Upper motor neuron signs in primary lateral sclerosis and hereditary spastic paraplegia.

INTRODUCTION/AIMS: The frequency and distribution of upper motor neuron (UMN) signs in primary lateral sclerosis (PLS) are unknown. We aimed to study the spectrum of UMN signs in PLS and compare it with hereditary spastic paraplegia (HSP). METHODS: We retrospectively analyzed the frequency of different UMN signs, including hyperreflexia (limbs and jaw), limb and tongue spasticity, Babinski, and Hoffman signs, in PLS patients at first observation and compared this respect to onset region and symptom duration. We also compared PLS versus HSP patients. RESULTS: We included 34 PLS and 20 HSP patients, with a median symptom duration at first visit of 3.0 (interquartile range, IQR = 4.0) and 19.0 (IQR = 22.0) years, respectively. In PLS patients, hyperreflexia of upper (UL) (88.2%) and lower (LL) (91.2%) limbs, and LL spasticity (79.4%) were the most common findings. Spasticity of LL was significantly (p = .012) more frequent in LL-spinal onset subgroup, tongue spasticity in bulbar-onset subgroup (p = .021), and Hoffman sign in UL-spinal onset subgroup (p = .024). The PLS subgroup with shorter disease duration had a higher frequency of abnormal jaw jerk reflex (p = .037). Compared with HSP, PLS patients had a higher frequency of UL hyperreflexia (88.2% vs. 42.1%, p < .001) and UL spasticity (44.1% vs. 0.0%, p < .001). Asymmetric distribution of UMN signs was present in PLS and not in HSP. DISCUSSION: In PLS, UL UMN signs are nearly always present and UMN sign distribution appears to be associated with onset region. At first observation, bulbar involvement, asymmetrical distribution of UMN signs and UL spasticity may indicate PLS versus HSP.

Clinical and neuroimaging characteristics of primary lateral sclerosis with overlapping features of progressive supranuclear palsy.

BACKGROUND AND PURPOSE: Primary lateral sclerosis (PLS) is a neurodegenerative disorder that primarily affects the central motor system. In rare cases, clinical features of PLS may overlap with those of progressive supranuclear palsy (PSP). We investigate neuroimaging features that can help distinguish PLS with overlapping features of PSP (PLS-PSP) from PSP. METHODS: Six patients with PLS-PSP were enrolled between 2019 and 2023. We compared their clinical and neuroimaging characteristics with 18 PSP-Richardson syndrome (PSP-RS) patients and 20 healthy controls. Magnetic resonance imaging, 18F-flortaucipir positron emission tomography (PET), quantitative susceptibility mapping, and diffusion tensor imaging tractography (DTI) were performed to evaluate eight brain regions of interest. Area under the receiver operating characteristic curve (AUROC) was calculated. RESULTS: Five of the six PLS-PSP patients (83.3%) were male. Median age at symptom onset was 61.5 (52.5-63) years, and all had mixed features of PLS and PSP. Volumes of the pallidum, caudate, midbrain, and cerebellar dentate were smaller in PSP-RS than PLS-PSP, providing good discrimination (AUROC = 0.75 for all). The susceptibilities in pallidum, midbrain, and cerebellar dentate were greater in PSP-RS compared to PLS-PSP, providing excellent discrimination (AUROC ≥ 0.90 for all). On DTI, fractional anisotropy (FA) in the posterior limb of the internal capsule from the corticospinal tract was lower in PLS-PSP compared to PSP-RS (AUROC = 0.86), but FA in the superior cerebellar peduncle was lower in PSP-RS (AUROC = 0.95). Pallidum flortaucipir PET uptake was greater in PSP-RS compared to PLS-PSP (AUROC = 0.74). CONCLUSIONS: Regional brain volume, tractography, and magnetic susceptibility, but not tau-PET, are useful in distinguishing PLS-PSP from PSP.

Reliability and consistency of the Japanese version of the Primary Lateral Sclerosis Functional Rating Scale.

