Ganglioside-induced differentiation associated protein 1 is a regulator of the mitochondrial network: new implications for Charcot-Marie-Tooth disease

Mutations in GDAP1 lead to severe forms of the peripheral motor and sensory neuropathy, Charcot-Marie-Tooth disease (CMT), which is characterized by heterogeneous phenotypes, including pronounced axonal damage and demyelination. We show that neurons and Schwann cells express ganglioside-induced differentiation associated protein 1 (GDAP1), which suggest that both cell types may contribute to the mixed features of the disease. GDAP1 is located in the mitochondrial outer membrane and regulates the mitochondrial network. Overexpression of GDAP1 induces fragmentation of mitochondria without inducing apoptosis, affecting overall mitochondrial activity, or interfering with mitochondrial fusion. The mitochondrial fusion proteins, mitofusin 1 and 2 and Drp1(K38A), can counterbalance the GDAP1-dependent fission. GDAP1-specific knockdown by RNA interference results in a tubular mitochondrial morphology. GDAP1 truncations that are found in patients who have CMT are not targeted to mitochondria and have lost mitochondrial fragmentation activity. The latter activity also is reduced strongly for disease-associated GDAP1 point mutations. Our data indicate that an exquisitely tight control of mitochondrial dynamics, regulated by GDAP1, is crucial for the proper function of myelinated peripheral nerves

Quality of life and upper limb disability in Charcot-Marie-Tooth disease: A pilot study

Charcot-Marie-Tooth (CMT) patients present mainly lower limbs disability, with slowly progressive distal muscle weakness and atrophy, but hands impairment is a relevant problem affecting the quality of life (QoL). The evaluation of the upper limb is of primary importance. Often these patients present subclinical disorders or report difficulties in manipulating objects, with little evidence in the most used outcome measures. We aim to investigate the impact of hand impairment in the perceived QoL of CMT persons and secondly whether the Disability of Arm, Shoulder and Hand (DASH) scale can be useful in assessing upper limb abilities in CMT. We recruited 23 patients with confirmed genetic diagnosis of CMT. We performed a clinical evaluation with Sollerman Hand Function Test (SHFT), Thumb Opposition Test (TOT) and CMT examination score (CMTES). We completed the clinical assessment with DASH scale and the Short form 36 (SF36) questionnaire for a subjective evaluation of upper limb disability and quality of life. All patients also underwent an instrumental evaluation with a hand-held dynamometer measuring hand grip and tripod pinch and a sensor-engineered glove test (SEGT) to evaluate finger opposition movements in a quantitative spatial-temporal way. As expected, we found significant differences between CMT and control group performances in both clinical and instrumental assessment. Concerning QoL, we found that total score of SF36 and the SF36 Physical Composite Score (PCS) correlate with all clinical and instrumental Outcome Measures (OMs), particularly with Tripod pinch strength and TOT, which are considered major determinants of manual dexterity in CMT. DASH scale correlates with most clinical and instrumental OMs. Not surprisingly, we also found a correlation with DASH work, because CMT affects young patients engaged in work activities. However, we found a low correlation with the TOT and the dynamometer suggesting that DASH may not be the best scale for remote monitoring of upper limb disorders in CMT patients. Nevertheless, the results of our study confirm the usefulness of SF36 in recognizing the impact of upper limb disability in these subjects suggesting its use even in the remote monitoring of physical functioning

The primary role of radiological imaging in the diagnosis of rare musculoskeletal diseases. Emphasis on ultrasound

Objective: In July 2017 a multidisciplinary clinical Center specialized in rare diseases was activated. A rare disease can involve the musculoskeletal system. A multimodality musculoskeletal imaging approach allows for a rapid diagnosis. The purpose of this study was to assess when musculoskeletal radiology, ultrasound in particular, plays a primary role in the diagnostic path of a rare disease. Methods and materials: The Center included a list of 621 main rare diseases. Pathologies in which radiology has a primary diagnostic role were extracted from the list. From September 2017 to January 2018 all conditions involving the musculoskeletal system, including the peripheral nervous system, were systematically evaluated by one radiologist. The second radiologist, an official consultant of the Center, verified the list for consistency. Descriptive analysis was performed. Results: A total of 101/621 (16%) rare diseases can be diagnosed for the first time in the diagnostic path of the patient with medical imaging. A total of 36/101 (36%) rare diseases involve the musculoskeletal system. A total of 14/36 (39%) are pediatric diseases, 10/36 (28%) are adult age diseases, while 12/36 (33%) diseases affect all ages. A total of 23/36 (64%) of the selected rare diseases could be diagnosed with MRI, 19/36 (53%) with CT, 23/36 (64%) with X-ray, 9/36 (25%) with an US, and 1/36 (3%) with PET. Conclusions: Musculoskeletal imaging could be important for a non-invasive diagnosis in up to 36/101 (36%) rare diseases, as well as for outcome prediction, especially in pediatrics. Musculoskeletal imaging plays a crucial role in the diagnosis of rare diseases and could strongly influence the clinical pathway. Ultrasound is crucial in up to 25% of patients with rare diseases affecting the musculoskeletal system

