Unilateral midbrain infarction causing upward and downward gaze palsy.

We report on a 47-year-old-woman who developed sudden complete loss of vertical saccades, smooth pursuit, and vestibular eye movements bilaterally. MRI revealed a unilateral midbrain infarct involving the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the interstitial nucleus of Cajal (INC) and spared the posterior commissure (PC). The lesion is presumed to have interrupted the pathways involved in vertical gaze just before they decussate, inducing an anatomically unilateral but functionally bilateral lesion. Previous reports of bidirectional vertical gaze palsy have shown lesions involving the PC or both riMLFs. This case is the first to show that a unilateral lesion of the riMLF and the INC that spares the PC may cause complete bidirectional vertical gaze palsy.     

Monocular elevation paresis and contralateral downgaze paresis from unilateral mesodiencephalic infarction.

A 26 year old woman presented with monocular elevation paresis of the right eye, contralateral paresis of downward gaze, and subtle bilateral ptosis. Magnetic resonance imaging disclosed a unilateral embolic infarction restricted to the mesodiencephalic junction involving the left paramedian thalamus. Preserved vertical oculocephalic movements and intact Bell's phenomenon suggested a supranuclear lesion. This rare "crossed vertical gaze paresis" results from a lesion near the oculomotor nucleus affecting ipsilateral downward gaze and contralateral upward gaze fibres, originating in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF).     

A case presenting vertical one-and-a-half syndrome and seesaw nystagmus due to thalamomesencephalic infarction]

A 58-year-old woman presented, conjugate upgaze palsy and monocular paresis of downward gaze in the ipsilateral eye (vertical one-and-a-half syndrome; VOHS) as well as seesaw nystagmus (SSN). Vertical oculocephalic response and conjugate horizontal gaze were preserved. Magnetic resonance imaging revealed a right thalamo-mesencephalic infarction including the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the interstitial nucleus of Cajal. On the 22nd hospital day SSN was disappeared, and then on the 32nd day VOHS was improved. The lesions of VOHS may have affected the efferent tracts of riMLF and the descending fibres to the ipsilateral subnucleus of the inferior rectus and contralateral subnucleus of the superior oblique. Furthermore, it was assumed that SSN was caused simultaneously by a lesion in the interstitial nucleus of Cajal existing in the adjacent area of riMLF.     

Vertical gaze palsy and selective unilateral infarction of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF).

We report a clinico-pathological correlation study in a patient with basilar artery thrombosis, who developed tetraplegia and combined up- and downgaze palsy involving voluntary saccades and visually-guided movements, but sparing the oculocephalic responses. At necropsy, apart from bilateral infarction in the basis pontis, there was a single unilateral infarct selectively destroying the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) on the right. The posterior commissure and its nucleus, the nucleus of Cajal, the nucleus of Darkschewitsch and the pontine tegmentum were spared. We suggest that the unilateral riMLF lesion may have disrupted bilateral upgaze excitatory and inhibitory inputs and unilateral downgaze excitatory inputs. The functional anatomy of inhibitory and excitatory vertical gaze circuitry, which remains speculative, may explain why a unilateral lesion of the upper midbrain tegmentum may be sufficient to generate an upgaze palsy or a combined up- and downgaze palsy, while an isolated downgaze palsy requires bilateral lesions.     

Claude's syndrome associated with supranuclear horizontal gaze palsy caused by dorsomedial midbrain infarction

Claude's syndrome caused by dorsal midbrain lesion is characterized by ipsilateral third nerve palsy and contralateral ataxia. To date, reports in the literature concerning Claude's syndrome associated with the midbrain paresis of horizontal gaze are rare. A 62-year-old man suddenly developed left third cranial nerve palsy, right lateral gaze palsy, and right ataxia. Intact Bell's phenomenon and preserved right horizontal oculocephalic reflex suggested the lateral gaze palsy in the right eye was supranuclear in nature. Magnetic resonance imaging (MRI) revealed an infarction in the left dorsomedial midbrain. Although the red nucleus has often been suggested as the lesion site responsible for Claude's syndrome, a lesion of the superior cerebellar peduncle just below and medial to the red nucleus could be responsible for this syndrome. This case demonstrates neurological heterogeneity of midbrain infarction.     