BACKGROUND: Primary lateral sclerosis (PLS) is an extremely rare condition; therefore, to date no clinical studies have been conducted. The Primary Lateral Sclerosis Functional Rating Scale (PLSFRS) was developed in the United States of America. The PLSFRS is a crucial assessment scale for international collaborative research and future clinical trials for PLS. It is useful for evaluating medical conditions through face-to-face assessments and telephone interviews such as when a face-to-face assessment is not possible due to disasters or the burden of hospital visits. This study assessed the reliability and consistency of in-person and telephone interviews using the Japanese version of the PLSFRS. METHODS: We enrolled 19 Japanese patients who met the specific criteria for inclusion at the six collaborating institutions. The PLSFRS assessments were performed by two evaluators at defined time points and analyzed for intra-rater and inter-rater reliability and consistency between the in-person and telephone interviews. RESULTS: The Japanese version of the PLSFRS was developed by a specialized company and translator, and modified to consider the Japanese lifestyle through a consensus among motor neuron specialists. The quadratic-weighted kappa coefficients for the intra-rater and the inter-rater agreement were substantial (intra-rater: 0.691-1.000, inter-rater: 0.634-1.000). Moreover, the intraclass correlation coefficient for the PLSFRS total score was 0.997 (95% confidence interval, 0.992-0.999). CONCLUSIONS: This study provides results regarding the Japanese version of the PLSFRS intra-rater and inter-rater reliability and consistency between in-person and telephone interviews.

Cortico-muscular coherence in primary lateral sclerosis reveals abnormal cortical engagement during motor function beyond primary motor areas.

Primary lateral sclerosis (PLS) is a slowly progressing disorder, which is characterized primarily by the degeneration of upper motor neurons (UMNs) in the primary motor area (M1). It is not yet clear how the function of sensorimotor networks beyond M1 are affected by PLS. The aim of this study was to use cortico-muscular coherence (CMC) to characterize the oscillatory drives between cortical regions and muscles during a motor task in PLS and to examine the relationship between CMC and the level of clinical impairment. We recorded EEG and EMG from hand muscles in 16 participants with PLS and 18 controls during a pincer-grip task. In PLS, higher CMC was observed over contralateral-M1 (α- and γ-band) and ipsilateral-M1 (ß-band) compared with controls. Significant correlations between clinically assessed UMN scores and CMC measures showed that higher clinical impairment was associated with lower CMC over contralateral-M1/frontal areas, higher CMC over parietal area, and both higher and lower CMC (in different bands) over ipsilateral-M1. The results suggest an atypical engagement of both contralateral and ipsilateral M1 during motor activity in PLS, indicating the presence of pathogenic and/or adaptive/compensatory alterations in neural activity. The findings demonstrate the potential of CMC for identifying dysfunction within the sensorimotor networks in PLS.

A case of Mills' syndrome: initially characterized by one cerebral hemisphere atrophy and decreased brain metabolism then evolving into amyotrophic lateral sclerosis.

This article reports a case of Mills' syndrome that initially manifested as atrophy of one cerebral hemisphere and decreased brain metabolism, which developed into amyotrophic lateral sclerosis in the fourth year of the disease. Mills' syndrome is a rare type of motor neuron disease, with only over 20 cases reported since 1990, but most lack imaging such as PET and DTI. This article provides a complete report of the 18F-FDG-PET and DTI images consistent with the characteristics of Mills' syndrome. In addition, we have discovered some new phenomena, which have certain clinical and teaching values. Firstly, the frontal, parietal and temporal lobes on the side of the lesion in the pyramidal tract of this patient were significantly atrophic, indicating that unilateral brain lobe atrophy may be a new feature of Mills' syndrome. Secondly, although there were no abnormalities in three EMG tests taken during the 4 years prior to the onset of the disease, amyotrophy and ALS-like EMG features appeared in the fourth year, suggesting that some Mills' syndrome may progress more rapidly to ALS. This highlights the importance of regular follow-up electromyography in Mills' syndrome patients.

