Intra-axial involvement of the common oculomotor nerve in mesencephalic infarctions

Mesencephalic infarcts are rarely limited to the midbrain, and usually extend rostrally to the thalamus. This fact explains why an elective palsy of the oculomotor nerve is exceedingly uncommon in brainstem infarcts. We studied 4 cases with a unilateral infarct apparently restricted to the middle mesencephalon, with intra-axial involvement of the oculomotor nerve. In 2 cases with a fascicular lesion, there was a contralateral hemiparesis or hemi-ataxia, so that it is possible to term them Weber's syndrome and Claude's syndrome. In the 2 other cases, we suggest that a nuclear syndrome of the oculomotor nerve was present, because of bilateral involvement of the rectus superior in both cases, of the levator palpebrae in one case, and of the parasympathetic pupillary fibres in the other, although the infarct was unilateral. There are several clinical variants of the intra-axial syndrome of the oculomotor nerve which can be differentiated according to the uni or bilaterality of the oculomotor palsy, the pupillary disturbances, and the type of associated neurological dysfunction. The nuclear syndrome corresponds to an infarction of the median arterial area, which is directly supplied by the most distal part of the basilar artery. The fascicular syndromes correspond to infarction of the paramedian and intermediolateral areas supplied by the first part of the posterior cerebral artery (basilar communicating or mesencephalic artery). As the paramedian thalamic arteries also originate from the basilar communicating artery, most infarcts also involve the upper midbrain and the thalamus, producing supranuclear oculomotor disturbances.(ABSTRACT TRUNCATED AT 250 WORDS)     

Localization of Claude's syndrome.

Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.     

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.     

Two cases of neuro-Behcet's disease mimicking cerebral tumor

Two cases of neuro-Behcet's disease with isolated, solitary fronto-temporal and mesencephalic lesions respectively are reported. The cases were misdiagnosed as cerebral tumor. The postoperative outcome of the first patient was not satisfactory as he developed hemispheric edema. The second patient, with mesencephalic lesion, was treated only with corticosteroids, and the patient improved significantly. The lesion in this case resolved completely at six-month follow-up. We conclude that distinguishing the isolated solitary cerebral lesion of the Behcet's disease from a tumor may prevent surgical intervention.     

A reticulo-frontal disconnection syndrome

Persistent executive deficit, usually seen following prefrontal damage, is reported in a patient recovering from head trauma. Repeated neuroradidological examinations failed to reveal a lesion within the frontal lobes, but a circumscribed lesion in the ventral mesencephalic tegmentum was found. It is proposed that the observed syndrome was caused by damage to mesencephalic reticular nuclei and their projections into prefrontal cortex. The concept of a "reticulo-frontal disconnection syndrome" is introduced and its possible role in head trauma and schizophrenia discussed.     

Alternating oblique deviation of the gaze. 3 cases

Three cases of alternating skew deviation of gaze are reported. In two patients, it was associated with oculomotor disorders suggestive of a medial mesencephalic lesion. CT scan showed 3rd ventricule abnormalities accounting for the mesencephalic involvement. The third patient had a tuberculous meningo-encephalitis with basal symptoms. The pathophysiological mechanisms of the vertical interocular divergence is discussed. It was probably related to a bilateral disorder of the superior recti and an overaction of the inferior obliques. It suggested a medial supranuclear dysfunction.     

Dementia following strokes in the mesencephalon and diencephalon

Six patients had ischemic infarcts in the paramedian thalamic, subthalamic, and mesencephalic areas. In addition to ocular motility problems, ataxia, dysmetria, and mild pyramidal signs, there were consistent behavioral observations and neuropsychological findings. All of the patients had initial deficits in arousal, and gradually improved to normal wakefulness. When awake, all of the patients had impaired attention, mental control, and slowed verbal and motor responsiveness. They were apathetic, poorly motivated, and affect was flat or occasionally labile. All of the patients had a memory disorder characterized by anterograde and retrograde loss. One patient had significant language impairment. These deficits persisted in all but one patient who had a predominantly mesencephalic lesion. We believe the cluster of findings in these patients constitutes a characteristic syndrome of dementia related to paramedian mesencephalic and diencephalic infarcts. This syndrome bears close resemblance to that associated with some subcortical degenerative disorders such as progressive supranuclear palsy. In cases of paramedian mesencephalic and diencephalic infarcts, however, computed tomography and magnetic resonance imaging can delineate clinicoanatomic relationships that account for specific constituents of the syndrome.     

Computed tomography and pure motor hemiparesis

Computed tomography (CT) was abnormal in 75% of 33 patients with pure motor hemiparesis (PMH). In 13 cases, lesions were detected in the capsular region; 10 were consistent with infarction, and 3 were of increased density consistent with hemorrhage. Seven had other vascular disorders, and four had nonvascular conditions. Of 20 patients with PMH with normal electroencephalogram (EEG), isotope scan, and cerebrospinal fluid, 11 had CT evidence of a lesion in the internal capsule-corona radiata region. In patients with PMH with normal CT, recovery was more complete and rapid than in those with CT evidence of a vascular lesion. In 5 cases, CT showed a capsular lesion, although the patients had never had any neurologic deficit.     