Isolated nuclear oculomotor nerve palsy due to mesencephalic infarction

A patient with unilateral nuclear oculomotor palsy due to midbrain infarction is described. A 46-year-old man was admitted because of difficulty in opening right eye and double vision noticed when he awoke in that morning. On admission, neurological examination revealed total right oculomotor palsy with slight impairment of left upward gaze. There were no other neurologic abnormalities at all. Brain CT and cerebral angiograms were also normal. Magnetic resonance imaging (MRI) performed on the ninth day, however, demonstrated high signal intensity in the right tegmentum of the mesencephalon on T2-weighted images, which was shown more clearly after the administration of Gadolinium-DPTA. He was diagnosed as nuclear third nerve palsy caused by midbrain infarction. The majority of isolated oculomotor nerve palsy has been reported to be caused by extraaxial lesion. When the oculomotor palsy is caused by intraaxial ischemic lesion, it is usually accompanied by other brain stem signs, because abundant nuclei and fibers are present adjacent to the oculomotor nucleus and nerve in the mesencephalon. The present case clarified that such a small infarct disclosed only by MRI can cause isolated oculomotor nerve palsy. It is emphasized that the intraaxial ischemic lesion should be ruled out by using the sophisticated diagnostic aid before making diagnosis of peripheral lesion. This is the first report of the isolated third nerve palsy resulting from mesencephalic ischemic lesion in the Japanese.     

Bilateral medial medullary infarction presenting as vertical gaze palsy]

A 79-year old man noticed paresthesia in all 4 limbs, quadriplegia and dysarthria, and then developed respiratory arrest requiring mechanical ventilation. After level of consciousness was improved, vertical gaze palsy, left hemifacial palsy (central type) and quadriplegia were noted. Brain magnetic resonance imaging (MRI) on day 9 revealed bilateral upper medial medullary infarction. In general, the vertical gaze center is thought to be present in the midbrain, including the rostral interstitial nucleus of the medial longitudinal fasciculus, posterior commissure and interstitial nucleus of Cajal. Few reports have described vertical gaze palsy due to medullary lesions. The upper medial medullary lesions, particularly the paramedian tract in the medulla, may have been responsible for vertical gaze palsy in this patient.     

Palsy of upward and downward saccadic, pursuit, and vestibular movements with a unilateral midbrain lesion: pathophysiologic correlations

Upward and downward gaze palsy was measured by a magnetic search coil technique and correlated with neuropathologic findings in a patient with a unilateral midbrain infarct. Oculography demonstrated (1) saccadic palsy above primary position and slow, limited vertical saccades below; (2) low-gain, restricted vertical pursuit; and (3) low-gain, abnormal phase lead, and restricted range of the vertical vestibulo-ocular reflex (VOR). Bidirectional palsy of vertical saccades is attributed to unilateral loss of burst cells in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and interruption of burst cell fibers from the opposite riMLF. Pathways mediating vertical pursuit and integration of the vertical VOR also traversed the infarct, which included the interstitial nucleus of Cajal.     

A hypothetical scheme for the brainstem control of vertical gaze

OBJECTIVES: To develop a hypothetical scheme to account for clinical disorders of vertical gaze based on recent insights gained from experimental studies. METHODS: The authors critically reviewed reports of anatomy, physiology, and effects of pharmacologic inactivation of midbrain nuclei. RESULTS: Vertical saccades are generated by burst neurons lying in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). Each burst neuron projects to motoneurons in a manner such that the eyes are tightly coordinated (yoked) during vertical saccades. Saccadic innervation from riMLF is unilateral to depressor muscles but bilateral to elevator muscles, with axons crossing within the oculomotor nucleus. Thus, riMLF lesions cause conjugate saccadic palsies that are usually either complete or selectively downward. Each riMLF contains burst neurons for both up and down saccades, but only for ipsilateral torsional saccades. Therefore, unilateral riMLF lesions can be detected at the bedside if torsional quick phases are absent during ipsidirectional head rotations in roll. The interstitial nucleus of Cajal (INC) is important for holding the eye in eccentric gaze after a vertical saccade and coordinating eye-head movements in roll. Bilateral INC lesions limit the range of vertical gaze. The posterior commissure (PC) is the route by which INC projects to ocular motoneurons. Inactivation of PC causes vertical gaze-evoked nystagmus, but destructive lesions cause a more profound defect of vertical gaze, probably due to involvement of the nucleus of the PC. Vestibular signals originating from each of the vertical labyrinthine canals ascend to the midbrain through several distinct pathways; normal vestibular function is best tested by rotating the patient's head in the planes of these canals. CONCLUSIONS: Predictions of a current scheme to account for vertical gaze palsy can be tested at the bedside with systematic examination of each functional class of eye movements.     

