Mechanical properties of epithelial cells in domes investigated using atomic force microscopy.

As epithelial cells in vitro reach a highly confluent state, the cells often form a microscale dome-like architecture that encloses a fluid-filled lumen. The domes are stabilized by mechanical stress and luminal pressure. However, the mechanical properties of cells that form epithelial domes remain poorly characterized at the single-cell level. In this study, we used atomic force microscopy (AFM) to measure the mechanical properties of cells forming epithelial domes. AFM showed that the apparent Young's modulus of cells in domes was significantly higher when compared with that in the surrounding monolayer. AFM also showed that the stiffness and tension of cells in domes were positively correlated with the apical cell area, depending on the degree of cell stretching. This correlation disappeared when actin filaments were depolymerized or when the ATPase activity of myosin II was inhibited, which often led to a large fluctuation in dome formation. The results indicated that heterogeneous actomyosin structures organized by stretching single cells played a crucial role in stabilizing dome formation. Our findings provide new insights into the mechanical properties of three-dimensional deformable tissue explored using AFM at the single-cell level.

Neural mechanisms to incorporate visual counterevidence in self-movement estimation.

In selecting appropriate behaviors, animals should weigh sensory evidence both for and against specific beliefs about the world. For instance, animals measure optic flow to estimate and control their own rotation. However, existing models of flow detection can be spuriously triggered by visual motion created by objects moving in the world. Here, we show that stationary patterns on the retina, which constitute evidence against observer rotation, suppress inappropriate stabilizing rotational behavior in the fruit fly Drosophila. In silico experiments show that artificial neural networks (ANNs) that are optimized to distinguish observer movement from external object motion similarly detect stationarity and incorporate negative evidence. Employing neural measurements and genetic manipulations, we identified components of the circuitry for stationary pattern detection, which runs parallel to the fly's local motion and optic-flow detectors. Our results show how the fly brain incorporates negative evidence to improve heading stability, exemplifying how a compact brain exploits geometrical constraints of the visual world.

Long-timescale anti-directional rotation in Drosophila optomotor behavior.

Locomotor movements cause visual images to be displaced across the eye, a retinal slip that is counteracted by stabilizing reflexes in many animals. In insects, optomotor turning causes the animal to turn in the direction of rotating visual stimuli, thereby reducing retinal slip and stabilizing trajectories through the world. This behavior has formed the basis for extensive dissections of motion vision. Here, we report that under certain stimulus conditions, two Drosophila species, including the widely studied Drosophila melanogaster, can suppress and even reverse the optomotor turning response over several seconds. Such 'anti-directional turning' is most strongly evoked by long-lasting, high-contrast, slow-moving visual stimuli that are distinct from those that promote syn-directional optomotor turning. Anti-directional turning, like the syn-directional optomotor response, requires the local motion detecting neurons T4 and T5. A subset of lobula plate tangential cells, CH cells, show involvement in these responses. Imaging from a variety of direction-selective cells in the lobula plate shows no evidence of dynamics that match the behavior, suggesting that the observed inversion in turning direction emerges downstream of the lobula plate. Further, anti-directional turning declines with age and exposure to light. These results show that Drosophila optomotor turning behaviors contain rich, stimulus-dependent dynamics that are inconsistent with simple reflexive stabilization responses.

A novel HECW2 variant in an infant with congenital long QT syndrome.

Pathogenic variants of HECW2 have been reported in cases of neurodevelopmental disorder with hypotonia, seizures, and absent language (NDHSAL; OMIM #617268). A novel HECW2 variant (NM_001348768.2:c.4343 T > C,p.Leu1448Ser) was identified in an NDHSAL infant with severe cardiac comorbidities. The patient presented with fetal tachyarrhythmia and hydrops and was postnatally diagnosed with long QT syndrome. This study provides evidence that HECW2 pathogenic variants can cause long QT syndrome along with neurodevelopmental disorders.

Pathogenic Roles of Cardiac Fibroblasts in Pediatric Dilated Cardiomyopathy.

