Brainstem Hemorrhage Research Articles

Transoral transclival removal of anteriorly placed cavernous malformations of the brainstem

BACKGROUND The natural history of brain stem cavernous malformations is unfavorable because of their high hemorrhage rate and resulting neurological deterioration among patients. However, direct surgery of intrinsic and anteriorly situated cavernomas is hazardous and leads to a bad postoperative outcome because of trauma to lateral and dorsally situated eloquent areas of the brain stem. METHODS We review the cases of two patients with symptomatic cavernous malformations of the anterior brain stem and describe the usefulness of a transoral-transclival approach. A 23-year-old man developed progressive hemihypaesthesia and paraesthesia, hemiparesis with gait ataxia, dysarthria, dysphonia, and dysphagia. A 38-year-old woman suffered from an acute onset of vertigo with nausea and vomiting, diplopia, and paraesthesia of the left hand and foot. In both patients, computed tomography demonstrated the presence of brain stem hemorrhage, because of cavernous malformation. Magnetic resonance imaging showed a close proximity of the lesions to the pia mater only on the ventral surface of the brain stem. RESULTS In both patients, the cavernomas could be safely approached and completely resected via a transoral transclival route. Three months after surgery, neurological examination revealed marked neurological improvement. The 23-year-old patient showed slight gait ataxia, no hemiparesis, no cranial nerve palsies; the 38-year-old woman demonstrated no neurological symptoms except for minimal motor dysfunction of the left hand. In both cases, under perioperative prophylactic antibiotics, no meningitis was observed. The patients could subsequently return to their previous employment. CONCLUSION The transoral transclival approach for ventrally situated brain stem cavernomas allows a largely atraumatic resection of the lesion.

Clinical Study of Vestibular-evoked Myogenic Potentials and Auditory Brainstem Responses in Patients with Brainstem Lesions

A total of 13 patients, who were diagnosed with localized brainstem lesions using MRI, were investigated. The diagnoses were multiple sclerosis in five patients, brainstem hemorrhage in three patients, pontomedullary infarction in one patient and Wallenberg's syndrome in four patients. In addition, 42 ears of 21 normal adult volunteers were also examined. In a patient with upper brainstem lesions mainly affecting the midbrain, the auditory brainstem response (ABR) was abnormal but the vestibular-evoked myogenic potential (VEMP) was normal. In four patients with middle brainstem lesions which mainly affected the pons, both ABR and VEMP were abnormal. In five patients with lower brainstem lesions which mainly affected the medulla, the ABR was normal but the VEMP was abnormal. In those patients with middle-to-lower brainstem lesions, a disappearance of VEMP reactions, delay of the positive-negative (PN) wave, increase in PN interpeak latency and decrease in PN amplitude on the affected side were confirmed. In conclusion, the VEMP test comprises a useful new diagnostic method for identifying lower brainstem lesions.

Improvement in Paramedic Examination Skills Following a Stroke Course

P184 Introduction: The need to decrease time to treatment for acute stroke patients means that prehospital providers must play an increased role in their care. This is possible only if emergency medical services personnel are able to rapidly recognize and assess patients with neurologic syndromes. Purpose: To assess the performance of a focused neurologic exam by prehospital providers before and after participation in an interactive stroke course. Methods: We developed a 1-day emergency stroke course that consists of 2 hours of lectures and 6 hours of interactive instruction, including small-group sessions led by paramedic instructors as standardized patients (SPs) portraying 5 key neurologic syndromes: left hemisphere, right hemisphere, brainstem, cerebellum, and subarachnoid hemorrhage. We devised a 53-point skills checklist to evaluate paramedic performance of history, exam, management, and emergency department (ED) reporting during 2 pre- and 2 postcourse encounters with actors portraying one of 4 scenarios: left hemisphere stroke, right hemisphere stroke, right hemisphere seizure with postictal hemiparesis, and left hemisphere tumor with sudden worsening. Among the 53 total skills evaluated were 28 exam-related items, including traditional paramedic exam items such as pupil reaction, hand grasp, and foot strength and additional items from the Miami Emergency Neurologic Deficit (MEND) Exam. We randomly selected 46 of 281 learners to participate in the study. Results: Checklist scores for neurologic exam performance improved significantly. The precourse mean score for the 46 learners was 3.38 (12.1%) and the postcourse mean was 21.4 (76.4%) (p<.001). Conclusions: Paramedics significantly improved their performance of a focused neurologic exam after attending a stroke course utilizing paramedic instructors as SPs with key stroke syndromes. We conclude that prehospital providers can learn and perform a brief, focused neurologic exam after attending a 1-day stroke course that emphasizes hands-on instruction. We are continuing to evaluate the effect of the course on the history-taking, ED-reporting, and stroke-management skills of practicing paramedics.

