[Acute vestibular syndrome : Clinical examination outperforms MRI in the detection of central lesions]. / Das akute vestibuläre Syndrom : Die klinische Untersuchung ist der MRT bei der Aufdeckung zentraler Läsionen überlegen.

A significant number of patients who seek medical treatment in an emergency department because of vertigo or dizziness, suffer from acute vestibular syndrome. This is characterized by sustained vertigo, horizontal or horizontal rotatory jerk nystagmus, and unsteady stance and gait. In the acute situation it is crucial to differentiate patients with a peripheral vestibular disorder from those with a central disease. A number of recent studies have shown that a structured clinical examination enables a reliable differential diagnosis of central or peripheral disorders. Such an examination includes the head impulse test, an alternating cover test to detect a skew deviation of the eyes, and observation of nystagmus in different positions of gaze and using Frenzel goggles. This examination is more sensitive for the detection of brainstem stroke than magnetic resonance imaging (MRI), at least within 48 h after symptom onset. As these facts are still little known, in practice there is an overuse of cost-intensive imaging with computed tomography and MRI, and a number of patient brainstem strokes in the vertebrobasilar circulation may be missed. This paper describes the relevant studies on this topic.

Detection of intracranial circulatory arrest in brain death using cranial CT-angiography.

BACKGROUND AND PURPOSE: Computed tomographic-angiography (CT-A) is becoming more accepted in detecting intracranial circulatory arrest in brain death (BD). An international consensus about the use and the parameters of this technique is currently not established. We examined intracranial contrast enhancement in CT-A after clinically confirmed BD, compared the results with electroencephalography (EEG) and Transcranial Doppler Ultrasonography (TCD) findings and developed a commonly applicable CT-A protocol. METHODS: Prospective, monocentric study between April 2008 and October 2011. EEG, TCD and CT-A were performed in 63 patients aged between 18 and 88 years (mean, 55 years) who fulfilled clinical criteria of BD. Evaluation of opacification of cerebral vascular territories in CT-A was performed in arterial as well as in venous scanning series by a neuroradiologist and a neurointensivist/neurosurgeon together. RESULTS: CT-A demonstrated a 95% sensitivity in detecting intracranial circulatory arrest when analysing arterial scanning series. We never observed venous blood return in internal cerebral veins. In three cases, BD confirmation by EEG failed because of artefacts. Confirmation of BD by TCD failed in two cases because of absent temporal window. In three cases, TCD demonstrated residual blood flow. CONCLUSION: CT-A is easily accessible in almost every hospital, offers a high spatio-temporal resolution, is operator independent and inexpensive. The results of CT-A are comparable to other established brain perfusion techniques in BD. An international consensus should be established to ascertain consistent parameters similar to fixed guidelines for other ancillary procedures to determine BD in order to prevent different scanning and evaluation protocols for detecting intracranial circulatory arrest.

[Medicolegal assessment of post-traumatic vertigo]. / Begutachtung des posttraumatischen Schwindels.

Post-traumatic vertigo refers to a group of different disorders which occur following trauma, mainly closed head injury and whiplash injury of the cervical spine. Aside from headaches, vertigo is the most common symptom in this group of patients. In general, there are two main groups of patients with post-traumatic vertigo: those with documented vestibular dysfunctions and those without. The most common post-traumatic vestibular disorders are benign paroxysmal positioning vertigo, labyrinthine concussion, canal dehiscence and otolithic lesions. Some of these disorders are characterized by spontaneous improvement or recovery over weeks or months and some may also be treated effectively. A number of patients, however, develop phobic postural vertigo requiring psychiatric or psychosomatic exploration.

Trochlear palsies caused by isolated trochlear schwannomas.

