The Spontaneous Incidence of Neurological Clinical Signs in Preclinical Species Using Cage-side Observations or High-definition Video Monitoring: A Retrospective Analysis

When conducting toxicology studies, the interpretation of drug-related neurological clinical signs such as convulsions, myoclonus/myoclonic jerks, tremors, ataxia, and salivation requires an understanding of the spontaneous incidence of those observations in commonly used laboratory animal species. The spontaneous incidence of central nervous system clinical signs in control animals from a single facility using cage-side observations or high definition video monitoring was retrospectively analyzed. Spontaneous convulsions were observed at low incidence in Beagle dogs and Sprague-Dawley rats but were not identified in cynomolgus monkeys and Göttingen minipigs. Spontaneous myoclonic jerks and muscle twitches were observed at low incidence in Beagle dogs, cynomolgus monkeys, and Sprague-Dawley rats but were not seen in Göttingen minipigs. Spontaneous ataxia/incoordination was identified in all species and generally with a higher incidence when using video monitoring. Salivation and tremors were the two most frequent spontaneous clinical signs and both were observed in all species. Data from the current study unveil potential limitations when using control data obtained from a single study for toxicology interpretation related to low incidence neurological clinical signs while providing historical control data from Beagle dogs, cynomolgus monkeys, Sprague-Dawley rats, and Göttingen minipigs.

Late infantile and adult-onset metachromatic leukodystrophy due to novel missense variants in the PSAP gene: Case report from India

Metachromatic leukodystrophy (MLD) due to Sap-B deficiency is a rare autosomal recessive disorder caused due to biallelic variants in the PSAP gene. The PSAP gene encodes a precursor protein prosaposin, which is subsequently cleaved to form four active glycoproteins: Sap-A, Sap-B, Sap-C, and Sap-D. In case of deficiency of the sphingolipid activator protein Sap-B, there is a gradual accumulation of cerebroside-3-sulfate in the myelin of the nervous system resulting in progressive demyelination. Only 12 variants have been reported in the PSAP gene causing Sap-B deficiency to date. Here, we report two cases of MLD due to Sap-B deficiency (late-infantile and adult-onset form) harboring two novel missense variants c.688T > G and c.593G > A in the PSAP gene respectively. This study reports the third case of adult-onset MLD due to Sap-B deficiency in the world. The proband, a 3-year-old male child presented with complaints of hypotonia, lower limb tremors and global developmental delay. His MRI showed hyperintense signals in the bilateral cerebellar white matter. Overall, the findings were suggestive of metachromatic leukodystrophy. The second case was a 19-year-old male child with clinical features of regression of speech, gait ataxia and bilateral tremors referred to our clinic. MRI data suggested metachromatic leukodystrophy. Normal enzyme activity of arylsulfatase-A led to a suspicion of saposin B deficiency. For both cases, targeted sequencing was performed. This identified homozygous variant c.688T > G (p.Cys230Gly) and c.593G > A (p.Cys198Tyr) in exon 6 of the PSAP gene, respectively.

Use of haemodiafiltration in the treatment of massive caffeine intoxication in a dog

The objective of this case report is to describe the use of extracorporeal therapy, specifically hemodialfiltration, for the treatment of caffeine intoxication. A 12 year old Border Terrier consumed up to 1440 mg/kg of caffeine and rapidly developed clinical signs of tachycardia and tremors. Hemodiafiltration was instituted, using an M60 PrismaFlex cartridge using blood to prime the system due to patient size. Treatment with 11.25 L of therapy fluid (83% dialysate, 17% replacement fluid), or 1.8 L/kg, was provided over 6 h. Pre-treatment serum caffeine concentration of 233 µg/mL was decreased by 89% to 25 µg/nL by the end of treatment. Despite prompt institution of extracorporeal toxin removal therapy, ventricular ectopy developed necessitating sotolol treatment for the following week. Caffeine is efficiently removed via hemodialysis, as predicted by small size, small volume of distribution, and minimal protein binding. A CRRT platform can be used to provide adequate clearance.

A Case of Hypoparathyroidism in Type 1 Diabetes Mellitus

This case report discusses a 13-year-old female with a known history of type 1 diabetes mellitus presenting with pain in bilateral lower limbs, generalized weakness, and fatigue. After laboratory examinations, hypoparathyroidism was diagnosed based on low serum calcium, elevated serum phosphorous, and lower serum intact parathyroid hormone (PTH) levels. Treatment with calcium and vitamin D supplements led to a reduction in the patient's symptoms. The report provides an overview of the pathophysiology of hypoparathyroidism, its various etiologies, and clinical manifestations. The report emphasizes the importance of considering hypoparathyroidism as a differential diagnosis in patients with unexplained neuromuscular symptoms, even without a known thyroid disease or previous thyroid surgery.

