrain tumour - intracranial hypertension proptosis - exophthalmos.
-
unilateral
Unilateral proptosis in intracranial tumours is caused by a relative increase in orbital content. Tumours about the cavernous sinus may produce ipsilateral proptosis either by their invasion of the orbit (Jackson 1962; Choudhury 1973) or by the production of orbital venous stasis (Dixon 1941; Meadows 1944). In 1948 Gardner reported a case of unilateral exophthalmos which was due to the raised intracranial pressure occurring in a haemangiomatous cyst of the cerebellum; in this case the exophthalmos was caused by a n encephalocele in the orbit through its roof which was absorbed following a previous fracture. Here we report a case of unilateral exophthalmos which was due to raised intracranial pressure occurring on a midbrain tumour and venous stasis in the orbit. Received August 1 7 , 1976. 762
Unilateral Proptosis and Midbrain Tumour
Case Report A 50 year old man was referred to us because of a three month’s history of progressive diplopia and this was associated with dimming of vision in the left eye which was also protruding. Simultaneously he developed increasing weakness of the right arm and leg, and increasing tremor of the right hand. Three years previously in 1971, he was investigated elsewhere for progressive diplopia, right sided hemiparesis and tremor of the right hand. The diplopia disappeared after two months, but the hemiparesis and the tremor improved, but persisted. There was no history of headache or vomiting, nor was there any story of fits. On admission he was normotensive (120/80); there was a right sided spastic hemiparesis, ataxia of the right arm and leg together with static and intention tremor of the right hand. There was obvious left sided proptosis which was non-pulsatile and it could be pressed back into the orbit after some initial resistance. The optic discs were oedematous. The visual fields were normal but the visual acuity was reduced to N 18 in the left eye. Exophthalmometric readings were 16 mm for the right eye and 21 mm for the left eye. The left eye was displaced upwards 2 mm and temporally 4 mm. The diplopia was present on left lateral gaze and on elevation and depression of the globes, and there was marked limitation of vertical conjugate movements of the eyes, with loss of convergence. In view of this combination of signs a clinical diagnosis of intrinsic midbrain neoplasm was made. The ataxia of the right arm and leg, and static and intention tremor of the right hand were thought to be due to the involvement of the right superior cerebellar peduncle. Plain radiographs of the skull and chest were normal and so also was the brain scintiscan. The carotid angiograms (Fig. 1) showed outward displacement of the thalamostriate veins indicating ventricular dilatation. This was confirmed by myodil ventriculogram (Figs. 2 and 3) which also showed a rounded defect in the left side of the floor of the IIIrd ventricle. The origin of the
Fig. I . Bilateral carotid angiogram, showing increased bowing of the thalamostriate veins indicating hydrocephalus.
763
2
3 Figs. 2 and 3. Antero-posterior and lateral views of myodil ventriculogram, showing a mass indenting the left side of the body of the third ventricle with irregularity of the aqueduct.
764
Uniluterul Profitosis and Midbrain Tumour aqueduct was displaced to the left and looked irregular. This suggested a tumour of the midbrain extending up the pedicle into the basal ganglia with possible cyst indenting the IIIrd ventricle. The hydrocephalus was treated by a ventriculo-atrial shunt because of the inaccessible and inoperable nature of the tumour. Post-operatively, there was a dramatic improvement in ocular features. On the day lollowing operation, there was some conjugate vertical eye movement and improvement in the proptosis was noticed. At the time of discharge a week later, there were full conjugate eye movements, the proptosis had disappeared and the optic discs became clear and the visual acuity in the left eye returned to N 8. The diplopia was present cnly at extreme elevation and depression of the globes on left lateral gaze. The exophthalmometric readings were 16 mm for the right eye and 17 mm for the left eye, which was no longer displaced either vertically or horizontally. Although there was little improvement in pyramidal and cerebellar signs, the patient felt subjectively much improved. Follow-up at three months showed no change in neurological signs and at six months showed deterioration in neurological signs. Exophthalmometric readings remained unchanged on both occasions (16 mm for the right eye and 1 7 mm for the left eye).