Supranuclear gaze palsy and eyelid apraxia in postencephalitic parkinsonism

Summary We describe six patients with clinicopathologically confirmed postencephalitic parkinsonism (PEP) in whom oculomotor abnormalities developed several years after suffering the initial episode of encephalitis lethargica. Four of the cases had vertical supranuclear gaze palsy and two eyelid apraxia, features typically associated with progressive supranuclear palsy (PSP). Our findings indicate that the presence of gaze palsy alone may not be a reliable clinical discriminator between PEP and PSP. Involvement of the dorsal central gray nucleus, nucleus centralis pontis oralis, nucleus dorsal raphe interpositus, rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), nucleus interstitialis of Cajal, nucleus of the posterior commissure, pedunculopontine nuclei and frontal cortex was observed in several of our PEP cases and may contribute to the oculomotor abnormalities in this disorder. Whether the dorsal tegmental nucleus, caudal to the supratrochlear nucleus, severely affected in all our PEP cases, has a role in vertical gaze needs to be further studied.Abbreviations PSP progressive supranuclear palsy - NFTs neurofibrillary tangles - NPTs neuropil threads - riMLF rostral interstitial nucleus of the medial longitudinal fasciculus     

Supranuclear vertical gaze palsy: bilateral thalamo-mesencephalic lesions demonstrated by MRI

The exact location for the major control center of the vertical gaze, which is referred to as rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), has been documental in a few autopsy studies. However, CT in some of the case reports of vertical gaze palsy have not clearly delineated this nucleus and its nearby complex anatomical structures. Discrete small, bilateral, symmetric infarcts in the thalamo-mesencephalic junction were demonstrated by MRI in a 59-year-old female patient who had sustained vertical gaze palsy over a period of nine years. Neurological examination revealed severe supranuclear combined downward and upward vertical gaze palsy, incomplete convergence, and slight limitation in adduction of the right eye. There was neither ptosis, pupillary disturbance, nor any further abnormalities of horizontal eye movements. The vertical vestibulo-ocular reflex was maintained, being similar to the other reported cases of vertical gaze palsy. MRI has advantages over CT in demonstrating lesions in the thalamo-mesencephalic junction in the cases of vertical gaze palsy, because clearer sagittal images can be obtained.     

Supranuclear vertical gaze palsy and convergence nystagmus caused by unilateral riMLF lesion]

We report a case showing supranuclear vertical gaze palsy and convergence nystagmus caused by a unilateral lesion of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). The patient was a 54-year-old female with mitral stenosis and regurgitation and atrial fibrillation, who suddenly developed vertigo and double vision. She was admitted to our hospital because of persisting diplopia 4 days after onset, although vertigo had resolved within 1 hour. On admission she was alert, but presented with supranuclear vertical gaze palsy and convergence nystagmus. Other cranial nerves were intact and motor strength, deep tendon reflexes, sensations were also normal. There were no cerebellar signs. Cranial MRI demonstrated a unilateral ischemic lesion at the left thalamo-mesencephalic junction that involved the unilateral riMLF. Cerebral angiography revealed no abnormalities. Vertical gaze palsy has been reported to be caused by a lesion involving bilateral riMLF or unilateral posterior commissure, and convergence nystagmus usually by a lesion near or within the dorsal mesencephalon. However, recent reports have demonstrated a histopathologic evidence that vertical gaze palsy was caused by unilateral riMLF lesion. The present case confirms clinically that both vertical gaze palsy and convergence nystagmus can be developed by a lesion of unilateral riMLF.     

