Thomas Pfefferkorn

Technische Universität München, München, Bavaria, Germany

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Publications (98)294.41 Total impact

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    ABSTRACT: Symptoms of acute mountain sickness (AMS) may appear above 2,500 m altitude, if the time allowed for acclimatization is insufficient. As the mechanisms underlying brain adaptation to the hypobaric hypoxic environment are not fully understood, a prospective study was performed investigating neurophysiological changes by means of near infrared spectroscopy, electroencephalograpy (EEG), and transcranial doppler sonography at 100, 3,440 and 5,050 m above sea level in the Khumbu Himal, Nepal. Fourteen of the 26 mountaineers reaching 5,050 m altitude developed symptoms of AMS between 3,440 and 5,050 m altitude (Lake-Louise Score ⩾3). Their EEG frontal beta activity and occipital alpha activity increased between 100 and 3,440 m altitude, i.e., before symptoms appeared. Cerebral blood flow velocity (CBFV) in the anterior and middle cerebral arteries (MCAs) increased in all mountaineers between 100 and 3,440 m altitude. During further ascent to 5,050 m altitude, mountaineers with AMS developed a further increase in CBFV in the MCA, whereas in all mountaineers CBFV decreased continuously with increasing altitude in the posterior cerebral arteries. These results indicate that hypobaric hypoxia causes different regional changes in CBFV despite similar electrophysiological changes.Journal of Cerebral Blood Flow & Metabolism advance online publication, 17 June 2015; doi:10.1038/jcbfm.2015.142.
    Full-text · Article · Jun 2015 · Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism

  • No preview · Article · Nov 2014 · Journal of Infection
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    ABSTRACT: BACKGROUND AND PURPOSE: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-APECTS) applied to CT angiography source images (CTA-SI) predicts the functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). We assessed the diagnostic and prognostic impact of pc-ASPECTS applied to perfusion CT (CTP) in the BASICS registry population. METHODS: We applied pc-ASPECTS to CTA-SI and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) parameter maps of BASICS patients with CTA and CTP studies performed. Hypoattenuation on CTA-SI, relative reduction in CBV or CBF, or relative increase in MTT were rated as abnormal. RESULTS: CTA and CTP were available in 27/592 BASICS patients (4.6%). The proportion of patients with any perfusion abnormality was highest for MTT (93%; 95% confidence interval [CI], 76%-99%), compared with 78% (58%-91%) for CTA-SI and CBF, and 46% (27%-67%) for CBV (P < .001). All 3 patients with a CBV pc-ASPECTS < 8 compared to 6/23 patients with a CBV pc-ASPECTS ≥ 8 had died at 1 month (RR 3.8; 95% CI, 1.9-7.6). CONCLUSION: CTP was performed in a minority of the BASICS registry population. Perfusion disturbances in the posterior circulation were most pronounced on MTT parameter maps. CBV pc-ASPECTS < 8 may indicate patients with high case fatality.
    Full-text · Article · Jun 2014 · Journal of Neuroimaging
  • Konstantinos Dimitriadis · Thomas Pfefferkorn · Soheyl Noachtar
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    ABSTRACT: Depression as well as fear, joy and anger have been described as the semiological features of focal epileptic seizures. When emotions present as the sole symptoms of epileptic seizures, they may easily be misdiagnosed as a psychiatric disorder. We describe a patient with affective focal status epilepticus, secondary to limbic encephalitis, in which depression was the only clinical manifestation. Through EEG correlates the epileptic nature of depression could be proven. Furthermore, we discuss the association between epilepsy and depression, as well as the link between ictal depression and suicidal rates.