Intramedullary hemorrhage caused by arteriovenous malformation: A case of mixed lateral and medial medullary syndrome

A 48-year-old man with no known risk factor for cerebrovascular disease, other than cigarette smoking, experienced the sudden onset of a mixed lateral and medial medullary syndrome. Computed tomography scan failed to show any definite abnormality. Magnetic resonance imaging scans revealed hemorrhage restricted to the left dorsolateral medulla. Angiography showed abnormal arteries originating from the left vertebral artery with small niduses located on the surface of the medulla and contralateral cerebellum. Small brain-stem hemorrhages are a contraindication to thrombolytic or anticoagulant therapy, and therefore must be recognized in the acute stage. Copyright © 2001 by National Stroke Association

Distribution of dopamine-immunoreactive fibers in the rat brainstem

We describe the distribution of axons immunoreactive for dopamine in pons and medulla oblongata of rat under normal conditions or after inhibition of monoamine oxidase or dopamine β-hydroxylase. In the pons of non-treated animal, fairly dense plexuses of dopamine-immunoreactive varicose fibers were found in the locus coeruleus, dorsal parabrachial and dorsal raphe nuclei, central gray and reticular formation dorsal to the superior olive. In the medulla oblongata, the immunoreactive fibers were abundant in the dorsal vagal complex, lateral paragigantocellular nucleus, midline raphe nuclei and spinal trigeminal nucleus. Monoamine oxidase inhibition made it possible to increase the intensity of immunoreactivity and consequently the number of labeled fibers in these areas, indicating that dopamine is perpetually oxidized by monoamine oxidase, and consequently in low concentration under normal conditions. Sparse dopamine-immunoreactive fibers were observed in the pontine gray, motor trigeminal nucleus, inferior olive and major axon bundles such as the dorsal and ventral tegmental bundles, where numerous noradrenergic fibers have been reported. In axons of these areas, intense dopamine-immunoreactivity was seen only after inhibition of dopamine-β-hydroxylase. It appears that dopamine is released and oxidized in response to autonomic changes such as hypoxia, hemorrhage, and cardiovascular variation in the caudal brainstem, as we have described elsewhere.

Brainstem Hemorrhage Following Acute Necrotizing Encephalopathy

Brainstem Hemorrhage Following Acute Necrotizing Encephalopathy

Improvement in Paramedic Examination Skills Following a Stroke Course

P184 Introduction: The need to decrease time to treatment for acute stroke patients means that prehospital providers must play an increased role in their care. This is possible only if emergency medical services personnel are able to rapidly recognize and assess patients with neurologic syndromes. Purpose: To assess the performance of a focused neurologic exam by prehospital providers before and after participation in an interactive stroke course. Methods: We developed a 1-day emergency stroke course that consists of 2 hours of lectures and 6 hours of interactive instruction, including small-group sessions led by paramedic instructors as standardized patients (SPs) portraying 5 key neurologic syndromes: left hemisphere, right hemisphere, brainstem, cerebellum, and subarachnoid hemorrhage. We devised a 53-point skills checklist to evaluate paramedic performance of history, exam, management, and emergency department (ED) reporting during 2 pre- and 2 postcourse encounters with actors portraying one of 4 scenarios: left hemisphere stroke, right hemisphere stroke, right hemisphere seizure with postictal hemiparesis, and left hemisphere tumor with sudden worsening. Among the 53 total skills evaluated were 28 exam-related items, including traditional paramedic exam items such as pupil reaction, hand grasp, and foot strength and additional items from the Miami Emergency Neurologic Deficit (MEND) Exam. We randomly selected 46 of 281 learners to participate in the study. Results: Checklist scores for neurologic exam performance improved significantly. The precourse mean score for the 46 learners was 3.38 (12.1%) and the postcourse mean was 21.4 (76.4%) (p<.001). Conclusions: Paramedics significantly improved their performance of a focused neurologic exam after attending a stroke course utilizing paramedic instructors as SPs with key stroke syndromes. We conclude that prehospital providers can learn and perform a brief, focused neurologic exam after attending a 1-day stroke course that emphasizes hands-on instruction. We are continuing to evaluate the effect of the course on the history-taking, ED-reporting, and stroke-management skills of practicing paramedics.

