In recent days, there has been a lot of talk on social networks and mainstream press about a surgical procedure that is being carried out in a Shanghai hospital by a team led by Li Xia from the Faculty of Medicine of Shanghai Jiao Tong University, which could slow the progression of Alzheimer's disease, or even allow a temporary regression, in half of the participants.

Five weeks after the operation, clinical assessments revealed an improvement in cognitive function: the Mini-Mental Status Examination score went from 5 to 7, and the Clinical Dementia Rating-sum of boxes test score went from 10 to 8. The Geriatric Depression Scale score went from 9 to 0. The PET scan examination provided objective proof of this improvement.

This recent increase of interest is quite curious because a publication was made in June of this year by the team that innovated with this technique.

This study presents a new surgical procedure, neck shunting to unclog the cerebral lymphatic systems, aimed at improving the elimination of waste accumulated in the glymphatic system of the brain to manage Alzheimer's disease. The glymphatic system facilitates the removal of harmful proteins such as beta-amyloid and tau, the accumulation of which is linked to Alzheimer's disease.

The surgical procedure uses lymphatic-venous anastomosis (LVA) to decompress the cervical lymphatic trunk, allowing cerebrospinal fluid (CSF) and residual proteins to flow more efficiently from the brain into the venous system.

It is an extracranial procedure and therefore less invasive and potentially safer than intracranial methods. The surgical treatment, which involves four small incisions in the patient's neck, has been performed on at least 30 patients in two public hospitals in China. Other much larger numbers of patients treated are circulating on the Internet.

Early results indicate that the procedure holds promise as an innovative strategy for the prevention and treatment of Alzheimer's disease.

This surgical technique has not been considered for the treatment of Alzheimer's disease, or even the brain in general, but has been used for some time for other diseases such as lymphedema.

The field of lymphedema surgery has seen enormous progress over the years and has been associated with the rapid growth of super microsurgery techniques. A lymphovenous bypass or lymphaticovenular anastomosis requires the identification of residual lymphatic channels and the creation of an anastomosis on a recipient venule, thus allowing the flow of lymphatic fluid and the improvement of a patient's lymphedema.

A technique similar to that of Chinese doctors has long been used in the context of hydrocephalus. The cause of this disease is a blockage of cerebral-spinal fluids which leads to an accumulation of these fluids in the brain. Treatment for hydrocephalus then involves creating a way to drain the excess fluid from the brain.

In the long term, some hydrocephalus patients require a permanent cerebral shunt. This involves placing a ventricular catheter (a silastic tube) into the brain's ventricles to bypass the flow obstruction and drain the excess fluid into other body cavities, where it can be reabsorbed. Most shunts drain fluid into the peritoneal cavity (in the abdomen), but other sites include the right atrium (heart), pleural cavity, or gallbladder.

Hydrocephalus is known to cause Alzheimer's disease. Normal pressure hydrocephalus is common in elderly patients. Curiously, as Western physicians consider this hydrocephalus to be independent of Alzheimer's disease they are reluctant to operate on these patients because they believe the benefits are small.

The Chinese approach is the opposite. She believes that this accumulation of cerebrospinal fluid in Alzheimer's disease should be treated because, at the very least, it can temporarily relieve about two-thirds of patients. This pragmatic approach considers the patients and does not seek to demonstrate whether or not this accumulation causes Alzheimer's disease.

In a series of videos posted last month on social media, Cheng Chongjie, a doctor in Chongqing who adopted the technique following his colleagues, said the operation was effective in more than half of his patients.

"Two national medical centers have performed hundreds of LVA operations, and their results show that this procedure is effective in 60 to 80 percent of patients.

Spinal muscular atrophy (SMA) is a disease whose manifestations have some similarities with ALS, however, it has a well-identified genetic origin (SMN1 gene) and as a result, several drugs have been approved. These drugs improve the health of patients but have various drawbacks.

This rare disease causes the loss of motor neurons and progressive muscle atrophy. It is usually diagnosed in early childhood and, if left untreated, it often leads to death. It can also appear later in life and in this case the disease progresses more slowly.

The common feature is a progressive weakness of voluntary muscles, with the muscles of the arms, legs and airways being affected first. Associated problems can include poor head control, difficulty swallowing, scoliosis, and joint contractures. Although there is a large literature on the split hand phenomenon in ALS, knowledge remains limited for other motor neuron diseases, including SMA.

