Pontine Lesions Research Articles

Isolated abducens nucleus syndrome due to pontine tegmentum infarction

Introduction: Abnormalities of horizontal gaze could be caused by damage of the abducens nucleus due to ischemic lesion. We report a patient with isolated horizontal gaze palsy as a result of a small ischemic lesion of the pontine tegmentum. Observation: A 61-year-old man, with medical history of diabetes mellitus, dyslipidemia and high blood pressure, was hospitalized after 12 hours of transient dizziness and diplopia. On examination, he had conjugate eye deviation to the right side with horizontal gaze paralysis toward controlateral side. Vertical eye movements, convergence and pupillary reflex were preserved with no peripheral facial palsy. Brain MRI revealed a small lesion in the left pontine tegmentum. Patient received aspirin with atorvastatin and the gaze palsy has been disappeared three weeks later. Discussion: Conjugate lateral eye movement paralysis is commonly attributed to lesions of the caudal pons involving the abducens nucleus. horizontal gaze palsy is often associated to an ipsilateral peripheral facial palsy. In our case, the left lateral gaze palsy was isolated. The pontine lesion should be strictly confined the abducens nucleus which is extremely rare. the outcome of eye movement deviation in brainstem lesions is favorable within few weeks. Conclusion: Our case provides evidence that small pontine lesions can damage the abducens nerve nucleus without causing ipsilateral peripheral facial palsy.

Optimal access route for pontine cavernous malformation resection with preservation of abducens and facial nerve function.

The aim of this study was to analyze the differences between posterolateral and posteromedial approaches to pontine cavernous malformations (PCMs) in order to verify the hypothesis that a posterolateral approach is more favorable with regard to preservation of abducens and facial nerve function. The authors conducted a retrospective analysis of 135 consecutive patients who underwent microsurgical resection of a PCM. The vascular lesions were first classified in a blinded fashion into 4 categories according to the possible or only reasonable surgical access route. In a second step, the lesions were assessed according to which approach was performed and different patient groups and subgroups were determined. In a third step, the modified Rankin Scale score and the rates of permanent postoperative abducens and facial nerve palsies were assessed. The largest group in this series comprised 77 patients. Their pontine lesion was eligible for resection from either a posterolateral or posteromedial approach, in contrast to the remaining 3 patient groups in which the lesion location already had dictated a specific surgical approach. Fifty-four of these 77 individuals underwent surgery via a posterolateral approach and 23 via a posteromedial approach. When comparing these 2 patient subgroups, there was a statistically significant difference between postoperative rates of permanent abducens (3.7% vs 21.7%) and facial (1.9% vs 21.7%) nerve palsies. In the entire patient population, the abducens and facial nerve deficit rates were 5.9% and 5.2%, respectively, and the modified Rankin Scale score significantly decreased from 1.6 ± 1.1 preoperatively to 1.0 ± 1.1 at follow-up. The authors' results suggest favoring a posterolateral over a posteromedial access route to PCMs in patients in whom a lesion is encountered that can be removed via either surgical approach. In the present series, the authors have found such a constellation in 57% of all patients. This retrospective analysis confirms their hypothesis in a large patient cohort. Additionally, the authors demonstrated that 4 types of PCMs can be distinguished by preoperatively evaluating whether only one reasonable or two alternative surgical approaches are available to access a specific lesion. The rates of postoperative sixth and seventh nerve palsies in this series are substantially lower than those in the majority of other published reports.

Suspected pontine and extra‐pontine myelinolysis in a cat

AbstractA 4.5‐year‐old neutered female domestic shorthair cat was presented with an acute onset of neurological signs suggestive of multifocal or diffuse intracranial lesions. MRI of the head revealed bilaterally symmetrical T2‐weighted hyperintensities in the pons and thalamus, suggestive of a metabolic or toxic aetiology. The pontine lesion on MRI resembled what in humans is known as the ‘trident sign’ reported in cases of pontine myelinolysis. Ancillary cerebrospinal fluid analysis revealed albuminocytologic dissociation and suspected myelin debris. No specific cause was identified, but the cat recovered over the next few weeks with only supportive therapy.

