Stefan Gottschalk

Beneficial effects of 3,4-diaminopyridine on positioning downbeat nystagmus in a circumscribed uvulo-nodular lesion

Sirs: Central positioning downbeat nystagmus (pDBN) presents with transient nystagmus in supine or the head hanging position in the absence of DBN in the head erect position. In contrast to central positional downbeat nystagmus, pDBN requires rapid head positioning manoeuvres to be elicited. The pathomechanism and therapy of central pDBN is not yet known and circumscribed lesions are missing so far [1, 2]. We examined the effect of 3,4-diaminopyridine (DAP) [3, 4] on the oculomotor behavior of a patient with pDBN. The 43-year old man had a 4 years history of gait unsteadiness. Cranial MRI and histology revealed a multi-nodular dysembroplastic neuroepithelial tumor. Immediately after partial neurosurgical removal he suffered from head positioning vertigo and vertical oscillopsia on bending the head rapidly into the supine or head hanging position. Neurological examination revealed mild gait ataxia and impaired downward smooth pursuit eye movements. Rapid but not slow head positioning manoeuvres into the head hanging position elicited a typical DBN which increased within a few seconds and lasted for about 30 s. Eye movements were recorded with the Eyelink II system [3], electro-oculography and the scleral search coil system. Vertical vestibulo-ocular reflex (VOR) was tested by rapid head pulses. Visually guided saccades were examined with targets presented on lateral gaze; smooth pursuit eye movements at 0.2 and 0.3 (±16 ). Vestibular turntable stimulation and the VOR tilt suppression were analyzed [5]. Eye movements were recorded prior and up to 90 minutes after DAP ingestion (20 mg). The patient gave informed written consent. The protocol was approved by the local ethics committee. Statistical differences were significant for p < 0.05. There was no nystagmus on lateral gaze with the head erect. When the head was rapidly turned back into the head hanging position there was profound downbeat nystagmus, which increased on lateral and downward gaze (Fig. 1A). Slow phase velocity (SPV) of pDBN was linear and revealed a crescendo/decrescendo time course (Fig. 1B) with a maximal peak SPV of 72 /s. Downward but not upward smooth pursuit was impaired (Fig. 1C, D; grey). Horizontal pursuit, saccades, subjective visual vertical and responses to caloric irrigation were normal. Vertical (up: 0.93 ± 0.4; down: 0.93 ± 0.6) and horizontal VOR gain was normal. Prolonged head shaking elicited a perverted nystagmus [6]. Time constants of postrotatory nystagmus were severely prolonged and dumping of the postrotatory vestibular time constant by head tilts was virtually abolished (without: 20.5 s, with head tilt: 22.3 s). Following DAP ingestion downward smooth pursuit (gain: 0.63 ± 0.13 to 0.77 ± 0.1; p < 0.001; Fig. 1C, D; dark) and peak SPV of pDBN (72 /s–56 /s; p < 0.001; Fig. 1B) significantly improved by on average 22% and 21%, respectively. Before surgery, T2-weighted cranial MR images showed multilocular lesions in the nodulus, ventral uvula, and immediately adjacent to the fourth ventricle (Fig. 1E–H). The lesions did not affect the flocculus, paraflocculus, posterior vermis (Fig. 1G) and the vestibular nuclei. Several lines of evidence indicate that pDBN was caused by the uvulo-nodular lesion: (1) the prolongation of postrotatory nystagmus [7], (2) the abolished tilt suppression of the postrotatory vestibular nystagmus by pitching the head forward [7], (3) perverted headshaking nystagmus [6] and (4) the fact that pDBN appeared immediately after the uvulo-nodular tumor resection. Importantly, there was exclusively pDBN suggesting inappropriate velocity storage mechanisms of vertical angular VOR signals. For the first time we describe small but beneficial effects of DAP on pDBN. DAP reduced pDBN and downward pursuit to a similar extent suggesting a common pathomechanism. Deficient downward smooth pursuit has recently been Prof. Dr. C. Helmchen, MD (&) T. Sander Æ P. Trillenberg, MD H. Rambold, MD Æ A. Sprenger Dept. of Neurology University of Lübeck Ratzeburger Allee 160 D-23538 Lübeck, Germany Tel.: +49-451/500-2927 Fax: +49-451/500-2489 E-Mail: Christoph.Helmchen@neuro.uniluebeck.de

Intralabyrinthine schwannoma affecting the low but not high frequency function of the vestibulo-ocular reflex: implications for the clinical diagnosis of chronic peripheral vestibular deficits.