Early in ALS it is common for the thenar muscles (thumb muscles) to be affected and lose their usual volume, visually dividing the palm into two sections. This is oddly described as the split hand phenomenon or monkey hand phenomenon.

This phenomenon reflects the selective vulnerability of motor neurons characteristic of the disease. Conditions such as ALS, while also affecting motor neurons, tend to present with the classic split hand pattern, highlighting the differential pathophysiological mechanisms at play. However, the explanations for why these muscles are affected early in the disease are no clearer than in ALS. Furthermore, age-related atrophy can also present with the split hand phenomenon, complicating the diagnosis of ALS in older patients.

Muscle disuse is a common cause of muscle atrophy. The rate of muscle atrophy due to disuse is about 0.5% of total muscle mass per day. Older adults are most vulnerable to dramatic muscle loss with immobility. In SMA, as in ALS, loss of motor neuron function leads to muscle atrophy. A new study compared these losses in ALS and SMA.

To assess muscle loss in motor neuron diseases, the number of motor units is studied. A motor unit includes a motor neuron and all the skeletal muscle fibers innervated by the neuron's axon terminals, including the neuromuscular junctions between the neuron and the fibers. Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscle.

The number of motor units per muscle can change due to aging, disease, or injury.

Motor unit number estimation (MUNE) is a technique that uses electromyography to estimate the number of motor units in a muscle.

Motor unit number estimation (MUNE) methods, such as MScanFit MUNE, provide accurate results. This study uses MScanFit MUNE to compare patterns of motor unit loss in SMA, ALS, and healthy controls. Key findings include:

Patients with SMA had more severe degeneration of the hypothenar muscles compared to the thenar muscles. The authors call this: The reverse split-hand phenomenon, in reference to the split-hand phenomenon in ALS. Patients with ALS had a traditional split-hand phenomenon, with more severe involvement of the thenar muscles.

Reinnervation in SMA: Evidence of compensatory nerve sprouting in the ADM muscle has been noted in SMA but not in ALS, highlighting distinct pathophysiological mechanisms in these two diseases.

For SMA, the APB muscle has emerged as an optimal biomarker to monitor disease progression and therapeutic response due to its resistance to degeneration.

Curiously, although the authors confirmed the correlation between MScanFit MUNE neurophysiological parameters and disease severity in SMA patients, they did not find convincing correlations between MUNE neurophysiological parameters and clinical variables in ALS patients, particularly with the ALSFRS-R scale. On this issue, although several studies have reported the correlation between MUNE values ​​and the ALSFRS-R scale, others have not confirmed it.

Limitations and future directions The small cohort of AMS in the study and the lack of longitudinal data (over a period of several years) limit the conclusions. Future research should examine whether the reverse split hand phenomenon is exclusive to SMA and clarify why certain hand muscles are more vulnerable.

In this blog, I avoid studies that are not done on humans, firstly because the further away from humans and primates, the less sincere the scientific studies are. Then it is well known that the pre-clinical studies published are all extremely positive in order to attract investors (if possible private) who will finance clinical studies.

2,4-dinitrophenol (DNP)

The study examined here explores whether small doses of 2,4-dinitrophenol, a chemical used in the manufacture of pesticides and slimming drugs because it decreases the metabolic action of mitochondria, could help protect motor neurons, preserve muscle function and slow the progression of amyotrophic lateral sclerosis (ALS) in a mouse model of the disease. The scientists' guiding idea therefore seems to be to slow down the disease, by slowing down the metabolism. This seems absolutely counter-intuitive but the scientists assure that they have had good results. The effective dose of 2,4-dinitrophenol was very low (0.5–1 mg/kg, human equivalent dose 2.5–5 mg/day), making it safer for potential use in humans. Dinitrophenol acts as a proton transporter in the mitochondrial membrane, inhibiting oxidative phosphorylation of ATP and making energy production less efficient. This is because some of the energy that is normally produced from cellular respiration is wasted as heat. This inefficiency is proportional to the dose of dinitrophenol that is absorbed. Thus, as the dose increases, energy production becomes less efficient: metabolism is then activated - more fat is burned - to compensate for the inefficiency and meet energy demands.