The clinical and cognitive spectrum of locked-in syndrome: 1-year follow-up of 100 patients.

In patients with locked-in syndrome (LIS), it is not known exactly to what extent cognitive functions are preserved and it is not known exactly how much it has improved. We aimed to examine the clinical and cognitive features of LIS 1 year after stroke. One hundred patients with locked-in syndrome (LIS) were recruited between January 2008 and May 2019 among 8200 patients with ischemic stroke. Patients were classified into two groups as single pontine infarcts (n = 72), and pontine plus multiple ischemic lesions (PMIL) (n = 28). Since the patients had limited motor and verbal response, the cognitive status of the patients in the early and late stages was evaluated with the Short Neuropsychological Questionnaire for Disabled Patients (SNQDP) test. At the onset of stroke, orientation to time and place was normal in 43% of patients with a single infarct compared with 18% of those with PMIL (OR 3.48; 95% CI 1.10-10.18; P = 0.015). There was no sustained visual fixation or tracking in 53% of patients with a single pontine infarct and 82% of those with PMIL (OR 4.12; 95% CI 1.41-12.02; P = 0.005). After 1-year follow-up, there was significant difference between patients with a single infarct and those with PMIL regarding to perception and execution, especially complex command follow (P = 0.042), attention span and concentration (P = 0.30), intelligible verbalization (P = 0.022). There was relatively high incidence (24%) of patients with a "good outcome" (mRS = 3) in those with single infarct. Given as in our study that many patients can show significant improvement in LIS, we recommend aggressive supportive measures, intense physical, speech and cognitive therapy to facilitate interaction with others and the environment.

Endoscopic Endonasal Transclival Approach to Ventral Pontine Cavernous Malformation: Case Report.

Ventral medial pontine cavernous malformations are challenging due to the location in eloquent tissue, surrounding critical anatomy, and potential symptomatic bleeding. Conventional approaches, such as anterolateral, lateral and dorsal approach, are associated with high risk of deleterious consequences due to excessive traction and damage to the surrounding tissues. The authors present an endoscopic endonasal approach for the resection of midline ventral pontine cavernous malformations, which follows principles of optimal access to brainstem cavernous malformations as the “two-point method.” No CSF leak or any other complications are obtained. The successful outcomes indicate that an individualized approach should be chosen before the surgery for brainstem cavernous malformations. With the advance of techniques, endoscopic endonasal approach could provide the most direct route to ventral pontine lesions with safety and efficiency.

Central pontine myelinolysis secondary to rapid correction of hyponatremia historical perspective with Doctor Robert Laureno.

Central pontine myelinolysis (CPM) is a neurological disorder characterized by damage to the myelin and oligodendrocytes in the pons.This review focuses on the history of CPM and the discovery of its association with the treatment of hyponatremia. The author reviewed original publications regarding CPM, hyponatremia, and the treatment of hyponatremia. The author interviewed Dr. RobertLaureno who was a pioneer in CPM research with his animal work in dogs. Animal models demonstrated the role of the rapid correction of hyponatremia as causative of pontine and extrapontine myelinolytic lesions. Nevertheless, the importance of the speed of correction was widely denied. There were years of debates and only slow changes in expert guidelines. CPM occurs as a consequence of a rapid rise in serum sodium in individuals with chronic hyponatremia. It is recommended to increase plasmasodium concentration by no more than 8 to 10 mmol/L per 24 h in chronic hyponatremia.

