Testing a premorbid cognitive deficit by a validated indirect evaluation method allowed us to verify that there was evidence of neurological compromise even before a clinical diagnosis or the completion of the first magnetic resonance imaging in patients who would then suffer from multiple sclerosis.

Purpose The use of susceptibility weighted imaging in high field magnetic resonance imaging scanners can detect the nigrosome-1 area located in the caudo-lateral region of the pars compacta in the substantia nigra. This structure comprises a significant amount of dopaminergic neurons and degenerates in the early stages of Parkinson’s disease. Essential tremor is a neurological condition that in some cases could be confused with the early stages of Parkinson’s disease with a possible error in clinical diagnosis. Our purpose is to evaluate the accuracy of nigrosome-1 detection by high resolution magnetic resonance imaging to discriminate Parkinson’s disease from essential tremor. Methods A case–control study compared patients with a clinical diagnosis of Parkinson’s disease and essential tremor. Magnetic resonance imaging studies were performed using a 3T magnetic resonance imaging scanner. The susceptibility weighted imaging sequence was obtained in the axial plane with an isotropic voxel of 0.75 mm. Two independent neuroradiologists evaluated the images without access to clinical patient data. Results Sixteen patients were included in each group (Parkinson’s disease and essential tremor). Average age: Parkinson’s disease group: 71.3 (SD 6.3) and essential tremor group: 68.3 (SD 12.3). For the first evaluator, the nigrosome-1 area was absent in 15 patients with Parkinson’s disease and in two with essential tremor and for the second evaluator was absent in 15 patients with Parkinson’s disease and four with essential tremor. The sensitivity/specificity for the diagnosis of Parkinson’s disease was 93.75%/87.5% for the first evaluator and 93.75%/75% for the second evaluator. Conclusion The detection of the nigrosome-1 area is a useful tool in the differential diagnosis between Parkinson’s disease and essential tremor, with high sensitivity and specificity.

The cerebellar flocculus is a critical structure involved in the control of eye movements. Both static and dynamic abnormalities of the vestibulo-ocular reflex (VOR) have been described in animals with experimental lesions of the flocculus/paraflocculus complex. In humans, lesions restricted to the flocculus are rare so they can become an exceptional model to contrast with the clinical features in experimental animals or in patients with more generalized cerebellar diseases. Here, we examined a 67-year-old patient with an acute vestibular syndrome due to an isolated infarct of the right flocculus. We evaluated him multiple times over 6 months-to follow the changes in eye movements and vestibular function-with caloric testing, video-oculography and head-impulse testing, and the anatomical changes on imaging. Acutely, he had an ipsilateral-beating spontaneous nystagmus, bilateral gaze-evoked nystagmus, borderline impaired smooth pursuit, and a complete contraversive ocular tilt reaction. The VOR gain was reduced for head impulses directed contralateral to the lesion, and there was also an ipsilesional caloric weakness. All abnormalities progressively improved at follow-up visits but with a considerable reduction in volume of the affected flocculus on imaging. The vestibular and ocular motor findings, qualitatively similar to a previously reported patient, further clarify the "acute floccular syndrome" in humans. We also add new information about the pattern of recovery from such a lesion with corresponding changes in the size of the affected flocculus on imaging.

ObjectiveOur aim was to determine whether overt catch up saccades (OS) provoked by vestibular stimuli, as observed in the video head impulse test (vHIT), have comparable metrics as visually triggered horizontal saccades (VS), indicating a common saccadic brainstem generator.MethodsThree groups of patients were studied: patients with neurological disorders causing slow saccades (group 1, n = 12), patients with peripheral vestibular lesions (group 2, n = 43), and normal controls (group 3, = 24). All patients underwent vHIT and Videooculographic testing. OS velocity, acceleration, amplitude and duration and VS velocity in this group was compared between the groups.ResultsThere was significant reduction in the velocity of visually guided saccades in group 1, as expected from the patient selection constraints of this study. Group 1 also exhibited saccades which were longer in duration and of reduced acceleration when compared to subjects without saccadic slowing to visual targets (Group 2 and 3). There were significant positive correlations between OS acceleration and amplitude in both normal saccade groups (2 and 3) which was not observed in the slow saccade group (1).ConclusionsThe metrics of overt saccades measured by the vHIT in patients with slow saccades and normal controls are similar to visually guided saccades. This supports the hypothesis that overt saccades associated with vestibular stimuli and visually triggered saccades share common circuitry that controls metrics.