Motor Neuron Type Research Articles

Linear Scleroderma of Scalp “en coup de sabre” in a Child Presenting with Rapidly Deteriorating Acute Encephalopathy

Background: Linear scleroderma (LS) is a variant of localized scleroderma, which is termed as “en coup de sabre” (ECDS) when it involves the head and/or face. Although mainly a dermatological condition, extracutaneous manifestations have been infrequently reported. Clinical Description: A 13-year-old boy presented with fever, altered sensorium with seizures, right hemiparesis, and right-sided upper motor neuron type of facial palsy. He was noticed to have a depression in the left frontoparietal area of the scalp with skin changes. Management and Outcome: The child was initially managed along the lines of acute encephalitis supported with mechanical ventilation. Brain imaging revealed tiny calcification in the left temporal and parietal lobes with altered signal intensities ipsilateral to the scalp lesion. Suspecting an association with the overlying scalp skin lesion, biopsy of the skin lesion was done which confirmed LS. The erythrocyte sedimentation rate was elevated and the antinuclear antibody was positive. The child was started on pulse methylprednisolone following which encephalopathy improved facilitating extubation. Later, he was started on subcutaneous methotrexate and he improved on follow-up. Conclusion: This case creates awareness regarding the association between neurological manifestations and LS EDCS, which responds favorably to immunosuppressives and methotrexate.

Unmasking Ataxic Guillain–Barre Syndrome: A Rare Presentation

Abstract A 68-year-old right-handed male with a history of hypertension presented with unsteadiness while walking for 5 days preceded by a vague pain in the left shoulder and both thighs and paresthesias in all extremities. It rapidly progressed to severe gait ataxia, bilateral facial palsy, and speech difficulties. On examination, he had bilateral lower motor neuron type of facial palsy, a wide-based stance, gait ataxia, left-sided hypotonia, cerebellar signs, and generalized areflexia. He had left-sided hypotonia and normal power of all four limbs. Sensory system examination was normal, and Rhomberg’s sign was negative. He had no ophthalmoplegia. While initial considerations pointed toward a cerebrovascular accident, normal magnetic resonance imaging results prompted us to do a lumbar puncture and cerebrospinal fluid analysis, which revealed albuminocytological dissociation indicative of Guillain–Barré Syndrome (GBS). Nerve conduction studies then confirmed our diagnosis. Given these results and a preceding respiratory infection, the patient was diagnosed with a rare ataxic variant of GBS. The patient was treated with plasmapheresis following which he showed dramatic clinical improvement. He was subsequently able to walk without support and perform the majority of his day-to-day activities on his own. He was discharged in a hemodynamically stable condition. This case report, thus, highlights a rare ataxic variant of GBS presenting with acute onset ataxia, areflexia, and facial diplegia. Thus, understanding the GBS and its variants is crucial to managing rare presentations swiftly and avoiding severe complications. It has tremendous scope for further research to understand the pathophysiological dynamics completely and find more targeted therapeutic approaches. We, thus, present a rare case of an ataxic variant of GBS with acute onset ataxia, areflexia, and facial diplegia.

When Guillain–Barré Syndrome Defies Expectations: A Case of Atypical Features

Abstract Guillain–Barré syndrome (GBS) is one of the most common causes of acute flaccid paralysis. In typical GBS, there are no central nervous system (CNS) features. GBS with prominent CNS involvement can be seen in uncommon variants of GBS (such as Miller Fisher Syndrome and Bickerstaff brainstem encephalitis [BBE]) or rarely, when it coexists with other conditions such as acute disseminated encephalomyelitis (ADEM). We report a case of a 35-year-old male who presented with fever followed by ascending lower motor neuron type paraparesis suggestive of GBS which progressed rapidly to involve the respiratory muscles necessitating invasive mechanical ventilation. The patient had many atypical features, namely, persistent fever, early bladder and bowel involvement, facial twitching, ophthalmoplegia with ptosis, and a comatose state. Based on these clinical features and the investigations done, a diagnosis of GBS with BBE with a possibility of ADEM was made. The patient was managed intensively, but there was no improvement in the neurological manifestations and the patient succumbed to the illness due to ventilator-associated complications.