An autopsy case of progressive supranuclear palsy with severe corticospinal tract degeneration.

We report an autopsy case of a 70-year-old man who was clinically diagnosed with atypical progressive supranuclear palsy (PSP). He initially presented with gait ataxia and then showed vertical gaze palsy, rigidity, akinesia, dysphagia, and mild cognitive impairment, followed by prominent upper motor signs later in the course of the disease. Cranial magnetic resonance imaging revealed tegmental atrophy of the midbrain. Autopsy revealed severe neuronal loss and gliosis in the motor cortex and corticospinal degeneration and mild to moderate neuronal loss and gliosis in the basal ganglia, substantia nigra, midbrain, and pons. Tufted astrocytes were primarily found in the motor cortex and basal ganglia. Globose-type neurofibrillary tangles were observed in the locus coeruleus and nucleus olivaris inferior. In the cerebellar cortex, mild Purkinje cell loss and scattered axonal torpedoes were observed with tau-positive Purkinje cells. The dentate nucleus displayed severe neuronal loss and gliosis. The present case showed characteristics of both PSP with prominent cerebellar ataxia (PSP-C) and PSP-primary lateral sclerosis (PSP-PLS).

Harnessing Big Data in Amyotrophic Lateral Sclerosis: Machine Learning Applications for Clinical Practice and Pharmaceutical Trials.

The arrival of genotype-specific therapies in amyotrophic lateral sclerosis (ALS) signals the dawn of precision medicine in motor neuron diseases (MNDs). After decades of academic studies in ALS, we are now witnessing tangible clinical advances. An ever increasing number of well-designed descriptive studies have been published in recent years, characterizing typical disease-burden patterns in vivo and post mortem. Phenotype- and genotype-associated traits and "typical" propagation patterns have been described based on longitudinal clinical and biomarker data. The practical caveat of these studies is that they report "group-level", stereotyped trajectories representative of ALS as a whole. In the clinical setting, however, "group-level" biomarker signatures have limited practical relevance and what matters is the meaningful interpretation of data from a single individual. The increasing availability of large normative data sets, national registries, extant academic data, consortium repositories, and emerging data platforms now permit the meaningful interpretation of individual biomarker profiles and allow the categorization of single patients into relevant diagnostic, phenotypic, and prognostic categories. A variety of machine learning (ML) strategies have been recently explored in MND to demonstrate the feasibility of interpreting data from a single patient. Despite the considerable clinical prospects of classification models, a number of pragmatic challenges need to be overcome to unleash the full potential of ML in ALS. Cohort size limitations, administrative hurdles, data harmonization challenges, regulatory differences, methodological obstacles, and financial implications and are just some of the barriers to readily implement ML in routine clinical practice. Despite these challenges, machine-learning strategies are likely to be firmly integrated in clinical decision-making and pharmacological trials in the near future.

Primary lateral sclerosis associated with PSEN1 Pro284Leu variant in a Colombian family: Clinical and neuropathological features.

INTRODUCTION: This study investigates primary lateral sclerosis (PLS) as a rare manifestation of the presenilin 1 (PSEN1) NM_000021 c.851C > T p.Pro284Leu variant in three siblings of a Colombian family, outlining its clinical and neuropathological features and their relationship to Alzheimer's disease (AD). METHODS: Data were gathered using clinical evaluations, next-generation genetic sequencing, magnetic resonance imaging, biomarker analysis, and neuropathological examination. RESULTS: Carriers of the PSEN1 Pro284Leu variant exhibited classic PLS symptoms, including unilateral onset and bulbar syndromes, along with cognitive decline. Neuropathology showed corticospinal tract degeneration without amyloid beta deposition in spinal white matter. DISCUSSION: Our findings suggest an overlap between PLS and AD pathology in PSEN1 variant carriers. Results support considering PLS when diagnosing AD-related motor syndromes and including PSEN1 evaluation when performing genetic testing for PLS. The study highlights the need for further research to clarify the PLS-AD relationship, informing future treatments and clinical trials. HIGHLIGHTS: Pathogenic variants in presenilin 1 (PSEN1) can manifest as hereditary primary lateral sclerosis PSEN1 Pro284Leu carriers present motor, cognitive, and behavioral alterations  Cases had corticospinal tract microgliosis and severe Aß pathology in motor cortex  There was no evidence of amyloid deposition in the spinal cord white matter  All the neuropathology images are available for online visualization  Myelin pallor in the spinal cord is confined to the lateral corticospinal tracts.