Discussion This patient presented with unilateral proptosis a n d evidence of a midbrain intrinsic neoplasm as shown by pyramidal signs, ataxia and vertical gaze palsy. Bilateral papilloedema was also present as a definitive sign of raised intracranial pressure. The diplopia might h a v e been caused by limitations of movements of the left eye which were mechanically induced, i. e. attributed to the considerable proptosis of that eye. Interestingly, headache and vomiting were persistently absent. H e had apparently enjoyed a remission in symptoms three years earlier a n d such improvement in intrinsic brain stem neoplasm has been previously reported (Walton 1971). Recent worsening of t h e symptoms was due to the progression of the growth which had produced narrowing of the aqueduct of Sylvius and thus partially obstructed the CSF circulation, with consequent ventricular dilatation and raised intracranial pressure. Return of conjugate vertical eye movements and convergence following release of the intracranial hypertension suggests t h e compression of the midbrain tectum by third ventricular distension (Shallat et al. 1973). T h e r e was n o evidence of intraorbital disease a n d the unilateral proptosis is therefore attributed to the intracranial hypertension. W e suggest the mechanism to be orbital venous stasis from raised intracranial venous pressure consequent on intracranial hypertension. The disappearance of proptosis a n d papilloedenia following release of intracranial hypertension supports the venous hypothesis. T h e temporal a n d upward displacement of the globe of the left eye were presumably a mechanical effect due to bulk of orbital veins lying
765
A . R. Choudhury, J . C . Tuylor and R. Whitaker medially and inferiorly in the orbit. Abolition of such displacements following release of intracranial hypertension supports this view. The unilateral nature of the exopthalmos is very dependent on the variability of the venous drainage of the cavernous sinuses which form the final common pathway for antegrade and retrograde venous flow from and to the orbit respectively. The venous system is remarkably variable, thus the cavernous sinus may fail to develop in one side or the other (Hamby 1966) or the venous drainage of one sinus may predominantly be to the other side (Pool & Potts 1965). We believe that the venous drainage in our case is probably directed towards the left cavernous sinus from the right, thus giving rise to increased orbital venous stasis on the left side and unilateral proptosis.
References Choudhury A. R. (1973) Non-Endocrine Unilateral Proptosis. Trans. ophthal. Soc. U . K . 93, 673-682. Dixon G. J. (1941) Unilateral Exophthalmos (Proptosis). Causation and differential diagnosis. Brain 64, 73-89. Gardner W. J. (1948) Unilateral Exophthalmos due to Cerebellar Tumour and Orbital Defect. J . Neurosirrg. 5, 500-502. Hamby W. B. (1966) Carotid Cavernous Fistula, p. 27. Charles C. Thomas, Springfield, 111. Jackson H. (1962) Orbital Tumours. J . Neurosurg. 19, 551-567. Meadows S. P. (1944) Orbital Tumours. Proc. roy. SOC.Med. 38, 594-600. Pool J. L. & Potts D. G. (1965) Aneurysms and Arteriovenous Anomalies of the Brain, p. 314. Harper & Row, New York. Shallat R. F., Pawl R. P. & Jerva M. J. (1973) Significance of Upward Gaze Palsy (Parinaud's syndrome) in Hydrocephalus due to Shunt Malfunction. J. Neurosurg. 38, 7 1 7-12 1. Walton J. N. (1971) Essentials of Neurology, p. 314, 3rd ed. Pitman Medical and Scientific Publishing Co. Ltd. London.
.4iil/ior's address: Abdur R. Choudhury, F.R.C.S., Department of Neurosurgery, Derbyshire Royal Infirmary, Derby, England.
