MRI lesions in younger healthy adults

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Non-traumatic subarachnoid hemorrhage with normal angiogram. Long-term follow-up and CT predictors of complications

We investigated 91 patients with non-traumatic subarachnoid hemorrhage (SAH) in whom no aneurysm was found on initial angiography. In 31 of these patients CT did not show subarachnoid blood. A typical feature was a localized blood clot in the prepontine or interpeduncular cistern. Follow-up was obtained 6 months to 11.8 years after SAH by personal re-examination (n = 49) or questionnaire sent to patients or their doctors. 79 patients were free of neurological signs, 3 had a mild and one a severe neurological deficit. Five patients had died from SAH. Those patients who died or had complications often had blood in the frontal basal interhemispheric fissure. None of the 3 therapeutic regimens applied proved to be superior. We conclude that prognosis is good, but an unidentified aneurysm must be considered and repeat angiogram is warranted if blood is found in the anterior part of the basal cisterns. When the hemorrhage is in the prepontine cistern, repeat angiogram is not necessary.

Interhemispheric inhibition of the human motor cortex

1. Using two magnetic stimulators, we investigated the effect of a conditioning magnetic stimulus over the motor cortex of one hemisphere on the size of EMG responses evoked in the first dorsal interosseous (FDI) muscle by a magnetic test stimulus given over the opposite hemisphere. 2. A single conditioning shock to one hemisphere produced inhibition of the test response evoked from the opposite hemisphere when the conditioning-test interval was 5-6 ms or longer. We shall refer to this as interhemispheric inhibition. However, the minimum latency of inhibition observed using surface EMG responses may have underestimated the true interhemispheric conduction time. Single motor unit studies suggested values 4-7 ms longer than the minimum interval observed with surface EMG. 3. Interhemispheric inhibition was seen when the test muscle was active or relaxed. Increasing the intensity of the conditioning stimulus increased the duration of inhibition: increasing the intensity of the test stimulus reduced the depth of inhibition. 4. The conditioning coil had to be placed on the appropriate area of scalp for inhibition to occur. The effect of the conditioning stimulus was maximal when it was applied over the hand area of motor cortex, and decreased when the stimulus was moved medial or lateral to that point. 5. The inhibitory effect on the test stimulus probably occurred at the level of the cerebral cortex. In contrast to the inhibition of test responses evoked by magnetic test stimuli, test responses evoked in active FDI by a small anodal electric shock were not significantly inhibited by a contralateral magnetic conditioning stimulus. Similarly, H reflexes in relaxed forearm flexor muscles were unaffected by conditioning stimuli to the ipsilateral hemisphere. However, inhibition was observed if the experiment was repeated with the muscles active.

[Evoked potentials in diagnosis of ischemic brain stem lesions]

We present an overview on the impact of evoked potentials in diagnosis of ischemic brainstem lesions. Brainstem auditory evoked potentials and somatosensory evoked potentials depict abnormalities, whereas visual evoked potentials are normal in most cases. In patients with basilar artery thrombosis and primary pontine hemorrhage these evoked potentials are mostly abnormal and can indicate the location of the lesion. Furthermore, they are of prognostic value. Whether evoked potentials are abnormal in strokes with branch occlusion of the basilar artery, depends on the location of the infarction. In infarctions of the basis pontis BAEP and SEP may be normal. Hemiparesis in brainstem strokes are associated with abnormalities in transcranial magnetic stimulation. However, no further evaluation of the level of the pyramidal tract lesion is possible by this method. During fibrinolytic therapy of basilar artery thrombosis a continuous monitoring is possible by means of BAEP. Thus, information can be obtained that is not available from neurological examination of the patient under sedative drugs.

Microinfarction in classic migraine? A study with magnetic resonance imaging findings

By means of magnetic resonance imaging we investigated a total of 45 patients suffering from classic migraine; 25 patients had been treated in our department for classic migraine over the past 2 years (group A), and 20 other patients investigated between 1976 and 1984 were reexamined for this study (group B). Thirty-two age- and roughly sex-matched healthy volunteers underwent magnetic resonance imaging and served as controls (group C). There was a trend for patients with classic migraine to have more subcortical patchy lesions on T2-weighted magnetic resonance imaging. In a comparison of our control subjects and patients with a history of greater than 20 attacks of classic migraine taken from groups A and B, this difference in number of lesions was significant (p = 0.02). The results suggest that patchy lesions in patients with classic migraine should be interpreted with particular caution before diagnosing a demyelinating disease since the lesions could be ischemic in origin.