Could PLS represent a UMN-predominant ALS syndrome?

Primary lateral sclerosis (PLS) is a motor neuron condition marked by pure upper motor neuron (UMN) degeneration. PLS represents around 3% of all motor neuron diseases. Classically the prognosis of PLS is less severe than those of amyotrophic lateral sclerosis (ALS). This explains the necessity to distinguish both conditions as early as possible. The key hallmark between the two diseases is the involvement of the lower motor neuron (LMN) system which is classically considered spared in PLS contrary to ALS. Although it seemed clinically easy to distinguish PLS from ALS with the aid of clinical and complementary examinations, there is a large body of evidence highlighting that the LMN system might be impaired in PLS. This led us to suggest that PLS might be considered as an almost pure UMN ALS phenotype.

Utilizing machine learning and lipidomics to distinguish primary lateral sclerosis from amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: There are currently no imaging or blood diagnostic biomarkers that can differentiate amyotrophic lateral sclerosis (ALS) from primary lateral sclerosis (PLS) patients early in their disease courses. Our objective is to examine whether patients with PLS can be differentiated from ALS reliably by using plasma lipidome profile and supervised machine learning. METHODS: 40 ALS and 28 PLS patients derived from the Multicenter Cohort study of Oxidative Stress (COSMOS) and 28 healthy control volunteers (CTR) were included. ALS, PLS, and CTR were matched by age and sex. Plasma samples were obtained after overnight fasting. Lipids were extracted from the plasma samples and analyzed using liquid chromatography/mass spectrometry to obtain relative concentrations of 392 lipid species. The lipid data were partitioned into training and testing datasets randomly. An elastic net algorithm was trained using cross-validation to classify PLS vs ALS and PLS vs CTR. Final accuracy was evaluated in the testing dataset. RESULTS: The elastic net model trained with labeled PLS and ALS training lipid dataset demonstrated accuracy (number classified correctly/total number), sensitivity, and specificity of 100% in classifying PLS vs ALS in the unlabeled testing lipid dataset. Similarly, the elastic net model trained with labeled PLS and CTR training lipid datasets demonstrated accuracy, sensitivity, and specificity of 88% in classifying PLS vs CTR in the unlabeled testing lipid dataset. DISCUSSION: Our study suggests PLS patients can be accurately distinguished from ALS and CTR by combining lipidome profile and supervised machine learning without clinical information.

Not a benign motor neuron disease: longitudinal imaging captures relentless motor connectome disintegration in primary lateral sclerosis.

BACKGROUND AND PURPOSE: Primary lateral sclerosis (PLS) is a progressive upper motor neuron disorder associated with considerable clinical disability. Symptoms are typically exclusively linked to primary motor cortex degeneration and the contribution of pre-motor, supplementary motor, cortico-medullary and inter-hemispheric connectivity alterations are less well characterized. METHODS: In a single-centre, prospective, longitudinal neuroimaging study 41 patients with PLS were investigated. Patients underwent standardized neuroimaging, genetic profiling with whole exome sequencing, and comprehensive clinical assessments including upper motor neuron scores, tapping rates, mirror movements, spasticity assessment, cognitive screening and evaluation for pseudobulbar affect. Longitudinal neuroimaging data from 108 healthy controls were used for image interpretation. A standardized imaging protocol was implemented including 3D T1-weighted structural, diffusion tensor imaging and resting-state functional magnetic resonance imaging. Following somatotopic segmentation, cortical thickness analyses, probabilistic tractography, blood oxygenation level dependent signal analyses and brainstem volumetry were conducted to evaluate cortical, brainstem, cortico-medullary and inter-hemispheric connectivity alterations both cross-sectionally and longitudinally. RESULTS: Our data confirm progressive primary motor cortex degeneration, considerable supplementary motor and pre-motor area involvement, progressive brainstem atrophy, cortico-medullary and inter-hemispheric disconnection, and close associations between clinical upper motor neuron scores and somatotopic connectivity indices in PLS. DISCUSSION: Primary lateral sclerosis is associated with relentlessly progressive motor connectome degeneration. Clinical disability in PLS is likely to stem from a combination of intra- and inter-hemispheric connectivity decline and primary, pre- and supplementary motor cortex degeneration. Simple 'bedside' clinical tools, such as tapping rates, are excellent proxies of the integrity of the relevant fibres of the contralateral corticospinal tract.

