J. J. Marx

Observations on comatose survivors of cardiopulmonary resuscitation with generalized myoclonus

BackgroundThere is only limited data on improvements of critical medical care is resulting in a better outcome of comatose survivors of cardiopulmonary resuscitation (CPR) with generalized myoclonus. There is also a paucity of data on the temporal dynamics of electroenephalographic (EEG) abnormalities in these patients.MethodsSerial EEG examinations were done in 50 comatose survivors of CPR with generalized myoclonus seen over an 8 years period.ResultsGeneralized myoclonus occurred within 24 hours after CPR. It was associated with burst-suppression EEG (n = 42), continuous generalized epileptiform discharges (n = 5), alpha-coma-EEG (n = 52), and low amplitude (10 μV <) recording (n = 1). Except in 3 patients, these EEG-patterns were followed by another of these always nonreactive patterns within one day, mainly alpha-coma-EEG (n = 10) and continuous generalized epileptiform discharges (n = 9). Serial recordings disclosed a variety of EEG-sequences composed of these EEG-patterns, finally leading to isoelectric or flat recordings. Forty-five patients died within 2 weeks, 5 patients survived and remained in a permanent vegetative state.ConclusionGeneralized myoclonus in comatose survivors of CPR still implies a poor outcome despite advances in critical care medicine. Anticonvulsive drugs are usually ineffective. All postanoxic EEG-patterns are transient and followed by a variety of EEG sequences composed of different EEG patterns, each of which is recognized as an unfavourable sign. Different EEG-patterns in anoxic encephalopathy may reflect different forms of neocortical dysfunction, which occur at different stages of a dynamic process finally leading to severe neuronal loss.

Long term follow up after percutaneous closure of PFO in 357 patients with paradoxical embolism: Difference in occlusion systems and influence of atrial septum aneurysm

BACKGROUND Percutaneous transcatheter closure of patent foramen ovale (PFO) in cryptogenic stroke or TIA is an alternative to medical therapy especially in patients with atrial septal aneurysm (ASA). The differences in time to complete occlusion for various closure devices in PFO alone and PFO plus ASA are of natural interest. METHODS AND RESULTS Between January, 1st 1998 and November, 30th 2006 percutaneous PFO closure was performed in 357 patients with a history of > or =1 paradoxical embolism using three different devices: Amplatzer PFO-(n=199), Starflex-(n=48) and Helex Occluder (n=110). All patients were assigned to a post-interventional protocol with contrast-enhanced transesophageal echocardiography (TOE) at 1 and 6 months and every 6 to 12 months in case of incomplete closure. Definite closure was confirmed in at least two consecutive TOE studies. The closure time curves between the three devices were significantly different (p=0.0072). Devices of 25 mm or less had a better occlusion rate. The difference between the closure time curves of PFO and PFO+ASA concerning each device type was significant for Helex (p=0.006) and Starflex (p=0.030). In regard to the occlusion time for large devices Helex succeeded later than Amplatzer and Starflex (p=0.0029). Concerning the cumulative follow up period of 1265 patient years the recurrence/re-event rate of cerebral and peripheral thromboembolic events was 0.7% per patient year. No relation to residual PFO shunting or to thrombus formation was seen. There were no peri-interventional technical complications. In five patients of the Starflex group thrombi were detected in the four week TOE controls. CONCLUSION The closure rate is dependent on occluder size and type plus the occurrence of an atrial septum aneurysm.

Mechanisms and predictors of chronic facial pain in lateral medullary infarction.