Onion skin is not a universal firing pattern for spinal motoneurons: simulation study.

Muscle force is modulated by sequential recruitment and firing rates of motor units (MUs). However, discrepancies exist in the literature regarding the relationship between MU firing rates and their recruitment, presenting two contrasting firing-recruitment schemes. The first firing scheme, known as "onion skin," exhibits low-threshold MUs firing faster than high-threshold MUs, forming separate layers akin to an onion. This contradicts the other firing scheme, known as "reverse onion skin" or "afterhyperpolarization (AHP)," with low-threshold MUs firing slower than high-threshold MUs. To study this apparent dichotomy, we used a high-fidelity computational model that prioritizes physiological fidelity and heterogeneity, allowing versatility in the recruitment of different motoneuron types. Our simulations indicate that these two schemes are not mutually exclusive but rather coexist. The likelihood of observing each scheme depends on factors such as the motoneuron pool activation level, synaptic input activation rates, and MU type. The onion skin scheme does not universally govern the encoding rates of MUs but tends to emerge in unsaturated motoneurons (cells firing < their fusion frequency that generates peak force), whereas the AHP scheme prevails in saturated MUs (cells firing at their fusion frequency), which is highly probable for slow (S)-type MUs. When unsaturated, fast fatigable (FF)-type MUs always show the onion skin scheme, whereas S-type MUs do not show either one. Fast fatigue-resistant (FR)-type MUs are generally similar but show weaker onion skin behaviors than FF-type MUs. Our results offer an explanation for the longstanding dichotomy regarding MU firing patterns, shedding light on the factors influencing the firing-recruitment schemes.NEW & NOTEWORTHY The literature reports two contrasting schemes, namely the onion skin and the afterhyperpolarization (AHP) regarding the relationship between motor units (MUs) firing rates and recruitment order. Previous studies have examined these schemes phenomenologically, imposing one scheme on the firing-recruitment relationship. Here, we used a high-fidelity computational model that prioritizes biological fidelity and heterogeneity to investigate motoneuron firing schemes without bias toward either scheme. Our objective findings offer an explanation for the longstanding dichotomy on MU firing patterns.

LIU Zhishun's clinical experience of electroacupuncture for pediatric neurogenic bladder of lower motor neuron type in children

Professor LIU Zhishun's clinical experience of electroacupuncture (EA) for pediatric neurogenic bladder of lower motor neuron type in children is summarized. Considering the unique physiological and pathological characteristics of children, with the strategy of combining "disease-symptom-location" in the selection of acupoints, professor LIU Zhishun proposes that the main disease location is the bladder and kidney, with the involvement of the conception vessel, governor vessel, kidney meridian of foot-shaoyin and the bladder meridian of foot-taiyang. The primary acupoint prescription-1 (bilateral Zhongliao [BL 33], Ciliao [BL 32] and Huiyang [BL 35]) and primary acupoint prescription-2 (Guanyuan [CV 4], Zhongji [CV 3] and bilateral Sanyinjiao [SP 6]) are selected to promote the yang of the governor vessel, stimulate the yin of the conception vessel, and invigorate the bladder's qi transformation. Before acupuncture, the four-step method is applied to precisely locate Ciliao (BL 32) and Zhongliao (BL 33). During acupuncture, the importance of achieving deqi is emphasized, with deep insertion in the sacral area to reach the disease location. Based on the tolerance characteristics of children, low-frequency EA and gentle moxibustion treatment are applied.