A case of partial fascicular oculomotor paresis caused by midbrain infarction]

We report a 74-year-old man with an ischemic lesion in the ventral midbrain. He presented with contralateral ptosis and marked upward gaze paresis of the right eye. Neurological examination revealed partial oculomotor nerve palsy caused by impairment of the right levator palpebrae, superior rectus and inferior oblique muscles. This finding is highly suggestive of a possible lesion in the midbrain affecting the oculomotor fascicular fibers. Magnetic resonance images showed an ischemic lesion in the paramedian area of the right midbrain tegmentum. The coronal view of T 2-weighted imaging clearly demonstrated to be the site of lesions below the red nucleus. It seemed to be coincidental with the impaired site of involving the caudal part of oculomotor fascicular fibers emerging from the nucleus. This report is considered to be a typical case of partial fascicular oculomotor paresis based on impairment of the caudal part of oculomotor fascicles for the levator palpebrae, superior rectus, and inferior oblique muscles. This is a valuable case to be documented in which neurological site of lesions are consistent with those found in radiological study.     

Isolated crossed superior rectus palsy in a midbrain infarction]

A 61-year-old man suddenly heard tinnitus and diplopia at night during watchinng television. A few days later he visited at our hospital. Neurologically he exibited marked isolated right superior rectus palsy which was also indicated by the Hess test. No other neurological abnormalities were found such as other ocular muscle paresis, cranial nerve palsies, hemiparesis, sensory impairement or cerebellar ataxia. MRI showed a left medial thalamic infarction extending to a rostral part of the midbrain anterolateral to the cerebral aqueduct at the superior colliculi level. Unilateral superior rectus palsy can rarely be caused by a contralateral midbrain infarction, because fibers from the subnucleus subserving the superior rectus decussate within the oculomoter nerve complex. In this case the crossing fibers toward the contralateral superior rectus may have been selectively involved by a tinny lesion in the area of the oculomotor nucleus. The patient had a slightly narrowed right palpebral fissure. It is indicated that crossing fibers toward the contralateral levator muscle of the eyelid may be also involved. The patient's diplopia completely resolved two months later after the onset.     

Vertical gaze palsy associated with bilateral ptosis following right putaminal hemorrhage

Previous reports suggest that right hemispheric lesions may produce a variety of disorders in eye opening, including bilateral eyelid ptosis. More recently, bilateral ptosis and a severe deficit of upward gaze while preserving the downward gaze have been reported in patients with right hemispheric infarction. In the present report, we describe 2 patients who showed downward gaze palsy in addition to upward gaze palsy, accompanied by bilateral ptosis following right putaminal hemorrhage. The 2 patients displayed acute onset of similar ocular manifestations, such as difficulty in eye opening, upward and downward gaze palsy, and conjugate horizontal deviation in addition to left hemiparesis. The principal cause of difficulty in eye opening was considered to be bilateral ptosis. Computed tomography performed on admission revealed a moderate-sized hematoma in the right putamen. There was no evidence of midbrain involvement. These ocular symptoms were restored within a few weeks after the onset of stroke. The ocular manifestations noted in our patients suggest that the descending pathways arising from the supranuclear centers to the midbrain, which control vertical movement of the eyes and the eyelids, may be impaired by putaminal hemorrhage. To our knowledge, this is the first report of such ocular manifestations in the right hemispheric lesion. Copyright © 2002 by National Stroke Association     

A neuro-Behcet's lesion in oculomotor nerve nucleus

OBJECTIVE: Fascicular oculomotor nerve involvement is occasionally seen in Behcet's disease, but nuclear involvement is very rare. CASE PRESENTATION: A 25-year-old woman presented with the Behcet's symptoms and the left eye problems. Physical examination revealed muco-cutaneous lesions, eyelid ptosis, mydriasis, upward and medial gaze palsy and lateral deviation on the left eye. Serologic tests were positive. An inflammatory lesion was detected in the left oculomotor nerve nucleus on magnetic resonance imaging. Neuro-Behcet's disease was considered the most likely diagnosis. RESULT: Dexamethasone treatment was ordered. Muco-cutaneal lesions, laboratory abnormalities were normalized after 1 year; but oculomotor nerve palsy persisted in spite of improvement in radiological findings. CONCLUSION: Clinical signs of oculomotor nerve palsy may persist despite the radiological improvement.     

