Approach to gait disorders and orthotic management in adult onset neuromuscular diseases.

In order to understand abnormal gait, this article will first review normal gait, discuss how neuromuscular diseases disturb gait patterns and review orthotic interventions. In normal gait, concentric contractions accelerate and eccentric contractions decelerate the limb. Neuromuscular gait disorders can be grouped into (1) proximal weakness, (2) distal weakness, (3) nonlength-dependent or generalized weakness, (4) asymmetric weakness, and (5) sensory disorders. Identification of gait disturbance type in neuromuscular diseases leads to the appropriate orthotic prescription since orthotic strategies are grouped into (1) proximal weakness, (2) distal weakness, and (3) sensory disturbances. Orthotics is not indicated in all types of gait disturbance. Weakness in proximal hip musculature can be managed with gait aids such as walkers. In contrast, distal muscle weakness can be managed with orthotics. Preservation of gait assists in maintenance of daily function and integration in society.

Changes in the excitability of anterior horn cells in a mental rotation task of body parts.

INTRODUCTION/AIMS: Mental rotation (MR), a tool of implicit motor imagery, is the ability to rotate mental representations of two- or three-dimensional objects. Although many reports have described changes in brain activity during MR tasks, it is not clear whether the excitability of anterior horn cells in the spinal cord can be changed. In this study, we examined whether MR tasks of hand images affect the excitability of anterior horn cells using F-wave analysis. METHODS: Right-handed, healthy participants were recruited for this study. F-waves of the right abductor pollicis brevis were recorded after stimulation of the right median nerve at rest, during a non-MR task, and during an MR task. The F-wave persistence and the F/M amplitude ratio were calculated and analyzed. RESULTS: Twenty participants (11 men and 9 women; mean age, 29.2 ± 4.4 years) were initially recruited, and data from the 18 that met the inclusion criteria were analyzed. The F-wave persistence was significantly higher in the MR task than in the resting condition (p = .001) or the non-MR task (p = .012). The F/M amplitude ratio was significantly higher in the MR task than in the resting condition (p = .019). DISCUSSION: The MR task increases the excitability of anterior horn cells corresponding to the same body part. MR tasks may have the potential for improving motor function in patients with reduced excitability of the anterior horn cells, although this methodology must be further verified in a clinical setting.

The mystery of monozygotic twinning I: What can Amyoplasia tell us about monozygotic twinning and the possible role of twin-twin transfusion?

Amyoplasia is a very specific, nongenetic clinically recognizable form of arthrogryposis, representing about one-third of individuals with arthrogryposis surviving the newborn period. There is a markedly increased number of individuals with Amyoplasia who are one of monozygotic (MZ) twins, with the other twin being normal. Thus, it would appear that Amyoplasia is definitely associated with and may be caused by an MZ twinning event. The twin-twin transfusion seen in MZ twins could play an etiologic role in producing Amyoplasia. In this article, Amyoplasia twinning is compared to twinning in other forms of arthrogryposis. The accompanying paper examines various types of MZ twinning (Hall, 2021). Amyoplasia is primarily associated with spontaneous MZ twinning.

Curious case of steroid responsive diffuse anterior horn cell disease associated with COVID-19 infection.

Covid-19-associated neurological manifestations are being reported with increased frequency throughout the world. In a study from China, symptoms referable to peripheral nervous system (PNS) were described in approximately 9% of hospitalized Covid-19 patients. Common PNS symptoms reported in the study were loss of taste/smell and muscle pains. With this communication, we expand the spectrum of PNS manifestations of Covid-19 infection by reporting an association of steroid responsive diffuse anterior horn cell disease with Covid-19 infection from a tertiary care centre in India. Neurological manifestations of Covid-19 are diverse, and our case which to best of my knowledge is the first case in literature to report an occurrence of steroid responsive diffuse anterior horn cell disease associated with Covid-19 infection, adds to the ever-increasing spectrum of neurological manifestations associated with this pandemic causing virus. Good response to steroid in our case serves to provide an insight into the possible pathogenesis of this manifestation and also paves the way for future therapeutic decisions related to this association.