Moyamoya Syndrome in a Child with Beta-Thalassemia Trait: A Case Report with Review of Literature

Background: The association of moyamoya angiopathy with hematological conditions such as sickle cell anemia and beta-thalassemia major or intermedia is well-known, but moyamoya syndrome (MMS) associated with thalassemia trait is hardly reported. We report such a rare association. Clinical Description: A 7-year-old boy presented with right-sided monoparesis with right-sided focal seizures, along with right-sided upper motor neuron type facial nerve palsy. He had a history of recurrent transient episodes of limb weakness, which were unevaluated. Examination revealed pallor and mild splenomegaly. Management and Outcome: Routine investigations revealed microcytic hypochromic anemia with normal serum iron levels. High-performance liquid chromatography was suggestive of beta-thalassemia trait. Contrast-enhanced computerized tomography of the head showed infarction in the territory of the left anterior cerebral artery (ACA) and middle cerebral artery (MCA). Magnetic resonance angiography revealed significantly attenuated bilateral internal carotid arteries in the supraclinoid region with attenuated bilateral ACA and bilateral MCA along with collateral formation suggestive of moyamoya angiopathy. The final diagnosis of MMS secondary to beta-thalassemia trait was made. The child improved with aspirin and supportive management. Conclusion: MMS can be rarely associated with the beta-thalassemia trait. Such an underlying, unsuspected heterozygous beta-thalassemia (trait) may be diagnosed only after the identification of moyamoya disease following a stroke.

Case Study Insights: Passive Range of Motion and Extended Stretching in Improving Functional Mobility for Individuals with Spastic Cerebral Palsy

Cerebral Palsy (CP) is a non-progressive neuromuscular disorder of cerebral origin. It includes a number of clinical disorders, mostly arising in childhood. The essential features vary the degree of upper motor neuron type of limb paralysis (spasticity 70-80%), together with difficulty in coordination (ataxia) and purposeless movements (athetosis). A single case study 3 years old male of spastic CP &amp; with a score of 2 on a modified Ashworth scale, Chief complaints of difficulty in neck control &amp; delayed milestones. Passive ROM and prolonged stretching for the lower limb have been given to improve ROM, spasticity and mobility. decrease in spasticity and improvement in range of motion. There was a significant decrease in spasticity and improvement in the range of motion by using the digital goniometer and modified Ashworth scale in children with spastic cerebral palsy. Keywords: Cerebral palsy, Stretching, Spasticity

Spontaneous thrombosis of unruptured berry aneurysm presenting as facial palsy

Spontaneous thrombosis of saccular unruptured intracranial aneurysm (UIAs) is a known occurrence in giant aneurysms. However, spontaneous complete or partial thrombosis of non-giant aneurysms is a rare event in the natural history of UIAs that can be discovered incidentally on advanced neuroradiologic studies. They occasionally present with ischemic stroke, which is rare entity. Parent artery occlusion due to local extension of the luminal thrombus, aneurysms ejecting emboli to distal arteries, or increased mass effect have been described as possible pathogenic mechanisms. Guidelines for the management of these patients were limited. We present a documented case of this unusual entity a case of non-giant intracranial aneurysm with spontaneous thrombosis presenting as Upper motor neuron type of facial palsy due to acute ischemic stroke.

Selective vulnerability of motor neuron types and functional groups to degeneration in amyotrophic lateral sclerosis: review of the neurobiological mechanisms and functional correlates.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative condition characterised by a progressive loss of motor neurons controlling voluntary muscle activity. The disease manifests through a variety of motor dysfunctions related to the extent of damage and loss of neurons at different anatomical locations. Despite extensive research, it remains unclear why some motor neurons are especially susceptible to the disease, while others are affected less or even spared. In this article, we review the neurobiological mechanisms, neurochemical profiles, and morpho-functional characteristics of various motor neuron groups and types of motor units implicated in their differential exposure to degeneration. We discuss specific cell-autonomous (intrinsic) and extrinsic factors influencing the vulnerability gradient of motor units and motor neuron types to ALS, with their impact on disease manifestation, course, and prognosis, as revealed in preclinical and clinical studies. We consider the outstanding challenges and emerging opportunities for interpreting the phenotypic and mechanistic variability of the disease to identify targets for clinical interventions.