Background Dilated cardiomyopathy (DCM) is a major cause of heart failure in children. Despite intensive genetic analyses, pathogenic gene variants have not been identified in most patients with DCM, which suggests that cardiomyocytes are not solely responsible for DCM. Cardiac fibroblasts (CFs) are the most abundant cell type in the heart. They have several roles in maintaining cardiac function; however, the pathological role of CFs in DCM remains unknown. Methods and Results Four primary cultured CF cell lines were established from pediatric patients with DCM and compared with 3 CF lines from healthy controls. There were no significant differences in cellular proliferation, adhesion, migration, apoptosis, or myofibroblast activation between DCM CFs compared with healthy CFs. Atomic force microscopy revealed that cellular stiffness, fluidity, and viscosity were not significantly changed in DCM CFs. However, when DCM CFs were cocultured with healthy cardiomyocytes, they deteriorated the contractile and diastolic functions of cardiomyocytes. RNA sequencing revealed markedly different comprehensive gene expression profiles in DCM CFs compared with healthy CFs. Several humoral factors and the extracellular matrix were significantly upregulated or downregulated in DCM CFs. The pathway analysis revealed that extracellular matrix receptor interactions, focal adhesion signaling, Hippo signaling, and transforming growth factor-ß signaling pathways were significantly affected in DCM CFs. In contrast, single-cell RNA sequencing revealed that there was no specific subpopulation in the DCM CFs that contributed to the alterations in gene expression. Conclusions Although cellular physiological behavior was not altered in DCM CFs, they deteriorated the contractile and diastolic functions of healthy cardiomyocytes through humoral factors and direct cell-cell contact.

Clinical characteristics of muscle cramps in hereditary angiopathy with nephropathy, aneurysms, and muscle cramps syndrome associated with a novel COL4A1 pathogenic variant: A family case study.

BACKGROUND: Muscle cramps are a common problem characterized by a sudden, painful, and involuntary contraction of a muscle or muscle group. Most muscle cramps develop in the calf muscles, particularly in situations of prolonged exercise; however, some may be related to underlying systemic conditions such as the hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome. Muscle cramps appear to be the initial symptom of the HANAC syndrome; however, the clinical characteristics of these muscle cramps have rarely been described in detail. CASE PRESENTATION: We report a familial case of autosomal-dominant muscle cramps in four members of a Japanese family spanning across three generations. The muscle cramps were recognized as systemic symptoms of the HANAC syndrome associated with a novel COL4A1 pathogenic variant, NM_001845:c.1538G > A, p.(Gly513Asp). The four affected individuals indicated that the first episodes of the muscle cramps occurred in early childhood. In addition, they reported that the muscle cramps are characterized by an abrupt onset of severe pain without muscle contraction. The painful recurrent attacks occurred spontaneously in various muscles throughout the body, but rarely in the calf muscle. The muscle pain lasts for several minutes, cannot be ameliorated by stretching the affected muscle, and leaves a feeling of discomfort that lasts for 24-48 h. The serum creatine kinase levels of the patients were persistently elevated; however, their electromyography results did not reveal any specific abnormalities. CONCLUSIONS: Recognition of the clinical characteristics of the muscle cramps in the HANAC syndrome may facilitate early diagnosis of the syndrome and enable proper treatment of the patients, improve their long-term outcomes, and facilitate the design and adaption of appropriate genetic counseling.

Long timescale anti-directional rotation in Drosophila optomotor behavior.

Locomotor movements cause visual images to be displaced across the eye, a retinal slip that is counteracted by stabilizing reflexes in many animals. In insects, optomotor turning causes the animal to turn in the direction of rotating visual stimuli, thereby reducing retinal slip and stabilizing trajectories through the world. This behavior has formed the basis for extensive dissections of motion vision. Here, we report that under certain stimulus conditions, two Drosophila species, including the widely studied D. melanogaster, can suppress and even reverse the optomotor turning response over several seconds. Such "anti-directional turning" is most strongly evoked by long-lasting, high-contrast, slow-moving visual stimuli that are distinct from those that promote syn-directional optomotor turning. Anti-directional turning, like the syn-directional optomotor response, requires the local motion detecting neurons T4 and T5. A subset of lobula plate tangential cells, CH cells, show involvement in these responses. Imaging from a variety of direction-selective cells in the lobula plate shows no evidence of dynamics that match the behavior, suggesting that the observed inversion in turning direction emerges downstream of the lobula plate. Further, anti-directional turning declines with age and exposure to light. These results show that Drosophila optomotor turning behaviors contain rich, stimulus-dependent dynamics that are inconsistent with simple reflexive stabilization responses.

Neural mechanisms to incorporate visual counterevidence in self motion estimation.