Bilateral ptosis, bilateral upgaze and adduction paresis, and monocular downgaze paresis from a mesencephalic infarction]

We report a 57-year-old man with an ischemic lesion in the midbrain. In the acute stage, he presented with bilateral ptosis and markedly limited extraocular motion except for bilateral abduction and downward motion of the right eye. The pupillary reaction to light of his left eye also was impaired. He was admitted to our hospital, and brain MRI showed a small infarction extending from the left paramedian to the median tegmentum of the midbrain. Three weeks after admission, the ptosis and limited extraocular right eye motion had resolved. The pupillary reaction and downward motion of the left eye normalized gradually within 3 weeks. Two months after admission, ptosis and the limited left eye adduction were partially resolved, but the markedly limited upgaze of the left eye had not changed. Initial neuro-ophthalmologic findings suggested involvement of the caudal part of the oculomotor nucleus and the left oculomotor nerve within the midbrain. The pattern of neuro-ophthalmologic impairment seen in our patient led us to conclude that the caudal oculomotor nucleus and medial part of the fascicular fibers of the left oculomotor nerve probably recovered first, after which recovery of the fascicular fibers progressed laterally. The results of serial MRI were consistent with this interpretation.     

A case of midbrain and thalamic infarction showing Collier's sign in one side and blepharoptosis in the other side

A 68-year-old man was admitted to the hospital complaining of aphasia and right hemiparesis. Neurological examination revealed aphasia, right hemiparesis and ataxia in the left upper extremity. He showed striking ocular symptoms: intense retraction of the right eyelid (Collier's sign), complete ptosis of the left eyelid which might conceal Collier's sign, marked upward gaze palsy and slight downward gaze palsy. Vertebral angiography and MRI revealed an infarction in the left medial area and the left crus cerebri in the upper midbrain, the left subthalamic area inferomedially extending from the adjacent area to the posterior commissure and the medial area in the left thalamus resulting from occlusion of the left mesencephalic artery. From these MRI findings and the reports on pathological findings of patients with Collier's sign, we suggest that damage in the posterior commissure or its adjacent area may be responsible for the sign. Upward gaze palsy is often associated with Collier's sign because fibers mediating upward gaze may decussate in the posterior commissure. Third nerve palsy is also associated with the Collier's sign in some patients. The mechanism creating Collier's sign may be a disturbance of inhibitory fibers leading to the motoneuron pool of the levator muscle in the posterior commissure or its adjacent area.     

Oculomotor nerve palsy due to small midbrain infarct--functional topography based on MRI findings]

This is a report of 3 cases presented with oculomotor nerve palsy caused by small midbrain infarct. The aim of this report is to clarify the functional topography of intranuclear and intrafascicular portion of the oculomotor nerve with MRI. Three cases are 2 males and 1 female, ranging 51 to 68 years in age. Except for the long tract signs at the acute stage, cardinal sings were all eye-related, incomplete in 1 case and pupil sparing-type in 2 cases. In MRI, the size of the lesion extended 5 to 12 mm. In the incomplete palsy case, the infarction extended from the level immediately below the 3rd ventricle into the whole length of midbrain, whereas in the pupil-sparing types, more limited lesion excluding the upper part of the midbrain was noted. Anatomically the longitudinal size of the nucleus is 10mm and nerves functionally related to pupil reaction, eye motion and eyelid elevation are arranged in rosrocaudal order. Therefore, it is speculated that in midbrain, intrafascicular location of nerve fibers associated with pupil reaction is rostral and oculomotor nerve palsy of pupil sparing type is caused by the lesion excluding the rostral midbrain. MRI findings of the present 3 cases are compatible with this speculation. The lowest border of red nucleus is at the level of superior colliculus, whereas oculomotor nucleus has its lowest margin at the inferior colliculus. Therefore, red nucleus becomes an informative landmark to visualized the level of oculomotor nerve injury, since the red nucleus is clearly demonstrated in high intensity in T2 weighted image.     

Midbrain infarction presenting isolated inferior rectus nuclear palsy]

We presented a patient of isolated inferior rectus muscle palsy from midbrain lacunar infarction involving the oculomotor nucleus. The patient noticed sudden onset diplopia gazing to the right side, especially to the right-lower direction. He did not have any other symptom, and neurological examination revealed no other findings. Brain MRI documented the focal hyperintense lesion on T2-weighted images in the right-median midbrain ventral to the aqueduct at the level of the superior colliculus. This lesion involved the right oculomotor nucleus, especially the dorso-lateral subnucleus extend to the inferior rectus muscle. The oculomotor nuclear complex consists of one unpaired subnucleus and four paired subnuclei. Among them, the inferior rectus subnucleus lies dorso-laterally. So nucleus lesion may cause isolated weakness of one of muscles innervated by the oculomotor nerve. Among them the isolated inferior rectus muscle palsy can occur relatively.