Motor Neuron Type Research Articles

Case 2: Multiple Cranial Nerve Palsies in a Neonate with a History of Perinatal Asphyxia

A singleton term male neonate is born of a nonconsanguineous marriage with no significant antenatal history and a birthweight of 2,600 g via cesarean section. He does not cry immediately after birth and is resuscitated with positive pressure ventilation for 2 minutes. The Apgar scores are 3 at 1 minute and 7 at 5 and 10 minutes. The extramurally delivered newborn is brought to the NICU for postresuscitation care. On initial examination, the neonate is encephalopathic with altered sensorium, hypotonia, and poor respiratory efforts. The heart rate is 110 beats/min with good volume pulses and a capillary refilling time of less than 3 seconds. Features of multiple right-sided lower motor neuron type of cranial nerve palsies (cranial nerves V, VII, IX, X) are seen on clinical examination. These include deviation of the angle of mouth to the left side, obliteration of nasolabial fold and failure to close the eyelid on the right side, abnormal gag reflex, and pooling of secretions. In view of poor breathing efforts, the newborn undergoes intubation and is started on conventional mechanical ventilation. Cord arterial blood gas reveals a pH of 7.25 and a base deficit of −5 mmol/L, which is normal. Routine supplementation with intravenous vitamin K is given. A provisional diagnosis of perinatal asphyxia with hypoxic-ischemic encephalopathy (HIE) with brainstem involvement is made. ### Day 1 to Day 10 The respiratory …

A Case Report of Recurrent unilateral Bell’s Palsy in young female

Most facial palsies comprise of lower motor neuron type or Bell’s palsy. The mean incidence of recurrence of Bell’s palsy is 6.5% and can recur at any age. Although it was first reported in the year 1871, most of its etiology, pathology, management and progression are still neither fully described nor reported. We reported a case of Bell’s palsy in a young Saudi female who was presented with a unilateral recurrent episode of Bell’s palsy. Patient came to the emergency department with facial asymmetry, severe neck pain, loss of sensation on the left side of face and headache, while she was also not responding to oral medications. She was admitted to the hospital for an intravenous treatment and for further evaluation. Her serologic investigation was unremarkable. Similar episode had occurred five years ago as well, which was completely resolved after treatment. Her brain MRI localized T2 and T2 weighted sequence showed hyperintense lesion at the superior anterior aspect of left orbit and could represent lipoma versus hemangioma. Her presenting complaint responded well on IV treatment and patient was discharged on 11th day. She was also referred for plastic and neurosurgery services for the treatment of underlying cause. Recurrent Bell’s palsy is infrequent with etiology not fully elucidated. However, our case emphasizes that the timely medical treatment with regular follow-up is necessary for better prognosis and identification and treatment of underlying cause.

Schwann cells selectively myelinate primary motor axons via neuregulin-ErbB signaling.

Spinal motor neurons project their axons out of the spinal cord via the motor exit point (MEP) and regulate their target muscle fibers for diverse behaviors. Several populations of glial cells including Schwann cells, MEP glia, and perineurial glia are tightly associated with spinal motor axons in nerve fascicles. Zebrafish have two types of spinal motor neurons, primary motor neurons (PMNs) and secondary motor neurons (SMNs). PMNs are implicated in the rapid response, whereas SMNs are implicated in normal and slow movements. However, the precise mechanisms mediating the distinct functions of PMNs and SMNs in zebrafish are unclear. In this study, we found that PMNs were myelinated by MEP glia and Schwann cells, whereas SMNs remained unmyelinated at the examined stages. Immunohistochemical analysis revealed that myelinated PMNs solely innervated fast muscle through a distributed neuromuscular junction (NMJ), whereas unmyelinated SMNs innervated both fast and slow muscle through distributed and myoseptal NMJs, respectively, indicating that myelinated PMNs could provide rapid responses for startle and escape movements, while unmyelinated SMNs regulated normal, slow movement. Further, we demonstrate that neuregulin 1 (Nrg1) type III-ErbB signaling provides a key instructive signal that determines the myelination of primary motor axons by MEP glia and Schwann cells. Perineurial glia ensheathed unmyelinated secondary motor axons and myelinated primary motor nerves. Ensheathment required interaction with both MEP glia and Schwann cells. Collectively, these data suggest that primary and secondary motor neurons contribute to the regulation of movement in zebrafish with distinct patterns of myelination.

Motoneuronal Spinal Circuits in Degenerative Motoneuron Disease.