    No preview · Article · May 2014 · Case Reports
  • E Coppenrath · O Lenz · N Lummel · J Linn · F Bamberg · MF Reiser · M Dichgans · T Pfefferkorn · T Saam

    No preview · Article · Apr 2014 · RöFo - Fortschritte auf dem Gebiet der R
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    ABSTRACT: Multiple endovascular devices have been used for mechanical thrombectomy (MT) in basilar artery occlusion (BAO) for >10 years. Based on a single-center experience during the course of one decade, we present data on safety and efficacy of previous MT devices compared with modern stent retriever and suction thrombectomy. Eighty-one patients (29 women, 52 men, mean age 61.5 years, range 17-90) with angiographically confirmed BAO that had been treated by MT between 2001 and 2011 were retrospectively evaluated. Patients in group 1 (n = 60) had been treated between 2001 and 2008 with different devices available at that time. Patients in group 2 (n = 21) had been treated by modern stent retriever or local suction devices between 2008 and 2011. Recanalization rate, needle to recanalization time, procedure-related complications, and distal embolization of thrombotic material were recorded and compared. Recanalization rates of 95 % were high in both groups. Procedure-related dissection (n = 5) and subarachnoid hemorrhage (n = 9) occurred in group 1 but not in group 2 (p < 0.016). Needle-to-recanalization time was less than half in group 2 compared with group 1 (54.6 vs. 132.3 min, p < 0.01). Frequency of distal embolization was comparable in both groups (47 %). High recanalization rates have been achieved since the introduction of MT in BAO. However, modern stent retriever and suction devices allow for safer and more rapid recanalization compared with previous MT devices.
    No preview · Article · Jan 2014 · CardioVascular and Interventional Radiology
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    ABSTRACT: Our objectives were to evaluate rehabilitation outcome of aSAH survivors with severe disorders of consciousness (DOC) and to examine potential predictors of long-term outcome. Severe DOC includes patients in a vegetative state (VS) and in a minimally conscious state (MCS). This is a retrospective single-center cohort study of consecutive aSAH patients with severe and prolonged DOC upon admission to neurorehabilitation. Clinical assessments started right after discharge from ICU, a median of 26 days after the aSAH. Two different outcome criteria were used, one addressing the functional aspect (assessed by the Functional Independence Measure [FIM]) the other one addressing the level of consciousness ("behavioral outcome", assessed by the Coma Remission Scale [CRS]). Improved outcome was defined by an increase in FIM scores of at least 22 points (minimal clinically important difference) or by reaching a full score of 24 points on the CRS. Separate least square linear regression models were calculated to examine potential predictors for functional and behavioral outcome. Out of 63 patients, 19.0% and 39.7% of the patients achieved an improved functional and behavioral outcome, respectively. Age and level of consciousness upon admission to neurorehabilitation were independent prognostic factors for both outcome definitions. Both groups reached the better outcome category after a median of 11 and 9 weeks, respectively. In an individual patient, the longest delay to achievement of improved functional outcome was 30 weeks and to favorable behavioral outcome was 22 weeks after rehabilitation admission. About one-third of severely affected aSAH patients with DOC regained at least a favorable behavioral status during early neurorehabilitation. It is interesting to note that in our study population, the beginning of clinical improvement took up to 6 months after aSAH.
    Full-text · Article · Aug 2013 · Clinical neurology and neurosurgery
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    ABSTRACT: Background and purpose: Following mechanical recanalization of an acute intracranial vessel occlusion, hyperattenuated lesions are frequently found on postinterventional cranial CT. They represent either blood or-more frequently-enhancement of contrast agent. Here, we aimed to evaluate the prognostic value of these hyperattenuated intracerebral lesions. Materials and methods: One hundred one consecutive patients with acute stroke in the anterior circulation who underwent mechanical recanalization were included. Risk factors for hyperattenuated intracerebral lesions were assessed, and lesion volume was compared with the volume of final infarction. Clinical outcome and relative risk of secondary hemorrhage were determined in patients with and without any hyperattenuated lesions and compared. Results: The frequency of hyperattenuated lesions was 84.2%. Risk factors for hyperattenuated lesions were female sex, higher NIHSS score on admission, and higher amount of contrast agent applied. On follow-up, 3 patients showed no infarction; 53 patients, an ischemic infarction; and 45 patients, a hemorrhagic infarction. In all except 1 case, final volume of infarction (median = 92.4 mL) exceeded the volume of hyperattenuated intracerebral lesions (median = 5.6 mL). Patients with hyperattenuated lesions were at a 4 times higher relative risk for hemorrhagic transformation but had no significantly worse clinical outcome. Conclusions: Our data show that the extent of postinterventional hyperattenuated intracerebral lesions underestimates the volume of final infarction. Although hyperattenuated lesions indicate a higher risk of secondary hemorrhagic transformation, their presence seems not to be of any prognostic value regarding clinical outcome.