Painful ataxic hemiparesis

Right hemiparesis with right-sided pain and ataxia developed in a 68-year-old man. Sensation, neuropsychological function, and somatosensory evoked potentials were normal. Computed tomography showed an isolated fresh infarct in the left part of the thalamus. The pain and ataxic disturbances were related to involvement of the thalamus itself, but the hemiparesis with hyperactive tendon reflexes and Babinski's sign was probably due to associated dysfunction in the adjacent internal capsule from compression or edema. In the available clinicopathological reports of cases with hemiparesis and thalamic infarction, contiguous involvement of the internal capsule or no associated lesion has been reported. Because of the occurrence of pain, which is not present in pontine, mesencephalic, or capsular ataxic hemiparesis, we suggest that the syndrome seen in our patient be called "painful ataxic hemiparesis."     

Ocular bobbing. A new hypothesis

Three of 4 patients with ocular bobbing were typical cases while in the last case the ocular disorder was asymmetric. A neuropathologic study was conducted in 2 cases. In both use, findings included variable degrees of pontine destruction without lesion of the medulla, with extension of the lesion into the mesencephalon in 1 case. The various physiopathogenic hypotheses put forward are reviewed but none appears satisfactory. A new hypothesis is proposed, based on available clinico-pathologic data (35 published and 2 personal cases) and recent experimental studies. Two centers, one mesencephalic, the other in the medulla, could exist that would generate saccadic movements downwards, and in the pons a center would provoke inhibition of saccadic movements. Destruction of the latter could activate spontaneous saccadic movements downwards (the only possible ones remaining) with the condition that the mesencephalic generating center and its pathways are intact.     

Primary central neurocytoma of the mesencephalic tectum in a pediatric patient

Purpose

Neurocytomas are tumors or neuronal differentiation, typically located within the supratentorial ventricular system. The extraventricular location is uncommon. A limited number of cases involving the brainstem have been reported and may be misdiagnosed as brainstem gliomas. Furthermore, midbrain neurocytomas are extremely rare, and no similar cases in pediatric patients have been reported in the literature to date. Brainstem location of neurocytomas often precludes gross total removal of the lesion, and in these cases, adjuvant therapies may be helpful.

Methods

We report a case of a 16-year-old child who presented with signs and symptoms of increased intracranial pressure. The magnetic resonance imaging study demonstrated the presence of a primary mesencephalic tectum lesion causing obstructive hydrocephalus. The patient underwent emergent ventriculoperitoneal shunt implantation, resolving the hydrocephalus and the clinical symptoms. The lesion was partially removed through a suboccipital craniotomy and supracerebellar infratentorial approach to the mesencephalic tectum, without intraoperative complications.

Results

Histological examination of the lesion was consistent with the diagnosis of extraventricular neurocytoma. The patient was referred to the oncology department for additional treatment with Gamma Knife radiosurgery.

Conclusions

Although brainstem neurocytoma is rare, this case demonstrates that it should be included in the differential diagnosis of brainstem gliomas. Because of brainstem tumor location, complete surgical removal may be challenging or not possible, with a high risk of postoperative neurological deficits. Adjuvant therapies may prevent local tumor growth in cases of tumor remnants or recurrences following microsurgery in selected cases.     

Plus-minus lid syndrome.

A patient presented with ipsilateral ptosis and contralateral superior eyelid retraction due to a nuclear third nerve syndrome. The CT brain scan revealed a paramedian mesencephalic lesion contiguous with the oculomotor nucleus, sparing the midbrain tectum and the posterior commissure.     

A case of Sj?gren's syndrome with subacute transverse myelitis as the initial manifestation]

We report a case of subacute transverse myelitis associated with Sj?gren's syndrome free of xerosis. A 62-year-old man was admitted due to dysesthesia of both lower extremities and the left trunk, weakness of the left leg, and urinary disturbance. Neurological examination showed myelopathy at the Th7 level. CSF had increased protein (82 mg/dl) and IgG (23.4 mg/dl) and IgG index (1.03) but an almost normal cell count (7/mm3). T2-weighted MRI showed a high signal intensity lesion at the sixth and seventh thoracic levels. Although he was free of xerosis, typical sialographic findings, as well as the presence of anti-SSA antibody, are consistent with the diagnostic criteria for Sj?gren's syndrome decided by the Japanese research group on Sj?gren's syndrome. The patient was treated with prednisolone, 60 mg/day, which completely cured his muscle weakness and difficulty in walking, and sensory disturbance was gradually alleviated. Spinal MRI detected a marked reduction in the size of T2-weighted high signal intensity lesion during prednisolone treatment. In Western countries, central nervous system complications are reported in up to 20% of Sj?gren's syndrome patients, but myelopathy is a very rare condition. Only 12 cases, including ours, have been reported. The clinical manifestations of myelopathy in Sj?gren's syndrome include acute or subacute transverse myelitis (6 cases, including ours), chronic progressive myelopathies (2 cases.), relapsing and remitting cord syndromes (4 cases) and Brown-Séquard syndrome (none). Ten patients were women. In 9 of 12 cases there were sicca symptoms. The level of the myelopathies in 6 of 10 cases was between the third to eighth thoracic level, consistent with the region vulnerable to ischemia. Eight patients were treated successfully with steroids. We speculate that ischemia due to vasculitis is important in the genesis of myelopathy associated with Sj?gren's syndrome. In the case of myelopathy, especially in the thoracic cord, it is necessary to look for evidence of Sj?gren's syndrome even when xerosis is unremarkable.     

