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Ocular signs due to an oculomotor intranuclear lesion: palsy of adduction and contralateral eye elevation
Ocular signs due to an oculomotor intranuclear lesion: palsy of adduction and contralateral eye elevation N. Saeki MD, A. Yamaura MD Department of Neurological Surgery, Chiba University School of Medicine, Chiba, Japan
Summary Reports on ocular signs of discrete oculomotor nuclear lesions have been rare. This is a case report of a patient with the sudden onset of limited adduction on the left side and bilateral elevation palsy, more pronounced on the right side. The symptoms lasted for 3 days. Neuroimaging study did not reveal a responsible lesion. The patient was diagnosed as having a lacunar infarct. It is neuroanatomically established that the oculomotor subnucleus to the superior rectus muscle primarily cross-innervates the muscle. The palsy of adduction and contralateral supraduction is most plausibly explained by a partial oculomotor nuclear lesion. This patient demonstrated the intranuclear close arrangement of the nerves for the superior and medial rectus muscles. This case reminds us of the clinical importance of basic anatomy based neurological examinations in this computer orientated, high tech era. © 2000 Harcourt Publishers Ltd
CT scan demonstrated no abnormality in the brain stem. The patient was diagnosed as having a lacunar infarct. The ocular signs gradually improved over the next day and had resolved 3 days later. T1-weighted magnetic resonance images (MRI) with and without gadolinium enhancement and T2-weighted images 1 week later did not display a responsible lesion (Fig. 2). During the next 5 year follow up period, the patient developed a left hemiparesis and dysarthria due to three episodes of cerebral infarction, confirmed on CT scans. Therefore, the first ocular disturbance was attributed to ischaemia of the midbrain. DISCUSSION The patient demonstrated impaired adduction of the left eye, and bilateral elevation palsy, more remarkable on the right side. No responsible lesion was demonstrated on either CT scan or MRI. The combination of ocular impairments was most plausibly explained by an oculomotor intranuclear lesion. The fibres from the superior rectus subnucleus cross the midline and pass through the contralateral subnucleus. Thus, the subnucleus for the superior rectus functions on either side of the brain stem & give rise to fibres that innervate the contralateral (and to a lesser extent, the ipsilateral) superior rectus muscle.5 The lesions that affect this region, while causing ipsilateral deficiencies of superior rectus, thus also produce limitation of elevation of the contralateral eye from impairment of superior rectus function. Such patients have bilateral limitation of upward gaze, often worse on the contralateral side.2,5 A small left subnuclear lesion of the superior rectus and medial
Journal of Clinical Neuroscience (2000) 7 (2), 153–154 © 2000 Harcourt Publishers Ltd DOI: 10.1054/ jocn.1998.0172, available online at http://www.idealibrary.com on
Received 21 October 1998 Accepted 23 December 1998 Correspondence to: Naokatsu Saeki, Department of Neurological Surgery, Chiba University School of Medicine, 1–8–1 Inohana, Chuoh-ku, Chiba-shi, Chiba, Japan 260–8670. Tel.: +81 43 222 7171; ext. 5404; Fax: +81 43 225 0573.
INTRODUCTION Reports on discrete oculomotor nuclear lesions are rare.1–7 This is a case report of an impairment of extraocular movements due to an oculomotor nuclear lesion with photographic demonstration of ocular motions.
Fig. 1 Eye signs at the acute stage. Exotropia in the neutral position and adduction palsy on the left eye were noted. Impaired supraduction of both eyes, more pronounced on the right was demonstrated. Note the higher corneal point of light on the right side in upward gaze.
CASE PRESENTATION A 39 year old man, who had a history of mild and untreated hypertension for 5 years, complained of a sudden onset of double vision. Since the symptoms did not subside by the next morning, he visited our outpatient clinic. The blood pressure was 158/98 and pulse rate 86/min. Blood tests showed elevated cholesterol (265 mg/ml) and triglyceride (196 mg/100 ml) but were otherwise normal, including euglycaemia. Neurologically, the abnormal extraocular movements were the cardinal signs. An exotropic position was noted on the left side. On right lateral gaze, adduction of left eye was impaired. No associated nystagmus was noted in the right eye. Upward gaze was limited bilaterally, more pronounced on the right. Bell’s phenomenon was not observed. He could not converge. The other exraocular movements were normal. There was no ptosis or anisocoria (Fig. 1).