Hyponatremia, osmotic demyelination syndrome, and the importance of the patient’s history

Central pontine myelinolysis (CPM), first described in 1959, is a symmetrical non-inflammatory demyelinating disease with loss of oligodendrocytes that occurs most often following a rapid correction of severe hyponatremia (i.e., <120 mmol/L). It presents as a biphasic disease with initial seizure or encephalopathy, followed by clinical improvement and subsequent rapid deterioration with bulbar dysfunction, oculomotor dysfunction, various degree of paresis, and even locked in syndrome. Its occurrence is rare (≈0.6% of severe hyponatremia), it is diagnosed clinically and confirmed with brain imaging, ideally with magnetic resonance image, and it is reversible in approximately half the patients. Lesions are classically identified in the pons but extra pontine lesions (in basal ganglia, cerebellar white matter, thalamus, and hippocampus) have also been identified. The most commonly accepted molecular mechanism involves brain cell volume regulation with a rapid shift of osmole following brain edema which establishes during the chronic hyponatremic phase. For these reasons, osmotic demyelination syndrome (ODS) is a better term. The most identified risk factor is severe hyponatremia, but other electrolyte abnormalities can contribute, in particular, if the patient is an alcoholic or malnourished. This diagnosis should also be suspected in post-op patients with nausea and headache non-responsive to antiemetic and analgesic drugs. An essential step is an appropriate medical history, a list of medications, physical examination, and basic initial lab tests with the goal of identifying possible easily reversible causes of hyponatremia. Correction of severe hyponatremia with neurological symptoms should be done using rapid boluses of hypertonic saline solution in rapid succession with goals of increasing serum sodium by 5-6 mEq/L in the first two hours, which should be stopped if the level has risen by 10 mEq/L in the first five hours, and with the overall correction goal not to exceed 15-20 mEq/L in 48 hrs. This method has been shown safe in all hospital settings studied. Serial measurements of electrolyte levels and neurological examinations are recommended, as are correction of all electrolyte abnormalities, in
 particular magnesium and potassium. Thiamine should be given to all patients with chronic alcohol use who present with hyponatremia and encephalopathy.

DIPG-23. SINGLE CASE REPORT OF LOW DOSE RADIOTHERAPY AND CHEMOTHERAPY IN THE TREATMENT OF DIPG

A 3 year-old girl, was noted to have progressive gait problem since Nov. 2017 and brought to hospital for checkup. Brain MRI on Jan. 2018 showed T2 hyperintensity infiltrative pontine lesion, favoring diffuse infiltrative pontine glioma and mild obstructive hydrocephalus, received VP-shunting on Jan. 15, 2018. Due to the refusal of surgical biopsy for tissue proof, we started the radiotherapy from Jan. 24, 2018, using Rapidarc technique with 6MV photon energy to treat the brain stem lesion, ended on Feb. 24, 2018 with total dose of 25.5Gy in 17 fractions as our usual practice. Following the completion of radiotherapy, we started the adjuvant chemotherapy using 1-week on, 1-week off regimen of temozolomide using dosage of 75 mg/sq-m/day, and this patient’s general condition returned back to nearly normal. Serial follow-up images of brain MRI on 04/30/2018, 08/01/2018, 11/30/2018, 02/26/2019, 05/30/2019, 08/28/2019 showed slow progression of the pontine lesion, without the development of contrast enhanced new lesion. She maintained the functional independent until Sep. 2019, she was noted to have symptoms of ataxic gait, esotropia and choking on drinking liquid. We started the retreatment of radiotherapy from Oct.7, 2019, using same technique, ended on Nov. 5, 2019 with total dose of 30Gy in 20 fractions. The symptoms improved partially after the treatment, with residual weakness over left extremity. We are still treating the patient with adjuvant temozolomide, and she has survived most of time functionally independent in these 2 years.

Brainstem trigeminal fiber microstructural abnormalities are associated with treatment response across subtypes of trigeminal neuralgia.