Respiratory involvement and sleep-related disorders in CMT1A: case report and review of the literature

Sleep-disordered breathing has been reported in Charcot–Marie–Tooth disease (CMT) type 1A in association with diaphragmatic weakness and sleep apnea syndrome, mainly of the obstructive type (OSA). Improvement has been observed not only in sleep quality but also in neuropathy symptoms in CMT1A patients with OSA following the initiation of continuous positive airway pressure. We report the cases of two siblings affected by CMT1A associated with hemidiaphragm relaxatio necessitating nocturnal non-invasive ventilation (NIV). Two twins, now 42 years old, with a family history of CMT1A, received a genetic diagnosis of CMT1A at the age of 16. Over the years, they developed a slowly worsening gait disorder and a decline in fine motor hand movements, currently presenting with moderate disability (CMTES:13). At the age of 40, they both started complaining of daytime sleepiness, orthopnea, and exertional dyspnea. They received a diagnosis of relaxatio of the right hemidiaphragm associated with impairment of nocturnal ventilation and they both have benefited from nocturnal NIV. Disorders of breathing during sleep may be underestimated in CMT1A since routine investigations of sleep quality are rarely performed. Our two clinical cases and a literature review suggest the importance of inquiring about symptoms of excessive daytime sleepiness and respiratory disturbances in individuals with CMT1A, even in the absence of severe neuropathy. In the presence of compatible symptoms, a pneumological assessment, along with an overnight polysomnogram and lung function tests, should be performed. Recognizing sleep-related symptoms is essential for providing accurate treatment and improving the quality of life for patients with CMT1A

Insulin-like growth factor-I prevents apoptosis in neurons after nerve growth factor withdrawal

Insulin-like growth factor-I (IGF-I) is emerging as an important growth factor able to modulate the programmed cell death (PCD) pathway mediated by the cysteine-dependent aspartate proteases (caspases); however, little is known about the effect of IGF-I after nerve growth factor (NGF) withdrawal in neurons. To begin to understand the neuronal death-sparing effect of IGF-I under NGF-free conditions, we tested whether embryonic sensory dorsal root ganglion neurons (DRG) were able to survive in defined serum-free medium in the presence of IGF-I. We further studied the role of IGF-I signaling and caspase inhibition after NGF withdrawal. NGF withdrawal produced histological changes of apoptosis including chromatin condensation, shrinkage of the perikaryon and nucleus, retention of the plasma membrane, and deletion of single cells. Both IGF-I and Boc-aspartyl (OMe)-fluoromethylketone (BAF), a caspase inhibitor, equally reduced apoptosis after NGF withdrawal. The antiapoptotic effect of IGF-I was completely blocked by LY294002, an inhibitor of PI 3-kinase signaling, but not by the mitogen-activated protein (MAP) kinase/extracellular signal-regulated protein kinase (ERK) activated protein kinase inhibitor PD98059. Functional IGF-I receptors were extensively expressed both in rat and human DRG neurons, although they were most abundant in the neuronal growth cone. Collectively, these findings indicate that IGF-I, signaling though the PI-3 kinase pathway, is important in modulating PCD in cultured DRG neurons after NGF withdrawal, and IGF-I may be important in DRG embryogenesis. © 1998 John Wiley & Sons, Inc. J Neurobiol 36: 455–467, 1998Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34477/1/1_ftp.pd

Early Detection of External Neurological Symptoms through a Wearable Smart-Glasses Prototype

The Internet of Things (IoT) framework is moving the research community to provide smart systems and solutions aimed at revolutionizing medical sciences and healthcare. Given the extreme diffusion of Alzheimer’s disease (AD) and Parkinson’s disease (PD), the demand for a solution to early detect neurological symptoms of such diseases strongly arose. According to the medical literature, such early detection can be obtained through the correlation between PD and AD and some external symptoms: the Essential Tremor (ET) and the number of Eye Blinks (EBs). In this paper, which can be considered as an extended version of [1], we present a prototype of wearable smart glasses able to detect the presence of ET of the head and to count the number of EBs at the same time, in a transparent way with respect to the final user. Numerical results demonstrate the reliability of the proposed approach: the proposed algorithms are able to i) correctly recognize the ET with an overall accuracy above 97% and ii) count the number of EBs with an overall error around 9%

Hand Rehabilitation Treatment for Charcot-Marie-Tooth Disease: An Open Label Pilot Study