The researchers used hSOD1G93A mice, a common model of ALS, to test the effects of 2,4-dinitrophenol on motor skills, muscle strength, and disease progression. However, it is important to remember that most ALS patients do not have this mutation and that its notoriety is simply because it was the first mutation to be associated with ALS and that for more than 10 years (from 1993 to 2006) no other deleterious mutations were discovered in ALS.

Results

Mice treated with microdoses of 2,4-dinitrophenol (0.5–1 mg/kg) showed better motor coordination and better results on tests measuring muscle strength, compared to untreated mice. Early treatment initiation (before symptoms appeared) delayed the onset of motor decline, while late treatment initiation (after symptoms appeared) improved motor skills (which were already impaired by the disease) and slowed disease progression. Treated mice retained their ability to perform tasks such as running at 20 cm/s for longer than untreated diseased mice. In some cases, the mice regained lost motor skills, which is unusual in ALS research.

Although ALS damages the connections between nerves and muscles (neuromuscular junctions), treatment with 2,4-dinitrophenol preserved these connections. Treated mice retained a higher number of motor units (groups of muscle fibers controlled by a single neuron), indicating that motor neuron loss was reduced.

Reduced Cellular Stress

2,4-dinitrophenol reduced oxidative stress, a harmful process linked to the progression of ALS. This was demonstrated by lower levels of damaged proteins in treated muscles. While ​​slowing down an ALS patient’s metabolism seems pretty criminal, reducing cellular stress is a very good idea.

The drug also reduced inflammation and activated pathways (like Akt/mTOR) involved in muscle growth and repair.

How would 2,4-dinitrophenol work?

2,4-dinitrophenol acts on mitochondria, the energy producers of cells, by slightly lowering their membrane potential (∆Ψm). This mild “uncoupling” reduces the production of harmful reactive oxygen species (ROS), which can damage cells. 2,4-dinitrophenol may also help clear damaged mitochondria and promote the formation of healthy mitochondria, further protecting neurons and muscles.

Future Directions

While the mouse results are promising, translating these findings to humans requires more research. The study also highlighted some limitations:

• It focused on one type of ALS model (hSOD1G93A) that affects less than 2% of patients.

• It did not address potential differences in drug responses between male and female mice, which could be significant.

• Administering a metabolic reducer to ALS patients still seems like a dangerous notion.

In recent years, research has shown that physical exercise has many benefits for the entire body, beyond muscle growth. There has been much discussion in recent years about the value of physical activity programs in the case of Alzheimer's or Parkinson's disease.

Researchers at MIT wrote about experiments that might lend credence to the idea that mechanical stimulation could one day be beneficial in ALS or other MND diseases.

Muscles release various biochemical factors, called myokines, which circulate in the bloodstream. These molecules establish a kind of dialogue between different tissues and this allows them to collectively adapt to a new environment. Myokine receptors are found in muscle, fat, liver, pancreas, bone, heart, immune system and brain cells. The location of these receptors reflects the fact that myokines have multiple functions. First, they are involved in the metabolic changes associated with exercise, as well as in the metabolic changes that follow adaptation to training. To study these effects specifically on motor neurons, the cells that transmit movement commands from the brain to muscles, MIT researchers developed a series of in vitro systems where they could precisely control and observe the effects of muscle contractions.

In 2023, Raman and his colleagues reported that they could restore mobility in mice that had suffered traumatic muscle injury by first implanting muscle tissue at the site of the injury and then exercising the new tissue by repeatedly stimulating it with light. Over time, they found that the exercised graft helped the mice regain motor function, reaching levels of activity comparable to those of healthy mice. This meant not only that the new muscle tissue had become functional, but also that there were somehow new connections between the lower motor neurons and the new muscles. In other words, the exercise was not only beneficial for the new muscle but also for the local motor neuron that develops synapses to connect to muscle fibers.

Then the group wondered: Could exercise’s purely physical impacts have a similar benefit on motor neurons?

This claim was met with some skepticism.

So the MIT team designed experiments in which the neurons were repeatedly pulled back and forth, similar to the way muscles contract and expand during exercise. Angel Bu is the first author, while Ritu Raman is the senior author; the other authors are from MIT’s Department of Mechanical Engineering and MIT’s Koch Institute for Integrative Cancer Research. The authors matured a set of motor neurons on a gel that was a kind of carpet into which they embedded tiny magnets. They then used an external magnet to shake the carpet—and the neurons—back and forth. In this way, they made the neurons work, for 30 minutes a day.

