Darstellung der Zentralregion mit anisotroper echoplanarer Diffusionswichtung (EPI-DWI)

Im Rahmen dieser Studie sollte untersucht werden, ob sich eine diffusionsgewichtete Sequenz eignet, unter Ausnutzung der anisotropen Diffusionsverhaltnisse entlang der Markfasern die Zentralregion (ZR) bei Probanden und Patienten verlasslich darzustellen. Funf Patienten mit Hirntumoren und 20 gesunde Probanden wurden an einem klinischen 1,5-TMR-Tomographen untersucht. Bei den Probanden dienten die „klassischen“ anatomischen Zeichen zur Lokalisation der Zentralregion an einem 3-D-T1-Datensatz als Goldstandard zur Lokalisation, bei den Patienten zusatzlich noch ein funktionelles Magnet-resonanztomogramm (fMRT) mit einem Finger-Tapping-Paradigma im Blockdesign und der intraoperative Befund. Be…

Electrophysiological brainstem testing in the diagnosis of reversible brainstem ischemia.

The aim of this study was to evaluate the sensitivity of multimodal electrophysiological brainstem testing in the diagnosis of clinically suspected reversible ischemic deficits of the brainstem compared with diffusion weighted MR imaging. We investigated 158 consecutive patients presenting with signs of acute brainstem dysfunction. Serial electrophysiological brainstem tests including masseter reflex, blink reflex, masseter inhibitory reflex, AEP, MEP, EOG and the oculoauricular phenomenon were applied. In 14 of the 158 patients neurological deficits resolved in less than 24 hours, which was suggestive of a transitory ischemic attack (TIA), 19 patients had brainstem signs for more than 24 h…

Dysarthria in acute ischemic stroke: lesion topography, clinicoradiologic correlation, and etiology.

Background and purpose: Although dysarthria is a frequent symptom in cerebral ischemia, there is little information on its anatomic specificity, spectrum of associated clinical characteristics, and etiologic mechanisms. Methods: An investigation of 68 consecutive patients with sudden onset of dysarthria due to a single infarction confirmed by MRI or CT was conducted. Results: Dysarthria was associated with a classic lacunar stroke syndrome in 52.9% of patients. Isolated dysarthria and dysarthria–central facial and lingual paresis occurred in 2.9% (n = 2) and 10.3% (n = 7), respectively. Dysarthria–clumsy hand syndrome was observed in 11.7% (n = 8) of patients and associated with pure motor …

L�sionsverteilung von Hirnstamminfarkten im MRT

Seit langer Zeit sind typische Hirnstammsyndrome bekannt. Eines der haufigsten ist das Wallenberg- Syndrom bei dorsolateralem Medulla-oblongata-Infarkt. Ursache ist hier meist ein Verschluss der ipsilateralen PICA. Die Vielzahl der Syndrome auf der einen Seite sowie die Klassifikation der Hirnstamminfarkte in Gruppen andererseits konnen als Hinweis darauf angesehen werden, dass die Hirnstamminfarkte regelmasig bestimmte Territorien und Gebiete bevorzugen. Inwieweit diese Hypothese zutrifft, sollte an einem Patientenklientel mit akuten Hirnstamminfarkten untersucht werden. Ziel unserer Arbeit war die Darstellung typischer Lasionsverteilungen bei Patienten mit akutem Hirnstamminfarkt. Bei 117…

Abolished laser-evoked potentials and normal blink reflex in midlateral medullary infarction.

We investigated two patients presenting with the rare finding of almost isolated hemianalgesia with a sensory level on the contralateral side sparing the face. Clinical findings, electrophysiological studies (absent laser-evoked pain-related somatosensory potentials, normal electrically evoked somatosensory potentials, magnetically evoked potentials, and blink reflexes), and magnetic resonance imaging showed the ventrolateral medullar tegmentum containing the spinothalamic tract to be affected by lacunar infarction. The blink reflex R2 component was unimpaired in both patients.

A new method to investigate brain stem structural-functional correlations using digital post-processing MRI - reliability in ischemic internuclear ophthalmoplegia

We investigated the reliability of a new digital post-processing magnetic resonance imaging (MRI) technique in ischemic brain stem lesions to identify relations of the lesion to anatomical brain stem structures. The target was a medial longitudinal fasciculus (MLF) lesion, which was evident from ipsilateral internuclear ophthalmoplegia (INO). Sixteen patients with acute unilateral INO and an isolated acute brain stem lesion in T2- and EPI-diffusion weighted MRI within 2 days after the onset of symptoms were studied. The MRI slice direction was parallel and perpendicular to a slice selection of a stereotactic anatomical atlas. The individual slices were normalized and projected in the digita…

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-…

Symmetrical Infarction of the Cervical Spinal Cord Due to Spontaneous Bilateral Vertebral Artery Dissection