PURPOSE: To describe clinical features and management of 4 patients suffering from unilateral superior oblique palsies due to MRI-documented trochlear nerve schwannomas. METHODS: Chart reviews of 4 patients seen at the departments of ophthalmogy and neurology at the University of Mainz. RESULTS: All four patients were male, aged 36 to 72 years at initial presentation. None suffered from neurofibromatosis. The history of double vision prior presentation was 9 months to 13 years, follow-up time was 9 to 156 months. Two patients didn't receive any intervention: one remained stable over the follow-up time of 9 months. In patient #2, fourth nerve palsy was diagnosed 13 years prior to confirmation of a trochlear schwannoma by high-resolution MRI. In the third patient disturbing diplopia and head tilt were sufficiently corrected by strabismus surgery (combined oblique muscle surgery). The fourth patient had received stereotactic radiotherapy of an 8 mm schwannoma. He remained unchanged in the orthoptic measurements for 3,5 years. None of these patients developed any additional symptoms or signs of further cranial nerve or central nervous system involvement. CONCLUSION: A trochlear nerve schwannoma is a possible cause of an isolated unilateral superior oblique palsy. MRI is a helpful tool for diagnosis and follow-up. Conservative management seems to be justified as patients can remain unchanged over years.

Eye movement involvement in Parry-Romberg Syndrome: a clinicopathologic case report.

We report the case of a 38-year-old woman who developed a progressive bilateral disease in which the eye motility disorder-diplopia-is the outstanding feature over a period of 12 years. The muscle biopsy of the medial rectus muscle did not show any trace of striated muscle. To the best of our knowledge, this is the first pathological report in an affected extraocular muscle of a patient with Parry-Romberg syndrome (PRS). Previous rare reports of diplopia in PRS have been attributed to enophthalmos, progressive atrophy of the orbit, ocular motor nerve dysfunction, or mechanical restrictions.

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.

[Horner's syndrome -- update on neuroanatomy, topographic diagnosis and etiology]. / Das Horner-Syndrom -- Ein Update zur Neuroanatomie, topographischen Differenzialdiagnostik und Atiologie.

Due to the complex neuroanatomy of the sympatho-excitatory pathway, Horner's syndrome represents a clinical sign that may result from a variety of lesions in the central and peripheral nervous system. The purpose of the present communication is to help the reader to localize the site of the lesion and to demonstrate the most common etiologic mechanisms resulting in Horner's syndrome. The functional anatomy of the sympathetic supply to the iris, eyelids, facial sweat glands and blood vessels is reviewed and in particular the structure of the central pathway updated. Moreover, pharmacological testing and tests of sudomotor function are described that may help to guide the decision regarding useful additional diagnostic, especially neuroimaging procedures. Finally, a schematic overview is given on the most common pathology, considering additional clinical signs and symptoms.

[Autoimmune functional disorders of the thyroid during interferon-beta-1b treatment in patients with multiple sclerosis. Case report and literature review]. / Autoimmune Funktionsstörungen der Schilddrüse unter Interferon-beta-1b-Therapie bei Patienten mit Multipler Sklerose. Kasuistik und Literaturübersicht.

Occurrence of thyroid autoimmunity and dysfunction following interferon alpha treatment of viral hepatitis and other diseases are known adverse effects and have been ascribed to the cytokine's general immunomodulatory and -activating properties. However, in spite of its extensive application, there have been few reports of such incidents during interferon beta (IFN-beta-1a/b) therapy, which is considered the standard treatment of relapsing-remitting multiple sclerosis (MS), and prospective studies have been published only recently. Here we present the case of a 38-year-old woman with Graves' disease including massive thyroid-associated ophthalmopathy appearing de novo following IFN-beta-1b therapy for MS. A literature search revealed an 11% (5% clinically overt) overall incidence of de novo thyroid dysfunction in IFN-beta-treated MS patients, mostly autoimmune hyperthyroidism. (Large-scale comparative studies for IFN-beta-1a are not available at present). Specific treatment but not necessarily discontinuation of IFN-beta-1b therapy was required in most cases. Female gender, pre-existing thyroid autoimmunity, and family history of thyroid disorders are presumable risk factors for thyroid dysfunction de novo during IFN-beta-1b treatment.

Cranial nerve function in workers exposed to polychlorinated dioxins and furans.