[Spinal and subcortical somatosensory evoked potentials: a comparison with the localization of spinal, medullary and pontine lesions and in brain death]

The spinal and subcortical median nerve SEPs were recorded in 65 patients with lesions of the cervical cord, medulla oblongata, pons and in brain death. A recording technique including cephalic, non-cephalic and anterior neck referenced leads was used. The location of the lesions corresponded to different types of SEP alterations: Cervical extramedullary lesions compressing the spinal cord corresponded to a prolonged P9-P14 interpeak latency. Cervical intramedullary lesions corresponded to the loss of N13, normally generated in the spinal interneurons. Vascular lesions of the medulla oblongata (Wallenberg's syndrome) showed normal SEPs. Space occupying medulla oblongata lesions corresponded to reduction in amplitude or loss of P14. Pontine lesions showed normal spinal and subcortical SEPs. In brain death P14 showed a graduate decrease in amplitude or alternatively vanished abruptly. The spinal and subcortical SEPs provide a good tool for testing the function of the lemniscal pathways and the spinal interneurons.

Intercostolumbar spinal nerve anastomosis. An experimental study in dogs

End-to-end anastomoses were done between the motor roots of T12 and T13 intercostal nerves and the ipsilateral transsected L1 lumbar nerve in four dogs. In three of the dogs, the clinical and electrophysiologic findings showed functional viability of the intercostolumbar anastomosis 3.5 months after the anastomosis was done. The method may be practical for reinnervating an injured lumbar nerve with two intercostal nerves or to bypass a spinal cord lesion.

Short-term memory performance with magnetic stimulation of the motor cortex

Whether transcranial magnetic stimulation of the motor cortex has an influence on memory was investigated. In a first experiment with 21 healthy volunteers six pronounceable nonsense words were visually presented, immediately followed by a magnetic stimulus. There were three blocks of stimulation with field intensities of 60, 80 and 100% (referring to a maximal intensity of 2 Tesla), each block comprising six magnetic stimuli and six nonsense words. After each block there was a free recall test and at the end another free recall trial as well as a multiple-choice recognition test for all 18 words. Eighteen subjects served as controls, undergoing the same procedure, except that the field intensity was zero. A significant but small reduction of short-term memory performance was observed only for 100% field intensity. In a second experiment with 16 subjects who had not participated in experiment I, the effect of 100% intensity cortical magnetic stimulation was compared with a control stimulation over the cervical spine. There was no difference in free recall or in the multiple-choice test between the sites of stimulation, suggesting that the difference in the 100% intensity block in experiment I was not due to a specific cortical effect of the magnetic field on memory function. With respect to the effect on memory functions, transcranial magnetic stimulation of the motor cortex is thought to be a safe method.

Hereditary motor and sensory neuropathy (HMSN) and optic atrophy (HMSN type VI, Vizioli)

Clinical and electrophysiological findings are described in three patients with hereditary motor and sensory neuropathy in association with optic atrophy (HMSN VI). The optic atrophy was of the Leber type in a 15-year-old boy. In a 70-year-old patient, as in three members of his family, optic atrophy was associated with tapetoretinal degeneration. In addition to HMSN and optic atrophy a 20-year-old man suffered from sensorineural deafness. Electrophysiological studies indicated a neuronal form of neuropathy, as in HMSN II. Brainstem auditory evoked potentials also revealed subclinical involvement of the central auditory pathways in the patients without hearing defects.

Clinical features of proven basilar artery occlusion

Our study describes the early symptoms and signs of 85 patients with either basilar artery occlusion or bilateral distal vertebral artery occlusion documented by selective angiography. The most common prodromal symptoms were vertigo, nausea, and headache, which occurred during the 2 weeks before the stroke. Angiographic findings of 49 patients were classified into proximal, middle, and distal basilar artery occlusions. Twenty-two of these patients had additional vertebral artery lesions. A fourth group was composed of 36 patients with bilateral distal vertebral artery occlusion without opacification of the basilar artery through a vertebral artery injection. Onset was sudden in 20 patients; sudden, but preceded by prodromal symptoms in 11 patients; and progressive in 54 patients. Patients with progressive strokes often had bilateral vertebral artery occlusions. Most patients with acute onset had occlusion of the middle and distal basilar artery. An embolic origin of basilar artery occlusion from an arteriosclerotic vertebral artery lesion was assumed to be an important mechanism. An embolus reaching the basilar artery may not necessarily reach the top of the artery, but may also become lodged more proximally.