Single-cell RNAseq analysis of spinal locomotor circuitry in larval zebrafish

Identification of the neuronal types that form the specialized circuits controlling distinct behaviors has benefited greatly from the simplicity offered by zebrafish. Electrophysiological studies have shown that in addition to connectivity, understanding of circuitry requires identification of functional specializations among individual circuit components, such as those that regulate levels of transmitter release and neuronal excitability. In this study, we use single-cell RNA sequencing (scRNAseq) to identify the molecular bases for functional distinctions between motoneuron types that are causal to their differential roles in swimming. The primary motoneuron, in particular, expresses high levels of a unique combination of voltage-dependent ion channel types and synaptic proteins termed functional ‘cassettes.’ The ion channel types are specialized for promoting high-frequency firing of action potentials and augmented transmitter release at the neuromuscular junction, both contributing to greater power generation. Our transcriptional profiling of spinal neurons further assigns expression of this cassette to specific interneuron types also involved in the central circuitry controlling high-speed swimming and escape behaviors. Our analysis highlights the utility of scRNAseq in functional characterization of neuronal circuitry, in addition to providing a gene expression resource for studying cell type diversity.

Management of Ardita (Bell’s palsy) through Ayurvedic Approach

Bell’s palsy is the most common form of unilateral isolated lower motor neuron type of facial palsy. This is an idiopathic condition with abrupt onset leading to weakness of one-half of the face. The present case report is on the effectiveness of Nasya Karma and Shirodhara procedures in Bell’s palsy. A 35-year-old female patient visited the OPD with complaints of deviation of the mouth, improper closure of eyes, and dribbling of saliva for four days. She was diagnosed with Bell’s palsy. Bell’s palsy can be correlated with Ardita based on clinical features. The patient was hospitalized and managed with Sthanik Snehana (localized oleation /massage therapy), Sthanik Swedana (localized steam), Nasya Karma (medicine administered through nasal route), and Shirodhara (medicated decoction/oil pouring over the forehead) along with oral Ayurvedic formulations. She got noteworthy relief in all features in two weeks. The collected data emphasize the potential of Ayurvedic interventions in Bell’s palsy (Ardita).

Effects of low-intensity exercise on contractile property of skeletal muscle and the number of motor neurons in diabetic rats.

The mode of diabetes-induced muscle and motor neuron damage depends on the type of muscle and motor neuron. One of the purposes of exercise therapy for diabetes is to improve blood glucose levels; however, information on the effects of low-intensity exercise on muscle and motor neuron disorders remain unknown. Therefore, this study aimed to examine the effects of low-intensity exercise on diabetes-induced muscle and motor neuron damage in a rat model of type 1 diabetes mellitus. We subjected adult male Wistar rats treated with streptozotocin to develop type 1 diabetes and age-matched rats to low-intensity treadmill exercise for 12weeks. We recorded electrically evoked maximum twitch tension in leg muscles, and examined the number of motor neurons and cell body sizes. Low-intensity exercise ameliorated the prolonged half-relaxation time and the decreased numbers of the retrograde-labeled motor neurons observed in the soleus muscle of type 1 diabetic rats. However, no effect was observed in the diabetic group, as atrophy was not improved and the twitch force in the medial gastrocnemius muscle was decreased in the diabetic group. In addition, there was no improvement in the blood glucose levels after exercise. These data indicate that low-intensity exercise may relieve the onset of muscle and motor neuron damage in the soleus muscle of type 1 diabetic rats.

A case of Bell’s palsy successfully treated with homoeopathy

Bell’s palsy is an acute unilateral facial palsy of the lower motor neuron type predominantly affecting middle aged men. Although exact aetiology is unknown, but probable causes include entrapment of the nerve at the mental foramen and vasospasm due to external factors. Surgical management along with medical management provides an assuring relief for the Bell’s palsy sufferers, may produce adverse effects such as facial nerve palsy or post-surgical synkinesis. Homoeopathic medicines, when selected based on signs and symptoms, act on the vital force dynamically and gently restore the nerve functioning to normal. Here, we present a case of left-sided Bell’s palsy recovered with homoeopathic medicines prescribed on the basis of causation and side affinity. The recovery was assessed by the House Brackmann scale and the quality of life was assessed using the modified Naranjo criteria.

