Acute Onset Quadriplegia and Stroke: Look at the Brainstem, Look at the Midline

Acute onset quadriplegia with or without facial sparing is an extremely rare vascular syndrome, and the main focus of attention is on the cervical and upper thoracic spinal cord as the putative site of the damage. Quadriplegia has been occasionally reported in brainstem strokes within well-defined lesion patterns, but these reports have gained little attention so far because of the rarity of this clinical syndrome. The clinical, neuroanatomical and neuroimaging features of ischemic stroke locations associated with quadriplegia have been collected and reviewed in a pragmatical view, which includes a detailed description of the neurological signs associated with the damage of the pyramidal pathways. Two clinical examples have been added to raise practical suggestions in neurovascular practice. Ischemic stroke sites determining quadriplegia have some main well-defined midline locations in the brainstem, involving the pyramidal pathways of both sides in a single synchronous ischemic lesion in the medulla oblongata and in the pons. Several accompanying neurological signs have been described when the ischemic lesion involves tracts and nuclei other than the pyramidal pathways, and they can be useful as localizing clues. In some cases, the typical neuroimaging appearance of the ischemic lesion on Magnetic Resonance Imaging (MRI) has been reported as being a "heart appearance sign". This last sign has been described in midbrain strokes too, but this location is not associated with quadriplegia. The main etiology is atherothrombosis involving the intradural segment of the vertebral artery (VA) and their perforating branches. Two clinical examples of these rare vascular syndromes have been chosen to support a pragmatical discussion about the management of these cases. A midline ischemic stroke in the brainstem is a very rare vascular syndrome, and the acute onset quadriplegia is a distinctive feature of it. The awareness of this cerebrovascular manifestation might help to recognize and treat these patients.

[A Case of Bilateral Medial Medullary Infarction With Heart Appearance Sign]

We report a bilateral medial medullary infarction in which diffusion-weighted images revealed a unique configuration: a heart appearance sign. If it is early diagnosed, it might predict a poor outcome. An 85-year-old man developed dysarthria and numbness in his four limbs and was transferred to our hospital. Brain MR diffusion-weighted images revealed a high-intensity lesion in the bilateral medial medulla oblongata -- a heart appearance sign -- and we diagnosed a bilateral medial medullary infarction. Although his symptom changed aggressively for the worse, it finally changed for the better without bulbar paralysis, and he was transferred to another hospital for rehabilitation. When the medial medulla oblongata is supplied by the unilateral control of the anterior spinal artery, its occlusion can cause a bilateral medial medullary infarction.

[A case of bilateral medial medullary and left tegmentum of pontine infarction in whom DSA-MR fusion imaging identified infarct-relevant arteries]

We herein reported a patient with acute ischemic stroke in the bilateral medial medullary and the left tegmentum of the pons who presented with various neurological symptoms. Fusing digital subtraction angiography (DSA) and MRI (DSA-MR fusion imaging) could reveal the infarct-relevant arteries. A 41-year-old male presented with headache, bilateral arm's dysesthesia, quadriplegia, left Horner's syndrome, upbeat nystagmus, internuclear ophthalmoplegia and left peripheral facial paralysis. Diffusion weighted MRI (DWI) revealed the high intensity lesion in the bilateral medial medullary and the left tegmentum of the pons. MRA showed right vertebral artery (VA) occlusion. A high intensity on T₁ weighted imaging was shown on the right VA vessel wall. DSA-MR fusion imaging revealed the anterior spinal artery (ASA) occlusion proximal to the infarction. The stenosis was located at the origin of the right VA perforating branch distributing into the infarct lesion. The steno-occlusive lesion of ASA and VA perforating branch due to VA dissection resulted in infarction in the pontomedullary junction and caused various neurological symptoms. DSA-MR fusion imaging would prove the radiological anatomy of infarct-relevant arteries and clarify the etiology of ischemic stroke.

Treatment of Medial Medullary Infarction Using a Novel iNems Training: A Case Report and Literature Review

Objective. We describe the case of a 66-year-old Japanese male patient who developed medial medullary infarction along with severe motor paralysis and intense numbness of the left arm, pain catastrophizing, and abnormal physical sensation. We further describe his recovery using a new imagery neurofeedback-based multisensory systems (iNems) training method. Clinical Course and Intervention. The patient underwent physical therapy for the rehabilitation of motor paralysis and numbness of the paralyzed upper limbs; in addition, we implemented iNems training using EEG activity, which aims to synchronize movement intent (motor imagery) with sensory information (feedback visual information). Results. Considerable improvement in motor function, pain catastrophizing, representation of the body in the brain, and abnormal physical sensations was accomplished with iNems training. Furthermore, iNems training improved the neural activity of the default mode network at rest and the sensorimotor region when the movement was intended. Conclusions. The newly developed iNems could prove a novel, useful tool for neurorehabilitation considering that both behavioral and neurophysiological changes were observed in our case.