The purpose of this study was to identify clinical predictors and anatomical structures involved in patients with pain after dorsolateral medullary infarction. Eight out of 12 patients (67%) developed poststroke pain within 12 days to 24 months after infarction. The pain occurred in the ipsilateral face (6 patients) and/or the contralateral limbs and trunk (5 patients, 3 of whom also had facial pain). Ipsilateral facial pain was significantly correlated with lower medullary lesions, including those of the spinal trigeminal tract and/or nucleus, as documented by magnetic resonance imaging. The R2 blink reflex component was abnormal only in patients with facial pain. Likewise, pain and temperature sensation in the ipsilateral face was decreased in all patients with facial pain but not in patients without pain. Ipsilateral touch sensation in the face was also decreased in all patients with facial pain, but the lesions revealed on magnetic resonance imaging did not involve the principal sensory nucleus of the fifth cranial nerve, and the R1 blink reflex latencies were normal. Although facial pain was correlated with lesions of the spinal trigeminal tract and/or nucleus, none of the lesions involved the subnucleus caudalis, which contains most nociceptive neurons. These findings suggest that facial pain after medullary infarction is due to lesions of the lower spinal trigeminal tract (axons of primary afferent neurons), leading to deafferentation of spinal trigeminal nucleus neurons. Ann Neurol 2001;49:493–500

Diffusion weighted magnetic resonance imaging in the diagnosis of reversible ischaemic deficits of the brainstem

Objectives: To evaluate the sensitivity of diffusion weighted magnetic resonance imaging (MRI) for the diagnosis of clinically suspected reversible ischaemic deficits of the brainstem. Methods: A total of 158 consecutive patients presenting with acute signs of brainstem dysfunction were investigated using EPI diffusion weighted MRI within 24 hours of the onset of symptoms. High resolution T1 and T2 weighted imaging was performed as a follow up after a median of six days Results: Fourteen of the 158 patients had a complete clinical recovery within 24 hours (transitory ischaemic attack (TIA)), and 19 patients recovered in less than one week (prolonged reversible neurological deficit (RIND)). Diffusion weighted MRI showed acute ischaemic deficits in 39% of patients with transient neurological deficits. The detection rate seemed to be higher in patients with longer lasting symptoms, but the difference between patients with TIA (29%) and RIND (47%) was not significant. Conclusions: Diffusion weighted MRI is a sensitive indicator of acute ischaemic brainstem deficits even in patients with reversible neurological deficit. Early identification of patients with TIA and increased risk of stroke may influence acute management and improve patient outcome.

A topodiagnostic investigation on body lateropulsion in medullary infarcts

Body lateropulsion may occur without signs of vestibular dysfunction and vestibular nucleus involvement. The authors examined 10 such patients with three-dimensional brainstem mapping. Body lateropulsion without limb ataxia reflected an impairment of vestibulospinal postural control caused by a lesion of the descending lateral vestibulospinal tract, whereas body lateropulsion with limb ataxia was probably the consequence of impaired or absent proprioceptive information caused by a lesion of the ascending dorsal spino-cerebellar tract.

Isolated voluntary facial paresis due to pontine ischemia

We describe a patient withpatientwith isolated voluntary facial paresis due to a unilateral lacunar lesion in the contralateral mediodorsal middle base of the pons. Transcranial magnetic stimulation confirmed the involvement of supranuclear corticofacial tract fibers and sparing of the corticolin-gual and corticospinal connections. This observation demonstrates that the fibers conveying voluntary orofacial activation descend mediodorsally at the level of the middle pons and that the fibers conveying emotional activation may be assumed to converge below this level.

Blink reflex R2 changes and localisation of lesions in the lower brainstem (Wallenberg’s syndrome): an electrophysiological and MRI study

OBJECTIVES Pathways of late blink reflexes are detected by high resolution MRI. Electronically matched stroke lesions superimposed to an anatomical atlas show the suspected course. METHODS Fifteen patients with infarction of the lower brainstem, MRI lesions and electrically elicited blink reflexes were examined. The involved structures in patients with R2 and R2c blink reflex changes were identified by biplane high resolution MRI with individual slices matched to an anatomical atlas at 10 different levels using digital postprocessing methods. RESULTS The blink reflexes were normal in five of 15 patients (33%) and showed loss or delay of R2 and R2c to stimulation ipsilaterally to lesion (R2-i and R2c-i) in eight (53%). Loss or delay of R2-i/R2c-i was seen in lesions covering the entire trigeminal spinal tract and nucleus (TSTN) at at least one level. These infarctions were located more dorsally within the medulla. Patients with normal blink reflexes showed lesions sparing or involving the TSTN only partially. They more often had incomplete Wallenberg’s syndromes and MRI lesions were located more ventrally. CONCLUSIONS Using digital postprocessing MRI methods it was possible to identify central pathways of late blink reflex in patients with Wallenberg’s syndrome. This method is suggested as a new approach to identify incompletely understood functional structures of the brainstem.