OBJECTIVE: To look for possible effects of polychlorinated dioxins and furans (PCDD/F) on cranial nerve function. MATERIAL AND METHODS: Clinical and neurophysiological examinations [visual and brainstem auditory evoked potentials (VEP and BAEP), blink reflex] in 121 PCDD/F exposed workers of one pesticide producing plant. RESULTS: BAEP abnormalities were more frequent in workers with chloracne (6 of 33 workers, 18.2%) than in those without chloracne (7 of 84, 8.3%), but this was not statistically significant (chi2: 2.33). VEP abnormalities were seen in one worker with and two without chloracne. Clinically visual functions were normal except in one worker, who was amaurotic since birth. Blink reflex abnormalities without corresponding clinical findings were observed in two patients without chloracne. CONCLUSION: Severe exposure to PCDD/F is not followed by clinical signs of cranial nerve dysfunction but may create an increased risk for abnormal BAEP findings, which were more than twice as common in workers with chloracne. Although this difference did not reach statistical significance, it cannot exclude a toxic effect of PCDD/F, as statistical significance is difficult to achieve with such small numbers of workers. In none of the workers, BAEP abnormalities were accompanied by clinical signs of hearing dysfunction.

Abduction paresis with rostral pontine and/or mesencephalic lesions: Pseudoabducens palsy and its relation to the so-called posterior internuclear ophthalmoplegia of Lutz.

BACKGROUND: The existence of a prenuclear abduction paresis is still debated. METHODS: In a retrospective design, we identified 22 patients with isolated unilateral (n = 20) or bilateral (n = 2) abduction paresis and electrophysiologic abnormalities indicating rostral pontine and/or mesencephalic lesions. Another 11 patients had unilateral abduction paresis with additional ocular motor abnormalities indicating midbrain dysfunction. Eight of these 11 patients also had electrophysiological abnormalities supporting this location. Electrophysiological examinations in all patients included masseter and blink reflexes (MassR, BlinkR), brainstem auditory evoked potentials (BAEP), and direct current elctro-oculography (EOG). RESULTS: Unilateral MassR abnormalities in patients with unilateral abduction paresis were seen in 17 patients and were almost always (in 16 of 17 patients) on the side of the abduction paresis. Another 11 patients had bilateral MassR abnormalities. BlinkR was always normal. EOG disclosed slowed abduction saccades in the non-paretic eye in 6 patients and slowed saccades to the side opposite to the abduction paresis in another 5 patients. Re-examinations were done in 27 patients showing normalization or improvement of masseter reflex abnormalities in 18 of 20 patients and in all patients with EOG abnormalities. This was always associated with clinical improvement. CONCLUSIONS: Electrophysiologically documented or clinically evident rostral pontine and/or mesencephalic lesions in our patients exclude an infranuclear intrapontine 6th nerve lesion and indicate the existence of an abduction paresis of prenuclear origin. An increased tone of the antagonistic medial rectus muscle during lateral gaze either by abnormal convergence or impaired medial rectus inhibition seems most likely.

The course of corticofacial projections in the human brainstem.

Transcranial magnetic stimulation was used to investigate the corticofacial projections in 53 patients with (n = 28) and without (n = 25) central facial paresis due to unifocal ischaemic lesions at different brainstem levels. Lesion topography documented by MRI studies was correlated with the electrophysiological findings. In the majority of patients the corticofacial fibres travel within the ventromedial base of the pons and cross the midline at the level of the facial nucleus. In some individuals, however, we found evidence that corticolingual fibres form an 'aberrant bundle' in a paralemniscal position at the dorsal edge of the pontine base. In other patients the corticofacial fibres loop down into the ventral part of the upper medulla, cross the midline and ascend in the dorsolateral medullary region ipsilaterally to the facial nucleus. The findings suggest that facial paresis due to a brainstem lesion may present as contralateral supranuclear facial paresis by a lesion of the cerebral peduncle, pontine base, the aberrant bundle and the ventral medulla. Supranuclear facial paresis ipsilateral to the lesion side may result from a lesion in the lateral medulla, and facial paresis of the supranuclear type may be imitated by a lesion of the peripheral facial nerve in the dorsolateral medulla with involvement of the lower pons.

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.

[Current concepts in diagnosing brain death in Germany]. / Aktueller Stand der Hirntoddiagnostik in Deutschland.