Neurosurgical treatments for trigeminal neuralgia (TN) can provide long-lasting pain relief; however, some patients fail to respond and undergo multiple, repeat procedures. Surgical outcomes can vary depending on the type of TN, but the reasons for this are not well understood. Neuroimaging studies of TN point to abnormalities in the brainstem trigeminal fibers; however, whether this is a common characteristic of treatment nonresponse across different subtypes of TN is unknown. Here, we used diffusion tensor imaging (DTI) to determine whether the brainstem trigeminal fiber microstructure is a common biomarker of surgical response in TN and whether the extent of these abnormalities is associated with the likelihood of response across subtypes of TN. We studied 98 patients with TN (61 classical TN, 26 TN secondary to multiple sclerosis, and 11 TN associated with a solitary pontine lesion) who underwent neurosurgical treatment and 50 healthy controls. We assessed treatment response using pain intensity measures and examined microstructural features by extracting pretreatment DTI metrics from the proximal pontine segment of the trigeminal nerves. We found that microstructural abnormalities in the affected pontine trigeminal fibers (notably, lower fractional anisotropy and higher radial diffusivity) highlight treatment nonresponders (n = 47) compared with responders (n = 51) and controls, and that the degree of abnormalities is associated with the likelihood of surgical response across subtypes of TN. These novel findings demonstrate the value of DTI as an objective, noninvasive tool for the prediction of treatment response and elucidate the features that distinguish treatment responders from nonresponders in the TN population.

Association of outcomes in acute flaccid myelitis with identification of enterovirus at presentation: a Canadian, nationwide, longitudinal study

Acute flaccid myelitis (AFM) is characterised by rapid onset of limb weakness with spinal cord grey-matter abnormalities on MRI scan. We aimed to assess whether detection of enterovirus in respiratory or other specimens can help predict prognosis in children with AFM. In this nationwide, longitudinal study, we evaluated the significance of detection of enterovirus in any sample in predicting outcomes in a cohort of Canadian children younger than 18 years presenting with AFM to tertiary paediatric hospitals in Canada in 2014 and 2018. All patients fulfilled the 2015 US Centers for Disease Control and Prevention case definition for definite AFM or probable AFM. Clinical data, laboratory findings, treatment, and neuroimaging results were collected (follow up period up to 5 years). We assessed neurological function and motor outcomes using Kurtzke's Expanded Disability Status Scale (EDSS) and a Weakest Limb Score. 58 children with AFM (median age 5·1 years, IQR 3·8-8·3) were identified across five of Canada's ten provinces and three territories. 25 (43%) children had enterovirus detected in at least one specimen: 16 (64%) with EV-D68, two (8%) with EV-A71, two (8%) with coxsackievirus, 10 (40%) with untyped enterovirus. Children who were enterovirus positive were more likely than those that were negative to have had quadriparesis (12 [48%] of 25 vs four [13%] of 30; p=0·028), bulbar weakness (11 [44%] of 25 vs two [7%] of 30; p=0·028), bowel or bladder dysfunction (14 [56%] of 25 vs seven [23%] of 30; p=0·040), cardiovascular instability (nine [36%] of 25 vs one [3%] of 30; p=0·028), and were more likely to require intensive care unit admission (13 [52%] of 25 vs 5 [17%] of 30; p=0·028). On MRI, most children who were enterovirus positive showed brainstem pontine lesions (14 [61%] of 23), while other MRI parameters did not correlate with enterovirus status. Median EDSS of enterovirus positive (EV+) and enterovirus negative (EV-) groups was significantly different at all timepoints: baseline (EDSS 8·5, IQR 4·1-9·5 vs EDSS 4·0, IQR 3·0-6·0; p=0·0067), 3 months (EDSS 4·0, IQR 3·0-7·4 vs EDSS 3·0, IQR 1·5-4·3; p=0·0067), 6 months (EDSS 3·5, IQR 3·0-7·0 vs EDSS 3·0, IQR 1·0-4·0; p=0·029), and 12 months (EDSS 3·0, IQR 3·0-6·9 vs EDSS 2·5 IQR 0·3-3·0; p=0·0067). Kaplan-Meier survival analysis of a subgroup of patients showed significantly poorer motor recovery among children who tested positive for enterovirus than for those who tested negative (p=0·037). Detection of enterovirus in specimens from non-sterile sites at presentation correlated with more severe acute motor weakness, worse overall outcomes and poorer trajectory for motor recovery. These results have implications for rehabilitation planning as well as counselling of families of children with these disorders. The findings of this study support the need for early testing for enterovirus in non-CNS sites in all cases of AFM. None.

