Hansjoerg Baezner

Deep frontal and periventricular age related white matter changes but not basal ganglia and infratentorial hyperintensities are associated with falls: cross sectional results from the LADIS study

Background: Global age related white matter changes (ARWMC) are associated with progressive gait disturbances and falls, hypothesised to result from interruptions of cortico-subcortical circuits controlling balance, posture and locomotion. Methods: The location of ARWMC in a large cohort of elderly non-disabled individuals with reported falls was analysed, using the cross sectional data of the Leukoaraiosis and Disability (LADIS) study. Detailed anatomical distributions of ARWMC assessed by MRI studies were analysed with respect to falls and balance performance. Results: The severity of global ARWMC was significantly associated with a history of falls in the year prior to study inclusion (22.2% in the mild, 31.6% in the moderate and 37.3% in the severe ARWMC group according to the Fazekas scale; p = 0.002). Analysing the anatomical distribution of ARWMC, using the semiquantitative Scheltens scale, in multivariate analysis, periventricular (p = 0.006) and frontal deep (p = 0.033) ARWMC were independently associated with falls. Furthermore, logistic regression identified frontal deep (p = 0.003) ARWMC, but not basal ganglia and infratentorial hyperintensities, as significantly associated with balance disturbances. Conclusion: The association of frontal and periventricular ARWMC with falls supports the hypothesis that interruption of frontal subcortical motor circuits lead to balance disturbances and hence to an increased risk for falls in ARWMC.

Ultrasound and Arterial Wall Disease

Rapid progress in non-invasive ultrasound techniques has resulted in a wide variety of clinical applications for the assessment of cerebrovascular diseases. Recent highlights in ultrasound research include the evaluation of vascular ageing as a degenerative process, the demonstration of plaque development, motion and vulnerability in atherosclerosis and multi-dimensional as well as innovative imaging techniques (e.g., compound imaging) to depict early and small vascular lesions. In addition, echo-contrast agents have been used to compensate for difficulties in visualising late, severe or subtotal obstructive plaques, but failed to be really superior to conventional techniques as evidenced in a prospective, multi-centre trial (Contrast Enhanced Duplex sonography versus Arteriography Studies – CEDAS). With increasing sophistication of ultrasound methodology, it becomes essential to establish standards for data acquisition and interpretation: three consensus meetings have provided detailed recommendations on quantification of carotid atherosclerosis, characterisation of carotid artery plaques and detection of microembolism by transcranial Doppler as a potential indicator of stroke risk.

Chronic deep brain stimulation for segmental dystonia.

Fourteen consecutive patients with segmental dystonia underwent chronic deep brain stimulation (DBS) surgery in the frame of a prospective study protocol. Twelve patients received chronic pallidal stimulation, while 2 patients with prominent dystonic tremor received chronic thalamic ventrointermediate nucleus stimulation. Twelve patients had primary dystonia, and 2 patients secondary dystonia. The Burke-Fahn-Marsden dystonia rating scale (BFM motor) showed a mean relative improvement of 57.3% at the first follow-up (FU1, mean 7 months) and 57.8% at the second follow-up (FU2, mean 16 months). The mean BFM scores were 34.9 ± 17.7 preoperatively, 14.9 ± 11.7 at FU1, and 14.8 ± 10.3 at FU2. Scores of the disability subscale improved by 43% at FU1 and 36% at FU2. Improvement was comparatively less in those patients with secondary dystonia. Dysarthria was a limitation of DBS in 4 patients when using high voltage. Overall, chronic DBS is a very effective treatment option for medically refractory segmental dystonia.

Sparse Decomposition and Modeling of Anatomical Shape Variation

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome.

Micrographia induced by pallidal DBS for segmental dystonia: a subtle sign of hypokinesia?

Recently parkinsonism has been reported as a rare side effect of globus pallidus internus (GPi) deep brain stimulation (DBS) for dystonia. In the present systematic prospective study in 11 patients with segmental dystonia not affecting distal arm function, we could demonstrate significant changes in handwriting characterized by mild micrographia following GPi-DBS. We propose that this finding reflects GPi-DBS-induced disturbances of basal ganglia function in terms of a mild hypokinetic syndrome, as a result of outflow alterations in pallido-thalamo-cortical pathways.