Bilateral third cranial nerve palsy triggered by an acute relapse of multiple sclerosis

INTRODUCTION: We report a case of bilateral third cranial nerve palsy in a patient with a secondary progressive multiple sclerosis. OBSERVATION: MRI revealed a large hyperintense lesion in T2-weighted images in the mesencephalic area. The clinical and radiological outcome was good after intravenous methylprednisolone. The oculomotor signs were probably caused by this mesencephalic lesion. CONCLUSION: This case of bilateral third cranial nerve palsy is, to our knowledge, the first one occurring in a patient with multiple sclerosis.     

Spastic pure motor monoparesis

Pure motor hemiplegia (PMH) is, in most cases, caused by a lacunar infarction. However, pure motor monoparesis (PMM), i.e., isolated motor involvement with spasticity in one limb, has drawn little attention. We studied prospectively 5 patients with PMM and found that it was always due to a mass lesion in the contralateral superficial cerebral hemisphere. Our observation suggests that PMM should not be regarded as simply a variant of PMH.     

Delayed finger opening caused by a midbrain lesion]

We report a 25 year-old woman with delayed finger opening caused by a midbrain lesion. Magnetic resonance imaging revealed an abnormal intensity area in the left midbrain in the vascular territory corresponding to the mesencephalic inferomedian branch and central posteromedian branch of posterior cerebral artery. Clinically, she suffered from Weber's syndrome, and in the course of recovery, she developed marked delayed finger opening. Her weakness was slight, this delayed finger opening was observed only after maximal grip, and she required about ten seconds to open her right fingers. She could open and grip her fingers easily and quickly in moderate contraction. In the electromyogram, the action potentials of flexor digitorum profundus muscle did not disappear promptly upon instruction to open her fingers, and they lasted for approximately six seconds with gradual decrease. On the other hand, the action potentials of extensor digitorum muscle were reciprocally inhibited and increased gradually after the decrease of the flexor muscle potentials. The abnormally continuing discharges in the flexor muscles were thought to be the cause of her delayed finger opening. The phenomenon of delayed finger opening caused by cervical root lesions, peripheral nerve lesions, or a brain stem (pons-medulla oblongata) lesion have been reported. But, the phenomenon caused by a midbrain lesion, like our case, has not been reported. The present case was different from the previously reported cases with this phenomenon showing simultaneous discharges from both agonistic and antagonistic muscles.     

Syndrome of the mesencephalic artery: report of a case with CT and necropsy findings.

The syndrome of the mesencephalic artery refers to the clinical constellation of akinetic mutism and third nerve palsy which results from occlusion of one or more of the posterior thalamo-perforating arteries that arise from the proximal posterior cerebral artery. A patient with this syndrome is described in whom a bilateral paramedian midbrain infarct was shown by computed tomography and confirmed pathologically. To our knowledge, this is only the second reported case of mesencephalic infarct shown by computed tomography and the first in which the CT findings have been corroborated by pathological examination.     

Mesencephalic haematoma: case report with autopsy study

Summary A 70-year-old hypertensive woman suffered sudden onset of bilateral blepharoptosis. Within a few hours she developed focal signs attributable to a lesion of the mesencephalon, and a stuporous state, from which she did not recover. Neuropathological examination showed a mesencephalic haematoma, but no arteriovenous malformation. A review of reported cases suggests that mesencephalic haematomas have a worse prognosis when they occur in aged hypertensive patients, as compared with younger normotensive patients, in whom they are probably related to arteriovenous malformations.     

Bilateral cheiro-oral syndrome following pontine haemorrhage

Summary Cheiro-oral syndrome is a peculiar sensory disturbance observed around the corner of the mouth and the palm of the hand on the same side, usually occurring unilaterally. A male patient with bilateral cheiro-oral syndrome following pontine haemorrhage is reported. CT, MRI and neurological findings showed that the syndrome was due to a lesion in the medial lemniscus and ventral secondary ascending tract of the trigeminal nerve on both sides. Although unilateral cheirooral syndrome has been reported with a lesion in the parietal lobe, thalamus or brain stem, a bilateral syndrome could be caused only by a lesion of the brain stem.     

Myokymia and facial contracture in brain stem tuberculoma. A clinicopathologic report

The syndrome of persistent facial myokymia and spastic facial contracture is a rare sign of pontine glioma. In none of the previously published cases has this syndrome been reported in association with a nonneoplastic lesion. A patient is described in whom facial myokymia and contracture were caused by a pontine tuberculoma.