The researchers demonstrated that the physical force generated during muscle contraction has direct mechanical effects on motor neurons, promoting growth in both a biochemical and mechanical way. And the two effects, myokine release and motor neuron work, have similar effects.

These results could have important implications for the treatment of motor neuron diseases, such as amyotrophic lateral sclerosis (ALS) or spinal muscular atrophy, where motor neurons progressively lose their function. Therapies that mechanically stimulate muscle contractions could encourage nerve growth and regeneration, potentially slowing the progression of these diseases or facilitating recovery after nerve damage.

Of course, this study is extremely preliminary, it is carried out in vitro. We cannot even talk about micro-organs. This is basic research indeed, the authors didn't talk about applications in ALS/MND diseases. Another limitation of this study is that the authors did not explore a wide variety of mechanical or biochemical stimulation protocols with different frequencies, magnitudes, and durations.

If these mechanisms were confirmed in preclinical studies with primates and then clinical studies with humans, exercise protocols could be refined to maximize the biochemical and mechanical benefits for motor neurons, potentially improving motor function or slowing disease progression in patients with motor neuron diseases.

For example, patients could benefit from muscle stimulation devices that could help maintain or even regenerate motor neuron pathways. Mechanical muscle stimulation could indeed be a way to mimic the combined biochemical and mechanical effects of muscle contractions in patients with weakened muscles, potentially helping to slow neuronal degeneration or even stimulate nerve repair.

Electrical stimulators already exist for physiotherapy and rehabilitation, and future protocols could incorporate fine-tuning to produce exercise-like contractions that not only provide muscle benefits but also encourage motor neuron activity. Given that MND patients vary greatly in progression and severity, personalized electrical stimulation programs would be essential. Clinicians could develop individualized regimens, perhaps informed by biomarkers or real-time feedback, to maximize neuron growth-promoting effects without overloading the system.

Future research could test whether electrical muscle stimulation in MND patients produces benefits similar to biochemical and mechanical stimulation observed in vitro. If effective, this could lead to new physiotherapy protocols or devices aimed at improving the quality of life and motor function of people with MND.

Until Tofersen from Biogen, ALS drugs were only slightly slowing the disease. Tofersen aims to lower the levels of a specific mutation of SOD1. This therapy is probably a lifeboat for the patients with the matching SOD1 mutation. It's certainly slowing the disease progression, but only for a tiny portion of ALS patients less than 2%.

Not all patients with the right SOD1 mutation react to Tofersen similarly.

• People have two SOD1 genes in their cells and sometimes only one allele is mutated and the other can make up for the defective one. There are also other proteins named SOD2 and SOD3 that can assume partly the functions of SOD1.

• In the worst case with ASO medications, ALS patients are merely exchanging a defective protein with a lower production of the same protein. This is not a great perspective, a genetic therapy that makes cells produce the correct version of SOD1 would be better. Yet genetic therapies have their share of problems, including low efficiency and increased cancer risk.

All members of this protein family, transform a byproduct of the mitochondrial electron transport chain, into hydrogen peroxide and diatomic oxygen. Yet those two chemical species are themselves quite reactive. SOD1 is located in the cytoplasm of cells, SOD2 in their mitochondria, and SOD3 is extracellular.

In that case, where there is still one functional allele, it would be nice to check SOD1 levels in the body of patients treated with Tofersen. If it's too low (because of Tofersen) the therapy renders itself ineffective. This could be done by analyzing blood, but scientists reckon that checking SOD1 in CSF would be a better idea.

The discovery of children developing SOD1 Deficiency Syndrome (ISODDES) which is characterized by injury to the motor system, suggests that a too-low SOD1 antioxidant activity may be deleterious in humans. Measuring SOD1 activity in cerebrospinal fluid (CSF) in Tofersen-treated patients is recommended but difficult due to low concentration and the presence of the isoenzyme SOD3.

To assess SOD1 activity, the scientists propose to remove SOD3 from CSF samples with antibodies and subsequently measure the SOD1 activity. To propose this as a standard procedure for human beings is a bit weird. Repeatedly piercing the membranes that protect the spinal cord sounds like an unhealthy proposal, particularly if it's done to patients having motor neuron disease.