Brainstem auditory evoked potentials and somatosensory evoked potentials in pontine haemorrhage. Correlations with clinical and CT findings

Electrophysiological studies were performed on 17 patients with pontine haemorrhage. Most had had massive hypertensive bleeding, leading to death in 12 of them within 3 months. Of the 5 surviving patients, 2 had a poor outcome and 3 a moderately good outcome. Brainstem auditory evoked potentials (BAEPs) and somatosensory evoked potentials (SEPs) were recorded in all patients, mostly with serial recordings. BAEPs were pathological in all patients. The most important finding was a reduction in amplitude or loss of waves. With a loss of waves after wave II bilaterally all patients died; the 2 patients with a normal amplitude of waves I-V at least on one side, survived in good condition. Further prognostic conclusions were not possible. The correlation with the clinical state was limited and was best for small unilateral tegmental haemorrhages. Eleven of the 17 patients suffered bilateral loss of the N20 component of the median nerve SEP. All these patients died. In patients with unilateral loss of the SEP the outcome could be favourable even if the bleeding extended across the midline. 'Subcortical' SEPs were not significantly altered. EEG findings in 15 and visual evoked potentials in 4 patients showed preserved forebrain electrical activity even in patients in poor condition.

Complex hyperkinesia during recovery from left temporoparietal cortical infarction

A 51-year-old man with preexistent lacunar infarctions in the basal ganglia and pons developed complex involuntary movements of his right arm 1 day after a purely cortical-subcortical ischemic infarction in the territory of the left middle cerebral artery sparing the basal ganglia. The movements were stereotyped and repetitive, affecting hand and fingers or proximal arm muscles alternatively or together. Although hyperkinesia after basal ganglia lesion has been described many times in the literature, it has not yet been reported after cortical-subcortical ischemic infarctions sparing the basal ganglia.

Loss of brainstem acoustic evoked potentials with spontaneous breathing in a patient with supratentorial lesion

The loss of brainstem acoustic evoked potentials (BAEP) is considered as a confirmatory test for the diagnosis of brain death in patients with supratentorial lesions. We report a patient with ischemia in the territory of the left middle and anterior cerebral artery, who showed a loss of BAEP waves III-V as a sign of brainstem compression, but maintained spontaneous breathing and EEG activities. We conclude that occasionally BAEP may provide misleading results in the diagnosis of brain death.

Putaminal haemorrhage after recanalization of an embolic MCA occlusion treated with tissue plasminogen activator

We present the case of a 42-year-old female, who suffered an embolic occlusion of the right middle cerebral artery (MCA). Recanalization was achieved with tissue plasminogen activator (t-PA) within 7 h after onset of stroke. Post-t-PA infusion angiographic and CT examinations revealed fragmentation of the thrombus and a small putaminal haemorrhage associated with early reperfusion of the MCA. No clinical deterioration was observed and complete recovery occurred within 10 days.

The complete apallic syndrome--a case report

In six patients with apallic syndrome the EEG was isoelectric, although the patients were breathing spontaneously and vegetative functions remained stable for a long period of time. No cortical somatosensory evoked potentials could be recorded in four of the patients examined. Cranial CT performed in three patients revealed extensive hypodensity of the cortex, whereas the brain stem showed no major damage. This syndrome is labelled a "complete apallic syndrome". None of our patients, and none of the 23 patients described in the literature, recovered.

Intra-arterial thrombolytic therapy improves outcome in patients with acute vertebrobasilar occlusive disease

In this retrospective analysis we report our treatment experience in 65 consecutive patients with clinical signs of severe brainstem ischemia with angiographically demonstrated thrombotic vertebrobasilar artery occlusions who received either local intra-arterial thrombolytic therapy (urokinase or streptokinase) (43 patients) or conventional therapy (antiplatelet agents or anticoagulants) (22 patients). We analyzed the data with respect to cerebral artery occlusion patterns, posttreatment arterial recanalization, and the clinical categories of favorable/unfavorable outcome and survival/death. In subgroup analyses, recanalization in patients who received thrombolytic therapy correlated significantly with clinical outcome; in 19 of 43 patients, recanalization was demonstrated angiographically, while in 24 patients the occlusion persisted. All patients without recanalization died, but 14 of the 19 patients displaying recanalization survived (p = 0.000007), 10 with a favorable clinical outcome. Only three of the 22 patients who received conventional therapy survived, all with a moderate clinical deficit. When we compared the treatment groups, highly significant differences in both outcome quality (p = 0.017) and survival (p = 0.0005) were found to depend on establishing recanalization. Our data support the concept that technically successful thrombolysis of vertebrobasilar artery occlusions is associated with beneficial clinical outcome.