Fig. 2 Eye signs 3 days later. No EOM limitation was noted.
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154 Saeki and Yamaura/Vadlamudi et al.
rectus muscles could cause the ocular abnormalities in our case. We need to differentiate the oculomotor intranuclear lesion in our case from the other brain stem lesions. A left medial longitudinal fasciculus (MLF) lesion may mimic the impairment of horizontal gaze palsy in this patient. However, there was a lack of associated nystagmus of the right eye. In addition an upward gaze palsy would not occur with a pure MLF lesion. An upward gaze palsy could be attributable to a supranuclear lesion, such as the rostral interstitial nucleus of the MLF or posterior commissure, which, however, would not cause a horizontal gaze palsy. No motion of eye elevation with Bell’s phenomenon is likely to exclude a supranuclear lesion. The intranuclear topography of the human oculomotor nucleus has been based on animal experiments and reports of several human patients.1–9 The rostro-caudal order of oculomotor nuclear arrangement is the unpaired visceral nucleus for the pupillary sphincter, paired somatic nuclei for muscles of extraocular motion and unpaired central caudal nucleus for levator palpebrae.9 The rostrocaudal diameter is 10 mm.10,11 In our case, the lesion was restricted to a small part of a left somatic nucleus, approximating a few mm or less. The small size of the presumed ischaemic lesion which produced deficits lasting only 3 days were the reasons why we failed to radiologically identify the responsible lesion in this patient. There have been reports demonstrating decussation of the muscle innervation in human patients, using CT scan or MRI; their lesions were exceptionally large and severe and produced long lasting brain stem signs which were detectable neuroradiologically. This case presents the evidence of cross-innervation of the superior rectus muscle in a human patient, even though no radiological support was obtained. Neurologically, a small lesion of the left somatic subnucleus at the dorsal midbrain could cause this rare combination of impaired ocular motions. This also suggests the intra-subnuclear arrangement of extra-ocular muscles. The impaired supraduction and adduction implied close arrangement of the superior rectus and
medial rectus in the human oculomotor subnucleus, which is compatible with a scheme in the Rhesus monkey9 and a scheme proposed by Ksiazek et al.12 This patient reminds us of the importance of basic anatomy based neurological examination in this neuroimaging orientated high technology era.
REFERENCES 1. Bogousslavsky J, Regli F. Intra-axial syndromes of the oculomotor nerve from midbrain infarct. Rev Nuerol (Paris) 1984; 140: 263–270. 2. Bogousslavsky J, Maeder P, Regli F, Meuli R. Pure midbrain infarction: clinical syndrome, MRI, and etiologic patterns. Neurology 1994; 44: 2032–2040. 3. Dehaene I, Marchau M, Vanhooren GT. Nuclear oculomotor nerve paralysis. Neuro-ophthalmology 1987; 7: 219–222. 4. Kaji R, Akiguchi I, Kameyama M, Toyoshima M. Oculomotor nerve nucleus syndrome; Crossed innervation of the superior rectus muscle. Clin Neurol (Tokyo) 1983; 23: 242–246. 5. Miller NR. Walsh and Hoyt’s Clinical Neuroophthalmology, Vol. 2, 4th edn. Baltimore: Williams and Wilkins, 1985; 657–660. 6. Pierrot-Deseilligny C, Schaison M, Bousser MG, Brunet P. Oculomotor nerve nucleus syndrome; report of two cases. Rev Neurol (Paris) 1981; 137: 217–222. 7. Pratt DV, Orengo-Nania S, Horowitz BA, Oram O. Magnetic resonance imaging findings in a patient with nuclear oculomotor palsy. Arch Ophthalmol 1995; 113: 141–142. 8. Bienfang DC. Crossing axons in the third nerve nucleus. Investigative Ophthalmology 1975; 14: 927–931. 9. Warwick R. Representation of extra-ocular muscles in oculomotor nuclei of monkey. J Comp Neurol 1953; 98: 449–495. 10. Marinkovic S, Marinkovic Z, Filipovic B. The oculomotor nuclear complex in humans. Microanatomy and clinical significance. Neuroligia 1989; 38: 135–146. 11. Nadeau SE, Trobe JD. Pupil sparing in oculomotor nerve palsy. A brief review. Ann Neurol 1983; 13: 143–148. 12. Ksiazek SM, Slamovits TL, Rosen CE, Burde RM, Parisi F. Fascicular arrangement in partial oculomotor paresis. Am J Ophthalmol 1994; 118: 97–103.