Primary lateral sclerosis plus parkinsonism: a case report.

BACKGROUND: The standard of diagnosing primary lateral sclerosis, the Pringle criteria, requires three years of purely upper motor neuron symptom presentation before confirming diagnosis. This classic standard has been questioned on occasion due to its restrictive range of both time period and symptomatic exhibition. CASE PRESENTATION: This case report will review a 57-year-old Caucasian female who presented with pyramidal and extrapyramidal features suggestive of the exceedingly rare disease primary lateral sclerosis plus parkinsonism. We will describe the mixture of upper motor neuron signs and striking parkinsonian symptoms experienced by the patient, as well as the full diagnostic workup leading to her preliminary diagnosis. The details of this case will then be utilized to explore the diagnostic criteria of primary lateral sclerosis, as well as to work through the differential of conditions resembling Parkinson's disease. CONCLUSIONS: The current criteria to diagnose primary lateral sclerosis may be excluding patients with the disease and is an ongoing area of investigation. A thorough differential including other neurodegenerative conditions is necessary to consider and requires long-term follow-up.

Motor Band Sign in Motor Neuron Disease: A Marker for Upper Motor Neuron Involvement.

BACKGROUND AND OBJECTIVE: The prevalence and role of the motor band sign (MBS) remain unclear in motor neuron disease. We report the frequency of MBS in amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS), its correlation with clinical upper motor neuron (UMN) signs, and prognostic value in ALS. METHODS: We conducted a retrospective study of ALS, PLS, and controls with retrievable MRI between 2010 and 2018. We compared the frequencies of MBS across the three groups, and studied correlation between susceptibility-weighted MRI measurements in primary motor cortices and contralateral UMN features. Clinical outcomes were compared between ALS with and without MBS. RESULTS: Thirteen ALS, 5 PLS, and 10 controls were included (median age 60 years, IQR 54-66 years; 14/28 males). MBS was present in 9/13 (69.2%, 95% CI 38.9-89.6%) and 4/5 (80.0%, 95% CI 29.9-99.0%) of ALS and PLS, respectively, and none in controls. 2/13 (15.4%, 95% CI 2.7-46.3%) ALS and 3/5 (60.0%, 95% CI 17.0-92.7%) PLS had MBS in the absence of corticospinal T2/FLAIR hyperintensity sign. Susceptibility measurements in left motor cortices had a significantly positive correlation with contralateral UMN signs in ALS (τb = 0.628, p = 0.03). Similar but nonsignificant trends was observed for right motor cortices in ALS (τb = 0.516, p = 0.07). There were no significant differences in mRS at last follow-up, mortality, or time from symptom onset to last follow-up between ALS patients with and without MBS. CONCLUSIONS: We provide limited evidence that MBS and susceptibility quantification measurements in motor cortices may serve as surrogate markers of UMN involvement in motor neuron disease.

An autopsy case of diffuse atypical argyrophilic grain disease (AGD) with presenile onset and three-year course of motor and cognitive impairment.