In selecting appropriate behaviors, animals should weigh sensory evidence both for and against specific beliefs about the world. For instance, animals measure optic flow to estimate and control their own rotation. However, existing models of flow detection can confuse the movement of external objects with genuine self motion. Here, we show that stationary patterns on the retina, which constitute negative evidence against self rotation, are used by the fruit fly Drosophila to suppress inappropriate stabilizing rotational behavior. In silico experiments show that artificial neural networks optimized to distinguish self and world motion similarly detect stationarity and incorporate negative evidence. Employing neural measurements and genetic manipulations, we identified components of the circuitry for stationary pattern detection, which runs parallel to the fly's motion- and optic flow-detectors. Our results exemplify how the compact brain of the fly incorporates negative evidence to improve heading stability, exploiting geometrical constraints of the visual world.

CDKL5 deficiency causes epileptic seizures independent of cellular mosaicism.

OBJECTIVE: In a study using a mouse model of CDKL5 deficiency disorder (CDD), seizures are specific to female mice heterozygous for Cdkl5 mutations and not observed in hemizygous knockout males or homozygous knockout females. The aim of this study was to examine whether the clinical phenotype of patients with CDD can be impacted by the type of genetic variant. METHODS: Eleven CDD patients (six females and five males) were included in this study. The molecular diagnosis of hemizygous male patients was performed using digital PCR and their clinical phenotypes were compared with those of patients with mosaic or heterozygous CDKL5 variants. The severity of clinical phenotypes was graded by using CDKL5 Developmental Score and the adapted version of the CDKL5 Clinical Severity Assessment. The effect of cellular mosaicism on the severity of CDD was studied by comparing the clinical characteristics and comorbidities between individuals with hemizygous and mosaic or heterozygous CDKL5 variants. RESULTS: One of the five male patients was mosaic for the CDKL5 variant. All patients developed seizures irrespective of their genetic status of the pathogenic variant. However, cellular mosaicism of CDKL5 deficiency was associated with lesser severity of other comorbidities such as feeding, respiratory, and visual functional impairments. SIGNIFICANCE: This study provided evidence that cellular mosaicism of CDKL5 deficiency was not necessarily required for developing epilepsy. CDD patients not only exhibited clinical features of epilepsy but also exhibited the developmental consequences arising directly from the effect of the CDKL5 pathogenic variant.

Atomic force microscopy identifies the alteration of rheological properties of the cardiac fibroblasts in idiopathic restrictive cardiomyopathy.

Restrictive cardiomyopathy (RCM) is a rare disease characterized by increased ventricular stiffness and preserved ventricular contraction. Various sarcomere gene variants are known to cause RCM; however, more than a half of patients do not harbor such pathogenic variants. We recently demonstrated that cardiac fibroblasts (CFs) play important roles in inhibiting the diastolic function of cardiomyocytes via humoral factors and direct cell-cell contact regardless of sarcomere gene mutations. However, the mechanical properties of CFs that are crucial for intercellular communication and the cardiomyocyte microenvironment remain less understood. In this study, we evaluated the rheological properties of CFs derived from pediatric patients with RCM and healthy control CFs via atomic force microscopy. Then, we estimated the cellular modulus scale factor related to the cell stiffness, fluidity, and Newtonian viscosity of single cells based on the single power-law rheology model and analyzed the comprehensive gene expression profiles via RNA-sequencing. RCM-derived CFs showed significantly higher stiffness and viscosity and lower fluidity compared to healthy control CFs. Furthermore, RNA-sequencing revealed that the signaling pathways associated with cytoskeleton elements were affected in RCM CFs; specifically, cytoskeletal actin-associated genes (ACTN1, ACTA2, and PALLD) were highly expressed in RCM CFs, whereas several tubulin genes (TUBB3, TUBB, TUBA1C, and TUBA1B) were down-regulated. These results implies that the signaling pathways associated with cytoskeletal elements alter the rheological properties of RCM CFs, particularly those related to CF-cardiomyocyte interactions, thereby leading to diastolic cardiac dysfunction in RCM.

Wide Spectrum of Cardiac Phenotype in Myofibrillar Myopathy Associated With a Bcl-2-Associated Athanogene 3 Mutation: A Case Report and Literature Review.