Role of Gamma Knife Radiosurgery in the Management of Functional Disorders - A Literature Review

Background

Role of radiosurgical lesioning in functional disorders has been restricted because of development of deep brain stimulation (DBS) techniques. However, many elderly patients with comorbidities and coagulation abnormalities may not be eligible for DBS. Radiosurgical lesioning may be a good alternative in such cases. The objective of the study was to review the role of radiosurgical lesioning for functional targets in common functional disorders.

Materials and Methods

Literature reports pertaining to common disorders were reviewed. Disorders included are tremors (essential tremors, tremor-dominant Parkinson's disease [PD], multiple sclerosis [MS] related refractory tremors), Parkinson's disease (for rigidity, bradykinesia, drug-induced dyskinesias), dystonia, and obsessive-compulsive disorder (OCD).

Results

The most commonly performed procedure was ventral intermediate nucleus (VIM) lesioning for essential tremors and tremor-dominant PD, with about 90% patients demonstrating improvement. Intractable OCD with 60% responders is a promising indication. Other disorders are less commonly treated, with dystonia being the least commonly treated entity. Subthalamic nucleus (STN) and globus pallidus interna/posteroventral pallidum (GPi) lesioning are very rarely reported, and the available literature suggests caution due to high rates of adverse effects.

Conclusions

Outcomes for radiosurgical lesioning for essential tremors (VIM) and OCD (anterior limb of internal capsule [ALIC]) are encouraging. Radiosurgical lesioning offers a lower immediate risk profile in patient population with several comorbidities; however, long-term adverse effects due to radiation are a concern, especially for STN and GPi lesioning.

Case report: Amphiphysin-IgG autoimmunity: a paraneoplastic presentation of appendiceal goblet cell carcinoma

Background

Appendiceal goblet cell carcinoma (aGCC) is a rare neoplasm with mixed endocrine and exocrine features. No paraneoplastic neurological syndromes or autoantibodies have been identified in cases of aGCC or even appendiceal tumors. Amphiphysin-immunoglobulin G (IgG) autoimmunity was first described in stiff-person syndrome with breast cancer. We firstly described the clinical course and pathological findings of a patient with aGCC-associated amphiphysin-IgG autoimmunity.

Case presentation

A 54-year-old man who developed aGCC was admitted for acute disturbance of consciousness, psychiatric symptoms, cognitive impairment, seizure and hypotension. Amphiphysin-IgG was detected in the patient's serum and CSF by immunoblotting and tissue-based indirect immunofluorescence assay confirming the diagnosis of definite paraneoplastic amphiphysin-IgG-positive encephalitis. Histopathology revealed amphiphysin protein expression and accompanying immune cell infiltration (predominantly CD20+ B cells, CD3+ and CD8+ T cells) within the tumor tissue, suggesting a possible paraneoplastic origin of amphiphysin-associated paraneoplastic neurological syndromes (PNSs) in this case. Although the patient's symptoms resolved after high-dose corticosteroid therapy, he experienced recurrence 6 months later, manifesting as paraneoplastic cerebellar dysfunction. Despite treatment with IV cyclophosphamide and oral mycophenolate mofetil, no improvement was noted.

Conclusions

This case suggests that aGCC may trigger amphiphysin-IgG autoimmunity.

Tremors: A concept analysis

AIM

This article seeks to clarify and define the concept of tremors.

DESIGN

The Walker & Avant (2005) concept analysis method was followed.

METHODS

A search of PubMed, Academic Search Complete, CINAHL, ERIC, Google and Google Scholar was performed.

RESULTS

Through this process, uses of the concept were assessed including definitions and categories of tremors. Defining attributes were found to include "movement disorder," "shaking motions," "involuntary," "oscillatory," "rhythmic," "not painful or life threatening," "always present but variable" and "can sometimes be repressed." We identified two model cases and a borderline case, antecedents, consequences and empirical referents (including measurement tools) of tremors.

CONCLUSION

The concept analysis process has clarified and illuminated an operational definition of tremors: that tremors are a movement disorder characterized by shaking motions that are involuntary, oscillatory, rhythmic, non-painful, always present although vary in severity, and can be repressed by changing posture or going into a rest position.