    Preview · Article · Aug 2013 · American Journal of Neuroradiology
  • E M Coppenrath · N Lummel · J Linn · O Lenz · M Habs · K Nikolaou · M F Reiser · M Dichgans · T Pfefferkorn · T Saam
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    ABSTRACT: OBJECTIVES: To compare the use of an unenhanced high-resolution time-of-flight MR angiography sequence (Hr-TOF MRA) with fat-suppressed axial/coronal T1-weighted images and contrast-enhanced angiography (standard MRI) for the diagnosis of cervical artery dissection (cDISS). METHODS: Twenty consecutive patients (9 women, 11 men, aged 24-66 years) with proven cDISS on standard MRI underwent Hr-TOF MRA at 3.0 T using dedicated surface coils. Sensitivity (SE), specificity (SP), positive and negative predictive values (PPV, NPV), Cohen's kappa (к) and accuracy of Hr-TOF MRA were calculated using the standard protocol as the gold standard. Image quality and diagnostic confidence were assessed on a four-point scale. RESULTS: Image quality was rated better for standard MRI (P = 0.02), whereas diagnostic confidence did not differ significantly (P = 0.27). There was good agreement between Hr-TOF images and the standard protocol for the presence/absence of cDISS, with к = 0.95 for reader 1 and к = 0.89 for reader 2 (P < 0.001). This resulted in SE, SP, PPV, NPV and accuracy of 97 %, 98 %, 97 %, 98 % and 97 % for reader 1 and 93 %, 96 %, 93 %, 96 % and 95 % for reader 2. CONCLUSIONS: Hr-TOF MRA can be used to diagnose cDISS with excellent agreement compared with the standard protocol. This might be useful in patients with renal insufficiency or if contrast-enhanced MR angiography is of insufficient image quality. KEY POINTS: • New magnetic resonance angiography sequences are increasingly used for vertebral artery assessment. • A high-resolution time-of-flight sequence allows the diagnosis of cervical artery dissection. • This technique allows the diagnosis without intravenous contrast medium. • It could help in renal insufficiency or when contrast-enhanced MRA fails.
    No preview · Article · Jun 2013 · European Radiology
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    ABSTRACT: Abstract Primary objective: Decompressive craniectomy is an effective therapy to relieve intractable intracranial hypertension following acute brain injury. However, little is known about the optimal timing for cranioplasties in the sub-acute phase. The objective of the present study was to analyse the effect of cranioplasty timing on neurological outcomes. Research design: Single-centre observational study. Methods and procedures: One hundred and forty-seven consecutive patients with decompressive craniectomy and cranioplasty during the course of inpatient neurorehabilitation were identified by means of a retrospective hospital database search. This database contains the following prospectively-entered weekly scores: Barthel-Index (BI), Functional Independence Measure (FIM) and Coma Remission Scale (CRS). Additional clinical data were taken retrospectively from patient charts. Regression analysis was used to identify factors that influenced the end-of-rehabilitation outcome. Main outcomes and results: Patients with shorter delays to cranioplasty (<86 days) had a better functional outcome than patients with longer delays of >85 days (60 ± 29.5 versus 25 ± 24.1 BI points; p < 0.01, respectively). Age, pre-operative BI and CRS scores were additional independent outcome factors. Complication rates were not different between early and late cranioplasty groups. Conclusions: Patients with decompressive craniectomy for management of intracranial hypertension may benefit from early cranioplasty.
