Cerebellar infarction presenting with isolated positional vertigo: differentiating factors for benign paroxysmal positional vertigo

Neurological update: neuro-otology 2023

Much has changed since our last review of recent advances in neuro-otology 7 years ago. Unfortunately there are still not many practising neuro-otologists, so that most patients with vestibular problems need, in the first instance, to be evaluated and treated by neurologists whose special expertise is not neuro-otology. The areas we consider here are mostly those that almost any neurologist should be able to start managing: acute spontaneous vertigo in the Emergency Room-is it vestibular neuritis or posterior circulation stroke; recurrent spontaneous vertigo in the office-is it vestibular migraine or Meniere's disease and the most common vestibular problem of all-benign positional vertigo. Finally we consider the future: long-term vestibular monitoring and the impact of machine learning on vestibular diagnosis.

Initial symptoms of vertebrobasilar artery occlusions and the outcomes after endovascular treatment

BACKGROUND

Acute vertebrobasilar artery occlusion (VBAO) is a devastating disease in stroke patients. This study was aimed to identify the initial symptoms of patients with acute VBAO receiving endovascular treatment and determine its associations with clinical outcomes.

METHODS

Patients with VBAO receiving endovascular treatment at 21 stroke centres in China were recruited for this derivation cohort A data-driven approach of latent class analysis was applied to identify distinct symptom typologies of VBAO patients. Multivariable binary and ordinary logistic regressions were used to evaluate the associations between symptom subtypes and clinical outcomes.

RESULTS

A total of 548 patients were analysed in this study. Four distinct subgroups were defined: the vestibular symptom group (32.8%), anterior circulation mimic group (26.5%), non-specific symptom group (14.8%) and severe VBAO symptom group (25.9%). Compared with severe VBAO symptoms, non-specific symptoms were independently associated with higher rates of favourable outcome and functional independence at the 3 months [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.15-5.28; OR 3.46, 95% CI 1.54-7.79]and 1 year follow-up (OR 2.25, 95% CI 1.05-4.82; OR 2.69, 95% CI 1.22-5.92), and better functional improvement (shift in mRS score) at the 3 months (OR 2.05, 95% CI 1.15-3.67).

CONCLUSION

We identified four distinctive subtypes based on the initial symptoms of VBAO patients. Severe VBAO symptoms were associated with poor outcomes while non-specific and vestibular symptoms were indicators of a favourable outcome.

Central positional nystagmus: an update

Clinically, central positional nystagmus (CPN) is often suspected when atypical forms of its peripheral counterpart, i.e., benign paroxysmal positional vertigo (BPPV), are observed, namely a linear horizontal nystagmus as in horizontal canal BPPV or a downwardly and torsionally beating nystagmus as in anterior canal BPPV. Pathophysiologically, CPN is caused by cerebellar and/or brainstem dysfunction. Recent work has provided further insights into the different clinical phenotypes and the underlying pathomechanisms. We performed a PubMed review focused on the findings on CPN using the key words "Central Positional Nystagmus", "Central Positional Vertigo", "Positional Nystagmus" OR "Positioning Nystagmus" OR "Positional Vertigo" OR "Positioning Vertigo" AND "Central" from January 2015 to August 2021. CPN may account for up to 12% of patients with positional nystagmus. Clinical data on CPN are mostly based on case reports or small retrospective case series. CPN is frequently associated with cerebellar and/or brainstem structural lesions, namely stroke, tumours or demyelination, or diffuse involvement of these structures due to degenerative or autoimmune/paraneoplastic diseases; it is also found in patients with vestibular migraine. CPN can be paroxysmal or persistent. The direction of the nystagmus is often downward in head-hanging or apogeotropic in lateral supine positions; combinations of both forms also occur. Clinically it is important to note that CPN is often associated with other central, often cerebellar ocular motor or other neurological signs; typically, it is not improved by the therapeutic liberatory manoeuvres for BPPV. These additional features are also important for the diagnosis, in particular if no structural lesions are found. Pathophysiologically, CPN is believed to reflect an abnormal integration of semicircular canal-related signals by the cerebellar nodulus, uvula and/or tonsil, ultimately providing an erroneous estimation of the head tilt and/or eye position coordinates. The natural course of CPN remains, so far, largely unknown. Symptomatic treatment of CPN consists of pharmacotherapy, e.g., with 4-aminopyridine, and causative treatment of the underlying disease if known. CPN is an important differential diagnosis to BPPV and a clinically relevant entity with heterogenous clinical presentations and various pathomechanisms and etiologies. In particular, studies on the natural course and treatment of CPN are needed.