Post Severe Acute Respiratory Syndrome Coronavirus 2 Infection Tremors in a Nonverbal Autistic Adolescent

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) pandemic in 2020 remains a major public health challenge until mass vaccination. The number of SARS-CoV-2 positive children aged 0-17 years has been increasing as older adults are vaccinated. Infected children tend to have less severe illness compared with adults, have predominantly respiratory or GI symptoms, or no symptoms. Children have an increased risk for multisystem inflammatory syndrome in children (MIS-C), which is unique. Neuropsychological complications of COVID-19 remain uncommon. Case reports and data from series exist. We report a case of tremors as sequelae of SARS-CoV-2 infection in a non-verbal adolescent with autism spectrum disorder (ASD).

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson’s disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Protein Interaction Studies for Understanding the Tremor Pathway in Parkinson's Disease

BACKGROUND

Tremor is one of the most noticeable features, which occurs during the early stages of Parkinson's Disease (PD). It is one of the major pathological hallmarks and does not have any interpreted mechanism. In this study, we have framed a hypothesis and deciphered protein- protein interactions between the proteins involved in impairment in sodium and calcium ion channels and thus cause synaptic plasticity leading to a tremor.

METHODS

Literature mining for retrieval of proteins was done using Science Direct, PubMed Central, SciELO and JSTOR databases. A well-thought approach was used, and a list of differentially expressed proteins in PD was collected from different sources. A total of 71 proteins were retrieved, and a protein interaction network was constructed between them by using Cytoscape.v.3.7. The network was further analysed using the BiNGO plugin for retrieval of overrepresented biological processes in Tremor-PD datasets. Hub nodes were also generated in the network.

RESULTS

The Tremor-PD pathway was deciphered, which demonstrates the cascade of protein interactions that might lead to tremors in PD. Major proteins involved were LRRK2, TUBA1A, TRAF6, HSPA5, ADORA2A, DRD1, DRD2, SNCA, ADCY5, TH, etc. Conclusion: In the current study, it is predicted that ADORA2A and DRD1/DRD2 are equally contributing to the progression of the disease by inhibiting the activity of adenylyl cyclase and thereby increases the permeability of the blood-brain barrier, causing an influx of neurotransmitters and together they alter the level of dopamine in the brain which eventually leads to tremor.

Possible Association of Tremors and Dysarthria with Losartan Use: A Case Report

Losartan is a common first-line antihypertensive medication particularly useful in a select patient population. Common side effects of the drug include headaches, dizziness, fatigue, nausea, vomiting, and anemia. The only well-documented detrimental side effect of losartan is angioedema/anaphylactoid reactions. Here, we present a case of a 56-year-old Caucasian male who developed tremors and dysarthria one hour after taking losartan. His symptoms were severe enough to require hospitalization and close monitoring. His symptoms later resolved without any targeted treatment. This is the first reported case of tremors and dysarthria associated with the use of losartan which could represent an entirely benign side effect or an initial sequela of a potentially detrimental side effect that warrants our attention.

Juvenile Parkinson Disease

Juvenile Parkinson's disease (JPD) is a rare movement disorder that presents before the age of 21 years. Kufor-Rekab syndrome (KRS) is one of the distinct types of JPD caused by the ATP13A2 mutation and inherited as an autosomal recessive. The pathogenesis of KRS is related to an interrelated metabolism of ATP13A2 with Mn+2 and Zn+2, bioenergetics of mitochondria, autophagy lysosomal dysfunction, and synuclein metabolism. Clinically, KRS has a variable phenotype and may present with pyramidal or extrapyramidal symptoms and cognitive impairment. Early diagnosis of KRS is important as most of these patients are levodopa-responsive and genetic counseling and screening is important for the whole family. We present a case of a 16-year-old boy who presented with tremors and walking difficulty. His physical examination showed an expressionless face, decrease in eye blink frequency, and slow vertical saccadic eye movements. His movements were slow. All laboratory investigations were normal, except the genetic study, which led to the diagnosis of KRS.

Infantile tremor syndrome: current perspectives

Infantile Tremor Syndrome (ITS) is a self-limiting clinical state characterized by tremors, anemia, pigmentary skin disease, regression of mental development, and hypotonia of muscles in a plump looking child. Tremors are coarse in character, decreased or disappeared in sleep and resolves within 4-6 weeks in its natural course. Various etiological factors as infectious, metabolic, nutritional have been hypothesized but none is conclusive. Consensus is developing on the role of Vitamin B12 deficiency in children with ITS but is still debatable. Empirical management of ITS children has been tried in the absence of exact etiology considering child as undernourished. Nutritional management includes supplementation of Iron, Calcium, Magnesium, Vitamin B12 and other multivitamins. Tremors can be managed with administration of propranolol most commonly or phenobarbitone, phenytoin, and carbamazepine.