Local intra-arterial fibrinolytic therapy in acute carotid territory stroke. A pilot study

The possibility that intra-arterial local infusion of fibrinolytic agents may achieve recanalization of previously occluded carotid territory arteries in acute stroke was tested in a prospective angiography-based open pilot study at two centers. Fifteen of 20 patients with acute symptoms (mean treatment-onset interval 7.6 hours) demonstrated complete recanalization; 10 of the 15 patients exhibited clinical improvement of varying degree by the time of hospital discharge. Four of the 20 patients suffered hemorrhagic transformation of the infarcted territory without clinical deterioration or demise. Because of the study format and the limited number of patients, dose responses for recanalization and risk relations were not established. We conclude that local intra-arterial fibrinolytic therapy may lead to cerebral arterial recanalization in acute carotid territory thrombotic stroke. The particular implications and limitations of this approach are discussed.

Combined SPECT imaging of regional cerebral blood flow (99mTc-hexamethyl-propyleneamine oxime, HMPAO) and blood volume (99mTc-RBC) to assess regional cerebral perfusion reserve in patients with cerebrovascular disease

In 53 patients with cerebrovascular disease (CVD), regional cerebral blood flow (CBF) and blood volume (CBV) were imaged by SPECT within one session. Slice division (CBF: CBV) yielded distribution of regional cerebral perfusion reserve (CPR). Semiquantitative evaluation was obtained from manually set ROIs by interhemispherical ratios (for CBF, CBV and CPR), using 2 SD from a normal group (n = 10) as a threshold. Sensitivities were 59% for CBF, 94% for CBV and 83% for CPR. Combined sensitivity was 98%. Establishing three constellations for CBF, CBV and CPR, regionally normal CBFs but quantitatively increased CBVs (+69%) and decreased CPRs (-31%) were found in relatively early stages of CVD. Very advanced cases showed decreased CBFs (-65%), CBVs (-40%), CPRs (-49%) and a surrounding penumbra. In 87% (46/53 patients), such rheologically postulated constellations could be demonstrated. We conclude that combined CBF and CBV SPECT, assisted by CPR images, is a promising tool to detect CVD and to assess its individual regional severity.

Evoked potentials in basilar artery thrombosis: correlation with clinical and angiographic findings

In 28 patients with vertebro-basilar or basilar artery thrombosis brain-stem auditory evoked potentials (BAEPs) and somatosensory evoked potentials (SEPs) have been recorded. Visual evoked potentials (VEPs) were recorded in 7 of these 28 patients. In 24 patients the diagnosis was angiographically proven and in 4 patients Doppler sonography and computerized tomography suggested this diagnosis. The BAEP and SEP findings were correlated to clinical and angiographical signs. BAEPs could be classified into 6 different patterns. In more than half of the patients different BAEP patterns from the two ears could be found. A pathological IV/V complex was most often found in comatose patients and in patients with a basilar artery occlusion distal to the anterior inferior cerebellar artery. Prolonged interpeak latency of I-III was mainly found in alert or drowsy patients with caudal occlusions. The frequent occurrence of a BAEP with only wave I preserved, or with no waves preserved, in patients with brain-stem functions suggests that BAEPs are not useful in the diagnosis of brain death when basilar artery thrombosis is suspected. SEPs were either absent bilaterally or else severely altered on one side in all comatose patients. In alert patients, including those with 'locked-in' syndrome, SEPs were never absent bilaterally. Increased N13-N20 interpeak latency was an uncommon finding in this series. There was no correlation between the SEP and the angiographically proven location of the occlusion. In the 'locked-in' syndrome both SEP and BAEP findings were non-uniform. Normal SEPs were sometimes found in combination with severely altered BAEPs, suggesting partial deafferentation. Since basilar artery thrombosis is now a treatable condition, early diagnosis and documentation of functional deficits moves into a more important clinical area than heretofore.

