Motor Neuron Diseases
– An Overview
Motor neuron disease refers to a group of diseases that are caused by the degeneration of motor nerves and can lead variety of upper and lower motor neuron symptoms.
Motor neuron disease (MND) is a progressive disorder characterized by selective degeneration of motor nerves and weakness of muscles. The disease has poor prognosis and has poor life expectancy. The disease affects only motor neurons sparing the sensory system.
Motor Neuron Disease Causes
There is no conclusive evidence about the causative or risk factors for the disease.
Amyotrophic Lateral Sclerosis (ALS) is a form of MND which is characterized by fast progression and presence of both UMN and LMN symptoms in the trunk, extremities and bulbar regions. The life expectancy of patients with ALS is very poor of up to 3 to 5 years since the onset of the disease.
The onset of the disease may be from weakness in the extremities or symptoms of bulbar region. As the disease progresses the weakness spreads to all the regions.
Motor Neuron Disease Symptoms
- Weakness in the distal muscles of the extremities,
- fasciculations and cramps in all the parts of the body,
- emotional disturbances,
- alteration in tone.
- Reflexes may be exaggerated and Hoffmann's sign may also be positive.
ALS significantly hampers the quality of life of patients due to increased dependence for performing activities of daily living as the disease progresses.The presentation of the disease varies over several permutations of patterns of weakness and rate of progression.
The terminal symptoms of the disease are caused due to weakness of respiratory muscles leading to respiratory insufficiency and eventually respiratory failure Various
Some factors have been identified, which may responsible for poor prognosis, such as, presence of LMN features, old age, bulbar onset, low forced vital capacity (FVC) and low scores on revised ALS- functional rating scale (ALS-FRSr), other neurodegenerative disorders also present with similar UMN and LMN symptoms.
Motor Neuron Disease Treatment
Currently ALS is incurable. To improve the quality of life and complications developed secondary to prolonged and progressive muscle weakness, multidisciplinary care is required.
Commonly the management includes pharmacological intervention, rehabilitation, nutritional advice, good nursing care, artificial ventilator support in the later stages of the disease and Percutaneous endoscopic gastrotomy (PEG) preventing dysphagia related complications.
As multiple body systems are involved, the best approach is a multidisciplinary holistic management of the disease. Currently ALS is treated with a combination of medical, surgical and rehabilitative treatments.
Riluzole is the only medicine that has shown significant effect on the survival duration in ALS is Riluzole. Other medicines like Talampanel, Memantine, Cephalosporins, antioxidants, agents modulating apoptosis, anti-inflammatory medicines like Thaliomide and Celastol and Autophagy regulators like rapamycin and lithium are being tested with no conclusive results.
- Physiotherapy aims at improving the muscle power, normalizing the tone, gait training and functional thereby improving the quality of life.
- Occupational Therapy - The aim of occupational therapy is to teach functional ctivities, transfers, bed mobility skills required for activities of daily living. It also trains individuals with ALS to independently use wheelchair or other mobility aids.
- Speech and Language Therapy - A speech and language therapist helps with two of the most common symptoms – slurred speech (dysarthria) and swallowing problems (dysphagia).
- Certain aids and appliances such as canes for walking, modified utensils for eating, speaking aids may also be used by the individuals with ALS.
Cell therapy for Motor Neuron Disease
Cellular transplantation is an attractive management strategy for ALS/MND. The pre-clinical animal studies have shown benefits in the motor function. The safety of autologous stem cell transplantation has been established and allogenic cells transplantation is being studied. Transplantation of mononuclear cells derived from peripheral blood using various modes of transplantation like intracerebral, intra-spinal and intrathecal have shown beneficial gains in survival, respiratory function, muscle strength and bulbar impairment. It also slowed disease progression and rate of drop in the respiratory function.
Marked progressive axonal degeneration of motor neurons in the spinal cord and motor cortex is noted in ALS/MND. Currently the aim of transplantation is to protect the existing motor neurons and attempt to bring about regeneration and repair in the damaged motor neurons. BMMNCs have a neurogenic potential as well as neurotrophic influence on the nervous system and can home onto the site of injury. They further demonstrate immomodulatory, anti-inflammatory and cytoprotective properties. The growth factors like vascular endothelial growth factor, secreted by these cells bring about neoangiogenesis. These paracrine effects of BMMNCs transplantation lead to neuroprotection and subsequent alteration in the disease course and progression. These overall affects of stem cell transplantation helps in alleviating and halting the progression of the symptoms and regaining better quality of life in individuals with ALS.
Clinical results of Stem Cell Therapy at NeuroGen Brain and Spine Institute:-
We compared the survival duration of the ALS/MND patients treated with intrathecal autologous bone marrow mononuclear cells transplantation with patients that did not undergo intrathecal autologous BMMNCs transplantation. There were total 46 patients in the intervention group and 20 patients in the control group. Both these groups shared similar baseline demographic characteristics. Comparison of the survival duration suggested that the mean survival duration of the patients treated with intrathecal autologous BMMNCs transplantation was longer than those who were not treated (Table 1). The difference between the two was statistically significant (p=0.043). A clinically significant difference of 47 months in the survival duration suggests the potential of intrathecal autologous BMMNCs transplantation in the treatment of ALS/MND. Some patients were given stem cell therapy along with Lithium for 6 weeks. We noted that patients who were given Lithium and were young had better survival than the others. This could be attributed to better survival and growth of the transplanted cells.
Majority of the patients reported
- Clearer and louder speech,
- Improved tongue movements and
- Reduced speech fatigability.
- Bulbar symptoms like reduced chocking, improved swallowing, reduced saliva drooling,
- Increase respiratory capacity.
- Few showed better neck control.
- The limb function was better in few patients.
- Improvement in some patients showed improvement in the
- Lower extremity function,
- Fine motor activities,
- Static and dynamic standing and sitting balance.
All these changes were noted in the early post transplantation period.
Table 1: Survival analysis
Stem cell therapy in combination with standard rilutor and rehabilitation may lead to slowing down or halting of the progression in ALS/MND. It is safe, simple and efficacious in the earlier stages of the disease. There is also a possibility of improving bulbar symptoms like speech and swallowing with stem cell therapy. To the patients suffering from ALS stem cell therapy is the one of the hope for halting the progression.