    Full-text · Article · May 2013 · Brain Injury

  • No preview · Article · Apr 2013 · RöFo - Fortschritte auf dem Gebiet der R
  • E Coppenrath · N Lummel · J Linn · O Lenz · M Habs · K Nikolaou · MF Reiser · M Dichgans · T Pfefferkorn · T Saam

    No preview · Article · Apr 2013 · RöFo - Fortschritte auf dem Gebiet der R
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    ABSTRACT: The number of elderly patients with aneurysmal subarachnoid hemorrhage (SAH) is increasing with the aging of the population. However, management recommendations based on long-term outcome data and analyses of prognostic factors are scarce. Our study focused exclusively on elderly patients aged ≥60 years at the onset of SAH. Patients were selected from an in-house database and compared in cohorts of age 60-69, 70-79, and ≥80, regarding pre-existing medical conditions, treatment, clinical course including complications, and outcome. A multivariate analysis was conducted to identify prognostic factors for death and disability. A total of 256 patients (138 aged 60-69, 93 aged 70-79, 25 aged ≥80) with putative aneurysmal SAH who had been admitted to our hospital between January 1, 1996 and June 30, 2007 were extracted. The median follow-up of our total cohort was 35.5 months (range <1-154 months). Endovascular or conservative aneurysm treatment was applied more often with increasing age (p < 0.006). The 1-year survival rate was 78, 65, and 38 % in the three age groups, respectively (p = 0.0002); most of the patients died from the initial hemorrhage or from medical complications. Patients aged <70 with an initial World Federation of Neurosurgical Societies (WFNS) score of I-III showed the best clinical recovery. WFNS score, age, and clipping/coiling were extracted as prognostic factors from the Cox model. Elderly patients who get admitted with a good WFNS score (I-III) seem to benefit from aggressive treatment whereas caution seems to be warranted particularly in patients ≥70 years of age who get admitted in a WFNS score of IV and V because of their limited short- and long-term prognosis.
    No preview · Article · Dec 2012 · Journal of Neurology
  • R Veltkamp · E Jüttler · T Pfefferkorn · J Purrucker · P Ringleb
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    ABSTRACT: Study registries offer the opportunity to evaluate the effects of new therapies or to observe the consequences of new treatments in clinical practice. The SITS-MOST registry confirmed the validity of findings from randomized trials on intravenous thrombolysis concerning safety and efficacy in the clinical routine. Current study registries concerning new interventional thrombectomy techniques suggest a high recanalization rate; however, the clinical benefit can only be evaluated in randomized, controlled trials. Similarly, the experiences of the BASICS registry on basilar artery occlusion have led to the initiation of a controlled trial. The benefit of hemicraniectomy in malignant middle cerebral artery infarction has been demonstrated by the pooled analysis of three randomized trials. Numerous relevant aspects are currently documented in the DESTINY-R registry. Finally, the recently started RASUNOA registry examines diagnostic and therapeutic aspects of ischemic and hemorrhagic stroke occurring during therapy with new oral anticoagulants.