第２５回日本脳卒中学会による前向き調査集計結果

The results of a prospective cooperative multi center study on hypertensive intracerebral hemorrhage in Japan are reported. Nine neurosurgical centers participated in this study during from January to December 1999. Total of 717 cases were registered and followed up for one month. Among then, 603 cases were admitted on day 0. Neurological grade at admission were as follows ; grade-1, 354 cases ; grade-2, 78 cases ; grade-3, 49 cases ; grade-4a, 43 cases ; grade-4b, 79 cases ; grade 5, 39 cases. 510 cases (73.2%) were treated conservatively and 185 cases (26.8%) were treated surgically. Incidences of surgical treatment and method of surgical evacuation of the hematoma such as craniotomy or trepanation were variable in each center. Brain stem hemorrhage showed the worst prognosis and subcortical and cerebellar hemorrhage were the better results. Incidence of mortality was less and morbidity was higher in the cases of surgical treatment.

Magnetic evoked potentials in neurocritical care patients with acute brainstem lesions

Motor evoked potentials (MEPs) are widely used in various neurological diseases, but have not been systematically employed in neurocritical care patients. We evaluated the clinical and predictive value of MEPs by magnetic transcranial stimulation in intensive care patients with acute brainstem lesions of predominantly vascular origin. In a prospective trial, a total of 30 patients with acute brainstem lesions were studied. Diagnoses were brainstem infarction (n=15), brainstem hemorrhage (n=3), encephalitis (n=1), basilar artery aneurysm (n=1), and space-occupying cerebellar infarct (n=5), cerebellar hemorrhage (n=3), and brainstem contusion (n=2). We performed MEP tests by transcranial stimulation to the abductor pollicis brevis bilaterally, bilateral somatosensory (SEPs) and auditory evoked (BAEPs) potentials. We determined motor function at the time of electrophysiological testing and after 3 months, the presence of radiologically confirmed lesions, and clinical outcome after 3 months. At the time of MEP recordings, ten patients were comatose, twelve stuporous, seven somnolent and one awake. MEPs were present bilaterally in seventeen, absent unilaterally in eight and bilateral absent in five patients. Absent MEP highly correlated with the presence of persisting motor deficit 3 months later (P<0.0001). Absent MEPs predicted motor deficit after 3 months with a high specificity and more precisely than the clinical examination at the time of MEP testing. MEP findings correlated with the presence of radiologically confirmed lesions within the brainstem (P<0.0001). Combined with SEP and BAEP data, MEPs predicted the presence of unilateral brainstem lesions with high accuracy. MEP recordings can be safely performed in neurointensive care patients and yield utilizable results. In patients with brainstem lesions, MEPs correlate with radiological findings and predict final motor function more accurately than clinical findings. MEPs are a reliable diagnostic tool for assessing motor function in otherwise unresponsive patients.

Olivary degeneration after intracranial haemorrhage or trauma: follow-up MRI.

We studied serial MRI appearances of transneuronal degeneration in the inferior olives, retrospectively analysing follow-up images of five patients, three with head injury and two with brain stem haemorrhage. We performed 13 MRI studies 4 days to 2 years 7 months after the accident. All but one of the patients exhibited bilateral olivary high signal on T2-weighted images. The interval between causal event and appearance of olivary changes was 2-4 months, images 4 days to 1.5 months after the accidents revealing no changes. Olivary enlargement was observed in four patients 2-4 months after ictus.

424 III – VI – VII cranial nerve disorders in a patient suffering from hemorrhage in brainstem: Blink reflex and BAEP's study

424 III – VI – VII cranial nerve disorders in a patient suffering from hemorrhage in brainstem: Blink reflex and BAEP's study

Management of Spontaneous Brain Stem Hemorrhage with Special Consideration to Vascular Malformations: Conservative versus Surgical Treatment

Management of Spontaneous Brain Stem Hemorrhage with Special Consideration to Vascular Malformations: Conservative versus Surgical Treatment

Hyperthermia in brain hemorrhage

Hemorrhage in the midbrain and/or pons in patients is often associated with increased metabolism, resulting in hyperthermia. We have recently reported that hyperthermia develops in anesthetized rats following prepontine knife-cuts or procaine microinjections into the midbrain or upper pontine region. It was concluded that the hyperthermia in the animals was caused by the removal of a tonic inhibitor mechanism of heat production that exists in the lower midbrain. The present paper proposes a new hypothesis that the hyperthermia in patients with brainstem hemorrhage is caused by disinhibition of heat production due to the release of such a lower-midbrain mechanism.