Brainstem lesions are associated with sleep apnea in multiple sclerosis.

BackgroundStudies linking MRI findings in MS patients with obstructive sleep apnea severity are limited.ObjectiveWe conducted a retrospective study to assess MRI abnormalities associated with obstructive sleep apnea (OSA) in patients with multiple sclerosis (MS).MethodsWe performed retrospective chart review of 65 patients with multiple sclerosis who had undergone polysomnography (PSG) for fatigue as well as brain MRI. We measured the number of lesions in the brainstem and calculated the standardized third ventricular width (sTVW) as a measure of brain atrophy, and subsequently performed correlation analyses of the apnea-hypopnea index (AHI) with brainstem lesion location, sTVW, and Expanded Disability Status Scale (EDSS).ResultsMS Patients with OSA were significantly older and had a higher body mass index (BMI) and higher AHI measures than patients without OSA. After adjustment for covariates, significant associations were found between AHI and lesion burden in the midbrain (p < 0.01) and pons (p = 0.05), but not medulla.ConclusionsMidbrain and pontine lesions burden correlated with AHI, suggesting MS lesion location could contribute to development of OSA.

Retrosigmoid Approach for Resecting a Giant Lateral Pontine Ependymoma: Two-Dimensional Operative Video.

Ependymoma is one of the most common pediatric tumors in central nervous system, for which gross total resection has been the most favorable prognostic factor. 1 2 However, surgery of ependymomas located in brain stem is significantly challenging. This video demonstrates the microsurgical removal of an ependymoma originating from ependymal cells of the lateral recess of fourth ventricle via retrosigmoid approach in an 11-year-old female. The patient presented with a 6-month history of continues headache and vomiting. On examination, she had a walking instability and an emaciated body. Neuroimaging revealed a right lateral pontine lesion extending to the cerebellopontine angle region. The patient underwent a suboccipital craniotomy, followed by excellent exposure for the tumor. Petrosal vein encased by the tumor mass and close adhesion of the tumor and the initial segments of facial and acoustic nerves adjoined brain stem could be seen operatively. While preserving trigeminal nerve, facial and acoustic nerves, posterior cranial nerves, anterior inferior cerebellar artery, labyrinth artery, posterior inferior cerebellar artery, and petrosal vein, gross total resection was achieved under the careful operation along arachnoid spaces together with intratumoral decompression. The patient tolerated the procedure well without any neurological deficits. Histological examination confirmed the tumor as an ependymoma (WHO II). The cytology measurement of the cerebrospinal fluid did not find any tumor cells. Postoperative computed tomography and magnetic resonance imaging scan depicted complete resection of the tumor, and adjuvant radiotherapy was recommended. She remained symptom-free without any evidence of recurrence during the follow-up period of 1 year. Informed consent was obtained from the patient. The link to the video can be found at: https://youtu.be/sZ9GhUeltwc .

The role of pontine lesion location in differentiating multiple sclerosis from vascular risk factor-related small vessel disease

Background: Differentiating multiple sclerosis (MS) from vascular risk factor (VRF)-small vessel disease (SVD) can be challenging. Objective and Methods: In order to determine whether or not pontine lesion location is a useful discriminator of MS and VRF-SVD, we classified pontine lesions on brain magnetic resonance imaging (MRI) as central or peripheral in 93 MS cases without VRF, 108 MS patients with VRF and 43 non-MS cases with VRF. Results: MS without VRF were more likely to have peripheral pons lesions (31.2%, 29/93) than non-MS with VRF (0%, 0/43) (Exp(B) = 29.8; 95% confidence interval (CI) = (1.98, 448.3); p = 0.014) but there were no significant differences regarding central pons lesions between MS without VRF (5.4%, 5/93) and non-MS with VRF patients (16.3%, 7/43) (Exp(B) = 0.89; 95% CI = (0.2, 3.94); p = 0.87). The presence of peripheral pons lesions discriminated between MS and VRF-SVD with 100% (95% CI = (91.8, 100)) specificity. The proportion of peripheral pons lesions in MS with VRF (30.5%, 33/108) was similar to that seen in MS without VRF (31.2%, 29/93, p = 0.99). Central lesions occurred in similar frequency in MS with VRF (8.3%, 9/108) and non-MS with VRF (16.3%, 7/43, p = 0.15). Conclusion: Peripheral pons lesion location is a good discriminator of MS from vascular lesions.