Therapy of Early Poststroke Depression With Venlafaxine: Safety, Tolerability, and Efficacy as Determined in an Open, Uncontrolled Clinical Trial

To the Editor: The development of persistent depressive symptoms is a severe and frequent complication of ischemic or hemorrhagic stroke.1 The etiology of poststroke depression is not well understood. Only few placebo-controlled, double-blind studies have been carried out, all reporting various degrees of superiority of standard antidepressants over placebos.1 2 On the other hand, serious side effects have been reported.3 4 In most of these studies, patients were examined whose stroke had occurred several weeks to several months before the antidepressive therapy was started. Antidepressive therapy in the first weeks after stroke has not yet been attempted in studies. Drug-induced improvement of neurotransmission, in particular adrenergic transmission, facilitates recovery in animal brain trauma and stroke models.5 Antidepressants enhance neurotransmission by blockade of serotonergic and/or adrenergic reuptake transporters, by blocking the enzymatic degradation of monoamines or by other mechanisms, such as the blockade of presynaptic adrenergic receptors. Therefore, the treatment with antidepressants might in some cases exert a favorable effect on functional recovery independent of the psychopathological state.6 We report data on the safety, tolerability, and efficacy of venlafaxine in patients suffering from acute poststroke depression. Venlafaxine was chosen because of its relatively good tolerability compared …

Topodiagnostic implications of hemiataxia: An MRI-based brainstem mapping analysis

The topodiagnostic implications of hemiataxia following lesions of the human brainstem are only incompletely understood. We performed a voxel-based statistical analysis of lesions documented on standardised MRI in 49 prospectively recruited patients with acute hemiataxia due to isolated unilateral brainstem infarction. For statistical analysis individual MRI lesions were normalised and imported in a three-dimensional voxel-based anatomical model of the human brainstem. Statistical analysis revealed hemiataxia to be associated with lesions of three distinct brainstem areas. The strongest correlation referred to ipsilateral rostral and dorsolateral medullary infarcts affecting the inferior cerebellar peduncle, and the dorsal and ventral spinocerebellar tracts. Secondly, lesions of the ventral pontine base resulted in contralateral limb ataxia, especially when ataxia was accompanied by motor hemiparesis. In patients with bilateral hemiataxia, lesions were located in a paramedian region between the upper pons and lower midbrain, involving the decussation of dentato-rubro-thalamic tracts. We conclude that ataxia following brainstem infarction may reflect three different pathophysiological mechanisms. (1) Ipsilateral hemiataxia following dorsolateral medullary infarctions results from a lesion of the dorsal spinocerebellar tract and the inferior cerebellar peduncle conveying afferent information from the ipsilateral arm and leg. (2) Pontine lesions cause contralateral and not bilateral ataxia presumably due to major damage to the descending corticopontine projections and pontine base nuclei, while already crossed pontocerebellar fibres are not completely interrupted. (3) Finally, bilateral ataxia probably reflects a lesion of cerebellar outflow on a central, rostral pontomesencephalic level.

Emotional facial paresis of pontine origin

H.C. Hopf, MD, C. Fitzek, MD, J. Marx, MD, P.P. Urban, MD, F. Thomke, MD, Mainz, Germany A 63-year-old patient noticed sudden ataxic stance and gait dysarthria. Transitory symptoms were vertigo, nausea, and horizontal diplopia. Examination showed central Horner’s syndrome, impaired sweating of the face, hemiataxia, and moderate positional tremor on the right and facial paresis with emotional innervation only (figure, A and B) and impaired …