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Regional Department of Neurosurgery and Neuroradiology, Derbyshire Royal Infirmary, Derby, England (Heads: J . C. Taylor and R. Whitaker)
UNILATERAL PROPTOSIS DUE TO MIDBRAIN TUMOUR A Case Report BY
A. R. CHOUDHURY, J. C. TAYLOR and R. WHITAKER
A case of unilateral proptosis attributed to midbrain tumour is reported. The proptosis disappeared after release of intracranial hypertension. The postulated mechanism of the unilateral proptosis on the left side is a relative increase in orbital venous stasis on that side, consequent upon intracranial hypertension. Key words: midbrain tumour - intracranial hypertension proptosis - exophthalmos.
-
unilateral
Unilateral proptosis in intracranial tumours is caused by a relative increase in orbital content. Tumours about the cavernous sinus may produce ipsilateral proptosis either by their invasion of the orbit (Jackson 1962; Choudhury 1973) or by the production of orbital venous stasis (Dixon 1941; Meadows 1944). In 1948 Gardner reported a case of unilateral exophthalmos which was due to the raised intracranial pressure occurring in a haemangiomatous cyst of the cerebellum; in this case the exophthalmos was caused by a n encephalocele in the orbit through its roof which was absorbed following a previous fracture. Here we report a case of unilateral exophthalmos which was due to raised intracranial pressure occurring on a midbrain tumour and venous stasis in the orbit. Received August 1 7 , 1976. 762
Unilateral Proptosis and Midbrain Tumour
Case Report A 50 year old man was referred to us because of a three month’s history of progressive diplopia and this was associated with dimming of vision in the left eye which was also protruding. Simultaneously he developed increasing weakness of the right arm and leg, and increasing tremor of the right hand. Three years previously in 1971, he was investigated elsewhere for progressive diplopia, right sided hemiparesis and tremor of the right hand. The diplopia disappeared after two months, but the hemiparesis and the tremor improved, but persisted. There was no history of headache or vomiting, nor was there any story of fits. On admission he was normotensive (120/80); there was a right sided spastic hemiparesis, ataxia of the right arm and leg together with static and intention tremor of the right hand. There was obvious left sided proptosis which was non-pulsatile and it could be pressed back into the orbit after some initial resistance. The optic discs were oedematous. The visual fields were normal but the visual acuity was reduced to N 18 in the left eye. Exophthalmometric readings were 16 mm for the right eye and 21 mm for the left eye. The left eye was displaced upwards 2 mm and temporally 4 mm. The diplopia was present on left lateral gaze and on elevation and depression of the globes, and there was marked limitation of vertical conjugate movements of the eyes, with loss of convergence. In view of this combination of signs a clinical diagnosis of intrinsic midbrain neoplasm was made. The ataxia of the right arm and leg, and static and intention tremor of the right hand were thought to be due to the involvement of the right superior cerebellar peduncle. Plain radiographs of the skull and chest were normal and so also was the brain scintiscan. The carotid angiograms (Fig. 1) showed outward displacement of the thalamostriate veins indicating ventricular dilatation. This was confirmed by myodil ventriculogram (Figs. 2 and 3) which also showed a rounded defect in the left side of the floor of the IIIrd ventricle. The origin of the
Fig. I . Bilateral carotid angiogram, showing increased bowing of the thalamostriate veins indicating hydrocephalus.
763
2
3 Figs. 2 and 3. Antero-posterior and lateral views of myodil ventriculogram, showing a mass indenting the left side of the body of the third ventricle with irregularity of the aqueduct.
764
Uniluterul Profitosis and Midbrain Tumour aqueduct was displaced to the left and looked irregular. This suggested a tumour of the midbrain extending up the pedicle into the basal ganglia with possible cyst indenting the IIIrd ventricle. The hydrocephalus was treated by a ventriculo-atrial shunt because of the inaccessible and inoperable nature of the tumour. Post-operatively, there was a dramatic improvement in ocular features. On the day lollowing operation, there was some conjugate vertical eye movement and improvement in the proptosis was noticed. At the time of discharge a week later, there were full conjugate eye movements, the proptosis had disappeared and the optic discs became clear and the visual acuity in the left eye returned to N 8. The diplopia was present cnly at extreme elevation and depression of the globes on left lateral gaze. The exophthalmometric readings were 16 mm for the right eye and 17 mm for the left eye, which was no longer displaced either vertically or horizontally. Although there was little improvement in pyramidal and cerebellar signs, the patient felt subjectively much improved. Follow-up at three months showed no change in neurological signs and at six months showed deterioration in neurological signs. Exophthalmometric readings remained unchanged on both occasions (16 mm for the right eye and 1 7 mm for the left eye).