Conjugate Eye Deviation Caused by Upper Medial Medullary Infarction: A Case Report

Conjugate eye deviation (CED) is defined as a sustained shift in horizontal gaze toward 1 side, together with gaze failure to the other side, caused by lesions in the brainstem, basal ganglia, or cortical frontal eye fields. To date, very few reports have described CED in patients with medullary infarction. A 76-year-old woman presented with sudden onset of vertigo and right hemiparesis, accompanied by CED to the right with gaze palsy to the left. Her brain magnetic resonance imaging showed left upper medial medullary infarction involving the left nucleus prepositus hypoglossi (NPH) and adjacent to the left inferior olivary nucleus (ION). After treatments with 200 mg of aspirin and 60 mg of edaravone daily, symptoms gradually improved. The NPH and ION constitute NPH-ION-floccus-vestibular nucleus loop and contribute to the inhibitory mechanisms for horizontal eye movements. In addition, NPH projects excitatory neurons to the contralateral vestibular nucleus. In our case, disorders of the NPH and ION might have dysregulated inhibitory and excitatory projections, and thereby cause CED to the right with gaze palsy to the left. This represents a rare case showing CED to the contralesional side in upper medial medullary infarction.

Medial medullary infarction caused by antineutrophil cytoplasmic antibody-related vasculitis: Case report and review of the literature

RATIONALE

Medial medullary infarction accounts for less than 1% of brain infarctions, and medial medullary infarctions is very rarely caused by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis.

PATIENT CONCERNS

We report the case of a 76-year-old man at low risk of arteriosclerosis who presented with disorders on the left side including gaze-evoked nystagmus, paralysis of the extremities, pyramidal signs, sensory disturbance, and dysesthesia. Brain magnetic resonance imaging also showed right medial medullary infarction.

DIAGNOSES

Medial medullary infarction caused by ANCA-related vasculitis was diagnosed based on mild renal dysfunction and high levels of blood leukocytes, C-reactive protein (CRP), and myeloperoxidase (MPO)-ANCA.

INTERVENTIONS AND OUTCOMES

He underwent two 3-day courses of steroid pulse therapy involving daily 1000 mg doses of methylpredonine. He then received 30 mg/day (0.5 mg/kg/day) of prednisolone (PSL) without other immunosuppressants. Levels of MPO-ANCA and the inflammatory marker CRP decreased rapidly a month after admission. Once MPO-ANCA became undetectable, the PSL dose was carefully reduced to 10 mg/day. To treat his paralysis, we provided rehabilitation with a Hybrid Assistive Limb five times starting at a month post-onset. His Barthel index score rose from 45 to 70 points.

LESSONS

Medullary infarction is mostly caused by arteriosclerosis and vertebral arterial dissection. When systemic inflammatory findings are obtained, ANCA-associated vasculitis should be considered a potential cause, and steroid pulse therapy should be promptly administered.

Clinical Study of 27 Patients with Medial Medullary Infarction

BACKGROUND

Medial medullary infarction (MMI) is a rare ischemic stroke. Frequency of each neurological finding in MMI was different in each study.

METHODS

We retrospectively evaluated the medical records of patients with cerebral infarction who were admitted between March 1998 and October 2015. Patients in our study were diagnosed as having MMI by magnetic resonance image examination.

RESULTS

Of 2727 patients with ischemic stroke, 27 patients (20 males and 7 females) had MMI. The MMI was complicated by infarcts located in the pons (n = 6), cerebellum (n = 2), and lateral medulla (n = 1). One patient had bilateral MMI. Large-artery atherosclerosis was the most common etiology. Motor weakness of the extremities was the most common neurological finding. Diminished contralateral superficial sensation was more common than diminished contralateral vibratory sensation, and these 2 types of sensory disturbance were often complicated. The patients with large MMI significantly more often accompanied diminished touch (P = .003), pain (P = .017), and vibratory (P = .019) sensation. Facial weakness was shown more common contralateral to the infarcts than ipsilateral (n = 8 contralateral, n = 1 ipsilateral). Lingual palsy was also more common contralateral to the lesions (n = 3 contralateral, n = 1 ipsilateral). One patient alone fulfilled the classical Dejerine triad.

CONCLUSIONS

In MMI, motor weakness of extremities was commonly shown, and complication of diminished sensations indicated the large infarcts. As for facial weakness and lingual palsy, the supranuclear type was more prominent than the infranuclear type.

Abnormal vestibular evoked myogenic potentials in medial medullary infarction

Background

The medial vestibulospinal tract (MVST), which descends in the medial longitudinal fasciculus (MLF), may mediate the vestibular evoked myogenic potentials (VEMPs) in the contracting sternocleidomastoid muscle. We report herein abnormal VEMPs in a patient with medial medullary infarction (MMI) that appeared to involve the MLF.

Case Report

A patient with infarction involving the right medial medulla showed decreased p13-n23 amplitude and increased p13/n23 latencies of the VEMPs on the right side. These abnormal VEMPs recorded in an MMI patient support the theory that VEMPs are mediated by the MVST contained within the MLF.

Conclusions

VEMPs may represent a valuable tool for investigating vestibular dysfunction originating from the saccule, even in patients with central vestibulopathies, which is not readily defined by conventional vestibular function tests.