Internuclear ophthalmoplegia and cerebellar ataxia: report of one case

A rare case of unilateral Cogan's anterior internuclear ophthalmoplegia, upgaze palsy and ataxia caused by dorsal tegmentum lesion at pontomesencephalic junction

Background

Cogan’s anterior internuclear ophthalmoplegia (INO) is characterized by INO with inability to converge and commonly thought to be due to rostral midbrain lesion. A lesion outside midbrain that causes unilateral Cogan’s anterior INO combined with upgaze palsy and ataxia are rarely described.

Case presentation

A 67-year old male presented with left Cogan’s anterior internuclear ophthalmoplegia (INO), left appendicular ataxia and bilateral upgaze palsy. A Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA) brain showed a left dorsal tegmental infarct at the level of pontomesencephalic junction.

Conclusions

This case highlights the clinical importance of Cogan’s anterior INO in combination with upgaze palsy and ataxia, and report possible site of lesion in patients with such constellation. Clinicians should consider looking for cerebellar signs in cases of Cogan’s anterior INO, apart from just considering localizing the lesion at the midbrain.

Wernekink commissure syndrome secondary to a rare 'V'-shaped pure midbrain infarction: a case report and review of the literature

Purpose: Wernekink commissure syndrome is a typical but extremely rare mesencephalic syndrome, and generally presents with bilateral cerebellar dysfunction, diverse oculomotor disorders and occasionally delayed-onset palatal myoclonus or tremor. However, it has been reported infrequently.Methods: We report a case of a 55-year-old man who suffered an acute paramedian midbrain infarction presenting with bilateral cerebellar ataxia, bilateral anterior internuclear ophthalmoplegia and unilateral pseudoabducens palsy, which is confirmed as Wernekink commissure syndrome by magnetic resonance imaging (MRI). We summarized the clinical data of this entity and performed a literature review of 20 previous reports of patients with this syndrome.Results: In combination with previous reports, we found that the most common symptom was bilateral cerebellar ataxia (100%) and other frequent symptoms were oculomotor disorders (81%), delayed palatal myoclonus or tremor (33%) and consciousness dysfunction (33%). Lesions on brain MRI of all patients affected the area of caudal paramedian midbrain (CPM).Conclusion: Bilateral cerebellar ataxia and lesions involved in the area of CPM on MRI are the major features of Wernekink commissure syndrome and should be the necessary conditions of diagnostic criteria. The simultaneous occurrence of bilateral cerebellar ataxia and oculomotor disorders is significant for localization diagnosis. Consciousness dysfunction is also a relatively frequent symptom of this syndrome. Moreover, pseudoabducens palsy might be attributed to a midbrain lesion. Clinicians should be familiar with and early to recognize this unique syndrome to avoid misdiagnosis.

Diffusion Tensor Imaging in a Case of Pontine Bleeding Showing Hypertrophic Olivary Degeneration and Cerebellar Ataxia

We present diffusion tensor tractography (DTT) findings in a case of hypertrophic olivary degeneration (HOD) and cerebellar ataxia. A 56-year-old man presented with abnormal ataxic gait and dysarthria. MRI 5 months after onset showed chronic pontine hematoma and enlarged bilateral inferior olivary nuclei. DTT showed decreased volume of the bilateral central tegmental tract, in accordance with the conventional hypothesis that HOD is associated with neurologic insult to the Guillain-Mollaret triangle. The patient's cerebellar ataxia was speculated to be due to decreased decussating fibers of the superior cerebellar peduncle, and this was confirmed by DTT.

Wernekink commissure syndrome with palatal myoclonus at onset: a case report and review of the literature

Background

Wernekink commissure syndrome causes a peculiar combination of internuclear ophthalmoplegia, dysarthria, and delayed-onset palatal myoclonus. Palatal myoclonus is thought to be secondary to delayed hypertrophic degeneration of the bilateral inferior olivary nuclei secondary to involvement of bilateral dentatoolivary tract. We describe a case of a patient with early-onset palatal myoclonus.

Case presentation

A 53-year-old Caucasian man with several vascular risk factors presented to our emergency room with slurred speech, double vision, difficulty with swallowing and walking, and rhythmic contractions of the soft palate. Brain magnetic resonance imaging showed an acute infarct of the right caudal midbrain and an old infarct of the right medulla. We hypothesize that the cause of early palatal myoclonus in our patient was a two-hit mechanism with degeneration of the right olivary nucleus resulting from prior right medullary lacunar stroke with the new infarct affecting the dentato-rubro-olivary tract on the left side, causing bilateral dysfunction initiating palatal myoclonus.

Conclusions

Wernekink commissure syndrome with palatal myoclonus at onset suggests the presence of a prior ischemic insult in the medulla. Careful examination is important to identification of this presentation.

Wernekink Commissure Syndrome Secondary to Bilateral Caudal Paramedian Midbrain Infarction Presenting with a Unique "Heart or V" Appearance Sign: Case Report and Review of the Literature

Wernekink commissure syndrome secondary to caudal paramedian midbrain infarction (CPMI) is a rare midbrain syndrome involving the decussation of the superior cerebellar peduncle in the caudal paramedian midbrain tegmentum. The central characteristics are constant bilateral cerebellar dysfunction, variable eye movement disorders, and rare delayed palatal myoclonus. Following is a description of the case of a 60-year-old man who presented with dizziness, slurred speech, and difficulty walking. Neurological examination revealed bilateral cerebellar dysfunction and bilateral internuclear ophthalmoplegia (bilateral INO). Serial magnetic resonance imaging (MRI) revealed a lesion in the caudal paramedian midbrain with a "heart-shaped" sign on fluid-attenuation inversion recovery images and a "V-shaped" appearance on diffusion-weighted imaging (DWI). An acute CPMI with a "heart or V" appearance sign was diagnosed. Upon follow-up evaluation 3 months later, a palatal tremor accompanied by involuntary head tremor was discovered. Hypertrophy and increased signal of the bilateral inferior olivary nucleus, compatible with hypertropic olivary degeneration (HOD) were revealed during a subsequent MRI study.