Pontine gliomas a 10-year population-based study: a report from The Canadian Paediatric Brain Tumour Consortium (CPBTC).

Diffuse intrinsic pontine gliomas (DIPG) are midline gliomas that arise from the pons and the majority are lethal within a few months after diagnosis. Due to the lack of histological diagnosis the epidemiology of DIPG is not completely understood. The aim of this report is to provide population-based data to characterize the descriptive epidemiology of this condition in Canadian children. A national retrospective study of children and adolescents diagnosed with DIPG between 2000 and 2010 was undertaken. All cases underwent central review to determine clinical and radiological diagnostic characteristics. Crude incidence figures were calculated using age-adjusted (0-17year) population data from Statistics Canada. Survival analyses were performed using the Kaplan-Meier method. A total of 163 patients with pontine lesions were identified. Central review determined one-hundred and forty-three patients who met clinical, radiological and/or histological criteria for diagnosis. We estimate an incidence rate of 1.9 DIPG/1,000,000 children/year in the Canadian population over a 10years period. Median age at diagnosis was 6.8years and 50.3% of patients were female. Most patients presented with cranial nerve palsies (76%) and ataxia (66%). Despite typical clinical and radiological characteristics, histological confirmation reported three lesions to be low-grade gliomas and three were diagnosed as CNS embryonal tumor not otherwise specified (NOS). Our study highlights the challenges associated with epidemiology studies on DIPG and the importance of central review for incidence rate estimations. It emphasizes that tissue biopsies are required for accurate histological and molecular diagnosis in patients presenting with pontine lesions and reinforces the limitations of radiological and clinical diagnosis in DIPG. Likewise, it underscores the urgent need to increase the availability and accessibility to clinical trials.

Robotic Surgical Assistant (ROSA™) Rehearsal: Using 3-Dimensional Printing Technology to Facilitate the Introduction of Stereotactic Robotic Neurosurgical Equipment.

The use of frameless stereotactic robotic technology has rapidly expanded since the Food and Drug Administration's approval of the Robotic Surgical Assistant (ROSA™) in 2012. Although the safety and accuracy of the ROSA platform has been well-established, the introduction of complex robotic technology into an existing surgical practice poses technical and logistical challenges particular to a given institution. To better facilitate the integration of new surgical equipment into the armamentarium of a thriving pediatric neurosurgery practice by describing the use of a three-dimensional (3D)-printed patient model with in situ 3D-printed tumor for presurgical positioning and trajectory optimization in the stereotactic biopsy of a pontine lesion in a pediatric patient. A 3D model was created with an added silicone mock tumor at the anatomical position of the lesion. In a preoperative rehearsal session, the patient model was pinned and registered using the ROSA platform, and a mock biopsy was performed targeting the in Situ silicone tumor. Utilization of the 3D-printed model enabled workflow optimization and increased staff familiarity with the logistics of the robotic technology. Biopsy trajectory successfully reached intralesional tissue on the 3D-printed model. The rehearsal maneuvers decreased operative and intubation time for the patient and improved operative staff familiarity with the robotic setup. Use of a 3D-printed patient model enhanced presurgical positioning and trajectory planning in the biopsy of a difficult to reach pontine lesion in a pediatric patient. The ROSA rehearsal decreased operative time and increased staff familiarity with a new complex surgical equipment.