Serial recording of median nerve stimulated subcortical somatosensory evoked potentials (SEPs) in developing brain death

Subcortical somatosensory evoked potentials (SEPs) to median nerve stimulation were recorded serially in 35 patients during the evolution towards brain death and in brain death. Neuropathological alterations of the central nervous system down to the C1/C2 spinal cord segment in brain death are well known. SEP components supposed to be generated above this level should be lost in brain death, while components generated below should not be altered. Erb's point, scalp and neck potentials were recorded at C3/4, or over the spinous process C7, using an Fz reference. In 10 patients additional montages, including spinous process C2-Fz, a non-cephalic reference (Fz-contralateral shoulder) and a posterior to anterior neck montage (spinous process C7-jugulum) were used. The cephalic referenced N9 and N11 peaks remained unchanged until brain death. N9 and N11 decreased in parallel in amplitude and increased in latency after systemic effects like hypoxia or hypothermia occurred. The cephalic referenced 'N14' decreased in amplitude and increased in latency after the clinical brain death syndrome was observed, while N13 in the posterior to anterior neck montage remained unchanged. The alteration of 'N14' went parallel to the decrease of the P14 amplitude. The subcortical SEPs in the cephalic referenced lead are supposed to be a peak composed by a horizontally orientated dorsal horn generated N13 and a rostrally orientated P14 arising at the level of the foramen magnum. The deterioration of the non-cephalic referenced P14 and of its cephalic referenced reflection 'N14' seems to provide an additional objective criterion for the diagnosis of brain death.

Carotid endarterectomy: factors influencing perioperative complications

Early carotid surgery has been suggested to be an important cause of perioperative deterioration due to secondary haemorrhage into a recent brain infarction. It has also been suggested that the existence of preoperative neurological deficits may worsen the prognosis of surgical treatment in carotid disease. Neither of these observations could be confirmed; severe perioperative complications (5%) in this study of carotid endarterectomy were strongly related to the degree of carotid stenosis. This aspect of carotid surgery has not been previously studied. Even though technical difficulties may play an exaggerated role in a training hospital system, it is nevertheless necessary to assess the impact of surgical procedures of different extent when the "acceptable risk" for carotid surgery is calculated.

The subcortical generated somatosensory evoked potentials in non-cephalic, cephalic, and anterior neck referenced recordings in a patient with a cervico-medullary lesion: a clue to the identification of the P14/N14 and N13 generators

Median nerve somatosensory evoked potentials (SEPs) were studied in a patient before and after the development of a cervico-medullary lesion. The first examination demonstrated normal subcortical generated potentials N13 and N14. The second examination, following a subarachnoid haemorrhage at the cervico-medullary junction, displayed a delayed and reduced amplitude P14/N14 peak on both sides. P14/N14 showed the same latency in all montages, using non-cephalic, cephalic and anterior neck references. The N13 component was not significantly changed in latency compared with the first examination. The latencies of the N13 peak were variable in the different montages. They increased from the lower (C7) to the upper (C2) neck, whereas the latency of the N13 onset was identical in all montages. This alteration might be caused by a delayed near-field activity at C2 overlapping the N13 component. These results fit the hypothesis of two major generators responsible for subcortical SEPs; a near-field N13 component at the level of the lower neck and a far-field P14 component arising from the level of the cervico-medullary junction. An additional minor near-field activity generated by the cuneate nucleus is suspected.

"Distal stump" of the internal carotid artery with ascending pharyngeal artery collateralisation. A potential source for further embolic ischemia

In 2 patients, clinically exhibiting recent amaurosis fugax and small cortical infarction, carotid occlusion had been shown by means of doppler ultrasound. IA-DSA showed a collateral circulation within the distal carotid artery in the base of the skull via the ascending pharyngeal artery. The slowly perfused stump of a distal carotid artery is supposed to be a potential source of emboli into the retinal or intracranial territories.

[Validity of early acoustically-evoked potentials in the diagnosis of brain death]

Brainstem acoustic evoked potentials (BAEP) in clinically proven brain death are already described in the literature. In most cases there were no reproducable BAEP or only wave I ipsilateral. In a few cases, shortly after the onset of brain death, wave I and a wave II ipsilateral have been detected. 40 Patients were examined during developing brain death and in brain death. Using an ipsilateral and contralateral montage (mastoid/vertex) four different patterns of BAEP in brain death could be distinguished: Wave I ipsilateral and wave II ipsilateral, reduced in amplitude and delayed in latency and a wave I-contralateral, Wave I ipsilateral and wave I-contralateral, Only wave I ipsilateral, No reproducable BAEP. In clinically not brain dead patients, three different patterns of BAEP are recorded which should be known in order to comment on the validity of the method in the diagnosis of brain death: Only wave I and a flat and late wave, only recordable using several reproductions and with a low rate of artefacts. Only wave I recordable while the patient is still breathing spontaneously (false positive results). Reversible loss of wave I. Ignoring the results, the BAEP may lead to false positive results in the diagnosis of brain death.