The most evident phenotype of degenerative motoneuron disease is the loss of motor function which accompanies motoneuron death. In both amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), it is now clear that dysfunction is not restricted to motoneurons but is manifest in the spinal circuits in which motoneurons are embedded. As mounting evidence shows that motoneurons possess more elaborate and extensive connections within the spinal cord than previously realized, it is necessary to consider the role of this circuitry and its dysfunction in the disease process. In this review article, we ask if the selective vulnerability of the different motoneuron types and the relative disease resistance of distinct motoneuron groups can be understood in terms of their intraspinal connections.

Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm.

Motoneurons axotomized by peripheral nerve injuries experience profound changes in their synaptic inputs that are associated with a neuroinflammatory response that includes local microglia and astrocytes. This reaction is conserved across different types of motoneurons, injuries, and species, but also displays many unique features in each particular case. These reactions have been amply studied, but there is still a lack of knowledge on their functional significance and mechanisms. In this review article, we compiled data from many different fields to generate a comprehensive conceptual framework to best interpret past data and spawn new hypotheses and research. We propose that synaptic plasticity around axotomized motoneurons should be divided into two distinct processes. First, a rapid cell-autonomous, microglia-independent shedding of synapses from motoneuron cell bodies and proximal dendrites that is reversible after muscle reinnervation. Second, a slower mechanism that is microglia-dependent and permanently alters spinal cord circuitry by fully eliminating from the ventral horn the axon collaterals of peripherally injured and regenerating sensory Ia afferent proprioceptors. This removes this input from cell bodies and throughout the dendritic tree of axotomized motoneurons as well as from many other spinal neurons, thus reconfiguring ventral horn motor circuitries to function after regeneration without direct sensory feedback from muscle. This process is modulated by injury severity, suggesting a correlation with poor regeneration specificity due to sensory and motor axons targeting errors in the periphery that likely render Ia afferent connectivity in the ventral horn nonadaptive. In contrast, reversible synaptic changes on the cell bodies occur only while motoneurons are regenerating. This cell-autonomous process displays unique features according to motoneuron type and modulation by local microglia and astrocytes and generally results in a transient reduction of fast synaptic activity that is probably replaced by embryonic-like slow GABA depolarizations, proposed to relate to regenerative mechanisms.

Migrainous facial palsy (MFP): the introduction of a new concept of neurovascular conflict and its preliminary clinical evidence.

Facial palsy and migraine have frequently been reported to occur in conjunction. We report a case series and propound a theory to explain the same. To postulate an anatomico-pathophysiological association in the causative factor of lower motor neuron type of facial palsy in cases with migraine without aura. Preliminary experiences and observations in 12 cases suffering from facial palsy following an attack of migraine without aura, mainly in the occipital and posterior auricular region, are elaborated. Facial palsy occurred on the ipsilateral side as the headaches in a majority of the cases (83.33%) and in rare cases of bilateral headaches (16.67%), it lateralised to the side the headaches were more severe. In most of these cases (75%), a complete clinical recovery was noted within 6months. We concluded that neurogenic inflammation of the facial nerve trunk caused by its proximity to the dilated posterior auricular/stylomastoid/occipital and superficial temporal arteries during a migraine attack leads to a temporary lower motor neuron type of paresis of the muscles supplied by the facial nerve. This pathophysiological understanding of the disease mechanism could open new avenues as to the treatment of this condition. This proposition indicates in clearer light than before, a possible mechanism to explain the higher incidence and risk of facial palsy in migraineurs.

A very young patient with Tubercular Meningitis and its complications

A case report on a successful management of an eight months old boy with Tubercular Meningitis with Multiple Tuberculoma in Brain with Obstructive Hydrocephalus with Left sided Lower motor neuron type Facial Palsy with Right Sided Hemiparesis. Tuberculous meningitis (TBM) is Mycobacterium tuberculosis infection of the Brain Meninges.1,2 In TBM inflammation occur mainly in the base of the brain and when the inflammation affect the brain stem subarachnoid area, cranial nerve roots then symptoms may occur like space-occupying lesions.3,4 TBM is more common in children than in adults, especially children aged 0-5 years.5 In children central nervous system tuberculosis usually presents as tubercular meningitis, post-tubercular meningitis hydrocephalus, and rarely a space-occupying lesions known as tuberculomas.6 TBM accounts for 2–5% of all active cases of Mycobacterium tuberculosis.7 Pulmonary infection coexists in 25–83% of TBM.8-10 Predominately primary CNS infection is found in children and leptomeningeal infection presents as meningitis, cranial nerve (CN) palsies (most commonly CN 2, 3, 4, and 7), and communicating hydrocephalus.11
 Northern International Medical College Journal Vol.10 (2) Jan 2019: 400-401