Diagnosis of brain death requires definite evidence of an acute CNS catastrophe and exclusion of complicating medical conditions that may confound clinical assessment. Acute CNS catastrophe may be due to direct ("primary") brain damage (e.g., intracerebral hemorrhage, severe concussion, brain tumors), or indirect ("secondary") brain damage (e.g., cerebral hypoxia following cardio-pulmonary resuscitation). The cardinal findings in brain death are coma, absence of brainstem reflexes, and apnea. Persistence of these clinical signs determines brain death. In Germany, the intervals of a repeat clinical evaluation are at least 12 hours in patients with primary, and at least 72 hours in those with secondary brain damage. Electroencephalographically documented absence of electrical activity for at least 30 minutes or by means of transcranial Doppler ultrasonography or isotope angiography documented intracranial circulatory arrest also confirm brain death. Under such conditions, a repeat clinical evaluation is unnecessary in patients with clinical brain death signs. First of all, brain death is a clinical diagnosis. Confirmatory tests are not mandatory in most situations. In Germany, confirmatory tests are required in newborns, infants below the age of 2 years, and patients with infratentorial brain damage.

Isolated superior oblique palsies with electrophysiologically documented brainstem lesions.

Over a 13.5-year period, we observed 10 patients with isolated superior oblique palsies in whom electrophysiological abnormalities indicated brainstem lesions. In 7 patients unilateral masseter reflex abnormalities were seen, and were located on the side of the superior oblique palsy in 2 patients and on the opposite side in 5 patients. Two patients had slowed gain of following eye movements to the side contralateral to the superior oblique palsy. Slowed adduction saccades in the eye contralateral to the superior oblique palsy were seen in 1 patient. Clinical improvement was frequently (in 7 of 10 patients) associated with improvement or normalization of electrophysiologic findings. Magnetic resonance imaging (MRI) was normal, showing no evidence of brainstem lesions in 6 patients. Unilateral superior oblique palsy may be the only clinical sign of a brainstem lesion. Although such a cause may be underdiagnosed if based on MRI-documented lesions only, it remains a rare condition.

Masseter reflex latencies and amplitudes are not influenced by supratentorial and cerebellar lesions.

The aim of this study was to investigate possible influences of suprasegmental lesions on the masseter reflex. The masseter reflex was elicited in 54 patients with supratentorial (37 patients) or cerebellar (17 patients) lesions 3-11 days after the acute onset of clinical disease. Patients showing lesions within the pons and midbrain on thin-slice magnetic resonance imaging were excluded from evaluation. The testing procedure included an additional facilitating maneuver (opening and closing the jaw before tapping). Masseter reflex latencies, interside differences, and amplitudes were within the normal range in all patients. Latencies were not different with and without the facilitating maneuver. Amplitudes were significantly higher with the maneuver, but interside differences of amplitudes were unchanged. Masseter reflex abnormality can be taken as a reliable measure of direct involvement of the reflex arc.

[Spontaneous intracranial hypotension syndrome. Clinical, neuroradiological and cerebrospinal fluid findings]. / Spontanes Liquorunterdrucksyndrom. Klinische, neuroradiologische, nuklearmedizinische und Liquor-Befunde.

We report 11 patients with orthostatic headache due to spontaneous intracranial hypotension. Nausea (3 patients) and abducens palsy (2 patients) were the main additional symptoms. Ten patients had CSF pleocytosis (6 to 43 white cells/microliter) and/or increased protein (581 to 1668 mg/l). CT and/or MRI documented bifrontal accentuated subdural hygromas and hematomas in 5 patients. MRI also documented diffuse meningeal gadolinium enhancement in all 4 patients examined, and descent of the brain in one. Cisternography was done in 9 patients and revealed a decreased or absent activity over the convexities and early detection of the tracer in the bladder in all, and a CSF leak at the cervicothoracal junction in 2 patients. Most patients improved with bed rest, increased fluid intake (oral or intravenous), steroids, and/or epidural blood patch. Subdural hematomas increased in 2 patients and have to be drained. Spontaneous intracranial hypotension is due to a CSF leak followed by decreased CSF volume and hydrostatic CSF pressure changes. The locations of the leaks are mainly cervical or at the cervicothoracal junction. MRI always documents diffuse meningeal gadolinium enhancement. Treatment of choice is an epidural blood patch. Surgical treatment may be needed in patients with subdural hematomas or meningeal diverticula. Prognosis is typically good, but subdural hematomas may occasionally lead to an increased intracranial pressure.

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.