To the Editor: Vertebral artery (VA) dissection is a well-known cause of vertebrobasilar ischemia in young people and may be due to preceding chiropractic maneuvers, cystic medial necrosis, mucopolysaccharidosis and reticular fiber diseases, vasculitis,1 2 or a yet-unknown arteriopathy.3 Common findings in VA dissection are unilateral or bilateral neck pain associated with cerebellar and brain stem (usually medullary) infarctions,2 3 which are rarely associated with clinical signs of spinal cord lesions.4 5 6 Recently, 1 patient each was described with bilateral spinal cord infarction7 and Brown-Sequard’s syndrome8 as the sole manifestation of spontaneous unilateral VA dissection. We add an…

Topodiagnostik ischämisch bedingter Dysarthrophonien

In einer prospektiven Studie untersuchetn wir 106 konsekutiv eingeschlossene Patienten mit apoplektiform auftretender Dysarthrophonie aufgrund eines im MRT gesicherten singluaren, nicht raumfordernden Infarkts.

Bilateral Wallerian degeneration of the medial cerebellar peduncles after ponto-mesencephalic infarction

Three patients with acute large paramedian ponto-mesencephalic infarctions developed a bilateral retrograde degeneration of the medial cerebellar peduncles within 4 months after the insult. In an initial magnetic resonance imaging (MRI) within the first 2 weeks, the medial cerebellar peduncles showed normal intensities, but a control MRI after 4 months showed bright hyperintensities in the T2-TSE weighted images, and moderately increased signal intensities in echo planar imaging-diffusion weighted imaging were seen, possibly representing bilateral Wallerian degeneration of the cerebellar-pontine fibers.

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)). …

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.

Vasculitic wallenberg syndrome with detection of anti-proteinase 3 antibodies in the cerebrospinal fluid of a patient with severe Wegener's granulomatosis and only mild kidney involvement.

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 temper…

Time course of lesion development in patients with acute brain stem infarction and correlation with NIHSS score.

diffusion weighted magnetic resonance imaging (MRI) is highly sensitive in detecting acute supratentorial cerebral ischemia and Diffusion Weighted Imaging (DWI) lesion size has been shown to correlate strongly with the neurologic deficit in middle cerebral artery territory stroke. However, data concerning infratentorial strokes are rare. We examined the size and evolution of acute brain stem ischemic lesions and their relationship to neurological outcome.brain stem infarctions of 11 patients were analyzed. We performed DWI in all patients and in 7/11 patients within 24 h, T2W sequences within the first 2 weeks (10/11 patients) and follow-up MRI (MR2) within 3-9 months (median 4.8 months) la…

Ipsilateral facial weakness in upper medullary infarction-supranuclear or infranuclear origin?

We describe two patients with upper medullary infarctions showing ipsilateral facial weakness and relative sparing of the upper facial muscles. Electrophysiological follow-up using transcranial magnetic stimulation of the motor cortex in combination with stimulation of the peripheral facial nerve disclosed a supranuclear (corticofacial) tract lesion in one patient and a partial nuclear/infranuclear intra-axial facial nerve lesion in another.

Chapter 15 Pain and itch in Wallenberg's syndrome: anatomical–functional correlations

Publisher Summary The Wallenberg syndrome or dorso-lateral medullary infarction is the most common vascular syndrome of the medulla oblongata. Its clinical features include an ipsilateral Horner's syndrome, an ipsilateral limb ataxia, and mostly an ipsilateral but sometimes also a contralateral or bilateral decrease of pain and temperature sensibility of the face. Patients with Wallenberg's syndrome and with morphological (lesion) or functional (ipsilateral sensory deficit and delayed late blink reflex responses) show evidence of damage to the trigeminal tract and nucleus with sparing of the nucleus caudalis would develop facial pain. The trigeminal trophic syndrome (TTS), a very rare compl…

Diffusion-weighted MRI of cholesteatomas of the petrous bone

Purpose To investigate if primary cholesteatomas of the petrous bone show high signal in diffusion-weighted imaging (DWI). Materials and methods In this blinded study, we compared 15 patients with clinically certain cases and later surgically proven cholesteatomas vs. 12 patients with clinically acute otitis of the middle ear and 20 volunteers without petrous bone disease. Two blinded readers without knowledge of the clinical data decided in consensus agreement whether there was a pathologic signal increase in the petrous bone in an anisotropic single-shot echo-planar imaging (EPI) DWI sequence, an artifact, or no signal increase. Results Thirteen of 15 patients with cholesteatomas showed b…

Topodiagnostic value of blink reflex R1 changes: a digital postprocessing MRI correlation study.

The aim of the study was to investigate the relation of the blink reflex R1 arc to known anatomical brainstem structures. Acute vascular brainstem lesions as identified by magnetic resonance imaging (MRI) of patients with isolated R1 pathology were superimposed into a stereotactic anatomical atlas using a new method of digital postprocessing. Isolated acute brainstem lesions were documented by diffusion-weighted MRI in 12 of 24 patients with unilateral R1 pathology. The lesions were located in the ipsilateral mid- to lower pons. In three patients only, the lesion had partial contact with the principal sensory nucleus of the trigeminal nerve (PSN) on at least one level. In two patients, the …