A rare case of Guillain-Barrè syndrome with unilateral facial palsy and asymmetrical ascending weakness: a case report.

A 39-year-old male presented with pain and weakness in the right lower limb with right sided facial weakness. The cranial nerve examination revealed lower motor neuron type right facial palsy (Bell 's palsy). On rest neurological examination, he had decreased power in the right lower limb with an absent knee and ankle reflex on presentation. Later, the weakness was symmetrical in both lower limbs. Cerebrospinal fluid analysis showed albuminocytologic dissociation with no cells and an elevated protein of 203.2mg/dl. The nerve conduction study was abnormal in bilateral lower limbs suggesting severe demyelinating motor neuropathy. Intravenous Immunoglobulin was started with the dose of 25gm (0.4mg/kg) once daily for 5 days, that is, five doses. The patient started showing signs of recovery with the initial dose of immunoglobulin. The course of the disease usually recovers spontaneously and completely; however, plasma exchange and immunomodulatory therapy have shown improvement in patient with rapidly deteriorating symptoms.

Eight-and-a-half syndrome – A rare presentation of pontine infarction

Eight-and-a-half syndrome is clinically characterized by conjugate gaze palsy and internuclear ophthalmoplegia along with lower motor neuron type facial nerve palsy. Usually, it occurs because of infarction or demyelinating disease at paramedian tegmentum of lower pons. It emphasizes the importance of checking ocular movements. A 55-year-old male patient presented with sudden onset of double vision, headache, and vomiting and found to have horizontal gaze palsy, internuclear ophthalmoplegia, and facial palsy of the left side. High blood pressure was noted. Clinically, eight and a half syndrome was identified. MRI brain showed infarct at pons. The patient was stabilized systemically. A detailed clinical neuro-ophthalmic examination, along with a clear understanding of the neuro-anatomical pathways, gives clinicians a good diagnostic opportunity to localize precisely lesions in the brainstem. The disease should be evaluated for etiology.

Facial nerve palsy: An atypical presentation of dengue fever

Dengue fever is a grave public health concern in tropical countries. The disease spectrum of dengue fever is multi-systemic, although neurologic complications of dengue fever is relatively uncommon. The pathogenesis of neurologic manifestations in dengue fever is not well understood and may be due to the neurotrophic effect of the virus, or related to the systemic effects of dengue infection, and immune mediated. Here in, we discuss the occurrence of isolated 7th cranial nerve lower motor neuron type palsy in a 23-year-old lady suffering from dengue fever. To date, there are very few case reports citing the involvement of facial nerve in dengue fever.

Preservation of KCC2 expression in axotomized abducens motoneurons and its enhancement by VEGF.

The potassium chloride cotransporter 2 (KCC2) is the main Cl- extruder in neurons. Any alteration in KCC2 levels leads to changes in Cl- homeostasis and, consequently, in the polarity and amplitude of inhibitory synaptic potentials mediated by GABA or glycine. Axotomy downregulates KCC2 in many different motoneurons and it is suspected that interruption of muscle-derived factors maintaining motoneuron KCC2 expression is in part responsible. In here, we demonstrate that KCC2 is expressed in all oculomotor nuclei of cat and rat, but while trochlear and oculomotor motoneurons downregulate KCC2 after axotomy, expression is unaltered in abducens motoneurons. Exogenous application of vascular endothelial growth factor (VEGF), a neurotrophic factor expressed in muscle, upregulated KCC2 in axotomized abducens motoneurons above control levels. In parallel, a physiological study using cats chronically implanted with electrodes for recording abducens motoneurons in awake animals, demonstrated that inhibitory inputs related to off-fixations and off-directed saccades in VEGF-treated axotomized abducens motoneurons were significantly higher than in control, but eye-related excitatory signals in the on direction were unchanged. This is the first report of lack of KCC2 regulation in a motoneuron type after injury, proposing a role for VEGF in KCC2 regulation and demonstrating the link between KCC2 and synaptic inhibition in awake, behaving animals.