[Electrophysiologic findings in lacunar infarcts]

Lacunar lesions are small infarctions in the territory of small penetrating arteries of the brain. Because of their small size these lesions can only in part be detected by CT. Clinical symptoms do not always correspond with the lesions visible in the CT. We studied the somatosensory evoked potentials (SEP), the visual evoked potentials (VEP) and the electrically elicited blink reflex in 50 patients with lacunes to determine if there are any other lesions which are not detectable by clinical examination or CT alone. While VEP and the blink reflex showed pathological results in only a few of these patients the SEP were pathological in about 75%. The multiplicity of the lesions may be documented by means of these investigations.

Isolated brain-stem death. Case report with demonstration of preserved visual evoked potentials (VEPs)

Brain-stem death is a state in which brain-stem functions have ceased whereas the hemispheres still have electrical activity. We report a patient with a haematoma over the cerebellum and the pons who showed a preserved electroencephalogram and VEPs whereas all clinical signs of cerebral death was present. Normal VEPs in isolated brain-stem death have not yet been reported. We conclude that in any case of infratentorial lesion, an electroencephalogram should be recorded for the diagnosis of brain death.

Remarks on the follow-up of cerebellar astrocytomas

A retrograde study was performed in 105 patients operated upon between 1950 and 1972 for a cerebellar astrocytoma. Complete histories were available for 89 patients. Forty-five patients died within the first 3 months after operation. Of the 32 patients who were still alive, 14 patients had been operated upon 20-30 years previously and 18 patients 10-19 years previously. Twelve patients died over 3 months after the operation; in 6 cases, recurrence of tumour was the cause of death. Of the 7 patients who were irradiated post-operatively, 5 died. In 26 patients the tumor had infiltrated the brain-stem and only 7 patients survived the operation. However, 2 patients are still alive after 25 and 10 years, respectively. The findings indicate that patients operated upon for a localized cerebellar astrocytoms can be considered cured and irradiation and chemotherapy are not warranted. When the tumour has infiltrated the brain-stem, a survival period of more than 20 years is possible after partial resection.

[Monitoring of therapeutic neuroradiologic examination and therapeutic procedures using evoked potentials]

Interventional neuroradiology makes use of different diagnostic and therapeutic catheterization techniques. Treatments performed are local intraarterial thrombolytic therapy, embolization and occlusion of brain supplying arteries, percutaneous transluminal angioplasty and intraarterial application of drugs. These treatments make it most important to check the patients neurological state during the procedure. Intraoperative monitoring of evoked potentials offers the opportunity to get objective information about changes in certain central nervous system functions even in anaesthesized patients. Usually intraoperative monitoring is performed to obtain information whether the function of structures at risk remains stable or is altered by the operation. This represents a more passive, observing way of monitoring. During interventional neuroradiology one is enabled to take additionally a more active and experimental way of monitoring by using the advantages of special catheter techniques like series of reversible balloon occlusion or intraarterial drug application. This leads to a dialogue between the radiologist and the neurophysiologist about the safety or the risk of the next step during a procedure. There are mainly two types of new information that can be achieved by active monitoring: the identification of functional territories of single or multiple feeding vessels and new insights into hemodynamics and the establishing of new sufficient collaterals. We have used intraoperative neuromonitoring in 35 patients during interventional neuroradiology. Our findings will be summarized and the usefulness of the different monitoring methods will be discussed.

A case of spinal paraganglioma

The neuroradiologic finding of a paraganglioma in the vertebral canal is described here for the first time. These tumors occur more frequently than was previously presumed. Similarities with paragangliomas in the craniocervical region are apparent on angiograms. We consider angiography to be indicated when, in association with a spinal tumor, urinary biogenic amine levels are elevated. When necessary, embolization can be performed after angiography.

Local intraarterial fibrinolytic therapy in inaccessible internal carotid occlusion

Two exemplary cases of upper carotid occlusion and successful local intraarterial fibrinolytic therapy are described. To achieve a positive result one has to perform a balloon occlusion of the affected internal carotid artery while applying the fibrinolytic agent. Possible time limits of instigating therapy are discussed especially if the lenticulostriatal arteries are additionally affected.