From trepidant abasia to motor network failure : gait disorders as a consequence of subcortical vascular encephalopathy (SVE) review of historical and contemporary concepts

Gait disorders in progressive subcortical vascular encephalopathy (SVE) and their impact on the burden of disability in the growing elderly population are underrepresented in medical scientific literature. The absence of a clear framework for the diagnosis and classification for gait disorders on the basis of SVE has multiple reasons: (1) neither movement disorder specialists nor stroke specialists are truly familiar with this topic and feel responsible for its treatment, (2) the existing terminology lacks a clear concept and a consistent classification, and (3) only in recent years have large prospective trials started to address the natural course of SVE. This article reviews the classical descriptions of gait disturbances with preferential view to our present concept of SVE, and comments on historical and current nosology of gait disorders aiming to propose for a new classification.

Bilateral deep brain stimulation for cervical dystonia in patients with previous peripheral surgery

There are no data available concerning whether patients with cervical dystonia who have recurrent or new symptoms after peripheral denervation surgery benefit similarly from pallidal deep brain stimulation compared with patients who receive primarily pallidal stimulation.

Vasoneuronal coupling in migraineurs after subcutaneous sumatriptan: a TCD study.

According to the trigeminovascular model of pain in migraine, sterile neurogenic inflammation of dural vessels stimulates nociceptive fibres of the trigeminal nerve. Sumatriptan, a 5-HT1 receptor agonist, blocks this reaction and mediates vasoconstriction of meningeal arteries. However, it is uncertain, whether sumatriptan also has a vasoconstrictive effect on cerebral arteries, which may influence vasoneuronal coupling and induce secondary cerebral blood flow changes. We studied changes of cerebral blood flow velocity (CBFV) and the pulsatility index (PI) in the posterior cerebral artery (PCA) after stimulus activation before, 10 min and 30 min after subcutaneous application of 6 mg sumatriptan, in order to assess potential vasoactive effects on cerebral circulation. CBFV was recorded from both PCAs simultaneously in 27 migraineurs (twenty women, seven men, mean age 29 years), and arterial blood pressure (BP), heart rate (HR) and respiration rate (RR) were monitored. Although the mean diastolic blood pressure rose significantly from 75 mm Hg to 81 mm Hg (P<0.05) and systolic blood pressure and respiration rates remained constant, average CBFV values remained constant. Similarly, the relative increase of CBFV by visual stimulation, which is clearly higher compared to controls in other studies (55.0% before, 52.6% after 10 min, and 52.4% after 30 min), and absolute mean values for CBFV and PI did not change after visual stimulation. These results provide evidence against the hypothesis that sumatriptan produces vasoconstriction in the intracranial human arterial circulation as a potential risk of cerebral ischemia.

Magnetic resonance imaging demonstration of fascicular inflammation in sixth nerve palsy as the presenting symptom in multiple sclerosis.

cose (58 mg/dl) levels, intrathecal IgG and IgM production, and positive oligoclonal bands – therefore, a second MRI was performed assuming a possible inflammatory sixth nerve lesion. High resolution MRI of the sixth nerve demonstrated a normal cisternal segment but a lesion of the fascicular part of the sixth nerve on the right ( fig. 1 ), without any further brain or spinal cord abnormalities at that point. Visually evoked potentials showed a delayed and abnormal potential on the right, indicating possible asymptomatic slight optic nerve involvement. Results of auditory, somatosensory and motorevoked potentials were normal. Extensive laboratory investigations of serum and CSF failed to show evidence of an alternative etiology, and thus, the diagnosis of possible multiple sclerosis (MS) was made. The patient was treated with intravenous methylprednisolone 500 mg/day for 3 days showing fast and marked improvement of symptoms, and complete resolution of diplopia and weakness of abduction subsequently. Follow-up MRI at 3 and 6 months demonstrated multiple new periventricular brain lesions fulfilling McDonald criteria [5] of MS. Dear Sir, The abducens nerve is a small anatomical structure and the most commonly affected nerve in ocular motor nerve palsies [1, 2] . Recent progress in magnetic resonance imaging (MRI) sequence technology has made it possible not only to visualize pathology in the pontine parenchymal portion of the sixth nerve but also in the cisternal segment [3, 4] .

Cerebellar Stroke With Speed-Dependent Gait Ataxia

To the Editor: We report on a 63-year-old woman with ischemic stroke of the right cerebellar hemisphere. Her symptoms, consisting of acute gait ataxia and left hemiataxia, were resolved in the following weeks, but we detected a speed-dependent improvement in her gait by moving fast. We therefore believe that the hypothesis of an autonomic spinal gait program becomes more evident and could be used in rehabilitation. It was recently shown that gait training under maximum speed improves gait deficit in stroke patients.1 Despite the frequency of cerebral ischemic stroke, it is often difficult to answer the question concerning the persistence of an acute neurological deficit. Usually, a good clinical outcome …