A recent publication provides a detailed overview of recent advances and challenges in the development of RNA therapies for neurodegenerative diseases, particularly for amyotrophic lateral sclerosis (ALS). Early immunotherapies targeting amyloid-β in Alzheimer's disease initially showed reductions in amyloid plaques but failed to prevent cognitive decline. The FDA recently approved lecanemab as the first disease-modifying drug for Alzheimer's disease. However, its benefits appear to be limited to the early stages of the disease, as it does not stop neurodegeneration or improve cognition. This highlights the difficulty of modifying neurodegenerative diseases, which often progress despite treatment.

Most cases of ALS are recognized as proteinopathies involving RNA dysregulation, but in others, such as those with mutations in superoxide dismutase 1 (SOD1), these abnormalities are absent, suggesting different pathogenetic pathways.

Nucleic acid-based therapies (NATs) represent an emerging treatment class that targets RNA rather than proteins. These agents act by degrading disease-associated mRNA or altering translation processes. For example, ASOs inhibit translation by disrupting ribosome assembly or degrading mRNA.

Although ASO approaches are both reasonable and scientifically sound, discernible clinical benefit has not always been observed in humans.

Three clinical trials using ASOs to reduce huntingtin (HTT) protein in Huntington’s disease have been halted because the therapies did not consistently reduce mutant HTT levels or improve clinical outcomes. A trial of one ASO, tominersen, caused unexpected worsening in patients who received higher doses. This has raised concerns about potential ASO toxicity due to off-target effects, immune responses, or loss of normal HTT function, which is essential for cellular health.

ASOs targeting toxic genes in ALS, such as TDP-43 in ALS, have shown promise in preclinical studies in extending life and restoring motor function in animal models. Yet, inhibitions of SOD1 and C9orf72 in mice show motor deficits and memory impairment over time, warning researchers of the potential risks of long-term ASO treatments. Clinical trials, such as the Phase III study of tofersen (an ASO targeting SOD1), have demonstrated a reduction in SOD1 mRNA, although clinical (i.e. visible) benefit has not been established.

Results from a Phase III trial of the ASO tofersen, which targets SOD1 mRNA in ALS, were reported in 2022. In this study, a total of 108 participants were enrolled, 60 of whom were classified in the faster progression subgroup. Approximately 7% of participants receiving tofersen experienced serious neurological adverse events, including myelitis, chemical or aseptic meningitis, and lumbar radiculopathy, but the pharmaceutical and medical community has highlighted the case of a Swedish patient who saw real benefit from his therapy.

A new study, ATLAS (NCT04856982), aims to test tofersen in asymptomatic, and some are thought to be presymptomatic, carriers of the SOD1 mutation to determine whether early intervention can delay the onset of ALS.

ASO-mediated inactivation in neurodegenerative diseases faces major challenges. By the time symptoms of ALS appear, motor neuron damage may be too advanced. Symptoms appear because compensatory mechanisms are exhausted. This is similar to Parkinson’s disease, where symptoms only appear after significant neuronal loss.

It is also likely that current ASOs are not very selective, and may reduce the production of essential proteins, causing side effects. Targeting mutations or aberrant transcripts specifically with more selective ASOs, such as those used in the PRECISION-HD trials, could help preserve healthy protein function.

Identifying sensitive biomarkers, such as elevated plasma TDP-43 or cryptic HDGFL2 levels, could help diagnose ALS before symptoms appear. This could allow for timely therapeutic interventions to slow or prevent neurodegeneration before it becomes irreversible.

In summary, RNA-based therapies such as ASOs offer hope for neurodegenerative diseases but face significant challenges.

In the case of neurodegenerative diseases, it is certainly more useful to try to develop new neuronal cells than to "cure" cells that we are told are dying or even dead for months. This is the purpose of regenerative medicine.

One of the difficulties is that neurons are cells that do not reproduce, we live with the stock that we had at the end of our puberty. These cells come from stem cells.

In our brain and the rest of the central nervous system, half of the cells are not neurons, but more classic cells that nourish and maintain neurons.

These cells reproduce by fission like most cells. In particular, astrocytes, although tiny, have many points in common with neurons. It is therefore natural to want to transform astrocytes into neuronal stem cells. Curiously, scientists are rather looking to directly convert astrocytes into neurons, despite the enormous morphological difference between these two types of cells.

