Neurology is a broad field and it deals with the diagnosis and treatment of disorders of the nervous system. Some diseases of the muscular system also belong to the field of neurology.
The nervous system is a very complex, highly specialised network of sensory and motor neurons and comprises the central nervous system (CNS) and the peripheral nervous system (PNS). It facilitates communication between all parts of the body and coordinates essential functions of the body’s response to both internal and external stimuli, thus enabling us to perform voluntary and involuntary actions (voluntary e.g. body movements and involuntary e.g. gland activation).
Since neurological diseases can affect all areas of the body, their symptoms are extremely variable. Many different factors can cause a neurological disease – infections, autoimmune diseases or dysfunction due to stroke and/or traumatic brain injury are just a few examples.
Neurological disorders or neurological deficits can cause considerable disturbances in movement control and lead to severe limitations in patients’ everyday way of life. Therefore, it is important to treat neurological disorders as early as possible. Although some neurological disorders are curable, others are not. However, it is often possible to positively influence or reduce the course and symptoms of a disorder through treatment.
With our therapy, we at Merz Therapeutics wish to contribute to improving the quality of life of patients with neurological disorders such as dystonia, spasticity and sialorrhea.
Dystonia is a neurological movement disorder charactised by involuntary muscle overactivity resulting in abnormal posture. There are patients with dystonia in every age group, whereas the disorder may appear in various forms and can affect different body parts. The causes of dystonia are not fully known. While an involvement of movement control centres is obvious, the cause might be found in various regions. It could originate, for example, in the cerebral cortex, basal ganglia, pyramidal tracts, or the medulla oblongata.
Characteristic symptoms are involuntary muscle spasms that trigger unusual body posture and movements. They can occur in different body parts, often in muscle groups of the head, neck, arms or legs. Dystonia is often focal, i.e. limited to one region of the body, such as eyelid spasm (blepharospasm) or a rotated neck (torticollis).
Spasticity is derived from the Greek word spasmós, meaning cramp. Damage to parts of the central nervous system (CNS) that control muscle activity can lead to spasms. This damage can arise from injury such as from traumatic brain or spinal cord injury. A medical condition such as a stroke, multiple sclerosis, cerebral palsy, a brain tumor, or brain damage that may be caused by oxygen deficiency, encephalitis or meningitis.
From a medical perspective, spasticity is a pathological increase in muscle tension. The hypertonicity in muscles leads to a permanent hardening and stiffening, known as spasticity. The degree of spasticity varies in terms of severity, as well as the accompanying symptoms. This is related to the areas of the CNS which are affected and to what extent. Symptoms are associated with functional impairments (e.g. hand function), restrictions in mobility, as well as limitations in everyday activities and quality of life.
Sialorrhea is defined as an uncontrolled excess of saliva due to an inability to clear the saliva from the mouth and/or increased saliva production (hypersalivation), resulting in constant drooling. Sialorrhea can cause the development of skin infections and rashes up to potentially life-threatening pulmonary infections (aspiration pneumonia). Furthermore, it can greatly impact quality of life in patients with neurological disorders such as Parkinson’s disease, stroke, traumatic brain injury and atypical parkinsonism. Affected individuals often feel embarrassed, which may lead to isolation, anxiety, depression and self-disgust. Despite this, sialorrhea is underdiagnosed and undertreated.
Botulinum neurotoxin is a very potent substance produced by bacteria. Botulinum neurotoxin attaches itself exclusively to nerve cells that activate the muscular system or specific glands – effectively and accurately blocking an overactive muscle or gland. The effect is reversible after a certain period of time (depending on dosage and injection location), so that repetition of the injection is typically necessary.