    No preview · Article · Sep 2012 · Der Nervenarzt
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    ABSTRACT: Background and purpose: The frequent use of a longer time window for recanalization therapy in patients with basilar artery occlusion (BAO) in daily practice is not supported by any scientific evidence. We investigated the relationship between time to recanalization therapy and functional outcome in BAO with data from the Basilar Artery International Cooperation Study (BASICS). Methods: BASICS is a prospective multicenter registry of patients (n=619) with radiologically confirmed BAO. We analyzed patients receiving intravenous thrombolysis or intra-arterial treatment. Patients were divided into 4 groups based on the interval between estimated time of BAO and start of recanalization therapy: ≤3 hours (n=134), >3 to ≤6 hours (n=151), >6 to ≤9 hours (n=56), and >9 hours (n=68). Primary outcome measure was poor functional outcome (modified Rankin scale score 4-6) after 1 month. We calculated adjusted risk ratios with 95% CIs using Poisson regression analyses with the ≤3 hours group as the reference group. Results: Patients had an increased risk of poor functional outcome as time to recanalization therapy became longer (≤3 hours: 62%; >3 to ≤6 hours: 67% [adjusted risk ratio, 1.06; 0.91-1.25]; >6 to ≤9 hours: 77% [adjusted risk ratio, 1.26; 1.06-1.51]; >9 hours: 85% [adjusted risk ratio, 1.47; 1.26-1.72]). Conclusions: Early recanalization therapy in patients with BAO is associated with a more favorable outcome with a significant increased chance of a poor outcome when recanalization therapy is started >6 hours after estimated time of BAO.
    Preview · Article · Sep 2012 · Stroke
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    ABSTRACT: Objectives: Single case reports suggest that black blood MRI (T1-weighted fat and blood suppressed sequences with and without contrast injection; BB-MRI) may visualize intracranial vessel wall contrast enhancement (CE) in primary angiitis of the central nervous system (PACNS). In this single-center observational pilot study we prospectively investigated the value of BB-MRI in the diagnosis of large artery PACNS. Methods: Patients with suspected large artery PACNS received a standardized diagnostic program including BB-MRI. Vessel wall CE was graded (grade 0-2) by two experienced readers blinded to clinical data and correlated to the final diagnosis. Results: Four of 12 included patients received a final diagnosis of PACNS. All of them showed moderate (grade 1) to strong (grade 2) vessel wall CE at the sites of stenosis. A moderate (grade 1) vessel wall CE grade was also observed in 6 of the remaining 8 patients in whom alternative diagnoses were made: arteriosclerotic disease (n = 4), intracranial dissection (n = 1), and Moyamoya disease (n = 1). Conclusions: Our pilot study demonstrates that vessel wall CE is a frequent finding in PACNS and its mimics. Larger trials will be necessary to evaluate the utility of BB-MRI in the diagnostic workup of PACNS.
    No preview · Article · Aug 2012 · Journal of neuroimaging: official journal of the American Society of Neuroimaging
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    ABSTRACT: Supratentorial superficial siderosis (SS) is a frequent imaging marker of cerebral amyloid angiopathy (CAA). It is most probably caused by focal subarachnoid hemorrhages (fSAHs). Based on single-case observations, it has been proposed that such fSAHs might be a predisposing factor for future intracranial hemorrhage. Here we tested the hypothesis if a SS as a residue of fSAHs must be regarded as a warning sign for future intracranial hemorrhage. Fifty-one consecutive patients with SS and no apparent cause other than possible or probable CAA were identified through a database search and followed-up for a median interval of 35.3 months (range 6-120 months). Main outcome measures were rate and location of new intracranial hemorrhages. Twenty-four patients (47.1 %) had experienced any new intracranial hemorrhage, 18 patients (35.3 %) had an intracerebral hemorrhage (ICH), and in 13 of them (25.5 %), the hemorrhage was located at the site of pre-existing siderosis. Six patients (11.7 %) had developed a new subarachnoid hemorrhage (SAH), four of them at the site of siderosis. Patients with SS are at substantial risk for subsequent intracranial hemorrhage. SS can be considered a warning sign of future ICH or SAH, which frequently occur adjacent to pre-existing SS. Prospective studies are needed to confirm these findings.