A few years ago, following the discovery of Yamanaka factors, it was believed that this goal could be achieved quickly. However, the results obtained have been contested, in particular, because of methodological flaws. Despite the promising results of previous studies, the lack of robust lineage tracing methods has led to uncertainty as to whether the induced neurons originated from glial cells or whether native neurons were mistakenly labeled.

A new publication describes recent advances in converting glial cells into induced neurons in the central nervous system, particularly in regions where stem cell activity is limited. The previous “lineage reprogramming” approach used transcription factors to change the identity of terminally differentiated cells, such as glial cells, to other cell types.

The current study focuses on the transcription factor Ascl1, known for its role in neuronal fate decisions and its potential to reprogram various cell types into neurons. While Ascl1 can efficiently convert glial cells into induced neurons in vitro, its efficacy in vivo varies widely, often leading to limited neurogenic effects or, in some cases, inducing glial proliferation rather than neuronal conversion.

This inconsistency suggests that regulatory challenges affect Ascl1’s performance as a reprogramming factor, particularly due to context-specific modifications such as phosphorylation, which modulate its activity. Previous research has found that a mutant variant of Ascl1, known as Ascl1SA6, engineered to resist phosphorylation, enhances neurogenic activity, prompting this study to determine whether Ascl1SA6 could enhance glia-to-neuron reprogramming in vivo.

The researchers tested Ascl1SA6 in the early postnatal mouse cerebral cortex, which showed superior neuronal induction capacity compared to wild-type Ascl1. Furthermore, the combination of Ascl1SA6 with the survival factor Bcl2 further enhanced the efficiency of iN conversion. The study’s lineage tracing confirmed that the newly formed induced neurons were primarily from astrocytes. Interestingly, many of these induced neurons exhibited characteristics of fast-spiking parvalbumin-positive (PV+) interneurons.

In summary, the study demonstrates that Ascl1SA6, particularly in combination with Bcl2, could improve the efficiency and fidelity of glia-to-neuron reprogramming in vivo, with potential implications for therapies targeting neuronal loss and brain circuit restoration.

It should be kept in mind, however, that these cell type conversions a priori promote the appearance of cancers, that the new neurons are hardly useful, that the method used is gene therapy and therefore has very low efficacy and elevates cancer risks, that is is a report on experiences done in mice and they usually do not translate in humans and that it is not a question of conversion to neuronal stem cells which would be free of many of these problems.

Nevertheless, it's a step in the right direction.

Readers of this blog probably know the story of the drug NP001. One phase I and two phase II trials were conducted by Neuraltus in ALS patients (NCT01281631 and NCT02794857). These were both 6-month studies, the usual clinical trial duration. Phase 2A was completed in 2012, and Phase 2B in 2017. Both failed. Now some people want to revive this drug, through a new biotech named Neuvivo.

What the authors of a new publication did was to try to find a subset of patients that showed some longer survival with NP001 in those old trials.

This is a widely used technique by unsuccessful companies, but it is statistically meaningless.

The authors found a subset of patients who had inflammation and a longer survival. Yet this analysis would be comically wrong if we were not speaking of dying people. For example, the authors claim that survival of ALS patients with inflammation is 16 months longer than in the placebo arm. At 72 months there were only 3 people in the inflammation subset and two people in the placebo arm. Nobody can say anything about these numbers. If we use the same criteria, it shows that NP001 worsened the condition in all pALS with respect to the placebo branch, as starting from 72 months there were fewer survivors in the NP001 arm than in the placebo.

In addition, one could read the subset of pALS with inflammation as them having a comorbidity. If you prescribe an inflammation therapy to people having inflammation, they will improve a bit, which would be reflected in longer survival to ALS.

The proposed mechanism of action is vague (as usual, at least here there is a proposal): They said that NP001 is converted by macrophages to taurine chloramine, a regulator of inflammation. As the authors assert that persistent immune activation in patients with ALS is the cause of loss of muscle, an anti-inflammatory drug would help.

There are few publications about taurine chloramine, but, when taurine is in the presence of highly toxic hypochlorous acid, it generates the less toxic taurine chloramine. It's the result of the body's mitigation to a poison.