Stroke scan agnosia – What radiologists may not see

ObjectiveNeuroimaging helps neurologists make accurate diagnoses. We used a multidisciplinary review system to search for perceptual discrepancies in stroke lesions. We sought to identify recurrent pitfalls in the detection of neuroimaging stroke lesions. Patients and methodsPatients were selected from a neuroimaging database of second opinions if cerebrovascular lesions had been missed at initial reporting. Patient demographics, scanning modality and stroke type were recorded. ResultsA neuroradiologist second opinion was provided for 1336 patients. Forty-four patients, 18 women and 26 men, mean age 59.9 (SD 14.2) years, were identified in whom a vascular lesion was not detected on initial reporting. The lesions included cerebellar infarcts in 17 patients (bilateral in 7), pontine infarction/ischaemia (n=5), pontine and cerebellar lesions (n=1) and spinal infarction (n=1). Supratentorial infarction occurred in 10 patients of which 3 were thalamic infarcts. Vessel abnormalities were present in 8 patients (hyperdense vessel n=3, dissection n=3, middle cerebral artery occlusion on CTA n=1 and cerebral venous sinus thrombosis n=1). Convexity subarachnoid hemorrhage was missed and a subdural hematoma was not identified in one patient. In 10 (23 %) patients the missed lesions occurred solely on CT brain scanning. The missed lesions were symptomatic in 28 (64 %) patients and presentations were acute in 14 (32 %) patients. ConclusionSome cerebrovascular lesions are prone to perceptual errors with CT and MRI brain scanning. Radiologists and neurologists should be aware that posterior fossa lesions (particularly in the cerebellum and pons) and hyperdense vessel signs may be missed. Better identification of radiological cerebrovascular lesions should enhance management of acute and chronic stroke patients.

A Case Report: Isolated Pontine Lesion in Hypertensive of a Pregnant Patient with Idiopathic Thrombocytopenia

Posterior reversible encephalopathy syndrome (PRES) is a neuroradiologic diagnosis characterised by headache, seizures, altered mental status, and a spectrum of visual deficits ranging from visual neglect to cortical blindness. PRES manifestation is a situation of medical emergency; however, it is a fully reversible condition, especially when diagnosed and treated immediately. The main problem lies in the impairment of cerebral blood flow autoregulation which, in turn, leads to endothelial dysfunction and vasogenic brain oedema. MRI indicates cerebral oedema in the occipital, temporal, and parietal lobes. Brainstem involvement is very rare in the literature. Idiopathic thrombocytopenia-related PRES is also rare in the literature. In this article, a case of PRES with only pons involvement in MRI after hypertensive attack in a pregnant patient with idiopathic thrombocytopenia is presented. PRES may present only brainstem involvement, as seen in this present case. Whether or not mild hypertension and mild thrombocytopenia found in this case are associated with limited disease should be evaluated. Prolonged spreading depression may have a role in the pathophysiology of PRES.

A Case of Myoclonic Epilepsy Presenting with Status Epilepticus in an Elderly Male Patient.

Myoclonic epilepsy in the form of status epilepticus is an extremely rare reported presentation. Herein, we describe an 87-year old male patient presenting with abrupt-onset rhythmic myoclonic jerks that were evaluated as synchronous positive and negative myoclonus. Further etiological investigations revealed that the myoclonus was associated with ictogenesis, and appropriate antiepileptic treatment provided total cessation of the movements. To my knowledge, this is a unique case of myoclonic status epilepticus in an elderly patient, which may have been associated with a cerebrovascular disease. In the presentation of this case, we will review the related literature and discuss some considerations to explain the pathophysiology of epileptic myoclonic movements and the possible role of pontine lesions.

Pontine Tegmentum Lesions Accompanying Myelitis During an Enterovirus Outbreak: Differential Diagnosis and Outcome.

