Selective impairment of downward gaze; report of two cases of midbrain and bilateral paramedian thalamic infarction

Selective paralysis of downward gaze, first described by André-Thomas et al. in 1933, is rare to be observed and not many cases have been so far reported in the literature. Two additional cases of selective impairment of downward gaze have been reported. X-ray CT scan revealed the infarcted areas in the midbrain tegmentum and bilateral paramedian thalami in both cases. Angiographic studies have revealed that the arteries occluded might be the paramedian thalamic arteries and their mesencephalic branches. According to the reported clinico-pathological studies and, in addition, to the results of the physiological studies in animal models, the responsible site of lesion for downward gaze failure is thought to be the rostral interstitial nucleus of MLF (riMLF). In one of the cases (28 year-old female, case 1), while vertical slow pursuit eye movements and upward saccade were normal in speed and range, maximum speed of eyes in voluntary downward saccade was markedly reduced and the eyes moved down slowly as if moving in oil (slow eye movement, viscosité). Passively extending the patient's head while she tried to fix her eyes on an unmoving object (doll's eye phenomenon), the speed of her eyes in downward saccade did not increase. In the other case (45 year-old male, case 2), the patient's voluntary and reflex downward eye movements were completely impaired and he could not look down nor follow the object below extending the horizontal meridian level. With regard to the unique features of abnormal eye movements observed in our cases, the possibility of coexistence of saccadic and slow pursuit eye movement systems in the vertical plane was discussed.     

Monocular ophthalmoplegia and partial supranuclear vertical gaze palsy due to unilateral paramedian rostral midbrain infarction

Journal of Neurology -     

中脑被盖中央部梗死致共济失调两例报道

中脑被盖中央部梗死罕见,临床表现特异[1].现将山东省烟台市烟台山医院神经内科收治的2例患者报道如下. 例1男,55岁,因"头晕伴言语不清,行走不稳10d"于2007年8月10日入院.患者入院前10 d无明显诱因出现头晕,言语不清,伴复视,行走不稳,持物易落,持续几分钟后缓解,每日发作数次.发作时无视物旋转,无头痛、耳鸣及恶心、呕吐.     

Long latency responses in pure sensory stroke due to thalamic infarction

Objectives – Our study was designed to clarify the role of the thalamus in the generation of the electrically elicited long-latency reflexes (LLR) in voluntarily activated hand muscles. Materials and methods – EMG responses of the thenar muscles were evoked by electrical stimulation of the median nerve at the wrist at motor threshold intensity in 10 patients with acute pure sensory stroke due to thalamic infarction. Concomitant recording of somatosensory evoked potentials (SEPs) was performed. The subjects were asked to steadily abduct the thumb at 20–30% of maximal force against a force transducer. Rectified and averaged EMG activities were recorded. Results – The LLR II was missing completely or significantly attenuated in the majority of the patients (9 of 10), of whom 3 also had delayed latency. Abnormal SEPs were documented in 7 patients (7 of 10). In the follow-up, 5 patients had partial reversal of LLR II. LLR II was still pathological in 1 fully recovered patient. Conclusion – Our results further confirm the transcortical generation of LLR II and imply that a thalamic relay is present in the afferent limb of the LLR.     

Pure sensory stroke with lacunar infarction in the posterior ventral thalamus on CT

A hypertensive male patient is described who suffered a pure sensory stroke. CT revealed a small lacunar infarct in the contralateral posterior part of the ventral thalamus. This is the second described case with a CT verified single ischemic lesion restricted to the thalamus.     

Bilateral thalamic infarction. Clinical, etiological and MRI correlates

To determine clinical, behavioral, topographic and etiological patterns in patients with simultaneous bilateral thalamic infarction in varied thalamic artery territories, we studied 16 patients who were admitted to our stroke unit over a 7-year period. Patients with bithalamic infarction represented 0.6% of our registry which included 2,750 ischaemic stroke patients. On computed tomography and magnetic resonance imaging with gadolinium enhancement, there were 4 topographic patterns of infarction: 1) bilateral infarcts in the territory of paramedian artery (8 patients [50%]); 2) bilateral infarcts in the territory of thalamogeniculate arteries (3 patients [19%]); 3) bilateral infarcts involving territory of paramedian and thalamogeniculate arteries (3 patients [19%]); 4) bilateral infarcts involving territory of polar and thalamogeniculate arteries (2 patients [13%]). A specific clinical picture was found in up to 50% of the patients with bithalamic infarction. This included patients with bilateral paramedian infarction having disorder of consciousness, memory dysfunctions, various types of vertical gaze palsy and psychic changes. Bilateral sensory loss predicted accurately bilateral infarction in the territory of thalamogeniculate arteries. The main cause of bilateral thalamic infarction was small artery-disease, followed by cardioembolism. Cognitive functions in patients with bilateral paramedian infarction did not change significantly during the follow-up, in contrast to those with infarcts in varied arterial territories. Acute bilateral infarction involving both thalamus is uncommon, although they are often associated with specific neurologic-neuropsychological patterns, allowing diagnosis before radiological examination.     

Pure motor hemiplegia due to pyramidal infarction.

A 77-year-old man suddenly developed left hemiplegia without sensory impairment, visual or speech difficulties, loss of consciousness, or ataxia. He died one month later of pulmonary embolism, and a cystic infarction in the right medullary pyramid was the only lesion in the corticospinal system.     