ABSTRACT: Myofibrillar myopathy is a clinically and genetically heterogeneous group of muscle disorders characterized by myofibrillar degeneration. Bcl-2-associated athanogene 3 (BAG3)-related myopathy is the rarest form of myofibrillar myopathy. Patients with BAG3-related myopathy present with early-onset and progressive muscle weakness, rigid spine, respiratory insufficiency, and cardiomyopathy. Notably, the heterozygous mutation (Pro209Leu) in BAG3 is commonly associated with rapidly progressive cardiomyopathy in childhood. We describe a male patient with the BAG3 (Pro209Leu) mutation. The patient presented at age 7 years with muscle weakness predominantly in the proximal lower limbs. Histologic findings revealed a mixture of severe neurogenic and myogenic changes. His motor symptoms progressed rapidly in the next decade, becoming wheelchair-dependent by age 17 years; however, at the age of 19 years, cardiomyopathy was not evident. This study reports a case of BAG3-related myopathy without cardiac involvement and further confirmed the wide phenotypic spectrum of BAG3-related myopathy.

Structural and functional changes in the brains of patients with Rett syndrome: A multimodal MRI study.

OBJECTIVE: To clarify the relationship between structural and functional changes in the brains of patients with Rett syndrome (RTT) using multimodal magnetic resonance imaging (MRI). METHODS: Nine subjects with typical RTT (RTTs) and an equal number of healthy controls (HCs) underwent structural MRI, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI). The measurements obtained from each modality were statistically compared between RTTs and HCs and examined for their correlation with the clinical severity of RTTs. RESULTS: Structural MRI imaging revealed volume reductions in most cortical and subcortical regions of the brain. Remarkable volume reductions were observed in the frontal and parietal lobes, cerebellum, and subcortical regions including the putamen, hippocampus, and corpus callosum. DTI analysis revealed decreased white matter integrity in broad regions of the brain. Fractional anisotropy values were greatly decreased in the superior longitudinal fasciculus, corpus callosum, and middle cerebellar peduncle. Rs-fMRI analysis showed decreased functional connectivity in the interhemispheric dorsal attention network, and between the visual and cerebellar networks. The clinical severity of RTTs correlated with the volume reduction of the frontal lobe and cerebellum, and with changes in DTI indices in the fronto-occipital fasciculus, corpus callosum, and cerebellar peduncles. CONCLUSION: Regional volume and white matter integrity of RTT brains were reduced in broad areas, while most functional connections remained intact. Notably, two functional connectivities, between cerebral hemispheres and between the cerebrum and cerebellum, were decreased in RTT brains, which may reflect the structural changes in these brain regions.

Neural mechanisms to exploit positional geometry for collision avoidance.

Visual motion provides rich geometrical cues about the three-dimensional configuration of the world. However, how brains decode the spatial information carried by motion signals remains poorly understood. Here, we study a collision-avoidance behavior in Drosophila as a simple model of motion-based spatial vision. With simulations and psychophysics, we demonstrate that walking Drosophila exhibit a pattern of slowing to avoid collisions by exploiting the geometry of positional changes of objects on near-collision courses. This behavior requires the visual neuron LPLC1, whose tuning mirrors the behavior and whose activity drives slowing. LPLC1 pools inputs from object and motion detectors, and spatially biased inhibition tunes it to the geometry of collisions. Connectomic analyses identified circuitry downstream of LPLC1 that faithfully inherits its response properties. Overall, our results reveal how a small neural circuit solves a specific spatial vision task by combining distinct visual features to exploit universal geometrical constraints of the visual world.

Novel NARS2 variant causing leigh syndrome with normal lactate levels.

Leigh syndrome is the most genetically heterogenous phenotype of mitochondrial disease. We describe a patient with Leigh syndrome whose diagnosis had not been confirmed because of normal metabolic screening results at the initial presentation. Whole-exome sequencing identified pathogenic variants in NARS2, the gene encoding a mitochondrial asparaginyl-tRNA synthetase. One of the biallelic variants was novel. This highlights the essential role of genetic testing for a definite diagnosis of Leigh syndrome.

Usefulness of 3D CT/MRI Fusion Imaging for the Evaluation of Lumbar Disc Herniation and Kambin's Triangle.