Isolated Insular Stroke: An Interesting Report of Two Cases.

Isolated Insular Stroke: An Interesting Report of Two Cases.

Abstract Number ‐ 226: Pontine Stroke Presenting as 1.5 Syndrome Evolving to 9 Syndrome over 72 Hours.

Introduction A 75 year old woman with a past medical history of hypertension developed sudden‐onset vertigo, nausea and vomiting. She did not immediately seek medical care, thinking she was suffering from food poisoning. The following day her symptoms improved however she developed new right sided weakness and gait imbalance, prompting her presentation to the ED. Her neurologic exam noted complete loss of adduction of the right eye and loss of horizontal extraocular movements of the left eye. She also displayed right upper extremity paresis, right upper extremity dysmetria and mild dysarthria. MRI of the brain disclosed acute pontine infarcts in the ventral and dorsal left paramedian regions. Over the next three days, her horizontal gaze palsy improved with some return of adduction of the right eye and horizontal movements of the left eye. However right sided paresis worsened, and in addition, progressed to include complete left facial palsy (lower motor neuron lesion). She was able to be discharged to rehab, placed on Aspirin 81 mg daily and Ezetimibe (due to elevated liver function enzymes) and 30 day Cardiac Event Monitor follow up. Methods Case report and review of literature. Results Due to the combination of multiple cranial nuclei and white matter tracts in the brainstem, ischemia can lead to several clinical manifestations. There are various presenting clinical syndromes, named numerically by structures involved and/or the clinical deficit. One‐and‐a‐half (1.5) syndrome, first reported by Fischer in 1967, is an uncommon entity caused by a lesion (most commonly infarction) in the pontine tegmentum [1]. It consists of complete ipsilateral horizontal gaze palsy (due to involvement of ipsilateral Paramedian Pontine Reticular Formation/Abducens Nucleus and Medial Longitudinal Fasciculus) and loss of adduction of the contralateral eye (due to involvement of the contralateral Medial Longitudinal Fasciculus). Extension of the lesion to the facial nucleus can produce ipsilateral lower motor neuron type facial palsy, leading to an even more uncommon 8.5 syndrome (7 + 1.5), described by Eggenberger in 1998 [2]. When the lesion involves the corticospinal tracts and/or the medial lemniscus, it can lead to contralateral hemiparesis and/or hemisensory deficits; the so called “9 syndrome” first proposed by Rosini et al in 2013 [3]. This rare entity has been reported in only a handful of cases. Conclusions The awareness of complex brainstem neuroanatomy enables precise localization of the clinical deficits. The noted slow progression of the clinical syndrome from 1.5 to 8.5 and finally 9 syndrome over 72 hours in this case highlights the complexity of small vessel brainstem ischemia.

Bilateral Facial Nerve Palsy as a Rare Presentation of Systemic Lupus Erythematosus

Abstract Systemic lupus erythematosus (SLE), a disease of the immune system, has a relapsing-remitting course. It is known to affect multiple organ systems of the body, including the nervous system. Cranial neuropathy, particularly facial neuropathy, is an unusual complication of SLE whose pathogenic mechanism is still not understood. Cardiac involvement, like myocarditis and papilledema, is another rare presentation of SLE. A 23-year-old male had bilateral lower motor neuron type of facial palsy which on a thorough investigation was found to be as a manifestation of SLE confirmed by antinuclear antibodies and double-stranded DNA antibody positive test. Electrocardiogram and echocardiography were suggestive of myocarditis. Fundus examination revealed Grade 2 papilledema. The patient was managed with symptomatic treatment along with corticosteroids, to which he responded gradually. Bilateral facial nerve lower motor neuron type palsy is a rare manifestation of SLE which should be diagnosed promptly and can be managed with corticosteroids. The clinician should also keep an eye on infrequent manifestations like myocarditis and papilledema.