Outcome of Bell’s Palsy- An Institutional Study

Background and purpose: Bell’s palsy represents sudden onset of lower motor neuron type of facial palsy in the absence of other cranial nerve involvement. Pathophysiologically, it has been described mostly due to viral infection, and early use of antiviral therapy, steroids and physiotherapy has shown to limit the disease and helps in early recovery from palsy. With the objective to evaluate over all clinical outcome of the patients presented with Bell’s palsy with our treatment strategies this study was performed. 
 Material and method: This is a prospective analytical study with non probability consecutive sampling technique over the duration of 6 months. Continuous variable like age is presented using mean and standard deviation. Categorical data are presented as percentage and analysis of outcome of the treatment is done using Fischer’s exact test. Statistical analysis was done using SPSS -20.
 Result: Total number of patients enrolled in the study was 19, where mean age was 33.47 (SD 15.71) years. Bell’s palsy was more commonly seen in female patients (58%). House Brackmann grading of facial nerve palsy at the time of presentation was four. There was significant association of early treatment with complete recovery in this study.
 Conclusion: Early treatment of bells palsy with acyclovir, steroids, and physiotherapy has shown promising result in most of the studies; and this holds true in this study as well, where delaying the treatment was significantly associated with poorer recovery.

Neurocysticercosis in a 14-year-old Nigerian: A case report and review of the literature

Neurocysticercosis (NCC), an infection of the brain by the larval form of Taenia solium tapeworm, has been described as the most common cause of acquired adult seizure and epilepsy in regions of the world where the worm infestation is endemic. It is acquired following ingestion of raw or partially cooked pork-containing cysts of T. solium. We report the case of a 14-year-old male patient, who presented with recurrent tonic–clonic partial seizures of 3 months duration, seizures, and progressive weakness of the left limb, while being fully conscious. He had a left facioparesis of the upper motor neuron type with plastic left hemiparesis. An impression of a right frontal cortical lesion was made. The laboratory investigations as well as the chest radiograph were reported as being essentially unremarkable. The magnetic resonance image of the brain revealed a circumscribed right parietal lesion which was circumscribed. A provisional diagnosis of intracranial tumor was then made. Surgery involved an en bloc resection of a cystic right parietal mass. The gelatinous fluid contained within was submitted for cytological examination. The latter revealed the presence of a cysticercus comprising the scolex, spiral canal, and the bladder wall. A diagnosis of NCC was made, and the patient was thereafter commenced on antihelminthics. The patient made an appreciable recovery thereafter. This report is to emphasize the continued existence of this disease, the need to improve diagnostic suspicion, and skill. This report further supports the proposal to declare NCC an international reportable disease.

Target-wide Induction and Synapse Type-Specific Robustness of Presynaptic Homeostasis.

Presynaptic homeostatic plasticity (PHP) is an evolutionarily conserved form of adaptive neuromodulation and is observed at both central and peripheral synapses. In this work, we make several fundamental advances by interrogating the synapse specificity of PHP. We define how PHP remains robust to acute versus long-term neurotransmitter receptor perturbation. We describe a general PHP property that includes global induction and synapse-specific expression mechanisms. Finally, we detail a novel synapse-specific PHP expression mechanism that enables the conversion from short- to long-term PHP expression. If our data can be extended to other systems, including the mammalian central nervous system, they suggest that PHP can be broadly induced and expressed to sustain the function of complex neural circuitry.

Guillain-Barr\xe9 syndrome with associated unilateral ptosis without ophthalmoplegia \u2013 a rare presentation: a case report and review of the literature