We report a case of argyrophilic grain disease (AGD) with unique clinical and pathological presentations. A 52-year-old man presented with spastic quadriparesis, bulbar palsy, and mild cognitive decline. His condition deteriorated rapidly and he died of pneumonia three years from onset. Pathologically, neuronal degeneration was involved severely in the amygdala, ambient gyrus, midbrain tegmentum, and reticular formation. The neurons of the temporal lobe, cingulate gyrus, brainstem, and spinal gray matter were also lost moderately. There was diffuse 4-repeat tau-pathology with argyrophilic grains. There were pretangles, globose-type neurofibrillary tangles, and coiled bodies in the cerebral cortices, basal ganglia, thalami, brainstem, and the spinal cord except for the cerebellar cortices. There was no pathologic mutation in MAPT.

Iron-sensitive MR imaging of the primary motor cortex to differentiate hereditary spastic paraplegia from other motor neuron diseases.

OBJECTIVES: Hereditary spastic paraplegia (HSP) is a group of genetic neurodegenerative diseases characterised by upper motor neuron (UMN) impairment of the lower limbs. The differential diagnosis with primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS) can be challenging. As microglial iron accumulation was reported in the primary motor cortex (PMC) of ALS cases, here we assessed the radiological appearance of the PMC in a cohort of HSP patients using iron-sensitive MR imaging and compared the PMC findings among HSP, PLS, and ALS patients. METHODS: We included 3-T MRI scans of 23 HSP patients, 7 PLS patients with lower limb onset, 8 ALS patients with lower limb and prevalent UMN onset (UMN-ALS), and 84 ALS patients with any other clinical picture. The PMC was visually rated on 3D T2*-weighted images as having normal signal intensity, mild hypointensity, or marked hypointensity, and differences in the frequency distribution of signal intensity among the diseases were investigated. RESULTS: The marked hypointensity in the PMC was visible in 3/22 HSP patients (14%), 7/7 PLS patients (100%), 6/8 UMN-ALS patients (75%), and 35/84 ALS patients (42%). The frequency distribution of normal signal intensity, mild hypointensity, and marked hypointensity in HSP patients was different than that in PLS, UMN-ALS, and ALS patients (p < 0.01 in all cases). CONCLUSIONS: Iron-sensitive imaging of the PMC could provide useful information in the diagnostic work - up of adult patients with a lower limb onset UMN syndrome, as the cortical hypointensity often seen in PLS and ALS cases is apparently rare in HSP patients. KEY POINTS: • The T2* signal intensity of the primary motor cortex was investigated in patients with HSP, PLS with lower limb onset, and ALS with lower limb and prevalent UMN onset (UMN-ALS) using a clinical 3-T MRI sequence. • Most HSP patients had normal signal intensity in the primary motor cortex (86%); on the contrary, all the PLS and the majority of UMN-ALS patients (75%) had marked cortical hypointensity. • The T2*-weighted imaging of the primary motor cortex could provide useful information in the differential diagnosis of sporadic adult-onset UMN syndromes.

Editorial Comment: Iron-sensitive MR imaging of the primary motor cortex to differentiate hereditary spastic paraplegia from other motor neuron diseases.

KEY POINTS: • Conventional and advanced MR techniques may aid in the diagnosis of motor neuron disease.• Iron-sensitive MR imaging of the primary motor cortex may reveal changes to help differentiate hereditary spastic paraplegia (HSP) from UMM predominant amyotrophic lateral sclerosis (UMN-ALS) and primary lateral sclerosis (PLS).• Additional research in this area is necessary.

Progressive motor neuron syndromes with single CNS lesions and CSF oligoclonal bands: never forget solitary sclerosis!