Acute flaccid paralysis due to Echovirus 30 in an immunosuppressed transplant recipient.

An Italian 13-year-old boy immunosuppressed due to kidney transplant presented in November 2018 with acute flaccid paralysis with anterior horn cell involvement resembling the clinical, radiological, and laboratory features of poliomyelitis. Enterovirus was molecularly identified in cerebral spinal fluid and stool samples and the sequence analysis of the VP1 gene of enterovirus genome revealed the presence of Echovirus 30 both in CSF and in stool samples. Echovirus 30 is an emerging neurotropic virus able to cause outbreaks of aseptic meningitis and meningoencephalitis all over the world, but acute flaccid paralysis is not a classical manifestation. A 6-month follow-up revealed a poor outcome with severe motor deficits and only slight improvement in disability. Clinicians must be aware of the possible role of Echovirus 30 in acute flaccid paralysis and active surveillance should consider the possible influence of immunosuppression on the symptoms caused by the widening spectrum of enterovirus infections.

Quantitative electromyography: Normative data in paraspinal muscles.

BACKGROUND: Quantitative electromyography of paraspinal muscle is a valuable diagnostic tool, but normative data are lacking. METHODS: Needle electromyography (EMG) was obtained in 65 healthy subjects (49% men, 51% women) aged 21 to 82 years at C7, Th10, and L5 segments bilaterally. The incidence of spontaneous activity; motor unit potential (MUP) amplitudes, durations, and the incidence of polyphasic potentials; and the recruitment pattern at maximal voluntary contraction (MVC) were evaluated. RESULTS: The incidence of fibrillation potentials was similar to limb muscles. The mean MUP duration and amplitude, and the amplitude at MVC increased caudally, while the incidence of polyphasic potentials was similar at all levels. EMG parameters did not correlate with sex or age. CONCLUSIONS: In contrast to limb muscles, EMG parameters did not change with age, while polyphasic potentials were more frequent in paraspinal muscle than in limb muscles. The EMG gradient suggests larger motor units at more caudal segments.

Ultrastructure of spinal anterior horn cells in human Niemann-Pick type C (NPC) patient and mouse model of NPC with retroposon insertion in NPC1 genes.

Niemann-Pick disease type C (NPC) is a neurovisceral lipid-storage disease. Although NPC patients show lipid storage in anterior horn cells of the spinal cord, little information is available regarding the electron microscopic analyses of the morphologies of intra-endosomal lipid like-materials in the anterior horn cells of NPC patients. In this study, we elucidated the intra-endosomal ultrastructures in spinal anterior horn cells in an NPC patient, as well as in mutant BALB/c NPC1-/- mice with a retroposon insertion in the NPC1 gene. These morphologies were classified into four types: vesicle, multiple concentric sphere (MCS), membrane, and rose flower. The percentages of the composition in the NPC patient and NPC1-/- mice were: vesicle (55.5% and 14.9%), MCS (15.7% and 3.4%), membrane (23.6% and 57.1%), and rose flower (5.2% and 24.6%), respectively. Formation of the intra-endosomal structures could proceed as follows: (i) a vesicle or MCS buds off the endosome into the lumen; (ii) when a vesicle breaks down, a membrane is formed; and (iii) after an MCS breaks down, a rose flower structure is formed. Our new finding in this study is that ultrastructural morphology is the same between the NPC patient and NPC1-/- mice, although there are differences in the composition.

Novel intracytoplasmic inclusions immunoreactive for phosphorylated-TDP43 and cystatin C in anterior horn cells in a case of sporadic amyotrophic lateral sclerosis.