Charcot-Marie-Tooth neuropathy affects mainly and early the lower limbs, but hands deformities are a relevant problem, which involves the quality of life of the patients. Unfortunately, there are few studies about the evaluation of the upper limbs and very rare works about the rehabilitation. A treatment study at the moment is missing and it is important to search rehabilitation exercises to improve the dexterity and the quality of life of the patients. METHODS: We recruited 9 patients with clinical and genetic diagnosis of CMT and we proposed a rehabilitation protocol which includes muscle recruitment, stretching and proprioceptive exercises for the hand with the duration of 4 weeks (two sessions for week). We evaluated the patients before and one week after the treatment with Thumb Opposition Test, Sollerman Hand Function Scale, dynamometry (tripod pinch and hand grip). RESULTS: The rehabilitation protocol has been well tolerated and there were not dropouts. We did not observe any worsening in every scale we used. Every parameter tested showed an improvement especially in the right/dominant hand. CONCLUSION: This study demonstrates that this three phases treatment is well tolerated by patients, it is not detrimental for the hands status and perfectly reproducible by professionals. Moreover, this could be the basis for future randomized single blind projects

Autoimmune central diabetes insipidus in a patient with ureaplasma urealyticum infection and review on new triggers of immune response

Diabetes insipidus is a disease in which large volumes of dilute urine (polyuria) are excreted due to vasopressin (AVP) deficiency [central diabetes insipidus (CDI)] or to AVP resistance (nephrogenic diabetes insipidus). In the majority of patients, the occurrence of CDI is related to the destruction or degeneration of neurons of the hypothalamic supraoptic and paraventricular nuclei. The most common and well recognized causes include local inflammatory or autoimmune diseases, vascular disorders, Langerhans cell histiocytosis (LCH), sarcoidosis, tumors such as germinoma/craniopharyngioma or metastases, traumatic brain injuries, intracranial surgery, and midline cerebral and cranial malformations. Here we have the opportunity to describe an unusual case of female patient who developed autoimmune CDI following ureaplasma urealyticum infection and to review the literature on this uncommon feature. Moreover, we also discussed the potential mechanisms by which ureaplasma urealyticum might favor the development of autoimmune CDI

Case Report: Post-COVID-19 Vaccine Recurrence of Guillain–Barré Syndrome Following an Antecedent Parainfectious COVID-19–Related GBS

Guillain–Barré syndrome (GBS) is an autoimmune neurological disorder often preceded by viral illnesses or, more rarely, vaccinations. We report on a unique combination of postcoronavirus disease 2019 (COVID-19) vaccine GBS that occurred months after a parainfectious COVID-19–related GBS. Shortly after manifesting COVID-19 symptoms, a 57-year-old man developed diplopia, right-side facial weakness, and gait instability that, together with electrophysiology and cerebrospinal fluid examinations, led to a diagnosis of post-COVID-19 GBS. The involvement of cranial nerves and IgM seropositivity for ganglioside GD1b were noteworthy. COVID-19 pneumonia, flaccid tetraparesis, and autonomic dysfunction prompted his admission to ICU. He recovered after therapy with intravenous immunoglobulins (IVIg). Six months later, GBS recurred shortly after the first dose of the Pfizer/BioNTech vaccine. Again, the GBS diagnosis was confirmed by cerebrospinal fluid and electrophysiology studies. IgM seropositivity extended to multiple gangliosides, namely for GM3/4, GD1a/b, and GT1b IgM. An IVIg course prompted complete recovery. This case adds to other previously reported observations suggesting a possible causal link between SARS-CoV-2 and GBS. Molecular mimicry and anti-idiotype antibodies might be the underlying mechanisms. Future COVID-19 vaccinations/revaccinations in patients with previous para-/post-COVID-19 GBS deserve a reappraisal, especially if they are seropositive for ganglioside antibodies

A novel mutation in the N-terminal acting-binding domain of Filamin C protein causing a distal myofibrillar myopathy

Variants in Filamin C (FLNC) gene may cause either cardiomyopathies or different myopathies. We describe a family affected by a distal myopathy with autosomal dominant inheritance. The onset of the disease was in the third decade with gait impairment due to distal leg weakness. Subsequently, the disease progressed with an involvement of proximal lower limbs and hand muscles. Muscle biopsy, performed in one subject,identified relevant myofibrillar abnormalities. We performed a target gene panel testing for myofibrillar myopathies by NGS approach which identified a novel mutation in exon 3 of FLNC gene (c.A664G:p.M222V), within the N-terminal actin-binding (ABD) domain. This variant has been identified in all affected members of the family, thus supporting its pathogenic role. Differently from previously identified variants, our family showed a predominant leg involvement and myofibrillar aggregates, thus further expanding the spectrum of Filamin C related myopathies