The Effect of Physical Activity in Parkinson's Disease: A Mini-Review

This article will discuss the effects of physical activity in patients with Parkinson's disease. Presently, the motor and non-motor symptoms are difficult to treat with the current treatment of Parkinson's; therefore, as an adjuvant to the current treatment physical activity, has been recommended. Physical activity has been known to improve many symptoms in patients with Parkinson's disease. Some of these symptoms include the physical capacities, physical and cognitive functional capacities. Physical activity also slows the disease process, decreases the pain associated with Parkinson`s disease, prolongs the independent mobility (gait, balance, strength) and improves sleep, mood, memory hence improving the overall quality of life. Furthermore, physical activity has the potential to improve the non-motor symptoms (depression, apathy, fatigue, constipation) and the secondary complications of immobility (cardiovascular, osteoporosis) in Parkinson's disease.

Development and validation of a yoga module for Parkinson disease

Background Parkinson's disease (PD), a progressive neurodegenerative disease, affects motor and nonmotor functions, leading to severe debility and poor quality of life. Studies have reported the beneficial role of yoga in alleviating the symptoms of PD; however, a validated yoga module for PD is unavailable. This study developed and validated an integrated yoga module(IYM) for PD. Methods The IYM was prepared after a thorough review of classical yoga texts and previous findings. Twenty experienced yoga experts, who fulfilled the inclusion criteria, were selected validating the content of the IYM. A total of 28 practices were included in the IYM, and each practice was discussed and rated as (i) not essential, (ii) useful but not essential, and (iii) essential; the content validity ratio (CVR) was calculated using Lawshe's formula. Results Data analysis revealed that of the 28 IYM practices, 21 exhibited significant content validity (cut-off value: 0.42, as calculated by applying Lawshe's formula for the CVR). Conclusions The IYM is valid for PD, with good content validity. However, future studies must determine the feasibility and efficacy of the developed module.

An ICU nurse with a history of tremors

A 52-year-old female working as a registered nurse in the ICU developed tremors with fine motor activities in stressful situations. She was evaluated by a neurologist and was diagnosed with physiological tremors. Implications for practice are explored.

Sotos syndrome: An unusual presentation with intrauterine growth restriction, generalized lymphedema, and intention tremor

Sotos syndrome is a childhood overgrowth syndrome characterized clinically by a distinctive facial gestalt, advanced bone age, childhood overgrowth, and non-progressive developmental delay; and genetically by haploinsufficiency of the Nuclear receptor binding SET Domain 1 (NSD1) gene. Generalized lymphedema has not previously been associated with Sotos syndrome. Generalized lymphedema has been associated with mutations in several genes including FLT4. This gene is involved in the regulation of VEGFR3, a key governor of lymphatic-endothelial cell development and function. We report on a 28-year-old Caucasian female with a de novo NSD1 intragenic mutation, c.5841_5848dup: p.Leu1950Serfs*22, who presented with characteristic clinical features of Sotos syndrome. Unusually this case includes atypical features of intrauterine growth retardation and post-pubertal onset of primary lymphedema. To our knowledge, no link between Sotos syndrome and generalized lymphedema has previously been described in the literature. We propose a mechanism by which disruptions in NSD1 gene may lead to generalized lymphedema. Aberrations of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)-signaling pathway has been identified in both Sotos syndrome and lymphedema. This finding extends the known phenotype of Sotos syndrome through the inclusion of lymphedema. This case also indicates that presence of low birth weight does not exclude the possibility of Sotos syndrome.

Extrapyramidal effects of acute organophosphate poisoning

BACKGROUND

There is limited information on extrapyramidal symptoms in acute organophosphate (OP) poisoning. We describe the course and outcome of severely poisoned patients who develop extrapyramidal manifestations.

METHODS

In this prospective observational study, spanning 8 months (Apr-Nov 2013) adult patients (>18 years) admitted with OP poisoning were enrolled. Patients on anti-psychotic therapy, those refusing consent or presenting with co-ingestions were excluded. Treatment included atropine and supportive care (e.g. ventilation and inotropes as indicated); oximes were not administered. The presence of rigidity, tremors, dystonia and chorea were assessed daily till discharge using modifications of the Unified Parkinson's Disease rating scale and the Tremor rating scale. The presence of extrapyramidal manifestations was correlated with length of ventilation and hospital stay and mortality.