Peripheral vestibular hypofunction can be identified by asymmetric vestibular responses to caloric irrigation of the horizontal semicircular canal or by the head impulse test.1 Whereas the first test investigates the low frequency function of the vestibulo-ocular reflex (VOR) the latter assesses the high frequency function. The high frequency VOR function is usually more persistently impaired in unilateral vestibular lesions (eg, vestibular neuritis) than the low frequency function and thus the more sensitive parameter to detect chronic peripheral vestibular deficits.2 Contrary to this current vestibular knowledge, we present a patient with a chronic peripheral vestibular deficit showing normal high frequency but impaired low frequency VOR function. This unusual lesion pattern was caused by an intralabyrinthine schwannoma. A 47-year-old patient presented with a 3 month history of repetitive episodes of vertigo, nausea and lateropulsion to his right side. The first episode lasted 1.5 h followed by short lasting (seconds to 15 min) episodes once a day. The patient reported a similar episode of vertigo 1 year previously, at that time associated with an acute hearing loss on the right side and persisting tinnitus ever since. Apart from moderate right sided hypacusis, neurological examination was normal in the asymptomatic stages during follow-up examinations over the next 2 years. Particularly, there was no spontaneous or head shaking nystagmus and no gaze evoked nystagmus. After written …

Cranial pachymeningitis: a rare neurological syndrome with heterogeneous aetiology

Cranial pachymeningitis is a poorly understood syndrome, defined by leptomeningeal thickening and typical gadolinium enhanced MRI. The heterogeneous clinical and aetiological features of five patients with both focal and diffuse pachymeningitis are presented. The initial symptoms included headache (n=3), sensory Jackson seizures (n=1), hemiparesis (n=1), episodes of short lasting hemiataxia (n=1), hemihypaesthesia (n=1), aphasia (n=1) and confusion (n=2). MRI scans revealed focal (n=3) or diffuse (n=2) leptomeningeal gadolinium enhancement and cortical swelling (n=4). In addition, one case presented with a subarachnoid and a second with an intracerebral haemorraghe. CSF findings were variable and showed clear lymphomonocytic pleocytosis in 3/5 cases. Infectious diseases were extensively excluded in all cases. Leptomeningeal biopsies of two cases revealed perivascular inflammation, indicating central nervous system vasculitis. In the cases presented, pachymeningitis was caused by primary central nervous system vasculitis (n=2) and rheumatoid arthritis (n=2). In one case, the cause remained unclear.

Fehlbildungen des Felsenbeins

ZusammenfassungDie Fehlbildungen des Felsenbeins lassen sich im Wesentlichen als Fehlbildungen des Mittelohrs oder des Innenohrs klassifizieren. Sie können mit Normvarianten der arteriellen und venösen Gefäße sowie einem abnormen Verlauf des N. facialis einhergehen, deren Kenntnis präoperativ von großer Bedeutung ist. Die radiologische Deskription der Mittelohrfehlbildungen durch die Computertomographie liefert relevante Information für die Versorgung mit einem Hörgerät oder einer hörverbessernden Mittelohroperation. Bei Innenohrfehlbildungen werden durch die Computertomographie und Magnetresonanztomographie die Voraussetzungen für ein Cochlea-Implantat geprüft und Konstellationen erfasst, die ein erhöhtes Komplikationsrisiko bedingen. Kongenitale Liquorfisteln werden besprochen, soweit sie mit Fehlbildungen assoziiert sind. Von den eigentlichen Fehlbildungen des Mittel- und Innenohrs sind Entwicklungsanomalien des Felsenbeins zu unterscheiden. Sie können im Zusammenhang mit einer echten Fehlbildung oder isoliert auftreten. Die Entwicklungsanomalien betreffen neben Normvarianten der arteriellen und venösen Gefäße insbesondere die Form des Processus mastoideus mit den knöchernen Grenzen zur hinteren und mittleren Schädelgrube.AbstractCongenital malformations of the temporal bone essentially correspond to dysgenesis of the middle and/or inner ear. These malformations are often associated with anatomic variations of arterial and venous vessels as well as an aberrant course of the facial nerve. Anatomic variations as such do not cause functional deficits and should be differentiated from true malformations. The CT appearance of malformations and anatomic variations of the temporal bone has to be understood to facilitate appropriate surgical correction or implantation of hearing devices and to avoid complications during surgical procedures. Several classifications of middle and inner ear malformations are presented. Congenital cerebrospinal fluid fistulae are discussed with respect to their association to inner ear malformations. Developmental anomalies of the temporal bone are an additional point of the discussion.

Japanese encephalitis in Western Europe

Japanese encephalitis is the leading cause of viral encephalitis in Asia. In Western Europe, however, Japanese encephalitis has not been reported so far. We report on a 59-year-old German woman with typical neurological symptoms and clinical presentation 8 days after a journey to northern China. The case report summarizes the patients clinical course as well as pathological findings in blood samples, the cerebro-spinal fluid, MRI scans, and EEGs.