We describe 3 cases of solitary sclerosis (SS), a rare condition characterized by a single inflammatory demyelinating lesion in the white matter of the brain or spinal cord. All patients had progressive limb motor impairment (patient 1, 66-year-old female: left spastic hemiparesis; patient 2, 39-year-old male: right spastic hemiparesis; patient 3, 42-year-old female: proximally predominant left upper limb weakness with amyotrophy and fasciculations). In all patients, MRI disclosed a single small T2-hyperintense demyelinating lesion: in the right anterior paramedian upper medulla, in the median-left paramedian anterior lower medulla, and in the left paramedian anterior cervical spinal cord at C4 level, respectively. In patients 1 and 2, transcranial magnetic stimulation (TMS) demonstrated altered motor evoked potentials (MEPs) and increased central motor conduction time (CMCT) in the affected limbs; in patient 3, needle EMG revealed chronic neurogenic changes in C5-C7 muscles of left upper limb. Patients 1 and 2 had normal brain 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). CSF analysis demonstrated IgG oligoclonal bands in all patients. In patients 2 and 3, levels of neurofilament light chain (NFL) in CSF and serum, respectively, were within normal limits. The three cases were consistent with the diagnosis of SS. Notably, while the first two cases mimicked Mills' syndrome (the hemiparetic variant of primary lateral sclerosis, PLS), the third one was rather reminiscent of amyotrophic lateral sclerosis (ALS). This suggests including SS in the differential diagnosis not only of PLS, but also of ALS. We also report the first quantification of NFL levels in SS.

A case of vertebral artery compression syndrome mimicking primary lateral sclerosis.

PURPOSE: Vertebral artery compression syndrome (VACS) is an under-recognised condition that may be misdiagnosed as motor neuron disease. We report a case presenting features initially suggestive of primary lateral sclerosis (PLS) but later found to be VACS. CASE PRESENTATION: A 65-year-old man with hypertension was referred to our neurology department in the suspect of PLS. He presented with a 10-year history of involuntary jerk of the left lower limb, which ascended to the left upper limb 9 years later. He also developed intermittent painful spasms with a tendency to drag his left leg. His symptoms fluctuated with blood pressure. Neurological examination revealed upper motor neuron signs without lower motor neuron or sensory involvement. Electrophysiology studies were unremarkable. Brain MRI disclosed the left side of medulla oblongata was compressed by the tortuous left vertebral artery. Diffusion tensor tractography confirmed the corresponding corticospinal tract disruption. He was diagnosed with VACS and treated with antispasmodic medications and antihypertensive drugs. CONCLUSIONS: VACS should be considered into the differential diagnoses of PLS. A thorough clinical assessment and careful interpretation of brain MRI with advanced diffusion neuroimages can help confirm the diagnosis.

Primary Lateral Sclerosis: Clinical, radiological and molecular features.

Primary Lateral Sclerosis (PLS) is an uncommon motor neuron disorder. Despite the well-recognisable constellation of clinical manifestations, the initial diagnosis can be challenging and therapeutic options are currently limited. There have been no recent clinical trials of disease-modifying therapies dedicated to this patient cohort and awareness of recent research developments is limited. The recent consensus diagnostic criteria introduced the category 'probable' PLS which is likely to curtail the diagnostic journey of patients. Extra-motor clinical manifestations are increasingly recognised, challenging the view of PLS as a 'pure' upper motor neuron condition. The post mortem literature of PLS has been expanded by seminal TDP-43 reports and recent PLS studies increasingly avail of meticulous genetic profiling. Research in PLS has gained unprecedented momentum in recent years generating novel academic insights, which may have important clinical ramifications.

Familial clustering of primary lateral sclerosis and amyotrophic lateral sclerosis: Supplementary evidence for a continuum.

BACKGROUND AND PURPOSE: Primary lateral sclerosis (PLS) is a motor neuron disorder characterized by a pure upper motor neuron degeneration in the bulbar and spinal regions. The key difference with amyotrophic lateral sclerosis (ALS) is the lower motor neuron system integrity. Despite important literature on this disease, the pathophysiology of PLS remains unknown, and the link with ALS still balances between a continuum and a separate entity from ALS. METHODS: We report nine families in which both PLS and ALS cases occurred, in general among first-degree relatives. RESULTS: The patients with PLS and ALS had a typical disease presentation. Genetic studies revealed mutations in SQSMT1, TBK1, and TREM2 genes in two PLS patients and one ALS patient. CONCLUSIONS: These results strongly support a phenotypic continuum between PLS and ALS.