[A case of midbrain infarction with acute bilateral cerebellar ataxia visualized by diffusion tensor imaging]

An 85-year-old woman with hypertension was admitted with a sudden onset of gait disturbance and dysarthria. On admission, the patient showed severe bilateral cerebellar ataxia with moderate right medial longitudinal fasciculus (MLF) syndrome. Magnetic resonance (MR) imaging showed an acute infarction in the lower and medial part of midbrain. Diffusion tensor imaging (DTI) started from both cerebellar peduncles revealed that the lesion of the acute infarction matched the decussation of superior cerebellar peduncle where crossing of tract was seen and a part of its tract was interrupted at the site. Interruption of the cerebellum red nuclear path at the medial part of midbrain was considered to be the reason for bilateral cerebellar ataxia and visualization of cerebellum red nuclear path by DTI can give better understanding of the neurological symptom.

Ischemic syndromes causing dizziness and vertigo

Dizziness/vertigo and imbalance are the most common symptoms of vertebrobasilar ischemia. Even though dizziness/vertigo usually accompanies other neurologic symptoms and signs in cerebrovascular disorders, a diagnosis of isolated vascular vertigo is increasing markedly by virtue of recent developments in clinical neurotology and neuroimaging. It is important to differentiate isolated vertigo of a vascular cause from more benign disorders involving the inner ear, since therapeutic strategies and prognosis differ between these two conditions. Over the last decade, we have achieved a marked development in the understanding and diagnosis of vascular dizziness/vertigo. Introduction of diffusion-weighted magnetic resonance imaging (MRI) has greatly enhanced detection of infarctions in patients with vascular dizziness/vertigo, especially in the posterior-circulation territories. However, well-organized bedside neurotologic evaluation is even more sensitive than MRI in detecting acute infarction as a cause of spontaneous prolonged vertigo. Furthermore, detailed evaluation of strategic infarctions has elucidated the function of various vestibular structures of the brainstem and cerebellum. In contrast, diagnosis of isolated labyrinthine infarction still remains a challenge. This diagnostic difficulty also applies to isolated transient dizziness/vertigo of vascular origin. Regarding the common nonlacunar mechanisms in the acute vestibular syndrome from small infarctions, individual strategies may be indicated to prevent recurrences of stroke in patients with vascular vertigo.

Ataxia and tremor due to lesions involving cerebellar projection pathways: a DTI tractographic study in six patients

Focal lesions of brainstem, thalamus, and subcortical white matter may cause movement disorders that are clinically indistinguishable from cerebellar symptoms. It is suspected that ataxia in these cases is due to damage of efferent or afferent pathways of the cerebellum. However, the precise anatomical correlate often remains undefined. We used deterministic diffusion tensor magnetic resonance imaging (DTI) tractography to study the anatomical relationship between lesions causing ataxia and efferent cerebellar pathways. Study subjects were six male patients with focal lesions of different etiology (demyelination, hemorrhage, ischemia, neoplasm) outside the cerebellum. Five patients had cerebellar-like ataxia with prominent contralateral upper limb involvement. One patient with an almost midline mesencephalic lesion had a symmetrical ataxic syndrome. We used 3T MRI (Intera, Philips Medical Systems, Best, Netherlands) and DTI tractography (32 directions, StealthViz DTI, Medtronic Navigation, Louisville, USA) to delineate the dentato-rubro-thalamo-cortical tract (DRT). In all patients, tractography demonstrated focal lesions affecting the DRT in different locations. We conclude that in vivo mapping of cerebral pathways using DTI tractography in patients with focal extracerebellar brain lesions may provide direct evidence of circumscribed damage to the DRT, causing unilateral cerebellar-like ataxia. Also, a unilateral mesencephalic lesion at the level of the crossing of the DRT may cause bilateral ataxia.

Internuclear ophthalmoplegia: causes and long-term follow-up in 65 patients

OBJECTIVES

To analyze the causes and long-term clinical outcome of internuclear ophthalmoplegia (INO) in a consecutive series of 65 patients.

PATIENTS AND METHODS

From a clinical registry of a neuroophthalmological department, patients with diagnosis of INO were retrospectively identified. Patients were classified into three groups: unilateral INO, bilateral INO, and one-and-a-half syndrome.

RESULTS AND CONCLUSIONS

Thirty-three men (50.8%) and 32 women (49.2%), with a mean age of 38.4 years were included in the study. INO was unilateral in 36 patients (55.4%), bilateral in 22 (33.8%) and one-and-a-half syndrome in seven (10.8%). The most common causes were vascular (36.9%), multiple sclerosis (32.3%), and infectious diseases (13.8%). Resolution of INO was documented in 32 patients (49.2%): 15 patients showed INO resolution during the first 3 months and 17 patients in 3-9 months. INO persisted in 33 patients (50.8%) even after a follow-up longer than 12 months.