Bilateral cheiro-oral syndrome

Eight cases of pure bilateral cheiro-oral syndrome (COS) are reported. The location and etiology of lesion were well defined in six cases, including pontine infarct in three, and brainstem hemorrhage, unilateral thalamic infarct and bilateral subdural hematoma in one patient each respectively. Neuroimaging and neurophysiological studies were normal in another two patients. Taken together with the previous five reported cases of bilateral COS, pons is the most frequent site for presentation even in the absence of associated brainstem signs.

P487 Heart frequency variability in a patient with pontine brain stem haemorrhage (a course study)

P487 Heart frequency variability in a patient with pontine brain stem haemorrhage (a course study)

Auditory Deficits and Hearing Loss Associated with Focal Brainstem Haemorrhage

Four cases of central pontine haemorrhage are described in which auditory dysfunction was documented. Two cases had a hearing loss, in one of which there was recovery of the low frequencies. This case provides support for the tonotopic organization of the auditory pathways in the caudal pontine area, with the lowest frequencies being encoded medially. In all cases, there were abnormalities of the auditory brainstem responses, wave V being consistently involved, while wave III was abnormal in only one patient. In three cases, the masking level differences and crossed acoustic reflex thresholds were abnormal. The ipsilateral reflex thresholds were normal at least on one side in all cases. In the patient with the most significant hearing loss, loudness recruitment, assessed both psychophysically and with the acoustic reflex thresholds, was evident. These data are interpreted in terms of there being damage to the medial superior olivary nuclei and trapezoid body involving both afferent and efferent fibres.

Auditory Deficits and Hearing Loss Associated with Focal Brainstem Haemorrhage

Auditory Deficits and Hearing Loss Associated with Focal Brainstem Haemorrhage

Treatment of Acquired Nystagmus with Botulinum Neurotoxin A

Objective: Acquired nystagmus may cause oscillopsia and in some cases decreased visual acuity. Such symptoms may be debilitating. We evaluated the efficacy of retrobulbar botulinum neurotoxin A in the visual rehabilitation of patients with acquired symptomatic nystagmus. Patients: Adults with acquired nystagmus from multiple sclerosis or brain-stem hemorrhage were recruited for this treatment study. Eligible patients were unable to perform visual tasks that they had performed prior to the onset of the nystagmus. Design and Intervention: A prospective study evaluated the results of the retrobulbar injection of 25 to 30 U of botulinum neurotoxin A. Patients underwent testing of visual function, including eye movement recordings before and after initial injections. Patients were followed up for changes in their visual function for at least 6 months following the last injection. Results: Six patients (nine eyes) with acquired nystagmus were treated with a series of 17 injections of retrobulbar botulinum neurotoxin A. Each patient had subjective and objective improvement in distance visual acuity following the injection. A reduction in the amplitude of the nystagmus was seen following each of the injections, but the frequency of the nystagmus was generally unchanged. Visual improvement usually lasted no more than 8 weeks. However, improvement persisted for 6 months after injection in two patients with oculopalatal myoclonus. Conclusion: Botulinum neurotoxin A transiently improves the visual function of patients with acquired nystagmus. For patients with oculopalatal myoclonus the improvement seems to last longer, about 6 months in two patients.

Torsade de pointes and T-wave alternans in a patient with brainstem hemorrhage

Torsade de pointes, a form of life-threatening ventricular arrhythmia associated with QT prolongation, is rarely reported in intracranial hemorrhage. T-wave alternans is recently considered a risk marker for ventricular arrhythmias. To our knowledge, we report the first case of brainstem hemorrhage in which the patient presented with torsade de pointes and T-wave alternans. The implication of this association is discussed.

Brain-stem auditory evoked potential monitoring. Variations of stimulus artifact in brain death

Brain-stem auditory evoked potentials (BAEPs) were recorded in 20 subjects with brain death (mean age, 33.2 ± 15.1 years) and 20 healthy volunteers (mean age, 29.8 ± 6.8 years). Brain death was due to head injury (n = 14), encephalitis (n = 3), brain-stem hemorrhage (n = 1), cerebellar hemorrhage (n = 1) or cerebral infarction (n = 1). The presence, latency and amplitude of the individual BAEP components and variations of the stimulus artifact were evaluated. The mean ( ± S.D.) amplitude of the stimulus artifact was 0.26 ± 0.12 μV in the brain-dead subjects and 0.09 ± 0.05 μv in the control group ( P < 0.001, t test). The causes of the phenomenon of increasing stimulus artifacts in the evolution of brain death remain unclear.