The olfactory bulb volume in patients with idiopathic Parkinson's disease.

BACKGROUND AND PURPOSE: This study addresses the question of whether the neuropathological findings on the olfactory bulb (OB) in idiopathic Parkinson's disease (IPD) correspond to a detectable change in volume of the OB. Additionally, the relationship between OB volume and residual olfactory function, clinical disease characteristics and age are investigated. METHODS: Fifty-two IPD patients were investigated and compared to 31 healthy age-matched controls. All participants were scanned using a 3 T magnetic resonance imaging MRI scanner including a T2 DRIVE sequence in coronal slices through the OB. The OB volumes were measured via manual segmentation of the OB. Olfactory testing was carried out using the Sniffin' Sticks test battery. RESULTS: The OB volume in the IPD group was 42.1 mm³ (SD ± 11.6) for the right and 41.5 mm³ (SD ± 11.7) for the left OB and showed no difference from the controls. Additionally, there were no significant correlations between OB volume and disease characteristics such as disease duration or Unified Parkinson's Disease Rating Scale motor score. Likewise, patients' residual smell function did not correlate with their OB volume. In contrast, controls indicated a correlation between smell function and OB volume. CONCLUSION: The study shows that high resolution MRI does not show a detectable volume loss of the OB in PD patients. It is concluded that OB measurement using in vivo high resolution MRI at 3 T is not helpful to identify IPD.

Bedside differentiation of vestibular neuritis from central "vestibular pseudoneuritis".

Acute unilateral peripheral and central vestibular lesions can cause similar signs and symptoms, but they require different diagnostics and management. We therefore correlated clinical signs to differentiate vestibular neuritis (40 patients) from central "vestibular pseudoneuritis" (43 patients) in the acute situation with the final diagnosis assessed by neuroimaging. Skew deviation was the only specific but non-sensitive (40%) sign for pseudoneuritis. None of the other isolated signs (head thrust test, saccadic pursuit, gaze evoked nystagmus, subjective visual vertical) were reliable; however, multivariate logistic regression increased their sensitivity and specificity to 92%.

Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits.

PURPOSE: Intracranial hypotension has been reported as a complication of accidental drainage after surgical treatment in several cases. Application of negative pressure systems (wound drains, VAC(®)-therapy, chest tube drainage) had typically led to severe intracranial hypotension including intracranial hemorrhage and tonsillar herniation. In the last year the authors observed 2 cases of accidental spinal drainage of CSF in patients with neurological deficits, regressing after reduction of the device suction. MATERIAL AND METHODS: We conducted a systematic PubMed-based research of the literature to study the variety and frequency of the reported symptoms from 1st of January 1980 until 1st of October 2015. RESULTS: Reviewing the literature 24 relevant citations including 27 reported cases of posttraumatic or postoperative loss of CSF leading to neurological symptoms were identified. All 15 reported cases in which a negative pressure suction device had been applied showed severe neurological and radiological symptoms such as coma or brain herniation and intracranial hemorrhage. In all cases patients recovered rapidly after removal of the suction device. Milder symptoms were observed in the patients without negative pressure suction, mainly only presenting with headaches or cranial nerve involvement.Additionally, we give an overview about current recommendations regarding cranial and spinal imaging to rule out dural laceration and cranial hypotension. CONCLUSION: Patients with dural laceration complicated by accidental drainage of CSF can present with life-threatening conditions. Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis. A precise radiological examination can help to rule out dural laceration and intracranial hypotension. KEY POINTS: • Undetected dural laceration complicated by negative pressure suction drains can induce life-threatening symptoms.• Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis for radiologists Citation Format: • Sporns PB, Schwindt W, Cnyrim CD et al. Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits. Fortschr Röntgenstr 2016; 188: 451 - 458.

Glioblastomas vs. lymphomas: more diagnostic certainty by using susceptibility-weighted imaging (SWI).

PURPOSE: It can be difficult to differentiate glioblastomas from lymphomas using only standard MR images. There are references suggesting that it might be possible to differentiate these tumors using susceptibility-weighted imaging (SWI). The purpose of this study is to prove the diagnostic benefit using susceptibility-weighted images. MATERIAL AND METHODS: Three neuroradiologists tried to differentiate 4 histologically verified lymphomas from 11 glioblastomas in retrospect. They first viewed the conventional MR images and declared a diagnosis with a grade of certainty. Afterwards they additionally reviewed the susceptibility-weighted images. RESULTS: Glioblastomas have a clearly higher grade of susceptibility signals than lymphomas. By additionally using susceptibility-weighted images, the radiologists determined the correct diagnosis in 82.2 % of the cases. Without susceptibility-weighted images, the diagnosis was correct in 75.5 % of the cases. The subjective gain of certainty was 16.5 %. If there were no intratumoral susceptibility signals (ITSS) (grade 1), the sensitivity for diagnosing a lymphoma was 70 % and the specificity was 100 %. The sensitivity for diagnosing a glioblastoma was 90.5 % and the specificity was 100 % if there was a high rate of intratumoral susceptibility signals (grade 3). CONCLUSION: Susceptibility-weighted images are an additional tool in clinical practice for determining the correct diagnosis. The differentiation between glioblastomas and lymphomas and the certainty of the determined diagnosis are better. Therefore, we recommend adding susceptibility-weighted imaging to the clinical MR tumor protocol.

Unilateral INO is associated with ocular tilt reaction in pontomesencephalic lesions: INO plus.

OBJECTIVE: Correlation of internuclear ophthalmoplegia (INO) with components of the ocular tilt reaction (OTR) in order to localize graviceptive (specifically otolithic) pathways in the brainstem. METHODS: We retrospectively analyzed data of 120 patients with INO (87 unilateral [9 of whom had one-and-a-half syndrome], 33 bilateral) for OTR (subjective visual vertical [SVV], ocular torsion, skew deviation) to localize causative brainstem lesions in MRI. RESULTS: Unilateral INO was accompanied by at least one component of OTR: SVV tilt in 96%, ocular torsion in 79%, and skew deviation in 50%. All components were directed to the contralesional side. Contralateral OTR occurred in 89% of patients with one-and-a-half syndrome. Only 9% of patients with bilateral INO exhibited OTR. MRI showed distinct lesions in 68%, which almost exclusively projected onto the pontomesencephalic medial longitudinal fascicle (96%). Follow-up measurements revealed SVV and ocular torsion normalized faster than the adduction deficit in INO. CONCLUSIONS: First, unilateral internuclear ophthalmoplegia (INO) is regularly associated with contraversive ocular tilt reaction (OTR): INO plus. Thus, graviceptive pathways join the medial longitudinal fascicle after crossing between the vestibular and abducens nuclei. Second, the different time course and degree of recovery of OTR components and INO signs can be explained by the hypothesis that vestibular tone imbalance is compensated by central vestibular adaptation mechanisms (probably driven mainly by cerebellar-vestibular projections), whereas impaired adduction is less susceptible to compensation according to Hering's law and can only be overcome by lesion repair. Third, bilateral INO is seldom associated with OTR, confirming that bilateral impairment of graviceptive pathways does not cause imbalance in roll plane.