To investigate etiology and prognostic significance of pontine tegmentum lesions accompanying a cluster of acute flaccid myelitis. We retrospectively examined patients from 6 centers in Turkey who manifested encephalitis or myelitis associated with dorsal pontine lesions on magnetic resonance imaging (MRI) between July 2018 and February 2019. Twenty-two patients were evaluated. Ten of 22 (45%) presented with acute paralysis and 12 of 22 (55%) with brainstem symptoms only. Reverse transcription polymerase chain reaction for enterovirus was positive in 2 patients' respiratory tract. Other etiologic factors were detected in 10 cases. On follow-up, patients presenting with symptoms of myelitis developed motor sequalae although spinal cord lesions on MRI resolved in 5 of 9 (55%). Encephalitic symptoms, present in 17 cases, recovered in 13 (76%), and brain MRI showed complete or near-complete resolution in 11 of 14 (78%). Various etiologic agents can be detected in patients with pontine involvement, even in a series collected during an outbreak of EV-D68. Encephalitis has a fair outcome but clinical recovery is slow and motor sequalae are frequent in spinal involvement, irrespective of follow-up spinal MRI findings.

Identification of Enterovirus at Presentation Predicts Outcomes in Acute Flaccid Myelitis A Canadian Nationwide Study in Canada

Background: Acute flaccid myelitis (AFM) is characterized by rapid onset of limb weakness with spinal cord grey matter abnormalities on magnetic resonance imaging (MRI). It is unclear whether detection of enterovirus (EV) in respiratory or other specimens can help predict prognosis in children with AFM. Methods: In this nationwide longitudinal study, we evaluated the significance of peripheral detection of EV in predicting outcomes in a cohort of Canadian children presenting with AFM in 2014 and 2018. Clinical data, laboratory findings, treatment, and neuroimaging were collected (follow up period up to five years). We assessed neurologic function and motor outcomes using Kurtzke’s Expanded Disability Status Scale (EDSS) and a “weakest limb score” (WLS). Findings: 58 children with AFM (median 5⋅1 years [IQR 3⋅8-8⋅3]) were identified across five provinces. Twenty-two (39%) children had detectable EV in at least one specimen: EV-D68 in 14 (64%), EV-A71 in two (9%), coxsackievirus, and untyped EV in eight (36%). Children with EV detected were more likely to have had quadriparesis (55% vs. 12%, p=0⋅005), bulbar weakness (50% vs 6%, p=0⋅004), bowel/bladder dysfunction (59% vs 24%, p=0⋅033), cardiovascular instability (36% vs 6%, p=0⋅032), and were more likely to require intensive care unit admission (59% vs. 15%, p 0⋅005). On MRI, most children with EV positivity showed brainstem pontine lesions (59%), while other MRI parameters did not correlate with EV status. EDSS of EV+ and EV- groups was significantly different at baseline (median 8⋅5 [interquartile range, IQR 4-9⋅5] vs. 4⋅8 [IQR 3⋅4-7⋅1], p=0⋅012) and 12 months (median 3 [IQR 3-7] vs. 3 [IQR 2-3], p=0⋅036). Kaplan-Meier survival analysis of a subgroup of patients showed significantly poorer motor recovery among children with detected EV than those tested negative (p=0⋅032). Interpretation: Detection of EV in specimens from non-sterile sites at presentation correlated with more severe acute motor weakness, worse overall outcomes and poorer trajectory for motor recovery. Funding Statement: None. Declaration of Interests: EAY reports grants from Canadian Network of MS Clinics during the conduct of the study; grants from Biogen, grants from NMSS, grants from CMSC, grants from 18 MSSC/MS Foundation, grants from OIRM, grants from SCN, grants from SickKids Foundation, personal fees from ACI, personal fees from US FDA, grants from CBMH, grants from TEVA, grants from Guthy Jackson Foundation, personal fees from Juno, outside the submitted work. All other authors have no conflict of interest to disclose. Ethics Approval Statement: This study was approved by the research ethics board/committee of all above-listed participating institutions. Informed consents were obtained according to individual institutional requirements.