Journal of Clinical Neuroscience (2000) 7 (2), 154–156 © 2000 Harcourt Publishers Ltd
RasmussenÕs syndrome in a 54 year old female: more support for an adult variant
DOI: 10.1054/ jocn.1998.0173, available online at http://www.idealibrary.com on
Keywords: Rasmussen’s syndrome, chronic encephalitis, magnetic resonance imaging Received 30 November 1998 Accepted 23 December 1998 Correspondence to: Richard Boyle
Lata Vadlamudi, Clare J. Galton, Susanne J. Jeavons, Anthony E.G. Tannenberg, Richard S. Boyle Department of Neurosciences, Princess Alexandra Hospital, Ipswich Road, Woolloongabba QLD 4102, Australia
Summary Rasmussen’s syndrome, a syndrome of chronic focal encephalitis, is usually considered to be a disease of childhood.Typical features include intractable focal seizures and progressive unilateral neurological deficits with radiological evidence of focal cortical atrophy. This report documents the case of the oldest patient yet described in the literature with Rasmussen’s syndrome. Magnetic resonance imaging revealed gadolinium enhancing tissue, not previously described in this condition. © 2000 Harcourt Publishers Ltd
Journal of Clinical Neuroscience (2000) 7(2)
INTRODUCTION Rasmussen’s syndrome was initially described in three children with focal seizures secondary to chronic localised encephalitis.1 Over 100 childhood cases have since been reported with the clinical syndrome involving intractable partial seizures, often with epilepsia partialis continua, progressive neurological deterioration with hemiparesis (and dysphasia if the dominant hemisphere is involved)2,3 and radiological evidence of unilateral progressive cerebral atrophy.4 We present a patient who developed the typical features of Rasmussen’s syndrome presenting in the sixth decade of life.
© 2000 Harcourt Publishers Ltd
Summary Reports on ocular signs of discrete oculomotor nuclear lesions have been rare. This is a case report of a patient with the sudden onset of limited adduction on the left side and bilateral elevation palsy, more pronounced on the right side. The symptoms lasted for 3 days. Neuroimaging study did not reveal a responsible lesion. The patient was diagnosed as having a lacunar infarct. It is neuroanatomically established that the oculomotor subnucleus to the superior rectus muscle primarily cross-innervates the muscle. The palsy of adduction and contralateral supraduction is most plausibly explained by a partial oculomotor nuclear lesion. This patient demonstrated the intranuclear close arrangement of the nerves for the superior and medial rectus muscles. This case reminds us of the clinical importance of basic anatomy based neurological examinations in this computer orientated, high tech era. © 2000 Harcourt Publishers Ltd
CT scan demonstrated no abnormality in the brain stem. The patient was diagnosed as having a lacunar infarct. The ocular signs gradually improved over the next day and had resolved 3 days later. T1-weighted magnetic resonance images (MRI) with and without gadolinium enhancement and T2-weighted images 1 week later did not display a responsible lesion (Fig. 2). During the next 5 year follow up period, the patient developed a left hemiparesis and dysarthria due to three episodes of cerebral infarction, confirmed on CT scans. Therefore, the first ocular disturbance was attributed to ischaemia of the midbrain. DISCUSSION The patient demonstrated impaired adduction of the left eye, and bilateral elevation palsy, more remarkable on the right side. No responsible lesion was demonstrated on either CT scan or MRI. The combination of ocular impairments was most plausibly explained by an oculomotor intranuclear lesion. The fibres from the superior rectus subnucleus cross the midline and pass through the contralateral subnucleus. Thus, the subnucleus for the superior rectus functions on either side of the brain stem & give rise to fibres that innervate the contralateral (and to a lesser extent, the ipsilateral) superior rectus muscle.5 The lesions that affect this region, while causing ipsilateral deficiencies of superior rectus, thus also produce limitation of elevation of the contralateral eye from impairment of superior rectus function. Such patients have bilateral limitation of upward gaze, often worse on the contralateral side.2,5 A small left subnuclear lesion of the superior rectus and medial
Journal of Clinical Neuroscience (2000) 7 (2), 153–154 © 2000 Harcourt Publishers Ltd DOI: 10.1054/ jocn.1998.0172, available online at http://www.idealibrary.com on
Received 21 October 1998 Accepted 23 December 1998 Correspondence to: Naokatsu Saeki, Department of Neurological Surgery, Chiba University School of Medicine, 1–8–1 Inohana, Chuoh-ku, Chiba-shi, Chiba, Japan 260–8670. Tel.: +81 43 222 7171; ext. 5404; Fax: +81 43 225 0573.