Hemifacial spasm due to a tentorial paramedian meningioma: a case report

Abstract Hemifacial spasm (HFS) is a movement disorder characterised by involuntary paroxysmal facial movements that usually involve the orbicularis oculi and then spread to the other facial muscles. A microvascular compression and demyelination of the seventh nerve at its exit from the brain stem is considered to be the main aetiology of HFS. In addition to rare idiopathic (cryptogenetic) cases, others causes of HFS exist: tumours or vascular malformations have been described, of both the ipsilateral and contralateral cerebellopontine angle (CPA). However, space-occupying lesions in locations other than CPA are usually not thought to be responsible for HFS. Here we describe the case of a 45-year-old woman suffering from HFS, who dramatically improved after surgical removal of a tentorial paramedian meningioma.     

Chronic encephalitis possibly due to herpes simplex virus: two cases

Two patients had clinical findings of encephalopathy that progressed in 4 to 5 months. One patient had headache, fatigue, lethargy, hemiparesis, and a seizure. The second patient had only forgetfulness, confusion, and lethargy without focal signs. Herpes simplex virus was grown from brain biopsy in the first patient and from CSF in the second patient. These cases suggest that herpes simplex virus caused the encephalitis and that it should be considered in the differential diagnosis of chronic encephalopathy.     

Cerebral bloodflow and oxygen metabolism in borderzone and territorial infarcts due to symptomatic carotid artery occlusion

It remains controversial whether borderzone infarcts are due to compromised cerebral perfusion and whether territorial infarcts are caused by artery-to-artery emboli in case of occlusion of the internal carotid artery. The present positron emission tomography study compares with normal controls, the average regional cerebral bloodflow (rCBF), regional oxygen extraction fraction (rOEF) and regional cerebral metabolic rate for oxygen (rCMRO₂) in the infarct area, the peri-infarct zone, the remaining homolateral hemisphere and in the contralateral hemisphere of 10 patients with borderzone and 17 patients with territorial infarcts, due to internal carotid artery occlusion by atherosclerosis and by cervical dissection. The steady-state technique with oxygen-15 was used. A nearly significant increase of rOEF with lowered rCBF and rCMRO₂ was observed in the peri-infarct zone of patients with territorial infarcts. In patients with borderzone infarcts rCMRO₂ was decreased in the peri-infarct zone, in the remaining homolateral hemisphere and in the contralateral hemisphere without changes in rCBF and rOEF. The present study finds no arguments that impaired cerebral perfusion is a more frequent cause of borderzone than of territorial infarcts.     

Pain due to epidural tumor in cancer patients. Report of two cases and differential diagnosis

The cases of two patients with inguinal pain as the only symptom of a T12 metastatic lesion is reported. The patterns of pain referrals from tumor lesions to the spine, epidural space, and spinal cord are reviewed. Focal back pain and pain reported in a distal distribution can both be associated with epidural or cord disease. The differential diagnosis of back pain in patients with cancer can be difficult but may be crucial in differentiating important neurological complications of systemic neoplasms.Suported in part by Italian Research Council grant N. ACRO 96.00692.PF39 and Italian Association for Cancer Research grant N. AIRC 198512.     

Late onset unilateral asterixis secondary to posterior cerebral artery infarction

Unilateral asterixis developed in a 56 year old man, 5 months after an infarct in the posterior cerebral artery territory, involving the posterolateral nuclear complex of the thalamus, documented by CT-scan and MRI. Unilateral asterixis in rarely reported in association with thalamic lesions and usually develops as an immediate postictal phenomenon. We discuss possible physiopathological mechanisms explaining the occurrence and the delayed onset of these involuntary movements.

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Sommario Un uomo di 56 anni ha sviluppato un'asterixis unilaterale, 5 mesi dopo aver presentato un infarto nel territorio dell'arteria cerebrale posteriore, che coinvolgeva i nuclei postero-laterali del talamo, come evidenziato dalla TC e dalla MRI. Asterixis unilaterali si sviluppano raramente in seguito a lesioni vascolari a livello del talamo e generalmente rappresentano un evento immediatamente successivo all'ictus. Nel caso descritto invece, i movimenti involontari si sono manifestati a notevole distanza di tempo. Gli autori discutono i possibili meccanismi fisiopatologici alla base di questi movimenti involontari e della loro insorgenza a distanza di tempo dall'ictus.

     

Spinal cord infarction due to minor trauma in children.

In two children, ages 22 months and 4 years, after slight trauma, flaccid weakness of both arms developed, followed by flaccid quadriplegia with sphincter involvement. No vertebral fracture or dislocation was found, myelograms were negative, and diagnosis was made only after the full clinical syndrome developed. Pathologic studies revealed ischemic infarction involving the cervical cord and low medulla in one patient, and central gray matter of low cervical cord in the other, without hematomyelia or external compressive lesions. The pattern of infarction may be related to spasm of distal branches of the central sulcal arteries in a terminal arterial bed.     

Leptomeningeal cyst in newborns due to vaccum extraction: report of two cases

Two new cases of leptomeningeal cysts subsequent to vacuum extraction are reported. Both children presented with a huge, nonpulsating, transilluminating subgaleal collection over the anterior fontanel that appeared soon after instrument delivery. Plain X-rays, computed tomography, and magnetic resonance imaging confirmed that the subgaleal collection was cerebrospinal fluid and showed the presence of a diastatic coronal suture in both cases. Treatment consisted of duraplasty with periosteal flaps and application of fibrin glue. In one case, an associated porencephalic cyst was treated with a cystoperitoneal shunt. Surgical treatment of leptomeningeal cyst due to vaccum extraction is simple and should not be postponed, despite the tendency for the extracrainal cyst to regress, because of the potential risk of continuous growth of an underlying porencephalic cyst and risk of neurological damage.