    No preview · Article · Jul 2012 · Journal of Neurology
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    ABSTRACT: Multimodal recanalization therapy in patients with acute basilar artery occlusion provides high recanalization rates. A substantial subset of treated patients survives with only minor or moderate functional handicap. However, long-term functional outcome and quality of life in these patients have rarely been systematically analyzed. In this monocentric retrospective study, we analyzed mortality, long-term functional outcome (modified Rankin Scale), and quality of life (36-Item Short-Form Health Survey questionnaire) in all consecutive patients who had been treated for acute basilar artery occlusion in our institution between December 2002 and December 2009. Ninety-one patients (57 male; median age, 65 years; range, 20-89 years) were treated by multimodal recanalization therapy. This included intravenous thrombolysis (n=32) with consecutive on-demand intra-arterial therapy (n=23) or intra-arterial therapy alone (n=59). The overall recanalization rate was 89%. After a median observation time of 4.2 years (range, 0.5-7.4 years), the mortality rate was 59%. Among the 35 survivors, 26 patients (74%) had a good or moderate long-term functional outcome (modified Rankin Scale ≤3). Health-related quality of life was better than that of unselected patients with stroke. Backward stepwise logistic regression identified intravenous thrombolysis (P=0.002) and female sex (P=0.001) as predictors of favorable functional long-term outcome (modified Rankin Scale ≤3). Coma at admission (Glasgow Coma Scale ≤8) was associated with poor outcome (modified Rankin Scale ≥4; P=0.036). Long-term survival is achieved in approximately 40% of patients with basilar artery occlusion treated with multimodal recanalization therapy. Approximately 75% of the survivors have a favorable functional long-term outcome with an acceptable quality of life.
    No preview · Article · May 2012 · Stroke
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    Full-text · Article · Mar 2012 · Clinical neurology and neurosurgery
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    ABSTRACT: Acute occlusions of the large intracranial arteries are relatively resistant to intravenous thrombolysis. Therefore, multimodal approaches combining intravenous thrombolysis with endovascular mechanical recanalization are increasingly being applied. In this setting, intravenous thrombolysis may facilitate subsequent mechanical thrombectomy. To test this hypothesis, we analyzed the influence of intravenous thrombolysis on net intervention time in subsequent endovascular mechanical recanalization. In this retrospective single-center analysis, we compared net intervention time with and without preceding intravenous thrombolysis in patients treated by endovascular mechanical recanalization between 01/2003 and 06/2010. The net intervention time was defined as the interval between the onset of endovascular thrombus manipulation and successful vessel recanalization. We identified 65 eligible patients, 35 of whom were treated by intravenous thrombolysis before mechanical therapy. Recanalization was achieved in 26 patients with (74%) and 23 patients without preceding intravenous thrombolysis (77%). In the case of successful recanalization, the net intervention time was significantly shorter in patients with preceding intravenous thrombolysis (24·8 ± 22·8 vs. 44·2 ± 40·5 min; P<0·05). This difference remained significant after restricting the analysis to the patients treated by the Penumbra Stroke System(©) (n=32). After three-months, patients with preceding intravenous thrombolysis were more likely to be functionally independent (modified Rankin Scale≤2) than those without (P<0·05). Our findings suggest that preceding intravenous thrombolysis may reduce the intervention time in patients treated by endovascular mechanical recanalization. However, due to the retrospective design of our study, these findings have to be interpreted with caution and need confirmation in a larger patient population.
    No preview · Article · Jan 2012 · International Journal of Stroke

Publication Stats

1k Citations
294.41 Total Impact Points


  • 2007-2015
    • Technische Universität München
      München, Bavaria, Germany
  • 2014
    • Klinikum Ingolstadt
      Ingolstadt, Bavaria, Germany
  • 2002-2013
    • Ludwig-Maximilian-University of Munich
      • Department of Neurology
      München, Bavaria, Germany
    • University Hospital München
      München, Bavaria, Germany
  • 2010
    • University of Vienna
      Wien, Vienna, Austria
  • 2004
    • University of New Mexico
      Albuquerque, New Mexico, United States