Novel intracytoplasmic inclusions immunoreactive for phosphorylated transactivation response DNA-binding protein 43 (p-TDP43), cystatin C, and transferrin were found in anterior horn cells in a case of sporadic amyotrophic lateral sclerosis (ALS). The patient was a 59-year-old woman, who died of ALS after a clinical course of 8 years. She had been receiving mechanical support for respiration for 6 years and in a "totally locked-in" state for 4 years prior to death. The spinal cord showed severe degeneration involving the anterior and lateral funiculi, whereas the posterior funiculus was preserved. Neurons in the anterior horn and Clarke's column were markedly lost, and many Bunina bodies and a few skein-like inclusions were found. Some remaining anterior horn cells had round and densely eosinophilic or amphophilic intracytoplasmic inclusions. They were immunoreactive for ubiquitin, p-TDP43, cystatin C and transferrin. On confocal laser microscopy, cystatin C was found to consistently surround p-TDP43 within the inclusions. The inclusions ultrastructurally consisted of granule-associated fibrils and, in the central portion, dense aggregates of fibrils were associated with masses of electron-dense, coarsely granular or amorphous material. Although their pathogenesis remains unknown, these unique inclusions may have been formed under a specific condition whereby p-TDP43 and cystatin C interacted with each other.

A neurophysiological approach to nerve transfer to restore upper limb function in cervical spinal cord injury.

A successful nerve transfer surgery can provide a wealth of benefits to a patient with cervical spinal cord injury. The process of surgical decision making ideally uses all pertinent information to produce the best functional outcome. Reliance on clinical examination and imaging studies alone can miss valuable information on the state of spinal cord health. In this regard, neurophysiological evaluation has the potential to effectively gauge the neurological status of even select pools of anterior horn cells and their axons to small nerve branches in question to determine the potential efficacy of their use in a transfer. If available preoperatively, knowledge gained from such an evaluation could significantly alter the reconstructive surgical plan and avoid poor results. The authors describe their institution's approach to the assessment of patients with cervical spinal cord injury who are being considered for nerve transfer surgery in both the acute and chronic setting and broadly review the neurophysiological techniques used.

Colocalization of TDP-43 and stress granules at the early stage of TDP-43 aggregation in amyotrophic lateral sclerosis.

TDP-43 aggregates (skeins and round inclusions [RIs]) are frequent histopathological features of amyotrophic lateral sclerosis (ALS). We have shown that diffuse punctate cytoplasmic staining (DPCS) is the earliest pathologic manifestation of TDP-43 in ALS, corresponding to nonfibrillar TDP-43 located in the rough endoplasmic reticulum. Previous in vitro studies have suggested that TDP-43 inclusions may be derived from stress granules (SGs). Therefore, we investigated the involvement of SGs in the formation of TDP-43 inclusions. Formalin-fixed spinal cords of six ALS patients with a disease duration of less than 1 year (short duration), eight patients with a disease duration of 2-5 years (standard duration), and five normal controls were subjected to histopathological examination using antibodies against an SG marker, HuR. In normal controls, the cytoplasm of anterior horn cells was diffusely HuR-positive. In short-duration and standard-duration ALS, the number of HuR-positive anterior horn cells was significantly decreased relative to the controls. DPCS and RIs were more frequent in short-duration ALS than in standard-duration ALS. The majority of DPCS areas and a small proportion of RIs, but not skeins, were positive for HuR. Immunoelectron microscopy showed that ribosome-like granular structures in DPCS areas and RIs were labeled with anti-HuR, whereas skeins were not. These findings suggest that colocalization of TDP-43 and SGs occurs at the early stage of TDP-43 aggregation.

A Case Report and Review of Literature on Hirayama Disease.