BackgroundGuillain-Barré syndrome is an acute inflammatory polyradiculoneuropathy. Nearly half of patients with Guillain-Barré syndrome have cranial nerve involvement. However, isolated bilateral ptosis without ophthalmoplegia is a rare manifestation, and isolated unilateral ptosis without ophthalmoplegia in Guillain-Barré syndrome has not previously been reported in the literature. Furthermore, only few cases of Guillain-Barré syndrome with cranial nerve enhancement visualized by gadolinium-enhanced magnetic resonance imaging have previously been reported. We describe the first reported case of unilateral ptosis without ophthalmoplegia in Guillain-Barré syndrome and associated multiple cranial nerve enhancement seen by gadolinium-enhanced magnetic resonance imaging.Case presentationOur patient was a 55-year-old Sinhalese man who was admitted to a tertiary care hospital in Sri Lanka with acute-onset progressive weakness in the lower limbs followed by the upper limbs. He had bilateral symmetrical flaccid quadriparesis with absent reflexes and flexor plantar response. Left-sided isolated partial ptosis without associated ophthalmoplegia was noted with normal pupils. The patient’s neurological examination was otherwise normal. A nerve conduction study showed a severe demyelinating type of polyneuropathy. No decremental response to repetitive nerve stimulation was observed, and the result of a single-muscle-fiber electromyogram was negative. A diagnosis of Guillain-Barré syndrome was made, and the patient was treated with intravenous immunoglobulin. His condition gradually deteriorated over the next few days, and he became quadriplegic despite the completion of immunoglobulin therapy. Later he developed multiple cranial nerve palsies, including bi-lateral lower motor neuron type facial nerve palsy, and he required mechanical ventilation. By this time, he had complete left-sided ptosis with a normal right eye. He never developed ophthalmoplegia or ataxia. Magnetic resonance imaging of the brain showed contrast enhancement in the intracranial part of multiple cranial nerve roots and basal leptomeninges. He gradually improved with plasmaparesis, and ptosis was the first to improve.ConclusionsEven though Guillain-Barré syndrome was recognized a century ago, there are still many unanswered questions about it and its florid presentation. Large-scale studies are needed for better understanding of its pathophysiology and prototypes and to find answers for still-unanswered questions. The clinician must have a high index of suspicion and be familiar with mimics and prototypes to diagnose Guillain-Barré syndrome accurately without delay.

P.008 Triphasic waves in powassan encephalitis: a case report

Background: Powassan virus is a tick borne virus which can lead to encephalitis. Methods: 63 year old woman with history of migraine presented with 2 days of fever, headache, language difficulty and right sided facial droop. Her examination revealed right upper motor neuron type facial weakness and expressive aphasia. She rapidly deteriorated within 24 hours becoming non verbal and ultimately comatose. Results: MRI brain revealed T2 hyperintensities in bilateral caudate and putamen. Subsequent MRI brain showed progression of the caudate and basal ganglia changes and new T2 hyperintensities in bilateral thalami and midbrain with no abnormal enhancement. CSF revealed lymphocytic pleocytosis with normal protein and glucose. Viral Encephalitis was suspected and she was continued on Acyclovir until Varicella zoster and Herpes simplex virus serology in CSF returned negative. Prolonged video EEG showed near continuous generalized triphasic pattern without any evolution or seizure pattern. There was no improvement in clinical status or EEG with antiepileptic treatment. Paraneoplastic panel , serum HIV, Lyme and 14-3-3 protein were negative. Extensive viral serologies were sent and ultimately Powassan serology came back positive. Conclusions: This case highlights powassan virus as a cause of encephalitis and occurrence of triphasic waves in non metabolic causes of encephalopathy such as infectious encephalitis.

Isolated facial nerve palsy: Rare manifestation of dengue haemorrhagic fever - A case report

Dengue is a common arboviral infection and is one of the tropical diseases which occur in Sri Lanka. Neurological manifestations due to dengue are very rare but can be caused by serotypes 2 and 3. Here we report of an isolated facial nerve palsy occurring as a manifestation of dengue haemorrhagic fever (DHF) in a young boy who presented with fever and constitutional symptoms. Haematological parameters were suggestive of dengue with dengue IgM being positive. Subsequently, he developed right side lower motor neuron type of facial nerve palsy. He was treated with a high dose of steroids and facial nerve stimulation therapy. He clinically recovered without residual weakness.

GAL4 Drivers Specific for Type Ib and Type Is Motor Neurons in Drosophila.

The Drosophila melanogaster larval neuromuscular system is extensively used by researchers to study neuronal cell biology, and Drosophila glutamatergic motor neurons have become a major model system. There are two main Types of glutamatergic motor neurons, Ib and Is, with different structural and physiological properties at synaptic level at the neuromuscular junction. To generate genetic tools to identify and manipulate motor neurons of each Type, we screened for GAL4 driver lines for this purpose. Here we describe GAL4 drivers specific for examples of neurons within each Type, Ib or Is. These drivers showed high expression levels and were expressed in only few motor neurons, making them amenable tools for specific studies of both axonal and synapse biology in identified Type I motor neurons.

