Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by low levels of full-length survival motor neuron (SMN) protein due to the loss of the survival motor neuron 1 (SMN1) gene and inefficient splicing of the survival motor neuron 2 (SMN2) gene, which mostly affects alpha motor neurons of the lower spinal cord. Despite the U.S. Food and Drug Administration (FDA) approved SMN-dependent therapies including Nusinersen, Zolgensma® and Evrysdi™, SMA is still a devastating disease as these existing expensive drugs may not be sufficient and thus, remains a need for additional therapies. The involvement of microRNAs (miRNAs) in SMA is expanding because miRNAs are important mediators of gene expression as each miRNA could target a number of genes. Hence, miRNA-based therapy could be utilized in treating this genetic disorder. However, the delivery of miRNAs into the target cells remains an obstacle in SMA, as there is no effective delivery system to date. This review highlights the potential strategies for intracellular miRNA delivery into target cells and current challenges in miRNA delivery. Furthermore, we provide the future prospects of miRNA-based therapeutic strategies in SMA.
Bell's palsy is a benign lower motor neuron facial nerve disorder. It is almost always unilateral. We report a 20-year-old nulliparous woman with five episodes of recurrent Bell's palsy. A review of recent medical literature revealed a paucity of case reports involving an individual with five episodes of recurrent Bell's palsy, with none found in Asian neurology medical literature. Despite the multiple episodes of Bell's palsy recurrences, the patient did not suffer much neurological sequelae from the disease.
The electrodiagnosis of Guillain-Barré syndrome (GBS) can be broadly divided into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Fisher syndrome (FS) is a variant of GBS, although the underlying neuropathy of FS has yet to be established. Serial nerve conduction studies (NCS) can provide further insight into the likely pathophysiology by further subtyping of GBS and FS. We present a patient with an initial diagnosis of AIDP in whom repeated NCS revealed the AMAN variant. This led us to investigate serial NCS in five patients with GBS, FS and FS/GBS overlap presenting over a period of a year. Three patients with AIDP showed a gradual increase in distal motor latencies during the acute phase of illness. NCS of two patients with FS and FS/GBS overlap showed no demyelinating features suggesting underlying axonal neuropathy in this group of patients. The importance of serial NCS in establishing the underlying pattern of neuropathy in GBS and FS is further emphasized in this study. Larger studies incorporating serial NCS are required to confirm the observations seen in our case series especially when pathological studies are often not justified in this group of patients.
Cervical spondylotic myelopathy (CSM) represents a spectrum of pathologies with progressive compression of the spinal cord. The clinical signs and symptoms play a key role in diagnosis. The characteristic hand myelopathy signs are of significant clinical importance. The aim of this descriptive study was to report a relatively easy to elicit new hand myelopathy sign. The basis for this is finger and wrist flexor disinhibition, which is used for the spinal specificity of cord compression at or above the C5/6 level.
Amyotrophic lateral sclerosis (ALS) is a devastating and rapidly progressing neurodegenerative disorder with no effective disease-modifying treatment up to date. The underlying molecular mechanisms of ALS are not yet completely understood. However, the critical role of the innate immune system and neuroinflammation in ALS pathogenesis has gained increased attention. High mobility group box 1 (HMGB1) is a typical damage-associated molecular pattern (DAMP) molecule, acting as a pro-inflammatory cytokine mainly through activation of its principal receptors, the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4) which are crucial components of the innate immune system. HMGB1 is an endogenous ligand for both RAGE and TLR4 that mediate its biological effects. Herein, on the ground of pre-clinical findings we unravel the underlying mechanisms behind the plausible contribution of HMGB1 and its receptors (RAGE and TLR4) in the ALS pathogenesis. Furthermore, we provide an account of the therapeutic outcomes associated with inhibition/blocking of HMGB1 receptor signalling in preventing motor neuron's death and delaying disease progression in ALS experimental models. There is strong evidence that HMGB1, RAGE and TLR4 signaling axes might present potential targets against ALS, opening a novel headway in ALS research that could plausibly bridge the current treatment gap.
Clinical studies and research in animals have established that alcohol consumption during pregnancy produces irreversible developmental anomalies. Deficits in fine motor performance are often noted in infants diagnosed with fetal alcohol syndrome. However, the effects of alcohol on the spinal motoneurons have not been examined. In this study, the morphometric alterations in spinal motoneurons were assessed as a result of prenatal alcohol exposure.