INTRODUCTION Reports on discrete oculomotor nuclear lesions are rare.1–7 This is a case report of an impairment of extraocular movements due to an oculomotor nuclear lesion with photographic demonstration of ocular motions.
Fig. 1 Eye signs at the acute stage. Exotropia in the neutral position and adduction palsy on the left eye were noted. Impaired supraduction of both eyes, more pronounced on the right was demonstrated. Note the higher corneal point of light on the right side in upward gaze.
CASE PRESENTATION A 39 year old man, who had a history of mild and untreated hypertension for 5 years, complained of a sudden onset of double vision. Since the symptoms did not subside by the next morning, he visited our outpatient clinic. The blood pressure was 158/98 and pulse rate 86/min. Blood tests showed elevated cholesterol (265 mg/ml) and triglyceride (196 mg/100 ml) but were otherwise normal, including euglycaemia. Neurologically, the abnormal extraocular movements were the cardinal signs. An exotropic position was noted on the left side. On right lateral gaze, adduction of left eye was impaired. No associated nystagmus was noted in the right eye. Upward gaze was limited bilaterally, more pronounced on the right. Bell’s phenomenon was not observed. He could not converge. The other exraocular movements were normal. There was no ptosis or anisocoria (Fig. 1).
Fig. 2 Eye signs 3 days later. No EOM limitation was noted.
153
154 Saeki and Yamaura/Vadlamudi et al.
rectus muscles could cause the ocular abnormalities in our case. We need to differentiate the oculomotor intranuclear lesion in our case from the other brain stem lesions. A left medial longitudinal fasciculus (MLF) lesion may mimic the impairment of horizontal gaze palsy in this patient. However, there was a lack of associated nystagmus of the right eye. In addition an upward gaze palsy would not occur with a pure MLF lesion. An upward gaze palsy could be attributable to a supranuclear lesion, such as the rostral interstitial nucleus of the MLF or posterior commissure, which, however, would not cause a horizontal gaze palsy. No motion of eye elevation with Bell’s phenomenon is likely to exclude a supranuclear lesion. The intranuclear topography of the human oculomotor nucleus has been based on animal experiments and reports of several human patients.1–9 The rostro-caudal order of oculomotor nuclear arrangement is the unpaired visceral nucleus for the pupillary sphincter, paired somatic nuclei for muscles of extraocular motion and unpaired central caudal nucleus for levator palpebrae.9 The rostrocaudal diameter is 10 mm.10,11 In our case, the lesion was restricted to a small part of a left somatic nucleus, approximating a few mm or less. The small size of the presumed ischaemic lesion which produced deficits lasting only 3 days were the reasons why we failed to radiologically identify the responsible lesion in this patient. There have been reports demonstrating decussation of the muscle innervation in human patients, using CT scan or MRI; their lesions were exceptionally large and severe and produced long lasting brain stem signs which were detectable neuroradiologically. This case presents the evidence of cross-innervation of the superior rectus muscle in a human patient, even though no radiological support was obtained. Neurologically, a small lesion of the left somatic subnucleus at the dorsal midbrain could cause this rare combination of impaired ocular motions. This also suggests the intra-subnuclear arrangement of extra-ocular muscles. The impaired supraduction and adduction implied close arrangement of the superior rectus and
medial rectus in the human oculomotor subnucleus, which is compatible with a scheme in the Rhesus monkey9 and a scheme proposed by Ksiazek et al.12 This patient reminds us of the importance of basic anatomy based neurological examination in this neuroimaging orientated high technology era.