Hirayama disease (HD) is a rare, benign, self-limiting condition that typically affects individuals in their 20s. Although the disease is self-limiting, it can result in functional impairment in those affected. The most common presentation is an asymmetrical, unilateral, or bilateral upper limb weakness with wasting. With an interesting pathogenesis and lack of definitive treatment, HD is an interesting neurological conundrum. Mild symptoms in patients often lead to underreporting of the disease, as individuals may not seek medical attention or may not recognize their symptoms. Most case reports in the literature are from Asia and the Middle East. We report a case of HD in a male patient in his 20s with gradual bilateral upper limb weakness and wasting, confirmed by imaging and nerve conduction studies.

Amyotrophic lateral sclerosis.

The scientific landscape surrounding amyotrophic lateral sclerosis has shifted immensely with a number of well-defined ALS disease-causing genes, each with related phenotypical and cellular motor neuron processes that have come to light. Yet in spite of decades of research and clinical investigation, there is still no etiology for sporadic amyotrophic lateral sclerosis, and treatment options even for those with well-defined familial syndromes are still limited. This chapter provides a comprehensive review of the genetic basis of amyotrophic lateral sclerosis, highlighting factors that contribute to its heritability and phenotypic manifestations, and an overview of past, present, and upcoming therapeutic strategies.

Childhood spinal muscular atrophy.

Spinal muscular atrophy (SMA) is caused by biallelic mutations in the SMN1 (survival motor neuron 1) gene on chromosome 5q13.2, which leads to a progressive degeneration of alpha motor neurons in the spinal cord and in motor nerve nuclei in the caudal brainstem. It is characterized by progressive proximally accentuated muscle weakness with loss of already acquired motor skills, areflexia and, depending on the phenotype, varying degrees of weakness of the respiratory and bulbar muscles. Over the past decade, disease-modifying therapies have become available based on splicing modulation of the SMN2 with SMN1 gene replacement, which if initiated significantly modifies the natural course of the disease. Newborn screening for SMA has been implemented in an increasing number of centers; however, available evidence for these new treatments is often limited to a small spectrum of patients concerning age and disease stage.

Late Onset Pompe Disease with Novel Mutations and Atypical Phenotypes.

BACKGROUND: Late onset Pompe disease (LOPD) is rare and generally manifests predominantly as progressive limb girdle muscle weakness. It is linked to the pathogenic mutations in GAA gene, which leads to glycogen accumulation in various tissues. MATERIALS AND METHODS: We describe the unusual clinical, biochemical, histopathological and genetic characteristics of 5 cases of LOPD. RESULTS: The first case had progressive anterior horn cell like disease (AHCD) that evolved later to classical limb girdle syndrome and respiratory failure, the second patient had rigid spine syndrome with gastrointestinal manifestations, the third had limb girdle weakness superimposed with episodic prolonged worsening and respiratory failure, the fourth had large fibre sensory neuropathy without primary muscle involvement and the fifth presented with classical limb girdle muscle weakness. Two homozygous missense mutations c.1461C > A (p.Phe487Leu) and c.1082C > T (p.Pro361Leu) in the GAA gene were identified in case 1 and 2 respectively. Case 3 was compound heterozygous with inframe c.1935_1940del (p.Val646_Cys647del) and an intronic splice effecting variant c.-32-13T > G. Compound heterozygous missense variants c.971C > T (p.Pro324Leu) and c.794G > A (p.Ser265Asn) were identified in case 4. Case 5 had a frameshift insertion c.1396dupG (p.Val466GlyfsTer40) and a synonymous splice affecting variant c.546G > T(p.Thr182=). CONCLUSION: We are describing for the first time from India on LOPD with unusual phenotypes identified. A high degree of clinical suspicion and diagnosing rare phenotypes of Pompe disease is imperative to consider early initiation of Enzyme Replacement Therapy (ERT).

General Anesthesia With Successful Immediate Post-operative Extubation for Sarcoma Excision in a 61-Year-Old Male With Kennedy's Disease.