Progression of chronic subdural haematomas in an infant boy after abusive head trauma

Abusive head trauma is a serious form of child abuse that can lead to severe neuropsychological sequelae or death in infants. In questionable cases, without a confession from the caregivers and ambiguous clinical information, evidence for the diagnosis of abusive head trauma is often based on typical patterns that have been observed in neuro-imaging. This study shows the progressive evolution of multifocal chronic subdural haematomas, including re-bleedings, in a case of abusive head trauma in an infant boy who was documented with repeated magnetic resonance imaging. The chronic subdural haematomas occurred during closely monitored in-patient rehabilitative care, and repeated maltreatment did not appear to be likely. Due to excessive growth, neurosurgical intervention with endoscopic craniotomy, evacuation of the subdural haematomas and temporal external cerebrospinal fluid drainage was performed with a favourable recovery. This study discusses the current pathophysiological knowledge concerning the development and clinical course of chronic subdural haematomas and draws relevant conclusions for the clinical practice and psychosocial management of caring for victims of abusive head trauma.

Excessively increased CSF tau in progressive multifocal leukoencephalopathy

The analysis of cerebrospinal fluid (CSF) biomarkers has become useful tool in the diagnosis of memory diseases. The combinaion of increased levels of total tau (t-tau) and phosphorylated tau p-tau) together with a decreased amyloid-beta 1-42 peptide level s a tool to differentiate patients with Alzheimer’s disease (AD) rom healthy subjects and patients with other neurological disases with a high specificity. Elevated levels of t-tau were also escribed in classical tauopathies, e.g. corticobasal degeneration nd frontotemporal dementia. Additionally, high tau values were ound in neurovascular diseases (vascular dementia, stroke), noral pressure hydrocephalus, head injury, neuromuscular diseases, nd AIDS-dementia complex, too [1]. Very high t-tau CSF levels ere reported in Creutzfeldt-Jakob disease (CJD) and within the rst days after severe head trauma due to diffuse axonal injury [2]. Progressive multifocal leukoencephalopathy (PML) is a demyeliating disease of the CNS and caused by lytic infection of ligodendrocytes with the JC polyomavirus [3]. PML is a feared omplication of immunosuppressive disorders especially in the ontext of a HIV infection [4]. In recent years, a variety of cases

MRI of the eye muscles in a case of ophthalmoplegia caused by common carotid artery occlusion suggests ischemic myopathy.

Ocular muscle palsies following carotid artery disease is thought to be caused by ischemia of the cranial oculomotor nerves but it may also be due to ischemia of the extraocular muscles (EOM). We studied a patient with common carotid artery occlusion syndrome (CCAOS) to elucidate the two competing hypotheses. MRI and sonography of the orbita showed oedematous swelling of all left EOM. MRI short-tau inversion recovery (STIR) sequences showed hyperintensities and a prolonged T2-relaxation time in EOM indicating muscle oedema. It decreased within two weeks as ophthalmoplegia improved. For several reasons ischemic EOM myopathy rather than ischemic neuropathy seems to be the morphological correlate of ophthalmoplegia after ipsilateral CCAOS in this patient.

Lumbosacral glioblastoma and leptomeningeal gliomatosis complicating the course of a cervicothoracic astrocytoma WHO grade II

Case reportThe reported female patient underwent sub-total resection of an intra-medullary cervicothoracic astrocytoma classified as WHO grade II in 1984 at the age of 18 months and received local irradiation. In 1989, a local recurrence was diagnosed and a partial resection was performed. Sixteen years later, a small recurrent cervicothoracic tumour was found and spinal seeding to the equine nerve roots and the left cerebellar cortex was apparent on MRI. The patient was implanted with a ventriculoperitoneal shunt for a pseudo-tumour cerebri producing papilloedema, which eventually lead to amaurosis. After an extended biopsy, the invasive lumbosacral tumour was classified as glioblastoma multiforme. Two months later, the patient died after rapid progression of the caudal cranial nerve dysfunction.Discussion and conclusionAnaplastic progression and dissemination of spinal astrocytomas even two decades after initial diagnosis and treatment are rare. Therapies and diagnostic follow-up strategies are discussed.

Persistence of perilymph fistula mechanism in a completely paretic posterior semicircular canal

The three dimensional eye movements (search coil technique) of a patient with a completely paretic left posterior semicircular canal as a result of a perilymph fistula (PLF) were studied. The patient still exhibited pressure induced nystagmus that obeyed Ewald’s first law. This finding cannot be explained by otolith stimulation, but might indicate that PLF mechanisms either persist in canal plugging or act on the ampulla by directly deflecting the cupula.