REFERENCES 1. Bogousslavsky J, Regli F. Intra-axial syndromes of the oculomotor nerve from midbrain infarct. Rev Nuerol (Paris) 1984; 140: 263–270. 2. Bogousslavsky J, Maeder P, Regli F, Meuli R. Pure midbrain infarction: clinical syndrome, MRI, and etiologic patterns. Neurology 1994; 44: 2032–2040. 3. Dehaene I, Marchau M, Vanhooren GT. Nuclear oculomotor nerve paralysis. Neuro-ophthalmology 1987; 7: 219–222. 4. Kaji R, Akiguchi I, Kameyama M, Toyoshima M. Oculomotor nerve nucleus syndrome; Crossed innervation of the superior rectus muscle. Clin Neurol (Tokyo) 1983; 23: 242–246. 5. Miller NR. Walsh and Hoyt’s Clinical Neuroophthalmology, Vol. 2, 4th edn. Baltimore: Williams and Wilkins, 1985; 657–660. 6. Pierrot-Deseilligny C, Schaison M, Bousser MG, Brunet P. Oculomotor nerve nucleus syndrome; report of two cases. Rev Neurol (Paris) 1981; 137: 217–222. 7. Pratt DV, Orengo-Nania S, Horowitz BA, Oram O. Magnetic resonance imaging findings in a patient with nuclear oculomotor palsy. Arch Ophthalmol 1995; 113: 141–142. 8. Bienfang DC. Crossing axons in the third nerve nucleus. Investigative Ophthalmology 1975; 14: 927–931. 9. Warwick R. Representation of extra-ocular muscles in oculomotor nuclei of monkey. J Comp Neurol 1953; 98: 449–495. 10. Marinkovic S, Marinkovic Z, Filipovic B. The oculomotor nuclear complex in humans. Microanatomy and clinical significance. Neuroligia 1989; 38: 135–146. 11. Nadeau SE, Trobe JD. Pupil sparing in oculomotor nerve palsy. A brief review. Ann Neurol 1983; 13: 143–148. 12. Ksiazek SM, Slamovits TL, Rosen CE, Burde RM, Parisi F. Fascicular arrangement in partial oculomotor paresis. Am J Ophthalmol 1994; 118: 97–103.
Journal of Clinical Neuroscience (2000) 7 (2), 154–156 © 2000 Harcourt Publishers Ltd
RasmussenÕs syndrome in a 54 year old female: more support for an adult variant
DOI: 10.1054/ jocn.1998.0173, available online at http://www.idealibrary.com on
Keywords: Rasmussen’s syndrome, chronic encephalitis, magnetic resonance imaging Received 30 November 1998 Accepted 23 December 1998 Correspondence to: Richard Boyle
Lata Vadlamudi, Clare J. Galton, Susanne J. Jeavons, Anthony E.G. Tannenberg, Richard S. Boyle Department of Neurosciences, Princess Alexandra Hospital, Ipswich Road, Woolloongabba QLD 4102, Australia
Summary Rasmussen’s syndrome, a syndrome of chronic focal encephalitis, is usually considered to be a disease of childhood.Typical features include intractable focal seizures and progressive unilateral neurological deficits with radiological evidence of focal cortical atrophy. This report documents the case of the oldest patient yet described in the literature with Rasmussen’s syndrome. Magnetic resonance imaging revealed gadolinium enhancing tissue, not previously described in this condition. © 2000 Harcourt Publishers Ltd
Journal of Clinical Neuroscience (2000) 7(2)
INTRODUCTION Rasmussen’s syndrome was initially described in three children with focal seizures secondary to chronic localised encephalitis.1 Over 100 childhood cases have since been reported with the clinical syndrome involving intractable partial seizures, often with epilepsia partialis continua, progressive neurological deterioration with hemiparesis (and dysphasia if the dominant hemisphere is involved)2,3 and radiological evidence of unilateral progressive cerebral atrophy.4 We present a patient who developed the typical features of Rasmussen’s syndrome presenting in the sixth decade of life.
© 2000 Harcourt Publishers Ltd