Clinical Improvement with Non-Surgical Management of Tuberculous Spondylitis

Background: Tuberculosis is the second most common fatal infectious disease after Acquired Immunodeficiency Syndrome (AIDS) in the world. The spine is involved in 50% of osteoarticular tuberculosis cases. Tuberculous Spondylitis (TS) is the most dangerous form of osteoarticular tuberculosis, because of its ability to destroy the vertebral body with subsequent permanent kyphosis and neurological deficits such as paraplegia. The treatment goals of TS are to eradicate the infection and provide stability for the affected spine. There is little information in the literature about systemic non-surgical treatment under the condition of spinal cord compression in TS. We report two cases of TS which was improved with non-surgical treatment. We believe that the clinico-radiological signs of spinal cord compression in these cases are not an emergency indication for surgery. Clinical Presentation and Intervention: Two women aged 34 and 26 years were hospitalized because of the upper motor neuron type weakness in both legs worsened gradually, descending numbness, without urinary or defecation problems. Magnetic resonance imaging depicted lesions on vertebral bodies supporting the diagnosis of TS. Both patients were received oral antituberculous therapy and their muscle force improved despite the kyphotic deformity in the first patient. Conclusion: Neuro-radiological evidence of spinal cord compression is not an emergency indication of surgery in the management of TS and clinical improvement can be obtained by non-surgical treatment.

Clinical study on etiology and management of lower motor neuron type palsy of facial nerve at a tertiary care hospital, Ballari, Karnataka

Clinical study on etiology and management of lower motor neuron type palsy of facial nerve at a tertiary care hospital, Ballari, Karnataka

Melkersson Rosenthal Syndrome: a case report and review of the literature

Melkersson Rosenthal Syndrome (MRS) is a rare neurological disorder characterized by swelling of the face, particularly one or both lips (granulomatous cheilitis), facial muscle weakness (palsy) and a fissured tongue. We present a patient with Melkersson Rosenthal Syndrome, highlighting the clinical triad of symptoms and management. A74-year-old Nigerian male presented to the Oral Medicine Clinic of the University of Benin Teaching Hospital for evaluation of right-sided facial numbness, inability to close the right eye, left facial deviation suggestive of a lower motor neuron type facial palsy of 4 days, and painless swelling of the upper and lower lips for seven days. On examination, he was found to have swelling of the upper and lower lips, multiple fissures on the tongue, right facial paresthesia, and an isolated right-sided facial nerve paralysis. He was empirically managed with 50mg prednisone daily for seven days, which was tapered over two weeks and neurobion 1 tablet daily for a month. This resulted in remission of lip swelling, however fissured tongue remained. Two months later, facial deviation had become less apparent. Patient is being followed up in the outpatient clinic. Melkersson Rosenthal Syndrome is a rare disorder with features of facial swelling, facial nerve palsy and fissured tongue. Some affected individuals may have all three of these features and others may have only one or two. The diagnosis of MRS can be made clinically when there is a complete triad of symptoms as reported in our patient.Keywords: Melkersson Rosenthal Syndrome, clinical symptoms, management

Distinct descending motor cortex pathways and their roles in movement.

Activity in the motor cortex predicts movements, seconds before they are initiated. This preparatory activity has been observed across cortical layers, including in descending pyramidal tract neurons in layer 5. A key question is how preparatory activity is maintained without causing movement, and is ultimately converted to a motor command to trigger appropriate movements. Here, using single-cell transcriptional profiling and axonal reconstructions, we identify two types of pyramidal tract neuron. Both types project to several targets in the basal ganglia and brainstem. One type projects to thalamic regions that connect back to motor cortex; populations of these neurons produced early preparatory activity that persisted until the movement was initiated. The second type projects to motor centres in the medulla and mainlyproduced late preparatory activity and motor commands. These results indicate that two types of motor cortex output neurons have specialized roles in motor control.

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 302:505-511, 2019. © 2018 Wiley Periodicals, Inc.

Acute Motor Axonal Polyneuropathy Following Mumps Infection in a 9-Year-Old Girl

A 9-year-old girl presented with lower motor neuron type of paralysis involving limbs, trunk and multiple cranial nerves (7, 9 and 10) with preceding history of mumps 1 week before the onset of weakness. There were no features to suggest either a meningitis or encephalitis in the child. Cerebrospinal fluid showed hypoglycorrhachia and mild protein elevation; magnetic resonance imaging of the brain was normal. Nerve conduction study showed motor axonal neuropathy. Serology for mumps IgM was positive, consistent with a diagnosis of post-mumps acute motor axonal polyneuropathy. The girl made a complete recovery within 3 weeks.