Study design: Prospective study. Objective: The aim of this study is to visualize the morphology of a lumbar herniated disc and Kambin's triangle in three dimensions (3D) based on preoperative CT/MRI fusion images. Methods: CT/MRI fusion images of 23 patients (10 males and 13 females; mean age 58.2 years) were used to evaluate Kambin's triangle, which is created between the superior articular process (SAP), exiting nerve root (ENR), inferiorly by the superior endplate of the lower lumbar vertebra and dural canal medially at 60 degree and 45 degree endoscopic approach angles. The percentage of the safe usage of transforaminal endoscopic approach was evaluated to utilize a 5 mm dilater without partial facet resection in the fusion image. The 3D lumbar nerve root sleeve angulation (3DNRA), which is the angle between the axis of the thecal sac and the nerve root sleeve, was calculated. The herniated discs were also visualized in the CT/MRI fusion image. Results: The 3DNRA became smaller from L2 to S1. The L2 3DNRA was statistically larger than those of the other root, and the S1 3DNRA was significantly smaller than the others (p < 0.05). (L2, 41.0°; L3, 35.6°; L4, 36.4°; L5, 33.9°; and S1, 23.2°). The SAP-ENR distance at 60° was greatest at L4/5 (5.9 mm). Possible needle passages at 60° to each disc level were 89.1% at L2/3, 87.0% at L3/4 and 84.8% at L4/5. However, the safe 5 mm dilater passage at 60° without bony resection to each disc level were 8.7% at L2/3, 28.3% at L3/4 and 37.0% at L4/5. The 60° corridor at L2/3 was the narrowest (p < 0.01). All herniated discs were visualized in the fusion image and the root compression site was clearly demonstrated especially with foraminal/extraforaminal herniations. Conclusion: The 3D lumbar CT/MRI fusion image enabled a combined nerve-bony assessment of Kambin's triangle and herniated disc. A fully endoscopic 5 mm dilater may retract the exiting nerve root in more than 60% of total cases. This new imaging technique could prove to be very useful for the safety of endoscopic lumbar disc surgery.

Vascular Endothelial Dysfunction in the Thoracic Aorta of Rats with Ischemic Acute Kidney Injury: Contribution of Indoxyl Sulfate.

Chronic kidney disease (CKD) and cardiovascular disease are known to be linked, and the involvement of indoxyl sulfate (IS), a type of uremic toxin, has been suggested as one of the causes. It is known that IS induces vascular dysfunction through overproduction of reactive oxygen species (ROS). On the other hand, the involvement of IS in the vascular dysfunction associated with acute kidney injury (AKI) is not fully understood. Therefore, we investigated this issue using the thoracic aorta of rats with ischemic AKI. Ischemic AKI was induced by occlusion of the left renal artery and vein for 45 min, followed by reperfusion 2 weeks after contralateral nephrectomy. One day after reperfusion, there was marked deterioration in renal function evidenced by an increase in plasma creatinine. Furthermore, blood IS levels increased markedly due to worsening renal function. Seven days and 28 days after reperfusion, blood IS levels decreased with the improvement in renal function. Of note, acetylcholine-induced vasorelaxation deteriorated over time after reperfusion, contradicting the recovery of renal function. In addition, 28 days after reperfusion, we observed a significant increase in ROS production in the vascular tissue. Next, we administered AST-120, a spherical adsorbent charcoal, after reperfusion to assess whether the vascular endothelial dysfunction associated with the ischemic AKI was due to a temporary increase in blood IS levels. AST-120 reduced the temporary increase in blood IS levels after reperfusion without influencing renal function, but did not restore the impaired vascular reactivity. Thus, in ischemic AKI, we confirmed that the vascular endothelial function of the thoracic aorta is impaired even after the recovery of kidney injury, probably with excessive ROS production. IS, which increases from ischemia to early after reperfusion, may not be a major contributor to the vascular dysfunction associated with ischemic AKI.

Pharmacological Alteration of Cellular Mechanical Properties in Pulmonary Arterial Smooth Muscle Cells of Idiopathic Pulmonary Arterial Hypertension.

