The efficacy and mechanism of theta burst stimulation for the relief of dysphasia after a stroke / 中华物理医学与康复杂志

Objective:To observe any effect of intermittent theta burst stimulation (iTBS) of the cerebellum on swallowing dysfunction after cerebellar infarction, and to explore its mechanism.Methods:Sixty-two cerebellar stroke survivors with dysphagia were randomly divided into an observation group and a control group, each of 29. In addition to the routine swallowing rehabilitation training, the observation group was treated with iTBS, while the control group was given sham iTBS. The incubation and amplitude of the bilateral suprahyoid muscle motor evoked potential (MEP) were recorded before and after 4 weeks of treatment. The exponential approximate entropy (ApEn) of different brain regions was compared between the two groups during reflex and autonomous swallowing. Swallowing function was evaluated using the penetration-aspiration scale (PAS).Results:MEP incubation in the bilateral suprahyoid muscles had decreased significantly after 4 weeks of treatment in the observation group, and the MEP amplitude in the bilateral suprahyoid muscles of the two groups had increased significantly. The average improvement in the amplitude and incubation in the observation group was significantly greater than in the control group. The average ApEn at C3, C4, P3, P4, T5 and T6 had increased significantly in both groups during both reflex and spontaneous swallowing, with the improvement in the observation group significantly greater. Swallowing function had improved significantly in both groups, but the average PAS grade of the observation group was again significantly better.Conclusions:iTBS can improve the swallowing function of dysphagic cerebellar stroke survivors. This may be due to iTBS improving the excitability of the cerebral cortex and improving motor control of the swallowing muscles.

Neuro-Otological Aspects of Cerebellar Stroke Syndrome

Cerebellar stroke is a common cause of a vascular vestibular syndrome. Although vertigo ascribed to cerebellar stroke is usually associated with other neurological symptoms or signs, it may mimic acute peripheral vestibulopathy (APV), so called pseudo-APV. The most common pseudo-APV is a cerebellar infarction in the territory of the medial branch of the posterior inferior cerebellar artery (PICA). Recent studies have shown that a normal head impulse result can differentiate acute medial PICA infarction from APV. Therefore, physicians who evaluate stroke patients should be trained to perform and interpret the results of the head impulse test. Cerebellar infarction in the territory of the anterior inferior cerebellar artery (AICA) can produce a unique stroke syndrome in that it is typically accompanied by unilateral hearing loss, which could easily go unnoticed by patients. The low incidence of vertigo associated with infarction involving the superior cerebellar artery distribution may be a useful way of distinguishing it clinically from PICA or AICA cerebellar infarction in patients with acute vertigo and limb ataxia. For the purpose of prompt diagnosis and adequate treatment, it is imperative to recognize the characteristic patterns of the clinical presentation of each cerebellar stroke syndrome. This paper provides a concise review of the key features of cerebellar stroke syndromes from the neuro-otology viewpoint.

Diagnostic Yield of Emergency Brain Magnetic Resonance Imaging in the Evaluation of Patients with Acute Dizziness in a University Hospital

BACKGROUND: Dizziness is one of the most common neurological symptoms for visiting the emergency department. Acute vertigo and severe imbalance may be the only presenting features of cerebellar stroke that could masquerade as a peripheral vestibular lesion. Magnetic resonance images (MRI) proved to be very sensitive in detecting acute stroke involving brainstem or cerebellum. In this retrospective study, we investigated the diagnostic yield of emergency brain MRI among the patients who visited emergency department with acute dizziness. METHODS: We reviewed the medical records of consecutive patients with acute dizziness who were seen in emergency department of Cheju National University Hospital between May 2005 and Oct 2006. We collected following the information from medical records. (1) Age, sex, and blood pressure at emergency department (2) Type, duration, accompanying symptoms of dizziness and positive finding from neurological and neuro-otological examination (3) Vascular risk factors (4) Results of MRIs. RESULTS: During the study period, 360 patients visited emergency department due to isolated acute dizziness. Emergent MRIs were performed in 84 (23.3%) patients. Although about 90% of them were older than 50 years and 60% of them had at least one or more vascular risk factors, central causes of dizziness were found in only five patients including four acute cerebellar infarctions and a cerebellar hemorrhage. Diagnostic yield of emergent MRI was only 6%. CONCLUSIONS: In this study, emergency brain MRIs showed limited diagnostic yield among patients who visited emergency department with acute isolated dizziness.