RESULTS

Of the 77 patients admitted with OP poisoning, 32 were enrolled; 17 (53.1%) developed extrapyramidal manifestations which included rigidity (94.1%), tremors (58.8%) and dystonia (58.8%). None developed chorea. The median (inter-quartile range) time of symptom onset was 8 (5-11) days; extrapyramidal features resolved in 11 (6-17) days. The median duration of intensive care stay in patients not developing extrapyramidal symptoms was 6 (2-8) days, indicating that most of these patients had recovered even before symptom onset in patients who developed extrapyramidal manifestations. Overall, 27/32 (84%) were ventilated. Hospital mortality was 6.25% (2/32). When compared with patients not developing extrapyramidal signs, those with extrapyramidal manifestations had significantly prolonged ventilation (5 versus 16 median days; p = 0.001) and hospitalization (8 versus 21 days; p < 0.001), reduced ventilator-free days (23 versus 12 days; p = 0.023) and increased infections (p = 0.03). The need for ventilation and mortality were not significantly different (p > 0.6). Extrapyramidal symptoms were not observed in non-OP poisoned patients with prolonged ICU stay.

CONCLUSION

In this small series of acute OP poisoning, extrapyramidal manifestations were common after 1 week of intensive care but self-limiting. They are significantly associated with longer duration of ventilation and hospital stay.

The changing profile of infantile tremor syndrome in hilly terrain of India

BACKGROUND

Infantile tremor syndrome (ITS) is characterized by anemia, skin pigmentation, tremors, physical, and mental regression without a defined etiopathogenesis and low incidence.

MATERIALS AND METHODS

We have studied 9 patients over 1 year for the changing clinical and laboratory variables of patients with ITS. Neuroregression and anemia were presented in all followed by tremors in 5 and hypotonia in 2.

RESULT

Sepsis screen was positive in 6 and urine cultures in 2. Antibiotics were required in 6. ITS with changing parameters still significantly contributes to healthcare burden.

CONCLUSION

It is important to screen for urinary infection and septicemia to avoid antibiotic abuse.

The neurotoxicity of organochlorine and pyrethroid pesticides

Organochlorine and pyrethroid compounds represent an old and a new class, respectively, of insecticides. Organochlorines such as DDT, dieldrin, or chlordecone, have been banned, primarily because of environmental issues. DDT is still used in certain countries to fight malaria-bearing mosquitoes, while lindane still finds some limited used against head lice. In contrast, pyrethroids find widespread use because of their efficacy, low environmental persistence, and relatively low mammalian toxicity. Like all insecticides, organochlorines and pyrethroids target the nervous system of insects and of nontarget species. All pyrethroids and DDT interact with the sodium channel; by keeping it open longer, they increase the likelihood of action potentials developing, thus creating a condition of hyperexcitability, whose main clinical sign is tremors. Most other organochlorines (except chlordecone), as well as certain (type II) pyrethroids, block the chloride channels of the GABA-A receptor, and cause seizures. Evidence of an association between exposure to organochlorine and pyrethroid insecticides and neurodegenerative diseases (e.g., Parkinson's disease) is weak, at best.

The potential roles of T-type Ca2+ channels in motor coordination

Specific behavioral patterns are expressed by complex combinations of muscle coordination. Tremors are simple behavioral patterns and are the focus of studies investigating motor coordination mechanisms in the brain. T-type Ca(2+) channels mediate intrinsic neuronal oscillations and rhythmic burst spiking, and facilitate the generation of tremor rhythms in motor circuits. Despite substantial evidence that T-type Ca(2+) channels mediate pathological tremors, their roles in physiological motor coordination and behavior remain unknown. Here, we review recent progress in understanding the roles that T-type Ca(2+) channels play under pathological conditions, and discuss the potential relevance of these channels in mediating physiological motor coordination.

Slowly progressive aphasia with striatal involvement

We have described four patients with slowly progressive aphasia with striatal involvement occurring at different stages in the course of the illness. There were two males and two females, and their ages ranged from 68 to 76 (mean: 72) years. The extrapyramidal signs included tremors, bradykinesia, rigidity, and focal dystonia, and one had weakness resembling stroke. There is a heterogeniety among patients with slowly progressive aphasia and the clinical features correspond to the functional anatomy of the areas involved rather than to the pathology.