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a progressive disease caused by vascular remodeling of the pulmonary arteries with elevated pulmonary vascular resistance. Recently, various pulmonary vasodilator drugs have become available in the clinical field, and have dramatically ameliorated the prognosis of IPAH. However, little is known about how the mechanical properties of pulmonary arterial smooth muscle cells (PASMCs) are altered under drug supplementation. METHODS: Atomic force microscopy (AFM) was used to investigate the mechanical properties of PASMCs derived from a patient with IPAH (PAH-PASMCs) and a healthy control (N-PASMCs) which received the supplementation of clinically used drugs for IPAH: sildenafil, macitentan, and riociguat. RESULTS: PASMCs derived from PAH-PASMCs were stiffer than those derived from N-PASMCs. With sildenafil treatment, the apparent Young's modulus (E 0) of cells significantly decreased in PAH-PASMCs but remained unchanged in N-PASMCs. The decrease in E 0 of PAH-PASMCs was also observed in macitentan and riociguat treatment. The stress relaxation AFM revealed that the decrease in E 0 of PAH-PASMCs resulted from a decrease in the cell elastic modulus and/or increase in cell fluidity. The combination treatment of macitentan and riociguat showed an additive effect on cell mechanical properties, implying that this clinically accepted combination therapy for IPAH influences the intracellular mechanical components. CONCLUSIONS: Pulmonary vasodilator drugs affect the mechanical properties of PAH-PASMCs, and there exists a mechanical effect of combination treatment on PAH-PASMCs.

Phenotypic overlap between pyruvate dehydrogenase complex deficiency and FOXG1 syndrome.

Pyruvate dehydrogenase complex (PDHC) deficiency is a mitochondrial disorder. We report two cases of PDHC deficiency with clinical symptoms and brain imaging findings reminiscent of FOXG1 syndrome, suggesting a phenotypic overlap of these disorders.

Early diagnosis of MECP2 duplication syndrome: Insights from a nationwide survey in Japan.

This study aimed to elucidate the clinical characteristics of MECP2 duplication syndrome (MDS), particularly at initial presentation, and to provide clinical clues for the early diagnosis of this condition. We conducted a nationwide survey for MDS by sending questionnaires to 575 hospitals where board-certified pediatric neurologists were working and 195 residential hospitals for persons with severe motor and intellectual disabilities in Japan. This survey found 65 cases of MDS, and clinical data of 24 cases in which the diagnosis was genetically confirmed were analyzed. More than half of the patients (52%) had visited a hospital at least once during infancy due to symptoms associated with MDS, with a median age at the initial visit of 7 months. The symptoms that were frequently prevalent at the first visit were facial dysmorphic features, hypotonia, motor developmental delay, and recurrent infections. Dysmorphic features included small mouth, tented upper lip, tapered fingers, and hypertelorism. Other symptoms, including epilepsy, intellectual disabilities, autistic features, stereotypic movements, and gastrointestinal problems, generally appeared later with age. Some symptoms of MDS were found to be age-dependent and may not be noticeable in infancy. Recognition of these clinical characteristics may facilitate the early diagnosis and proper treatment of patients with MDS, improve their long-term outcomes, and help adapt appropriate genetic counseling.

A Complex Phenotype of a Patient with Spastic Paraplegia Type 4 Caused by a Novel Pathogenic Variant in the SPAST Gene.

Hereditary spastic paraplegias (HSPs) are rare neurological disorders caused by degeneration of the corticospinal tract. Among the 79 causative genes involved in HSPs, variants in SPAST on chromosome 2p22, which encodes the microtubule-severing protein spastin, are responsible for spastic paraplegia type 4 (SPG4), the most common form of HSPs. SPG4 is characterized by a clinically pure phenotype that is associated with restricted involvement of the corticospinal tract; however, it is often accompanied by additional neurological symptoms such as epilepsy and cognitive impairment. There are few reports regarding the clinical course and treatment of epilepsy associated with SPG4. We describe a 21-year-old male patient with progressive weakness and spasticity of the lower limbs since infancy, which was complicated by epilepsy and cognitive impairment. Magnetic resonance imaging of the brain showed right hippocampal atrophy before the onset of epilepsy. Genetic analysis revealed a novel missense variant (NM_014946.4:c.1330G>C, p.Asp444His) in the SPAST gene. At the age of 13, the patient developed focal epilepsy, characterized by focal onset seizures that were preceded by a sensation of chest tightness. Carbamazepine, levetiracetam, and zonisamide were ineffective in controlling the seizures; however, the use of lacosamide in combination with lamotrigine and valproate was highly effective in improving the seizure symptoms and led to the patient being seizure free for at least 2 years. In conclusion, the missense variant in SPAST may cause a complex SPG4 phenotype accompanied by epilepsy and cognitive impairment, suggesting that the clinical manifestations of this condition do not confine to the motor system.