Kennedy's disease (KD), also known as spinal and bulbar muscular atrophy (SBMA), is a rare, X-linked recessive androgen receptor gene mutation affecting approximately one in 40,000 males. A prominent anesthetic concern in patients with KD is their ability to maintain a patent airway following general anesthesia. We present the case of a 61-year-old man with a history of KD presenting for a left thigh sarcoma excision. The patient received a general anesthetic with endotracheal tube placement, was extubated in the operating room upon completion of the surgery, and had an uneventful post-operative course.

Nerve Conduction Study/Electromyography: Common Neuropathies and Considerations for Patients with Polio.

Acute poliomyelitis is now extremely rare in the United States. Worldwide there are still sporadic outbreaks, which are typically treated with acute inoculation programs. Although polio has effectively been eradicated, the full scope of the disease and its myriad manifestations both in the acute phase and in the postpolio syndrome phase, remain areas of fertile research, debate, and stimulating topics.

Benign monomelic amyotrophy of lower limb in a cohort of chinese patients.

BACKGROUND: Benign monomelic amyotrophy of lower limb (BMALL) is a neurogenic syndrome representing an unclear field. Further studies might be helpful to elucidate uncertainties regarding causation, outcome, and the risk of progression to amyotrophic lateral sclerosis (ALS). METHODS: According to the inclusion and exclusion criteria, 37 patients with BMALL were retrospectively collected in three neuromuscular centers from January 2012 to October 2018. The detailed medical data were summarized. Multiple laboratory tests were examined. Routine electrophysiological examinations, muscle MRI of lower limbs, and muscle biopsy were conducted. RESULTS: The cohort included 24 male and 13 female cases with median age of onset 47 years. Muscle MRI revealed that the distribution of involved muscles matched with the extent of fat infiltration, so the pattern muscle atrophy can be divided into the following four types: six patients with thigh atrophy (type I), 14 patients with leg atrophy (type II); 10 patients with disproportionate atrophy in both thigh and leg (type III); and seven patients with well-proportionate atrophy in both thigh and leg (type IV). Electrophysiological findings showed neurogenic pattern, spontaneous activity, and abnormal H reflex, which suggested a disorder of spinal anterior horn cell in the patients with types I-III. However, no electrophysiological abnormalities were found in the patients with type IV. Muscle pathology varied from almost normal pattern to advanced neurogenic pattern in nine biopsied patients. Follow-up showed that two patients with type II developed to ALS four years later, and all patients with type IV were in stable condition without any complaints. CONCLUSION: Muscle MRI was useful to exactly localize the distribution of involved muscles in BMALL patients. The distribution of atrophic muscles can be roughly divided into four types based on the MRI features. The classification of distributing types might be as an indicator for the prognosis of BMALL.

The diagnostic quandary of magnetic resonance imaging-negative Hirayama disease: a case report.

BACKGROUND: Magnetic resonance imaging (MRI) features are typical findings in Hirayama disease (HD) and are useful diagnostic entities but may not be present in all patients. CASE PRESENTATION: We present the case of a 22-year-old Nepalese man who presented with insidious onset of weakness of his right upper limb of more than 5 years duration. His weakness was progressive for the first 3 years, and then remained static. On examination, weakness of the interossei, thenar, hypothenar, flexor, and extensor muscles were present in his right upper limb, power was normal in his left upper and bilateral lower limbs. Minipolymyoclonus was present in both upper limbs, less prominent on the left side. Electrophysiological findings showed motor axonal neuropathy in his right upper limb, neurogenic discharges and fibrillations, and fasciculations in both upper limbs. Contrast magnetic resonance imaging (MRI) of his cervical spine in flexion was normal. Our patient was diagnosed with HD based on clinical and electrophysiological findings. Our patient was advised to use a cervical collar and regular physiotherapy and was found to have subjective benefit. CONCLUSION: A normal cervical MRI does not rule out HD and the diagnosis can also be made based on clinical and electrophysiological studies. Progressive distal upper limb weakness or tremor in young patients should be evaluated for HD, because early diagnosis and intervention might halt the progression.