Isolated Cerebellar Nodular Infarction with Apogeotropic Central Paroxysmal Positional Nystagmus

No abstract available.

Isolated Nodular Ischemic Infarcts: A Central Lesion That Presents as Peripheral Vertigo.

Aims and Objective: Giddiness is one of the commonest presenting complaints to the emergency physicians. Differentiation between ‘peripheral’ and ‘central’ etiologies is important to avoid unnecessary investigations and avoid missing a potentially serious diagnosis such as an ischemic stroke. Isolated nodular infarction can present with clinical signs that mimic a peripheral vestibular cause. We present the clinical findings in 14 cases of isolated nodular infarction and discuss their differentiating features. Study Design: Retrospective case series. Place and Duration: Tertiary care university hospital in Singapore between January 2007 to September 2012. Methods: We evaluated the clinico-radiological findings of all the patients diagnosed with isolated nodular infarction at our center during the study period. Their clinical presentations were extracted from the case records. We combined our cases to an existing series of 8 patients from Korea to strengthen the findings. Results: Of the 286 acute posterior circulation ischemic stroke patients admitted to our tertiary care center during the study period, 6 (2.1%) were found to have isolated nodular infarction. They typically presented with acute severe giddiness. Nystagmus was seen in all, which was unidirectional and beating towards the side of the lesion with no latency or fatigability. Walking was usually severely impaired due to imbalance and all patients had a negative head impulse test. All patients at our center achieved complete recovery at 3- months. Conclusions: We present the clinical spectrum of isolated nodular infarction. In addition to a high index of suspicion in patients with multiple vascular risk factors, a negative head impulse test despite severe vertigo and imbalance can help in establishing the correct diagnosis.

A Case of Atypical Isolated Nodular Infarction: Nystagmus with a Reverse Direction / 대한뇌졸중학회지

A cerebral infarction involving the nodulus usually produce contralateral lateropulsion and ipsilateral spontaneous nystagmus to the lesion. Here, we report a case of atypical isolated nodular infarction showed ipsilateral lateropulsion and contralateral spontaneous nystagmus to the lesion with a normal head impulse test. A right-handed 70-year-old man developed sudden vertigo with an unsteady gait. Neurologic examination revealed spontaneous left-beating nystagmus with a torsional component. He also displayed imbalance of walking and axial lateropulsion to the right side. Head impulse test was normal. Magnetic resonance imaging indicated acute infarction in the right nodulus on diffusion-weighted images.

Tilt Suppression of the Post-rotatory Nystagmus in Cerebellar Nodular Lesions

BACKGROUND AND OBJECTIVES: Head tilt at the end of step rotation about a vertical axis decreases the time constant (TC) of the post-rotatory nystagmus, which is known as tilt-suppression of the vestibulo-ocular reflex (VOR). Tilt suppression of the VOR is mediated by the cerebellar nodulus and ventral uvula and is eliminated after surgical ablation of those structures. However, studies on the tilt suppression of the VOR have been sparse in humans with cerebellar lesions. MATERIALS AND METHODS:Five patients with circumscribed cerebellar lesions involving the nodulusor ventral uvula underwent recording of spontaneous and positional nystagmus, and the VOR. To evaluate tilt suppression of the VOR, the participants pitched their head forward at the end of step rotation about a vertical axis both in the clockwise and counter-clockwise directions. RESULTS: The VOR gain was increased in a patient with infarction in the territory of the medial posterior inferior cerebellar artery while the gain of visually enhanced VOR was normal in all the patients. The time constants of per- and post-rotatory nystagmus was increased in a patient with increased VOR gain and the tilt suppression of the post-rotatory nystagmus was impaired in two patients, either uni- or bilaterally. Spontaneous downbeat and central positional nystagmus were frequently accompanied. CONCLUSIONS: Nodular lesion may impair tilt suppression of the VOR. Measurement of tilt suppressive effect of the VOR may provide a valuable tool for evaluating the nodular dysfunction.

A Case of Isolated Cerebellar Nodulus Infarction with Periodic Alternating Nystagmus and Unilateral Vestibulopathy

We report a patient with an isolated cerebellar nodulus infarction who presented with periodic alternating nystagmus (PAN), perverted head-shaking nystagmus (pHSN), and loss of tilt suppression of the vestibulo-ocular reflex (VOR). Several days after the initial symptoms resolved, the patient also presented with purely vestibular syndrome with vertigo, spontaneous horizontal nystagmus without the usual signs of cerebellar dysfunction. The chain of those symptoms were ascribed to ischemia of the cerebellar nodulus.

Isolated nodular infarction and vestibular neuritis

An isolated nodular infarction presenting as an isolated vertigo with unidirectional, gaze-fixed nystagmus has not been previously reported. We reported a patient with cerebellar infarction who presented with purely isolated vertigo, ipsilesional, spontaneous nystagmus, and contralesional axial lateropulsion without usual symptoms or signs of cerebellar dysfunction. An MRI of the brain showed a small infarct selectively involving the nodulus. A pure vestibular syndrome in our patient may be explained by an ipsilateral involvement of nodulo-vestibular inhibitory projection to vestibular nucleus. Clinicians should be aware of the possibility of a nodulus infarction in patients with an acute vestibular syndrome, even if the pattern of nystagmus and lateropulsion is typical of vestibular neuritis.

Evaluation of Dual-energy Digital Subtraction Chest Radiography in Detection of Small Pulmonary Nodules / 实用放射学杂志

Objective To investigate the value of dual-energy digital subtraction chest radiography in detection of small pulmonarynodules.Methods CT scanning,dual-energy digital subtraction chest radiographs and routine digital chest radiographs were obtainedrespectively from 27 consecutive oncology patients with pulmonary metastasis.The image quality of these two kinds of DR by quality control phantom of Kodak was compared. The images of dual-energy digital subtract radiographs and the routine digital radiography were analysedby two radiologists in biblind method and the detecting rate of pulmonary metastasis by both DR was compared based on the results CTscanning. Results The quality of dual-energy digital subtraction chest radiographs is equal to the routine one except the definition. The detectable rate of pulmonary nodules by dual-energy digital subtraction chest radiographs was 91.2%, by the routine DR was 85.0%. There was significant difference (P