Discussion This patient presented with unilateral proptosis a n d evidence of a midbrain intrinsic neoplasm as shown by pyramidal signs, ataxia and vertical gaze palsy. Bilateral papilloedema was also present as a definitive sign of raised intracranial pressure. The diplopia might h a v e been caused by limitations of movements of the left eye which were mechanically induced, i. e. attributed to the considerable proptosis of that eye. Interestingly, headache and vomiting were persistently absent. H e had apparently enjoyed a remission in symptoms three years earlier a n d such improvement in intrinsic brain stem neoplasm has been previously reported (Walton 1971). Recent worsening of t h e symptoms was due to the progression of the growth which had produced narrowing of the aqueduct of Sylvius and thus partially obstructed the CSF circulation, with consequent ventricular dilatation and raised intracranial pressure. Return of conjugate vertical eye movements and convergence following release of the intracranial hypertension suggests t h e compression of the midbrain tectum by third ventricular distension (Shallat et al. 1973). T h e r e was n o evidence of intraorbital disease a n d the unilateral proptosis is therefore attributed to the intracranial hypertension. W e suggest the mechanism to be orbital venous stasis from raised intracranial venous pressure consequent on intracranial hypertension. The disappearance of proptosis a n d papilloedenia following release of intracranial hypertension supports the venous hypothesis. T h e temporal a n d upward displacement of the globe of the left eye were presumably a mechanical effect due to bulk of orbital veins lying
765
A . R. Choudhury, J . C . Tuylor and R. Whitaker medially and inferiorly in the orbit. Abolition of such displacements following release of intracranial hypertension supports this view. The unilateral nature of the exopthalmos is very dependent on the variability of the venous drainage of the cavernous sinuses which form the final common pathway for antegrade and retrograde venous flow from and to the orbit respectively. The venous system is remarkably variable, thus the cavernous sinus may fail to develop in one side or the other (Hamby 1966) or the venous drainage of one sinus may predominantly be to the other side (Pool & Potts 1965). We believe that the venous drainage in our case is probably directed towards the left cavernous sinus from the right, thus giving rise to increased orbital venous stasis on the left side and unilateral proptosis.
References Choudhury A. R. (1973) Non-Endocrine Unilateral Proptosis. Trans. ophthal. Soc. U . K . 93, 673-682. Dixon G. J. (1941) Unilateral Exophthalmos (Proptosis). Causation and differential diagnosis. Brain 64, 73-89. Gardner W. J. (1948) Unilateral Exophthalmos due to Cerebellar Tumour and Orbital Defect. J . Neurosirrg. 5, 500-502. Hamby W. B. (1966) Carotid Cavernous Fistula, p. 27. Charles C. Thomas, Springfield, 111. Jackson H. (1962) Orbital Tumours. J . Neurosurg. 19, 551-567. Meadows S. P. (1944) Orbital Tumours. Proc. roy. SOC.Med. 38, 594-600. Pool J. L. & Potts D. G. (1965) Aneurysms and Arteriovenous Anomalies of the Brain, p. 314. Harper & Row, New York. Shallat R. F., Pawl R. P. & Jerva M. J. (1973) Significance of Upward Gaze Palsy (Parinaud's syndrome) in Hydrocephalus due to Shunt Malfunction. J. Neurosurg. 38, 7 1 7-12 1. Walton J. N. (1971) Essentials of Neurology, p. 314, 3rd ed. Pitman Medical and Scientific Publishing Co. Ltd. London.
.4iil/ior's address: Abdur R. Choudhury, F.R.C.S., Department of Neurosurgery, Derbyshire Royal Infirmary, Derby, England.
766
